Manufacture of Pipes or Tubes.
Year: 1886

page_text: This Specification was, upon the 3rd day of March 1888, amended under
Sections 18 to 21 of the Patents, Designs, and Trade Marks Act, 1883.
[The Amendments are shown in erased and italic type.]
Manufacture of Pipes or Tubes.
REINHARD MANNESMANN and MAX MANNESMANN, both of Remscheid, in the Empire
of Germany, manufacturers, do hereby declare the nature of this invention to be as
follows:-
This Invention is an improvement upon and further development of the method of
rolling solid or hollow blocks of metal which was communicated by us to Herbert
John Haddan and for which Letters Patent were granted to him last year, such
Letters Patent being dated January 27th 1885 No. 1167; and it relates to the making
of pipes or tubes out of solid metal by passing the blank once or several times through
to the rollers and, while doing so, imparting to such blank a rotatary motion between
the rollers.
Between two rollers, the axes of which are placed at an angle to one another, a block
of metal a is made to pass, having a rotatory and at the same time a longitudinal motion
imparted to it. In Fig. 1 A the rollers are shewn as being placed side by side to, in
Fig. 1 B as being placed above one another, and in Fig. 2 also they work beside each
other. In all the three arrangements, one roller revolves in a direction opposite to
that of the other. In Fig. 1A, the working takes place between the lateral, and in
Fig. 1B and 2 between the circumferential surfaces of the rollers. Towards the egress
the distance of the rollers from one another becomes less, so that the piece of metal
performs a spiral motion on emerging from the rollers A A, A' A'. For the purpose of
regulating the motion of the blank we provide lateral guides bb, Figs. 1 and 2, or friction
rollers c Fig. 3. The guides may also be longitudinally arranged, as shown in Fig. 4
and Fig. 5. These guides d d are made to rotate within the guide-bar b. The surface
line of the guides da may be rising towards the egress of the blank, as shewn in Fig. 4,
or towards the ingress thereof, as shewn in Fig. 5, or else they may be slanting in any
direction, as shewn in Fig. 6. The rotatory motion may be imparted to these guides
by the friction produced upon them during the progress of the blank or by any other
suitable means; and owing to the surfaces, with which the blank is brought.in contact,
varying constantly, the excessive heating is obviated and the surfaces may be readily
Γ

page_text: kept cool by water dropping thereupon or by other methods. When the blank a
Fig. 1 to 3 has been sufficiently heated to make it soft enough, or if it be possessed of
a sufficient degree of plasticity in ordinary temperature, and if during the passage
through the rollers a sufficient reduction of dimensions takes place, a transfer of
material from the centre towards the circumference of. the blank is effected, and by 5
external compressions or by displacement of molecules a pipe is formed without the
use of a core. Such would for example be the case if a cast steel billet of 1.8 inch be
worked and if the spiral threads performed by the blank be not too distant from each
other, so that, when the axis of rotation of the blank forms an angle of six degrees with
the roller, the blank of 1.2 inch advances 08 inch at every revolution. The dimension 1
of the hollow formed depends upon several circumstances, to wit-
1st. The proportion between the speed, at which the rotation takes place, and the
progress of the blank. The hole will be largest when there is a certain proportion
between the circular and the rectilinear motion which is determined by the nature of
the material, the temperature, the superficial area of the rollers, as well as their speed, 1
dimensions and position, the most suitable proportion being in each instance
ascertained by practice. As the proportion varies, the hole becomes less, until it
disappears altogether and the blank remains solid.
2. The position of the blank between the rollers. The more central the position of
the blank, the larger the hole will be, and conversely, until it disappears altogether 2
when the blank occupies a certain lateral position determined by the nature of the
material and by the temperature.
3. The proportion in which the dimensions of the blank are being reduced. The
formation of the hole only commences when a certain reduction takes place, and the
size of the hole and the proportion between its diameter and the external dimension of
the blank increases up to a certain limit, as the size of the blank is growing less.
4. The angle at which the surfaces of the rollers work together.
5. The twist of the fibres, and
6. The configuration of the surface of the rollers. Round or angular projections,
whether parallel or at an angle to the axis of the roller, facilitate the formation of the
hollow, because they tend to increase the superficial area of the roller. The adjust-
ment of the position of the rollers required for the purpose of varying the size of the
hole may be effected while the work is going on or during the intervals by means of
any suitable levers or hydraulic arrangements.
If a solid piece of metal be furnished with bevel ends, as shewn in Fig. 7. i, or if its
thickness be reduced in one or more places, as shewn in Fig. 8 i, and such piece of
metal be made to pass through the rollers in the manner set forth in the foregoing, it
becomes tubular in the parts that were originally thick and remains solid in those that
were reduced in size, as shewn in Fig. 7 ii and Fig. 8 ii. Pieces formed like Fig. 7 ii
may be used for railway shafts, as shewn in Fig. 9, and those formed like Fig. 8 ii
may be cut in several places and used for making grenades and for other purposes. In
the process described, the direction in which the pressure takes place remains constant
while the blank rotates, but the blank may be left unmoved while the direction of the
pressure rotates, or both may rotate or oscillate or perform any other motion either
jointly or severally. In the same way, the blank and the rollers may work at the
same speed or at different speeds, and in such cases the surfaces of the rollers slide
along the surface of the blank. By substituting working surfaces of a different nature
for the roller surfaces, the entire process may be performed by a sliding instead of a
rotatory motion of the working parts.
•
be
In those cases in which the blank was already hollow at the outset, the hole may
enlarged by proper adjustment of the position of the rollers while the process is going
on, and this enlargement may take place although the diameter of the blank itself is
being reduced, as shewn in Fig. 10. By the adjustment referred to, a centrifugal
tendency may be imparted to the material, by which the hole is enlarged. This
tendency may be turned to account for the purpose of enabling a core, tool or other
appliance to force its way into the solid metal, such core or other appliance remaining
either motionless or rotating, oscillating or moving in any other way, and being either

page_text: hot or cold or being cooled by water, air or gas, and the most suitable form of such
core or other appliance being determined in accordance with the cone formed between
the solid and the hollow portion of the blank while the progress of the operation is
suspended. By means of the core, a greater amount of smoothness may be given to
the hole produced or enlarged by the operation. A core C is shewn in Fig. 11. By
this core the blank a is prevented from sloping in the direction of its axis and
eventually rotates over it in the form of a pipe. The diameter of the finished pipe
may be equal to, larger or smaller than that of the orignal blank, but in practice the
adjustment is to be made in such a way as to add to the tendency of the hole to
enlarge itself. To this end the core or tool is made thicker at one end, as shewn in
Fig. 12.
As the hole grows larger, the centripetal tendency of the core increases, or in other
words, its axis seeks to identify itself with the axis of rotation of the blank, even
though the core had not been orignally inserted in the middle of the blank and even
though no hole could be formed without a core. If in the case of a long, solid blank
the core or tool be inserted first from one end and then from the other, in both
instances to half the length of the blank, the two holes formed will meet accurately
in the middle and become concentric, although the tool may originally have been
inserted excentrically; and thus long pipes may be made of which the sides have a
uniform thickness.
The working of the core or tool may be assisted and its wear and tear partly
counteracted by the centrifugal tendency of the material, owing to which a hole
spontaneously enlarges itself, even when no core, tool or "thorn" is used. In the
arrangement shewn in Fig. 13, the pipe, while being rolled, slides over the core d
which is fixed within the bearing fin such a way that it may revolve around its
own axis. The body of the core may be cylindrical or conical, or may be given any
other suitable shape. In the arrangements shewn in Fig. 11 and 12, the core works
by direct pressure only, whilst in Fig. 14 the core e is furnished with friction
rollers which tend to increase both the internal and the external diameter of the pipe.
These friction rollers ought always to be opposite to the rollers A A, and consequently
the core ought not to rotate in this arrangement. By varying the tendency to the
formation or enlargement of the hole, the pressure with which the material moves or
bears on the core may likewise be varied, and by this method a smooth and even a
polished surface may be given to the interior of the pipe.
If the thickness of the side of the pipe at its various stages of manufacture be not
very great in proportion to the internal or external diameter of the pipe, the round of
the core takes its share in the drawing-out, whereas in the case of the sides being thicker
in proportion, the function of the core is to give greater smoothness to the inside of the
pipe and to secure the perfect rotundity both of the inside and the outside of the
finished pipe. But if the side be very thin, the round of the core may tend to stretch
the pipe in the direction of the circumference; and if towards the egress of the pipe,
the distance of the rollers from one another become greater and the core thicker, an
enlargement of the external dimensions of the pipe may be readily achieved, provided
the proportions be appropriately chosen. As the outside diameter increases, the
diameter of the hole must increase in proportion, so that the sectional area of the pipe
at the egress is never greater, but mostly equal to or less than what it is at the
ingress, provided no special arrangements are made for varying the sectional area
in the longitudinal direction of the pipe. In the arrangements Fig. 12 and 15,
the core acts by pressure and in Fig. 16 by tension; and the best plan is to let it
rotate along with the pipe itself. When the core acts by pressure, the pipe in its
finished state moves on to the core; and when the core acts by tension, the pipe slips
automatically away from it. The shape of the core depends essentially on the cone
formed by the inclination of the rollers to one another, on the minimum dimension of
the blank and on the desired thickness of the sides of the pipe, and the best plan is to
find it out by experience for the various dimensions and materials.
In the screw and nut arrangement shewn in Fig. 5, the thickness of the sides of the
pipe may be varied by adjusting the position of the conic core, and it becomes easy in

page_text: such a case to find out the most advantageous position of the core. The correlative
position of the rollers may likewise be adjusted so as to secure the conicity most
suitable for adapting the rollers for any given core. The adjustment of the core in the
direction of its axis and the adjustment of the position of the rollers towards one
another may be effected between the hours of work or even while the work is going
on, by means of any of the well-known mechanical or hydraulic appliances. The
adjustment of the core in the direction of its axis is equally useful for bringing a
thicker portion of the core between the rollers when required.
If the shape shewn in Fig. 12, 14, 15, 16, 17 A and 17 B be given to the rollers, the
blank may be reduced in thickness by the first part of the rollers, provided its initial
thickness was less than the least distance of the rollers from each other; and by. the
second part of the rollers, its external dimension may be enlarged again. In this case
the least distance of the rollers from one another is at a point between the ingress and the
egress of the blank. If the front part of the blank has once been rolled into a hollow or
tubular form, as shewn in Fig. 12, 17 A and 17 B, or if such a tension has been induced
therein as to admit of a core being inserted, as in Fig. 12, pipes with thinner sides
may be made out of the solid blank at one passage through the rollers, either with
reduced, equal or increased external dimensions. In the arrangements Fig. 17 A and
Fig. 17 B the core has no other duty but that of enlarging the hole, the front of the
rollers having already given a tubular form to the blank. In Fig. 12, on the contrary,
the core also aids in forming the hole and in making its surface more smooth and
uniform at the initial stage.
When no core is used and the compression brought to bear on the blank from
without is in itself sufficient to produce the desired hole, the surface of such hole is
rendered smoother and more uniform by two agencies, to wit:-
1. The twist of the fibres-hereinafter called the frictional twist-which is
comparatively slight and is induced by the mere friction of the blank against the
rollers; and
2. The twist of the fibres-hereinafter called the heteroclitic twist-which is induced
by projections upon the surface of the rollers and by the grooving or roughing of such
surfaces. The more the fibres are twisted while the hole is being formed, the more
uniformi the surface of the hole must be; for the following reasons:-(a) All blisters,
honeycombs and other deformities in the material are drawn out and their injurious
character is proportionately reduced; (b) These irregularities assume a concentric
order; which neutralises the warping or deflection of the material, in a certain
measure at any rate, when it is being hardened. (c) While the rolling of the pipes is
going on, a rupture takes place at the mathematical centre and the hole.thus formed is
Being enlarged or the blank, while revolving between the rollers, is flattened out to
some extent: Owing to the fibres being constantly twisted or their position toward
Bach other being otherwise constantly changed, the material is always strained in one
direction or another, and the honeycombs, which under other circumstances would be
superadded to one another; constantly cross each other, and are thereby prevented from
obtaining a notable depth. If the dimensions and proportions be properly chosen in
accordance with experimental practice, pipes may be produced without the use of a
core, by the mere rupture of the interior, and in such a way that the sides of the hole
are comparatively smooth and perfectly free from blisters or honeycombs.
In the event of the material worked upon not being homogeneous, or of
there being irregularities, blisters or pores in billets or rough-rolled pieces;
or of the sides of pipes or tubes of any description not being of uniform thickness
throughout, the frictional or by preference the heteroclitic twist of the fibres may be
turned to account for the purpose of giving the sides of the finished pipes a uniform
thickness in every direction or of compelling an exactly central position of the core
While the rolling process is going on. By means of this twist the fibre of the metal or
other material may be stretched and reduced in thickness during the rolling, such
reduction being in excess of the reduction that takes place in the diameter of the
blank. By this method an amount of strength may be obtained even in the case of
thick pieces, such as could heretofore be obtained only in producing thin pieces by

page_text: roning; and in thick pieces better stretched and more uniform fibres are obtained, or
else a more delicate grain in the case of granular metals such as steel and iron.
If the blank be heated so rapidly that the interior remains cold and consequently
offers a greater resistance to torsion than the outside, the outside is twisted much
more sharply than the inside, when the material is subjected to a frictional or by
preference to a heteroclitic twist. In this case the fibres do not merely undergo a rope-
like twist around the longitudinal axis of the blank, but the external layers of the
material which have the same cross section also undergo a marked displacement
towards the corresponding internal layers. By this means, blisters, honeycombs or
similar irregularities are extended in the direction of the periphery and compressed in
such a way as to assume an approximately concentric order. By applying the break
or reducing the speed at which the thicker portion of the blank rotates, the internal
layers may have a more or less sharp twist given to them in proportion to the external
layers.
In those cases in which the fibres of a blank have been twisted in one direction and
a twist in the opposite direction is imparted to them at the following operation, the
first twist is wholly or partly neutralised by the second, and the stratification of the
fibres that results therefrom, will be straight, curvilinear, zigzag or otherwise shaped,
according to circumstances. The second twist may also be effected in one heat with
the first, if two or more sets of rollers be worked in succession, or if different
directions be given to the motion of the various portions of the same set of rollers or
different speeds imparted to them, as will be the case when the blank, after it has been
inserted between the rollers, first rotates slowly, then is made to revolve at a more
rapid rate and eventually has its speed reduced again towards the egress. In Fig. 18
this stratification of the fibres is illustrated in the shape of a pipe rolled out of a solid
block and having remained solid at one end. The lines are intended to shew how in
such a case the fibres first turn to the right and then to the left.
A second twist of the fibres in a direction opposite to that of the first twist also
takes place if the first rollers cause the piece to rotate at a uniform speed, while the
second rollers cause it to rotate at a gradually reduced rate of speed. Such is the case,
when conic rollers or rollers in the shape of face-plates are used. With some materials
the process may be repeated ad indefinitum, so much so that very complicated
configurations may be produced thereby.
If in the case of oblique rolling, that is to say when a rotatory and at the same time
rectilinear motion is imparted to the blank, or in the case of cross-rolling-that is to
say if the blank be rolled while revolving between two rollers moving in opposite
directions, but without the blank progressing automatically-projections or notches be
made on the surface of the rollers, to admit of the blank being grasped more firmly
there is an approximate uniformity in the superficial speed of the blank and of the
rollers in the points of contact, and there is less sliding and consequently less wear
and tear of the rollers; it also becomes easier to draw the blank into the rollers. If in
the arrangement Fig. 20 the cone at the back of the rollers be formed very gradually,
a solid blank mayibe rolled into a pipe of a larger diameter even without using a core;
and if the solid blank be properly gauged, it may even be made into a thicker solid
piece between the rollers. It stands to reason that the two processes may be merged
into one, that is to say the operation of drawing out a thick piece to narrow.
dimensions and that of thickening a piece of smaller dimensions. When this is
to be done, the rollers must be so gauged and turned-while leaving the rest of.
the apparatus untouched-that towards the egress the material will proceed at a
less rapid rate than in its thinnest part. This is effected by means of sharp
projections made on the surface of the rollers and gearing, as it were, into the
blank, thereby forcing the material back. This process can also be expedited by
artificially reducing the speed at which the blank rotates, in proportion to that of
the. movement of the rollers. The projections shown in Fig. 20. become narrower
towards the egress, and it is best to choose the proportions in such a way that
the projections always bear upon the corrugations upon the surface of the blank,
which are nearer to the egress. By passing once through these rollers, the fibres

page_text: of the blank grow more interwoven and the structure of the metal becomes more
homogeneous. This method of rolling produces practically the same effect as is
achieved in the case of refined steel by repeated welding in packets and by other
kindered operations. The process may also be used for welding iron, for the purpose of
relieving it more completely of scoria by drawing out very thin while twisting its
fibres at the same time.. In this case, the result is more favorable than it is with
very thick blanks, and yet the piece worked upon may in the end be rolled solid or
hollow to exactly the required diameter.
Hitherto it has been necessary to make the sides of gas pipes very much thicker
than they need have been to stand the pressure for which they are calculated, lest
there would not remain material enough beneath the threads after the screws had been
cut at the ends. Gas pipes with very thin sides may; by the process herein set forth,
have their sides made thicker at the ends by hydraulic or other suitable mechanical
means, and the screw threads may then be cut at the ends without affecting the safety
of the pipe by this means, a great saving is also obtained in the weight of the pipes.
The screwed parts may also be fixed at the ends, so that the cutting operation becomes
unnecessary. In that event, the coupling box may be made to run along the entire
length of the pipe; and in the same way as in the case of the ends of the pipes, the
screw threads may be fixed on to the coupling boxes, which themselves may consist of
cuttings of pipes. In Fig. 32 a gas pipe is shewn with screw threads projecting at
the ends at the outside, whilst in Fig. 33 the female screw threads are shewn as
projecting at the inside of the pipe.
If in the case of pipes made without a welded seam according to any of the usual
methods, the cylindrical shape be changed into an oval or other shape by means of a
hydraulic press or by any other mechanical appliance, or if screw or other shafts be
made thereon, the pipes, in yielding to the pressure applied from within or from without,
may be lengthened or shortened or generally have their dimensions altered either
longitudinally or transversely or in both directions. So long as this change does not
go beyond the limit of the strain to which the material may be exposed with safety,
the operation may be repeated. In the case of steam boilers, the motion produced in
the steam pipes by the variation of the steam pressure causes the sediment to break
and loosen itself of its own accord, so that, after it has reached a certain thickness, it
may readily be removed in pieces. In Fig. 19 a pipe is shewn which having been
drawn and twisted out at one end by the variations in the pressure of the steam, has
acquired a tendency to spontaneously break off the sediment that has accumulated.
In all the arrangements constructed according to our Invention, as herein before
described and illustrated in the accompanying sheet of drawings, no more than one
blank is worked upon by the rollers. By a modification in the application of our
Invention, we are enabled to roll two or more blanks between one set of rollers,
especially in those cases in which the dimensions of the blanks are small and the
diameter of the rollers is large. Thus, in Fig. 21, two blanks are shewn as being
rolled simultaneously between the rollers A, A. The best arrangement in cases of
this kind is to place one of the two rollers above the other and the blanks a a by the
side of one another on one and the same table. The friction rollers c c are working
within the lateral guides bb, while the two blanks a a are separated from one another
by the intermediate guide f, to which the form of a friction roller may also be given.
This guide f, however, is not indispensable, and if it be suppressed, the blank will
spontaneously seek to bear upon the friction roller that corresponds to it.
For the friction rollers c c Fig. 21, fast guides bb Fig. 22 may be substituted or
other similar appliances may be used in lieu thereof. In the arrangements shewn in
Fig. 21 and 22, two blanks are rolled simultaneously, whilst in Fig. 23, 24 and 25,
three or more blanks may be worked upon at the same time. Even in the arrange-
ments Fig. 21 and 22, three or more pieces might be rolled together, only it would
not be possible to give them all the same diameter, neither would it be possible in the
arrangement shewn in Fig. 23. If a set of three rollers be used and the work be
always performed between two rollers, as in Fig. 24 and 25, it will be possible to
obtain two, three, four or six points in which as many as six blanks may be rolled

page_text: simultaneously. The work may also be performed alternately in two or more different
points of the roller system, and while the second blank is being rolled, there is time
enough to remove the first blank that has been rolled at the other point, and to get
ready a new blank in the place thereof. By this means the time during which the
motor does no effective work may be reduced to a minimum and even to nil.
If in oblique rolling the blank is prevented from performing a rotatory or rectili-
near motion corresponding to the motion of the surface of the rollers, it is
made to slide or slip upon the rollers. In that event, those projections
or notches on the surface of the rollers which are not strictly peripheral,
have a tendency to produce a transposition of the surface of the blank, while
projections that move forward and rise towards the egress tend to propel the
material in such a way that the outside of the blank proceeds at a quicker rate than
the inside. Under certain circumstances a hollow body is then formed which may in
certain cases remain closed behind. On the contrary, those projections that work back-
ward and are widened towards the ingress, tend to push the material near the surface
backward, while the inside or the thin end seeks to advance; by this means there
arises an accumulation of the material in the larger section. A tension may also be
produced within the blank, both longitudinally and transversely, by which a drawing-
out or tubular formation of the material may be induced or promoted.
In those cases in which the angle formed by the inclination of the two rollers
towards one another is very large, or in which this angle is suitably chosen, or in
which a sufficient reduction of the dimensions of the blank takes place to cause the
thick end thereof to be seriously impeded in its progress, while the thin end, owing
to its friction against the rollers or the projections upon the surfaces of these is
propelled forward with a great tensile power, a tensile strain may be induced between
the thick end and the thin end, by which a saving of motive power may be effected
or the rolling process be facilitated, just as in the case of ordinary longitudinal rolling
smaller rollers require less motive power than larger ones, because at a less pressure
the fibres are apt to be displaced and drawn out to greater lengths.
•
To reduce or increase the speed at which the blank moves, in proportion to the
speed of the roller, surfaces, provision can be made for applying the brake to or
accelerating the motion of the blank, and the same effect can be produced by stopping,
fixing or moving a core working within the blank or by the steep inclination of the
rollers towards each other or by any other suitable method. By applying the break to
the core, its rotatory motion in regard to the blank may be readily and efficiently varied,
which is a great advantage in the case of a core being furnished with screw-threads,
also because it greatly reduces the wear and tear of the core.
The best way of
applying the break to the blank itself is by increasing its friction against the guides or
the friction rollers. If the core be furnished at its thicker end with projections or
screw-threads placed at an angle to its axis and made steeper towards the rear, and if
its rotatory motion be different from that of the pipe itself, all these circumstances
together may tend to increase the speed at which the pipe moves over the core, and in
the same way the tensile strain induced in the pipe longitudinally may tend to draw
the pipe out and to make its sides thinner.
If, in rolling pipes out of solid pieces of metal, a core be used of which the
diameter is less than the diameter of the intended hollow, and if the core be brought
sufficiently forward in the direction of the motion of the blank, it is not necessary that
the core or tool should have a sharp point, but its point may be dull or rounded off.
In that case the core, instead of splitting up the material within the blank, rather tends
to produce a compression of the material in the interior, enabling it to more closely
follow the outward tension or, yielding to the pressure of the core, to bulge in an
outward direction where the pressure is less than within. In Fig. 26 a core of this
description is shewn at work. In this case, the blank touches the core only in front,
because the hole that is being produced is greater than the diameter of the core.
In those cases in which the core is prevented from rotating, it need not be round. In
such like cases, the highest points of the core are opposite to the rollers. The core
consists of one or several pieces; it may be furnished with an exchangeable point and

page_text: may be wholly or partly solid or else hollow altogether. In this latter case the hole
may be turned to account for the purpose of introducing liquids or semi-liquids within
the hollow formed in the blank, also for the purpose of keeping the surfaces cool. In
Fig. 27, an oval, hollow and immovable core is shewn, at the top of which there is a
series of lateral holes, through which water, oil or other refrigerants or lubricants may
be allowed to issue. A modification is shewn in a longitudinal section in Fig. 28.
Here, the body of the core consists of two tubes, one working inside the other. The
refrigerating material passes through the intermediate spaces between the two, entering
through the one and oozing out through the other. The inside tube may be continued into
the working part of the core, and the cooling liquid may be introduced either through
the interior or the exterior tube.
When cores are used without cooling appliances, a deformation of the core takes
place while the work is proceeding, especially in those cases in which the diameter of
the blank is small. Such deformation is determined by the variation of the dimen-
sions of the blank as well as by its progress. If both be calculated and adjusted in
such a way that the conicity of the core corresponds to the form that is to be given to
it, the deformation of the core will be less and the wear and tear it undergoes by
friction against the blank more gradual and consequently less perceptible. Inas-
much as, owing to the effect produced by the oxide between the blank and the core,
small particles of the interior of the tube frequently detach themselves and adhere to
the core, the wear and tear of the core may be neutralised altogether. Thus, the core
may even grow longer and thicker, so that it may be necessary to grind it down from
time to time. If the reduction of the diameter and the rate of speed of the blank be
properly proportioned, while the form given to the core is defective, the core is in
course of time worn down until it reaches the desired form and the strain upon it is
.diminished.
In Fig. 29. an arrangement is shewn in which three or four rollers bear simul-
taneously upon the same blank. In this case the blank is self-guiding, and conse-
quently the guides shewn in previous arrangements may be dispensed with. But if
pipes are to be rolled out which are smaller than the space that remains clear when the
rollers touch each other, it becomes necessary to so arrange the rollers that they can
gear into each other. The way in which this is done is shewn in Fig. 30, whilst
Fig. 31 shews the position which the rollers occupy towards one another. The best
plan is to let the projections of two rollers that are opposite to one another, bear upon
the same circumference, while the two other rollers likewise work opposite to each
other, but within the grooves formed upon the first pair. In this way, every portion
of the blank, while moving forward, is worked upon alternately by two rollers laid
horizontally and by two set at a right angle to the two others.
In the process of oblique rolling, one end of the blank is always finished right off
by constant rotation and repeated drawing-out, before the other end enters the rollers.
To prevent the other end from getting cold, the blank may be placed within a heating
apparatus fitted in front of the rollers in such a way that while the rolling process is
proceeding, the rollers gradually draw the blank out of the heating apparatus. This
appliance may be given any suitable form; it may for example consist of a simple
tube or of a double tube with intervening asbestos, and the heating be effected by
means of appropriate gases within the tube or tubes. In most instances, the heat
yielded by a number of blanks placed within the heating apparatus is sufficient to give
it the desired temperature, so that the loss of heat that would otherwise ensue prior
to the blanks entering the rollers is considerably decreased. The heating apparatus
may stand still, or it may rotate together with the pipe, or may have any other motion
imparted to it.
Inasmuch as the rotatory speed of the blanks may be considerably increased in the
case of oblique rolling, it is advisable to fit, both in front and behind the rollers, an
appliance by which the blank is prevented from performing a jerking movement, such
as would naturally ensue directly the blank is bent in any way. The object may be
achieved in fitting in front and behind the rollers a tube of which the interior diameter
is somewhat greater than the diameter of the blank. Such-like guide tubes, rings or

page_text: rollers may consist of one or of several pieces, fitted into or upon one another; or in
the place thereof other suitable appliances may be used which may be stationary or
rotatory or have any suitable motion imparted to them. The flexibility of a core
within a narrow guide tube being limited, long pipes may be drawn out even with the
aid of a thin and more flexible core.
For the oblique rolling process described in the foregoing, by which solid or hollow
bodies, rotating and at the same time progressing in a straight line, are drawn out
or rolled between rollers moving almost in opposite directions, a cross rolling process
may in some instances be substituted, that is to say a process by which the blank is
caused to rotate between surfaces moving in directions opposite to one another, without
there being at the same time a rectilinear progress of the blank. In this process, the
blank having been placed parallel or oblique or at a right angle between the rollers
that are continuously or periodically brought closer to or removed further away from
one another, rotates between these rollers, its axis being thus either parallel or oblique
or perpendicular to the axes of the rollers; and when the rolling process has been
finished, the rollers may be put at a greater distance from one another, for the purpose
of removing the blank in its finished form and putting another in its place. The
arrangement may also be made in such a way that the rollers remain always at equal
distance from one another and that the blank is placed between and removed from the
rollers, by suitable mechanical or hydraulic appliances, either in a direction parallel to
the axes of the rollers or at a right or acute angle to these axes. If the blank be
inserted laterally, one roller has a greater speed imparted to it than the other, and thus
the blank is drawn out by means of friction between the rollers, mechanical or other
suitable appliances being used for that purpose.
In the cross-rolling process, the same as in the oblique-rolling process, solid blanks,
if their dimension be suitably reduced, may be rolled in a hollow or tubular form or
partly solid and partly hollow. In this case the method of making and enlarging holes
is the same as in the case of oblique rolling. But whereas in oblique rolling the
blank is gradually and automatically brought nearer to the narrowest point, in cross
rolling the two rollers are gradually brought nearer to one another by mechanical
means or else the blank is by similar means brought gradually closer to the spot at
which the rollers are closest to each other.
Both in oblique and in cross rolling, the core may have a motion imparted to it in
the axis of rotation of the blank, with a view to the formation of hollow bodies or
for the purpose of smoothing, drawing-out or enlarging them. In such cases, a
forward or backward motion may be given to the core, or else it may be made to rotate,
oscillate, vibrate or move in any other suitable manner.
If in cross rolling the blank is to be given a motion parallel to the axes of the
rollers, a piston may be used for that purpose, which may be moved by steam, by
water or by any other suitable mechanical appliances. Similar appliances may be used
in the case of oblique rolling, when heavy blanks are to be inserted between or removed
from the rollers and human power is not found adequate to achieve this or too much
time would be required for that purpose. The drawing-in of the blank may likewise
be rendered more secure and accurate by means of a stamp, when the incline of the
rollers has been chosen too steep; and by the same method the motion of the
material over the core may be accelerated or the enlargement of the pipes be
facilitated.
When the oblique rolling process is performed with cylindrical, conical or other
rollers, as shewn in Figures 1 B, 2, 3, 10, 11, 12, 13, 14, 15, 16, 17 A, 20, 21, 22, the
mechanical power is brought to bear upon the ingress of the blank and the egress is
opposite to the spot at which the working of that power takes place. By this method,
the length of the finished pipes is rendered, as it were, independent of the size of the
space between the transmission shaft and the rollers, so that pipes of very great length may
be rolled and arrangements more efficiently made for exchanging the cores. However,
the mechanical power may equally well be caused to operate at the egress. In Fig. 23
an arrangement is shewn in which the working surfaces of face-plate rollers may be
given any suitable form and the operation takes place in a transverse direction to the
B

page_text: axes of the rollers. In this case, three blanks are worked simultaneously. When
face-plates, conic, convex or concave discs are used, the blank may be introduced at
that end of the rollers or discs which describes a smaller circle and it may emerge at
the larger circumference (Fig. 1 A and Fig. 17 B); or else the blank may pass over
from the larger circumference or from the part of the roller that describes the larger
circle, to the smaller circumference. In the former case the rotation of the surface of
the blank increases continuously, in the latter it is gradually reduced.
If two apparatus of this description be placed one behind the other, so that the
blank must pass through both, the speed at which the blank rotates may be gradually
increased in the first and gradually reduced in the second apparatus. An initial
increase with subsequent reduction of the speed at which the blank rotates may be
obtained even with one set of rollers, if the point at which the rollers are closest to
one another, be between the ingress and egress, as shewn in Figures 12, 17 A, 17 B
and 20. If that speed is to be first reduced and then accelerated, the face-plate
arrangement must be used. The foregoing process of rolling solid blanks into pipes
without the use of a core can be applied without a subsequent smoothing process only
in those cases in which the diameter of the blank
very small or in which the thickness
of the sides of the pipe is to be very great.
The second process of rolling hollow tubes by the aid of a core or a tool can also be
employed only in a few instances, because it would involve too much expense to make
the hollow according to the methods hitherto in use. A real saving of expense can
only be obtained by a combination of the two methods, that is to say by rolling solid
blanks without a core, and by rolling hollow or perforated bodies to pipes or tubes in
one or in several operations. For this purpose we first roll the blanks according to
the first method, and then, after heating them once more, pass them through rollers
according to the second method, whereby they are made into perfect pipes or tubes
suitable for practical uses. The two processes, with and without core, may even be
carried out in one heat, two or more sets of rollers being fitted up in succession to, or
by the side of, one another; and such sets of rollers may be identical to or differ from
one another in their construction. The rough-rolling without a core and the finishing
operation with a core may be combined in one and the same apparatus, as shewn in
Fig. 17 A and 17 B. In this case, a hollow is first obtained in the blank which was
originally solid, while the second portion of the rollers finishes the operation by the
aid of a core, whereby the sides of the pipe are made thinner and both the internal and
external diameters enlarged..
By the rough-rolling process which forms the first part of the operation, the inside
of the pipe is not rendered smooth, because some of the detached fibres or crystals remain
projecting upon the surface and are subsequently flattened down by the motion of the pipe
over the core. But if, by keeping the inside of the pipe hermetically sealed against
the atmosphere, an oxidation of those particles be prevented, they may in the course
of the operation of the core, be perfectly welded on to the sides of the pipe, provided
the temperature be such as to admit of such welding, such temperature being propor-
tionately low in the event of the oxidation of the aforesaid particles of iron or steel
having been guarded against, so that the desired effect is obtained, in the case of iron
or steel, at the early stage of yellow or even of red heat, and defects that may have
arisen by the rolling are entirely remedied by the welding operation alluded to. If
the core shuts off the finished piece of pipe sufficiently from the hollow space formed
by hollow rolling and being either a perfect vacuum or filled with innocuous gases,
the inside may readily be made smooth by welding; and the access of atmospheric
air may equally be prevented by suitable gases being conducted to the spot. By using
any kind of flux or by heating the pipe up to welding heat, the sides may be made
smooth and perfect even if air be admitted.
By means of a suitable selection of dimensions of both the inside and outside
of the pipe and the thickness of the core, the extent to which the outside of the core
bears upon the inside of the pipe may be sufficiently reduced to prevent the core from
being heated and worn and the inside of the pipe from being cooled more than is
absolutely necessary. The same object may also be achieved by means of projections

page_text: upon the outside of the pipe and by the use of lubricants and of non-conductors of
heat. The smoothness and rotundity of the pipe may also be increased by reducing
the enlargement of the pipe towards the egress.
The last finishing touch may be given to the pipe by passing it through two or
more rollers or discs of suitable form, fitted up behind the rolling mill proper, and
Disc-shaped rollers running upon
acting either independently or as draw-rollers.
supporting axles may be used for finishing the polish of the pipes and may be arranged
in a row, by the side of or above one another, in sets of one, two or more discs. The
polishing rollers or discs which produce their effect either by a rolling or a sliding
friction or partly by one and partly by the other, may be used in connection with both
polishing materials and lubricants, and the polishing operation may also be performed
separately from the rolling process.
JOSEPH THEODORE DANN,
32, Canterbury Road, Brixton, S.W.,
Agent to the Applicants.

page_text: עטקט
Improvements in the Construction and Use of Apparatus for the
Manufacture of Pipes or Tubes.
REINHARD MANNESMANN and MAX MANNESMANN, both of Remscheid, in the
Empire of Germany, manufacturers do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This Invention relates, to the making of pipes or tubes out of solid or hollow metal
by passing the blank once or several times through diagonally-acting rolls or rollers
and, while doing so, imparting to such blank a rotatory as well as an end wise motion
between the rollers. It is an improvement upon and a further development of the
method of rolling solid or hollow blocks of metal which has been communicated by us
to Herbert John Hadden and for which letters-patent have been granted to him, such
letters-patent being dated January 27th 1885, No. 1167.
mainly in working upon the outside of a solid blank by external rolls or rollers in
Our process consists
such a manner that the blank is ruptured along the line of its axis and forced to
assumes a tubular shape, either no core or mandrel being used in such cases, or else a
core or mandrel being employed for the purpose of smoothing the inside of the pipe
or tube thus formed, reducing the thickness of its sides or shell, and enlarging its
internal diameter.
An ingot or block of metal a is made to pass between two rolls or rollers, the axes
of which are placed at an angle to one another, in such a way that the block of metal
has thereby a rotatory and at the same time time a longitudinal motion imparted to it.
In Fig. 1 A the rollers are shewn as being placed side by side, in Fig. 1B as being
placed one above the other, and in Figures 2 and 3 also they work beside each other.
In Fig. 1 A the rolling process is performed between the lateral surfaces of two
disc-rolls A A, which revolve in opposite directions to one another and are placed at
slightly different heights. In Figures 1 B, 2 and 3 the rollers A' A' impinge upon
the blank with their circumferential surfaces, while their axes are inclined in opposite
directions to one another. Thus, a rotatory and at the same time a longitudinal motion,
or in other words a spiral movement, is imparted to the blank in all these arrangements,
by the manner in which the rolls impinge upon it. A conoidal form being given to
the rolls, in such a way that towards the egress of the blank their distance from each
other is reduced, it is obvious that the blank itself, as it passes between the rolls, is
progressively reduced in diameter. For the purpose of keeping the blank in its proper
position during its progress through the rolls and preventing its lateral deviation, we
provide guides or other suitable appliances which will be referred to hereinafter.
When the blank a, Figures 1 to 3, has been sufficiently heated to make it soft
enough, or if it be possessed of a sufficient degree of plasticity in ordinary temperature,
and if, during its progress through the rolls, a sufficient reduction of its dimensions
takes place, a transfer of material from the centre towards the circumference of the

page_text: blank may be effected and by external compressions or by the displacement of
molecules a pipe or tube can be formed without the use of a core or mandrel. Such
will, for example, be the case, if a cast-steel billet of 18 inch diameter be worked and
if the spiral threads performed by the blank be not too distant from each other, so that,
when the axis of rotation of the blank forms an angle of six degrees with the roller,
the blank of 12 inch advances 0.8 inch at every rotation. The dimension of the
hollow formed depends upon several circumstances, to wit:-
1st. The proportion between the speed, at which the rotation takes place, and the
progress of the blank. The hole will be largest when there is a certain proportion
between the circular and the rectilinear motion which is determined by the nature of
the material, the temperature, the superficial area of the rollers, as well as their speed,
dimensions and position, the most suitable proportion being in each instance ascertained
by practical experience. As the proportion varies, the hole becomes less, until it
disappears altogether and the blank remains solid.
2. The position of the blank between the rollers. The more central the position of
the blank, the larger the hole will be, and conversely, until it disappears altogether
when the blank occupies a certain lateral position determined by the nature of the
material and by the temperature.
3. The proportion in which the dimensions of the blank are being reduced. The
formation of the hole only commences when a certain reduction takes place, and the
size of the hole and the proportion between its diameter and the external dimension of
the blank increases up to a certain limit, as the size of the blank is growing less.
4. The angle at which the surfaces of the rollers work together.
5. The twist of the fibres, and
6. The configuration of the surface of the rollers. Round or angular projections,
whether parallel to the axis of the roller or at an angle thereto, are apt to facilitate
the formation of the hollow, because they tend to increase the superficial area of the
blank. For the purpose of varying the size of the hollow, the position of the rollers
may be adjusted while the work is going on, or during the intervals, by means of
suitable levers or hydraulic arrangements.
If a solid piece of metal be furnished with bevel ends, as shewn in Figure 7 A, or
if its thickness be reduced in one or more places, as shewn in Figure 8 A, and such
piece of metal be made to pass through the rollers in the manner set forth in the
foregoing, it grows tubular in the parts that were originally thick and remains solid
Pieces formed
in those that were reduced in size, as shown in Figures 7 B and 8 B.
like Figure 7 B may be used for railway shafts, as shewn in Fig. 9, and those formed
like Figure 8 B may be cut in several places and used for making grenades and for
other purposes. In the process described, the direction in which the pressure takes
place remains constant while the blank rotates, but the blank may be left unmoved
while the direction of the pressure rotates, or both may rotate or oscillate or perform
any other movement either-jointly or severally. In this way The tubular formation
in a billet may be produced or developed by a mere rotary motion without end wise
movement of the blank between revolving or oscillating rolls or other rolling devices,
but the impingement of the rollers upon the blank, or the reduction in the diameter of
the blank, must be sufficient to effect the rupture of the blank along the line of its
axis and to induce a movement of the material from the centre in an outward direction.
The blank or piece to be rolled may perform any other motion that may be decired
between the rollers, besides the aforesaid rotatory motion; it may, for example, have
an endwise oscillatory movement produced by suitable mechanical appliances. In the
same manner, the surface of the blank and of the rollers may work at the same speed
or at different speeds, and in the latter case the surface of the rollers may slide along
the surface of the blank. By substituting dies or other working surfaces of a different
nature for the roller surfaces, the entire process may be performed by a sliding instead
of a rolling movement of the working parts, but in such cases the blank must also be
impinged upon on opposite sides by such dies or sliding tools, and its diameter be
redneed thereby.
In those cases in which the blank was hollow at the outset, the hole may be enlarged

page_text: way, and
by the proper adjustment of the position of the rollers while the process is going on,
and this enlargement may take place although the diameter of the blank itself is
being reduced as shewn in Fig. 10. By the adjustment referred to, the material may
have imparted to it a tendency to assume a tubular formation, whereby the hole is
enlarged. This tendency may be turned to account for the purpose of enabling a core,
mandrel or other appliance to force its way into the solid metal, such appliance
remaining either motionless, or rotating, oscillating, or moving in
any other
being either hot or cold, or being cooled by water, air, or gas, and the most suitable
form of such mandrel being determined in accordance with the cone formed between
the solid and the hollow portion within the blank, while the progress of the operation
is suspended. By means of the core or mandrel, a greater amount of smoothness
may be given to the hole produced or enlarged by the operation. The mandrel C
shewn in Fig. 11 is prevented from sloping sliding in the direction of its axis, and the
blank rotates over it in the form of a pipe. The diameter of the finished pipe or tube
may be equal to, larger or smaller than that of the original blank, but in practice the
adjustment is to be made in such a way as to add to the tendency of the hole to enlarge
itself. To this end, the core or mandrel is made thicker at one end, as shewn in
Fig. 12. Owing to the tendency of the material to assume a tubular shape, the axis
of the core or mandrel seeks to identify itself with the axis of rotation of the blank,
even though the core had not been originally inserted in the middle of the blank, and
even though no hole could be formed without a core; for the middle of the metal
representing the path of the smallest resistance, the core enters the metal at that path.
If in the case of a long solid blank the core or mandrel be inserted first at one end
and then at the other, and in both instances to the extent of half the length of the
blank, the two holes formed tend to meet accurately in the middle and to become
concentric, although the tool may originally have been inserted eccentrically; and by
this means long tubes may be produced of which the sides have a uniform thickness.
The working of the mandrel or tool may be assisted and its wear and tear partly
counteracted by the tendency of the material to assume a tubular formation under the
action of the exterior rolls, by reason of which tendency the hole spontaneously
enlarges itself, even when no core, mandrel or "thorn" is used. In the arrangement
shewn in Fig. 13, the pipe, while being rolled, slides over the core or mandrel d which
may be fitted within the bearing fin such a way than it may, or may not, revolve
around its own axis. The body of the core may be cylindrical or conical, or it may
have any other suitable shape given to it. In the arrangements shewn in Figures 11
and 12, the core works by direct pressure only, whilst in Fig. 14 the core e is furnished
with friction rollers rr which also tend to increase both the internal and the external
diameter of the tube, such friction rollers being especially suited for the rolling of
large-size tubes. These friction rollers require to be always opposite to the rollers A A,
and consequently the core or mandrel ought not to have a rotatory motion in this
arrangement. By varying the tendency to the formation or enlargement of the hole,
the pressure with which the material moves or bears on the core may likewise be
varied, and by this method a smooth or even polished surface be given to the interior
of the tube.
If the thickness of the sides or shell of the tabe at its various stages of manufacture
be not very great in proportion to the internal or external diameter of the pipe or
tube, the round of squeeze between the rollers and the core or mandrel takes its share in
the drawing-out, whereas in the case of the sides or shell being thicker in proportion,
the function of the core is to give greater smoothness to the inside of the tube and to
secure the perfect rotundity both of the inside and the outside of the finished pipe. In
the case of the shell being thinner the round of squeeze on the core or mandrel may
tend to stretch the pipe or tube in the direction of the circumference; and if towards
the egress of the pipe the distance of the rollers from one another become greater and
the core thicker, an enlargement of the external dimensions of the pipe may be readily
achieved, provided the proportions be appropriately chosen. As the outside diameter
increases, the diameter of the hole must increase in proportion, so that the sectional
area of the pipe or tube at the egress is never greater, but mostly equal to or less than

page_text: what it is at the ingress, provided no special arrangements are made for varying the
sectional area in the longitudinal direction of the pipe. In the arrangements Figures 12
and 15, the mandrel gives pressure to the mandrel-shaft, and in Fig. 16 it imparts
tension thereto; and the best plan is to let it rotate along with the pipe itself. When
the mandrel acts by pressure, the pipe or tube in its finished state moves on to its
shaft and when the core acts by tension, the pipe slips automatically away from it.
The shape of the core or mandrel depends essentially on the cone formed by the
inclination of the rollers to one another, on the minimum dimension of the blank and
on the desired thickness of the pipe, and the best plan is to find it out by experience
for the various dimensions and materials.
In the screw-and-nut arrangement shewn in Fig. 15, the thickness of the sides of
the pipe may be varied by adjusting the position of the conic mandrel, and it becomes
easy in such a case to find out the most advantageous position of the core or mandrel.
The correlative position of the rollers may likewise be adjusted so as to secure the
conicity most suitable for adapting the rollers to any given mandrel. The adjustment
of the position of the rollers-towards one another may be effected between the hours
of work or even while the work is going on, by means of any of the well-known
mechanical or hydraulic appliances. The end wise adjustment of the core in the
direction of its axis is equally useful in any oblique-working tube-rolling mill for
bringing a thicker portion of the core or mandrel between the rollers when required.
If the shape shewn in Figures 12, 14, 15, 16, 17 A and 17 B be given to the rollers,
the blank niay be reduced in thickness by the first part of the rollers, provided its
initial thickness exceeded the minimum distance of the rollers from each other; and
by the second part of the rollers, its external dimension may be enlarged again. In
this case,
the least distance of the rollers from each other is at a point between the
ingress and the egress of the blank. If the front part of the blank has once been
rolled into a hollow or tubular form, as shewn in Figures 12, 17 A and 17 B, or if
such a tension has been induced therein as to admit of a core or mandrel being
inserted, as in Fig. 12, pipes or tubes with thinner sides may be made out of the solid
blank at one passage through the rollers, either with reduced, equal or increased
external dimensions. In the arrangements Figures 17 A and 17 B the core has no
other duty but that of enlarging the hole, the front of the rollers having already given
a tubular form to the blank. In Fig. 12, on the contrary, the core also aids in forming
the hole and in making its surface more smooth and uniform at the initial stage.
When no core or mandrel is used for producing the tubular formation, and the
compression in the exterior of the blank is in itself sufficient to produce the desired
hole, the surface of such hole is rendered smoother and more uniform by two agencies,
to wit:
1st. The twist of the fibres-(hereinafter called the frictional twist)-which is
comparatively slight and is induced by the mere friction of the blank against the
rollers; the diameter of each roller standing bearing to that of the blank in a
different greater proportion at the egress from what than it does at the ingress, as
shewn in the drawings; and
2. The twist of the fibres-hereinafter called the heteroolitic twist-which is induced
by projections upon the surface of the rollers and by the grooving or roughing of such
surfaces. The inore the fibres are twisted while or before the hole is being formed,
the more uniform the surface of the hole must be, mainly for the following reasons:-
(a) All blisters, honey combs and other deformities in the material are drawn out and
their injurious character is proportionately reduced; (b.) These irregularities assume a
concentric order, which neutralises the warping or deflection of the material, in a
certain measure at any rate, when it is being hardened (e). While the rolling of the
pipes or tubes is going on, a rupture takes place at the mathematical centre, and the
blank, while revolving between the rollers, is flattened out to some extent. Owing to
the fibres being constantly twisted or their position towards each other being otherwise
constantly changed by this flattening, the material is always strained in varying
directions, and the honeycombs, which under other circumstances would be superadded
to one another, constantly cross each other, and are thereby prevented from obtaining
:

page_text: a notable depth. No overstraining of the material is produced, however, if the fibres
of the blank are overlaid spirally around the axis. If the dimensions and proportions
be properly chosen in accordance with experimental practice, pipes or tubes may be
produced without the use of a core, by the mere rupture of the interior, and in such a
way that the sides of the hole are comparatively smooth and perfectly free from
blisters.
In the event of the material worked upon not being perfectly homogeneous, or of
there being irregularities, blisters or pores in billets or rough-rolled pieces, or of the
sides or shell of pipes or tubes of any description not being of uniform thickness
throughout, the frictional, or, by preference the heteroclitie twist twist of the fibres
may be turned to account for the purpose of giving the sides of the finished pipes a
uniform thickness in every direction, or of compelling an exactly central position of the
core while the rolling process is going on. By means of this twist the fibre of the metal
or other material may be stretched and reduced in thickness during the rolling, such
reduction being in excess of the reduction that takes place in the diameter of the blank.
By this method an amount of strength may be obtained even in the ease of thick
pieces, such as could heretofore be obtained only in producing thin pieces by rolling,
and in thick pieces better stretched and more uniform-fibres are obtained, or-else-n
more delicate grain in the case of granular metals, such us steel and iron.
If the blank be heated so rapidly that the inside thereof remains colder and
consequently offers a greater resistance to torsion than the outside, the outside is
twisted much more sharply than the inside, when the material is subjected to a
frictional or by preference to a heteroclitic twist. In this case the fibres do not merely
undergo a rope like twist around the longitudinal axis of the blank, but the external
layers of the material which have the same cross section also undergo a marked
displacement towards the corresponding internal layers. By this menus, blisters,
honeycombs or similar irregularities are extended in the direction of the periphery and
compressed in such a way as to assume an approximately concentric order. -By
applying the break or reducing the speed at which the thicker portion of the blank
rotates, the internal layers may have a more or less sharp-twist given to them in
proportion to the external layers.
In those cases in which the fibres of a blank have been twisted in one direction, and
a twist in the opposite direction is imparted to them at the following operation, the
first twist is wholly or partly neutralised by the second, and the stratification of the
fibres that results therefrom will be straight, curvilinear, zigzag or otherwise shaped,
according to circumstances. The second twist may also be effected in one heat with
the first, if two or more sets of rollers be worked in succession, or if different directions
speeds be given to the motion circumference of the various portions of the same set of
rollers or different speeds be imparted to them, as will be the ease when in such manner
that the blank, after it has been inserted between the rollers, first rotates slowly, then
is made to revolve at a more rapid rate and eventually has its speed reduced again
towards the egress. In Fig. 18 this stratification of the fibres is illustrated in the
shape of a pipe or tube rolled out of a solid blank and having remained solid at one
end. The lines are intended to shew how in such a case the fibres first turn to the
right and then to the left.
A second twist of the fibres in a direction opposite to that of the first twist also
takes place if the first rollers cause the blank to rotate at a uniform speed, while the
second rollers cause it to rotate at a gradually diminishing rate of speed. Such is the
case when conic rollers, or rollers in the shape of face-plates or discs are used. With some
materials, the process may be repeated ad infinitum,so much so that a very complicated
configuration may be produced thereby.
If in the case of oblique rolling, that is to say when a rotatory and at the same time
rectilinear motion is imparted to the blank, or in the case of cross-rolling-that is to
say when the blank is rolled while revolving between two rollers moving in a
peripheral direction, but without the blank progressing automatically-projections or
notches be made on the surfaces of the rollers to admit of their impinging more
firmly on the blank, there is an approximate uniformity in the superficial speed of

page_text: the blank and of the rollers in the points of contact, and there is less sliding and
consequently less wear and tear of the rollers; it also becomes easier to draw the
blank into the rollers. If in the arrangement Figure 20 the cone at the back of the
rollers be formed very gradually, a solid blank may be rolled into a pipe or tube of
a larger diameter oven without the use of a core or mandrel; and if the solid blank
be properly gauged, it may even be made into a thicker solid piece between the rollers.
It stands to reason that the two processes may be merged into one, that is to say the
operation of drawing out a thick piece to narrow dimensions and that of thickening a
piece of smaller dimensions. When this is to be done, the rollers must be so gunged
and turned while leaving the rest of the apparatus untouched that towards the
egress the material will proceed at a less rapid rate than in the thinnest part. This
may be effected by means of sharp projections made on the surface of the rollers and
impinging upon, or gearing, as it were, into the blank, thereby foreing the material
back. This process may also be expedited by artificially reducing the speed at which
the blank rotates, in proportion to that of the movement of the rollers. The
projections shewn in Fig. 20 become narrower towards the egress, and it is best to
choose the proportions in such a way that the projections always bear upon the corru-
gations on the surface of the blank which are nearer to the egress. By rassing once
through these rollers, the fibres of the blank grow more interwoven and the structure
of the metal becomes more homogeneous. This method of rolling produces practically
the same effect as is achieved in the ease of refined steel by repeated welding in
packets and by other kindred operations. The process may also be used for welding
iron, for the purpose of relieving it more completely of seoria by drawing out very
thin while at the same time twisting its fibres. In this case, the result is more
favourable than it is with very thick blanks, and yet the piece worked upon may in
the end be rolled solid or hollow to exactly the required diameter.
Hitherto it has been necessary to make the sides of gas pipes very much thicker
than they need be for the pressure they are intended to stand. The reason of this is
that if the sides were thinner, there would not remain material enough beneath the
threads after the corewe have been cut at the ends. Gas pipes with very thin sides
may have these made thicker at the ends by hydraulic or other suitable mechanical
means, and the serow threads may then be eut at the ends without the safety of the
pipe being endangered thereby; a great saving may also be obtained by this method
in the weight of the pipes. The serewed parts may also be affixed to the ends, so
that the cutting operation becomes unnecessary. The coupling box may be made to
run along the entire length of the pipe ; and in the same way as in the ends of the
pipes, the screw threads may be fixed on to the coupling boxes, which themselves may
consist of cuttings of pipes. In Fig. 32, a gas pipe is shown with screw threads
projecting at the ends outside, while in Fig. 33 the female serew threads are shewn
as projecting at the inside of the pipe.
If in the ease of pipes made without a welded coam; according to the hereinbefore
described or any other suitable method, the cylindrical be changed into an oval or
other shape, by means of a hydraulic press or any other mechanical appliance, or if
screw or other shafts be made thereon, the pipes, in yielding to the pressure applied
from within or from without, may be lengthened or shortened, or generally have their
dimensions altered, either longitudinally, or transversely, or in both directions. So
long as this change does not go beyond the limit of the strain to which the material
may be exposed with safety, the operation may !
y be repented. In the case of steam
boilers, the motion produced in the steam pipes by the variation of the steam pressure
enuses the sediment to break and loosen itself of its own accord, so that, after it bas
reached a certain thickness, it may readily be removed in pieces. In Fig: 10 a pipe is
shewn which having been drawn and twisted out at one end by the variations in the
pressure of the steam, has acquired a tendency to spontaneously break off the sediment
that has been accumulating
In all the arrangements constructed according to our Invention, as herein before
described and illustrated in the accompanying cheet of drawings, no more than one
blank is worked upon by the rollers. By a modification in the application of our
о 11

page_text: Invention, we are enabled to roll two or more blanks between one set of rollers,
especially in those cases in which the dimensions of the blanks are small and the
diameter of the rollers is large. Thus, in Fig. 21, two blanks are shewn as being
rolled simultaneously between the rollers A' A. The best arrangement in cases of
this kind is to place one of the two rollers above the other, and the blanks a. a by the
side of one another, on one and the same table. The friction rollers c c are working
within the lateral guides bb, while the two blanks a a are separated from one another
by the intermediate guide f, to which the form of a friction roller may also be given.
This guide f, however, is not indispensable, and if it be suppressed, the blank will
spontaneously seek to bear upon the friction roller corresponding to it.
For the friction rollers c c Fig. 21, fast stationary guides bb Fig. 22 may be substituted,
or other similar appliances may be need in lien thereof. In the arrangements shewn in
Figures 21 and 22, two blanks are rolled simultaneously, whilst in Figures 23, 24
and 25 three or more blanks may be worked upon at the same time. Even in the
arrangements Figures 21 and 22, three or more pieces might be rolled together, only
it would not be possible to give them all the same diameter, neither would it be
possible in the arrangements shewn in Fig. 23. If a set of three rollers be used, and
the work be always performed between two rollers, as in Figures 24 and 25, it will be
possible to obtain two, three, four or six points, in which as many as six blanks may
be rolled simultaneously. The work may also be performed alternately at two or
more different points of the roller system, and while the second blank is being rolled,
there is time enough to remove the first blank that has been rolled at the other point,
and to get ready a new blank in place thereof. By this means the time during
which the motor does no effective work may be reduced to a minimum, and even
to nil.
.
If in oblique rolling the blank is prevented from performing a rotatory or reetilinear
motion, corresponding accurately to the motion of the surface of the rollers, it is made
to slide or slip upon the rollers. In that event, these projections or notches on the
surface of the rollers which are not strictly peripheral have a tendency to produce a&
transposition of the surface of the blank, while projections that move forward and rise
towards the egress tend to propel the material in such a way that the onteide of the
blank proceeds at a quicker rate than the inside. Under certain circumstances, a
hollow body is then formed which may in certain cases remain closed behind. On the
contrary, these projections that work backward and widen towards the ingress, tend
to push the material near the surface backward, while the inside or the thin end seekė
to advance by this means there arises an accumulation of material in the larger
section. A tension may also be produced within the blank, both longitudinally and
transversely, by which a drawing out or tubular formation of the material may be
induced or promoted.
In those cases in which the angle formed by the inclination of the two-rollers
towards one another is very large, or in which this angle is suitably chosen, or in
which a sufficient reduction of the dimensions of the blank takes place to cause the
thick end thereof to be seriously impeded in its progress, while the thin end, owing to
its-friction against the rollers or against the projections upon the surfaces of these, is
propelled forward with a great tensile power, a tensile strain will be induced between
the thick and the thin end by which a saving of motive power may be effected or the
rolling process be facilitated, just as in the case of ordinary longitudinal rolling smaller
rolls require less motive power than large ones, because at a less pressure the fibres
are apt to be displaced and drawn out to greater lengths.
To reduce or increase the speed at which the blank moves, in proportion to the
speed of the roller surfaces, provision can be made for applying the break to, or
accelerating the motion of the blank, and the same effect can be produced by stopping,
fixing, or moving a core or mandrel working in the blank, or by the steep inclination
of the rollers towards each other, or by any other suitable method. By applying the
break to the core or mandrel, its rotatory motion in regard to the blank may be
readily and efficiently varied, which is a great advantage in the case of a core being
furnished with screw threads, also because it greatly reduces the wear and tear of the

page_text: core. The best way of applying the break to the blank itself is by increasing its
friction against the guides or the friction rollers. If the core or mandrel be furnished
at its thicker end with projections or screw-threads placed at an angle to its axis, and
made steeper towards the rear, and if its rotatory motion be different from that of the
pipe or tube itself, all these circumstances together may serve to increase the speed at
which the pipe or tube moves over the core or mandrel, and in the same way the
tensile strain induced in the pipe longitudinally may tend to draw the pipe out and to
make its sides thinner.
If, in rolling pipes out of solid pieces of metal, a core be used of which the diameter
is less than the diameter of the intended hollow, and if the core be brought sufficiently
forward in the direction of the motion opposition to the advance of the blank, it is not
necessary that the core or mandrel shall have a sharp point, but its extremity may be
dull blunt or rounded off. In that case the core or mandrel, instead of splitting up
the material of the blank, rather tends to produce a compression of the material in
the interior, thereby enabling it to more clearly the better to follow the outward tension
or, yielding to the pressure of the core, to bulge in an outward direction where the
pressure is less than within. In Fig. 26 A, a core or mandrel of this description is
shown at work. The blank here touches the mandrel only in front, because the hole
that is being produced is greater than the diameter of the mandrel.
Instead of the tubular formation and the compression of the of the sides or shell of
the inchoate pipe or tube being performed by one set of rolls, two sets of rolls acting
in succession to one another may be used. Fig. 26 B illustrates an arrangement of
this kind. In this case, two diagonally-acting rollers A A, are used to transform a
solid blank into a tube, and another pair of rollers B B, are employed to receive the
tube formed by the rolls A A, and compress the thickness and weld the interior
surface of such tube, thereby converting the blank D into a finished tube d¹.
In those cases in which the core or mandrel is debarred from rotating, it need not
be round. In such like cases, the highest points of the core or mandrel are opposite
to the rollers. The mandrel consists of one or several pieces; it may be furnished
with an exchangeable point, and may be wholly or partly solid, or else hollow
altogether. In this latter case, the hole may be turned to account for the purpose of
introducing liquids, or semi-liquids, in the hollow formed in the blank, also for the
purpose of keeping the surfaces cool. In Fig. 27, an oval, hollow and immovable
core is shewn, at the top of which is a series of lateral holes, through which water,
oil or other refrigerants or lubricants may be allowed to issue. In Fig. 28, a modifi-
cation is shown in a longitudinal section. Here, the body of the mandrel consists of
two tubes, one working inside the other. The refrigerating material passes through
the intermediate spaces between the two, entering through one and going out through
the other. The inside tube may be continued into the working part of the core,
and the cooling liquid may be introduced either through the interior or the exterior
tube.
When cores or mandrels are used without cooling appliances, they are subject to
deformation while the work is proceeding, especially in those cases in which the
diameter of the blank is small. "Such deformation is determined by the variation of
the dimensions of the blank, as well as by its progress. If both be calculated and
adjusted in such a way that the conicity of the core or mandrel corresponds to the
form that is to be given to it, the deformation of the core will be less, and the wear
and tear it undergoes by friction against the blank more gradual and consequently
less perceptible. Inasmuch as, owing to the effect produced by the oxide between the
blank and the core, small particles of the interior of the tube frequently detach them
selves and adhere to the core or mandrel, the wear and tear of the mandrel may be
neutralised altogether. Thus, the mandrel may even grow longer and thicker, so
that it may be necessary from time to time to grind it down. If the reduction in the
diameter and the rate of speed of the blank be properly proportioned, while the form
given to the core is defective, the core is, in course of time, worn down until it reaches
the desired form, and the strain upon it is diminished.
For the purpose of regulating the motion of the blank during the progress of the

page_text: tubular formation, we provide lateral guides shewn in several of the views such as
Figures 1, 2, 22 and 253, in which they are marked bb, or friction rollers cc, as
shewn in Figures 3 and 21. The guides may also be longitudinally arranged; in
a frame, as shewn in Figures 4 and 5. These guides, marked d d, are made to
rotate within the guide-bar b. The guides d d may be fitted so as to rise towards
the egress of the blank, as shewn in Fig. 4, or towards the ingress thereof, as shewn in
Figure 5, or they may be slanting in any direction, as shewn in Figure 6. Rotatory
motion may be imparted to these guides by the friction produced upon them
during the progress of the blank or by any other suitable means; and owing to the
constant variation going on in the surface with which the blank is brought in contact,
excessive heating is obviated and the surfaces may be easily kept cool by water
dripping thereon.
In Fig. 29 an arrangement is shown in which three or four rollers bear simul-
taneously upon the same blank. In this case, the blank is self-guiding, and
consequently the guides shewn in previous arrangements may be dispensed with.
But if pipes are to be rolled out which are smaller than the space that remains clear
when the rollers touch each other, it becomes necessary to co arrange the rollers that
they can gear into each other. The way in which this is done is shown in Fig. 30,
while Fig. 31 shews the position which the rollers occupy towards one another. The
best plan is to let the projections of two rollers that are opposite to one another bear
apon the same circumference, while the two other rollers likewise work opposite to
each other, but within the grooves formed upon the first pair. In this way, every
portion of the blank, while moving forward, is worked upon alternately by two rollers
laid horizontally, and by two set at right angles to the two others.
In the process of oblique rolling, one end of the blank is always finished right off
by constant rotation and repeated drawing-out, before the other end enters the rollers.
To prevent the other end from getting cold, the blank may be placed within a heat-
preserving apparatus fitted in front of the rollers in such a way that while the rolling
process is proceeding, the rollers gradually draw the blank out of the heat-preserving
apparatus. This appliance may be given any suitable form; it may, for example,.
may consist of a simple tube, or of a double tube with intervening asbestos, and the first
heating of the heat preserver may be effected by means of appropriate gases within
the tube or tubes. In most instances, the heat yielded by a number of heated blanks
placed within the heat preserving apparatus is sufficient to give it the desired
temperature, so that the loss of heat that would otherwise ensue prior to the blank's
entering the rollers is considerably decreased. The heat preserving apparatus which
may stand still, or it may rotate together with the pipe, or may have any other motion
imparted to it.
Inasmuch as the rotatory speed of the blanks may be considerably increased in the
case of oblique rolling, it is advisable to fit both in front and behind the rollers an
appliance by which the blank is prevented from performing a jerking movement such
as would naturally ensue directly the blank is bent in any way. This object may
be achieved by fitting in front of and behind the rollers a tube of which the interior
diameter is somewhat greater than the diameter of the blank. Such like guide-tubes,
rings or rollers may consist of one or several pieces, fitted into or upon one another,
or in the place thereof other suitable appliances may be used, which may be stationary
or rotatory or have any suitable motion imparted to them. The flexibility flexure of
a mandrel shaft within a narrow gnide tube or other guiding appliance being limited,
long pipes may be drawn out even with the aid of a thin and more flexible core.
For the oblique-rolling process described in the foregoing, by which solid or hollow
bodies, rotating and at the same time progressing in a straight line, are drawn out or
rolled between rollers-surfaces moving almost in opposite directions, a cross-rolling
process may in some instances be substituted, that is to say a process by which the
blank is caused to rotate between surfaces moving in directions opposite to one another,
without there being at the same time a rectilinear progress of the blank, Having which
has in any suitable manner been brought between the rollers that are continuously or
periodically brought closer to or removed further away from one another the axis of

page_text: the blank, in this process, rotates between these rollers, its axis being thus which remains
parallel to the axes of the rollers; and when the rolling operation has been
accomplished, the rollers may be placed at a greater distance from one another, for
the purpose of removing the blank in its finished form and putting-another in its
place. The arrangement may also be made in such a way that the rollers remain
always at an equal distance from one another and that the blank is placed between
and removed from the rollers by suitable mechanical or hydraulic appliances, either
in a direction parallel to the axes of the rollers or at a right or neute angle to these
axes. If the blank be inserted laterally, the surface of one roller may have a greater
speed imparted to it than the other, and thus the blank is drawn ent in by means of
friction between the rollers, mechanical or other suitable appliances being used for
the same purpose.
In the cross-rolling, the same as in the oblique-rolling process, solid blanks, if their
dimensions be suitably reduced, may be rolled in a hollow or tubular form or partly
solid and partly hollow. In this case the method of making and enlarging holes is
the same as in the case of oblique-rolling. But whereas in oblique-rolling the blank
is gradually and automatically brought nearer to the narrowest point, in cross-rolling
the two rollers are gradually brought nearer to one another by mechanical means, or
else the blank is by similar means brought gradually closer to the spot at which the.
rollers are closest to each other.
Both in oblique and in cross-rolling, the core or mandrel may have an endwise
motion imparted to it in the axis of rotation of the blank, for the purpose of smoothing,
drawing-out or enlarging the hollow produced in the originally solid blank by the
exterior rollers or other appliances acting upon it. In such cases, a forward or
backward motion may be given to the mandrel, or else it may be made to rotate,
oscillate, or vibrate or move in any other suitable manner.
If, in cross-rolling, a blank is to be given a motion parallel to the edges axis of the
rollers, a piston may be used for that purpose, which piston may be actuated by
steam, by water, or by any other suitable mechanical appliances. Similar appliances
may be used in the case of oblique-rolling, when heavy blanks are to be inserted
between, or removed from the rollers, and human power is not found adequate to
achieve this, or too much time may be required for that purpose. The drawing-in of
the blank may likewise be rendered more secure and accurate by means of a stamp,
pusher when the incline of the rollers has been chosen too steep; and by the same
method the movement of the material over the core or mandrel may be accelerated, or
the enlargement of the pipes or tubes facilitated.
When the oblique rolling process is performed with cylindrical, conical or other
rollers, as shown in Figures 1 B, 2, 3, 10, 11, 12, 13, 14, 15, 16, 17 A, 21, 22, the
motor is placed at the side of the ingress of the blank, and the egress is on-the-side
opposite the motor. By this method the length of the finished pipe is rendered
independent of the size of the space between the transmission shaft and the rollers, so
that pipes of very great length may be rolled, and arrangements more efficiently
made for exchanging the cores or mandrels. However, the motor may equally well be
placed at the side of the egress of the blank. In Fig. 23, an arrangement is shewn in
which the working surfaces of face-plate or disk rollers may be given any suitable
form, and the operation takes place in a transverse direction to the axis of the rollers.
In this case, three blanks are worked simultaneously. When face-plates, conic,
convex or concave discs are used, the blank may be introduced at that end of the
rollers or discs which describes a smaller circle, and it may emerge at the larger
circumference (Figures 1A and 17 B), or else the blank may pass over from the larger
circumference or from that part of the roller which describes the larger circle, to the
smaller circumference. In the former case, the rotation of the surface of the blank
increases continuously, in the latter it is gradually reduced.
If two apparatus of this description be placed one behind the other, so that the
blank must pass through both, the speed at which the blank rotates may be gradually
increased in the first and gradually reduced in the second apparatus. An initial

page_text: increase with subsequent reduction of the speed at which the blank rotates may be
obtained even with one set of rollers, if the point at which the rollers are closest to
one another be between the ingress and the egress, as shewn in Figures 12, 17 A, 17 B
and 20. If that speed is to be first reduced and then accelerated, the face-plate
arrangement must be used.
The first process herein described of rolling solid blanks into pipes without the use
of a core or mandrel can be applied without a subsequent smoothing process only in
those cases in which the diameter of the blank is very small or in which the thickness
of the sides of the pipe or tube is to be very great.
The second process of rolling hollow tubes by the aid of a core or mandrel can also
be employed in but a few instances, because it would involve too much expense to
make the hollow according to the method hitherto in use. A real saving of expense
can only be obtained by a combination of the two methods, that is to say by rolling
solid blanks without a core or mandrel, and by rolling hollow or perforated bodies to
pipes or tubes in one or in several operations. For this purpose we first roll the
blanks according the first method, and then, after heating them once more, pass them
through rollers according to the second method, whereby they are made into perfect
pipes or tubes suited for practical uses. The two processes with and without a core
or mandrel may even he carried out in one heat, two or more sets of rollers being
fitted up in succession to, or by the side of, one another; and such sets of rollers may
be identical to or differ from one another in their construction. The rough-rolling
without a core or mandrel and the finishing operation with a core or mandrel may be
combined in one and the same apparatus, as shewn in Figures 17 A and 17 B. In
this case a hollow is first obtained in the blank which was originally solid, while the
second portion of the rollers finishes the operation by the aid of a mandrel, whereby
the side or shell of the pipe is compressed and both the internal and external diameter
enlarged.
By the rough-rolling process which forms the first part of the operation, the inside
of the pipe or tube is not rendered smooth, because some of the detached fibres or
crystals remain projecting upon the surface and are subsequently flattened down by the
motion of the pipe or tube over the core or mandrel. But if, by keeping the inside of the
pipe hermetically sealed against the atmosphere, an oxidation of those particles be pre-
vented, they may in the course of the operation of the mandrel be perfectly welded on to
the sides of the pipe, provided the temperature is such as to admit of such welding, such
temperature being proportionately low in the event of the oxidation of the aforesaid
particles of iron or steel having been guarded against, in the case of iron or steel, at
the early stage of yellow or even of red heat, and defects that may have arisen by
the rolling are entirely remedied by the welding operation alluded to. If the core
or mandrel shuts off the finished piece of pipe or tube sufficiently from the hollow-
space formed by hollow rolling and being either a perfect vacuum or filled with
innocuous gases, the inside may readily be made smooth by welding; and the access
of atmospheric air may equally be prevented by suitable gases being conducted to
the spot. By using any kind of plug and by heating the pipe up to welding heat,
the sides may be made smooth and perfect even if air be admitted.
By means of a suitable selection of dimensions of both the inside and outside of the
pipe or tube and the thickness of the core or mandrel, the extent to which the outside
of the mandrel bears upon or touches the inside of the pipe may be sufficiently
reduced to prevent the mandrel from being heated and worn and the inside of the
pipe from being cooled more than is absolutely necessary. The same object may also
be achieved by means of projections upon the outside of the pipe and by the use of
labricants and of non conductors of heat. The smoothness and rotundity of the
pipe may also be increased by reducing the enlargement of the pipe towards the
egress.
The last finishing touch may be given to the pipe by passing it through two or
more rollers or dies of suitable form, fitted up behind the rolling mill proper, and
acting, either independently or as draw-rollers. Disc-shaped rollers running upon

page_text: supporting axles may be used for finishing the polish of the pipes and may be
arranged in a row, by the side of or above one another, in sets of one, two or more
discs. The polishing rollers or discs which produce their effect either by a rolling or
a sliding friction or partly by one and partly by the other, may be used in connection
with both polishing materials and lubricants, and the polishing operation may also be
performed separately from the rolling process.
Having now particularly described and ascertained the nature of our said Invention
and in what manner the same is to be performed, we declare that what we claim is :
1. The method of, and appliances for, transforming a solid metallic blank into a
pipe or tube, or into a hollow body with one or more solid portions, by the action of
rolling er sliding tools upon the exterior of the blank, thereby inducing causing a
reduction in the diameter of the blank and inducing a rupture along the line of its axis
with a concurrent movement of the metal from the centre to the periphery, as herein
set forth and illustrated.
2. Transforming a solid metallic blank into a seamless tube and smoothing the
inside of such tube by progressively reducing the diameter of the blank, rupturing
the metal along the line of its axis and imparting to the portion of the blank that is
operated upon a progressively varying speed of rotation by means of diagonally noting
or crossway acting rollers or similar devices impinging upon different sides of the
blank, substantially as set forth and illustrated.
3. The method of, and appliances for, rolling seamless metallic tubes the shell of
which is wholly composed of fibres of metal overlaid spirally around the axis thereof,
as herein described and illustrated.
4. 2 Transforming a solid metallic blank into a seamless tube and smoothing the
inside of such tube by and with the aid of as inducing movement of the metal to the
periphery and applying a core or mandrel introduced into such tube and between the
working faces of diagonally or crossway acting rolls, such core or mandrel serving as
an anvil upon which the shell of the tube is progressively compressed by the
impingement of the external rolls thereon, as herein set forth and illustrated.
5. In apparatus for transforming solid metallio ingots or blanks into tubes, two or
more diagonally acting rolls in combination with a mandrel or core interposed
between portions of the working faces of the rolls and so arranged as to preclude the
free access of air to, and the consequent oxidation of the interior of that portion of the
blank which is in process of transformation into a tube, and to serve as an anvil upon
which the shell of the tube is progressively compressed, whereby any cracks or
cavities in its interior surface are closed up or welded, as herein set forth and
illustrated.
6. 3 In apparatus for transforming solid blanks into tubes, two or more diagonally-
acting reducing rolls in combination with two or more adjoining diagonally acting
rolls and a core or mandrel introduced between the working faces of such adjoining
rolls, in the manner and for the purpose herein set forth and illustrated by
Fig. 26 B.
7.4 The method of, and appliances for, e Enlarging the size of a hollow metallic
blank by progressively drawing its shell upon and over the surface of a conoidal
mandrel by means of diagonally acting rolls, the working faces of which impinge
upon different sides of the hollow blank and along portions of their lines of impinge-
ment diverge from each other at an angle that is in a prescribed degree more acute
than the angle formed by the sides of the mandrel with each other, as herein set forth
and illustrated.
&5 In apparatus for enlarging metallic tubes or hollow blanks, or for transforming
solid blanks into tubes and then enlarging them, the combination of a conoidal mandrel
with diagonally acting rolls, so arranged that opposite portions of their working faces,
adjacent to the mandrel, diverge from each other, substantially as and for the purpose
set forth and illustrated.

page_text: 9. The use or employment of diagonally-acting reducing rolls for imparting a
tubular formation to a solid blank passed endwise between their working faces, in
combination with two or more diagonally noting enlarging rolls arranged on different
sides of a conoidal mandrel, and having opposite portions of their working faces
divergent at an angle of prescribed neuteness with the axis of the mandrel, as herein
described and illustrated.
10. The use or employment of two or more diagonally acting rolls, the opposite
portions of the working faces of which converge for a prescribed distance and then
diverge, in combination with a conoidal mandrel interposed between the divergent
portions of the rolls, as herein set forth and illustrated."
H. 6 The method of, and appliances for producing and enlarging tubes from solid
billets or blanks by the successive impingement thereon of convergent and divergent
working faces of rollers, the former reducing the diameter of the blank, the latter
enlarging it by pressing the inchoate tube against the small end and over the base of
a conoidal mandrel; so that the tube is gradually enlarged to the prescribed size
according to the diameter of the mandrel and the angles of divergence of the working
faces of the diagonally-acting enlarging rolls, as herein set forth and illustrated.
12. The use or employment of cores or mandrels in oblique rolling mills, adjustable
in the line of their axis, as herein set forth and illustrated.
13. The method of and appliances for enlarging the external and internal-diameter
of tubes simultaneously by the action of two or more oblique acting or crossway-
acting external rolls and internal cores or mandrels, as heroin set forth and
illustrated.
14. The mode and manner herein described and illustrated of affixing a conoidal
core or mandrel at its thin end to a shaft that extends through the tubular blank and is
fastened to a stationary part of the machine.
15. The mode and manner herein set forth of effecting a twist of fibres in tubes by
diagonally acting rolls.
16. 7 The mode and manner herein set forth of effecting one twist of fibres in tubes
by diagonally-acting rolls and then effecting another twist opposite the first.
17. In apparatus for enlarging the diameter of tubes or developing a tubular
formation from solid blanks and then enlarging such tubular formation, the com
bination of diagonally acting rollers with a conoidal core or mandrel as heroin set
forth and illustrated in figure 17 of the accompanying sheet of drawings.
18.-The use or employment of rolls arranged in such a manner that their bearings
are placed on one side of the working face of each roll, and that their lines of
impingement upon the blank first converge and then diverge, as herein set forth and
illustrated.
10. 8 In the making of seamless metal tubes, the method of, and appliances for,
transforming solid blanks into tubes by holding back the solid central portion of a
suitably heated blank by means of a red blunt mandril, while the blank is being
subjected to the diagonal rolling and drawing action of two or more rolls, as herein
set forth and illustrated.
20. In the making of seamless tubes from solid blanks by passing such blanks in a
suitably heated state between the working faces of diagonally-acting reducing rolls,
the herein described method of holding back the solid central portion of the houted
blank, by means of a centrally-placed rod projecting into the space between the rolls
and thence into the tube in process of formation, and abutting at its free end against
the solid central portion of the blank, but not touching the interior surface of the
tube in process of formation, as herein set forth and illustrated.
21. In diagonally rolling apparatus for imparting a tubular formation to a solid
blank, the combination of two or more diagonally acting rolls, the working faces of

page_text: which converge with a holding back rod, the free end whereof projects into a space
between the working faces of the rolls in position to receive at the proper time the
impact of the central portion of a solid blank which is being reduced forward by the
impingement upon its surface of the diagonally acting rolls, as heroin set forth and
illustrated.
22. The mode and manner herein described and illustrated of working in diagonally
or crossway acting rolling mills the blanks in different positions or places between
the rolls alternately, or two or more blanks simultaneously.
23. The combination of diagonally or crossway acting rollers with pressing or
drawing mechanisms for the purpose of initiating or effecting an endwise or lateral
movement of the blank between the rollers, or for bringing the blank between, or
taking it out of the rollers, in the manner herein set forth and illustrated.
24. 9 The method of, and appliances for enlarging the interior diameter of tubes
with thick shells or sides, by compressing or stretching the shell by the action of
diagonally or crossway working rolls or other rolling or sliding tools upon the outside
of the tube, and thereby inducing an outward movement of the material from the axis
of the tube, as herein set forth and illustrated by Fig. 10.
Dated this 2nd day of May 1887.
J. T. DANN,
32, Canterbury Road, Brixton, S.W.,
Applicants' Agent.

page_text: Date of Application, 3rd Aug., 1886.
Complete Left, 2nd May, 1887.
Complete Accepted, 14th June; 1887
Manuiacture of ripes of
REINHARD MANNESMANN and MAX MANNESMANN, both of Remscheid, in the Empire
of Germany, manufacturers, do hereby declare the nature of this invention to be as
follows:-
This Invention is an improvement upon and further development of the method of
rolling solid or hollow blocks of metal which was communicated by us to Herbert
such
John Haddan and for which Letters Patent were granted to him last year,
Letters Patent being dated January 27th 1885 No. 1167; and it relates to the making
of pipes or tubes out of solid metal by passing the blank once or several times through
to the rollers and, while doing so, imparting to such blank a rotatory motion between
the rollers.
Between two rollers, the axes of which are placed at an angle to one another, a block
of metal a is made to pass, having a rotatory and at the same time a longitudinal motion
imparted to it. In Fig. 1 A the rollers are shewn as being placed side by side to, in
Fig. 1 B as being placed above one another, and in Fig. 2 also they work beside each
other. In all the three arrangements, one roller revolves in a direction opposite to
that of the other. In Fig. 1A, the working takes place between the lateral, and in
Fig. 1 B and 2 between the circumferential surfaces of the rollers. Towards the egress
the distance of the rollers from one another becomes less, so that the piece of metal
performs a spiral motion on emerging from the rollers AA, A'A'. For the purpose of
regulating the motion of the blank we provide lateral guides 6 b, Figs. 1 and 2, or friction
rollers & Fig. 3. The guides may also be longitudinally arranged, as shewn in Fig. 4
and Fig. 5. These guides d d are made to rotate within the guide-bar b. The surface
line of the guides da may be rising towards the egress of the blank, as shewn in Fig. 4,
or towards the ingress thereof, as shewn in Fig. 5, or else they may be slanting in any
direction, as shewn in Fig. 6. The rotatory motion may be imparted to these guides
by the friction produced upon them during the progress of the blank or by any other
suitable means; and owing to the surfaces, with which the blank is brought in contact,
varying constantly, the excessive heating is obviated and the surfaces may be readily.
C

page_text: .
kept cool by water dropping thereupon or by other methods. When the blank.
Fig. 1 to 3 has been sufficiently heated to make it soft enough, or if it be possessed of
a sufficient degree of plasticity in ordinary temperature, and if during the passage
through the rollers a sufficient reduction of dimensions takes place, a transfer of
material from the centre towards the circumference of the blank is effected, and by
external compressions or by displacement of molecules a pipe is formed without the
use of a core. Such would for example be the case if a cast steel billet of 18 inch be
worked and if the spiral threads performed by the blank be not too distant from each
other, so that, when the axis of rotation of the blank forms an angle of six degrees with
the roller, the blank of 12 inch advances 08 inch at every revolution. The dimension
of the hollow formed depends upon several circumstances, to wit-
1st. The proportion between the speed, at which the rotation takes place, and the
progress of the blank. The hole will be largest when there is a certain proportion
between the circular and the rectilinear motion which is determined by the nature of
the material, the temperature, the superficial area of the rollers, as well as their speed,
dimensions and position, the most suitable proportion being in each instance
ascertained by practice. As the proportion varies, the hole becomes less, until it
disappears altogether and the blank remains solid.
2. The position of the blank between the rollers. The more contral the position of
the blank, the larger the hole will be, and conversely, until it disappears altogether
when the blank. occupies a certain lateral position determined by the nature of the
material and by the temperature.
3. The proportion in which the dimensions of the blank are being reduced. The
formation of the hole only commences when a certain reduction takes place, and the
size of the hole and the proportion between its diameter and the external dimension of
the blank increases up to a certain limit, as the size of the blank is growing less.
4. The angle at which the surfaces of the rollers work together.
5. The twist of the fibres, and
6. The configuration of the surface of the rollers. Round or angular projections,
whether parallel or at an angle to the axis of the roller, facilitate the formation of the
hollow, because they tend to increase the superficial area of the roller. The adjust-
ment of the position of the rollers required for the purpose of varying the size of the
hole may be effected while the work is going on or during the intervals by means of
any suitable levers or hydraulic arrangements.
If a solid piece of metal be furnished with bevel ends, as shewn in Fig. 7. i, or if its
thickness be reduced in one or more places, as shown in Fig. 8 i, and such piece of
metal be made to pass through the rollers in the manner set forth in the foregoing, it
becomes tubular in the parts that were originally thick and remains solid in those that
were reduced in size, as shewn in Fig. 7 ii and Fig. 8 ii. Pieces formed like Fig. 7 ii
may be used for railway shafts, as shown in Fig. 9, and those formed like Fig. 8 ii 4
may be cut in several places and used for making grenades and for other purposes. In
the process described, the direction in which the pressure takes place remains constant
while the blank rotates, but the blank may be left unmoved while the direction of the
pressure rotates, or both may rotate, or oscillate or perform any other motion either
jointly or severally. In the same way, the blank and the rollers may work at the 4
same speed or at different speeds, and in such cases the surfaces of the rollers slide
along the surface of the blank. By substituting working surfaces of a different nature
for the roller surfaces, the entire process may be performed by a sliding instead of a.
rotatory motion of the working parts.
In those cases in which the blank was already hollow at the outset, the hole may be 5
enlarged by proper adjustment of the position of the rollers while the process is going
on, and this enlargement may take place although the diameter of the blank itself is
being reduced, as shewn in Fig. 10. By the adjustment referred to, a centrifugal
tendency may be imparted to the material, by which the hole is enlarged. This
tendency may be turned to account for the purpose of enabling a core, tool or other 5
appliance to force its way into the solid metal, such core or other appliance remaining
either motionless or rotating, oscillating or moving in any other way, and being either

page_text: hot or cold or being cooled by water, air or gas, and the most suitable form of such
core or other appliance being determined in accordance with the cone formed between
the solid and the hollow portion of the blank while the progress of the operation is
suspended. By means of the core, a greater amount of smoothness may be given to
the hole produced or enlarged by the operation. A core C is shewn in Fig. 11. By
this core the blank a is prevented from sloping in the direction of its axis and
eventually rotates over it in the form of a pipe. The diameter of the finished pipe
may be equal to, larger or smaller than that of the original blank, but in practice the
adjustment is to be mado in such a way as to add to the tendency of the hole to
enlarge itself. To this end the core or tool is made thicker at one end, as shewn in
Fig. 12.
As the hole grows larger, the centripetal tendency of the core increases, or in other
words, its axis seeks to identify itself with the axis of rotation of the blank, even
though the core had not been originally inserted in the middle of the blank and even
though no hole could be formed without a core. If in the case of a long, solid blank
the core or tool be inserted first from one end and then from the other, in both
instances to half the length of the blank, the two holes formed will meet accurately
in the middle and become concentric, although the tool may originally have been
inserted excentrically; and thus long pipes may be made of which the sides have a
uniform thickness.
66
The working of the core or tool may be assisted and its wear and tear partly
counteracted by the centrifugal tendency of the material, owing to which a hole
spontaneously enlarges itself, even when no core, tool or thorn" is used. In the
arrangement shown in Fig. 13, the pipe, while being rolled, slides over the core d
which is fixed within the bearing fin such a way that it may revolve around its
own axis. The body of the core may be cylindrical or conical, or may be given any
other suitable shape. In the arrangements shewn in Fig. 11 and 12, the core works
by direct pressure only, whilst in Fig. 14 the core e is furnished with friction
rollers which tend to increase both the internal and the external diameter of the pipe.
These friction rollers ought always to be opposite to the rollers A A, and consequently
the core ought not to rotate in this. arrangement. By varying the tendency to the
formation or enlargement of the hole, the pressure with which the material moves or
bears on the core may likewise be varied, and by this method a smooth and even a
polished surface may be given to the interior of the pipe.
•
If the thickness of the side of the pipe at its various stages of manufacture be not
very great in proportion to the internal or external diameter of the pipe, the round of
the core takes its share in the drawing-out, whereas in the case of the sides being thicker
in proportion, the function of the core is to give greater smoothness to the inside of the
pipe and to secure the perfect rotundity both of the inside and the outside of the
finished pipe. But if the side be very thin, the round of the core may tend to stretch
the pipe in the direction of the circumference; and if towards the egress of the pipe,
the distance of the rollers from one another become greater and the core thicker, an
enlargement of the external dimensions of the pipe may be readily achieved, provided
the proportions be appropriately chosen. As the outside diameter increases, the
diameter of the hole must increase in proportion, so that the sectional area of the pipe
at the egress is never greater, but mostly equal to or less than what it is at the
ingress, provided no special arrangements are made for varying the sectional area
in the longitudinal direction of the pipe. In the arrangements Fig. 12 and 15,
the core acts by pressure and in Fig. 16 by tension; and the best plan is to let it
rotate along with the pipe itself. When the core acts by pressure, the pipe in its
finished state moves on to the core; and when the core acts by tension, the pipe slips
automatically away from it. The shape of the core depends essentially on the cone
formed by the inclination of the rollers to one another, on the minimum dimension of
the blank and on the desired thickness of the sides of the pipe, and the best plan is to
find it out by experience for the various dimensions and materials.
In the screw and nut arrangement shewn in Fig. 5, the thickness of the sides of the
pipe may be varied by adjusting the position of the conic core, and it becomes easy in

page_text: such a case to find out the most advantageous position of the core. The correlative
position of the rollers may likewise be adjusted so as to secure the conicity most
suitable for adapting the rollers to any given core. The adjustment of the core in the
direction of its axis and the adjustment of the position of the rollers towards one
another may be effected between the hours of work or even while the work is going
on, by means of any of the well-known mechanical or hydraulic appliances. The
adjustment of the core in the direction of its axis is equally useful for bringing a
thicker portion of the core between the rollers when required.
If the shape shewn in Fig. 12, 14, 15, 16, 17 A and 17 B be given to the rollers, the
blank may be reduced in thickness by the first part of the rollers, provided its initial
thickness was less than the least distance of the rollers from each other; and by the
second part of the rollers, its external dimension may be enlarged again. In this case
the least distance of the rollers froin one another is at a point between the ingress and the
egress of the blank. If the front part of the blank has once been rolled into a hollow or
tubular form, as shewn in Fig. 12, 17 A and 17 B, or if such a tension has been induced
therein as to admit of a core being inserted, as in Fig. 12, pipes with thinner sides
may be made out of the solid blank at one passage through the rollers, either with
reduced, equal or increased external dimensions. In the arrangements Fig. 17 A and
Fig. 17 B the core has no other duty but that of enlarging the hole, the front of the
rollers having already given a tubular form to the blank. In Fig. 12, on the contrary,
the core also aids in forming the hole and in making its surface more smooth and
uniform at the initial stage.
When no core is used and the compression brought to bear on the blank from
without is in itself sufficient to produce the desired hole, the surface of such hole is
rendered smoother and more uniform by two agencies, to wit:-
1. The twist of the fibres-hereinafter called the frictional twist-which is
comparatively slight and is induced by the mere friction of the blank against the
rollers; and
2. The twist of the fibres hereinafter called the heteroclitic twist-which is induced
by projections upon the surface of the rollers and by the grooving or roughing of such
surfaces. The inore the fibres are twisted while the hole is being formed, the more
uniform the surface of the hole must be, for the following reasons:-(a) All blisters,
honeycombs and other deformities in the material are drawn out and their injurious
character is proportionately reduced; (b) These irregularities assume a concentric
order, which neutralises the warping or deflection of the material, in a certain
measure at any rate, when it is being hardened. (c) While the rolling of pipes is
going on, a rupture takes place at the mathematical centre and the hole thus formed is
being enlarged or the blank, while revolving between the rollers, is flattened out to
some extent. Owing to the fibres being constantly twisted or their position toward
each other being otherwise constantly changed, the material is always strained in one
direction or another, and the honeycombs, which under other circumstances would be
superadded to one another, constantly cross each other, and are thereby prevented from
obtaining a notable depth. If the dimensions and proportions be properly chosen in
accordance with experimental practice, pipes may be produced without the use of a
core, by the mere rupture of the interior, and in such a way that the sides of the hole
are comparatively smooth and perfectly free from blisters or honeycombs.
In the event of the material worked upon not being homogeneous, or of
there being irregularities, blisters or pores in billets or rough-rolled pieces,
or of the sides of pipes or tubes of any description not being of uniform thickness
throughout, the frictional or by preference the heteroclitic twist of the fibres may be
turned to account for the purpose of giving the sides of the finished pipes a uniform
thickness in every direction or of compelling an exactly central position of the core
while the rolling process is going on. By means of this twist the fibre of the metal or
other material may be stretched and reduced in thickness during the rolling, such
reduction being in excess of the reduction that takes place in the diameter of the
blank. By this method an amount of strength may be obtained even in the case of
thick pieces, such as could heretofore be obtained only in producing thin pieces by

page_text: rolling; and in thick pieces better stretched and more uniform fibres are obtained, or
else a more delicate grain in the case of granular metals such as steel and iron.
If the blank be heated so rapidly that the interior remains cold and consequently
offers a greater resistance to torsion than the outside, the outside is twisted much
more sharply than the inside, when the material is subjected to a frictional or by
preference to a heteroclitic twist. In this case the fibres do not merely undergo a rope-
like twist around the longitudinal axis of the blank, but the external layers of the
naterial which have the same cross section also undergo a marked displacement
towards the corresponding internal layers. By this means, blisters, honeycombs or
similar irregularities are extended in the direction of the periphery and compressed in
such a way as to assume an approximately concentric order. By applying the break
or reducing the speed at which the thicker portion of the blank rotates, the internal
layers may have a more or less sharp twist given to them in proportion to the external
layers.
In those cases in which the fibres of a blank have been twisted in one direction and
a twist in the opposite direction is imparted to them at the following operation, the
first twist is wholly or partly neutralisod by the second, and the stratification of tho
fibres that results therefrom, will be straight, curvilinear, zigzag or otherwise shaped,
according to circumstances. The second twist may also be effected in one heat with
the first, if two or more sets of rollers be worked in succession, or if different
directions be given to the motion of the various portions of the same set of rollers or
different speeds imparted to them, as will be the case when the blank, after it has been
inserted between the rollers, first rotates slowly, then is made to revolve at a more
rapid rate and eventually has its speed reduced again towards the egress. In Fig. 18,
this stratification of the fibres is illustrated in the shape of a pipe rolled out of a solid
block and having remained solid at one end. The lines are intended to shew how in
such a case the fibres first turn to the right and then to the left.
A second twist of the fibres in a direction opposite to that of the first twist also
takes place if the first rollers cause the piece to rotate at a uniform speed, while the
second rollers cause it to rotate at a gradually reduced rate of speed. Such is the case,
when conic rollers or rollers in the shape of face-plates are used. With some materials
the process may be repeated ad indefinitum, so much so that very complicated
configurations inay be produced thereby.
If in the case of oblique rolling, that is to say when a rotatory and at the same time
rectilinear motion is imparted to the blank, or in the case of cross-rolling-that is to
say if the blank be rolled while revolving between two rollers moving in opposite
directions, but without the blank progressing automatically-projections or notches be
made on the surface of the rollers, to admit of the blank being grasped more firmly
there is an approximate uniformity in the superficial speed of the blank and of the
rollers in the points of contact, and there is less sliding and consequently less wear
and tear of the rollers; it also becomes easier to draw the blank into the rollers. If in
the arrangement Fig. 20 the cone at the back of the rollers be formed very gradually,
a solid blank may be rolled into a pipe of a larger diameter even without using a core;
and if the solid blank be properly gauged, it may even be made into a thicker solid
piece between the rollers. It stands to reason that the two processos may be merged
into one, that is to say the operation of drawing out a thick piece to narrow
dimensions and that of thickening a piece of smaller dimensions. When this is
to be done, the rollers must be so gauged and turned-while leaving the rest of
the apparatus untouched-that towards the egress the material will proceed at a
less rapid rate than in its thinnest part. This is effected by means of sharp
projections made on the surface of the rollers and gearing, as it were, into the
blank, thereby forcing the material back. This process can also be expedited by
artificially reducing the speed at which the blank rotates, in proportion to that of
the movement of the rollers. The projections shewn in Fig. 20. become narrower
towards the egress, and it is best to choose the proportions in such a way that
the projections always bear upon the corrugations upon the surface of the blank,
which are nearer to the egress. By passing once through these rollers, the fibres

page_text: of the blank grow more interwoven and the structure of the metal becomes more
homogeneous. This method of rolling produces practically the same effect as is
achieved in the case of refined steel by repeated welding in packets and by other
kindered operations. The process may also be used for welding iron, for the purpose of
relieving it more completely of scoria by drawing out very thin while twisting its
fibres at the same time. In this case, the result is more favorable than it is with
very thick blanks, and yet the piece worked upon may in the end be rolled solid or
hollow to exactly the required diameter.
Hitherto it has been necessary to make the sides of gas pipes very much thicker
than they need have been to stand the pressure for which they are calculated, lest
there would not remain material enough beneath the threads after the screws had been
cut at the ends. Gas pipes with very thin sides may, by the process herein set forth,
have their sides made thicker at the ends by hydraulic or other suitable mechanical
means, and the screw threads may then be cut at the ends without affecting the safety
of the pipe; by this means, a great saving is also obtained in the weight of the pipes.
The screwed parts may also be fixed at the ends, so that the cutting operation becomes
unnecessary. In that event, the coupling box may be made to run along the entire
length of the pipe; and in the same way as in the case of the ends of the pipes, the
screw threads may be fixed on to the coupling boxes, which themselves may consist of
cuttings of pipes. In Fig. 32 a gas pipe is shewn with screw threads projecting at
the ends at the outside, whilst in Fig. 33 the female screw threads are shewn as
projecting at the inside of the pipe.
If in the case of pipes made without a welded seam according to any of the usual
methods, the cylindrical shape be changed into an oval or other shape by means of a
hydraulic press or by any other mechanical appliance, or if screw or other shafts be
made thereon, the pipes, in yielding to the pressure applied from within or from without,
may be lengthened or shortened or generally have their dimensions altered either
longitudinally or transversely or in both directions. So long as this change does not
go beyond the limit of the strain to which the material may be exposed with safety,
the operation may be repeated. In the case of steam boilers, the motion produced in
the steam pipes by the variation of the steam pressure causes the sediment to break
and loosen itself of its own accord, so that, after it has reached a certain thickness, it
may readily be removed in pieces. In Fig. 19 a pipo is shewn which having been
drawn and twisted out at one end by the variations in the pressure of the steam, has
acquired a tendency to spontaneously break off the sediment that has accumulated.
In all the arrangements constructed according to our Invention, as herein before
described and illustrated in the accompanying sheet of drawings, no more than one
blank is worked upon by the rollers. By a modification in the application of our
Invention, we are enabled to roll two or more blanks between one set of rollers,
especially in those cases in which the dimensions of the blanks are small and the
diameter of the rollers is large. Thus, in Fig. 21, two blanks are shewn as being
rolled simultaneously between the rollers A, A. The best arrangement in cases of
this kind is to place one of the two rollers above the other and the blanks a a by the
side of one another on one and the same table. The friction rollers c c are working
within the lateral guides bb, while the two blanks a a are separated from one another
by the intermediate guide f, to which the form of a friction roller may also be given.
This guide f, however, is not indispensable, and if it be suppressed, the blank will
spontaneously seek to bear upon the friction roller that corresponds to it.
For the friction rollers c c Fig. 21, fast guides bb Fig. 22 may be substituted or
other similar appliances may be used in lieu thereof. In the arrangements shown in
Fig. 21 and 22, two blanks are rolled simultaneously, whilst in Fig. 23, 24 and 25,
three or more blanks may be worked upon at the same time. Even in the arrange-
ments Fig. 21 and 22, three or more pieces might be rolled together, only it would
not be possible to give them all the same diameter, neither would it be possible in the
arrangement shown in Fig. 23. If a set of three rollers be used and the work be
always performed between two rollers, as in Fig. 24 and 25, it will be possible to
obtain two, three, four or six points in which as many as six blanks may be rolled

page_text: simultaneously. The work may also be performed alternately in two or more different
points of the roller system, and while the second blank is being rolled, there is time
enough to remove the first blank that has been rolled at the other point, and to get
ready a new blank in the place thereof. By this means the time during which the
motor does no effective work may be reduced to a minimum and even to nil.
If in oblique rolling the blank is prevented from performing a rotatory or rectili-
near motion corresponding to the motion of the surface of the rollers, it is
made to slide or slip upon the rollers. In that event, those projections
or notches on the surface of the rollers which are not strictly peripheral,
have a tendency to produce a transposition of the surface of the blank, while
projections that move forward and rise towards the egress tend to propel the
material in such a way that the outside of the blank proceeds at a quicker rate than
the inside. Under certain circumstances a hollow body is then formed which may in
certain cases remain closed behind. On the contrary, those projections that work back-
ward and are widened towards the ingress, tend to push the material near the surface
backward, while the inside or the thin end seeks to advance; by this means there
arises an accumulation of the material in the larger section. A tension may also be
produced within the blank, both longitudinally and transversely, by which a drawing-
out or tubular formation of the material may be induced or promoted.
In those cases in which the angle formed by the inclination of the two rollors
towards one another is very large, or in which this angle is suitably chosen, or in
which a sufficient reduction of the dimensions of the blank takes place to cause the
thick end thereof to be seriously impeded in its progress, while the thin end, owing
to its friction against the rollers or the projections upon the surfaces of these is
propelled forward with a great tensile power, a tonsile strain may be induced between
the thick end and the thin end, by which a saving of motive power may be effected
or the rolling process be facilitated, just as in the case of ordinary longitudinal rolling
smaller rollers requiro less motive power than larger ones, because at a less pressure
the fibres are apt to be displaced and drawn out to greater lengths.
To reduce or increase the speed at which the blank moves, in proportion to the
speed of the roller surfaces, provision can be made for applying the break to or
accelerating the motion of the blank, and the same effect can be produced by stopping,
fixing or moving a core working within the blank or by the steep inclination of the
rollers towards oach other or by any other suitable method. By applying the break to
the core, its rotatory motion in regard to the blank may be readily and efficiently varied,
which is a great advantage in the case of a core being furnished with screw-threads,
also because it greatly reduces the wear and tear of the core.
The best way of
applying the break to the blank itself is by increasing its friction against the guides or
the friction rollers. If the core be furnished at its thicker end with projections or
screw-threads placed at an angle to its axis and made steeper towards the rear, and if
its rotatory motion be different from that of the pipe itself, all these circumstances
together may tend to increase the speed at which the pipe moves over the core, and in
the same way the tensile strain induced in the pipe fongitudinally may tend to draw
the pipe out and to make its sides thinner.
If, in rolling pipes out of solid pieces of metal, a core be used of which the
diameter is less than the diameter of the intended hollow, and if the core be brought
sufficiently forward in the direction of the motion of the blank, it is not necessary that
the core or tool should have a sharp point, but its point may be dull or rounded off.
In that case the core, instead of splitting up the material within the blank, rather tends
to produce a compression of the material in the interior, enabling it to more closely
follow the outward tension or, yielding to the pressure of the core, to bulge in an
outward direction where the pressure is less than within. In Fig. 26 a core of this
description is shewn at work. In this case, the blank touches the core only in front,
because the hole that is being produced is greater than the diameter of the core.
In those cases in which the core is prevented from rotating, it need not be round. In
such like cases, the highest points of the core are opposite to the rollers. The core
consists of one or several pieces; it may be furnished with an exchangeable point and

page_text: may be wholly or partly solid or else hollow altogether. In this latter case the hole
may be turned to account for the purpose of introducing liquids or semi-liquids within
the hollow formed in the blank, also for the purpose of keeping the surfaces cool. In
Fig. 27, an oval, hollow and immovable core is shewn, at the top of which there is a
series of lateral holes, through which water, oil or other refrigerants or lubricants may
be allowed to issue. A modification is shewn in a longitudinal section in Fig. 28.
Here, the body of the core consists of two tubes, one working inside the other. The
refrigerating material passes throuuh the intermediate spaces between the two, entering
through the one and oozing out through the other. The inside tube may be continued into
the working part of the core, and the cooling liquid may be introduced either through
the interior or the exterior tube.
When cores are used without cooling appliances, a deformation of the core takes
place while the work is proceeding, especially in those cases in which the diameter of
the blank is small. Such deformation is determined by the variation of the dimen-
sions of the blank as well as by its progress. If both be calculated and adjusted in
such a way that the conicity of the core corresponds to the form that is to be given to
it, the deformation of the core will be less and the wear and tear it undergoes by
friction against the blank more gradual and consequently less perceptible. Inas-
much as, owing to the effect produced by the oxide between the blank and the core,
small particles of the interior of the tube frequently detach themselves and adhere to
the core, the wear and tear of the core may be neutralised altogether. Thus, the core
may oven grow longer and thicker, so that it may be necessary to grind it down from
time to time. If the reduction of the diameter and the rate of speed of the blank be
properly proportioned, while the form given to the core is defective, the core is in
course of time worn down until it reaches the dosired form and the strain upon it is
diminished.
In Fig. 29. an arrangement is shewn in which three or four rollers bear simul-
taneously upon the same blank. In this case the blank is self-guiding, and conso-
quently the guides shewn in previous arrangements may be dispensed with. But if
pipes are to be rolled out which are smaller than the space that reinains clear when the
rollers touch each other, it becomes necessary to so arrange the rollers that they can
gear into cach other. The way in which this is done is shewn in Fig. 30, whilst
Fig. 31 shews the position which the rollers occupy towards one another. The best
plan is to let the projections of two rollers that are opposite to one another, bear upon
the same circumference, while the two other rollers likewise work opposite to each
other, but within the grooves formed upon the first pair. In this way, every portion
of the blank, while moving forward, is worked upon alternately by two rollers laid
horizontally and by two set at a right angle to the two others.
In the process of oblique rolling, one end of the blank is always finished right off
by constant rotation and repeated drawing-out, before the other end enters the rollers.
To prevent the other end from getting cold, the blank may be placed within a heating
apparatus fitted in front of the rollers in such a way that while the rolling process is
proceeding, the rollers gradually draw the blank out of the heating apparatus. This
appliance may be given any suitable form; it may for example consist of a simple
tube or of a double tube with intervening asbestos, and the heating be effected by
means of appropriate gases within the tube or tubes. In most instances, the heat
yielded by a number of blanks placed within the heating apparatus is sufficient to give
it the desired temperature, so that the loss of heat that would otherwise ensue prior
to the blanks entering the rollers is considerably decreased. The heating apparatus
may stand still, or it may rotate together with the pipe, or may have any other motion
imparted to it.
Inasmuch as the rotatory speed of the blanks may be considerably increased in the
case of oblique rolling, it is advisable to fit, both in front and behind the rollers, an
appliance by which the blank is prevented from performing a jerking movement, such
as would naturally ensue directly the blank is bent in any way. The object may be
achieved in fitting in front and behind the rollers a tube of which the interior diameter
is somewhat greater than the diameter of the blank. Such-like guide tubes, rings or

page_text: rollers may consist of one or of several pieces, fitted into or upon one another; or in
the place thereof other suitable appliances may be used which may be stationary or
rotatory or have any suitable motion imparted to them. The flexibility of a core
within a narrow guide tube being limited, long pipes may be drawn out even with the
aid of a thin and more flexible core.
For the oblique rolling process described in the foregoing, by which solid or hollow
bodies, rotating and at the same time progressing. in a straight line, are drawn out
or rolled between rollers moving almost in opposite directions, a cross rolling process
may in some instances be substituted, that is to say a process by which the blank is
caused to rotate between surfaces moving in directions opposite to one another, without
there being at the same time a rectilinear progress of the blank. In this process, the
blank having been placed parallel or oblique or at a right angle between the rollers
that are continuously or periodically brought closer to or removed further away from
one another, rotates between these rollers, its axis being thus either parallel or oblique
or perpendicular to the axes of the rollers; and when the rolling process has been
finished, the rollers may be put at a greater distance from one another, for the purpose
of removing the blank in its finished form and putting another in its place. The
arrangement inay also be made in such a way that the rollers remain always at equal
distance from one another and that the blank is placed between and removed from the
rollers, by suitable mechanical or hydraulic appliances, either in a direction parallel to
the axes of the rollers or at a right or acute angle to these axos.
inserted laterally, one roller has a greater speed imparted to it than the other, and thus
the blank is drawn out by means of friction between the rollers, mechanical or other
suitable appliances being used for that purpose.
If the blank be
In the cross-rolling process, the same as in the oblique-rolling process, solid blanks,
if their dimension be suitably reduced, may be rolled in a hollow or tubular form or
partly solid and partly hollow. In this case the method of making and enlarging holes
is the same as in the case of oblique rolling. But whereas in oblique rolling the
blank is gradually and automatically brought nearer to the narrowest point, in cross
rolling the two rollers are gradually brought nearer to one another by mechanical
means or else the blank is by similar means brought gradually closer to the spot at
which the rollers are closest to each other.
Both in oblique and in cross rolling, the core may have a motion imparted to it in
the axis of rotation of the blank, with a view to the formation of hollow bodies or
In such cases, a
for the purpose of smoothing, drawing-out or enlarging them.
forward or backward motion may be given to the core, or else it may be made to rotate,
oscillate, vibrate or move in any other suitable manner.
If in cross rolling the blank is to be given a motion parallel to the axes of the
rollers, a piston may be used for that purpose, which may be moved by steam, by
water or by any other suitable mechanical appliances. Similar appliances may be used
in the case of oblique rolling, when heavy blanks are to be inserted between or removed
froin the rollers and human power is not found adequate to achieve this or too much
time would be required for that purpose. The drawing-in of the blank may likewise
be rendered more secure and accurate by means of a stamp, when the incline of the
rollers has been chosen too steep; and by the same method the motion of the
material over the core may be accelerated or the enlargement of the pipes be
facilitated.
When the oblique rolling process be performed with cylindrical, conical or other
rollers, as shown in Figures 1 B, 2, 3, 10, 11, 12, 13, 14, 15, 16, 17 A, 20, 21, 22, the
mechanical power is brought to bear upon the ingress of the blank and the egress is
opposite to the spot at which the working of that power takes place. By this method,
the length of the finished pipes is rendered, as it were, independent of the size of the
space between the transmission shaft and the rollers, so that pipes of very great length nay
However,
be rolled and arrangements more efficiently made for exchanging the cores.
the mechanical power may equally well be caused to operate at the egress. In Fig. 23
an arrangement is shewn in which the working surfaces of face-plate rollers may be
given any suitable form and the operation takes place in a transverse direction to the
B

page_text: When
axes of the rollers. In this case, three blanks are worked simultaneously.
face-plates, conic, convex or concave discs are used, the blank may he introduced at
that end of the rollers or discs which describes a smaller circle and it may emerge at
the larger circumference (Fig. 1 A and Fig. 17 B); or else the blank may pass over
from the larger circumference or from the part of the roller that describes the larger
circle, to the smaller circumference. In the former case the rotation of the surface of
the blank increases continuously, in the latter it is gradually reduced.
An initial
If two apparatus of this description be placed one behind the other, so that the
blank must pass through both, the speed at which the blank rotates may be gradually
increased in the first and gradually reduced in the second apparatus.
increase with subsequent reduction of the speed at which the blank rotates may be
obtained even with one set of rollers, if the point at which the rollers are closest to
one another, be between the ingress and egress, as shown in Figures 12, 17 A, 17 B
and 20. If that speed is to be first reduced and then accelerated, the face-plato
arrangement must be used. The foregoing process of rolling solid blanks into pipes
without the use of a core can be applied without a subsequent smoothing process only
in those cases in which the diameter of the blank is very small or in which the thickness
of the sides of the pipe is to be very great.
The second process of rolling hollow tubes by the aid of a core or a tool can also be
employed only in a few instances, because it would involve too much expense to make
the hollow according to the methods hitherto in use. A real saving of expense can
only be obtained by a combination of the two methods, that is to say by rolling solid
blanks without a core, and by rolling hollow or perforated bodies to pipes or tubes in
one or in several operations. For this purpose we first roll the blanks according to
the first method, and then, after heating them once more, pass them through rollers
according to the second method, whereby they are made into perfect pipes or tubes
suitable for practical uses. The two processes, with and without core, may even be
carried out in one heat, two or more sets of rollers being fitted up in succession to, or
by the side of, one another; and such sets of rollers may be identical to or differ from
one another in their construction. The rough-rolling without a core and the finishing
operation with a core may be combined in one and the same apparatus, as shewn in
Fig. 17 A and 17 B. In this case, a hollow is first obtained in the blank which was
originally solid, while the second portion of the rollers finishes the operation by the
aid of a core, whereby the sides of the pipe are made thinner and both the internal and
external diameters enlarged.
By the rough-rolling process which forms the first part of the operation, the inside
of the pipe is not rendered smooth, because some of the detached fibres or crystals remain
projecting upon the surface and are subsequently flattened down by the motion of the pipo
over the core. But if, by keeping the inside of the pipe hermetically sealed against
the atmosphere, an oxidation of those particles be prevented, they may in the course
of the operation of the core, be perfectly welded on to the sides of the pipe, provided
the temperature be such as to admit of such welding, such temperature being propor-
tionately low in the event of the oxidation of the aforesaid particles of iron or steel
having been guarded against, so that the desired effect is obtained, in the case of iron
or steel, at the early stage of yellow or even of red heat, and defects that may have
arisen by the rolling are entirely remedied by the welding operation alluded to. If
the core shuts off the finished piece of pipe sufficiently from the hollow space formed
by hollow rolling and being either a perfect vacuum or filled with innocuous gases,
the inside may readily be made smooth by welding; and the access of atmospheric
air may equally be prevented by suitable gases being conducted to the spot. By using
any kind of flux or by heating the pipe up to welding heat, the sides may be made
smooth and perfect even if air be admitted.
By means of a suitable selection of dimensions of both the inside and outside
of the pipe and the thickness of the core, the extent to which the outside of the core
bears upon the inside of the pipe may be sufficiently reduced to prevent the core from
being heated and worn and the inside of the pipe from being cooled more than is
absolutely necessary. The same object may also be achieved by means of projections

page_text: upon the outside of the pipe and by the use of lubricants and of non-conductors of
heat. The smoothness and rotundity of the pipe may also be increased by reducing
the enlargement of the pipe towards the egress.
The last finishing touch may be given to the pipe by passing it through two or
more rollers or discs of suitable form, fitted up behind the rolling mill proper, and
acting either independently or as draw-rollers. Disc-shaped rollers running upon
supporting axles may be used for finishing the polish of the pipes and may be arranged
in a row, by the side of or above one another, in sets of one, two or more discs. The
polishing rollers or discs which produce their effect either by a rolling or a sliding
friction or partly by one and partly by the other, may be used in connection with both
polishing materials and lubricants, and the polishing operation may also be performed
separately from the rolling process.
Dated this 2nd dovre of Angust 1886
JOSEPH THEODORE DANN,
32, Canterbury Road, Brixton, S.W.,
Agent to the Applicants.

page_text: Manufacture of Pipes or Tubes.
REINHARD MANNESMANN and MAX MANNESMANN, both of Remscheid, in the
Empire of Germany, manufacturers do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This Invention relates to the making of pipes or tubes out of solid or hollow metal
by passing the blank once or several times through diagonally-acting rolls or rollers
and, while doing so, imparting to such blank a rotatory as well as an endwise motion
between the rollers. It is an improvement upon and a further development of the
method of rolling solid or hollow blocks of metal which has been communicated by us
to Herbert John Hadden and for which letters-patent have been granted to him, such
letters-patent being dated January 27th 1885, No. 1167. Our process consists
mainly in working upon the outside of a solid blank by external rolls or rollers in
such a manner that the blank is ruptured along the line of its axis and forced to
assume a tubular shape, either no core or mandrel being used in such cases, or else a
core or mandrel being employed for the purpose of smoothing the inside of the pipe
or tube thus formed, reducing the thickness of its sides or shell, and enlarging its
internal diameter.
An ingot or block of metal a is made to pass between two rolls or rollers, the axes
of which are placed at an angle to one another, in such a way that the block of metal
has thereby a rotatory and at the same time time a longitudinal motion imparted to it.
In Fig. 1 A the rollers are shewn as being placed side by side, in Fig. 1 B as being
placed one above the other, and in Figures 2 and 3 also they work beside each other.
In Fig. 1 A the rolling process is performed between the lateral surfaces of two
disc-rolls A A, which revolve in opposite directions to one another and are placed at
slightly different heights. In Figures 1 B, 2 and 3 the rollers A' A' impinge upon
the blank with their circumferential surfaces, while their axes are inclined in opposite
directions to one another. Thus, a rotatory and at the same time a longitudinal motion,
or in other words a spiral movement, is imparted to the blank in all these arrangements,
by the manner in which the rolls impinge upon it. A conoidal form being given to
the rolls, in such a way that towards the egress of the blank their distance from each
other is reduced, it is obvious that the blank itself, as it passes between the rolls, is
progressively reduced in diameter. For the purpose of keeping the blank in its proper
position during its progress through the rolls and preventing its lateral deviation, we
provide guides or other suitable appliances which will be referred to hereinafter.
When the blank a, Figures 1 to 3, has been sufficiently heated to make it soft
enough, or if it be possessed of a sufficient degree of plasticity in ordinary temperature,
and if, during its progress through the rolls, a sufficient reduction of its dimensions
takes place, a transfer of material from the centre towards the circumference of the

page_text: blank may be effected and by external compressions or by the displacement of
molecules a pipe or tube be formed without the use of a core or mandrel. Such will,
for example, be the case, if a cast-steel billet of 1-8 inch be worked and if the spiral
threads performed by the blank be not too distant from each other, so that, when the
axis of rotation of the blank forms an angle of six degrees with the roller, the blank
of 12 inch advances 8 inch at every rotation. The dimension of the hollow formed
depends upon several circumstances, to wit:-
:-
1st. The proportion between the speed, at which the rotation takes place, and the
progress of the blank. The hole will be largest when there is a certain proportion
between the circular and the rectilinear motion which is determined by the nature of
the material, the temperature, the superficial area of the rollers, as well as their speed,
dimensions and position, the most suitable proportion being in each instance ascertained
by practical experience. As the proportion varies, the hole becomes less, until it
disappears altogether and the blank remains solid.
2. The position of the blank between the rollers. The more central the position of
the blank, the larger the hole will be, and conversely, until it disappears altogether
when the blank occupies a certain lateral position determined by the nature of the
material and by the temperature.
3. The proportion in which the dimensions of the blank are being reduced. The
formation of the hole only commences when a certain reduction takes place, and the
size of the hole and the proportion between its diameter and the external dimension of
the blank increases up to a certain limit, as the size of the blank is growing less.
4. The angle at which the surfaces of the rollers work together.
5. The twist of the fibres, and
6. The configuration of the surface of the rollers. Round or angular projections,
whether parallel to the axis of the roller or at an angle thereto, are apt to facilitate
the formation of the hollow, because they tend to increase the superficial area of the
blank. For the purpose of varying the size of the hollow, the position of the rollers
may be adjusted while the work is going on, or during the intervals, by means of
suitable levers or hydraulic arrangements.
If a solid piece of metal be furnished with bevel ends, as shewn in Figure 7 A, or
if its thickness be reduced in one or more places, as shewn in Figure 8 A, and such
piece of metal be made to pass through the rollers in the manner set forth in the
foregoing, it grows tubular in the parts that were originally thick and remains solid
in those that were reduced in size, as shewn in Figures 7 B and 8 B. Pieces formed
like Figure 7 B may be used for railway shafts, as shewn in Fig. 9, and those formed
like Figure 8 B may be cut in several places and used for making grenades and for
other purposes. In the process described, the direction in which the pressure takes
place remains constant while the blank rotates, but the blank may be left unmoved
while the direction of the pressure rotates, or both may rotate or oscillate or perform
any other movement either jointly or severally. In this way the tubular formation
in a billet may be produced or developed by a mere rotary motion without endwise
movement of the blank between revolving or oscillating rolls or other rolling devices,
but the impingement of the rollers upon the blank, or the reduction in the diameter of
the blank, must be sufficient to effect the rupture of the blank along the line of its
axis and to induce a movement of the material from the centre in an outward direction.
The blank or piece to be rolled may perform any other motion that may be desired
between the rollers, besides the aforesaid rotatory motion; it may, for example, have
an end wise oscillatory movement produced by suitable mechanical appliances. In the
same manner, the surface of the blank and of the rollers may work at the same speed
or at different speeds, and in the latter case the surface of the rollers may slide along
the surface of the blank. By substituting dies or other working surfaces of a different
nature for the roller surfaces, the entire process may be performed by a sliding instead
of a rolling movement of the working parts, but in such cases the blank must also be
impinged upon on opposite sides by such dies or sliding tools, and its diameter be
reduced thereby.
In those cases in which the blank was hollow at the outset, the hole may be enlarged

page_text: by the proper adjustment of the position of the rollers while the process is going on,
and this enlargement may take place although the diameter of the blank itself is
being reduced as shewn in Fig. 10. By the adjustment referred to, the material may
have imparted to it a tendency to assume a tubular formation, whereby the hole is
enlarged. This tendency may be turned to account for the purpose of enabling a core,
mandrel or other appliance to force its way into the solid metal, such appliance
remaining either motionless, or rotating, oscillating, or moving in any other way, and
being either hot or cold, or being cooled by water, air, or gas, and the most suitable
form of such mandrel being determined in accordance with the cone formed between
the solid and the hollow portion within the blank, while the progress of the operatlon
is suspended. By means of the core or mandrel, a greater amount of smoothness
may be given to the hole produced or enlarged by the operation. The mandrel C
shewn in Fig. 11 is prevented from sloping in the direction of its axis, and the blank
rotates over it in the form of a pipe. The diameter of the finished pipe or tube may
be equal to, larger or smaller than that of the original blank, but in practice the
adjustment is to be made in such a way as to add to the tendency of the hole to enlarge
itself. To this end, the core or mandrel is made thicker at one end, as shewn in
Fig. 12. Owing to the tendency of the material to assume a tubular shape, the axis
of the core or mandrel seeks to identify itself with the axis of rotation of the blank,
even though the core had not been originally inserted in the middle of the blank, and
even though no hole could be formed without a core; for the middle of the metal
representing the path of the smallest resistance, the core enters the metal at that path.
If in the case of a long solid blank the core or mandrel be inserted first at one end
and then at the other, and in both instances to the extent of half the length of the
blank, the two holes formed meet accurately in the middle and become concentric,
although the tool may originally have been inserted eccentrically; and by this means
long tubes may be produced of which the sides have a uniform thickness.
The working of the mandrel or tool may be assisted and its wear and tear partly
counteracted by the tendency of the material to assume a tubular formation under the
action of the exterior rolls, by reason of which tendency the hole spontaneously
enlarges itself, even when no core, mandrel or "thorn" is used. In the arrangement
shewn in Fig. 13, the pipe, while being rolled, slides over the core or mandrel & which
may be fitted within the bearing fin such a way than it may, or may not, revolve
around its own axis. The body of the core may be cylindrical or conical, or it may
have any other suitable shape given to it. In the arrangements shown in Figures 11
and 12, the core works by direct pressure only, whilst in Fig. 14 the core e is furnished
with friction rollers r which tend to increase both the internal and the external
diameter of the tube, such friction rollers being especially suited for the rolling of
large-size tubes. These friction rollers require to be always opposite to the rollers A A,
and consequently the core or mandrel ought not to have a rotatory motion in this
arrangement. By varying the tendency to the formanion or enlargement of the hole,
the pressure with which the material moves or bears on the core may likewise be
varied, and by this method a smooth or even polished surface be given to the interior
of the tube.
If the thickness of the sides or shell of the tubo at its various stages of manufacture
be not very great in proportion to the internal or external diameter of the pipe or
tube, the round of the core or mandrel takes its share in the drawing-out, whereas in
the case of the sides or shell being thicker in proportion, the function of the core is to
give greater smoothness to the inside of the tube and to secure the perfect rotundity
both of the inside and the outside of the finished pipe. In the case of the shell being
thinner, the round of the core or mandrel may tend to stretch the pipe or tube in the
direction of the circumference; and if towards the egress of the pipe the distance of
the rollers from one another become greater and the core thicker, an enlargement of
the external dimensions of the pipe may be readily achieved, provided the proportions
be appropriately chosen. As the outside diameter increases, the diameter of the hole
must increase in proportion, so that the sectional area of the pipe or tube at the egress
is never greater, but mostly equal to or less than what it is at the ingress, provided no

page_text: special arrangements are made for varying the sectional area in the longitudinal
direction of the pipe. In the arrangements Figures 12 and 15, the mandrel gives
pressure to the mandrel-shaft, and in Fig. 16 it imparts tension thereto; and the best
plan is to let it rotate along with the pipe itself. When the mandrel acts by pressure,
the pipe or tube in its finished state moves on to its shaft ; and when the core acts by
tension, the pipe slips automatically away from it. The shape of the core or mandrel
depends essentially on the cone formed by the inclination of the rollers to one another,
on the minimum dimension of the blank and on the desired thickness of the pipe, and
the best plan is to find it out by experience for the various dimensions and materials.
In the screw-and-nut arrangement shewn in Fig. 15, the thickness of the sides of
the pipe may be varied by adjusting the position of the conic mandrel, and it becomes
easy in such a case to find out the most advantageous position of the core or mandrel.
The correlative position of the rollers may likewise be adjusted so as to secure the
conicity most suitable for adapting the rollers to any given mandrel. The adjustment
of the position of the rollers towards one another may be effected between the hours
of work or even while the work is going on, by means of any of the well-known
mechanical or hydraulic appliances. The endwise adjustment of the cord in the
direction of its axis is equally useful in any oblique-working tube-rolling mill for
bringing a thicker portion of the core or mandrel between the rollers when required.
If the shape shewn in Figures 12, 14, 15, 16, 17 A and 17 B be given to the rollers,
the blank may be reduced in thickness by the first part of the rollers, provided its
initial thickness exceeded the minimum distance of the rollers from each other; and
by the second part of the rollers, its external dimension may be enlarged again. In
this case, the least distance of the rollers from each other is at a point between the
ingress and the egress of the blank. If the front part of the blank has once been
rolled into a hollow or tubular form, as shown in Figures 12, 17 A and 17 B, or if
such a tension has been induced therein as to admit of a core or mandrel being
inserted, as in Fig. 12, pipes or tubes with thinner sides may be made out of the solid
blank at one passage through the rollers, either with reduced, equal or increased
external dimensions. In the arrangements Figures 17 A and 17 B the core has no
other duty but that of enlarging the hole, the front of the rollers having already given
a tubular form to the blank. In Fig. 12, on the contrary, the core also aids in formning
the hole and in making its surface more smooth and uniform at the initial stage.
When no core or mandrel is used for producing the tubular formation, and tho
compression in the exterior of the blank is in itself sufficient to produce the desired
hole, the surface of such hole is rendered smoother and more uniform by two agencies,
to wit:
1st. The twist of the fibres-hereinafter called the frictional twist-which is
comparatively slight and is induced by the mere friction of the blank against the
rollers; the diameter of each roller standing to that of the blank in a different
proportion at the egress from what it does at the ingress, as shewn in the drawings.;
and
2. The twist of the fibres-hereinafter called the heteroclitic twist-which is induced
by projections upon the surface of the rollers and by the grooving or roughing of such
surfaces. The more the fibres are twisted while or before the hole is being formed,
the more uniform the surface of the hole must be, mainly for the following reasons:-
(a) All blisters, honeycombs and other deformities in the material are drawn out and
their injurious character is proportionately reduced; (b.) These irregularities assume a
concentric order, which neutralises the warping or deflection of the material, in a
certain measure at any rate, when it is being hardened; (c). While the rolling of the
pipes or tubes is going on, a rupture takes place at the mathematical centre, and the
blank, while revolving between the rollers, is flattened out to some extent. Owing to
the fibres being constantly twisted or their position towards each other being otherwise
constantly changed by this flattening, the material is always strained in varying
directions, and the honeycombs, which under other circumstances would be superadded
to one another, constantly cross each other, and are thereby prevented from obtaining
a notable depth. No overstraining of the material is produced, however, if the fibres

page_text: of the blank are overlaid spirally around the axis. If the dimensions and proportions
be properly chosen in accordance with experimental practice, pipes or tubes may be
produced without the use of a core, by the mere rupture of the interior, and in such a
way that the sides of the holo are comparatively smooth and perfectly free from
blisters.
In the event of the material worked upon not being perfectly homogeneous, or of
there being irregularities, blisters or pores in billets or rough-rolled picces, or of the
sides or shell of pipes or tubes of any description not being of uniform thickness
throughout, the frictional, or, by preference the heteroclitic twist of the fibres may be
turned to account for the purpose of giving the sides of the finished pipes a uniform
thickness in every direction, or of compelling an exactly central position of the core
while the rolling process is going on. By means of this twist the fibre of the metal
or other material may be stretched and reduced in thickness during the rolling, such
reduction being in excess of the reduction that takes place in the diameter of the blank.
By this method an amount of strength may be obtained even in the case of thick
pieces, such as could heretofore be obtained only in producing thin pieces by rolling ;
and in thick pieces better stretched and more uniform fibres are obtained, or else a
more delicate grain in the case of granular metals, such as steel and iron.
If the blank be heated so rapidly that the inside thereof remains colder and
consequently offers a greater resistance to torsion than the outside, the outside is
twisted much more sharply than the inside, when the material is subjected to a
frictional or by preference to a heteroclitic twist. In this case the fibres do not merely
undergo a rope-like twist around the longitudinal axis of the blank, but the external
layers of the material which have the same cross section also undergo a marked
displacement towards the corresponding internal layers. By this means, blisters,
honeycombs or similar irregularities are extended in the direction of the periphery and
compressed in such a way as to assume an approximately concentric order. By
applying the break or reducing the speed at which the thicker portion of the blank
rotates, the internal layers may have a more or less sharp twist given to them in
proportion to the external layers.
In those cases in which the fibres of a blank have been twisted in one direction, and
a twist in the opposite direction is imparted to them at the following operation, the
first twist is wholly or partly neutralised by the second, and the stratification of the
fibres that results therefrom will be straight, curvilinear, zigzag or otherwise shaped,
according to circumstances. The second twist may also be effected in one heat with
the first, if two or more sets of rollers be worked in succession, or if different directions
be given to the motion of the various portions of the same set of rollers or different
speeds be imparted to them, as will be the case when the blank, after it has been
inserted between the rollers, first rotates slowly, then is made to revolve at a more
rapid rate and eventually has its speed reduced again towards the egress. In Fig. 18
this stratification of the fibres is illustrated in the shape of a pipe or tube rolled out of
a solid blank and having remained solid at one end. The lines are intended to shew
how in such a case the fibres first turn to the right and then to the left.
A second twist of the fibres in a direction opposite to that of the first twist also
takes place if the first rollers cause the blank to rotate at a uniforın speed, while the
second rollers cause it to rotate at a gradually diminishing rate of speed. Such is the
case when conic rollers, or rollers in the shape of face-plates are used. With some
materials, the process may be repeated ad infinitum, so much so that a very complicated
configuration may be produced thereby.
If in the case of oblique rolling, that is to say when a rotatory and at the same time
rectilinear motion is imparted to the blank, or in the case of cross-rolling-that is to
say when the blank is rolled while revolving between two rollers moving in a
peripheral direction, but without the blank progressing automatically-projections or
notches be made on the surfaces of the rollers to admit of their impinging more
firmly on the blank, there is an approximate uniformity in the superficial speed of
the blank and of the rollers in the points of contact, and there is less sliding and
consequently less wear and tear of the rollers; it also becomes easier to draw the

page_text: blank into the rollers. If in the arrangement Figure 20 the cone at the back of the
rollers be formed very gradually, a solid blank may be rolled into a pipe or tube of
a larger diameter even without the use of a core or mandrel; and if the solid blank
be properly gauged, it may even be made into a thicker solid piece between the rollers.
It stands to reason that the two processes may be merged into one, that is to say
the
operation of drawing out a thick piece to narrow dimensions and that of thickening a
piece of smaller dimensions. When this is to be done, the rollers must be so gauged
and turned while leaving the rest of the apparatus untouched-that towards the
egress the material will proceed at a less rapid rate than in the thinnest part. This
may be effected by means of sharp projections made on the surface of the rollers and
impinging upon, or gearing, as it were, into the blank, thereby forcing the material
back. This process may also be expedited by artificially reducing the speed at which
the blank rotates, in proportion to that of the movement of the rollers. The
projections shewn in Fig. 20 become narrower towards the egress, and it is best to
choose the proportions in such a way that the projections always bear upon the corru-
gations on the surface of the blank which are nearer to the egress. By passing once
through these rollers, the fibres of the blank grow more interwoven and the structure
of the metal becomes more homogeneous. This method of rolling produces practically
the same effect as is achieved in the case of refined steel by repeated welding in
packets and by other kindred operations. The process may also be used for welding
iron, for the purpose of relieving it more completely of scoria by drawing out very
thin while at the same time twisting its fibres. In this case, the result is more
favourable than it is with very thick blanks, and yet the piece worked upon may in
the end be rolled solid or hollow to exactly the required diameter.
Hitherto it has been necessary to make the sides of gas pipes very much thicker
than they need be for the pressure they are intended to stand. The reason of this is
that if the sides were thinner, there would not remain material enough beneath the
threads after the screws have been cut at the ends. Gas pipes with very thin sides
may have these made thicker at the ends by hydraulic or other suitable mechanical
means, and the screw threads may then be cut at the ends without the safety of the
pipe being endangered thereby; a great saving may also be obtained by this method
in the weight of the pipos. The screwed parts may also be affixed to the ends, so
that the cutting operation becomes unnecessary. The coupling box may be made to
run along the entire length of the pipe; and in the same way as in the ends of the
pipes, the screw threads may be fixed on to the coupling boxes, which themselves may
consist of cuttings of pipes. In Fig. 32, a gas pipe is shewn with screw threads
projecting at the ends outside, while in Fig. 33 the female screw threads are shown
as projecting at the inside of the pipe.
If in the case of pipes made without a welded seam, according to the hereinbefore
described or any other suitable method, the cylindrical be changed into an oval or
other shape, by means of a hydraulic press or any other mechanical appliance, or if
screw or other shafts be made thereon, the pipes, in yielding to the pressure applied
from within or from without, may be lengthened or shortened, or generally have their
dimensions altered, either longitudinally, or transversely, or in both directions. So
long as this change does not go beyond the limit of the strain to which the material
may be exposed with safety, the operation may be repeated. In the case of steam
boilers, the motion produced in the steam pipes by the variation of the steam pressure
causes the sediment to break and loosen itself of its own accord, so that, after it has
reached a certain thickness, it may readily be removed in pieces. In Fig. 19 a pipe is
shown which having been drawn and twisted out at one end by the variations in the
pressure of the steam, has acquired a tendency to spontaneously break off the sediment
that has been accumulating.
In all the arrangements constructed according to our Invention, as hereinbefore
described and illustrated in the accompanying sheet of drawings, no more than one
blank is worked upon by the rollers. By a modification in the application of our
Invention, we are enabled to roll two or more blanks between one set of rollers,
especially in those cases in which the dimensions of the blanks are small and the
1

page_text: -
diameter of the rollers is large. Thus, in Fig. 21, two blanks are shewn as being
rolled simultaneously between the rollers A² A³. The best arrangement in cases of
this kind is to place one of the two rollers above the other, and the blanks a a by the
side of one another, on one and the same table. The friction rollers c c are working
within the lateral guides 6 b, while the two blanks a a are separated from one another
by the intermediate guide f, to which the form of a friction roller may also be given.
This guide f, however, is not indispensable, and if it be suppressed, the blank will
spontaneously seck to bear upon the friction rollor corresponding to it.
For the friction rollers c c Fig. 21, fast guides bb Fig. 22 may be substituted, or
other similar appliances may be used in lieu thereof. In the arrangements shewn in
Figures 21 and 22, two blanks are rolled simultaneously, whilst in Figures 23, 24
and 25 three or more blanks may be worked upon at the same time. Even in the
arrangements Figures 21 and 22, three or more pieces might be rolled together, only
it would not be possible to give them all the same diameter, neither would it be
possible in the arrangements shewn in Fig. 23. If a set of three rollers be used, and
the work be always performed between two rollers, as in Figures 24 and 25, it will be
possible to obtain two, three, four or six points, in which as many as six blanks may
be rolled simultaneously. The work may also be performed alternately at two or
more different points of the roller system, and while the second blank is being rolled,
there is time enough to remove the first blank that has been rolled at the other point,
and to get ready a new blank in place thereof. By this means the time during
which the motor does no effective work may be reduced to a minimum, and even
to nil.
If in oblique rolling the blank is prevented from performing a rotatory or rectilinear
motion, corresponding accurately to the motion of the surface of the rollers, it is made
to slide or slip upon the rollers. In that event, those projections or notches on the
surface of the rollers which are not strictly peripheral have a tendency to produce a
transposition of the surface of the blank, while projections that move forward and rise
towards the egress tend to propel the material in such a way that the outside of the
blank proceeds at a quicker rate than the inside. Under certain circumstances, &
hollow body is then formed which may in certain cases remain closed behind. On the
contrary, those projections that work backward and widen towards the ingress, tend
to push the material near the surface backward, while the inside or the thin end seeks
to advance; by this means there arises an accumulation of material in the larger
section. A tension may also be produced within the blank, both longitudinally and
transversely, by which a drawing-out or tubular formation of the material may be
induced or promoted.
In those cases in which the angle formed by the inclination of the two rollers
towards one another is very large, or in which this angle is suitably chosen, or in
which a sufficient reduction of the dimensions of the blank takes place to cause the
thick end thereof to be seriously impeded in its progress, while the thin end, owing to
its friction against the rollers or against the projections upon the surfaces of these, is
propelled forward with a great tensile power, a tensile strain will be induced between
the thick and the thin end by which a saving of motive power may be effected or the
rolling process be facilitated, just as in the case of ordinary longitudinal rolling smaller
rolls require less motive power than large ones, because at a less pressure the fibres
are apt to be displaced and drawn out to greater lengths.
To reduce or increase the speed at which the blank moves, in proportion to the
speed of the roller surfaces, provision can be made for applying the break to, or
accelerating the motion of the blank, and the same effect can be produced by stopping,
fixing, or moving a core or mandrel working in the blank, or by the steep inclination
of the rollers towards each other, or by any other suitable method. By applying the
break to the core or mandrel, its rotatory motion in regard to the blank may be
readily and efficiently varied, which is a great advantage in the case of a core being
furnished with screw threads, also because it greatly reduces the wear and tear of the
core. The best way of applying the break to the blank itself is by increasing its
friction against the guides or the friction rollers. If the core or mandrel be furnished

page_text: at its thicker end with projections or screw-threads placed at an angle to its axis, and
made steeper towards the rear, and if its rotatory motion be different from that of the
pipe or tube itself, all these circumstances together may serve to increase the speed at
which the pipe or tube moves over the core or mandrel, and in the same way the
tensile strain induced in the pipe longitudinally may tend to draw the pipe out and to
make its sides thinner.
If, in rolling pipes out of solid pieces of metal, a core be used of which the diameter
is less than the diameter of the intended hollow, and if the core be brought sufficiently
forward in the direction of the motion of the blank, it is not necessary that the core
or mandrel shall have a sharp point, but its extremity may be dull or rounded off.
In that case the core or mandrel, instead of splitting up the material of the blank,
rather tends to produce a compression of the material in the interior, thereby enabling
it to more clearly follow the outward tension or, yielding to the pressure of the core,
to bulge in an outward direction where the pressure is less than within. In Fig. 26 A,
a core or mandrel of this description is shewn at work. The blank here touches the
mandrel only in front, because the hole that is being produced is greater than the
diameter of the mandrel.
Instead of the tubular formation and the compression of the of the sides or shell of
the inchoate pipe or tube being performed by one set of rolls, two sets of rolls acting
in-succession to one another may be used. Fig. 26 B illustrates an arrangement of
this kind. In this case, two diagonally-acting rollers A A, are used to transform a
solid blank into a tube, and another pair of rollers B B, are employed to receive the
tube formed by the rolls A A, and compress the thickness and weld the interior
surface of such tube, thereby converting the blank D into a finished tube ('.
In those cases in which the core or mandrel is debarred from rotating, it need not
be round. In such like cases, the highest points of the core or mandrel are opposite
to the rollers. The mandrel consists of one or several pieces; it may be furnished
with an exchangeable point, and may be wholly or partly solid, or else hollow
altogether. In this latter case, the hole may be turned to account for the purpose of
introducing liquids, or semi-liquids, in the hollow formed in the blank, also for the.
purpose of keeping the surfaces cool. In Fig. 27, an oval, hollow and immovable
core is shewn, at the top of which is a series of lateral holes, through which water,
oil or other refrigerants or lubricants may be allowed to issue. In Fig. 28, a modifi-
cation is shewn in a longitudinal section. Here, the body of the mandrel consists of
two tubes, one working inside the other. The refrigerating material passes through
the intermediate spaces between the two, entering through one and going out through
the other. The inside tube may be continued into the working part of the core,
and the cooling liquid may be introduced either through the interior or the exterior
tube.
When cores or mandrels are used without cooling appliances, they are subject to
deformation while the work is proceeding, especially in those cases in which the
diameter of the blank is small. Such deformation is determined by the variation of
the dimensions of the blank, as well as by its progress. If both be calculated and
adjusted in such a way that the conicity of the core or mandrel corresponds to the
form that is to be given to it, the deformation of the core will be less, and the wear
and tear it undergoes by friction against the blank more gradual and consequently
less perceptible. Inasmuch as, owing to the effect produced by the oxide between the
blank and the core, small particles of the interior of the tube frequently detach them-
selves and adhere to the core or mandrel, the wear and tear of the mandrel may be
neutralised altogether. Thus, the mandrel may even grow longer and thicker, so
that it may be necessary from time to time to grind it down. If the reduction in the
diameter and the rate of speed of the blank be properly proportioned, while the form
given to the core is defective, the core is, in course of time, worn down until it reaches
the desired form, and the strain upon it is diminished.
For the purpose of regulating the motion of the blank during the progress of the
tubular formation, we provide lateral guides shewn in several of the views such as

page_text: Figures 1, 2, 22 and 25, in which they are marked bb, or frictions rollers c c, as
shewn in Figures 3 and 21. The guides may also be longitudinally arranged,
as shewn in Figures 4 and 5. These guides, marked d d, are made to rotate within
the guide-bar . The guides d d may be fitted so as to rise towards the egress of the
blank, as shewn in Fig. 4, or towards the ingress thereof, as shewn in Figure 5, or
they may be slanting in any direction, as shewn in Figure 6. Rotatory motion may
be imparted to these guides by the friction produced upon them during the progress
of the blank or by any other suitable means; and owing to the constant variation
going on in the surface with which the blank is brought in contact, excessive heating
is obviated and the surfaces may be easily kopt cool by water dripping thereon.
In Fig. 29 an arrangement is shewn in which three or four rollers bear simul-
taneously upon the same blank. In this case, the blank is self-guiding, and
consequently the guides shewn in previous arrangements may be dispensed with.
But if pipes are to be rolled out which are smaller than the space that remains clear
when the rollers touch each other, it becomes necessary to so arrange the rollers that
they can gear into each other. The way in which this is done is shewn in Fig. 30,
while Fig. 31 shews the position which the rollers occupy towards one another. The
best plan is to let the projections of two rollers that are opposite to one another bear
upon the same circumference, while the two other rollers likewise work opposite to
each other, but within the grooves formed upon the first pair. In this way, every
portion of the blank, while moving forward, is worked upon alternately by two rollers
laid horizontally, and by two set at right angles to the two others.
In the process of oblique rolling, one end of the blank is always finished right off
by constant rotation and repeated drawing-out, before the other end onters the rollers.
To prevent the other end from getting cold, the blank may be placed within a heat-
preserving apparatus fitted in front of the rollers in such a way that while the rolling
process is proceeding, the rollers gradually draw the blank out of the heat-preserving
apparatus. This appliance may be given any suitable form; it may, for example,
consist of a simple tube, or of a double tube with intervening asbestos, and the first
heating of the heat-preserver may be effected by means of appropriate gasos within
the tube or tubes. In most instances, the heat yielded by a number of heated blanks
placed within the heat-preserving apparatus is sufficient to give it the desired
temperature, so that the loss of heat that would otherwise ensue prior to the blank's
entering the rollers is considerably decreased. The heat-preserving apparatus may
stand still, or it may rotate together with the pipe, or may have any other motion
imparted to it.
Inasmuch as the rotatory speed of the blanks may be considerably increased in the
case of oblique rolling, it is advisable to fit both in front and behind the rollers an
appliance by which the blank is prevented from performing a jerking movement such
as would naturally ensue directly the blank is bent in any way. This object may
be achieved by fitting in front of and behind the rollers a tube of which the interior
diameter is somewhat greater than the diameter of the blank. Such like guide-tubes,
rings or rollers may consist of one or several pieces, fitted into or upon one another,
or. in the place thereof other suitable appliances may be used, which may be stationary
or rotatory or have any suitable motion imparted to them. The flexibility of a
mandrel shaft within a narrow guide tube or other guiding appliance being limited,
long pipes may be drawn out even with the aid of a thin and more flexible core.
For the oblique-rolling process described in the foregoing, by which solid or hollow
bodies, rotating and at the same time progressing in a straight line, are drawn out or
rolled between rollers moving almost in opposite directions, a cross-rolling process
may in some instances be substituted, that is to say a process by which the blank is
caused to rotate between surfaces moving in directions opposite to one another,
without there being at the same time a rectilinear progress of the blank. Having in
any suitable manner been brought between the rollers that are continuously or
periodically brought closer to or removed further away from one another, the blank,
in this process, rotates between these rollers, its axis being thus parallel to the axes of

page_text: the rollers; and when the rolling operation has been accomplished, the rollers may
be placed at a greater distance from one another, for the purpose of removing the
blank in its finished form and putting another in its place. The arrangement may
also be made in such a way that the rollers remain always at an equal distance from
one another and that the blank is placed between and removed from the rollers by
suitable mechanical or hydraulic appliances, either in a direction parallel to the axes
of the rollers or at a right or acute angle to these axes. If the blank be inserted
laterally, the surface of one roller may have a greater speed imparted to it than the
other, and thus the blank is drawn out by means of friction between the rollers,
mechanical or other suitable appliances being used for the same purpose.
In the cross-rolling, the same as in the oblique-rolling process, solid blanks, if their
dimensions be suitably reduced, may be rolled in a hollow or tubular form or partly
solid and partly hollow. In this case the method of making and enlarging holes is
the same as in the case of oblique-rolling. But whereas in oblique-rolling the blank
is gradually and automatically brought nearer to the narrowest point, in cross-rolling
the two rollers are gradually brought nearer to one another by mechanical means, or
else the blank is by similar means brought gradually closer to the spot at which the
rollers are closest to each other.
Both in oblique and in cross-rolling, the core or mandrel may have an endwise
motion imparted to it in the axis of rotation of the blank, for the purpose of smoothing,
drawing-out or enlarging the hollow produced in the originally solid blank by the
exterior rollers or other appliances acting upon it. In such cases, a forward or
backward motion may be given to the mandrel, or else it may be made to rotate,
oscillate, vibrate or move in any other suitable manner.
If, in cross-rolling, a blank is to be given a motion parallel to the edges of the
rollers, a piston may be used for that purpose, which piston may be actuated by
steam, by water, or by any other suitable mechanical appliances. Similar appliances
may be used in the case of oblique-rolling, when heavy blanks are to be inserted
between, or removed from the rollers, and human power is not found adequate to
achieve this, or too much time may be required for that purpose. The drawing-in of
the blank may likewise be rendered moro secure and accurate by means of a stamp,
when the incline of the rollers has been chosen too steep; and by the same method
the movement of the material over the core or mandrel may be accelerated, or the
enlargement of the pipes or tubes facilitated.
When the oblique-rolling process is performed with cylindrical, conical or other
rollers, as shewn in Figures 1B, 2, 3, 10, 11, 12, 13, 14, 15, 16, 17 A, 21, 22, the
motor is placed at the side of the ingress of the blank, and the egress is on the side
opposite the motor. By this method the length of the finished pipe is rendered
independent of the size of the space between the transmission shaft and the rollers, so
that pipes of very great length may be rolled, and arrangements more efficiently
made for exchanging the cores or mandrels. However, the motor may equally well be
placed at the side of the egress of the blank. In Fig. 23, an arrangement is shown in
which the working surfaces of face-plate rollers may be given any suitable form, and
the operation takes place in a transverse direction to the axis of the rollers. In this
case, three blanks are worked simultaneously. When face-plates, conic, convex or
concave discs are used, the blank may be introduced at that end of the rollers or discs
which describes a smaller circle, and it may emerge at the larger circumference
(Figures 1A and 17 B), or else the blank may pass over from the larger circumference
or from that part of the roller which describes the larger circle, to the smaller
circumference. In the former case, the rotation of the surface of the blank increases
continuously, in the latter it is gradually reduced.
If two apparatus of this description be placed one behind the other, so that the
blank must pass through both, the speed at which the blank rotates may be gradually
increased in the first and gradually reduced in the second apparatus. An initial
increase with subsequent reduction of the speed at which the blank rotates may be
obtained even with one set of rollers, if the point at which the rollers are closest to

page_text: one another be between the ingress and the egress, as shewn in Figures 12, 17 A, 17 B
and 20. If that speed is to be first reduced and then accelerated, the face-plate
arrangement must be used.
The first process herein described of rolling solid blanks into pipes without the use
of a core or mandrel can be applied without a subsequent smoothing process only in
thoso cases in which the diameter of the blank is very small or in which the thickness
of the sides of the pipe or tube is to be very great.
The second process of rolling hollow tubes by the aid of a core or mandrel can also
be employed in but a few instances, because it would involve too much expense to
make the hollow according to the method hitherto in use. A real saving of expense
can only bo obtained by a combination of the two methods, that is to say by rolling
solid blanks without a core or mandrel, and by rolling hollow or perforated bodies to
pipes or tubes in one or in several operations. For this purpose we first roll the
blanks according the first method, and then, after heating them once more, pass them
through rollers according to the second method, whereby they are made into perfect
pipes or tubes suited for practical uses. The two processes with and without a coro
or mandrel may even be carried out in one heat, two or more sets of rollers being
fitted up in succession to, or by the side of, one another; and such sets of rollers may
be identical to or differ from one another in their construction. The rough-rolling
without a core or mandrel and the finishing operation with a core or mandrel may be
combined in one and the same apparatus, as shown in Figures 17 A and 17 B. In
this case a hollow is first obtained in the blank which was originally solid, while the
second portion of the rollers finishes the operation by the aid of a mandrel, whereby
the sido or shell of the pipe is compressed and both the internal and external diameter
enlarged.
By the rough-rolling process which forms the first part of the operation, the inside
of the pipe or tube is not rendered smooth, because some of the detached fibres or
crystals remain projecting upon the surface and are subsequently flattened down by the
motion of the pipe or tube over the core or mandrel. But if, by keeping the inside of the
pipe hermetically sealed against the atmosphere, an oxidation of those particles be pre-
vented, they may in the course of the operation of the mandrel be perfectly welded on to
the sides of the pipe, provided the temperature is such as to admit of such welding, such
temperature being proportionately low in the event of the oxidation of the aforesaid
particles of iron or steel having been guarded against, in the case of iron or steel, at
the early stage of yellow or even of red heat, and defects that may have arison by
the rolling are entirely remedied by the welding operation alluded to.
If the core
or mandrel shuts off the finished piece of pipe or tube sufficiently from the hollow
space formed by hollow rolling and being either a perfect vacuum or filled with
innocuous gases, the inside may readily be made smooth by welding; and the access
of atmospheric air may equally be prevented by suitable gases being conducted to
the spot. By using any kind of plug and by heating the pipe up to welding heat,
the sides may be made smooth and perfect even if air be admitted.
By means of a suitable selection of dimensions of both the inside and outside of the
pipe or tube and the thickness of the core or mandrel, the extent to which the outside.
of the mandrel bears upon or touches the inside of the pipe may be sufficiently
reduced to prevent the mandrel from being heated and worn and the inside of the
pipe from being cooled more than is absolutely necessary. The same object may also
be achieved by means of projections upon the smoothness and rotundity of the
the outside of the pipe and by the use of
lubricants and of non-conductors of
pipe may also be increased by reducing the enlargement of the pipe towards the
egress.
The last finishing touch may be given to the pipe by passing it through two or
more rollers or dies of suitable form, fitted up behind the rolling mill proper, and
acting either independently or as draw-rollers. Disc-shaped rollers running upon
supporting axles may be used for finishing the polish of the pipes and may be
arranged in a row, by the side of or above one another, in sets of one, two or more

page_text: discs. The polishing rollers or discs which produce their effect either by a rolling or
a sliding friction or partly by one and partly by the other, may be used in connection
with both polishing materials and lubricants, and the polishing operation may also be
performed separately from the rolling process.
Having now particularly described and ascertained the nature of our said Invention
and in what manner the same is to be performed, we declare that what we claim is :
1. The method of, and appliances for, transforming a solid metallic blank into a
pipe or tube, or into a hollow body with one or more solid portions, by the action of
rolling or sliding tools upon the exterior of the blank, thereby inducing a reduction
in the diameter of the blank and a rupture along the line of its axis with a concurrent
movement of the metal from the centre to the periphery, as heroin set forth and
illustrated.
2. Transforming a solid metallic blank into a seamless tube and smoothing the
inside of such tube by progressively reducing the diameter of the blank, rupturing
the metal along the line of its axis and imparting to the portion of the blank that is
operated upon a progressively varying speed of rotation by means of diagonally-acting
or crossway-acting rollers or similar devices impinging upon different sides of the
blank, substantially as set forth and illustrated.
3. The method of, and appliances for, rolling seamless metallic tubes the shell of
which is wholly composed of fibres of metal overlaid spirally around the axis thereof,
as herein described and illustrated.
4. Transforming a solid metallic blank into a seamless tube and smoothing the
inside of such tube by and with the aid of a core or mandrel introduced into such
tube and between the working faces of diagonally or crossway acting rolls, such core
or mandrel serving as an anvil upon which the shell of the tube is progressively
compressed by the impingement of the external rolls thereon, as herein set forth
and illustrated.
5. In apparatus for transforming solid metallic ingots or blanks into tubes, two or
more diagonally-acting rolls in combination with a mandrel or core interposed
between portions of the working faces of the rolls and so arranged as to preclude the
free access of air to, and the consequent oxidation of the interior of that portion of the
blank which is in process of transformation into a tube, and to serve as an anvil upon
which the shell of the tube is progressively compressed, whereby any cracks or
cavities in its interior surface are closed up or welded, as herein set forth and
illustrated.
6. In apparatus for transforming solid blanks into tubes, two or more diagonally-
acting reducing rolls in combination with two or more adjoining diagonally acting
rolls and a core or mandrel introduced between the working faces of such adjoining
rolls, in the manner and for the purpose herein set forth and illustrated.
7. The method of, and appliances for, enlarging the size of a hollow metallic blank
by progressively drawing its shell upon and over the surface of a conoidal mandrel by
means of diagonally acting rolls, the working faces of which impinge upon different
sides of the hollow blank and along portions of their lines of impingement diverge
from each other at an angle that is in a prescribed degree more acute than the angle
formed by the sides of the mandrel with each other, as herein set forth and illustrated.
8. In apparatus for enlarging metallic tubes or hollow blanks, or for transforming
solid blanks into tubes and then enlarging them, the combination of a conoidal mandrel
with diagonally acting rolls, so arranged that opposite portions of their working faces,
adjacent to the mandrel, diverge from each other, substantially as and for the purpose
set forth and illustrated.
9. The use or employment of diagonally-acting reducing rolls for imparting a
tubular formation to a solid blank passed endwise between their working faces, in

page_text: combination with two or more diagonally-acting enlarging rolls arranged on different
sides of a conoidal mandrel, and having opposite portions of their working faces
divergent at an angle of prescribed acuteness with the axis of the mandrel, as herein
described and illustrated.
10. The use or employment of two or more diagonally-acting rolls, the opposite
portions of the working faces of which converge for a prescribed distance and then
diverge, in combination with a conoidal mandrel interposed between the divergent
portions of the rolls, as herein set forth and illustrated.
11. The method of, and appliances for producing and enlarging tubes from solid
billets or blanks by the successive impingement thereon of convergent and divergent
working faces of rollers, the former reducing the diameter of the blank, the latter
enlarging it by pressing the inchoate tube against the small end and over the base of
a conoidal mandrel; so that the tube is gradually enlarged to the prescribed size
according to the diameter of the mandrel and the angles of divergence of the working
faces of the diagonally-acting enlarging rolls, as herein set forth and illustrated.
12. The use or employment of cores or mandrels in oblique-rolling mills, adjustable
in the line of their axis, as herein set forth and illustrated."
13. The method of and appliances for enlarging the external and internal diameter
of tubes simultaneously by the action of two or more oblique-acting or crossway-
acting external rolls and internal cores or mandrels, as herein set forth and
illustrated.
14. The mode and manner herein described and illustrated of affixing a conoidal
core or mandrel at its thin end to a shaft that extends through the tubular blank and is
fastened to a stationary part of the machine.
15. The mode and manner herein set forth of effecting a twist of fibres in tubes by
diagonally-acting rolls.
16. The mode and manner herein set forth of effecting one twist of fibres in tubes
by diagonally-acting rolls and then effecting another twist opposite the first.
17. In apparatus for enlarging the diametor of tubes or developing a tubular
formation from solid blanks and then enlarging such tubular formation, the com-
bination of diagonally-acting rollers with a conoidal core or mandrel as herein set
forth and illustrated in figure 17 of the accompanying sheet of drawings.
18. The use or employment of rolls arranged in such a manner that their bearings
are placed on one side of the working face of each roll, and that their lines of
impingement upon the blank first converge and then diverge, as herein set forth and
illustrated.
19. In the making of seamless metal tubes, the method of, and appliances for,"
transforming solid blanks into tubes by holding back the solid central portion of a
suitably heated blank by means of a rod, while the blank is being subjected to the
diagonal rolling and drawing action of two or more rolls, as herein set forth and
illustrated.
20. In the making of seamless tubes from solid blanks by passing such blanks in a
suitably heated state between the working faces of diagonally-acting reducing rolls,
the herein described method of holding back the solid central portion of the heated
blank, by means of a centrally-placed rod projecting into the space between the rolls
and thence into the tube in process of formation, and abutting at its free end against
the solid central portion of the blank, but not touching the interior surface of the
tube in process of formation, as herein set forth and illustrated.
21. In diagonally-rolling apparatus for imparting a tubular formation to a solid
blank, the combination of two or more diagonally-acting rolls, the working faces of
which converge with a holding-back rod, the free end whereof projects into a space
between the working faces of the rolls in position to receive at the proper time the
impact of the central portion of a solid blank which is being reduced forward by the

page_text: impingement upon its surface of the diagonally-acting rolls, as herein set forth and
illustrated.
22. The mode and manner herein described and illustrated of working in diagonally
or crossway acting rolling mills the blanks in different positions or places between
the rolls alternately, or two or more blanks simultaneously.
23. The combination of diagonally or crossway acting rollers with pressing or
drawing mechanisms for the purpose of initiating or effecting an endwise or lateral
movement of the blank between the rollers, or for bringing the blank between, or
taking it out of the rollers, in the manner herein set forth and illustrated.
24. The method of, and appliances for enlarging the interior diameter of tubes with
thick shells or sides, by compressing or stretching the shell by the action of diagonally
or crossway working rolls or other rolling or sliding tools upon the outside of the
tube, and thereby inducing an outward movement of the material from the axis of the
tube, as herein set forth and illustrated.
Dated this 2nd day of May 1887.
J. T. DANN,
32, Canterbury Road, Brixton, S.W.,
Applicants' Agent.