Improved Process and Apparatus for Rolling Sheet Metal.
Year: 1895

page_text: Date of Application. 27th June, 1895
Complete Specification Left, 26th Mar., 1896-Accepted, 27th June, 1896
Improved Process and Apparatus for Rolling Sheet Metal.
A communication from FRITZ MENNE, Engineer, of the Firm of Menne & Cie.,
Sheet Rolling Mills, Weidenau-Sieg, Empire of Germany.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
:-
The present invention relates to improvements in rolling-mills for the production
of thin sheet-inetal of all kinds, and especially for rolling out thick sheet iron into
thinner sheets of greater length, and that by the piece or separate sheet. This has
practically been shown to be impossible in the sheet rolling mills hitherto used, on
account of the elasticity and yielding nature of the several working parts; and for
that reason fine sheets are rolled in packs or bundles, i.e., a considerable number of
them laid one on the top of the other.
If, then, it be desired to roll out separate sheets or pieces, iron bands or strips, or
the like, into thinner metal, and so obtain a uniform product it becomes necessary
to substitute, for the hitherto customary set-screws (which serve to adjust the rolls
in relation to each other) a device which not only serves to enable one to exactly
adjust the rollers, but to maintain these latter, under all circumstances, i.e., of
course in the normal rolling process, in that identical position.
If a metal-sheet be introduced between the rotating rollers, it acts, while being
drawn in by them, as a wedge, tending to force them apart. In consequence of
this pressure, the rolls with their running journals first bind, in their bearings, and
these again transmit the pressure to the set-screws, and the latter throw the strain
on their screwed nuts. In each and all of these parts a certain amount of yielding
takes place, as soon as the article to be rolled enters the rollers. In addition to
all this comes the elasticity of the housing-frame itself, which creates a further
yielding. Consequently, it becomes impossible to maintain the screw-adjusted
rulls rigidly motionless in the adjusted position, once the article to be rolled is
introduced, inasmuch as this continual yielding is always taking place. For this
reason it is impossible to turn out the finest sheets singly with rolling mills of the
existing kind, where the rollers are adjusted by means of set-screws, unless the rolls
have, previously to their working, been so strongly pressed together, by turning the
screws, that the giving or yielding in the frame is as far as possible prevented-;-in-
which case, however, there would still be, when the rolls are running empty, an
enormous expenditure of power, apart from many other evils, such as fractured
rolls, cutting of the brasses.
If, however, instead of the set-screws which resist the pressure tending to force
the rolls apart, water under pressure is employed which, by means of hydraulic
rams, press the rolls together, i.e., a living, active force is substituted for a dead
resistance, it is evident that the yielding in the housing-frames is rendered
inoperative before the rolling process begins. But, in order that there may be no
waste of power when the rolls are running idly, projections formed on the bearings
are pressed together as soon as the hydraulic ram receives the water-pressure. In
this manner the full pressure, intended to be applied, can be turned on, without the
rolls themselves being pressed together. It is now rendered possible to regulate

page_text: beforehand the approximation of the rolls to each other with minute accuracy and
the most reliable exactitude, by means of suitable sheet strips, placed between
these projections.
The same result may also be obtained by the use of wedges which can be
screwed up and regulated, by screws, to any desired degree of fineness of opening
corresponding to the desired thickness (or thinness) of the sheet to be rolled.
This device or arrangement also affords security against any fracture occurring
in the housing frames, inasmuch as the hydraulic pressure employed may always
fall short of the breaking strain of any of the several parts, though greater than
the force required to draw or roll out the sheet to be rolled. Then if, by chance,
it should happen that, through inequality, the material passing through the rolls
should be too thick or too hard, the water would be driven out of the ram-cylinder,
without any fracture occurring, inasmuch as there can be no higher pressure in the
housing frames than that of the head of water and the surface of the bydraulic
piston.
This device is equally applicable to three high as to two-high mills or rolls, and
also in case it is desired to use high pressure rolls for turning out excessively thin
plates, when thicker rolls are needed as support to the others, as will readily be
understood; in this case however the projections on the bearings must be
correspondingly lengthened.
:
This invention may be variously applied in practice, according to the work to be
done thus, the pressure can first be applied to the bearings and then the sheet to
be rolled introduced into the rolls in the well-known manner; or the rolls may be
opened or separated sufficiently far to allow the fore-end of the sheet to be con-
veniently inserted between the rolls, so as to ensure its being correctly lodged, and
then the pressure is turned on so as to grip and roll the sheet as required.
It is evident that a rolling-mill of the kind above described having the hydraulic
piston pressing against the lower roll will yield irregularly to pressure. It is
therefore advantageous to apply a device which will maintain the rollers under
pressure perfectly parallel. To this end it is above all necessary to arrange these
appliances so that, they exert a specific uniform pressure on both the hydraulic-
press pistons, and also, bring about a specific and identical giving or yielding of
the water-pressure acting on the two pistons. To which must also be added that
the rolls in the housing frames must be prevented from all bending or deformation
in one or the other direction, and must heat and wear equally.
The former object, viz., the specific uniform pressure upon the two pistons and a
specific uniform giving or yielding of the same is proportionately obtained by the
power to subject both press-cylinders to the action of the same water-pressure,
which results advantageously from their direct connection with one and the same
hydraulic accumulator maintained at a constant pressure. In each pipe connecting
the press-cylinders with the accumulator is arranged a non return valve, which, as
soon as the rolling-work begins, and the press-pistons are thrust back by the rolls,
cuts off the communication with the accumulator; each press-cylinder, however,
communicates by means of a special connecting-pipe with another cylinder, and the
pistons of these two cylinders are firmly connected with each other and suitably
loaded in any convenient manner. Hence it follows that, if one of the press-pistons
is loaded more heavily than the other and gives, the exactly equal quantity of
water is taken from the other press-cylinder, so that the two press-pistons must
move at exactly the same rate.
The bending of the operative rolls is prevented in a well-known manner by
supporting rolls, which, however, are made, in this invention longer than the
operative rollers. By means of this special arrangement the equal and uniform
cooling of the operative rolls by the supporting rolls is obtained; for the latter are
uniformly warmed along the line of contact with the very much heated working
rollers, by that very contact, while the accelerated radiation by means of the
cooling water on the bearings of the supporting rolls takes place so far away from
the line of contact of the rolls as to leave the condition unchanged on that

page_text: particular line; moreover the working rolls will be entirely uninfluenced by
possible dropping of cooling water from the upper supporting rolls.
In the housing frame, three working rolls may be so journalled as to be capable
of a slight vertical movement within certain limits. The object of this arrange-
ment is in order that, when running idle, the rolls may slide against each other
and mutually keep themselves round and accurate. These working rolls are of
exceptionally hard material and of proportionately small diameter; they are
mounted in bearings which are vertically movable in the frames to the full extent
of the working limit of height, but have only a slight lateral freedom of movement
or play, and nevertheless have no pressure to bear in the vertical direction. The
vertical pressure is transmitted to the supporting rolls, which are extremely thick
and, as already stated, longer than the working rolls. The journals of these two
supporting rollers are carried in axle-boxes which have to bear the whole pressure
and are therefore kept suitably cool. Any water dropping from the upper bearings
of the supporting rollers is intercepted and carried away by suitable protecting
sheets. The axle-boxes of the lower supporting-rolls are each placed in communi-
cation with a press-piston, which are packed and work tightly in press cylinders.
These cylinders are connected by pipes with an accumulator, and in each of these
In front of these non return valves,
connecting pipes is fixed a non return valve.
branch pipes connect with twin cylinders, and in each of which works a piston.
These two pistons are rigidly united by a common cross-head or block and so
loaded that the pressure of the accumulator does not suffice to lift them. The
cross-head may also be loaded by a coiled spring, which ouly comes into operation
A set-screw adjusts
when the joint pistons have been raised a certain distance.
the stroke of these pistons.
The rolling-mill works as follows ;-
The supporting-rolls or, better, the working-rolls are set in motion by any
convenient and appropriate means, while a pump, in continual operation, forces
water into the accumulator. Thereupon all the rolls are set running and the relief
valves are opened.
By previously introducing a calibre-sheet between the working rolls, the height
has already been determined to which the set-screw is to be adjusted.
If, now, a thin metal sheet, lying on the table of the rolling-mill for the purpose
of being rolled, be pushed in between the working-rolls, these latter part very
slightly and simultaneously the hydraulic pistons are slightly depressed. The
effect. of this depression is that the hydraulic pistons seek to drive the water from
the cylinders back into the accumulator, and consequently close the non return
valves, so that all communication between the press cylinders and the accumulator
ceases. Owing to the insertion of the sheet to be rolled out between the working
rolls and the cutting off of the water a most powerful increase of pressure results
in the cylinders, which pressure is transmitted by the connecting pipes to the
regulating cylinders so that during the period of rolling now under consideration
the water pressure in the press-cylinders is influenced by the pistons of the
regulating cylinders. Consequently the specific loading of these pistons determines
the limit of working pressure during the rolling. Inasmuch as, however, these two
pistons are rigidly united they can only move jointly over a common distance ;
consequently also the hydraulic press pistons can only move identically whereby
an absolutely uniform pressure on both ends of the lower supporting rollers results.
Now, if the cross-head of the pistons of the regulating-cylinders has been raised
to a specific height the spring lying loosely thereon comes into contact with the
solid frame so that any further lifting of the cross-head is necessarily attended by
a material increase in the resistance. The stroke of the cross-head and therewith
the maximum distance of the possible separation between the pair of working-rolls
is adjusted and determined by the set screw previously mentioned.
At the back of the rolls the sheet thus rolled thinner passes through a grate
shaped guide on to a table; and at the very moment that the rolled sheet quits
the rolls the regulating-pistons are depressed, so that the hydraulic pistons are

page_text: again forced upwards and press the rollers close together, while any waste water
from deficient packing is at once replaced from the accumulator the water in which
once more opens the relief valves.
The metal sheet is then drawn on the table sufficiently far for its hiuder edge to
be free of a pivoted balance-guide which immediately drops on to the grate piece,
and the sheet is then pushed back between the upper working pair of rolls and
rolled out again.
In a modification of the arrangement of the regulating cylinders the mode of
weighting by means of the cross-head is replaced by hydraulic pressure. For this
purpose, the pistons are firmly united by a frame to which rods are connected and
to which is attached a cylinder; in this latter is a tightly packed piston-rod rigidly
secured to the framing and communicating by means of a connecting pipe for the
water forced by the movement of the cylinder with another cylinder. In this
manner the piston of this latter cylinder is lifted which at a certain point of its rise
comes into contact with and also raises a loose additional weight so that from that
moment a greater, but still constant, pressure acts on the regulating pistons and
consequently on the hydraulic press pistons. The weight of the moving cylinder
and rods can be counteracted by the counterpoise weights; while a safety valve
into the accumulator can be provided so as to guard against fracture of any part
of the appliance by an excessive strain.
Dated this 27th day of June 1895.
BOULT & WADE,
Agents for the Applicant.
proved Frocess and Apparatus for Rolling Sheet Metal.
A communication from FRITZ MENNE, Engineer, of the Firm of Menne & Cie.,
Sheet Rolling Mills, Weidenau-Sieg, Empire of Germany.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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:-
The present invention relates to improvements in rolling-mills for the production
of thin sheet-metal of all kinds, and especially for rolling out thick sheet iron into
thinner sheets of greater length, and that as far as possible by the piece or
separate sheet. This has practically been shown to be impossible in the sheet
rolling mills hitherto used, on account of the elasticity and yielding nature of the
several working parts and of the framing; and for that reason fine sheets are
rolled in packs or bundles, i.e.,, a considerable number of them laid one on the top
of the other.
If it be desired to roll out separate sheets or pieces, iron bands or strips, or the
like, into thinner metal, and so obtain a great extension and a uniform product it
becomes necessary (especially for the thinnest grades) to substitute, for the set-
screws hitherto used in rolling mills (which set screws serve to adjust the rolls in
relation to each other) a device which not only serves to enable one to exactly
adjust the rollers, but to maintain these latter, under all circumstances in the normal
rolling process, in that identical position.
If a metal sheet be introduced between the rotating rollers, it acts, while being
drawn in by them, as a wedge, tending to force them apart. In consequence of
this pressure the journals of the rolls first press against their bearings, and these
again transmit the pressure to the set-screws, and the latter throw the strain on
their nuts. In each and all of these parts a certain amount of yielding takes
place, as soon as the article to be rolled enters the rolls. In addition to all this
comes the elasticity of the housing-frame itself, which creates a further yielding.

page_text: Consequently it becomes impossible to maintain the screw-adjusted
adjusted position, inasmuch as yielding is always taking place during the rolling.
For this reason it is impossible to turn out the finest sheets singly with rolling
mills, where the rolls are adjusted by means of set-screws, unless the rolls be so
strongly pressed together, by turning the screw, that the giving or yielding in the
frames is as far as possible prevented; in which case, however, there would be,
when the rolls are running empty, an enormous expenditure of power, apart from
many other evils, such as fractures of rolls and wearing of brasses.
If, however, instead of the set-screws which resist the pressure tending to force
the rolls apart, water pressure is employed which, by means of hydraulic pistons
presses the rolls together, an active pressure is substituted for a resistance, and it
is evident that the yielding in the housing-frames is rendered inoperative before
the rolling process begins. But, in order that there may be no waste of power
one or other of the
when the rolls are running idle, projections a³ formed on
bearings a (Fig. 1.) are pressed together as soon as the piston receives the water-
pressure. In this manner the full pressure, intended to be applied can be turned
on, without the rolls themselves being pressed together. It is possible to regulate
beforehand the approximation of the rolls to each other, with minute accuracy by
means of suitable sheet metal packing-pieces or liners, placed between these
projections and the parts immediately opposed to them.
The same result may also be obtained by the use of wedges moved by screws.
This arrangement also affords security against any fracture occurring in the
housing frames, inasmuch as the hydraulic pressure employed may always fall
short of the breaking strain of any of the several parts, though greater than the
force required to draw or roll out the sheet to be rolled. Then if, the material
passing through the rolls should be too thick or too hard, the water would be
driven out of the cylinder, without any fracture occurring, inasmuch as there can
be no higher pressure in the housing frames than that corresponding to the head.
of water and to the area of the piston.
This device is equally applicable to three-high as to two-high mills or rolls, and
also in case it is desired to use rolls of small diameter, which produce in a single
operation a very considerable extension, which rolls moreover must be supported
by rolls of a greater diameter; in this case however the projections on the bearings.
must be correspondingly lengthened.
This arrangement may be variously applied in practice, according to the work to.
be done; thus, the pressure can be applied to the bearings and then the sheet to.
be rolled introduced into the rolls in the well-known manner; or the rolls may be.
opened or separated sufficiently far to allow the fore-end of the sheet to be.
conveniently inserted between the rolls, so as to ensure its-being correctly lodged,
and then only the pressure turned on so as to grip and roll the sheet as required.
Such a rolling mill is represented in Figure 1 of the accompanying drawings,
from which it is evident that the pistons P pressing against the lower roll will
yield irregularly to pressure. It is therefore advantageous to apply a device
which will maintain the rolls perfectly parallel during the working. To this end
it is above all necessary to provide such a device as to produce an absolutely
uniform pressure on both the press-pistons, and also, bring about an identical
yielding of the water acting on the two pistons. To which must also be added
that the rolls in the housing frames must be prevented from all bending or
deformation in one or the other direction, and must heat and wear equally.
The former object, viz. the exactly uniform pressure upon the two pistons and
exactly uniform yielding of the same is obtained in the present invention by
placing both press-cylinders under water-pressure, which is preferably effected by
connecting them with an hydraulic accumulator in which a constant pressure is
maintained. In each pipe connecting the press-cylinders with the accumulator is
arranged a check valve, which, as soon as the rolling-work begins, and the press-
pistons are thrust back by the rolls, cuts off the communication with the accumu-
lator; each press-cylinder, however, communicates by means of a special connecting-

page_text: pipe with a pair of cylinders, and the pistons of this pair of cylinders are
connected with each other, and suitably loaded. Hence it follows that, if one of
the press-pistons is loaded more heavily than the other and gives, the exactly
equal quantity of water is taken from the other press-cylinder so that the two
press-pistons are each arranged to move through exactly the same distance.
It is not necessary that the said pair of pistons should be rigidly connected to
each other, they need only be controlled in such a manner that when one is caused
to move it either permits or causes the other to move similarly and simultaneously;
for instance a weight may be supported by both, and then if one of them raises
the weight the other will follow the weight, inasmuch as both are under pressure
during the rolling. It is also advisable to provide arrangements for avoiding
drawbacks produced by the water containing a certain amount of air. It has
been found that air is always pumped into the press cylinder together with water
and it is difficult to get rid of that air. This air gathers at the packing and under
the piston and gives a certain elasticity to the water. To get rid of this elasticity
is also an object of the present invention. This is effected by rigidly connecting
the press piston proper with a smaller one and by applying water pressure to the
Jatter in the opposite direction, so that the press piston proper has to overcome a
certain resistance before it presses the rolls together. The movement of the press
piston proper towards the rolls is limited by a nut, which is placed on a screw
threaded continuation of the rod, connecting the pistons, which rod is preferably
led through the smaller piston.
The bending of the operative rolls is prevented in a well-known manner by
supporting rolls, which, however, are made, in this invention, longer than the
operative rolls. By means of this special arrangement the equal and uniform
cooling of the operating rolls by the supporting rolls is obtained; for the latter
are uniformly warmed along the line of contact with the very much heated
working-rollers, by that very contact, while the cooling, accelerated by means of
the cooling water on the bearings of the supporting rolls, takes place so far away
from the line of contact of the rolls as to leave the condition unchanged on that
particular line; moreover by this arrangement the working rolls will be entirely
uninfluenced by possible dropping of cooling water from the upper supporting
rolls.
An improved rolling-mill of this kind is illustrated in the accompanying
drawings,
Figure 2 is a front view, partly in section,
Figure 3 is a cross section on a plane just within one of the housing frames;
Figure 4 a cross section through the hydraulic regulator on an enlarged scale;
Figure 5 is a modification of the latter
Figures 6 and 7 show the press pistons, which prevent the bad effects of the
presence of air in the water.
Figs. 8 and 9 are views, similar to Figs. 6 and 7, of modified constructions of the
press pistons.
In the housing frame A three working rolls bare so journalled as to be capable
of a slight vertical movement within certain limits. The object of this arrange-
ment is that, when running idle, the rolls may slide against each other and
mutually keep themselves round and clean. These working rolls are of
exceptionally hard material and of comparatively small diameter; they are
mounted in bearings c which are vertically movable in the frames to the full extent
of the working limit of height, and have to stand only a slight lateral pressure,
but no pressure in the vertical direction. The vertical pressure is transmitted to
the supporting rolls a, which are extremely thick and, as already stated longer
than the working rolls b. The journals e of these two supporting rollers are
placed in brasses d which have to bear the whole vertical pressure and are there-
fore suitably cooled. Any water. dropping from the bearings of the supporting
rollers is intercepted and carried away by suitable protecting-sheets f (Fig. 2).
The brasses of the lower supporting rolls are each connected with a press-piston P

page_text: and P respectively, which are packed and guided in press cylinders QQ. These
cylinders are connected by pipes q and q with an accumulator R, and in each of
these connecting pipes is fixed a non-return check-valve vand v¹. In front of these
check-valves, branch pipes r and connect the pipes q g' with the cylinders ✗
and Y, in each of which fits a piston x and y. These two pistons are rigidly
united by a common cross-head or block and so loaded that the pressure of the
accumulator R does not suffice to lift them (Figure 4). The cross-head h may
also be loaded by a springs which only comes into operation when the pistons
and y have been raised a certain distance. A set-screw S may limit the stroke of
these pistons.
The rolling-mill works as follows:-
The supporting rolls, or, better, the working-rolls are set in rotary motion in
any convenient manner while a pump continuously working, forces water into the
accumulator R. Thereupon all the rolls are set running against each other and
the non-return valves v v¹ are opened.
By previously introducing a calibre-sheet between the working rolls, the height
is determined to which the set-screw S is to be adjusted.
If, now, a thin metal sheet, lying on the table T of the rolling-mill he pushed
in between the working-rolls b, these latter part and simultaneously the hydraulic
pistons P P are pressed downwards. The pistons seek to drive the water from the
cylinders QQ back into the accumulator through q q', and consequently close the
check valves so that all communication between the press cylinders QQ and
the accumulator R ceases. Owing to the insertion of the sheet to be rolled out
between the working rolls and the cutting off of the water a most powerful
increase of pressure results in the cylinders Q Q', which pressure is transmitted
through the connecting pipes to the cylinders X Y so that during the period
of rolling proper the water pressure in the cylinders Q Q' is influenced by the
pistons y. Consequently the specific loading of these pistons determines the
limit of pressure during the rolling.
+
There are therefore two different pressures at work in the housing frame-the
pressure from the accumulator, which presses the rolls against each other when
they run idle, and the resistance-pressure, produced by the specific load on the
pistons y, which pressure does the rolling work. Such arrangement secures an
insignificant pressure when the rolls run idle, and a very high working-pressure
during the rolling of material.
However, inasmuch as these two pistons y are rigidly united they can only
move jointly over a common distance; consequently also the press pistons P Pi
can only move identically, whereby results an absolutely uniform pressure on the
lower supporting rollers.
Now, if the cross-head has been raised to a certain height the spring lying
loosely thereon strikes the frame Z so that any further lifting of the cross-head h
is necessarily attended by an increase of pressure. The stroke of the cross-head h
and therefore the maximum distance of the possible separation between the pair
of working-rolls can be determined by the set screw S.
At the back of the rolls the rolled sheet-metal passes along a grated guide T¹
or grid on to a table T'; and at the very moment that the rolled sheet quits the
rolls the pistons xy are depressed, so that the pistons P P again press the rolls
together, while any water wasted through deficient packing is at once replaced
from the accumulator R, the water in which once more opens the valves vv.
The metal sheet is then drawn on the table T sufficiently far for its hinder
edge to be free of a lever U of grated form pivotted at u and provided with
fingers entering between the bars of the grate T. This lever which had been
raised by the passage of the sheet along the grate T¹ drops normally into the
position shown in full lines in Fig. 3, so that when the workmen moves the sheet
reversely, it is guided between the upper working rolls b and rolled again.
Fig. 5 shows a modification of the arrangement shown in Fig. 4 in so far as the
mode of weighting by means of the cross-head hand the springs is replaced by

page_text: hydraulic pressure. For this purpose, the pistons & y are firmly united by a
frame h. To this frame are connected rods H carrying a cylinder m; in this
latter is a tightly packed piston-rod secured to the framing Z which rod leads, by
means of a connecting pipe m¹ the water forced out by the movement of m into a
cylinder N. The piston n of the cylinder N is lifted and at a certain point of
its rise comes into contact with and also raises a loosely guided weight g so that
from that moment a greater but still constant pressure acts on the pistons ry
and consequently on the press pistons P P¹ such as were shown in preceding
figures. The weight of the cylinder m and rods h can be counteracted by balance
weights m²; while a safety valve may be provided in the pipe leading from the
pistons P P of Fig. 2 for instance, to the pistons y so as to guard against
fracture by any excessive stress.
Figures 6 and 7 show modified forms of the press cylinders, which prevent the
influence of elasticity of the air contained in the water.
In Figure 6 two pressure pistons P and P° are in separate cylinders Q and are
rigidly connected by a rod. A leather ring or the like is used for packing the
rod connecting the pistons. If the smaller piston is exposed to higher pressure,
then the water in the larger cylinder Q is already in a state of strong compression
before the piston P moves. This compression reduces the air enclosed in water
to such a small volume, that this air can have no influence. As only the excess
of pressure of the piston P is noticeable on the rolls, the idle running of rolls,
when they are not under pressure, will not be influenced. The connecting rod is
easy to pack, as the two press cylinders are pressed against each other.
Both the press pistons P. and P° may also be arranged in one cylinder, and in
spite of that be pressed in different directions, as shown in Figure 7. In this
arrangement the two pistons would, however, stand under the same specific
pressure, whereby the resistance of the smaller pressure piston P° would be less
variable, than in the arrangement shown in Figure 6. But the second arrangement
has the advantage of not necessitating any packing of the rod connecting the
pistons.
It is advantageous to limit the upward movement of the two pistons, and this
may be effected in different ways. lu the drawings the limiting shown to be
effected, for example, by a nut E, which is placed on a continuation of the rod
connecting the two pistons and passing through the smaller one. This nut E is
pressed, in the upward movement of the piston, against a bridge C. Thereby the
nut E not only limits the amount of movement of the piston towards the rolls, but
.does not interfere at all with its backward movement. It can be easily seen, that
the continuation has to stand only the excess of pressure on the larger piston,
and is not affected by the pressure of the rolls. The whole pressure is supported
only by the pressure piston, unlike in the ordinary rolling mills with screws, where
the screw has to stand the full pressure.
By this arrangement of a hydraulic press cylinder an exact working by water
pressure is effected, which is an essential condition to good rolling-work. Besides
the packing rings are already pressed fast against the sides of the press cylinders
before the proper working pressure (which arises through the rolling) begins, so
that the packing is always good.
The regulation of the movement of the pistons P in case it be not uniform, may be
effected by strongly connecting them with pistons Ps. The pistons P' (Fig. 8) have
water on both sides, which water is forced out by their movement. This water I
which stands over the pistons of each cylinder, communicates with water II which
is under the piston of each corresponding other cylinder. If the pistons P' have
the same area, then the movement of one piston will produce an increase of
pressure on the other piston, which then makes a similar movement.
In this way
the before-mentioned regulating pistonsa y can be connected to each other. In
this case also a screw may limit, as in Figure 6, the forward movement of P. As
an alternative the modification shown in Figure 9 can be used. Of course, the
piston at I must then have a smaller area, by the cross-section of piston rod in

page_text: Figure 9, in order that the volumes I and II may remain equal. The cylinders c
and c are secured to each other at g.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is :-
| 1. A process for rolling sheets of metal, characterized by the application of
hydraulic pressure to the rolls, for the purpose of pressing them continuously
together, the rolls themselves being prevented from coming into too close proximity
by projections formed on their bearings, while the thickness of the metallic sheets
when rolled is regulated by special pieces of thin sheet metal or wedges placed
between the said projections substantially as and for the purpose described.
2. In rolling inills the combination with hydraulic pressure pistons of pipe-
connections 9 9 accumulator R check valves and press-pistons such as y
the latter rigidly connected to each other substantially as aud for the purpose
described.
3. In rolling mills the combination with hydraulic pressure-pistons of pipe
connections q' accumulator R check valves vol and pressure pistons such
asy the latter working on a common resistance substantially as and for the
purpose described.
4. In rolling mills the combination with hydraulic pressure pistons and an
accumulator, of pressure pistons such as x and y the latter being either rigidly
connected to each other or arranged to work on the same resistance substantially as
and for the purpose described.
5. In rolling mills the combination with hydraulic pressure pistons and 80
accumulator, of pressure pistons such as x and y and a springs substantially as
and for the purpose described.
6. In rolling mills the combination with hydraulic pressure pistons and an
accumulator, of pressure pistons such as x and y hydraulically loaded, substantially
as and for the purpose described.
7. In rolling mills with accumulator and pressure pistons such as x and y the
arrangement for loading these pistons by springs such as s or by an hydraulic
arrangement such as N n which acts on a free load such as g substantially as and
for the purpose described.
8. In rolling mills the arrangement of supporting rolls which are longer than
the operating ones substantially as described.
9. In rolling mills the arrangement of tilting lever such as U substantially as
and for the purpose described.
10. In rolling mills the arrangement of a grated tilting lever such as U
engaging with a grate shaped table such as T' substantially as and for the purpose
described.
11. In rolling mills the arrangement of press-cylinders with two or more pistons
of unequal diameter and acting in opposite directions substantially as and for the
purpose described.
12. In rolling mills the arrangement of regulating pistons secured to pressure
pistons such as P which regulating pistons have water on both sides, the space over
one piston being in communication with the space under the other, and the reverse
substantially as and for the purpose described.
13. The combination and arrangement of parts constituting the complete rolling
mill substantially as and for the purpose described and illustrated in the accom-
panying drawings.
Dated thin 26th day of March 1906
BOULT & WADE,
Agents for the Applicant.