Improvements in or appertaining to the Manufacture of Steel, Copper, or other Metallic Tubes, and in the Apparatus employed in the said Manufacture.
Year: 1897

page_text: Date of Application. 6th Aug., 1897
Complete Specification Left, 8th Oct.. 1897-Accepted, 6th Aug..
1898
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to the Manufacture of Steel, Copper,
or other Metallic Tubes, and in the Apparatus employed in the
said Manufacture.
I, THOMAS BUDWORTHI SHARP, of County Chambers, Martineau Street, Birming-
ham, Engineer, do hereby declare the nature of this invention to be as follows:-
For many useful purposes as for instance in connection with cycle and motor
car frames boiler tubes et cetera it is desirable to use tubes with ends which are
thicker than the main body of the said tubes. To meet these demands, tubes have
teen (but only to a limited extent) so produced either by an elaborate system of
tube drawing or by "jumping up" by hydraulic pressure or otherwise. Such
tubes however have not come into general use owing to the costly and uncertain
method of manufacture hitherto employed.
Now, my invention has for its object the production (by readier, cheaper and
better methods than have hitherto been employed) of such thick ended tubes and I
do so thus: I take a piece of tube-and preferably an annealed piece-which is
not necessarily any thicker at the ends, than it ultimately will be, after I have
dealt with it but-it may be considerably shorter than it ultimately will be:
this tube I place on a hard mandrel preferably, so as to closely fit it: this mandrel
is preferably of hard steel preferably round and preferably of uniform diameter or
nearly so then, the mandrel together with the tube on it is caused to revolve:
outside the tube, I now place a casing containing a number of little hard steel
balls: this casing which with its little balls may be said to somewhat resemble the
ball bearing arrangement of a modern bicycle is supplied with a means of lateral
adjustment so that the balls may be made to press down upon the tube and so
squeeze it and thin it down and lengthen it by reason of the pressure between the
said balls and the said mandrel on which the said tube is internally supported.
If now while the tube is being revolved I merely close in my balls--I produce a
tube with a groove around it but if in addition to closing in my balls I give to them
a reciprocating motion up and down the middle portion of the tube they are
acting on it is quite clear that the middle portion of the said tube so acted on will
become thinned down and I will then have a tube of uniform or nearly uniform
diameter inside but with a partially reduced external diameter; the length of
such reduction of such external diameter being commensurate with the longi-
tudinal traverse of my balls. I have spoken of a reciprocating action of my reduc-
ing apparatus but I may where I deem it advisable perform the operation by a
single traverse of my said reducing apparatus. Instead of balls I may if I like
use such equivalents as revolving discs, revolving rollers &c. or I may use rounded

page_text: projections which do not revolve inside the casing but which produce a similar
thinning and lengthening effect (by means of a rubbing action,) to that produced
by a rolling action. I may also if I like cause the revolving rollers, just referred
to, to act either by a revolving rolling action after the manner of the balls we
have been speaking of, or they may revolve on fixed pivots after the manner of a
road carriage wheel or their axes may revolve with them and in suitable bearings
after the manner of a railway carriage wheel. Though I prefer the action of the
balls and of as many as I can get in-yet-the points of pressure-whatever they
be may be reduced to any desired degree say to three or even one-but-when
I do this the tube grows in diameter as well as length. To get over this I use a
tubular retainer which slides along the tube at the same time as the thinning
point or points.
Sometimes I keep the mandrel stationary and revolve the thinning apparatus
only or revolve both.
Now, I have spoken of my improved tubes as being parallel inside and of a
greater external diameter at their ends than in their middles but I may if I like
so reduce the ends (by any suitable means--say, by a Ryder forger-) that the
external diameter shall be uniform throughout or I may reduce one or both ends
so that it or they shall be of less external diameter than the body of the tube.
The advantages of a thickened ended boiler tube are too well known, but, not
so, the advantages of thickened ended tubes for cycle frames.
Let us examine this matter. Take a tube 2'0" long × 1/32 thick. Firstly;
look at the weight question.-By the old brazing method the ends are softened
and this with the necessary filing so reduces their strength that they are only (in
the weakest part) equivalent to an uninjured hard tube 1/4" thick-but-we are
carrying a tube " thick through we see that an uninjured tube 1/4" thick
would do thus we are carrying double weight as far as the tubes are concerned.
Secondly; look at the cost question. Instead of buying two feet of tubing 32"
thick we buy one foot of tubing 3/4" thick. This I operate on till it has become
two feet long leaving 21" at each end, unreduced in thickness; in the middle I
then have for a length of 17" a thickness of hard and not only of uninjured but
actually of strengthened tubing rather over 1/4" thick. I say "strengthened tub-
ing" because my process renders the metal more homogeneous and so stronger.
But one foot of tubing 3/4" thick costs less than one half the cost of two feet of
tubing thick so we save over 50% in the cost of the tubing; but-say-my
operation absorbs half the saving (and it does not) we still save 25% Thirdly;
look at the question of strength. My tube is 3/4" thick at the ends and therefore
more than 50% stronger than a tube " thick and also as my tube is rather
over thick in the middle and hard and strong into the bargain and as we have
shewn that, under the old plan, 1/4" thick is ample, for, they use a tube 1/2" thick,
which, they weaken down till it is no stronger than a tube 4" thick we see
clearly that we also gain considerably in strength.
#
#
61
In working out these figures let it be remembered that though I thin and
lengthen my tube I cut away nothing, in fact its weight is unaltered and let it
also be remembered that one foot of tubing " thick is 25% lighter than two feet
of tubing" thick.
G
Thus we can sum up all these benefits in the following words: -
"While we get a stronger tube (and consequently a stronger and better frame)
we simultaneously save 25%, in weight and 25% in money, as far as the tubing is
concerned."
.
T
1007

page_text: Improvements in or appertaining to the Manufacture of Steel, Copper,
or other Metallic Tubes, and in the Apparatus employed in the
said Manufacture.
I, THOMAS BUDWORTH SHARP, of County Chambers, Martineau Street, Birming-
ham, in the County of Warwick, Engineer, do hereby declare the nature of my
said invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
My invention has for its object improvements in or appertaining to the manu-
facture of steel, copper or other metal tubes, and in the apparatus employed in the
said manufacture and is intended to produce metal tubes of variable thickness in
a practically finished condition and ready for working into such purposes as cycle
motor car and other frames as well as for boiler tubes and many other purposes
in a readier, cheaper and better manner than has hitherto been employed. I am
quite aware that to a limited extent tubes thickened at the ends have been produced
by jumping up" but such methods have been costly.
In order that my invention may be clearly understood and more easily carried
into practical effect I have appended hereunto two sheets of drawings illustrating
examples of my apparatus and the mode of manufacture and its application, which
will enable others to apply the invention to the various cases met with in practice.
Figure 1 is a sectional elevation of one of my casings or reducing boxes A ready
for placing over the tube and mandril before the operation of reduction is com-
menced.
Figure 2 is an elevation of the left hand end of the casing or reducing box A.
Figure 3 is an elevation of the right hand end of the reducing box A.
Figure 4 is a part section and part elevation of a tube T which has been reduced
according to my invention and from which the reducing box. A has been removed
but the tube is still on the mandril M. From this form it will be seen that the
tube is held tightly upon the mandril and is prevented from turning except with
the mandril by the set screw which is mounted in the holder K. This holder
may be permanently fixed upon any part of the mandril M. There are many
other ways of holding the tube from turning upon the mandril such for in-
stance as a notch or notches in the end of the tube taking into a projection on the
mandril or by a set screw run through the tube, or the tube may be allowed to bind
itself by friction.
Figure 5 is a front elevation of a modified form of my apparatus for reducing
the centre portion of tubes.
Figure 6 is a side sectional elevation of Figure 5.
Figure 7 is a sectional plan view of Figure 5 taken on the line -y.
The casing or reducing box A has an open end with a screw thread a' into which
the adjusting end E screws with its corresponding screw thread by means of
the nut e solid with the end E which also is formed with a facing piece at its
inner end for the purpose of operating truly against the sliding cone C the oppo-
site cone C being in the example shown stationary at the left end of the box as
shown upon the drawing. It will be seen that the cone C is first placed in the
box which is then threaded over the tube T on the mandril when the balls Bare
put into position. The back cone is then placed in position and the end E
adjusted so as to bring the desired pressure upon the balls B which is due to the
two inclined surfaces 2 and 3 of the cones which are designed in this particular
manner so as to best operate upon the tube to be reduced. The mandril and tube
is passed through the openings H in each end of the box. Soap & water or other
lubricant may be conveyed to the box by the pipe P as required.

page_text: г
The mandril M carrying its tube T and reducing box A is now placed in the lathe
or machine when the mandril with its tube is revolved at a suitable speed while
the box A is held and traversed over the centre portion of the tube to reduce it in
thickness leaving the ends thick. The reduction may be done by traversing the
box A once over the tube or by doing so any number of times or with a reciproca-
ting action the tightening of the balls upon the tube being increased by screwing
sup the end E upon the cone c¹ or by other equivalent adjustment.
In preparing tubes for such purposes as the building of cycle frames I take a
tube say for instance 18 inches long and 18 inches external diameter and say one
thirty second thick. I then arrange the travel of the box so as to reduce the
thickness of the tube say 14 inches of its middle length leaving 2 inches at each
end not reduced. When the box has been traversed once or reciprocated any
desired number of times along the centre portion it will be found that the length
of the tube is increased and the thickness decreased until the desired thinness and
length is reached. If the tube is now examined it will be found that the metal
at the centre of reduced portion is greatly consolidated and improved in texture
and I shall have a thick ended tube very light but very strong on account of the
peculiar treatment it has received by the apparatus and process herein before
described. Such a tube is suitable at its thick end for uniting to sockets or junc-
tions either by brazing or by any other known means and when so mounted in a
frame the frame will be found much stronger and more reliable than frames made
either from tubes of parallel thickness or from tubes staved up at the ends by the
awkward means hitherto adapted in an experimental and limited degree. If it is
desired to have the shoulder of the tube inside at the ends this may be accomplished
by external pressure at the ends under dies or by a Ryder hammer or similar tool.
In the modification as shewn at Figures 5, 6, and 7 I reduce the centre portion of
the tube T by means of the three rolls R, R and R2 which are free to revolve on
their axes.
The lower rolls R¹ and R2 are mounted on their axles in the
housing or frame S which is recessed for this purpose as clearly shewn at Figure 6.
The centre portion of the housing is cut away so as to form the slot the sides of
which are formed V or similar shape and into this slot I fit the adjustable slide S¹
the ends being formed with a V or similar shaped groove to correspond with the
sides of the slot as clearly shewn at Figure 7. This adjustable slide is formed
with a bearing on its underside in which the axle of the upper adjustable roll R
fits, the said roll being held in position by the mandril M in which the tube T
is placed. I then fit into the upper end of the slot the loose piece 3 which is
held in position by the screwed pius s and 5 passing through the ends of the
housing or frame S and in the centre of this loose pieces I form a tapped hole to
receive the adjusting screw W the lower end of which bears upon the top of the
adjusting slide S₁ by which means the top roll R can be adjusted as required.
I have hitherto spoken of a reciprocating action of my reducing apparatus,
but I may where I deem it advisable perform the operation by a single traverse of
my said reducing apparatus. Instead of balls or revolving rolls or discs I may use
such equivalents as stationary rounded projections which produce a similar thin-
ning and lengthening effect (by means of a rubbing action) to that produced by a
rolling or revolving action.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
CLAIMS.

page_text: proving the texture of metal tubes consisting of the casing or reducing box A
fitted with balls B and operating upon the tube in the manner substantially as
herein set forth and illustrated upon the accompanying drawings at Figures 1, 2,
3 and 4.
Third: The apparatus for reducing the thickness of tubes consisting of the
box A in combination with the mandril M holding the tube T then operating as
herein set forth and shewn.
Fourth-The new or improved apparatus for reducing the thickness and im-
proving the texture of metal tubes consisting of the rolls such as R, R¹ and R³
mounted in the housing such as S and provided with the adjusting slide such
as S for adjusting the roll R in the manner and for the purpose substantially as
herein set forth and as shewn at Figures 5, 6, & 7.
Fifth The improvements in or pertaining to the manufacture of steel copper
or other metal tubes and in the apparatus employed in the said manufacture sub-
stantially as herein set forth and shewn upon the drawings.
Dated this 7th day of October 1897.
GEORGE BARKER,
Agent for Applicant, 77, Colmore Row, Birmingham.