Improvements in the Manufacture of Velocipede Frames, but which are also applicable to the Manufacture of Metal Tubing for other purposes.
Year: 1897

page_text: Date of Application, 23rd Feb., 1897
Complete Specification Left, 23rd Nov., 1897-Accepted, 12th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Velocipede Frames, but which
are also applicable to the Manufacture of Metal Tubing for other
purposes.
I, WILLIAM HILLMAN, of 7, The Quadrant, Coventry, in the County of Warwick,
Engineer, do hereby declare the nature of this invention to be as follows:-
The invention has for its object improvements in the manufacture of metal
tubing to be used principally in the construction of velocipede frames but which is
useful for other purposes.
The purpose of my invention is to produce tubing of greater strength and rigidity
in proportion to its weight than has been attained by any of the processes hereto-
fore in use.
For this purpose I preferably take thin sheet cast steel of suitable width and
length and roll it by the aid of a pair of mandrels into the form of two tubes closely
adjoining each other and with the connecting web passing from one tube to the
other at the line of junction of the two tubes somewhat in the form of the figure 8
or passing straight across from the side of one tube to that of the other in a plane
parallel with one containing the axes of the two tubes.
In carrying my invention into effect I employ either cylindrical or slightly coni-
cal mandrels according to the shape of tubing I wish to make, I form a longitudinal
slit in each mandrel and preferably chamfer off one side of each slit; I insert one
edge of the strip of sheet cast steel in the slit of each mandrel and then rotate
the mandrels until the strip of sheet cast steel is rolled up into the desired form.
The strip of sheet metal may be of width to enable the tubes to be made of two or
more complete thicknesses all round or there may be only a comparatively small
overlap.
When the sheet metal is completely rolled up I pass over the same a pair of
retaining metal blocks perforated to the shape of the two juxtaposed tubes. I
then heat the tubing sufficiently to enable, preferably, soft solder to be run into
the V spaces between the two tubes, when the said solder will run in between the
double thickness of the tubing and firmly secure all together.
figure 8 tubing I first run in solder along one V space and then turn the tubing
When soldering the
over and run it in along the other V space.
By this means I am enabled to produce a tubing of high quality sheet cast steel
without materially reducing the hardness or stiffness thereof and consequently
without injury to the character of the metal used.
When constructing the frame of a velocipede I coil the tubing as above described
by the aid of mandrels and then hold it in position by the aid of jointed retaining
clips, I then insert the ends of the tubing into suitably shaped lugs or sockets and.
after the frame is thus built up I run in solder as above described into the tubing.
as also into the lugs or sockets so as to hold all firmly together without applying an
[Price 8d1

page_text: injurious heat thereto. After the solder has set I remove the jointed retaining
clips from the tubing.
Dated February 23rd 1897
f
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.
Improvements in the Manufacture of Velocipede Frames, but which
are also applicable to the Manufacture of Metal Tubing for other
purposes.
I, WILLIAM HILLMAN, of 7, The Quadrant, Coventry, in the County of Warwick,
Engineer, 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 invention has for its object improvements in the manufacture of metal
tubing to be used principally in the construction of velocipede frames, but which is
useful for other purposes.
The purpose of my invention is to produce tubing of greater strength and
rigidity in proportion to its weight than has been obtained by any of the processes
heretofore in use.
My invention is illustrated in the accompanying drawings, in which :-
Figs. 1 and 1 are end views of two pieces of tubing manufactured according to
my invention.
Fig. 2 is a plan, Fig. 3 a front elevation, Fig. 4 an end elevation, and Fig. 5 a
cross section, of apparatus suitable for manufacturing the said tubing.
Fig. 5 is a cross section drawn to an enlarged scale of parts of the apparatus
showing a piece of tubing partly manufactured, one circle having been formed
and the other in process of formation.
Fig. 6 is a cross section and Fig. 7 a side view of a mandrel forming part of said
apparatus, and
Fig. 8 is a plan and Fig. 9 an end view of a piece of tubing showing a clamp at
one end to hold it in position while being soldered.
In manufacturing tubing according to my invention I preferably take thin sheet
crucible cast steel of suitable width and length and roll it, by the aid of a mandrel a,
into the form of two tubes b b closely adjoining each other and with the connecting
web b passing from one to the other tangentially at the line of junction of the two
tubes, and somewhat in the form of the figure 8.
In carrying my invention into effect I employ either a cylindrical mandrel a
as shown in the drawings, or a slightly conical mandrel, according to the shape of
tubing I wish to make.
I form a longitudinal slit a' in the mandrel and preferably chamfer off or reduce
one side of the slit, as shown at a³.
The mandrel a is placed on the bed c of the tube-forming machine, and the
counterbalanced jaw d, hinged at e to such bed, is closed over the mandrel and
screwed down by the screw f and nut g, which latter is furnished with a lever
handle g¹ for facility of manipulation.
I insert one edge of the strip of sheet cast steel in the slit a¹ of the mandrel and
then, by the aid of the handles a³, rotate the mandrel until one side of the metal
strip is rolled up into the desired form, the lever nut 9. being gradually screwed
back as the rolling proceeds; the jaw d is then freed by unscrewing the lever
nut g, the sheet of metal with one tube formed is slidden off the mandrel, the edge

page_text: of the uncoiled part of the metal sheet is then inserted in the slit a¹ of the man-
drel a, the jaw à is then again screwed down and the operation repeated as before,
see Fig. 5, to complete the formation of the metal sheet into tubing of the form
shown at Figs. 1, 1, 8, 9.
The strip of sheet metal may be of width to enable the tubes to be made of two
or more complete thicknesses all round as represented in Fig. 1^, or there may be
only a more or less comparatively small overlap, such for example as that shown in
Fig. 1.
When the sheet metal is completely rolled up to the form shown, I clamp each
end thereof preferably by a hinged clamp h, the internal form of which is of the
shape of two juxta-posed tubes, and which is provided with a screw h¹ to secure the
jaws thereof together and to release the same. I then heat the tubing sufficiently
to enable preferably soft solder to be run into the V shaped spaces between the
two tubes, when the said solder will run in between the double thickness of the
tubing and firmly secure all together. The solder will, of course, be first run into
one V space and then into the other.
"
Or I may tin the sheet metal to form the tubes in any suitable manner and
then, when the tubing is formed, I, by the aid of heat, fuse the "tinning metal"
(solder) and thus secure or sweat it all together.
By this means I am enabled to produce a tubing of high quality sheet crucible
cast steel without materially reducing the hardness or stiffness thereof, and con-
sequently without injury to the character of the metal used.
I would here remark that I have mentioned high quality sheet crucible cast
steel as the metal I prefer to use in the manufacture of the improved tubing, but
other suitable high quality hard sheet metal may be employed so long as it shall
possess the required strength and rigidity.
When constructing the frame of a velocipede, I coil or roll the tubing by the
aid of a mandrel formed with a longitudinal slit as above described, and then hold
it in position by the aid of the jointed retaining clamps or clips h; I then insert
the ends of the tubing into suitably shaped lugs or sockets and, after the frame
is thus built up, I run solder as above described into the tubing, as also into the
Jugs or sockets, so as to hold all firmly together without applying an injurious
heat thereto. Or I may first "tin" the insides of the lugs or sockets and then
secure the tubes therein by applying the requisite heat to fuse the "tinning" metal.
After the solder has set I remove the jointed retaining clamps or clips h from the
tubing.
It will be observed that the chief advantage of my improved tubing as compared
with previous attempts to produce tubing from rolled or bent sheet metal, is to be
found in the great strength of my improved tubing at the point where the two
circles touch one another. At this point there are at least three (and it may be
five) thicknesses of metal, and the disposition of metal and solder is such that
great rigidity is the result.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. Tubing for velocipede frames and for other uses made of sheet metal coiled or
rolled into the form shown in Figs. 1 and 1* and secured by solder, substantially as
herein set forth.
2. The manufacture of tubing of sheet metal coiled or rolled into the form shown
in Figs. 1 and 1*, substantially in the manner hereinbefore described.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.