Improvements in or relating to the Manufacture of Metal Tubing.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to the Manufacture of Metal Tubing.
We, WILLIAM JOSEPH GODDARD of 35 Hatton Garden in the County of London,
Secretary to a Public Company, JAMES RICHARD TRIGWELL of 146 Brixton Hill, in
the County of Surrey Cycle Manufacturer and ALFRED HENRY TRIGWELL' Of
35 Hatton Garden in the County of London, Mechanical Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the manufacture of metal tubing particularly suitable for
the manufacture of the frames of cycles and other vehicles.
In carrying out the invention we provide a strip of metal, say for example, steel of
the length of the tube to be made and of sufficient width to fold round so as to form
the tube of the required diameter plus the amount necessary for the joints. The
forming of the flat strip of metal into the tube is preferably effected by drawing it
through a succession of dies of the appropriate form and size. The joint may be
made in various ways, but in all cases-excepting where a separate strip of metal is
employed for the joint-both edges are folded so as to have one or more bends
engaging with each other, the parts of the joint being finally pressed together by
suitable pressure, conveniently by rolling the joint upon a mandrel which is inserted
at the proper part of the process.
Where a separate piece of metal is employed at the joint we form one or more
bends upon each of the edges to be joined and we provide a strip, the edges of which
are turned over so as to engage with the folded edges of the main strip thus holding
them together, the whole joint being consolidated by rolling or other pressure as
before described.
The extra strip may be applied at any convenient time so as to be folded with the
other portions as they pass together through the dies, or the extra strip may be
prepared separately and pushed or drawn into its position upon the other piece and
then consolidated as before described.
In order to further secure the joint or merely for the purpose of filling up the
slight channel which is apt to be left in a joint of this description solder, brazing or
dipping in molten metal may be used. Rivetting may be employed instead of or in
addition to the soldering if desired.
As above stated we may employ any convenient form of joint, but as a means of
providing great strength, we may use a sextuple joint, that is one having three thick-
nesses of metal in each part or two thicknesses on one side and four on the other,
each of the parts to be joined.
Dated this 3rd day of June 1896.
BOULT & WADE,
Agents for the Applicants

page_text: Improvements in or relating to the Manufacture of Metal Tubing.
We, WILLIAM JOSEPH GODDARD of 35 Hatton Garden, in the County of London,
Secretary to a Public Company, JAMES RICHARD TRIGWELL of 146 Brixton Hill, in
the County of Surrey, Cycle Manufacturer and ALFRED HENRY TRIGWELL of
35 Hatton Garden, in the County of London, Mechanical 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:-
This invention relates to the manufacture of metal tubing particularly suitable for
the manufacture of the frames of cycles, and other vehicles.
The invention may be carried out in the manner hereinafter described and illustrated
in the accompanying drawings of which
Figures 1 to 4 represent diagrammatically sections of tubes formed according to
our invention;
Figure 5 shows a section of a tube and a mandrel within it, and
Figure 6 is a plan of part of the drawing or forming apparatus used in manu-
facturing the tubes.
Figure 7 illustrates the progressive stages of manufacture of a tube, and
Figure 8 is a perspective view of a die.
In carrying out the invention we provide a strip of metal, say, for example, steel, of
the length of the tube to be made, and of sufficient width to fold round, so as to form
the tube of the required diameter, plus the amount necessary for the joint.
The joint may be made either with the edges of this strip of metal alone, as indicated
in Figures 1, 2 and 3 in which the strip is lettered A, or with the addition of a
separate strip a as in Figure 4.
When the strip of metal forming the body of the tube is employed alone, the joint
of the tube is formed by folding over both edges of the strip so as to have one or more
bends of one edge engaging with the bends of the other, in such a manner that the
folds composing the joint are placed inside the tube, as shown in Figures 1 to 3 and 5.
Any convenient number of bends may be employed, and they may engage in various
ways, examples of which are shown in Figures 1 to 3. As a means of providing
great strength we may use a sextuple joint, that is one having three thicknesses of
metal formed from each edge, as shown at Figure 3 or we may form the joint with
two thicknesses of one edge and four of the other as shown at Figure 2.
The forming of the flat strip of metal into a tube and the bending and engaging of
its edges to form the joint, are preferably effected by drawing it, in a well-known
manner through a succession of dies, of appropriate form and size, so as gradually to
approximate it to the desired form.
The number of dies employed may vary according to the quality and kind of metal
composing the strip, the number of folds given and the like. In manufacturing a
tube say such as is shown in Fig. 2, with two thicknesses of one edge and four of the
other, from a steel strip we find it convenient to employ nine dies slotted so as to form
the strip of metal progressively into the outlines shown in Figure 7 and numbered 1
to nine.
The dies are preferably formed of two steel plates screwed together as shown in
Fig. 8 which is a perspective view of a die which would give the metal strip the
outline shown at No. 5 of Figure 7.
The strip is introduced by hand into the slot in the first of the series of dies and
pulled through on the other side with pliers or other convenient tool giving it the

page_text: form shown at 1 of Figure 7. When a sufficient length has passed to enable a clutch.
or screw clamp to be affixed the die is placed in a groove in a rack or holder attached
to any suitable form of draw bench and the strip drawn through by a winch in the
well known manner until a sufficient length has passed to enable the strip to be placed
in the second die of the series. The strip is run su cessively through the whole series.
of dies in the same manner, being drawn at one operation through as many dies as the.
tenacity of the metal will allow. The strip remains open whilst passing through the
first five dies of the series, but is closed by the sixth which with the three following.
are hollow, and a mandrel is preferably employed with each of these dies. The first
mandrel may be preferably held in position by a wire secured to the centre of the.
preceding die as described hereafter with reference to Figure 6 which illustrates the
manufacture of a lighter form of tube, so that fewer dies are used and only one.
finishing mandrel. Each succeeding mandrel may be secured to the preceding one-
by a similar wire.
After being thus drawn into the desired shape, the parts of the joint are finally
pressed together by suitable pressure, preferably by rolling or drawing the tube upon
a mandrel, D, of the same diameter as the finished tube and provided with a.
recess, D', which receives the folds of the joint as shown at Figure 5.
Figure 6 shows in plan a portion of a draw bench and tube in process of manu--
facture. A is the metal strip, partly shaped but still open, where shown passing.
through the dies B, B1, B2, but formed into a closed tube by the dies B3 and B 4.
The dies are held in grooves in the rack ( D is a mandrel in this case of the same.
diameter as the finished tube and provided with a recess, which receives the folds of
the joint, as shown at D', Fig. 5. The mandrel is held in position by a 'wire E, one-
end of which is screwed into the mandrel, the other end is secured by a screw nut, E',
to the centre of the last die (B2) through which the strip A passes before being
closed. A die, F, is placed round the mandrel, to compress the joint, A', and ensure
regularity in the shape of the tube. If desired rollers may be employed instead of the
die, F, for this purpose.
When a separate strip of metal is employed in making the joint we form one or
mere bends on each edge of the main strip forming the tube, and likewise turn over-
the edges of the extra strip, so as to engage with the folded edges of the main strip.
and hold them together, as shown diagrammatically at Fig. 4.
The extra strip may be applied at any convenient time, so as to be folded with the
edges of the main strip as they are drawn, through the forming dies; or the extra
strip may be prepared separately, and pushed or drawn into its position upon the
main strip, and then consolidated on a mandrel by drawing or rolling as before
described.
In order to further secure the joint, or merely for the purpose of filling up the
slight channel which is apt to be left in a joint of this description, soldering, brazing,
or dipping in molten metal may be employed. Rivetting may be used instead of or
in addition to the soldering if desired.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. In the manufacture of metal pipes or tubes by drawing metal strips through a
series of forming dies, the employment of a mandrel attached to and held in position
by one of the said dies substantially as and for the purpose described.
2. A metal pipe or tube made from one strip of metal by bending both its edges
and engaging together the folds on the inside of the pipe or tube substantially as
described.
3. A metal pipe or tube formed from a strip of metal by locking the bent over
edges of such strip with a second strip of metal substantially as described and illustrated.
in Figure 4 of the accompanying drawings.
4. The complete metal pipe or tube substantially as described and illustrated.

page_text: respectively in Figure 1 or Figure 2, or
Figure 2, or Figure 3 or
drawings.
Figure 5 of the accompanying
Dated this 2nd day or April 1897.
WM. J. GODDARD.
J. RD. TRIGWELL.
A. H. TRIG WELL.
Boult & Wade,
Agents for the Applicants.
WM. J. GODDARD.
J. RD. TRIGWELL.
A. H. TRIGWELL.
Boult & Wade,
Agents for the Applicants.