An Improved Method of Manufacturing the Forks and other Constituent Parts of Cycle Frames.
Year: 1899

page_text: Date of Application, 19th Sept., 1899
Complete Specification Left, 19th June, 1900-Accepted, 21st July, 1900
PROVISIONAL SPECIFICATION.
An Improved Method of Manufacturing the Forks and other
Constituent Parts of Cycle Frames.
I, MARTIN MARCUS, of No. 123 Berlinerstrasse, Friedrichsfelde, near Berlin, in
the Empire of Germany, Manufacturer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to an improved method of manufacturing the back wheel
forks, stays and other flat tubular parts of cycle frames, and the object of my
invention is to obtain an economy of weight and of cost in manufacturing such
parts, as also to increase the rigidity and strength of such parts.
The improved method of my invention is particularly applicable for the back-
wheel forks or stays of cycles. The forks or bifurcated supports forming part of
the cycle frame as hitherto constructed were composed of five separate parts
jointed by brazing. To the cylindrical main tube, two bridge- or shoulder-pieces
used to be brazed and the flat or oval tubular branches of the fork were soldered
to the said shoulder-pieces. A yoke of this kind, accordingly, contains four seams
or soldered joints running across the tubes, and the said seams are particularly
liable to breaking, the more so, if, after soldering, the seams have been operated
upon by the file. To obtain the required strength of a cycle frame according
to this mode of manufacturing the forks, it has been found indispensable to
employ steel tubes of considerable size of metal, and, accordingly, of considerable
weight.
My invention consists in composing the forks or other tubular part of the cycle
frame of only two parts, prepared by stamping and jointed by means of a longi-
tudinal seam. Each half part of the fork or other tubular portion of the frame
is stamped as a whole, forming a trough, or troughs, and by laying the two semi-
circular or semi-oval halves with their edges upon each other, the tubular fork or
frame part will be completed with a longitudinal seam not liable to rupture.
Instead of brazing the two halves thus prepared with butt joints at their thin
metal-edges, I prefer to employ a rebate joint, the edges of one half fork or tube
being overlapped by the edges of the other half. By this means I not only
obtain a double strength of metal in the entire length of the longitudinal joints,
but also provide an increased surface for the brazing metal all along the seams.
Owing to this mode of composing the forks and other tubular parts of a cycle-
frame, the strength and resistance of the said parts is so much increased, that,
without endangering the rigidity and strength of the frame, the constituent parts
of the same may be manufactured of sheet steel of a minor size and weight than
could hitherto be employed with regard to the desired safety. Hence a consider-
able reduction of weight of material and of workmanship are obtained by this
improved method of manufacturing.

page_text: COMPLETE DELITICALION.
An Improved Method of Manufacturing the Forks and other
Constituent Parts of Cycle Frames.
I, MARTIN MARCUS, of No., 123, Berlinerstrasse, Friedrichsfelde, near Berlin, in
the Empire of Germany, Manufacturer, 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:—
My invention relates to an improved method of manufacturing the back wheel
forks, stays and other flat tubular parts of cycle-frames, and the object of my
invention is to obtain an economy of weight and of cost in manufacturing such
parts, as also to increase the rigidity and strength of such parts.
The improved method of my invention is particularly applicable for the back
wheel forks or stays of cycles. The forks or bifurcated supports forming part
of the cycle frame as hitherto constructed were composed of five separate parts
jointed by brazing. To the cylindrical main tube, two bridge- or shoulder-
pieces used to be brazed and the flat or oval tubular branches of the fork were
soldered to the said shoulder-pieces. A yoke of this kind, accordingly, contains
four seams or soldered joints running across the tubes, and the said seams are
particularly liable to breaking, the more so, if, after soldering, the seams have
been operated upon by the file. To obtain the required strength of a cycle-frame
according to this mode of manufacturing the forks, it has been found indispens-
able to employ steel-tubes of considerable size of metal, and, accordingly, of
considerable weight.
My invention consists in composing the forks or other tubular part of the cycle-
frame of only two parts, prepared by stamping and jointed by means of a longi-
tudinal seam. Each half part of the fork or other tubular portion of the frame
is stamped as a whole forming a trough, or troughs, and by laying the two semi-
circular or semi-oval halves with their edges upon each other, the tubular fork
or frame-part will be completed with a longitudinal seam not liable to rupture.
The accompanying drawings serve to illustrate my invention, in which,
Figure 1 is a plan view of one half a of the fork;"
Figure 2 is a plan view of the other half 6 of the fork;
Figure 3 is a cross section on the line A-B of Figure 1; and
Figure 4, a cross section on the line CD of Figure 2; and
Figure 5 is a cross section of one branch of the complete fork.
Instead of brazing the two halves a and b thus prepared with butt joints at
their thin metal edges, I prefer to employ a rebate joint, the edges of one half
fork or tube being overlapped by the edges of the other half as shown in Figure 5.
By this means I not only obtain a double strength of metal in the entire length
of the longitudinal joints, but also provide an increased surface for the brazing
metal all along the seams.
Owing to this mode of composing the forks and other tubular parts of a cycle
frame, the strength and resistance of the said parts is so much increased, that,
without endangering the rigidity and strength of the frame, the constituent parts
of the same may be manufactured of sheet-steel of a minor size and weight, than
could hitherto be employed with regard to the desired safety. Hence, a consider-
able reduction of weight, of material and of workmanship are obtained by this
improved method of manufacturing.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
:-
1. The method of manufacturing the forks and other constituent parts of cycle

page_text: frames, which consists in forming or stamping said forks or parts of two halves,
each half being an integral piece of metal, and jointing said halves by means of
rebate joints along the longitudinal edges, substantially as described."
2. A fork or stay for cycle frames, composed of two halves each being stamped
or formed of one integral piece of metal and the said halves being jointed along
their longitudinal edges by rebate joints, substantially as and for the purpose
described.
Dated this 19th day of June 1900
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.