Improvements in or relating to the Manufacture of Bicycle-spokes..
Year: 1896

page_text: Date of Application, 3rd June, 1896-Accepted, 5th Sept., 1895
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Bicycle-spokes..
I, FRANZ KÜPPER, Merchant, of Aix-la-Chapelle, Rhenish Prussia, Germany
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 spokes of bicycles show generally a greater diameter at their ends than in
the other parts, and these thick ends are used to fasten the spokes in the nave
on the one side and in the rim on the other.
These spokes are manufactured in different ways.
Either the shaft which has
first the same diameter everywhere, is turned in the lathe at the middle part which
is to appear thin so that the ends remain thick and the whole spoke has now its
necessary form or the spoke is grinded off in the middle.
It is very necessary in bicycle-spokes, besides the solidity and elasticity, that
the neutral fibre of the spoke is under all conditions exactly in the middle of the
spoke; but it is in almost all cases impossible, either on the turners' lathe or by
grinding to get an everywhere equal diameter, owing to the very small diameter of
the spoke-cross-section and the particularly long length of the spoke. Besides
this, it is especially impossible that the centres of these cross-sections lie exactly
one above the other, or in other words, that the neutral fibre does occupy the
middle of the spoke, because in all places the circuit of the spoke is the same
and it is to be understood that spokes made in the above named manner cannot
fulfil the services that a perfect spoke should do.
A further defect of the above named method is, that through the loss of material
by twisting or grinding off the shaft, the firmness of the spoke is not increased, as
is done by my new method, but in contrary is reduced.
Another well known way of manufacturing spokes is by drawing the shaft with
a draw-bench.
But it is impossible to draw spokes with thick ends on both sides, because one
end of the spoke must be stuck through the eye of the bench and consequently
only the other end can remain thicker. By this method it is therefore possible to
make spokes with one thick end only.
This method has further the fault of deminuishing the strength of the material,
because the molecules of the same separate one from another in consequence of the
drawing.
Now, my new method of manufacturing spokes is, that the spokes are cold-
hammered or forged in that part, which is to be thinned. The hammer-work
can be put on at any desired place in the shaft, so that one cau first leave one end
of the shaft unhammered, and begin to work the hammer at any desired place, until
the shaft is thinned up to the other thick end, and after having hammered the
prescribed part of the shaft, one can put out of working the hammer as to have the
second end of the shaft unhammered.
A spoke with two thick ends is shown in the annexed drawing.
Spokes manufactured in this new manner show the following advantages against
those manufactured in the above named methods:
1. The spoke shows everywhere the same equal diameter; the neutral fibre or
spoke-nerve lies exactly in the middle of the spoke and the nerve is completely
untonched

page_text: 2. Besides that, the solidity of the spoke is greatly increased, not only while the
nerve of the spoke is not killed, but because the molecules are pressed together by
the hammering and the material gets much better.
3. This new way of manufacturing spokes by cold-hammering or forging enables
one to save material and to work quicker which is also cheaper with thorough
accuracy.
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 :
The manufacturing of spokes for bicycles with two thick ends by cold-hammering
or forging unthinned shafts in the parts that are to be thinned, and leaving the
two ends of the thickness of the unworked shafts, all substantially as described
and for the purpose specified.
JOSEPH MÖHLIG,
Agent for Applicant.