Improvements in the Tubular Frames of Velocipedes and other similar Light Vehicles.
Year: 1896

page_text: Date of Application, 27th Oct., 1896-Accepted, 2nd Jan., 1897
COMPLETE SPECIFICATION.
Improvements in the Tubular Frames of Velocipedes and other
similar Light Vehicles.
I BRUNO WESSELMANN of 54 Friedländer Weg, Göttingen, in the Empire of
Germany, 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 and accompanying drawings:-
My said invention relates to the tubular frames of bicycles, tricycles and other
light vehicles in which it is desirable to secure the maximum of strength with the
minimum of weight. The invention also tends to economise time and work in
putting the frames together and to attain increased security of the joints and
connections. In the improved form of tube which I produce under my invention
press or form in the tube, screw-thread or spiral convex ridges in single or multiple
threads which traverse the whole length of the tube and stiffen and strengthen the
same to such a degree that I am enabled to use lighter tubing than heretofore
and yet obtain equal or greater strength than is present in the tubing now
I
in use.
The said screw threads in the tubing can be utilized to further the connecting
of the tubes with the tee or corner pieces which unite the frame together, and these
connections can be made cold and with much greater speed, economy and security
than under present practice.
In order however to make.my invention well understood I will now proceed to
describe the same more fully and will refer in the course of the following description
to the annexed three sheets of illustrative drawings.
On Sheet 1, Fig. 1 is a side elevation of a bicycle frame made from tubing
treated and strengthened in accordance with my invention.
On Sheet 2, Fig. 2 is a similar view of a similar frame the difference being that
whereas in Fig. 1 the spiral threaded tubing is shown connected to the tee
pieces in the ordinary manner, in Fig. 2 the connection of the tubing to the
said tee pieces is effected by the utilization of the said spiral threads or
ridges.
On Sheet 3, Fig. 3 illustrates the method of and the appliance used for forcing
out or forming the said spiral convex ridges in the tubing while Fig. 4 shows the.
same appliance used for connecting the tubing to the tee pieces by the act or process
of forming the spiral ridges.
By forming the tubing with the spiral elevated ridges w the strength of the frame
is materially increased, so that I am enabled to use lighter or thinner tubing than
is now employed and yet obtain an equally strong frame, with the result that
the frame can with safety be made considerably lighter than at present.
Another advantage of the improved spirally ridged tubing over the plain tubing
is that in case of the machine being accidentally thrown down or coming against
any obstacle my improved form of tubing is not so easily dented or bulged in, as
is the case with plain tubing, the spiral ridges conferring great resisting power
gainst distortion or marking. In a plain tube a comparatively slight knock
will dint the tube, whereas with my ridged tubing no such result will follow,
and even if such should happen its presence is not so noticeable as in the plain
ube.

page_text: The improved spirally formed tubing might be formed or left with plain ends as
in Fig. 1, in which case the tubing would be connected to the tee or corner pieces a
by brazing or other usual hot process.
I might however as in Fig. 2 carry the spiral ridging right through to both
ends of the tube and utilize the said spiral ridging as a means of connection
between the tubing and the tee pieces. For example in Fig. 2 the tube 6 is
connected by the spiral ridging to the tee piece a, and the same connections occurs
between c and d, d and w and b and a'. In short all of the main connections or
joints of the frame may be made in this manner. The joints or connections so
made are firm and secure not only because of the powerful pressure under which
they are brought into intimate connection but owing also to the strengthening of
the parts by the spiral ridge form into which they are forced and by which they
are locked together.
The appliances whereby the said spiral ridges are formed in the tubing, and
whereby also the connections with the tee pieces are made, appear in Figs. 3 and 4
of the drawings. Referring to Fig. 3 I provide a mandrils formed at one end
with a screw thread i engaging with a fixed nut bracket m. The other end of the
mandril is furnished with a tapered tap k carrying single or multiple spiral
threading grounded on the back as shown, the threading 9 corresponding in pitch
to the pitch of the screw thread i. The length of the mandrils between the
commencement of the screw i and the tap k and also the length of the screw i
correspond to the length of the piece of tubing to be treated. The piece of tubing
is held in wooden or lead grippers such for instance as the grippers in Fig. 4,
and I then turn the screw i in the nut m by means of a key, hand wheel or the like
and thus revolve and draw the tap k through the tube, thereby causing the tap k
with its spiral ridges g to bulge out and form corresponding bulging spiral ridges w
in the tubing thus producing the desired form.
When connecting the tubing with the tee or corner pieces I first place the end of
the tube in the socket of the tee piece, as shown in Fig. 4, where the tube is
marked b and the tee piece a. I then grip the tube and socket together by the
lead or wooden grippers and screw forward the mandril s so as to pass the
threaded tap k along the tube. The convex spiral ridges forced outwards by
the threads g of the tap are formed primarily in the tube and secondarily in the
socket the tube and socket being thus locked and secured firmly together by the
spiral ridges. If the tee or corner pieces should be of cast metal, for instance of
cast steel, they may be cast with ridges corresponding to the spiral ridges of the
tubing, so that when the tap k is passed through the socket the ridges formed in
the tube are forced into the corresponding grooves in the socket. The threads
of the tap k might be single or multiple, and the said threads might be interrupted
instead of continuous or in lieu of such threads y I might mount on the tap k in a
spiral path, rounded steel pin projections or steel balls or rollers. When more than
one thread is used the threads might be of different heights.
g
Although I have in the foregoing description referred particularly to a bicycle
frame, my invention is nevertheless applicable to all velocipede frames or the
tubular framing of other light vehicles.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed 1 declare that what I
claim is.
1. The improved velocipede or other light vehicle frame composed of tubing
formed with screw-thread or spiral convex ridges, substantially as hereinbefore
described and as shown.
2. The improved appliance for pressing or forming spiral convex ridges in
tubing intended for use in the manufacture of velocipede or other light vehicle
frames, substantially as described and as illustrated in Fig. 3 of the drawings.
3. The improved method of connecting the tubular members of velocipede and

page_text: other light vehicle frames to the tee or corner pieces of the frame, in the
manner and by the means substantially as described and as shown in Fig. 4 of the
drawings.
For the Applicant,
E. K. DUTTON & Co.,
5 John Dalton Street, Manchester, Chartered Patent Agents.