Improvements in Frames for Cycles.
Year: 1893

page_text: Date of Application, 12th Apr., 1893-Accepted, 27th May, 1893
COMPLETE SPECIFICATION.
Improvements in Frames for Cycles.
I, FRANÇOIS AMÉDÉE BOURDICTION, of 56 Rue Sablouville, Neuilly on Seine,
in the Republic of France 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 for improvements in frames for cycles consists in connecting the
wheel forks to the main frame by flexible steel blades firmly fixed at each of their
ends and so arranged that their flexibility is utilized to suspend the frame without
the aid of any joints thus giving great rigidity in the lateral direction and great
flexibility in the vertical plane.
Figure 1 is an elevation of a bicycle frame constructed according to this
invention.
Figure is a back elevation and Figure 4'a part plan of the same.
Figure 3 is a similar view to Figure 1 showing the movement of the frame and
springs.
The frame A carries at its lower part and behind the bottom bracket two pro-
jections A' to which is secured the lower back wheel fork B. Each branch of this
fork B consists of a flexible steel blade wider and thicker at the end nearest the
projection A where it is firmly fastened and arranged in such manner as to bend
in the vertical plane. This blade is slightly curved in its length and carries on
one of its sides at the end opposite to the projection a bearing piece F raised
vertically in which is made an opening for the passage of the axle of the back
wheel. The upper back wheel fork C is rigid and its ends fit against the corre-
sponding bearing pieces F of the blades of the lower fork B and rest on the upper
face of these blades and are each bored with a hole to receive the axle of the back
wheel and are firmly forced against the pieces F by means of the two nuts on the
axle which prevent any rotating movement about this axle.
The branches of the fork C unite above the back wheel in such manner as to
leave a suitable space for the wheel and mud guard.
A very thin blade D connects the upper part of the fork to the upper and
back part of the frame A. This blade is arranged so as to bend in the direction
of the length of the machine and is solidly fixed to the fork C and to the
frame A.
Between the frame and this blade there is a rod E fixed at its lower end to the
upper part of the fork C, the upper part of this rod is free and terminates in a fork
fitting against the frame A when the jolting is severe.
The stay G is secured by the plate H and nuts I. The blade D is clamped
against the upper and back part of the frame A by means of the plate K and
bolts I.
Figure 3 shows an exaggerated movement in order to more clearly explain the
different parts of the back portion of this system. When a load is on the bicycle
the frame A sinks, the projections carry with them the extremity of the blades
fixed thereto-these blades which are normally somewhat curved become straight
and in this movement they bring forward the bearing pieces, the fork C is naturally
forced to follow the movement, its upper part moves forward and carries with it the
lower part of the blade D which is fixed thereto.
The rod E follows the movement of the fork C and if a sudden jolt is produced
this rod rests against the frame A by its fork. Figure 3 shows it under the
influence of a jolt but with a normal load the rod should not touch the frame.
It will be understood that the drawing is only an example of construction to

page_text: which I do not intend to limit myself reserving the right to modify the details as
experience may show to be preferable.
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. The improvements in cycle frames consisting in connecting the wheel forks to
the main frame by steel blades substantially as described.
2. The improvements in spring cycle frames substantially as described with
reference to the accompanying drawings.
Dated this 12th day of Anril 1893
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.