An Improved Driving Gear or Means for Transmitting Movement in Cycles.
Year: 1897

page_text: Date of Application, 11th Sept., 1897-Accepted, 26th Mar., 1898
COMPLETE SPECIFICATION.
An Improved Driving Gear or Means for Transmitting Movement
in Cycles.
I, LÉON VIGNAL, of 34, Rue Laffitte, Paris, in the Republic of France, 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 has for its object an improved method of transmitting move-
ment in cycles by bevel gearings by means of a shaft in two parts, the connection
of these two parts forming a flexible arrangement capable of absorbing dynamic
deformations whilst leaving the gearings at their theoretical engagement.
The two parts of the bisected or divided transmission shaft which I employ
may be connected by any suitable means, and it is quite understood that the
coupling by tenons and mortices with a central plug, the description of which is
given hereafter, and which is one of the most practical forms, may be replaced
by any suitable mechanical arrangement capable of fulfilling the same object.
The characteristic and essential point of my invention consists in the use of a
suitable arrangement enabling the slight deformations which are produced in cycle
frames to be absorbed by the said arrangement or part. In a transmission by
means of a rigid shaft arranged on a system subjected to forces such as those
to which bevel gear transmission for cycles is exposed, the deformations are
transmitted to the gearing in contact and increase the friction. In my improved
arrangement these deformations are localised at a given point of the flexible part
and consequently the gearings always preserve their theoretic contact.
The transmission of movement is effected by means of four bevel wheels, two of
which are keyed respectively on the pedal shaft and the axle of the rear wheel.
Two others engage respectively with the first mentioned two, and are connected by
a shaft broken at one point and connected by means of a sleeve with tenons and
mortices, the utility of this interruption of the shaft having been indicated
herein before.
The invention will now be described with reference to the accompanying
drawings, in which,
Figure 1 is a plan; and
Figure 2, a vertical longitudinal section of the improved driving gear;
Figures 3 and 4 are end view and longitudinal section of the coupling end of
the transmission shaft; and
Figures 5 and 6 are side elevation and end view of the coupling piece.
The movement is transmitted as in ordinary safety bicycles by means of two
cranks A. B. The crank A has on its boss C a bevel wheel D (driving bevel wheel)
and it is fixed like the crank B on the pedal shaft by means of a key with washer
and nut. The bevel wheel D drives a bevel wheel E which is screwed on the
part F of the coupling sleeve bearing the mortices. The absolute fixture of the
wheel E on the part F is further obtained by means of nuts and lock nuts G H
on which rests a plate or race I for the travelling of the balls. The wheel E thus

page_text: .
formed has two cups or races. That which is on the side of the pedal shaft contains
balls K, that in the rear of the side of the mortices, balls L in a circular recess J.
The wheel E with double cups bears by means of these balls on two cones M and N
which are screwed in the interior of a steel box O having double ridges P. (forming
a groove between them) and attachment lugs or feet R. The wheel is thus held
in front and behind. The power it has to transmit is exerted between the two
points of support, and consequently it cannot have any tendency to reverse or to
jam the teeth.
The best conditions for realising continuously a theoretical engagement are
thus obtained. Further the cup J is placed in such a way that its ring of balls
are exactly at the point of contact of the primitive circles of the gearing, that is
to say at the point of application of the power to be transmitted and consequently
the resultant tangential of the power to be transmitted is destroyed.
The two coues M N when once fixed cannot be displaced. The small cone M
which is in front is threaded to the left and fixed by a counternut S threaded to the
right. It fits into a little recess which is formed in the pedal fork and which
prevents it turning. The large cone N is fixed by a key T which enters into a
boss of the box 0. These cones also serve for the adjustment, which, as may be
seen, is very easily effected. It suffices to slightly turn the cones M N by means
of a spanner in order to compensate for any wear of the balls or cones or even of
the bevel wheels.
The steel box which contains the whole movement is solidly fixed in a fork V
brazed on the pedal bracket or barrel. The two arms of this fork are in the
form of a cross and the internal wings or fins of the same enter into the groove
of the ridges P and assist in maintaining it and are terminated by threaded
tenons X on which the lugs R of the box 0 and of the coupling box Zare held
by means of nuts.
The coupling box is also brazed on the external tube U and it is in its interior
that the coupling of the two parts of the driving shaft Y revolves. The front
part is formed as hereinbefore shown by a part F having four mortices and in
the other part by a piece a having four tenons which are attached to the shaft Y
by means of a piece b.
The piece a terminated by a face with four tenons engaging in the corresponding
mortices of the piece F is screwed with a right hand thread on the piece band held
in place by two nuts cd screwed with a left hand thread on the same piece.
The driving shaft Y is formed of a hollow tube of any suitable thickness and
diameter, terminated in front by the piece soldered therein and behind by a
piece e also soldered on it. The piece to which is attached the piece a, as here-
inbefore shown, has further at its centre between the mortices a spherical nipple f
engaging in a recess g formed in the piece F in the direction of its axis. This
nipple serves to centre exactly the connecting sleeve according to the axis without
opposing itself to any deformations which the arrangement has for its object
to absorb, whilst preserving for the gearings a minimum of friction.
The piece e brazed at the other extremity of the driving tube Y receives a bevel
wheel E similar to the bevel wheel E and fixed in the manner hereinbefore described
for the said wheel E. The rear movement is mounted and works like that
of the pedal shaft. The regulating and bearing cones N¹ M¹ are fixed, the first
by means of a key T¹ passing into a boss formed in a steel box O¹ and the other
by two tenons h supported or arranged in the piece which serves as a support
for the axle of the rear wheel. These tenons h penetrate into corresponding holes
in the cone M: The holes are symmetrically placed as regards the axle so that there
are always two engaging the tenons h when the adjustment is made, whilst they
'are sufficient in number to afford a great capability or facility of adjustment.
The steel box is connected to the frame by a rear fork or loop piece V₁ brazed
'on the external tube, U. The two arms of the fork of this loop piece (the internal 5
wings or fins of which enter into a groove formed between the ridges P as was
the case in the box O in order to ensure the fixing) terminate also by means of

page_text: threaded tenons X¹ on which the lugs m of the box O¹ and the support 1 are
held by means of nuts.
A tube n for the saddle support is brazed on the support 7 which serves for
supporting the axle P of the rear wheel. The hub of the rear wheel revolves
on this axle and on this hub a bevel wheel D¹ is keyed which engages with the
bevel wheel E contained in the box 0. These movements are enclosed by the
external tube U and are contained in addition to the boxes 0 0¹ in attached
boxes having for their object to protect the gearing from dust and prevent the
introduction of any foreign body and at the same time to retain the lubricant.
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 transmitting movement in cycles of all kinds substantially
as hereinbefore described and illustrated in the accompanying drawings, the
essential and characteristic feature being the use of a shaft in two parts forming a
flexible organ capable of absorbing deformations which may be produced, the
arrangements employed for obtaining this result being capable of various modifica-
tions or variations, but I desire to claim the exclusive right to the principle itself
of this invention.
2. In a driving gear of the kind described, a transmission shaft (Y) brazed or
soldered to a piece (b) bearing a nipple (f) which penetrates into a recess (g)
in a sleeve (F) screwed in a bevel wheel (E) which receives movement from the
pedals by means of another bevel wheel (D) on the pedal shaft, a further piece (a)
being screwed on the aforesaid piece (b) and connected to the said sleeve (F) by
means of tenons and mortices, substantially as and for the purpose set forth.
3. In a driving gear of the kind described, the arrangement of bevel
wheels (EE) with double cups supported in front of and behind the point of
application of the power by a ring of balls, substantially as described.
4. In a driving gear of the kind described, the cones (M N M N¹) respectively
connected one with another by means of boxes 0 and O¹ and allowing the
tightening of the balls (K L or K' L') to be adjusted at will, substantially as
described.
5. In a driving gear of the kind described, the connection of the pedal shaft with
the rear wheel axle by means of a rigid arrangement surrounding or enclosing
the transmission parts and formed of a fork (V) surrounding the pedal shaft
and screwed on a fitting box Z itself soldered to a hollow shaft (U) on which at
its other end there is soldered a second fork (V2) screwed on the support (7) of
the axle (P) of the rear wheel, substantially as described.
6. The general construction and combination of parts taken as a whole forming
the improved driving gear, or means for transmitting movement lin cycles,
substantially as hereinbefore described and illustrated.
Dated this 10th day of September 1897.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.