Improvements in Chain Driving Gear.
Year: 1896

page_text: Date of Application, 17th Aug., 1896
Complete Specification Left, 16th June, 1897-Accepted, 17th July, 1897
We, JOHN THOMPSON, CHARLES EVERARD, and JOHN HARRISON trading as The
Elliptic Cycle Company, of 13, Brook Street, Peterborough, in the County of
Northampton, Manufacturers, do hereby declare the nature of this invention to
be as follows:-
This invention relates to improvements in driving gear mainly applicable for driving
cycles but also applicable for other driving purposes.
In carrying out our invention as applied to a cycle, we advantageously mount a
obain or sprocket wheel on each side of the hub of the driving wheel and a second
idle sprocket wheel on each side of the frame of the machine and we pass a chain
round cach pair of wheels and connect one link of the chains to bars or rods in con-
nection with the pedals so that when the pedals are actuated the points of connection
of the bars to the chains follow the movement of the chains round the wheels whereby
the said chains directly drive the driving-wheel of the machine. In some cases we
may dispense with the idle sprocket wheel.
With this arrangement it will be obvious that, as the number of revolutious of the
chain is directly dependent on the number of revolutions or oscillations of the pedal,
the speed of the machine can be varied by altering the number of links in the chain.
In some casos the pedal of the cycle can be directly connected to the chains.
It will bo also understood that instead of the chains directly driving the driving-
wheel of the machine, the said driving wheel can be operated by gearing driven by
the sprocket wheel.
Improvements in Chain Driving Gear.
We, JOHN THOMPSON, CHARLES EVERARD and JOHN HARRISON, trading as The
Elliptic Cycle Company, of 13, Brook Street, Peterborough, in the County of
Northampton, Manufacturers, 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 relates to improvements in driving gear mainly applicable for driving
cycles but also applicable for other driving purposes.
In carrying out our invention as applied to a cycle, we advantageously mount a chain
or sprocket wheel on each side of the hub of the driving wheel and a second idle

page_text: sprocket wheel on each side of the frame of the tuachine and we pass n chain round
each pair of wheels and connect one link of the chains to bars or rods in connection
with the pedals so that when the pedals are actuated the points of connection of the
bars to the chains follow the movements of the chains round the wheels whereby the
said chains directly drive the driving-wheel of the machine. In some cases we may
dispense with the idle sprocket wheel.
To enable our invention to be fully understood we will describe the same as applied
for example to a bioycle by reference to the accompanying drawing, in which:-
Figure 1 is a side elevation of part of a bicycle with our approved driving gear
applied thereto :
Figures 2, 3 and 4 are views illustrating the construction of the driving chain:
Figure 5 is a view similar to Figure 1, illustrating the application of our invention
to a ladies' cycle:
Figure 6 is a diagrammatic view hereinafter referred to.
Similar letters of reference illustrate corresponding parts in the several figures.
« is the frame of the machine, b is the driving wheel and c is a chain or sprocket
wheel fixed to the hub of the said wheel. d is the idle sprocket wheel which is
mounted upon an axle fixed upon the frame a or upon a bracket projecting from the
said fraine.
e is the chain which passes around the said sprocket wheels and which may be of
any suitable construction except that one of its links f is provided with a projecting
pin g.
h,hare the bars or rods through which the motion of the pedals is communicated
to the driving wheel.
As shewn in Figure 1 the bar is at its rear and pivoted to a pendulous link i and
at its front end provided with the usual pedal j; at a point between the two ends it
is connected to the pin g upon the chain.
With this arrangement it. will be understood that when the pedal is actuated the
chain will travel around the sprocket wheels c, d and thus impart motion to the
driving wheel the chain moving through a complete circuit for each up and down
movement of the pedal. As the number of revolutions or circuits of the chain is thus
dependent upon the oscillations of the pedal it will be obvious that the speed of the
machine can be varied by altering the number of links in the chain.
In order to maintain the pin g as rigid as possible relatively with the chain under
the pressure applied to to the pedal the link to which the pin g is applied is prefer-
ably made as shewn in Figures 2, 3 and 4, that is to say, with the two side plates of
the link connected by or formed in one with a bridge piecek.
In the modification of our invention shown in Figure 6 the arrangement of the
chain and sprocket wheels is the same as that herein before described, the pedal bar
or lever h, however, is directly pivoted to the frame a and is in the form of a bell-
crank lever one arm of which carries the pedal; whilst the other arm is connected by
a rod to the pin g of the chain as clearly shewn in the drawing.
Although we have described the sprocket wheels and ebain as being arranged in
conjunction with one pedal it is to be understood that in practice the arrangement
of chain gearing before described is applied in conjunction with each pedal. As
shewn in the drawing the chains e, e are arranged in such relative positions that the
pins g,g are at the dead points simultaneously. In order to prevent this we cause
each ping to travel through a slightly longer path when moving downwardly than
when moving upwardly for instance as shewn in Figure 0 by the employment of a
second idle wheel so that whilst the pin of one chain is moving from the lowest
dead centre to the upper one the other pin has not quite renched the lowest dead
centre, the movement necessary to effect this carrying the first mentioned pin over its
dead centre.
In cases where our invention is applied to a cycle in which the front wheel is to
serve as the driving wheel the pedals may be applied directly to the pins g the pedal
rods or levers A, A being dispensed with.
It will also be understood that instead of the chains directly driving the driving

page_text: wheel of the machine the said chains may operate a wheel connected with the
driving wheel by suitable gearing.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we declare that what we claim is :-
1. The improvements in driving gear consisting in the use of a chain passing round
two sprocket or chain wheels one of which is mounted upon or in connection with the
shaft to be driven whilst the other is an idle wheel, the motion to be transinitted
being communicated to the said chain through the medium of a pin carried by one of
the links of the same, substantially as described.
2. Chain driving gear for cycles wherein a driving chain is passed around two
sprocket wheels one of which is upon the axle of the driving wheel whilst the other is
an idle wheel the motion of the pedals being communicated to the said chain either
directly by means of a pedal mounted upon a pin carried by the said chain or through
the medium of a pedal lever connected to the said chain, substantially as described.
3. The manufacture and use of chain driving gear constructed, arranged and
operating substantially in the manner herein before described and illustrated in the
accompanying drawing.
Dated this foth day of June 1897.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.