Improvements in or relating to the Driving Appliances of Cycles.
Year: 1897

page_text: Date of Application, 17th Apr., 1897
Complete Specification Left, 8th Sept., 1897-Accepted, 5th Mar., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Driving Appliances of Cycles.
I, WILLIAM SPEIRS SIMPSON, of 49, Battersea Park Road, London, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for object improving the speed and lessening the power
necessary for driving cycles.
For the purpose of my invention I prepare a wheel with internal rim teeth into
which one or a pair of pinions engage as also with a central wheel. Each pinion
is carried from the main wheels centre to transmit the motion of the pedal or pedals
through the centre wheel to the outer or main wheel, which, would be the chain
or sprocket wheel from which the driving chain obtains its motion.
ML 1711
1 1007
R. CORE GARDNER,
Patent Agent,
166, Fleet Street, London,
Agent for the said W. S. Simpson.
Improvements in or relating to the Driving Appliances of Cycles.
I, WILLIAM SPEIRS SIMPSON, of 49, Battersea Park Road, London, Civil
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 object, improving the speed and lessening the power
necessary for driving cycles.
For the purpose of my invention, I prepare a rim on which the chain-carrying
sprocket teeth are arranged, said rim being supported peripherally on ball bearings
and secured by a face ring affixed to it. The chain-carrying sprocket or toothed
rim has internal teeth into which a series of pinions engage as also with a central
fixed wheel.
Each pinion aids to transmit the motion of the pedal or pedals by the action of
the centre fixed wheel to the chain wheel from which the driving chain obtains
its motion to the rear driving wheel of the machine.
My invention is clearly shown in the annexed drawings, Figure 1 being an in-
side elevation, and Figure 2 a partial plan view. A, is the chain or sprocket wheel
composed only of a rim with internal peripheral teeth B for rotation by the
These
pinions C, C, C, of which there are three for balancing purposes.

page_text: pinions C, C, C, are carried by a frame D on the boss E to which the shoulder F
of the pedal crank G is held in order that the frame 1) shall rotate therewith, the
pedal crank G being keyed to the crank axle H which is free to run in the ball
bearings I. The pinions C, C, C, are also in gear with a fixed central wheel J from
which they receive rotation upon their own axis K, K, K; while travelling round
the fixed wheel J and transmit rotatory motion to the annular rim or chain
wheel A which by the engagement of the links of the chain L with the gear M
on the hub or sprocket wheel N of the rear drive wheel causes the machine to
travel.
The sprocket rim or chain wheel A runs on ball bearings P which are held in
place by the face ring Q, and the pinions run on ball bearings R, the friction being
thus reduced to a minimum while complete peripheral support is given to the
chain driving wheel A.
The fixed wheel J is part of, or in a piece with, or connected to the bracket
socket S forming part of the frame of the machine.
In the sectional elevation I have shown the wheel J screwed into the bracket S
(from which the lower main stay, the centre stay, and the back fork are carried)
which occupy a position between the travelling wheels of the machine.
I am aware that epicyclic or differential gear has been more or less employed
in connection with the driving of cycles, I therefore make no claim broadly to such
method of or appliances for the purpose, I believe however that I am the first
discloser of a practical method of utilising this type of driving chain gear of cycles
as by reason of the particularly compact form and arrangement of the parts much
greater efficiency is secured than it has been possible to attain hitherto, besides
which they occupy no greater width than the existing direct crank sprocket chain
driver.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
I claim is:
1. The particular arrangement of appliances for epicyclic driving of a chain
wheel of a cycle as shown on the annexed drawings for the purpose set forth..
2. In a chain driving gear for speed purposes as described, the means for retain-
ing the ball bearings P in an annular channel and through them to localize the
pinions C, C, C, and their carying frame within the width of an ordinary chain
driver or sprocket A having internal rim teeth B for receiving motion from such
pinions C, C, C, which rotate while travelling round a wheel fixed to the machine
frame as herein described and shown.
The 8th day of September 1897.