Improved Driving Mechanism for Bicycles and the like.
Year: 1898

page_text: Date of Application, 5th May, 1898-Accepted, 23rd July, 1898
COMPLETE SPECIFICATION.
Improved Driving Mechanism for Bicycles and the like.
We, LIONEL BRANDON, Gentleman, of "Oakbrook," Ravenscourt Park, and
THEODORE REICH, Photographer, of 64, Strode Road, Willesden Green, both in
the County of London, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:
This invention relates to an improved driving mechanism for bicycles and
the like and has for its object to allow a large driving wheel to be used without
unduly lengthening the stroke and in such a manner that the pedal has a large
leverage when being depressed and a small leverage on the return stroke. By
this means the power is used more advantageously than can otherwise be done.
In the accompanying drawings this invention is illustrated.
Fig. 1 is an elevation of so much of the driving gear of a bicycle as is necessary
in order to enable this invention to be understood.
Fig. 2 is an end view of Fig. 1.
Fig. 3 shews a simplified form of this improved mechanism.
In all these figures the same letters of reference indicate the same parts.
The main driving wheel A runs loose on the spindle a the latter being rigidly
fixed. On the spindle is provided an arm B projecting therefrom.
A
The end C of this arm is cross shaped and at b, b' has two intersecting slots.
bar D carrying the pedal D¹ has studs d, d which engage in the slots b b¹, a
sleeve E is fixed at the end of the bar D and embraces the crank F fixed on the
wheel A.
Now when the pedal is depressed in the direction of the arrows in Fig. 1 the
sleeve E depresses the crank and during the down stroke is at, or near the end
of the crank and hence in the most favourable position for exerting power upon
the same; on the return stroke the sleeve shifts towards the centre of the wheel
thus offering very little resistance. In this movement the crank F travels in
a circle the centre whereof is coincident with that of the wheel, whilst the bar D,
and with it the pedal, travels round a shifting centre, and in an elliptical path
the end of the bar travelling on the cross shaped part C, without however leaving
the same, being retained thereon by the studs d travelling in the slots b, b¹.
In order to reduce friction the edges of the crank F have grooves f, f, and
the sleeve E is fitted with anti-friction rollers e, e. By preference the rollers
are cone shaped and the grooves f, f, shaped to correspond therewith, as appears
best in Fig. 2.
In the simplified form shown in Fig. 3, a simple arm B₁ projects from the
spindle, and its end, c', is the fixed centre on which the bar Da rotates. The
bar D2 is connected with the crank by the same means as have hereinbefore been
described and carries the pedal.
In this form the pedal as well as the crank rotate in circular paths but, as the
sleeve shifts on the crank the leverage between these parts is altered so that in
this form also the distance of the pedal from the centre of the wheel is greatest
in the most effective part of the down stroke.

page_text: 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. A driving mechanism for bicycles and the like arranged as shewn in and
described with reference to Figs. 1 and 2 of the drawings.
2. A driving mechanism for bicycles and the like arranged as described with
reference to Fig. 3 of the drawings.
3. In a driving mechanism for bicycles and the like, such as herein above
described, the employment of rollers e, e, working in grooves f, f, substantially
as and for the purpose set forth..
1000
BERNHARD DUKES,
226, High Holborn, London, W.C.,
Agent for the Applicants.