Improvements in Driving Gear for Cycles.
Year: 1896

page_text: Date of Application, 12th Aug., 1896
Complete Specification Left, 27th Nov., 1895-Accepted, 16th Jan., 1897
PROVISIONAL SPECIFICATION.
Improvements in Driving Gear for Cycles.
I, CHARLES BUCHANAN LAWSON, of 94 West Regent Street, in the City of
Glasgow, Commission Merchant, do hereby declare the nature of this invention to
be as follows:-
This invention which relates to driving gear for cycles has for its object to
obtain enhanced power. by so controlling the pedal as to increase its leverage and
velocity principally at the downstroke.
This is effected by securing each pedal on the outer end of a rod, bar or lever,
acting as an auxiliary crank and pivoted near its outer end to the extremity of the
ordinary or main crank, whilst its opposite or inner end is guided to slide or travel
to and fro in or on the back stay or on a guide piece attached to the frame in a
suitable position. Or the rod may be made to telescope into an oscillating guide
pivoted to the frame or it may be attached to a swing joint or otherwise guided or
pivoted.
The path of movement of the pedal is in general elliptical and its centre in
advance of the main crank axle.
In order to provide a strong bearing or joint at the point where the auxiliary
crank is pivoted to the main crank and also to save lateral space I form at that
part of the auxiliary crank a strong tube provided with ball bearings at each end
to receive a pin or axle fixed or formed at the extremity of the main crank.
The outer end of the auxiliary crauk which extends beyond the tube is preferably
situated at the outside edge of the tube, wide of the main crank, and bent or
inclined upwards so as to support the pedal about its mid length from beneath and
clear the tube. The portion of the auxiliary crank behind the tube joins the tube
at the inside edge as close to the main crank as possible.
This arrangement may be reversed the tube being on the main crank and the pin
or axle on the auxiliary crank or the tube may be dispensed with and the pedal
fixed in the usual way to a straight auxiliary crank or lever lying close to the main
crank.
Dated this 11th day of August 1896.
Improvements in Driving Gear for Cycles.
I, CHARLES BUCHANAN LAWSON, of 94 West Regent Street, in the City of
Glasgow, Commission Merchant, 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 which relates to driving gear for cycles has for its object to

page_text: obtain enhanced power by so controlling the pedal as to increase its leverage and
velocity principally at the down-stroke.
The invention is illustrated by the accompanying drawings Figure 1 being an
elevation and Figure 2 an inverted plan of the improved driving gear. Figure 3
is a sectional view of a detail of part of the gear and Figure 4 is an elevation of a
bicycle showing the driving gear in position.
The object of the invention is attained by securing each pedal A on the outer end
of a rod, bar or lever B acting as an auxiliary crank and pivoted near its outer
end to the extremity of a straight ordinary or main crank C whilst its opposite or
inner end is guided to travel by means of a roller D to and fro in or on the back
stay or between two parallel back stays or on a guide piece E attached to the
frame F in a suitable position.
The path of movement of the pedal A is in general elliptical and its centre in
advance of the main crank axle, as shown at Figure 1.
In order to provide a strong dust proof bearing or joint at the point where the
auxiliary crank B is pivoted to the main crank Cand also to save lateral space, I
form at that part of the auxiliary crank B a strong tube H provided with ball
bearings at each end to receive a pin or axle J fixed or formed at the extremity
of the main crank C, these bearings being adjustable in any ordinary manner.
The outer end of the auxiliary crank B which extends beyond the tube His
preferably situated as shown at Figure 2 at or near the outside edge of the tube,
wide of the main crank C, and bent or inclined upwards so as to support the pedal A
about its mid length from beneath and clear the tube H which tube is provided at
this end with a cap K or other covering to exclude dust. The portion of the
auxiliary crank B behind the tube H joins that tube at the inside edge as close to
the main crank C as possible.
This arrangement may be reversed, the tube H being on the main crank C and
the pin or axle J on the auxiliary crank B.
In order to obtain a steady and dust proof bearing for and to reduce the friction
of the roller D at the back end of the lever or auxiliary crank, I form the roller
integral with the pin or axle G as shown at Figure 3, and hollow out the roller so
as to form a shelf. This end of the lever or auxiliary crank B terminates in a
short tube L of small diameter provided with ball bearings M at each end to
receive the axle or pin of the roller, these bearings being adjustable in any
ordinary manner. One end of the tube enters the hollowed out portion of the
roller fitting it closely and a cap N or other covering is fitted on the opposite
end to exclude dust.
I am aware that it has been proposed to increase the effective length of the
cranks of a cycle by fitting the pedals on treadle levers jointed to the crank pins,
but in such cases the rear ends of the treadle levers have been controlled by such
means as swinging or oscillating guides pivoted on fixed centres requiring very
long levers the effective length of which varied at different positions and also the
introduction of additional moving parts, whereas under my invention, in which the
guides are fixed, the moving fulcrum of the treadle lever maintains its relative
distance from the crank pin; and furthermore it had formerly been found necessary
to bend outwards the cranks or set the pedals out of the centre line to obtain
sufficient clearance an objection which is obviated by the formation of tubula
bearings for the crank pins in the length of the treadle guide levers.
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
claim is :-
1. In driving gear for cycles the combination with each crank of an auxiliary
crank or treadle lever having formed on it a tubular bearing for the crank pin, a
support for a pedal at its forward end and a pin or roller at its rear end guided t
travel to and fro in a fixed guide substantially as described.
2. In driving gear for cycles an auxiliary crank or treadle guide lever having

page_text: formed integral with it a tubular bush carrying ball bearings for the crank pin
substantially as described.
Dated this 26th day of November 1896.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
St. Vincent Street, Glasgow, Agent for the Applicant.