Improvements in Driving Gear for Bicycles.
Year: 1899

page_text: Date of Application, 16th Aug., 1899
Complete Specification Left, 16th May, 1900-Accepted, 23rd June, 1900
Improvements in Driving Gear for Bicycles.
We, WILLIAM CHEETHAM, of 11, Nutgrove Road, Thatto Heath, in the County
of Lancaster, Insurance Agent, and JOSEPH CHEETHAM, of 27, South Street,
Thatto Heath, in the County of Lancaster, Collier, do hereby declare the nature
of this invention to be as follows:--
2
The object of this invention is to provide driving gear for bicycles whereby
high ratio of gearing between the crank spindle and the driving wheel can be
obtained without the use of excessively large wheels, and whereby the ratio
may be readily changed; and to so arrange the gear that the bearings may be
strongly supported.
For these purposes we arrange above the crank spindle an auxiliary spindle
carried in bearings in a bracket supported by struts or stays between the bottom
tube and back tube of the frame and also if desired by a strut from the bottom
bracket. The auxiliary spindle has a chain wheel at each end, one of which
wheels is geared by a chain with a chain wheel on the crank spindle, the other
being geared with the chain wheel on the hub of the driving wheel. By this
means the strain on the auxiliary spindle is evenly balanced. The chain wheel
cn the crank spindle and its corresponding wheel on the auxiliary spindle are
made removable so that by using wheels of different relative sizes the ratio of
gearing may be varied to any degree desired. The bearings of the auxiliary
spindle may be made adjustable to allow of taking up the wear of the chain.
P
I 1000
We, WILLIAM CHEETHAM, of 11, Nutgrove Road, Thatto Heath, in the County
of Lancaster, Insurance Agent, and JOSEPH CHEETHAM, of 27, South Street,
Thatto Heath, in the County of Lancaster, Collier, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
arly described and ascertained in and by the following statement, reference
being had to the accompanying drawings:-
The object of this invention is to provide driving gear for bicycles whereby
high ratio of gearing between the crank spindle and the driving wheel can be
obtained without the use of excessively large wheels, and whereby the ratio

page_text: may be readily changed; and to so arrange the gear that the bearings may be
strongly supported.
For these purposes we arrange the gear substantially as shown in the draw-
ings in which Fig. 1 is a side view of so much of a bicycle as is necessary to
illustrate our invention and Fig. 2 is a view with part of the driving gear
removed, a is an auxiliary spindle arranged above the main crank spindle b and
carried in bearings of any usual kind supported in a bracket d which is
secured by struts or stays e between the bottom tube f and back tube g of the
frame. The bracket may be further supported by a strut or stay h
from the bottom bracket i. The auxiliary spindle a is provided with chain
wheels one at each end, the wheel being geared by a chain / with the
chain wheel m on the crank spindle and the wheel being geared by a chain n
with the chain wheel o on the hub of the driving wheel p. By this means the
strain on the auxiliary spindle is balanced. The stays e and h hold the bracket d
rigidly in position. The chain wheels j and m are made removable so that by
using wheels of different relative sizes on the spindles a and b the ratio of gear-
ing may be varied to any degree desired whilst keeping all the wheels of com-
paratively small size. The bearings c are preferably carried excentrically in
the bracket d in any usual way so that the bearings with the spindle and wheels
thereon may be adjusted for the purpose of taking up any slack in the chains.
The bearings as will be obvious may be arranged so that the slack in either chain
or in both can be taken up.
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:-
The combination with a bicycle of a bracket arranged above the crank spindle,
struts or stays from the bottom and back tubes and bottom bracket to the said
bracket, an auxiliary spindle carried in bearings in the bracket, chain wheels
on the auxiliary spindle, and chains connecting the chain wheels on the auxiliary
spindle to chain wheels on the crank spindle and driving wheel all substantially
as and for the purpose set forth.
1000