An Improved Two Speed Bicycle Gear.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands
after Amendment (under Section 18 of the Patents, &c., Act, 1883), as
allowed by the decision of the Comptroller General of the 31st day of
March 1907
An Improved Two Speed Bicycle Gear.
1, CROWTHER BELL of Nottingham Road, Ripley, in the County of Derby,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to enable the rider to change from a high speed to
a low speed gear and vice-versa, while riding, and thus facilitate riding in hilly
country.
In carrying out my invention I provide a chain wheel of suitable diameter
running loosely in a certain position on the bottom bracket of the frame, the internal
periphery of this chain wheel is provided with teeth of suitable pitch arranged to
gear with one or more wheels attached to a disc on the crank these wheels also
gear with a central wheel of suitable diameter mounted on a hollow axle or sleeve
which can be locked to, or released from, the central axle by a suitable lever at will of
the rider.
The operation of my two speed gear is as follows:-The hollow axle being
locked causes the small intermediate wheels to be revolved in a forward motion also
driving the external wheel in the same direction causing it to move slightly quicker
than the crank, and connected up in such a manner that the leverage is more than
sufficient to cope with extra friction of the gearing. By actuating the lever the
hollow axle or sleeve is released and at the same time by a small device on same,
locked to the inner or central axle which revolve together and work just as a plain
gear for steep gradients. The communication with the driving wheel is by a chain
in the ordinary way and by altering the number of teeth on the driving wheel any
two given speeds may be obtained, and the whole is arranged in such a manner that
the change of speeds is only slightly felt.
My improved gear may be also arranged so that the feet may rest stationary on the
pedals when running down hill.
Dated this 96th day of March 1906
W. SWINDELL,
Imperial Chambers, Albert Street, Derby, Agent for the Applicant.

page_text: An Improved Two Speed Bicycle Gear.
I, CROWTHER BELL of Nottingham Road, Ripley in the County of Derby,
Mechanical 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:-
The object of my invention is to enable the rider to change from a high speed
gear to a low speed gear and vice-versa, while riding, and thus facilitate riding in a
hilly country.
In describing my invention reference will be had to the accompanying sheet of
drawings upon which :-
Figure 1 is a vertical section on line a. a. of Figure 2 shewing the different gear
wheels used in carrying out my invention.
Figure 2 is a vertical longitudinal section through the bottom bracket on line b. b.
of Figure 4.
Figure 3 is a elevation shewing the crank in relation to the three small gear
wheels.
Figure 4 is a vertical cross section through the bottom bracket on line c. c. of
Figure 2, shewing also the frame connections.
Figure 5 is an end elevation from point d.
The cranks A are keyed or otherwise fixed to the crank spindle B in the usual
manner. In carrying out my invention I provide a hollow spindle or sleeve C
encircling the crank spindle, the said hollow spindle or sleeve being caused to
revolve with the crank spindle or remain stationary as will be hereinafter explained;
ball races D are provided between the two, and ball races D are also provided
between the loose spindle or sleeve and the bottom bracket F of the frame. I further
provide a chain wheel G toothed as at H on its internal periphery, this chain wheel is
mounted loosely on the bottom bracket F or on the hollow spindle or sleeve C
by means of ball bearings I. A. central gear wheel K is fixed on the end of the loose
spindle or sleeve Cand revolves or remains stationary with it as required. Fixed to the
crank A is a disc L carrying one or more and preferably three small gear wheels M
which gear with the central wheel K and with the teeth on the internal periphery
of the chain wheel G, one of these small wheels M' may be connected direct through
the crank as shewn if desired.
For operating the mechanism I provide a rod N which may be carried by suitable
joints or connections to any part of the machine convenient for the rider, this rod is
connected at its lower end to a cranked arm O pivotted to the frame of the machine,
the inner end of the said arm being suitably connected to and adapted to move
a piston P which is kept normally pressed down by a strong spring preferably
concealed in the frame of the machine, the piston P terminates in a foot or
projection P which fits between two lugs or annular bearings R on the hollow
spindle or sleeve C, between these two bearings or lugs is pivotted an arm S
terminating at one end in a pawl or catch T and at the other is provided with a
small spring U the latter fitting also in a recess V in the hollow spindle or sleeve C.
The crank spindle B is provided with an annular projection or ring W in which
are formed recesses X of any convenient number adapted to receive the pawl or
catch T.
When driving on the high gear the spring Q pressing down the piston P causes the
pawl or catch T to be disengaged from the notches or recesses X, the crank spindle
now revolves free of the hollow spindle or sleeve C and carries with it the disc L
and small gear wheels M which as already stated gear with the central wheel K
(now-standing still with the hollow axle) and also with the toothed internal periphery

page_text: of the chain wheel and thus cause the said chain wheel to revolve at an increased
speed.
When it is desired to drive on the low gear the rod N is pressed down thus raising
the piston P by means of the cranked arm O until the small spring U comes into
operation and causes the pawl or catch T to engage one of the recesses X in the
crank spindle B which causes the hollow spindle or sleeve to be carried round with
the crank spindle, the central gear wheel thus driving the three smaller gear
wheels and communicating motion on the low gear to the chain wheel.
When the rod N is released the spring Qinstantly pressed down the piston P
and so releases the pawl or catch T from the recess X the machine being again on the
high gear.
It will be understood that the hollow axle or sleeve C revolves in the same
direction as the crank axle except when the pedals are held stationary the hollow axle
then revolving in the opposite direction.
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 I
claim is :-
1. In a variable speed gear for velocipedes having an internally toothed chain
wheel G gearing with three pinions M mounted on a disc L fixed to the crank A
or fixed direct to the crank, and also with central pinion K fixed to the hollow spindle
on sleeve C encircling the crank spindle B the improved means of operating said
variable speed gear consisting of a rod N and crank O' in combination with a piston P
set up by a spring Q to an arm S pivotted between two lugs or annular rings R on a
hollow axle or sleeve C, the pawl or catch T adapted to engage recesses ✗ in an
annulus W on the crank spindle B, the pawl or catch T being set up to recesses X by
a spring U substantially as and for the purposes described and illustrated.
2. The whole substantially as and for the purposes described and illustrated.
Dated this 27th day of June 1806
W. SWINDELL,
Imperial Chambers, Albert Street, Derby, Ágent for the Applicant.