Improvements in Speed-changing Mechanism or Driving-gear.
Year: 1896

page_text: Date of Application, 11th Aug.. 1896-Accepted, 19th Sept., 1896
COMPLETE SPECIFICATION.
Improvements in Speed-changing Mechanism or Driving-gear.
We, HARRY DE LYNE WEED, of No. 210 W. Granger Street, and FRANCIS
WEBSTER GRIDLEY, of No. 617 W. Onondaga Street, both of Syracuse,
Onondaga County, State of New York, United States of America 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:-
Our invention relates to chain-driven cycles and particularly to mechanisms for
changing the speed thereof, from high to low speed or nice-a-versa, all being done
by the rider without stopping the machine or removing the feet from the pedals.
Our object is to produce a new changeable speed mechanism for cycles,
comprising two sprocket wheels beside each other both mounted upon the axle of
the rear wheel or carried by it with suitable cam or eccentric mechanisms whereby
one of said sprockets can be shifted from a position concentric with the axle and
the other sprocket, to a position eccentric to both said axle and the other sprocket;
whereby when said sprockets are concentric with each other and with the axle,
the wheel is driven at slow speed because the driving chain is then engaged with
the larger, or slow-speed sprocket; when the larger one is shifted so as to become
eccentric to the smaller or high-speed sprocket, then the driving chain is in
engagement with both sprockets, but as the larger one is then loose and free to
rotate, the chain transmits all of its driving force to the smaller sprocket and the
cycle is driven at high speed; in which the larger sprocket is provided with means
whereby the chain is guided so as to be always in proper position to engage with
the smaller sprocket ; in which the larger sprocket consists of a ring mounted upon
an eccentric and that eccentric is mounted upon an iuner eccentric which is mounted
loosely upon the wheel-axle, both eccentrics being eccentric to the sprocket, to each
other and to the axle and means are provided by which said eccentrics are rotated
to shift the larger sprocket, in which also the smaller sprocket is at all times
concentric with said axle, and is the medium through which the driving force of
the chain is transmitted to the axle to drive the wheel, at slow speed when the
sprockets are interlocked, and at high speed when they are not; and in which a
pin in the outer eccentric engages with a camway in the periphery of the inner
eccentric whereby when said eccentrics are rotated, the outer one is shifted longi-
tudinally to either disengage the smaller sprocket from the other one and unlock
them, or to permit it to re-engage therewith, to lock them together, and in which
both eccentrics are rotated by a lever mechanism actuated by a rod which extends
up to a convenient point for the rider, as a little in front of the saddle.
Our invention consists in the several novel features of construction and
operation hereinafter described, and which are specifically set forth in the claims
hereunto annexed.
It is constructed as follows, reference being had to the accompanying drawings,
in which
Fig. 1 is a side elevation of the changeable speed mechanism as set at slow
speed.
Fig. 2 is a vertical section of the same.
Fig. 3 is a side elevation of Fig. 1, set at high speed.

page_text: Fig. 5 is an elevation of the outer face (or right hand face) of Fig. 1, the dotted
lines indicating the eccentric-shifting levers.
Fig. 6 is a like view of Fig. 3.
Fig. 7 is an elevation of the inner face, (on the left in Fig. 1).
Fig. 8 is a like view of Fig. 3.
Fig. 9 is an elevation showing the eccentric-shifting levers and eccentrics in the
positions shown in Fig. 1.
Fig. 10 is a like view of Fig. 3.
Fig. 11 is an elevation of the lesser eccentric and its lever, the dotted lines
indicating the cam-way.
Fig. 12 is a side elevation of Fig. 11.
Fig. 13 is an elevation of the greater eccentric and its lever.
Fig. 14 is a side elevation of the same.
Fig. 15 is a transverse section of the two eccentrics and axle showing the
cam-ways in one and the pin in the other.
Fig. 16 is a section of the guide-plate on the axle.
Fig. 17 is a front elevation thereof.
Fig. 18 is a rear elevation thereof.
A is a suitable axle, upon which an eccentric 2 is rotatably mounted, hereinafter
called the inner eccentric and upon this another eccentric 3 hereinafter called the
outer eccentric, is mounted rotatably, and in such relations that in one position the
outer eccentric is concentric with the axle (Figs. 5, 7 and 9) and in the other one
both are eccentric to the axle.
By a suitable ball-bearing joint 4 a sprocket-toothed ring 5 is rotatably mounted,
having a recess 6 in its inner face, having the teeth proper 7 partially overhanging
said recess and having a chain guiding rib or flange 8, here shown as created by
grooves 9, thus making the rib broken, for lightness, said grooves being adapted to
receive the outer side-bars of the chain-links and thereby guide the chain in its
longitudinal alignment. This sprocket is hereafter known as the greater
sprocket.
In Fig. 2, 10 (in dotted lines) indicates part of the hub of a cycle wheel, and
onto it another sprocket 11, (called the lesser sprocket) is screwed, or otherwise
firmly secured, so that it is at all times concentric with the axle.
In Figs. 1, 2 and 7 this lesser sprocket is shown as seated in the recess 6
with its teeth fitting into the notches in the outer edges thereof, so that the
two sprockets are connected together, the chain being only in engagement with
the greater sprocket and so that the lesser sprocket is driven at the same rate
of speed as the greater one, and the wheel is driven at slow speed. This recess
is partly shown in Fig. 8 and is the same form as the lesser sprocket and a
little larger so as to readily receive it and its teeth, the teeth thus performing
the function of a clutch to connect the two sprockets.
The inner eccentric is provided with an arm or lever 12 having a slot 13,
and the outer cccentric with a slotted arm or lever 14 offset as at 15, and both
levers are connected to a slide 16 by means of pins thereon which engage with
said slutways, said slide being provided with a slotway 17 which fits loosely onto
a stud or other projection 18 upon a collar 19 upon the axle.
The inner eccentric is provided with a cam-way 20 partly straight and partly
angular, and 21 is a pin inserted through the outer eccentric, so that when this
one is rotated, the outer eccentric is reciprocated one way to the position shown
in Fig. 4, by which the greater sprocket is moved out to release the lesser
sprocket. At the same time the rotation of both eccentrics, by the pulling up
of the slide, shifts the greater sprocket from its position in Fig. 7 concentric
with the axle, to that shown in Fig. 8 eccentric to the axle, and this brings its
then upper teeth into alignment with those of the lesser sprocket so that its teeth
enter the overhanging chain and the chain then drives the greater sprocket as
an idler and drives the wheel at high speed by the lesser sprocket alone. Then
when the slide is operated the other way, the rotation of the eccentrics retracts

page_text: the outer eccentric to the position shown in Fig. 2, raises the greater sprocket
into position concentric with the axle, and the lesser sprocket enters the recess in
the other and locks the two sprockets together and the wheel is then driven at
slow speed.
A suitable rod 22 is connected to the slide, and extends up to a point con-
venient for the rider, as to the upper cross-bar of a diamond frame in front of the
saddle.
It will be seen that the speed is changed from low to high, by simply shifting
the low speed or greater sprocket so that the lesser sprocket becomes the direct
means for driving the wheel, and the greater sprocket becomes simply an idler,
free to rotate upon the greater eccent ric, and that when the change is made from
a high to a low speed, the lesser sprocket becomes and is made a part of the
greater one, to connect it positively to the wheel, all without disengaging or
disconnecting the chain from the greater sprocket, or varying its tension; the
shift of the greater sprocket being made in a line vertical to the axle, and at a
right angle to the line of the crank-shaft.
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 :-
1. The combination, with a wheel and an axle upon which it revolves, of a
lesser sprocket secured to its hub and always concentric with said axle, and a
greater sprocket detachably connected to said lesser sprocket and in one position
concentric therewith, and means to shift said greater sprocket into a position
detached from and eccentric to said lesser sprocket whereby the power is applied
directly to the latter to drive the wheel.
2. The combination with a wheel and an axle upon which it revolves, of two
sprockets of unequal size detachably connected together, and means to disconnect
them and shift the greater sprocket eccentrically to bring part of its teeth into
alignment with those of the lesser sprocket which is secured to said wheel.
3. The combination with a wheel and its axle upon which it revolves, of two
sprockets of unequal size detachably connected together, and means to disconnect
them and shift the greater sprocket eccentrically to bring part of its teeth into
alignment with those of the lesser sprocket so that the teeth of the lesser sprocket
enter the links of the chain as it is guided by the greater sprocket.
4. The combination with a wheel, of a lesser sprocket secured to its hub, a
greater sprocket detachably connected to the lesser sprocket, and an eccentric
rotatably mounted and upon which the greater sprocket is rotatably mounted and
means to rotate said eccentric to bring the teeth cf said sprockets into or out of
alignment to engage doubly or singly with a chain.
5. The combination with a wheel, of a lesser sprocket secured to its hub, a
greater sprocket detachably connected to a lesser sprocket, an axle, an inner
eccentric secured thereon, a greater eccentric mounted upon said inner eccentric,
said greater sprocket being rotatably mounted upon said outer eccentric and means
to rotate said eccentrics, simultaneously to shift the greater sprocket to bring the
teeth of the lesser sprocket into engagement with a sprocket chain, or to disengage
it from the teeth of the lesser sprocket.
6. The combination with two eccentrics one within the other and eccentric to
each other, of two sprockets of unequal size, the greater sprocket being mounted
upon the greater eccentric, and the lesser sprocket being mounted upon a shaft
and adapted to engage with the other when said sprockets are concentric, and to
become disengaged from it when the greater eccentric is shifted by said eccentrics
into a position eccentric to the lesser sprocket, whereby said shaft is driven at
different speeds.
7. The combination with two eccentrics, one within the other and eccentric to
each other, of a slotted lever secured to each eccentric and a slide, engaging with
said levers, aud means to reciprocate it to rotate said eccentrics in opposite

page_text: directions, and shift the outer eccentric in a vertical line, whereby it is brought
into position either concentric with or eccentric to the shaft upon which the
eccentrics are mounted.
Dated this 11th day of August 1896.
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicants.