An Improvement in Sprocket Wheels for Cycles and other Gear Wheels.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improvement in Sprocket Wheels for Cycles and other Gear
Wheels.
CHARLES HENRY LOGAN, Engineer, of No. 13, Clifton Square, London, S.E., WALTER
HENRY WEDDERBURN, Engineer, of 130, Hill Street, London, S.E., RICHARD HENRY
WHITE KNIGHT, Engineer, of 174, Upland Road, East Dulwich, London, S.E., do
hereby declare the nature of this invention to be as follows, namely:-
This invention consists in the construction of a sprocket or toothed gear wheel,
made partly of steel, or any other suitable metal; and partly of rubber or any other
suitable material having elasticity.-So constructed that the toothed rim of the
sprocket or gear wheel, shall be capable of a movement circumferentially either back-
ward or forward, independent of the movement of the hub: also capable of a
variation from its true perpendicular alignment either to the right or left while in
actual rotation, at its work for the purpose of always keeping the chain gear,
and the
wheel it is moving, in perfect alignment no matter how variable may be the chain
line from truth. Also to take up the lost motion and prevent back lash, and the
stretching or breaking of the chain from unequal strains.
Also for the purpose of
causing the chain to readily and quietly take its place on the sprocket teeth without
danger of stretching or undue wear of the ends or sides of the teeth.
This invention largely reduces the friction of the chain gear and also greatly
reduces vibration and jar. Any system of gearing using a sprocket or toothed wheel
as herein mentioned and especially cycles motors etc. must be capable of movement
by the application of less power than by the ordinary method of gearing.
D
1
.
An Improvement in Sprocket Wheels for Cycles and other Gear
Wheels.
We, CHARLES HENRY LOGAN, Engineer, of No. 13, Clifton Square, London, S.E.,
WALTER HENRY WEDDERBURN, Engineer, of 130, Hill Street, London, S.E., RICHARD
HENRY WHITE KNIGHT, Engineer, of 174, Upland Road, East Dulwich, London, S.E.,
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 relates to the construction of a sprocket or toothed gear wheel, made

page_text: partly of steel, or other suitable metal, and partly of rubber or other suitable elastic
material so that the toothed rim of the wheel is capable of a certain amount of
movement or play circumferentially and laterally relatively to the nave.
The circumferential play provides against sudden driving strains and the lateral
play allows the rim to accommodate itself to the line of the chain which can thus
readily and quietly take its place on the sprocket teeth without vibration and jar.
Fig. 1 of the accompanying drawings is an elevation with side plate removed of a
sprocket wheel according to this invention.
Fig 2 is a section of the wheel.
The rim A has 3 or more arms at projecting radially inwards and the nave B has
a corresponding number of arms 6 projecting radially outwards, the whole space
between rim and nave being filled with caoutchouc or other suitable elastic material
which envelopes the arms a and b. On the one side a plate C is fixed to the arms a
by rivets D passing through slotted holes of C in which the rivets have radial as well
as circumferential play. A plate E on the other side of the wheel is held to the nave
and the plate C by rivets F which pass through the arms 6 and the plate C when
the wheel is for a velocipede the pedal crank P is secured to the nave by rivets G.
Although we have shewn our invention applied to a sprocket wheel, it is obviously
applicable to any toothed wheels or set of gearing in all cases where it desired to
avoid sudden strains, jars and vibration.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, we declare that what
we claim is :-
A sprocket or toothed wheel having elastic material interposed between the nave
and the rim, substantially as and for the purpose set forth.