Improvements in Driving Gear for Cycles and like Vehicles.
Year: 1896

page_text: Improvements in Driving Gear for Cycles and like Vehicles.
I, FRANCIS LEOPOLD SARJEANT, of Nanpantan, near Loughborough, in the County
of Leicester, Architect, do hereby declare the nature of this invention to be as
follows:
This invention relates to improvements in driving gear for cycles and like
vehicles, and it has for its object the attainment of greater speed from the same
amount of exertion on the part of the rider, and also the gaining of power in
ascending hills and the like.
For the purpose of my invention, the hub of the driving wheel is made of larger
diameter than usual, and is provided with an internally toothed ring, or its
equivalent; and I arrange, eccentrically and preferably below the centre of the
said toothed ring, a pinion which gears therewith.
This pinion is carried by an axle supported in the frame of the cycle, and which
axle also carries the smaller chain wheel. The teeth of the ring and the pinion
are enclosed, and kept free from dust and dirt, by two discs arranged one on each
side of the ring, and having ball bearings on which the ring can run. The axle
of the pinion passes through ball bearings in the said discs.
On rotating the larger chain wheel of the cycle, or like vehicle, by means of the
pedal crank in the ordinary way, the smaller chain wheel is caused to revolve,
and this, being fixed on the pinion axle, causes the pinion to perform one revolu-
tion for every revolution of the smaller chain wheel; and every revolution of the
pinion causes the toothed ring or hub to make a portion of a revolution, depending
on the relation of the pitch diameter of the pinion to that of the internally toothed
wheel.
The gain in power also depends on the relation of these pitch diameters, and
consequently the larger chain-wheel may have a greater diameter than .in cycles
as at present constructed. The employment of the internally, toothed ring or hub
attains the result desired with the minimum of weight.
Dated this 14th day of December 1896.
I, FRANCIS LEOPOLD SARJEANT, of Nanpantan, near Loughborough, in the County
of Leicester, Architect, do hereby declare the nature of this Invention and in what
[Price 8d.]

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accompanying
drawings and to the letters and figures marked thereon, that is to say:
This Invention relates to improvements in driving gear for cycles, and like
vehicles, and it has for its object the attainment of greater speed from the same
amount of exertion on the part of the rider, and also the gaining of power in
ascending hills, and the like.
For the purpose of my Invention the hub of the driving wheel is made of larger
diameter than usual, and is provided with an internally toothed ring, or its equiva-
lent; and I arrange eccentrically, and preferably below the centre of the said
toothed ring, a pinion which gears therewith. This pinion is carried by an axle
supported in the frame of the cycle, and which axle also carries the smaller chain
wheel. The teeth of the ring and the pinion are enclosed and kept free from dust
and dirt by two discs arranged one on each side of the ring, and having ball
bearings on which the ring can run. The axle of the pinion passes through ball.
bearings in the said discs.
On rotating the larger chain wheel of the cycle, or like vehicle, by means of the
pedal crank in the ordinary way, the smaller chain wheel is caused to revolve,
and this being fixed on the pinion axle causes the pinion to perform one revo-
lution for every revolution of the smaller chain wheel, and every revolution of the
pinion causes the toothed ring or hub to make a portion of a revolution, depending
on the relation of the pitch diameter of the pinion to that of the internally toothed
wheel.
. And in order that my Invention may be readily understood, I will describe the
same fully with reference to the annexed drawings, in which:
Fig. 1 is an elevation of the rear or driving wheel of a cycle with my improved
driving gear applied thereto, and
Fig. 2 is a horizontal section of the same.
a is the internally toothed ring or wheel which takes the place of, or forms the
hub, of the driving wheel, and to which the spokes are attached in the ordinary
or in any other convenient manner. c is the pinion or toothed wheel which is
keyed on the axle d of the small chain wheel e, and, by turning with this latter,
makes one revolution to one of said small chain wheel e. The pinion c is caused
to gear with the internally toothed ring a, by placing the centre of the chain wheel
axle d below the centre of the driving-wheel. The toothed ring a is fixed by
means of arms or spokes f, to discs or rings g, of which there is one at each side
of the wheel. These rings are mounted on balls h which run in grooves upon
discs . The ball bearings so constituted are completed by means of a screwed
ring or cone j. The discs i are formed with a central opening for the passage of
the axle d, and they are secured by brackets & to bearings !; or said discs i may
constitute the bearings for the axle. The space between the discs or rings 9 and
the rim of the wheel a, may, if desired, be covered with a case of celluloid, or other
light material, to keep the teeth of the ring and pinion free from dust and dirt.
The point of contact of the toothed ring a and pinion c, is in advance of the
point of contact y of the driving wheel periphery and the ground, when driving.
If the pinion c is less than half the diameter of the wheel a, a pin or axle may be
arranged through the centre of the, wheel, a to facilitate tightening up of the
bearings and i.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same may be performed, I would have it
understood that. I do not limit myself to the exact proportions nor to the details of
construction as shewn, but that what I claim is :-
1. In a cycle, or like vehicle, an internally toothed ring, forming the hub of the
driving wheel, carried by the frame of the machine and mounted eccentrically to
the axle of the small chain wheel, and a pinion on the axle of said chain wheel to

page_text: gear with such internally toothed ring, substantially as and for the purpose
described.
2. In a cycle, or like vehicle, a driving wheel having a hub formed as an
internally toothed ring, to which the spokes are attached, and which ring is con-
nected by arms to discs forming bearings and carried by brackets on the axle of the
small chain wheel, substantially as described and shewn.
3. My improvements in driving gear for cycles, and like vehicles, substantially
as hereinbefore described and shewn in the annexed drawings.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5A, Market Street, Nottingham,
Agent for the Applicant.