Improvements in Driving Gear for Bicycles.
Year: 1895

page_text: Date of Application, 9th Dec., 1895-Accepted, 8th Feb., 1896
COMPLETE SPECIFICATION.
Improvements in Driving Gear for Bicycles.
I, WILLIAM JENKINS, of the Village of Cashel, in the County of York, in the
Province of Ontario, Canada, Merchant, 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 :-
My invention relates to improvements in drive gear for bicycles and the object
of the invention is to design a compact and narrow form of internal speeding drive
gear for bicycles, which may be kept entirely free from dust and in which there
will be a minimum amount of torsion on the spindle of the driving sprocket wheel and
a minimum amount of friction between the internal gear and the driven pinion and
it consists essentially of constructing the internal gear with a shroud, an upwardly
extending arm for attaching the pedal thereto and a suitable covering for the
opposite side of the gear and further in providing a sprocket pinion adjacent
to the spur pinion, the parts being otherwise constructed so as to materially
reduce the width of the driven gear in the manner hereinafter more particularly
explained.
Fig. 1, is a perspective view of the journal box and gear for the bicycle constructed
in accordance with my invention.
Fig. 2 is a sectional plan of the gear, the main portion of the journal box being
broken away.
Fig. 3 is a side elevation showing the preferred form of arrangement of drive.
In the drawings like letters of reference indicate corresponding parts in each
figure.
A A¹ is the double journal box. B is the main driving axle, which is journalled
in suitable ball bearings in the journal box A and provided at one end with the
usual pedal crank C and at the other end with the internal drive gear D, which is
provided with an outside shroud D' and a recessed centre d¹ in the hub D².
The hub D is secured on the threaded end b of the axle B by a nut 6', which is
flush with the surface of the shroud, D'. By this means the width of the machine
is reduced.
D³ is an arm attached to or forming part of the internal gear wheel D and E is
the pedal, which is suitably secured thereto as shown. The arm D³ serves as a
substitute for the pedal crank and in this way considerably reduced the width of
the gear.
F is a driven spindle, which is journalled in suitable ball bearings and is
provided with a threaded end on which is secured the sprocket wheel G,
which is connected by sprocket chain H to the sprocket wheel on the main
driving wheel.
I is a spur pinion, which is secured on the threaded end of the spindle F to the
outside of the sprocket wheel G. The spur pinion I meshes with the internal
gear D. J is a shroud, which is suitably fastened to the journal box A A¹ by
suitable bolts j. This shroud serves to entirely close the internal gear and
keep it free from dust. The gear moves within the over-turned flange j' of the
shroud J.
In Fig. 3 in which I show the preferred form of arranging the drive it will be
seen that the force on the pinion is exerted at the rim of the internal drive in the
opposite direction to the pull of the chain on the sprocket wheel as indicated by
arrows, the chain in this case passing off from the rim of the wheel at about a

page_text: tangent to the pitch line of the teeth, so that it will be understood that the pressure
of the spindle of the spur pinion, actuated by the internal gear, on its bearing will
be reduced to a minimum.
As the sprocket pinion is situated on the same side as the spur pinion and close
to the internal gear it will be seen that the drive chain will be at the same side of
the machine as at present and also that the torsion on the driving spindle will be
very slight indeed.
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. The combination with the double journal box, pedal axle and internal gear
secured on one end of the pedal axle, of the driven spindle spur pinion meshing
with the internal gear and sprocket pinion adjacent to the spur pinion and the
sprocket chain as and for the purpose specified.
2. The combination with the double journal box, pedal axle and internal gear
secured on one end of the pedal axle and having an outwardly extending arm
attached to or forming part thereof, of the driven spindle spur pinion meshing with
the internal gear and sprocket pinion adjacent to the spur pinion and the sprocket
chain as and for the purpose specified.
3. The combination with the double journal box, pedal axle and internal gear
secured at one end of the pedal axle and provided with an external shroud, of the
driven spur pinion meshing with the internal gear and sprocket pinion adjacent to
the spur pinion and the sprocket chain as and for the purpose specified.
4. The combination with the double journal box, pedal axle and internal gear
secured at one end of the pedal axle and provided with an external shroud and a
.hub recessed in the centre to receive the end nut of the axle, of the driven spindle
spur pinion meshing with the internal gear and sprocket pinion adjacent to the
spur pinion and the sprocket chain as and for the purpose specified.
5. The combination with the double journal box, pedal axle and internal gear
secured at one end of the pedal axle provided with an external shroud, an internal
shroud and an inner shroud secured to the journal box, of the driven spindle spur
pinion meshing with the internal gear and sprocket pinion adjacent to the spur
pinion and the sprocket chain as and for the purpose specified.
6. The combination with the double journal box, pedal axle and internal gear
secured at one end of the pedal axle, of the driven spindle, spur pinion meshing with
the internal gear and sprocket pinion adjacent to the spur pinion and the sprocket
chain leading off from the sprocket pinion at a tangent to the gear as and for the
purpose specified.
1005
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.