An Improved Method for Driving the Wheels of a Bicycle or other Vehicle.
Year: 1895

page_text: Date of Application, 16th Apr., 1895-Accepted, 22nd June, 1895
COMPLETE SPECIFICATION.
An Improved Method for Driving the Wheels of a Bicycle or other
Vehicle.
We JANES WALLACE TYGARD, Pressman and THE TYGARD-Pollman
COMPANY LIMITED all of 284 Second Avenue, Pittsburg in the County of
Allegheny and State of Pennsylvania, 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 :-
My invention relates to an improved method for driving the wheels of a bicycle
or other vehicle, and its novelty will be understood from the following description
and claims when taken with the drawing in which:
Figure 1, is a rear side view of the device as it appears with the ball-bearing
side of the sprocket hub removed at sectional line x, in Figure 3.
Figure 2, is a front side view of device as it appears with the centre and hub of
driving wheel C, removed at sectional line 2, in Figure 3.
Figure 3, is a vertical section of the entire device applied to the driving shaft of
a bicycle.
To the driving shaft of the bicycle or other vehicle is attached a wheel C,
containing in its rim an internal bevel gear. A short distance from this wheel and
on same shaft is fastened an external bevel gear B, with face opposite the larger
internal bevel gear. The rear side of this gear B, is formed with a circular curve,
thus forming one of the cones for the ball bearing of the shaft. This gear B, is
of a proportionately smaller diameter than bevel gear C, to produce desired
difference in speed. These two gears on the same shaft constitute the mechanism
that drives wheel A, when device is used on the crank shaft of a bicycle. When
the device is used upon the rear bicycle wheel these gears become the driven instead
of drivers.
Working in the gear of internal bevel wheel C, is a sprocket wheel A, on whose
hub is formed an external and an internal bevel gear face. The outside of the
other end of wheel A's hub is formed to constitute part of the ball bearing on
which it revolves.
The outer face of wheel A, may be either a cogged surface, a sprocket, a pulley
face, or may have spokes and a rim. This wheel A, with a double gear on its hub,
revolves in an independent and parallel bearing from that in which the driving
shaft carrying the gear wheels B, and C, revolve. This bearing is formed on a
double threaded sleeve G, H, and preferably I use the ordinary ball bearing. The
other end of the stationary part of this sleeve is firmly attached to the frame of
the machine.
Upon the movable part of this sleeve G, is formed an actuating arm K, which
upon being rotated to the right, causes the movable part of sleeve to partly
revolve, thus carrying its outer end forward end wise, and causing sprocket wheel A,
to move end wise and the external teeth on its hub E, to mesh into and engage
internal gear in the rim of driven wheel C, at same time disengaging internal
gear E, from gear B. The device will then cause sprocket wheel A, to revolve at
a fast speed and wheel C, having a larger pitch diameter than the external bevel
gear on the sprocket hub E, a smaller sprocket wheel may be used, than at
present.
By rotating arm K, to the left, wheel A, is withdrawn from mesh with
wheel C, and further movement causes the internal gear on hub of wheel A,

page_text: "
at E, to engage in the teeth of the smaller external gear B, on shaft. The
wheel A, is then driven at the slow speed and the power of the riders foot upon
the pedal either in propelling machine or retarding pedal motion in descending
grades, is proportionately increased.
These changes may be made instantly and while riding at any speed.
The sleeve arm K, may be moved by hand direct or may be actuated from the
handles of the machine by the ordinary brake lever.
It will be readily seen that this device will work equally satisfactory should the
driving gears be moved end wise instead of the driven wheel as shown.
In the foregoing Specification and drawing, the terms "bevel" internal and
external gears, are used; however the invention will also work with other than
bevel gears. Crown or face gears and straight or spur gears 'may be employed.
The bevel gear which is preferred, has a little more clearance or space at the
pitch line than is common in an external bevel gear wheel.
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 of a bearing comprising a stationary member, and a
laterally movable member connected by screw threads, a gear revolving on the
movable member, and having internal and external gear teeth and an internal
gear and an external gear whose bearings are stationary, adapted to be engaged by
the external and internal gear teeth, respectively, of the gear on the movable
member of the bearing, substantially as specified.
2. The combination of two sets of interrial and external bevel gears on parallel
though independent bearings, and a double sleeve having its sections connected
together by screw threads and one of said 'sections carrying one set of internal
and external gears whereby the same may be moved laterally, substantially as
specified.
3. A bicycle or other vehicle having in combination a shaft journaled in fixed
bearings and carrying an external gear and an internal gear, a sleeve, surrounding
'the shaft and comprising a fixed meinber and a laterally 'movable member
connected by screw threads, a sprocket wheel having its bearing on the movable
member of the sleeve and provided with an internal gear and an external gear,
"and" means for turning the 'movable member of the sleeve, substantially as
specified.
Death ath'den of Al*1005
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.