Improvements in Two-speed Bicycle Gear.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Two-speed Bicycle Gear.
I, GUY RALSTON BALLOCH, Clerk, of Centreville, in the Province of New Bruns
wick and Dominion of Canada do hereby declare the nature of this invention
to be as follows: -
This invention relates to a two-speed bicycle gear and to means whereby the
rider may readily change from a high, to a low, gear or vice versa.
The wheel hub turns independently of the chain sprocket or other driven wheel
on ball bearings about the axle and the hub of the sprocket wheel respectively.
Within, and to opposite sides of, the hub are fixed bevelled gear wheels preferably
of different diameters and a double gear wheel formed of two wheels in one and
preferably of different diameters is mounted to rotate in ball bearings about an
eccentric disc fitted to slide upon the axle so as to cause the one or other members
of the double gear wheel to mesh with the corresponding gear wheel on the hub,
the smaller with the larger and the larger with the smaller respectively, at opposite
ends of a diameter. The chain or other driven wheel has a gear wheel in one
with it and always in gear with internal teeth of the double gear wheel notwith-
standing the sliding motion of the latter upon the axle produced by a spring
contained within the hollow axle and a pull rod passing through it and acting
oppositely on the eccentric disc. The pull rod is connected to a bell crank lever
pivoted on the stay of the frame and engaged by another lever connected by a
rod with a lever pivoted to the bottom bracket and connected with a bell crank
lever pivoted on the steering head and connected with a hand lever beneath the
handle bar. The gear wheels in the wheel hub or the two members of the double
wheel might be of the same diameter, the difference of diameter between the
two others being proportionately increased.
11. 01 love of Vaszombor 1807
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
I, GUY RALSTON BALLOCH, Clerk, of Centreville, in the Province of New Bruns-
wick and Dominion of Canada, do hereby declare the nature of this invention

page_text: 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 a two-speed or differential bicycle gear and to means
whereby the rider may readily change from a high to a low gear or vice versa,
and it comprises within a hollow drive wheel hub, differential gear wheels, a double
gear wheel laterally slidable for meshing with either of the said hub gear wheels,
and a driven sprocket wheel in gear with the said double gear wheel for rotating
the latter within the hub and permitting lateral movement of the same as will
be described with reference to the accompanying drawings forming a part of
this specification in which similar characters of reference indicate corresponding
parts in all the figures. Figure 1 is a section of the hub of the drive wheel con-
taining the differential gear, the section being taken on the line 1-1 of Figure 2.
Figure 2 is a reduced side elevation of the improvement as applied, with parts
broken out and parts in section, and Figure 3 is a plan view of a part of the
improvement.
The hub A of the rear or drive wheel of the bicycle is made hollow and is
mounted to turn at its sides on ball bearings B B of which the bearing B is
supported from a hollow axle C and the other bearing B₁ is carried by a sprocket
wheel D driven in the usual manner by the sprocket chain from the crank shaft
of the bicycle, as is well known, or by any mechanism operating a rear sprocket
or cog wheel. The sprocket wheel D is mounted to turn on ball bearings E E
supported from the hollow axle C as is plainly illustrated in Figure 1, so that the
hub A and the sprocket wheel D turn independently of one another. On the sides
of the hub A, and within the same, are arranged bevelled gear wheels F F¹, pre-
ferably of different diameters, as is plainly. indicated in Figure 1, and adapted
to be engaged by gear wheels G G₁ respectively, forming a double
gear wheel
mounted to rotate on ball bearings H held on a disc I eccentric to the hollow
axle C, as plainly indicated in Figure 1. Thus by the arrangement described
the gear wheel G is adapted to mesh with the gear wheel F at the upper part of
the latter while the large gear wheel G is adapted to mesh with the lower edge
of the gear wheel F". Instead of single ball bearings H, I may employ double
ball bearings if desired.
The double gear wheel G G¹, is rotated from the sprocket wheel D and for this
purpose the said double gear wheel is formed with an internal gear wheel G2 in
mesh with a gear wheel D' formed on an extension of the sprocket wheel D but
rigidly connected with the same. The teeth of the internal gear wheel G2 are
of sufficient length to allow of sliding the double gear wheel laterally in the
hub A so as to mesh with either of the gear wheels For F¹, without moving
the gear wheels D1 and G2 out of mesh.
The disc I is fitted to slide along the hollow axle C and for this purpose I
provide the hub of the said disc I with a pin I¹ passing through an elongated
slot C formed in the wall of the hollow axle C, and connected with a rod J
pressed on in a longitudinal direction by a spring J so as to hold the rod J
normally in an innermost position with the disc I and gear wheel G to the left
and with the gear wheel G in mesh with the gear wheel F.
The rod J extends through a cap 02 at the end of the hollow axle C and on
the outer threaded end of the said rod screws a nut J2 engaged by one end of a
bell crank lever K fulcrumed at K' to a bracket L held on the rear lower brace
of the bicycle frame, as is plainly indicated in Figure 2. The other arm of this
bell crank lever K is engaged by the upper end of a lever N, likewise fulcrumed
on the bracket L and connected at its lower end by a nut 01 held on a rod (
pivotally connected with a lever P fulcrumed at 1" on the crank hanger of the
bicycle, as is plainly shewn in Figure 2. The lever P is provided with an arm 12
pivotally connected by a rod 13 and a nut P with a bell crank lever Q connected
with a rod R having a head R' the upper end of the said rod being engaged by
a spring-pressed hand lever S extending under the handle bar and being under

page_text: the control of the rider, the said rod being also telescopically adjustable. Thus
when the rider presses the said lever S or releases the same, a lateral sliding motion
is given to the disk I to shift the double gear wheel laterally and move the gear
wheels G, G¹ in and out of mesh with their respective gear wheels F and F¹.
The lever S is normally held in an outermost position by a spring T, somewhat
stronger than the spring J¹, so that when the lever S is pressed upward toward
the handle grip, the spring J¹ is released and is permitted to force the disk I
and the double gear wheel to the left, to bring the wheel G in mesh with the
wheel F. When the pressure on the lever S is released, the spring T forces the
said lever into an outermost position, whereby the rod J is pulled outward against
the tension of the spring J, and the double gear wheel is shifted to the right
to move the gear wheels G and F out of mesh and the gear wheels G¹, F¹ into
mesh. It is evident that by the arrangement described, a high and low gear can
be made use of whenever desired, by the rider simply manipulating the lever S.
The difference in the size of the gears does not depend on a difference in the
diameters of the gear wheels G and G¹, or of the gear wheels F and F, but on
a difference between the gear wheels G and F and between the gear wheels G¹
and F. Gear wheels F and F or wheels G and G' may have the same diameters.
Of course, if one pair have equal diameters the other pair will have more difference
in their diameters than is shown in the drawings.
The entire device for transmitting motion to the drive wheel is completely
enclosed within the hollow hub A, and hence is completely protected against
dust and other impurities, and is not liable to get out of order. Any suitable
means may be employed for oiling the various parts.
Referring now to Figures 4, 5 and 6 which show a modification;
Figure is a longitudinal section of the hub of the drive wheel containing
the differential gear;
Figure 5 is a similar view of the same, with parts in a different position; and
Figure 6 is a cross section of part of the improvement on the line 6-6 of
Figure 4.
The hub A of the rear or drive wheel of the bicycle is made hollow, and is
mounted to turn at its sides on ball bearings B, B', of which the ball bearing B
is supported on a hollow axle C, and the other bearing B₁ is carried by the
sprocket wheel I adapted to be rotated by the usual sprocket chain from the
crank shaft of the bicycle, as is well known, or other suitable mechanism may be
employed for the same purpose.
The sprocket wheel D has its hub D' mounted to turn on ball bearings E, E',
supported from the hollow axle C, as is plainly shown in Figures 4 and 5, so that
the hub A and the sprocket wheel D turn independently of one another. The
hub D of the sprocket wheel D projects within the hub A, and is formed at
its inner end with longitudinally extending guideways D³, engaged by longitudinal
ribs F, formed on the inside of the hub of a gear wheel F, mounted to turn on
ball bearings E3 having their support E3 slidable on the hollow axle C. The gear
wheel F, by the arrangement described, turns with the hub D¹ and the sprocket
wheel D, and is free to slide longitudinally in the hub A, without moving out
of mesh with the sprocket wheel D.
The gear wheel F is provided on one end of its hub with clutch teeth F
adapted to engage with corresponding clutch teeth G on the right hand side of
the hub A, and the gear wheel F is adapted to mesh with the large gear H¹
of a double gear wheel H having its other small gear H2 always in mesh with
a beveled gear wheel J, formed on the inner face of the other side of the hub A.
The double gear wheel H is mounted to turn on a ball bearing I, the support I'
of which is secured to the hollow axle C, and the said ball bearing is arranged
in such a manner that the gear wheel H is eccentric to the gear wheels J and F
Now when the gear wheel F is shifted from the position shown in Figure 4
to the position shown in Figure 5, the clutch teeth F2 move out of mesh with
the teeth G, and the gear wheel F moves in mesh with the large gear H¹ of

page_text: the double gear wheel H. The rotary motion of the sprocket wheel D is now
transmitted by the gear wheel F to the gear wheel J, and consequently to the
hub A, at a reduced rate of speed but with greater power.
The support E is provided with a pin K, extending through an elongated slot C
formed in the hollow axle C, and the inner end of said pin K is connected with a
rod K¹, pressed on in a longitudinal direction by a spring L.
The rod K is
normally held in an outermost position as shown in Figure 4, by its connection
with a spring pressed lever N, on the handle bar of the bicycle. When this
lever is depressed by the rider, the rod K' is released so that the spring L is free
to move the pin K and the rod K' to the innermost position as shown in Figure 5,
with the gear wheel F in mesh with the gear H₁. The rod K' extends through
a cap C2 at one end of the hollow axle C, and the outer end of this rod K, is con-
nected with a suitable shifting mechanism under the control of the rider, and
preferably such as shown in Figures 1, 2 and 3 above referred to, so that further
description of the same is not deemed necessary.
The interior bearings can be readily lubricated, by introducing the oil through
suitable oil holes in the hollow axle shaft, and on the remaining bearings are
used the usual lubricating devices.
By the arrangement described, the entire device for transmitting motion to
the drive wheel is completely enclosed within the hollow hub A, and is thus pro-
tected against dust and other impurities, and is not liable to get out of order.
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. A differential bicycle gear, comprising a hollow drive wheel hub provided
with differential gear wheels, a double gear wheel laterally slidable for meshing
with either of the said hub gear wheels, and a driven sprocket wheel in gear with
the said double gear wheel, for rotating the latter within the hub and per-
mitting lateral movement of the same, substantially as shown and described.
2. A differential bicycle gear, comprising a hollow drive wheel hub provided
with differential gear wheels, a double gear wheel laterally slidable for meshing
with either of the said hub gear wheels, a driven sprocket wheel in gear with
the said double gear wheel, for rotating the latter within the hub and permitting
lateral movement of the same, and means, substantially as described, for shifting
the said double gear wheel laterally in the said hub, as set forth.
3. A differential bicycle gear, comprising an axle, a slidable gear wheel mounted
eccentrically on the said axle, and formed with two gear wheels of different
diameters, means for rotating the said slidable gear wheel from the driven sprocket
wheel, and gear wheels on the hub of the drive wheel, adapted to be engaged by
the gear wheels of the said slidable gear wheel, substantially as shown and
described.
4. A differential bicycle gear, comprising an axle, a slidable gear wheel mounted
eccentrically on the said axle, and formed with two gear wheels, means for rotating
the said slidable gear wheel from the driven sprocket wheel, gear wheels on the
hub of the drive wheel, and adapted to be engaged by the gear wheels of the said
slidable gear wheel, a disk slidably held on the said axle and carrying a bearing
for the said slidable gear wheel, and a spring pressed rod connected with the
said disk and extending within the said hollow axle, substantially as shown and
described.
5. A differential bicycle gear, comprising an axle, a slidable gear wheel mounted
eccentrically on the said axle, and formed with two gear wheels, means for rotating
the said slidable gear wheel from the driven sprocket wheel, gear wheels on the
hub of the drive wheel, and adapted to be engaged by the gear wheels of the said
slidable gear, a disk slidably held on the said axle and carrying a bearing for
the said slidable gear wheel, a spring pressed rod connected with the said disk
and extending within the said hollow axle, and means, substantially as described,
5

page_text: for imparting movement to the said rod in one direction from the handle bar of
the bicycle, as set forth.
6. A differential bicycle gear, comprising a hollow axle, a hollow drive wheel
hub concentric to the said axle, gear wheels secured to the inside of the said hub
at the sides thereof, a double beveled gear wheel fitted to slide laterally in the said
hub, and adapted to mesh with either of the said hub gear wheels, a disk fitted
to slide on the said axle, and carrying the said double beveled gear wheel, and
a sprocket wheel mounted to turn on the said axle and having a gear wheel in
mesh with an internal gear wheel formed on the said double bevelled gear wheel
substantially as shown and described.
7. A differential bicycle gear comprising a hollow axle, a hollow drive wheel
hub, concentric to the said axle, gear wheels secured to the inside of the said hub
at the sides thereof, a double bevelled gear wheel fitted to slide laterally in the
said hub and adapted to mesh with either of the said hub gear wheels, a disc
fitted to slide on the said axle and carrying the said double bevelled gear wheel,
a sprocket wheel mounted to turn on the said axle and having a gear wheel in
mesh with an internal gear wheel formed on the said double bevelled gear wheel
and means, substantially as described for moving the said disc laterally on the
said axle as set forth.
8. A differential gear wheel provided with a fixed axle, a hollow drive wheel
hub mounted to turn on said axle, an eccentric bearing rigidly secured on said
axle, and a driven gear wheel mounted to turn on the said eccentric bearing
and adapted to drive said hub substantially as shewn and described.
9. A differential gear comprising a hollow drive wheel hub provided with a gear
wheel concentric to the hub, a driven slidable gear wheel within the said hub and
concentric thereto and adapted to engage and directly drive the said hub, and an
intermediate gear wheel eccentrically mounted within the hub and adapted to be
engaged by the said slidable gear wheel substantially as shewn and described.
10. A differential gear comprising a hollow drive wheel hub provided at one
side with a gear wheel and at the other side with clutch teeth, a gear wheel
slidable in the hub and driven from the sprocket wheel and provided with clutch
teeth for engagement with the said hub clutch teeth, and an intermediate gear
wheel in mesh with the hub gear wheel and adapted to be engaged by the said
slidable gear wheel substantially as shewn and described.
11. A differential gear comprising a hollow drive wheel hub provided with
a gear wheel and clutch teeth, a driven sprocket wheel, a gear wheel mounted to
turn with and slide on the hub of the said sprocket wheel, the said slidable gear
wheel being provided with clutch teeth for engagement with the said hub clutch
teeth, and a double gear wheel eccentric to said slidable gear wheel and the hub
gear wheel, one of the gear wheels of the said double gear wheel being in mesh
with the hub gear wheel, and the other gear wheel of the said double gear wheel
being adapted to be engaged by the said slidable gear wheel substantially as
shewn and described.
سيم
1900
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.