Improved Bicycle Gear.
Year: 1897

page_text: Date of Application, 9th Sept., 1897
Complete Specification Left, 7th June, 1898-Accepted, 6th Aug., 1898
Improved Bicycle Gear.
I, GEORGE THOMAS MARTIN, of the Town of Smith's Falls, in the County of
Lanark, and Province of Ontario, Canada, Architect, do hereby declare the nature
of this invention to be as follows:
The object of the invention is to provide a bicycle gear which is compact in
form and simple in construction, whereby great speed may be imparted to the
sprocket-chain wheel without undue expenditure of power, and it consists, essen-
tially, in mounting the sprocket chain wheel on a hollow mandrel which is sleeved
on the pedal shaft and connecting the hollow mandrel to the pedal shaft by a
series of gear wheels, substantially as hereinafter described and then definitely
claimed.
Figure 1, is a sectional elevation of my improved gear.
Figure 2, is a perspective view partly broken away the device being turned
end for end as compared with Fig. 1.
In the drawings, like letters of reference indicate corresponding parts in the
different figures.
In the several figures, A, is a pedal shaft provided towards either end with the
ball bearing cones A', and shouldered preferably at a, a, so that the parts may
be held more securely.
C, is a bevel gear wheel which is screwed on, or otherwise fixed to the pedal
shaft near the end opposite to that on which the chain sprocket wheel is located.
D, is a housing, which is preferably cylindrical in form, as indicated in Fig. 2,
and which is secured to the seat stem and diagonal brace of the bicycle frame in
the manner indicated. This housing D, has an aperture cut therein for the pur-
pose of permitting the gear wheel F, hereinafter referred to, to pass through,
and it is provided with the strengthening flap D', which serves to prevent any
undue buckling of the housing.
E, and F, are bevel gear wheels, the gear wheel F, being shown broken away
in Fig. 2, so as to indicate the opening in the housing and the strengthening
flap D₁, referred to.
G, is a gear wheel shaft provided with ball bearing cones G¹. It is carried
in the bearing box H, which is preferably secured to the housing by the
bracket H¹.
Gare grooved rings which are screwed within the bearing box H, and which
constitute, with the cones G¹, a race-way for the balls g.
I, is a bevel gear wheel meshing with the bevel gear wheel F. This gear
wheel I, is screwed onto, or otherwise secured to the hollow mandrel K, and it
is provided with a shoulder i, formed on or secured thereto. This bevel gear
wheel I, is shown in dotted lines in Fig. 2.
J, is a grooved ring which is screwed into the housing and forms, with the
shoulder, a race-way for the balls 2, which carry one end of the hollow
3
017

page_text: mandrel K, and the bevel gear wheel I. The hollow mandrel K, is preferably
shaped as indicated in the drawings, and is provided with a shoulder or ball
bearing cone k, which, together with the grooved ring L, which is screwed into
the housing, forms a race-way for the balls 1, which help to carry the other
end of the hollow mandrel K.
M, is a ball bearing cup, which is screwed within the hollow mandrel K,
sleeved on the pedal shaft.
N, is a shouldered ring which is screwed into the ball bearing cup M, and
which is adjustable on the balls o, o¹.
O, is a grooved ring diaphragm separating the series of balls o, o¹, and makes
up with the ball bearing cup M, the cone A, and the shouldered ring N, a race-
way for the balls.
P, is a sprocket chain wheel, which is screwed on, or otherwise rigidly secured
to the mandrel K, which is sleeved on the pedal shaft.
Q, is a nut screwed onto the outer face of the threaded mandrel K, to hold
the sprocket chain wheel P, in place. There is a small grooved shoulder h,
formed on the housing, which, with the ball bearing cones A¹, on the pedal
shaft, makes a race-way for the balls p.
I have thus indicated a system of ball bearings which I consider preferable,
though other arrangements of the ball bearings for the several parts, may be
substituted without departing from the spirit of my invention. It will thus be
seen that I have provided a bicycle gear which is compact in form and which
may be capable of variation as to the gearing up or gearing down of the bicycle
by altering the proportions of the various gear wheels and parts. It is compact
in form and may be further protected from dust and dirt by a supplementary
casing. By utilizing this form of construction, great speed may be attained
without undue expenditure of power.
Dated this 9th day of September 1897.
BOULT & WADE,
Agents for the Applicant.
I, GEORGE THOMAS MARTIN, of the Town of Smith's Falls, in the County of
Lanark, and Province of Ontario, Canada, Architect, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
The object of the invention is to provide a bicycle gear which is compact in
form and simple in construction, whereby great speed may be imparted to the
sprocket chain wheel without undue expenditure of power, and it consists, essen-
tially, in mounting the sprocket chain wheel on a hollow mandrel which is sleeved
on the pedal shaft and connecting the hollow mandrel to the pedal shaft by
series of gear wheels, substantially as hereinafter described and then definitely
claimed.
Referring to the drawings filed with the Provisional Specification,
Figure 1, is a sectional elevation of my improved gear.
a
Figure 2, is a perspective view, partly broken away; the device being turned
end for end as compared with Fig. 1.
In the drawings, like letters of reference indicate corresponding parts in the
different figures.

page_text: In the several figures A, is a pedal shaft provided towards either end with the
ball bearing cones A¹, and shouldered preferably at a, a', so that the parts may
be held more securely.
C, is a bevel gear wheel which is screwed on, or otherwise fixed to the pedal
shaft near the end opposite to that on which the chain sprocket wheel is located.
D, is a housing, which is preferably cylindrical in form, as indicated in Figure 2,
and which is secured to the seat stem and diagonal brace of the bicycle frame in
the manner indicated. This housing D, has an aperture cut therein for the pur-
pose of permitting the gear wheel F, hereinafter referred to, to pass through,
and it is provided with the strengthening flap D', which serves to prevent any
undue buckling of the housing.
E, and F, are bevel gear wheels, the gear wheel F, being shown broken away
in Fig. 2, so as to indicate the opening in the housing and the strengthening
flap D referred to.
G, is a gear wheel shaft provided with ball bearing cones G¹. It is carried
in the bearing box H, which is preferably secured to the housing by the
bracket H¹.
Gare grooved rings which are screwed within the bearing box H, and which
constitute, with the cones G', a race way for the balls g.
I, is a bevel gear wheel meshing with the bevel gear wheel F. This gear
wheel I, is screwed onto, or otherwise secured to the hollow mandrel K, and it
is provided with a shoulder i, formed on or secured thereto. This bevel gear
wheel I, is shown in dotted lines in Fig. 2.
J, is a grooved ring which is screwed into the housing and forms, with the
shoulder, a race way for the balls, which carry one end of the hollow
mandrel K, and the bevel gear wheel I. The hollow mandrel K, is preferably
shaped as indicated in the drawings, and is provided with a shoulder or ball
bearing cone k, which, together with the grooved ring L, which is screwed into
the housing, forms a race way for the balls 1, which help to carry the other
end of the hollow mandrel K.
M, is a ball bearing cup, which is screwed within the hollow mandrel K,
sleeved on the pedal shaft.
N, is a shouldered ring which is screwed into the ball bearing cup M, and
which is adjustable on the balls o, o.
O, is a grooved ring diaphragm separating the series of balls o, o¹, and makes
up with the ball bearing cup N. the cone A¹. and the shouldered ring N, a race
way for the balls.
P, is a sprocket chain wheel, which is screwed on, or otherwise rigidly secured
to the mandrel K, which is sleeved on the pedal shaft.
Q, is a nut screwed onto the outer face of the threaded mandrel K, to hold
the sprocket chain wheel P, in place. There is a small grooved shoulder h,
formed on the housing, which, with the ball bearing cones A¹, on the pedal
shaft, makes a race way for the balls P.
I have thus indicated a system of ball bearings which I consider preferable,
though other arrangements of the ball bearings for the several parts, may be
substituted without departing from the spirit of my invention. It will thus be
seen that I have provided a bicycle gear which is compact in form and which
may be capable of variation as to the gearing up or gearing down of the bicycle
by altering the proportions of the various gear wheels and parts. It is compact
in form and may be further protected from dust and dirt by a supplementary
casing. By utilizing this form of construction, great speed may be attained
without undue expenditure of power.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In a device of the class specified, the combination with the pedal shaft,

page_text: of a hollow mandrel sleeved thereon; a sprocket chain wheel mounted on the
hollow mandrel and a series of gear wheels intermediate between the hollow
mandrel and the pedal shaft for conveying motion from the pedal shaft to the
sprocket chain wheel, substantially as specified.
2. In a device of the class specified, the combination with the pedal shaft A,
of the bevel gear wheel C, secured to the pedal shaft; the bevel gear wheel E,
meshing with the gear wheel C, and carried on one end of the shaft G, which
is suitably journalled; the bevel gear wheel F, carried on the other end of the
shaft G; the bevel gear wheel I, meshing with the bevel gear wheel F, and
secured to the hollow mandrel K; the hollow mandrel K, sleeved on the pedal
shaft A; and the sprocket chain wheel P, mounted on and secured to the hollow
mandrel, substantially as specified.
3. In a device of the class specified, the combination with the pedal shaft A,
journalled on ball bearings within the housing D, of the bevel gear wheel E,
meshing with the bevel gear wheel C, and carried on the shaft G, journulled
on ball bearings within the bearing box H, which is secured to the housing D,
the bevel gear wheel F, carried on the other end of the shaft G, and operating
through an opening cut in the housing D; the bevel gear wheel I, meshing
with the bevel gear wheel F, secured to the hollow mandrel K, and provided
with ball bearings; the hollow mandrel K, provided with ball bearings and
sleeved on the pedal shaft and the sprocket chain wheel P, mounted on and
secured to the hollow mandrel, substantially as specified.
4. In a device of the class specified, the combination with the pedal shaft A,
suitably journalled on ball bearings within the housing D; of the hollow
mandrel K, sleeved on the pedal shaft and provided with ball bearings, the
race ways for the balls being formed, by the shoulder i, on the bevel gear wheel I,
fixed to the mandrel K, and the grooved ring J, screwed within the housing;
by the shoulder k, formed in the hollow mandrel K, and the grooved ring L,
screwed within the housing D; and by the ball bearing cup M, screwed within
the mandrel, the shouldered ring N, screwed within the cup, the cone A¹
on the pedal shaft A, and the grooved ring diaphragm 0, separating the balls;
the sprocket chain wheel P, and a series of gear wheels intermediate between
the hollow mandrel and the pedal shaft, substantially as described and for the
purpose specified.
5. In a device of the class specified, the combination with the pedal shaft A,
suitably journalled; of the hollow mandrel K, sleeved on the pedal shaft A,
and provided with ball bearings, comprising the ball bearing cup M, screwed
within the mandrel K: the shouldered ring N, secured within the cup M; the
cone A¹, on the pedal shaft A; and the grooved ring diaphragm 0, separating the
balls, substantially as specified.
Dated this 7th day of June 1898.
BOULT & WADE.
Agents for the Applicant.