Improvements in Bicycles.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Bicycles.
I, JOHN BENJAMIN EVANS, a citizen of the United States, residing at
28 Wyoming Street, in the City of Philadelphia, County of Philadelphia, State
of Pennsylvania, United States of America, Mechanic, 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 generally although not restrictively to a class of bicycles
known as "safeties," consisting, as is well known, of a front wheel, a rear or
driving wheel, a main frame, and a crank axle equipped with pedals supported in
the main frame and connected with the driving wheel.
Generally stated, it is the object of my invention to utilize a toothed gearing as
opposed to a sprocket chain gearing as the power transmitting medium between the
crank axle and the driving wheel, and further to so arrange or apply a toothed
gearing that it may be set to apply the rotation imparted to the pedals to speed or
power at will.
In the drawings I show and herein I describe a good form of a convenient
embodiment of my invention, the particular subject-matter claimed as novel being
hereinafter definitely specified.
In the drawings,
Figure 1 is a view in side elevation of a bicycle embodying a preferred form of
my invention.
Figure 2 is a sectional plan on the line - of Figure 1.
Figure 3 is a view in detail of the clutch.
In the drawings, A is the front or steering wheel, 13 the driving wheel, C the
main frame, D the saddle, E the handle bar, F the crank axle, and the pedals,
of the bicycle represented.
The crank axle is equipped with two clutch faced bevel gear wheels G G*
mounted and adapted to run free upon the respective extremities of the crank axle.
The clutch faces of said wheels are arranged upon the inner faces of their hubs,
and the gear or peripheral teeth of said wheels also preferably face inwardly.
g is a clutch mounted upon and keyed to the central portion of the crank axle,
and adapted to be thrown into engagement with either of said bevel gear wheels at
will, and thereby to lock the wheel so engaged fast to the axle and compel its
rotation therewith. Said clutch is, however, also adapted to occupy a position
intermediate between, and out of engagement with both of, said bevel' gear wheels.
Any convenient means may be employed to throw the clutch. I prefer, however,
to employ the arrangement shown in the drawings, which consists of a bell crank
lever, mounted upon a bracket or extension c of the main frame, one arm of which, h,
is forked, and each branch of the fork equipped with a stud, which studs exist on
diametrically opposite sides of the clutch and are entered in a common transverse
groove or stud way formed in said clutch g, and the other arm of which, h', is
engaged with a pitman ², the upper end of which is connected to one arm of a
second bell crank lever ³ pivoted to the front portion of the main frame, to the
other arm of which is secured the lower end of a second and vertical pitman /*
which is operatively engaged with a lever handle mounted in connection with
the handle bar. 11 are a pair of toothed wheels mounted upon the respective
extremities of the axle of the driving wheel.
J.J are a pair of compound gear wheels each of which has a double set of
teeth, namely, a set of ordinary straight gear teeth and a set of bevel teeth, or
teeth the faces of which are inclined to the axes of the wheels. In both said
wheels the bevel teeth are formed on the side faces of the wheels at some radial

page_text: distance inward from the peripheries thereof, while the straight teeth exist on the
peripheries of said wheels.
K is a shaft equipped at its front end with a bevel pinion. K* and at its rear end
with a bevel pinion K', which shaft is supported by means of suitable brackets or
supports, erected from the main frame, in such position that its pinion K* is in
constant engagement with the bevel wheel Grand its-pinion K' in constant engage-
ment with the bevel teeth of the wheel J.
Lis a corresponding shaft, equipped at its front end with a bevel pinion L*, and
at its rear end with a bevel pinion L, and supported, by means of suitable brackets
or supports erected from the main frame, in such position that its pinion L* is in
constant engagement with the wheel G and its pinion L' in constant engagement
with the teeth of the wheel J*.
The straight teeth of the compound wheels J J* are engaged with the teeth of
the wheels I* respectively.
It will now be understood that the bevel wheel G is in mesh with a pinion on the
front end of a shaft K, the rear end of which is provided with a pinion in engage-
ment either directly or through the intervention of a compound or multiplying
wheel with the axle of the driving wheel, and that the bevel wheel G* is
connected with said driving wheel axle by a corresponding train of gearing.
The corresponding wheels and shafts of the two trains of gearing, with the
exception of the wheels J and J×x are preferably of equal size, but said wheel Jis
preferably made of considerably greater diameter than the wheel J, so that a
greater amount of rotation of the crank axle is required to produce a rotation of
the driving wheel when transmitted through the gearing on one side of the machine
than when transmitted through the gearing on the other side of the machinë.
In the operation of the bicycle the clutch is thrown into engagement with one of
the free bevel wheels on the crank axle, thereby said wheel is locked to and
compelled to rotate with said axle, and the motion of the axle is transmitted
through the train of gearing of which said wheel forms a part, to the driving wheel,
whereby the propulsion of the machine is occasioned. In the arrangement shown,
the rotation of the driving wheel through the train of gearing thrown into operation
as described, will occasion the, so to speak, reversed operation of the other or
second train of gearing, but such rotation will be idle and without effect upon the
machine because the crank axle bevel wheel of said second train runs freely upon
the crank axle.
My invention provides a strong, rigid, positive, gearing between the crank axle
and the driving wheel, which gearing reduces the lost motion to a minimum, is
strong and certain in action, and, as explained, can be applied to either speed or
power at will. It is, of course, obvious that the toothed gearing may be composed
or built
up of any desired arrangement of toothed wheels or shafts, that it permits
of any desired multiplication of the rotation of the crank axle, and that it may be
employed in connection with any preferred type of wheel.
The various wheels and devices composing the gearing described may of course
be applied in connection with ball bearings disposed in a suitable arrangement to
facilitate their rotation and utilize the motion imparted to the pedals in the most
advantageous manner.
The shafts K and L are especially advantageous in the use of a positive or solid
toothed connecting gearing between the crank axle and driving wheel, combining
as they do great rigidity and certainty of operation, with the minimum of weight.
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:
.:47JZ
1. In a bicycle, in combination with a driving wheel, a crank axle, and a train
of toothed gearing connecting said crank axle and said driving wheel, substantially
as set forth.
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2. In a bicycle, in combination with a driving wheel, a crank axle, means.for

page_text: transmitting the rotation of said crank axle to the driving wheel, consisting of a
train of toothed gearing, a second train of gearing between said crank axle and
said driving wheel, and means for throwing one or the other of said train of gearing.
at will into operation, substantially as set forth.
3. In a bicycle, in combination, a driving wheel, a crank axle, means for trans-
mitting the rotation of said crank axle to the driving wheel, consisting of a train of
toothed gearing, a second train of gearing between said crank axle and said driving
wheel, one of said trains of gearing being proportioned for speed and the other for
power, and means for throwing said trains of gearing alternately into operation,
substantially as set forth.
4. In a bicycle, in combination, a driving wheel, a crank axle, a double train of
toothed gearing connecting said crank axle with said driving wheel, a clutch, and
means for throwing said clutch, substantially as set forth.
5. In a bicycle, in combination, a driving wheel, a crank axle, a pair of clutch
faced toothed wheels mounted to run on said crank axle, a clutch mounted on and
keyed to said crank axle, means for throwing said clutch into alternate engagement
with said toothed wheels, the shafts K and L with their bevel pinions, the compound
wheels J and J*, and the wheels I and I*, all mounted and arranged substantially
as set forth.
6. In a bicycle, in combination, the driving wheel connected with which is the
toothed wheel I, the crauk axle, the bevel wheel G mounted on the crank axle, the
compound wheel J provided with peripheral and bevel teeth, the peripheral teeth
of which are in mesh with the teeth I, and the shaft K the extremities of which
are provided with bevel pinions respectively in mesh with the bevel wheel G and
the bevel teeth of the compound wheel J, substantially as set forth.
Dated this 12th day of December A.D. 1891.