Transmitting Mechanism for Cycles.
Year: 1895

page_text: Date of Application, 10th Dec., 1895-Accepted, 15th Feb., 1896
COMPLETE SPECIFICATION.
Transmitting Mechanism for Cycles.
I, GERARD BEEKMAN, of No. 5 East 34th Street, New York City, County and
State of New York, United States of America, Gentleman, do hereby declare the
nature of my invention, 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 means for varying the relative rate of rotation between
the treadle shaft and the driven wheel of a cycle, and the same consists in certain
novel combinations of mechanical elements hereinafter fully described and claimed.
Referring to the accompanying drawings;
Figure 1, represents a side view of the frame of a "safety" bicycle, showing my
invention applied thereto;
Figure 2, a detail perspective view of certain operating parts;
Figure 3, an enlarged sectional view taken on the line, Figure 1 ;
Figure 4, a cross-section at y-y, Figure 3;
Figure 5, a detail view of one of the leather friction disks;
Figures and 7, detail views of the extremities of the bearing yokes in
Figure 3;
Figure 8, a detail view of one of the ball bearing cups on the outer yoke in
Figure 3.
Figure 9, a detail view of one of the ball bearing cones on the inner yoke in
Figure 3.
In Figure 3, 1 represents the driving or pedal shaft ; 2, the pedals, and 3 the
sprocket wheel approximately concentric with said shaft but independently
rotative.
The sprocket wheel 3, is supported by ball bearings, 4 upon a ridged yoke 5,
forming a continuation of the tube 6, of the frame (see Figure 1).
The pedal shaft 1, is supported by ball bearings 7, upon a movable yoke 8,
pivoted at 9. Means are provided for operating the yoke 8, at the will of the
rider, consisting in three rods 10, 10 11, forked bell crank 12, and hand lever 13,
having a pawl and ratchet 14, whereby it is set, (see Figure 1).
The sprocket wheel 3 bears a cylinder or drum 15, and the pedal shaft bears a
cylinder 16 composed preferably of leather washers fitting the feather 17 on the
pedal shaft 1, to prevent them from rotative displacement. Any other suitable
material may be used to compose the friction cylinder 16.
Means are provided for maintaining parallelism between the friction cylinder 16,
and the friction drum 15, irrespective of the alternating foot pressure of the rider
at the opposite ends of the pedal shaft I, consisting in the elongated pivotal support
of the yoke 8, at 9, in the rigid frame of the machine.
When the pedals 2, are depressed by the feet of the rider, the cylinder 16, which
fits loosely within the interior cylinder surface of the drum 15, naturally engages
therewith with friction and the pedals 2, thereby impart motion to the sprocket
wheel 3, chain 21, rear sprocket wheel 22, and the driven wheel of the bicycle.
When it is desired to counter the pressure of the feet and reduce the frictional
engagement of the cylinder 15, with the drum 16, the lever 13, is set forward,
lifting the yoke 8, and pedal shaft slightly with it. When this is done a certain
amount of slip is permitted between the cylinder 16, and drum 15.
By entirely countering the pressure of the feet by the lever 13, the cycle may be
used for coasting without removing the feet from the pedals; the latter remaining.
stationary.

page_text: The lever 13 may again be used by pulling the same backward, to co-operate
with the pressure of the feet for the purpose of increasing the pressure of the
cylinder 16 against the dram 15, and moreover with this movement, the lever 13,
may be operated as a brake lever when the rider holds his pedals 2, stationary
with his feet while the machine is running with momentum; the friction between
the revolving drum 15, and the now stationary cylinder 16, serving to retard the
machine.
In matter of detail, the leather washers 16, composing the cylinder, are clamped
together by nuts 25, by the compression of which the diametrical expansion of the
body of leather may be slightly varied, and within the drum 15, there are inserted
longitudinal strips 26, Figure 4, which lie in inclined positions approaching
tangents, disposed in opposition to the direction in which the cylinder 16, rotates
when the machine is moving forward, and these strips thereby engage with increased
effectiveness of friction with the peripheries of the leather disks.
The frictional engagement of the cylinder and drum may also be varied by
adjusting the screws 27 against the split bushing 28 that forms a backing for the
strips 26.
Bearing cones 30 are provided to the pedal shaft 1, and bearing cups 31 therefor
are removably attached by screws 32 to the movable outer yoke 8. The drum 15,
contains bearing cups 33 for supporting the sprocket wheel 3, and the bearing
cones 34 therefor are removably attached by screws 35 to the fixed inner yoke 5.
The extremities of the yokes are left open at 37, 38 as in Figures 6 and 7 to
facilitate separating the parts.
The operating rods 10, 10, are attached to the movable yoke 8, at the ears 4),
and the frame rods 41, Figure 1, are attached to the fixed yoke 5, at 42.
It is to be understood that my invention is not limited to the construction shown
wherein the concave cylindric surface embodied in the drum 15, is attached to the
driven part and the convex cylindric surface embodied in the cylinder 16, is attached
to the driving part; whereas; said relation of attachment may be reversed, and
moreover the construction of the cylindrically surfaced parts may be greatly varied,
or even substituted by conic or other tapering surfaces; the essential feature
consisting in that the frictional engagement of such surfaces, the one with the
other, shall vary with the variation in the relative positions of the respective axes
of rotation of the engaging parts.
My invention is of course applicable to other forms of cycles than that shown.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, 1 declare that what
I claim is :-
1. In a cycle, the combination of a pedal and its shaft; a wheel or part to be
driven by said shaft, and unattached thereto; and a two-part friction device the
members of which are secured respectively to said shaft and driven part, and are
movable diametrically with relation to each other, whereby a varied pressure
upon the pedal by the foot of the rider, will produce a correspondingly varied
degree of rotation of said driven part, substantially as set forth.
2. In a cycle, the combination of a pedal, and its shaft, the latter furnished with
an attached friction-member having a cylindrical surface; and a non-attached
wheel cr driven part provided with a hollow cylindrical friction-member which
approximately fits the friction member on the shaft, the said shaft and driven part
being diametrically movable with relation to each other, whereby a varied pressure
upon the pedal by the foot of the rider, will vary the degree of rotation of said
driven part, substantially as set forth.
3. In a rear-driven bicycle, the combination of a sprocket wheel journalled on a
stationary part or frame of the machine, and having a friction drum; a pedal and
its shaft, the latter journalled in a part or frame which is movable with relation to
said wheel support, the said shaft being furnished with a cylindrical friction-member
approximately fitting within said drum, whereby a varied pressure upon the pedal

page_text: by the foot of the rider, will vary the degree of rotation of the sprocket wheel,.
substantially as set forth.
4. In a rear-driven bicycle, the combination of a sprocket wheel, having an
attached friction drum; a fixed yoke, supporting said wheel, a pedal and its shaft ;.
a friction cylinder secured to the shaft and approximately fitting within the drum ;.
and a supporting yoke for said shaft, which yoke is mounted to swing with relation
to said fixed yoke, to allow a variably close engagement between the friction
drum and cylinder to be affected by a varied pressure upon the pedal, substantially
as set forth.
5. In a cycle, the combination of a pedal and its shaft; a wheel or part to be
driven by said shaft, and unattached thereto, and a two-part friction device the
members of which are secured respectively to said shaft and driven part, and are
movable diamet.ically with relation to each other, whereby a varied pressure upon
the pedal by the foot of the rider, will produce a correspondingly varied degree of
rotation of said driven part, and co-operating therewith a hand operated mechanism
attached to the frame of the machine suitably connected to control the relative.
diametric movement of said members, and partially or wholly counteract or augment
the frictional transmitting effect of the foot pressure by the independent action of the-
hands of the rider.
Dated this 9th day of December 1895.
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62 St. Vincent Street, Glasgow, Agents for the Applicant..