Improvements in Propelling and Braking Mechanism for Cycles.
Year: 1897

page_text: Date of Application, 26th Oct., 1897-Accepted, 2nd July, 1898
COMPLETE SPECIFICATION.
Improvements in Propelling and Braking Mechanism for Cycles.
I GERARD BEEKMAN, Gentleman, of No. 47, Cedar Street, New York, County and
State of New York, United States of America, 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:-
My invention relates to improvements in bicycle propelling and braking
mechanism operated by simultaneous depression of two opposite rotary pedal
cranks; the rotary motion of the cranks being imparted to the sprocket wheel or
other driven element by frictional engagement determined by foot pressure. A
clutch action is produced intermittently by the pressure or impulses of the rider's
feet upon the pedals, and forward or backward propulsion, or braking, or coasting,
may each be effected according to the manner of moving or arresting the pedal
cranks, and without requiring the feet to be removed from them. By a reduction
or release of foot pressure the pedals may remain stationary or be revolved at a
slower speed than the revolution of the sprocket wheel or driven element, and the
propelling impulses may be exerted at such intervals as desired, permitting the
rider to rest or dwell between impulses at will, and he may thereby use a com-
paratively "low gear" giving advantage in hill climbing while not imposing a
continuous and tedious rapidity of revolution of the cranks when speeding rapidly
on level or descending roads.
The principal feature of my invention consists in a friction clutch or brake
actuated to engage longitudinally with the driven shaft by a limited elastic rotative
movement of the opposite cranks with respect to each other in either rotative
direction so that the device may be used as a brake by the retardation of whichever
pedal happens at the moment to be rearmost and rising in its orbit of rotation;
and the friction device is also capable of use as a propelling clutch of itself, but
a part of my invention consists in its conjunctive use with a positive clutch for
forward propulsion; and my invention also consists in certain novel features of
construction; all as more fully hereinafter described and defined in the appended
claims:
Referring to the drawings:
Figure 1, represents a cross-section in the frame of a bicycle taken in the length
of the crank shaft hanger at y-y, Figure 2, and showing the internal construction
of the parts. Figure 2 is a vertical section taken at -, Figure 1. Figure 3
is a detail view of the crank shaft clutch portions in side elevation. Figure 4 is
an end view of Figure 3 partly in section. Figure 5 is a side view of one of the
crank hubs and a portion of the shaft integral therewith.
The crank A, A, have their hubs 1, 2, and integral shaft portions, 3, 4, securely
fixed into the clutch parts 5, 6, by means of tongues and mortises 30, 31, forming
relatively movable shaft sections B, B¹, and both said sections revolve together
except for a slight yielding motion rotatively with respect to one another which
is converted into longitudinal motion, limited by the contact of the faces 5, 6, of
said sections with the rigidly coupled concave clutch portions 7, 8, respectively of
the driven element or shaft C, of the sprocket wheel D. The part C, is mounted

page_text: on ball bearings 9, 10, and the crank shaft B, B', is journaled at its extremities 3, 4,
in the extremities of the said shaft C. When the cranks A, A', are propelling, the
parts B, B¹, revolve with the part C, and the ball bearings 9, 10, therefore serve
for the crank shaft B, B. By thus making the cranks A, A¹, and their hubs 1, 2,
separable from the clutch parts 5, 6, these clutch parts may in case of wear be easily
replaced.
The slight rotative movement of the shaft sections B, B', with respect to one
another (in response to the simultaneous depression of the pedals of the opposite
cranks A, A¹) is converted into a longitudinal movement by the expanding action
of the interposed pieces 14, which tilt in the opposite recesses 11, 12, in the manner
indicated by dotted lines in Figure 3, and such action is opposed by a spring
arrangement consisting of a compression spring such as E, confined under pressure
between the shoulder 42 of one of the shaft sections B and the extremity 18; of
the screw-threaded tie-rod 17, which is adjustably connected to the other shaft
section B. When at rest the resistance of the compression spring is taken up on
the pieces 14, in order that the pedals when relieved from pressure may readily
return to their normal position. The spring may be adjusted by means of the
nut 16, and jam nut 19, with sufficient force to resist the weight of the rider's feet
on the pedals; it being intended that the frictional clutch device shall engage only
when depression is effected by transferring the weight of the rider's body more or
less from the saddle to the pedals assisted in emergency by muscular effort.
The relative limited rotative movement of the shaft sections B, B1, under the
longitudinal pressure of the spring may be comparatively relieved from friction by
the interposition of ball bearings such as F, in Figure 1. The bearing cone 40,
slides upon the tie rod 17, and the bearing cup 41, rests against the shoulder 42, in
the shaft section B'.
In addition to the friction clutch device 5, 7, and G, S, I prefer to also employ a
positive clutch for forward propulsion, consisting of rollers 20, arranged in inclined
pockets 21, which for the purpose of concentration are located in the surfaces, 5, 6,
of the clutch sections; said rollers having sufficient weight to engage through
gravity without lost motion on either surface 7, 8, of the part C, when the
crank A, or A', is forwardly propelled. The power of the device as a brake can
be determined by varying the angle of construction of the conical friction
surfaces 5, 6, 7, 8, and the formation of the recesses 11, 12, and piece 14..
In the operation of the device, the driving element consisting of parts A, B,.
A, B, is normally disengaged rotatively from the driven element C, D). In order
to start the bicycle forwardly, foot pressure is applied to the pedal of the forward-
most crank and the roller clutch 20 at once engages with the sprocket wheel hub
or shaft C, and drives the machine. When headway is obtained, the rider may
relax his foot effort at pleasure between strokes, exerting a thrust as occasion
requires, and thereby avoid continuous rapid motion of the feet when running
at high speed on level roads, or under other conditions requiring moderate effort
to keep the machine in motion at the desired speed. In order to coast or allow
the bicycle to run for a distance by its momentum, the pedals may be brought to
rest; the shaft B, B', remaining idle within the revolving hollow shaft or hub C,
and the spring E, supporting the weight of the feet through the agency of the
expanding devices described, affording a comfortable foot rest without necessitating
the removal of the feet from the pedals. Whenever it is desired to moderate or
check the speed of the wheel, the weight of the rider may be more or less trans-
ferred from the saddle to the pedals simultaneously rotating the cranks A, A', and.
their respective shaft sections B, B¹, in opposite directions to the slight extent
limited by the impingement of the clutch surfaces 5, 7 and 6, 8, applying the desired
degree of frictional retardation to the revolving part C. An emergency stop may
be effected in like manner by a vigorous depression of the pedals produced by a
combination of the weight of the rider and muscular effort. Braking thus takes
the place of back pedaling as ordinarily understood. The cycle may also be pro-
pelled without a complete revolution of the pedal and for exhibition purposes, etc.,

page_text: may be propelled backwards by simultaneously depressing both pedals and applying
the excess of pressure to the rear pedal. In other words entire control and manage-
ment of the machine is obtained by the action of the feet on the pedals above
described. The use of gravity as a substitute for the muscular effort of back pedal-
ing as ordinarily practised and the relief from the necessity of following the motion
of the machine on the pedals when propulsion is not required makes the device a
labor saver.
The mechanism thus described is concentrated within the crank shaft hanger
box G, preserving the conventional form of the bicycle frame.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In a cycle, the combination with a suitable supporting frame and a rotary
driven element mounted therein, of two oppositely disposed pedal cranks mounted
within said driven element upon shaft sections having a limited rotative and longi-
tudinal movement relative to each other, mechanism for converting the opposed
rotative movement of said shaft sections in either relative direction from a normal
intermediate position into an opposed longitudinal movement thereof in one given
direction, and frictional contact portions or surfaces upon said shaft sections adapted
to engage with frictional contact surfaces upon said driven element by said opposed
longitudinal movement of the sections, and elastic means tending to resist said
opposed movements and to maintain the cranks in their normal opposite relation
2. In a cycle, the combination with a crank shaft hanger box having ball bear-
ings at each extremity, of a driven shaft rotative in said bearings and carrying a
sprocket wheel or other motion transmitting device located beyond the extremity
of the hanger box, and two cranks immediately outside the extremities of the
driven shaft and having a limited rotative movement with relation to each other,
clutch mechanism located between said ball bearings and enclosed within said
hanger box, and means whereby said clutch mechanism is engaged and disengaged
with the driven shaft by the said relative movement of the cranks to communicate
motion from the driving to the driven shaft.
3. In a cycle, the combination with a crank hanger and a rotary tubular driven
shaft therein, of two oppositely disposed pedal cranks mounted upon shaft sections
extending within the tubular shaft and having a limited rotative and longitudinal
movement relative to each other, mechanism for converting the opposed rotative
movement of said shaft sections in either relative direction from a normal inter-
mediate position into an opposed longitudinal movement thereof in one 'given
direction located between the adjacent inner ends of said shaft sections, tapered
frictional contact surfaces upon said shaft sections caused to engage with tapered
frictional contact surfaces within said driven shaft by said opposed longitudinal
movement of the sections, and springs and means for confining them with inward
longitudinal pressure against said shaft sections.
4. In a cycle, the combination with a crank hanger and a rotary tubular driven
shaft therein, of two oppositely disposed pedal cranks mounted upon shaft sections
extending within the tubular shaft and having a limited rotative and longitudinal
movement relative to each other, mechanism for converting the opposed rotative
movement of said shaft sections in either relative direction from a normal inter-
mediate position into an opposed longitudinal movement thereof in one given direc-
tion located between the adjacent ends of said shaft sections, tapered frictional contact
surfaces upon said shaft sections caused to engage with tapered frictional contact sur-
faces within said driven shaft by said opposed longitudinal movement of the sections,
and a spring and means for confining the same with longitudinal pressure against
said shaft sections, and a positive clutch mechanism consisting in rollers located in
inclined pockets and interposed between said sections and said driven shaft adapted
to engage for a given direction of rotation.
5. In a cycle, the combination with a friction clutch having its members

page_text: respectively connected with the driving and driven elements, of a positive clutch
consisting in rollers or balls arranged to act in seats inclined in a given direction
with reference to rotation and located between the friction faces of the said clutch.
6. In a cycle, the combination with a friction clutch having its members'
respectively connected with the driving and driven elements, of rotary pedal
cranks having a limited relative movement to actuate said clutch, a spring tending
to maintain said cranks in opposite positions and means for.rendering said spring
so operative by pressure in opposite directions upon the crank hubs, and a roller
or ball bearing surrounding said axis and interposed to receive the pressure of
said spring and relieve the cranks from friction in their said relative movement.
7. In a cycle, the combination with a crank shaft hanger of a clutch mechanism
contained within said hanger for engaging the driving and
elements, consisting in a hollow rotary driven member, having inwardly facing
tapered friction shoulders, and a drive shaft having two longitudinally movable
hollow sections provided with outwardly facing tapered friction shoulders and
with formations adapted to separate said sections by a rotary movement with
respect to one another, pedal cranks removably connected with said sections, and a
cross-tie bolt, and an adjustable spring or springs thereon interposed between the
shoulders of said bolt and said sections bearing inwardly upon the crank hubs
tending to press them together, and release the frictional contact of said shoulders;
said cross-tie bolt adapted simultaneously to secure in position said pedal cranks
and sections and adjust the tension of said spring or springs.
Dated this 26th day of October 1897.
driven
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.