Improvements in Propelling Mechanism for Cycles.
Year: 1897

page_text: Date of Application 9th Mar., 1897
Complete Specification Left, 11th Oct., 1897-Accepted, 27th Nov., 1897
PROVISIONAL SPECIFICATION.
Improvements in Propelling Mechanism for Cycles.
I, GERARD BEEKMAN, of No. 5 East 34th Street, New York, County and State of
New York, United States of America, Gentleman, do hereby declare the nature of
this invention to be as follows :—
My inventon relates to means of changing the relative number of revolutions of
the driving and driven parts of a bicycle by varying the intervals of pressure of the
feet on the pedals so as to engage a friction clutch at each foot impulse and effect
propulsion or retardation on the principle set forth in the Specifications of my Letters
Patent No. 23619 of 1895, and No. 2513 of 1896.
My present invention consists in an improvement wherein the grip of the clutch
is male more effectual, or multplied in force, by certain novel features in the
construction of its mechanism, as hereinafter described.
Referring to the accompanying drawings, in which like characters of reference
indicate corresponding parts;
Figure 1, is a side elevation of a sprocket wheel and crank illustrating a form of
my invention in which the crank shaft is diametrically movable.
Figure 2, is a horizontal section taken at -x, Figure 1.
Figure 3, is a vertical section taken at y-y, Figure 2.
Figure 34, is an alternative form of the vertical section in Figure 3, showing the
flange 3, internally and externally fluted.
Figure 4, is a side view showing a modification of my invention in which the
crank shaft is on a fixed axis of rotation.
Figure 5, is a horizontal section taken at z-z, Figure 4.
Figure 6, is a vertical section taken at ¹¹, Figure 5.
Figure 7, is a detail view showing the crank and clutch collars in Figure 6 detached.
A, in the figures, represents the sprocket wheel of a cycle, which for purposes
and meaning herein, constitutes the "driven" part.
C, C, are the pedal cranks which together with the outer grip members H, H, and
the inner grip members G, G, Figures 1, 2, 3, and together with the external grip
members H1, H2, Figures 4, 5, 6, 7, for the purposes and meaning herein, constitute
the "driving" part.
The sprocket wheel A, in each arrangement, is mounted on a cylindrical shaft D,
rotating in ball bearings 2, 2, in the frame hanger E.
The cylindrical shaft D, has projecting annular flanges 3, 3, at each end which
receive the grip of the clutch. These flanges may be smooth, Figure 3, or to
promote grip, may be longitudinally fluted or corrugated, Figure 3^. For the
purpose of noiselessness and the prevention of frictional heat the adjacent frictional
surfaces of the flanges 3, 3, and of the grip members G and H, H, H2, are separated
by a series of washers of rawhide or leather 4, Figure 2, or by a cylinder of rawhide
or leather 4, Figures 5, 6. This rawhide or leather separating member may have a
toothed inner surface as shown in Figures 34, 5, and 6. The rawhide or leather

page_text: pedals are stationary or rotating at a different rate. The feet may rest on the
pedals which can remain idle while the bicycle is running, as for instance in
coasting, which does not involve the dangerous necessity of removing the feet
from the pedals. When force is exerted, the action of the grip members is of a
wrench-like character, affording immediately a very powerful hold, either for
propulsion or brake action, at the will of the rider, and the frequency of the impulses
can be made irrespective of the rate of speed, affording advantages in hill climbing
or varying grades or character of road, corresponding to those set forth in my
aforementioned patents.
The invention may be embodied in crank and chain propulsion as illustrated, or it
may be embodied in crank propulsion having the cranks applied directly to the shaft
of the traction wheel.
Improvements in Propelling Mechanism for Cycles.
I, GERARD BEEKMAN, of No. 5 East 34th Street, New York, County and State of
New York, United States of America, Gentleman, 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 to means of changing the relative number of revolutions of
the driving and driven parts of a bicycle by varying the intervals of pressure of the
feet on the pedals so as to engage a friction clutch at each foot impulse and effect
propulsion or retardation on the principle set forth in my previous Letters Patent
No. 23619 of 1895 and No. 2513 of 1896.
My present invention consists in an improvement wherein the grip of the clutch
is made more effectual, or multiplied in force, by certain novel features in the
construction of its mechanism, as hereinafter described and claimed.
Referring to the drawings filed with my Provisional Specification, in which like
characters of reference indicate corresponding parts:
Figure 1 is a side elevation of a sprocket wheel and crank illustrating a form of
my invention in which the crank shaft is diametrically movable. Fig. 2 is a
horizontal section taken at x-x Fig. 1. Fig. 3 is a vertical section taken at y—y
Fig. 2. Fig. 3ª is an alternative form of the vertical section in Fig. 3 showing the
flange 3 internally and externally fluted.
Fig. 4 is a side view showing a modification of my invention in which the crank
shaft is on a fixed axis of rotation. Fig. 5 is a horizontal section taken at z-z Fig. 4.
Fig. 6 is a vertical section taken at ¹ Fig. 5. Fig. 7 is a detail view showing
the crank and clutch collars in Figure 6 detached.
A, in the figures, represents the sprocket wheel of a cycle, which for purposes and
meaning herein, constitutes the "driven " part.
C, C are the pedal cranks which together with the outer grip members H, H, and
the inner grip members, G, G Figs. 1, 2, 3, and together with the external grip
members H1, H2, Figs. 4, 5, 6, 7, for the purposes and meaning herein, constitute
the "driving" part.
The sprocket wheel A, in each arrangement, is mounted on a cylindrical shaft D,
rotating in ball bearings 2, 2, in the frame hanger E.
The cylindrical shaft D, has projecting annular flanges 3, 3, at each end which
receive the grip of the clutch. These flanges may be smooth, Fig. 3, or to promote

page_text: The effect of the construction shown is to produce spring-like cranks having a very
limited range of elastic flexure. The grip members are closely fitted so that no
unnecessary lost motion occurs, and the springs 10, are of such tension and power as
to avoid any looseness of the pedal cranks.
In operation, the device in its normal condition, and under the mere weight of the
legs of the rider, will allow the driven part (D, A,) to revolve freely while the pedals
are stationary or rotating at a different rate. The feet may rest on the pedals
which can remain idle while the bicycle is running, as for instance in coasting,
which does not involve the dangerous necessity of removing the feet from the
pedals. When force is exerted, the action of the grip members of a wrench-like
character, affording immediately a very powerful hold, either for propulsion or
brake action, at the will of the rider, and the frequency of the impulses can be made
irrespective of the rate of speed, affording advantages in hill climbing or varying
grades or character of road, corresponding to those set forth in my aforementioned
patents.
The invention may be embodied in crank and chain propulsion as illustrated, or it
may be embodied in crank propulsion having the cranks applied directly to the shaft
of the traction wheel.
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. Propelling mechanism for cycles arranged and operating substantially as
herein before described.
2. Propelling-mechanism for cycles in which the driving part comprises two
cranks normally projecting in opposite directions from the axis of rotation of the
driving part as a whole, is normally disengaged from the driven part, but can be
engaged therewith through clutch mechanism by slight differential rotation of the
two cranks relatively to the driven part, substantially as described.
3. Propelling-mechanism for cycles in which the driving part comprises a rotary
crank that is mounted to turn slightly both in a forward and backward direction
about an axis non-coincident with that of the driving part as a whole, and is
provided with two annular grip-members, and in which the driving part is that are
normally disengaged from and are concentric with the driven part but can be engaged
therewith by a slight rotation relatively to such driven part and in either direction
of the crank about its eccentric axis, which causes the annular grip-members to
move in opposite directions and act on the driven part, substantially as described.
4. Propelling-mechanism for cycles in which the driving part comprises two
rotary pedal cranks normally projecting in opposite directions from the axis of
rotation of the driving part as a whole, is normally disengaged from the driven part,
but can be engaged therewith by a slight differential rotation relatively thereto of
the two cranks, and in which the two cranks are mounted to turn slightly in either
a forward or backward direction about eccentric axes rigidly connected together and
are provided with springs tending to maintain them in, or to restore them to, their
normal oppositely directed positions, substantially as described.
5. In propelling mechanism for a cycle, the combination with a rotary driven
member of clutch mechanism mounted thereon and adapted to engage therewith,
rotary crank supports having pedal cranks flexibly mounted thereon and engaging
with the clutch mechanism so as to actuate the same by the flexure of the said
cranks, elastic means tending to resist flexure of the cranks in either direction and
to support each crank at an intermediate position of flexure and connecting means
extending through the axis of rotation of the crank supports and rigidly connecting
the said supports together so as to maintain the cranks in substantially opposite
relation, substantially as described.
6. Propelling-mechanism for cycles constructed, arranged, and operating
substantially as hereinbefore described with reference to and shown in Figs. 1, 2 and 3
and as modified according to Fig. 3ª of the drawings.