Improvements in and relating to Cranks for Velocipedes, Bicycles, and the like.
Year: 1898

page_text: Date of Application, 9th May, 1898-Accepted, 3rd Sept., 1898
COMPLETE SPECIFICATION.
Improvements in and relating to Cranks for Velocipedes, Bicycles,
and the like.
I, WALTER JAY BARRON, of No. 461, Bedford Avenue, in the Borough of
Brooklyn, County of Kings, and City and State of New York, in the United
States of America, Inventor, do hereby declare the nature of this said 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 crank and pedal mechanisms for velocipedes, bicycles
and other vehicles intended for foot propulsion, and has for its main object to
provide a construction of such character that at the will of the rider the length
of the crank or the leverage of the crank mechanism may be increased varying
amounts by simple foot movements of the rider, thus reducing the power neces-
sary to propel the machine and rendering the mechanism peculiarly adapted for
hill climbing or like up-grade work.
My invention consists primarily in combining with the main crank an auxiliary
pedal-carrying crank in such manner that the auxiliary crank to which the power
is applied shall be locked to or rigidly connected with the main crank in one
direction of rotation of the auxiliary crank, so that the two cranks travel together,
but which shall be free to turn independently of the main crank in the opposite
or backward direction of rotation of the auxiliary crank, and in various other
features of construction and combinations of devices all of which will be herein-
after more fully described and particularly pointed out in the appended claims.
In the accompanying drawings:-
Figure 1 shows a portion of the crank axle of a bicycle or other foot-propelled
machine and a crank and pedal mechanism, embodying my improvements, part
of the view being broken away or made in section to more clearly exhibit the
mode of connecting the auxiliary crank arm to the main crank arm.
Figure 2 is an elevation of the auxiliary crank arm detached and with the
pedal and cap plate removed and looking at the contrivance from the right-hand
side of Figure 1.
Figure 3 is a view similar to Figure 2, but looking at the contrivance from the
left-hand side.
Figure 4 is a perspective view of the combined clutch plate, bearing and
screw.
Figure 5 is a view of the cover plate; and
Figure 6 is a diagrammatic view illustrating the mode of operation of the
mechanism.
In the various views the same part will be found designated by the same
numeral of reference.
1 designates the crank shaft of a bicycle, velocipede, or other similar machine
and 2 the main driving crank, which in this instance is shown as attached to one
end of the shaft by a bolt and nut 3, but said crank of course may either be
formed integral with said shaft or may be otherwise secured thereto. At the
DQ71

page_text: other end of the crank shaft is another crank oppositely disposed as usual, but
not shown.
At the free end of each main crank 2 is connected an auxiliary crank or arm 4
having at its free end a pedal shaft or axle 5, upon which is mounted, as usual,
a pedal or foot rest 6, which may be mounted on ball bearings indicated at 7,
as customary, so that the pedal is free to revolve in both directions on said axle 5.
The main crank arm and the auxiliary crank arm are connected together by
the following means. At the free end of the arm 2 is formed transversely a
threaded perforation 8 into which is screwed the threaded portion 9 of a bolt or
screw, which is formed or provided at its opposite end with a circular clutch
plate 10 and intermediately with a cylindrical bearing or support 11 for the
hub 12 of the auxiliary crank arm 4. Preferably the screw 9, the clutch plate 10
and the bearing 11 are all formed out of a single piece of metal. The clutch plate
is seated in a circular recess or depression 13 on the outer side of the hub of the
auxiliary crank arm 4, and said plate is formed at any desired number of points
with notches or cutaways 14 for the reception of balls or rollers 15, the said
notches or cutaways being wider at one end than at the other or being formed
of gradually tapering width. The balls or rollers bear at the bottoms or cam
portions of the notches and on the inner face of the circular seat or recess 13
formed in the auxiliary crank arm. Preferably in each notch or cutaway is a
small spiral spring 16 for pressing or holding the ball or roller towards the
narrower end of the slot or notch, but these springs may be omitted, although
they are desirable, since they insure a more prompt action of the clutch mechan-
ism. A cap or cover plate 17 is provided primarily to keep the balls or rollers
and springs in place and to exclude dirt and dust, and this plate may be held in
position by a screw 18 passing through a central perforation 19 in the plate and
into a threaded hole 20 in the clutch plate 10.
It will be observed from the foregoing and from the drawings that the
auxiliary crank arm bearing the freely revoluble pedal is arranged to turn
rigidly with the main crank arm 2 in a forward direction and to turn indepen-
dently thereof in a backward direction. When the auxiliary crank arm 4 is
turned forwardly, or when pressure is applied to it to turn it in the direction of
the arrow at Figure 2, the hub of the auxiliary crank arm tends to drive the balls
or rollers in the same direction towards the narrower ends of their slots but
before the said balls or rollers can be moved to the extremities of their slots they
take firm bearings between the inner side of the hub and the bottoms of their
slots and operate to rigidly connect the auxiliary crank arm with the clutch
plate or with the main crank arm, of which the clutch plate forms a part, and
thus by means of the clutch mechanism the auxiliary crank arm and the main
crank arm are so connected together that when pressure is applied in the direction
of the arrow at Figure 2 they are or become rigidly united and move together
as one. But when the auxiliary crank arm is turned in the direction opposite
to that of the arrow shown at Figure 2, it may revolve freely on the bearing 11
independently of the main crank, owing to the fact that during this motion of the
auxiliary crank the friction of the hub on the balls or rollers is such as to drive
them in the opposite direction or towards the wider ends of their slots and against
the tension of their springs, thus preventing the said balls or rollers from bind-
ing or wedging between the hub of the auxiliary crank and the bottoms of their
notches, and thus the auxiliary crank is so connected to the main crank as that
it is capable of free backward rotation independently thereof. The form of
clutch mechanism shown is of such character that the balls or rollers are held
by their springs normally in bearing contact with the hub of the auxiliary
crank and with the bottoms of their notches and hence the auxiliary crank
becomes practically instantaneously locked to or rigidly connected with the main
crank on the application of pressure to the auxiliary crank in the direction of
the arrow at Figure 2. If the springs were not provided there might be some
lost motion in the auxiliary crank when turned in said direction until the balls

page_text: or rollers wedged between their bearing surfaces, and for the reason that such lost
motion is not desirable, I provide the said springs to keep the parts in condition.
for quick or instantaneous action and to insure that the pressure shall come on
all of the balls simultaneously. It will be understood, of course, that in lieu of
this form of clutch any other form of clutch such as a ratchet wheel and one or
more pawls may be employed without departing from the gist of my invention.
Owing to the fact that when the auxiliary crank is turned in the direction of
the arrow at Figure 2 a rigid connection is made with the clutch plate 10, I am
enabled thereby to conveniently and readily assemble the parts together. To
this end the device shown at Figure may be first inserted in the hub of the
auxiliary crank arm and then after the insertion of the balls or rollers and the
attachment of the cover plate the threaded end 9 of the device may be screwed
into the threaded hole in the main crank arm, using the auxiliary crank arm as a
lever or handle for turning the parts, as the said auxiliary crank arm, it will be
understood, cannot turn independently of the clutch plate and its integral
members when rotated in the proper direction to run in the screw 9. And it will
be seen from the foregoing that after the parts have been once thus put together
the power applied to propel the machine will always tend to maintain a tight
connection of the parts as the power is always applied in a direction to turn in
the screw.
For the purpose of detaching the device shown at Figure 4, the inner end
thereof may be provided with a short square neck or extension 21 having a central
slot or nick 22 for the application of a screw driver wherewith to turn the screw
in the reverse direction so as to enable it to be detached from the main crank
arm, after it has been started by the use of a wench applied to the squared portion
of the extension 21.
The main purpose of the auxiliary crank arm is to enable the rider while
engaged in propelling the machine to increase the total length of crank arm or to
obtain a greater leverage than that which would be possible in the use of a crank
or arm of the length represented by the main crank 2.
Referring, to the diagrammatic. view shown at Figure 6, the full lines show that
the auxiliary crank 4 has been swung up above the main crank and on the for-
ward side thereof at an angle of about thirty (30) degrees to the horizontal, and
it will be understood that when the auxiliary crank is in this position relatively
to the main crank and when the power is applied centrally of the pedal or over
the pedal axle the effective leverage of the compound crank will be proportionately
increased and will be represented by the radial dot and dash line marked a. Of
course if the auxiliary crank arm 4 were swung up farther or higher the total
crank arm would be proportionately greater and thus the increase of leverage
would continue until the arms 4 and 2 stood in the same radial line when the
total amount of leverage would be represented by the distance from the center
of the crank shaft to the center of the pedal shaft, assuming the power to be
applied at the latter point. The pedal is preferably provided with a toe clip 23
by which the auxiliary crank may be conveniently lifted or turned backwardly
by lifting the foot during the downward and forward motion of the main crank
and thus the leverage may be conveniently increased at pleasure during the pro-
pelling action of the machine.
I have shown at Figure 6 in dotted outline the foot of a rider resting upon the
pedal, and in this diagram the point of application of the power is centrally of
the pedal and around on the dash line b, the dash-and-arrow line c representing
the path of travel of the outer end of the main crank at the point of attachment
of the auxiliary crank. Whatever angle the auxiliary crank is made to assume
to the main crank just before the application of power to propel the machine
will be maintained rigidly and inflexibly during the entire time which it may
be desired to apply the power, and this rigid relationship between the two cranks
may be maintained through a half revolution of the main crank or slightly more
than the same, as indicated by the dotted positions of the cranks and pedals.

page_text: When the main crank has made a half, revolution and has come to a vertical
position below its shaft, owing to the freedom of the pedal upon its axle, carried
by the auxiliary crank, the said pedal may be turned to the dotted line position
shown, so that the foot of the rider may exert a backward push upon the cranks
as they start to travel upwardly, thus enabling the power to be applied for a
longer time than heretofore. At a point shortly beyond the lower vertical
position of the main crank the application of the power must cease and then as
the main crank moves upwardly the auxiliary crank is adapted to swing down-
wardly and inwardly by gravity and as represented by the dotted view of the
pedal and cranks shown at the third quarter of revolution of the mechanism.
During the last quarter of the revolution the auxiliary crank and pedal follow
the path represented by the arrows d and when the main crank has arrived in the
upper vertical position again as shown by the full lines, the auxiliary crank and
pedal may stand in the dotted line position of the pedal shown. At this moment,
or slightly before, the rider must swing the pedal and auxiliary crank arm
ahead of the main crank arm in the arc e, in order to bring the pedal in proper
position to enable him to apply the necessary foot power to propel the machine.
It will be understood that the extent of the upward or forward swing of the pedal
in the arc will determine the amount of leverage of the crank mechanism;
that is to say, if the pedal axle be swung out to coincide with the dash-and-arrow
circle the length of crank or lever obtained will be that indicated by the dis-
tance ca, while if it be swung out to coincide with the arc b the leverage will
be represented by the distance a a.
It will be seen that by my invention not only may the leverage be variably
increased automatically by the rider and as desired, but that the construction
is such that the power may be applied at an earlier period of time than may be
done with the ordinary crank and pedal mechanism, for it will be seen that
before the main crank 2 has arrived at its upper vertical position, or at such time,
the rider may swing the pedal ahead of the main crank and commence to apply
his power before he could possibly apply it with the ordinary crank and pedal.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a velocipede or the like, the combination of a main crank, and an
auxiliary pedal-carrying crank connected to turn rigidly with the main crank in
one direction and to turn freely independently thereof in the opposite direction.
2. In a velocipede or the like, the combination of a main crank, an auxiliary
crank pivoted thereto to turn freely independently thereof in one direction, means
for preventing it from turning in the opposite direction excepting rigidly with
the main crank, and a pedal carried by said auxiliary crank.
3. In a velocipede or the like, the combination of a main crank, an auxiliary
pedal-carrying crank, and a clutch mechanism connecting said cranks together
so as to enable them to operate in substantially the manner described.
4. In a velocipede or the like, the combination of a main crank, an auxiliary
pedal-carrying crank, means for preventing the auxiliary crank from revolving
freely on the main crank when power is applied to drive the vehicle and for
enabling the auxiliary crank to turn freely on said main crank in the opposite
direction.
5. In a velocipede or the like, the combination of a main crank, an auxiliary
pedal-carrying crank, and means provided with an automatic clutch connecting
said two cranks to cause them to form a rigid system to increase the leverage.
6. In a velocipede or the like, the combination of a main crank, an auxiliary
crank carrying a pedal and adapted to turn freely in one direction independently
of said main crank, and means for preventing the auxiliary crank from turning
in the other direction so as to effect a prolongation of the crank.
7. In a velocipede or the like, the combination of a main crank, an auxiliary

page_text: pedal-carrying crank, and a clutch adapted to allow free motion of the auxiliary
crank in one direction and to limit its motion in the other direction, whereby
the whole may form one rigid system to increase the leverage.
8. In a velocipede or the like, the combination of a main crank, an auxiliary
crank carrying a pedal, and a ball and cam clutch for connecting the auxiliary
crank to the main crank.
9. In a velocipede or the like, the combination of a main crank, an auxiliary
crank carrying a pedal, and means for automatically rigidly connecting the
auxiliary crank and main crank when forward pressure is applied to the pedal
to propel the vehicle.
10. In a velocipede or the like, the combination of a main crank, an auxiliary
crank, a pedal freely revoluble thereon, and means for automatically rigidly
connecting the auxiliary crank and the main crank when forward pressure is
applied to the pedal to propel the vehicle.
11. In a velocipede or the like, the combination of the main crank 2, the
screw 9, the bearing 11, the clutch plate 10, the balls or rollers 15, the auxiliary
crank 4 and the pedal thereon.
12. In a velocipede or the like, the combination of the main crank, the
auxiliary crank connected to turn rigidly with the main crank in one direction
and to turn freely independently thereof in the opposite direction, and a pedal
having a toe-clip and mounted to turn on said auxiliary crank.
Dated this 9th day of May 1898.
FELL & JAMES.
Agents for the Applicant.