Improvements in Pedals for Crank Powers.
Year: 1894

page_text: Date of Application, 24th Apr., 1894-Accepted, 9th June, 1894
COMPLETE SPECIFICATION.
Improvements in Pedals for Crank Powers.
I, ANDREW JACKSON HOYT, of 258 South 10th Street, in the City of
Philadelphia, State of Pennsylvania, U.S.A., Artist, 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 certain improvements in that class of pedals for bicycles
or other machines moved by the foot in which the pedal is prevented by locking
devices from turning forward on the pedal pin when pressure is applied to the
outer foot rest during the descending movement of the crank, and thus as the
pedal cannot turn on the pin, the effective length of the crank is virtually
increased by the extent to which the pedal extends forward beyond the pedal pin.
The object of my invention is to provide for locking the pedal in position for a
somewhat longer time than heretofore for which purpose I make the pedal with a
rear foot rest, which yields so as to be lower and higher than the front foot rest
at different parts of the revolution of the crank.
Fig. 1 of the accompanying drawings is a perspective view of one form of pedal
according to my invention.
Figs. 2, 3 and 4, are diagrams illustrating three different positions of a pedal
of modified form.
Fig. 5 is a plan of the pedal, partly in section.
Fig. 6 is a side view partly in section.
Fig. 7 is a detached view of the foot rest.
Fig. 8 is a longitudinal section of a modified form of pedal with a special
construction of the rear foot rest.
Fig. 9 is a plan of part of the same.
Figs. 10 and 11 are longitudinal sections of another modification of pedal.
Fig. 12 shews a cam substituted for the spring.
Fig. 13 shows the pawl provided with a cushion to absorb shocks.
The pedal illustrated in Fig. 1 is the form preferred but the other figures
illustrate modifications within my invention. The action of the pedal may be best
understood on reference to Figs. 2, 3 and 4, the pedal in these diagrams being
similar to that shown in the detail views, Figs. 5 and 6.
As shown in Fig. 1 the crank arm A' may be bent so as to bring the pedal
nearer to the frame of the machine.
Side arms B mounted on the pedal pin A carry at their outer ends the cross
bolt C on which the foot plate D is carried by a coiled spring C, tending to
keep the rear end of the foot plate raised. The foot of the rider is steadied on
the plate by side clips d d and a toe clip. As the pedal revolves the spring
yields so that the foot is always kept in the proper position relatively to the
pedal.
In the pedal shown in Figs. 2 to 7, A is the pedal pin which is rigidly connected
to the crank arm and has fixed on it a toothed catch a, with which are adapted to
engage a pair of spring pawls & carried by one of the side hars B which turn on
ball bearings on the pedal pin, being free to turn backwards during the greater
part of the downward stroke of the crank and being resisted by engagement of
the pawls and toothed catch so that during the downward stroke the pressure upon
the outer foot rest D serves to lock the latter to the pedal pin and thus increases the
effective length of the crank to the extent of the distance between the pedal pin
and outer foot rest D.
The pedal should be tilted upward in front at the beginning of the downward

page_text: thrust when the pedal is first locked to the crank, for the more the front of the
pedal is then tilted up the longer does the pedal remain locked to the crank, and
thus the longer is the stroke before the foot touches the rear foot rest and throws
the pedal backward. I therefore provide a rear foot rest D' which projects some
distance above the level of the front rest D this rest D₁ being elastic, so that it
serves as a support for the foot when subject to light pressure, but yields to heavy
pressure.
When the crank is in the position shown in Fig. 2 therefore, the rear foot
rest D¹ serves as a means of depressing the rear of the pedal to the desired extent
without excessive inclination of the foot, the light pressure at this time exerted
upon the pedal not being sufficient to compress the rear rest.
When the pedal reaches the position Fig. 3, the pressure of the foot is
sufficient to compress the rest D¹ without depressing the rear end of the pedal
because the pressure upon the front foot rest is still heavier than that required to
compress the spring of the rear rest. D', thus the pedal remains locked to the crank
during that portion of the stroke in which the power can be most effectively
applied. When the crank is rising, the pressure upon the rest D' serves to shift
the position of the pedal, as shown in Fig. 4, and gradually lift its front end until
it again assumes the position shown in Fig. 2.
The elasticity of the rear rest D' may be obtained in various ways, as shown in
Fig. 7 the wire forming the rest is bent in a series of loops. Ŏr as shewn in
Figs. 8 and 9 the rest may be made in the form of a coil suspended by bent
arms projecting from coils g secured to the opposite side bars B.
In Figs. 10 and 11 are shown pivotted foot rests the front and rear rests con-
nected by a rod i so that when the front rest is elevated, the rear rest is depressed,
and vice versu.
The rear rest may be acted upon by a suitable spring, m, this spring tending to
maintain the rests in the position shown in Fig. 10, until the pressure of the foot
depresses the rear rest and raises the front rest, this operation taking place after
the pedal passes the position shown in Fig. 2, and before it reaches the position
shown in Fig. 3.
The pedals shown in Figs. 2 to 7 and in Figs. 10 and 11 are reversible pedals,
that is to say, they are centrally pivotted and are equally operative either side up,
but it is preferable in some cases to pivot the pedal closer to the rear foot rest
than to the front rest, as shown in Fig. 8, in order to provide for an increased
amount of leverage when the pedal is locked to the crank.
In Fig. 12 is shown a cam D³ as a substitute for the springs, the cam acting
upon the rear of the foot plate D' to raise it during a certain portion of the stroke
and to release it during another portion.
The pawls may have a cushion of rubber or other elastic material as shown
in Fig. 13 to prevent shock when the pawl engages the ratchet.
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 in respect of crank pedals, is :-
1. The construction of pedal with a yielding rear foot rest, and ratchet and
pawl for preventing the forward rotation of the pedal on the pedal pin, substantially
as described.
2. The construction of pedal with a foot plate carried by a coiled spring on a
cross bolt tending to raise the rear of the foot plate, with steadying clips for the
foot and with ratchet and pawl to prevent forward rotation of the pedal arms on
the pedal pin, substantially as described.
1 ..
سم
ABEL & IMRAY,
Agents for the Applicant.