An Improvement in the Cranks of Bicycles and other Cycles.
Year: 1897

page_text: Date of Application, 27th Oct., 1897
Complete Specification Left 22nd Dec. 1897-Accented 5th Mar.
1898
PROVISIONAL SPECIFICATION.
An Improvement in the Cranks of Bicycles and other Cycles.
I, HENRY CHOLMONDELEY PENNELL, of Palace Mansions, Addison, Bridge,
Kensington, W., in the County of London, Gentleman, do hereby declare the
nature of this invention to be as follows:--
a
"
An invention to increase the diameter (and therefore the power) of the stroke of
the crank of a bicycle or other cycles without increasing the actual total circum-
ference of the stroke, so far as the rider is concerned. This is effected by means of
compound crank," the long, or main, arm of the crank having a shorter or
supplemental arm disc or revolving plates attached to its extremity (by means
of a spindle and appliances or other rotating mechanism permitting of a free revolu-
tion) and to the end or rim of which supplemental arm or disc the pedal is
attached by any of the ordinary methods permitting it to revolve freely on its axis.
The main crank will thus for practical purposes be lengthened by the length of the
supplemental arm or dise which is "extended" during the forward and downward
movement whilst during the revolving and at the highest point of the "stroke"
the pedal will be proportionately lowered or depressed.
Dated this 27th day of October 1897.
"
H. CHOLMONDELEY PENNELL.
COMPLETE SPECIFICATION.
An Improvement in the Cranks of Bicycles and other Cycles.
I, HENRY CHOLMONDELEY PENNELL, of Palace Mansions, Addison, Bridge,
Kensington, W., in the County of London, 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 an improvement in the cranks of bicycles and other
cycles.
The invention consists of an apparatus to increase the leverage (and therefore
the power) of the stroke of the crank of a bicycle or other cycles without increasing
in the same proportion the actual circumference of the stroke, so far as the rider is
concerned. This is effected by means of a compound crank, the long, or main, arm
of the crank having a shorter or supplemental arm, disc, or revolving plate (or
plates) attached to its extremity (by means of a spindle and appliances or other
rotating mechanism permitting of a free revolution) and to the end, or rim, of
which supplemental arm dise or revolving plate (or plates) the pedal is attached by
any of the ordinary methods permitting it to revolve freely on its axis. The main
Price R71

page_text: crank will thus for practical purposes be lengthened by the length of the supple-
mental arm, disc, or revolving plate (or plates) which in action is extended at the
points where the propelling force is applied (that is, during the forward and down-
ward movement, and contracted at the other points where, no propulsive force is
exerted (that is, during the "recovery," or upward movement,) and until the pedal
has overpassed the highest point of its orbit instead.
The increase of leverage will be in proportion to the length between the centre
of the axis of the supplementary arm, disc, or revolving plate (or plates) and the
centre of the pedal spindle.
The supplemental arm may be of any length, and the disc, or revolving plate
(or plates) of any diameter required, subjecting to the limitation imposed by the
space necessary between the pedal and the ground; and in this connection an
important advantage is incidentally gained by the invention above described in that
by its action the riders seat is naturally lowered in proportion as the length (or
diameter) of the supplemental arm, disc, or revolving plate (or plates) exceeds
when extended, the length of the main crank.
And in order that my invention may be thoroughly understood, I now proceed to
describe the accompanying drawing thereof, reference being had to letters and
figures marked thereon.
Fig. 1, is a side elevation with the revolving disc and other parts in section.
Fig. 2, is a front elevation of the disc pedal and crank.
Fig. 3, is a back elevation of Fig. 2.
In carrying my invention into practice I provide an ordinary bicycle crank
(which may, if requisite, be supplemented at the extremity by two or more lateral
or other projections or extensions forming extra supports for the back disc). A
countersunk screw hole is drilled below the swell c in order to fix one half of the
disc f to the crank a by a countersunk screw g. Inside the discs f and f¹ I form
grooves (or a groove) to receive a number of balls forming ball bearings and
through the discs I insert a screw g with ball bearings under the head h.
The outside half of the disc f¹ revolves on the ball bearings j and į and around
the screw on the disc's axis. The apparatus is operated by means of the pedal b
attached to the outer disc f', and as the said pedal, disc and crank revolve on the
axle the leverage of the stroke of the crank is increased, without increasing for
practical purposes, so far as the rider of the cycle is concerned, the actual circum-
ference of the stroke. The disc f¹ freely revolves on its axis as the pedal is 3
worked by the foot of a rider, and the crank is lengthened by the disc (from its
centre to centre of pedal spindle) which is extended during the forward and down-
ward movement whilst during the "recovery," or upward movement, of the crank
until it has overpassed the highest point of its orbit the pedal will be proportion-
ately lowered or depressed.
די
.
If preferable the disc mechanism may be fitted to the end of any ordinary crank
by drilling and tapping the necessary holes in the said crank to receive the screws
for fixing the apparatus.
The pedal may be of the ordinary
66
"
screw-in pattern, screwing into the
supplementary crank, arm, disc or revoling plate or plates instead of as usual, 4
into the main crank itself.
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 is:-
1. In an apparatus for cranks of bicycles and other cycles, the combination of
the various parts of mechanism fully described in the above specification and
illustrated in the accompanying drawings for the purpose specified.
2. In an apparatus for cranks of bicycles and other cycles, the combination of
the various parts of mechanism or their equivalent as fully described in the above
specification for increasing the leverage, without practically increasing the cir-
cumference of the stroke of the crank.

page_text: 3. In an apparatus for cranks of bicycles and other cycles, the combination of
the pedal b disc f revolving disc fi screws and g ball bearings j and i and
spindle & fitted and fixed to the end of cranks, substantially as herein described and
according to the accompanying drawings.
4. In an apparatus for cranks of bicycles and other cycles, the combination of
the fixed disc f revolving disc fl screw g and pedal fitted at the end of cranks
for increasing the leverage of the stroke, without practically increasing the cir-
cumference, substantially as above described.
Dated this 22nd day of December 1897.
J. P. BAYLY,
18, Fulham Place, London, W., Agent for the Applicant.