An Improved Crank, and Method of Driving Bicycles, Tricycles, and similar Machines.
Year: 1897

page_text: Date of Application, 26th July, 1897
Complete Specification Left, 2nd May, 1898-Accepted, 9th July, 1898
PROVISIONAL SPECIFICATION.
An Improved Crank, and Method of Driving Bicycles, Tricycles,
and similar Machines.
I, LEVY JOHNSON MARKS, of 9, Queen's Terrace, Clarence Road, Longsight,
Manchester, Commercial Traveller, do hereby declare the nature of this invention
to be as follows:-
My crank instead of being fixed at one end of the same, to the axis (or axle)
upon which the driving chain wheel is placed, is put on about the centre of the
crank. The length of the crank from the centre hole to the pedal being about
half or three quarters of an inch longer, than half the diameter of the chain
wheel.
I do not pin on, or otherwise securely fix the crank on the axis, but leave it
to work loosely on the same, having a screw at the end of the axis, with a
sufficiently large head, to prevent the crank coming off.
On the opposite end of the axis to the chain wheel, I place another wheel the
same size as the chain one, without any teeth, and out side of this, I place another
crank exactly similar to the one on the chain wheel, also loosely on the axis,
with a screw on the end similar to the one on the other side.
On the inside of each crank I have two projecting short bolts, one at the pedal
end, the second at the other extremity, both bolts being so placed, that each works
on the bars of the respective wheels, close to the inner side of the rims of both.
These same bolts are firmly fixed to the cranks, and the chain and opposite wheels,
firmly fixed to the axis.
To the next bars of each wheel, behind the end of each crank (opposite to the
pedal ends) I fix an open spiral spring, in order that when back pedalling, the
strain may be taken off the wheels of the machine, and the risk of damaging them
or the machine greatly minimised.
I claim for my invention, a great increase of power, together with a corre-
sponding decrease of labour, likewise greater safety in back pedalling, consequent
upon the shortening of the cranks, from the axis to the pedals.
Another advantage I claim is my invention can be applied to any existing
machine very cheaply.
LEVY JOHNSON MARKS,
9, Queen's Terrace, Clarence Road, Longsight, Manchester.
An Improved Crank, and Method of Driving Bicycles, Tricycles,
and similar Machines.
I, LEVY JOHNSON MARKS, 9, Queen's Terrace, Clarence Road, Longsight,
Manchester, Commercial Traveller, do hereby declare the nature of this invention
037

page_text: and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
Instead of driving the cycle or other similar machines, by one end of the
cranks being pinned on to the spindle or axis carrying the chain wheel, I drive
from the circumference of the chain wheel, and in order to equalize the power
with both cranks, I place another wheel, without teeth or sprockets, upon the
opposite end of the spindle or axle, carrying the chain wheel (AA, Fig. 1)
exactly the same size as the chain wheel, but perfectly smooth on the outside
circumference.
I place my cranks across the diameter of both wheels (EE Fig. 1) fitting
loosely on the axis of each, and having holes or slots (BB Fig. 2) through which
two screw bolts pass, and which are firmly screwed to opposite bars of the two
driving wheels, close to the inner sides of the circumference. These bolts do
not bind the cranks to the wheels, but allow them to have a little play, for which
purpose, the holes nearest the pedal ends of the cranks, are slightly oval.
The heads of the screw bolts, prevent the cranks getting off the axis, and the
bolts themselves, convey the power from the cranks to the circumference of both
wheels, Fig. 2, shews the hole or slot that goes on the axis, and "D" Fig. 2,
the clamped slots, to which pedals are affixed.
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) Greater power in driving cycles, or other similar machines, and
A great saving of labour.
Dated this 2nd day of May 1898.
LEVY JOHNSON MARKS,
9, Queen's Terrace, Clarence Road, Longsight, Manchester.