Improvements in Cranks for Driving Cycles, Engines, and other Machinës.
Year: 1894

page_text: Date of Application, 7th Nov., 1894.
Complete Specification Left. 6th Aug., 1895 Accepted, 7th Sept., 1895
PROVISIONAL SPECIFICATION.
Improvements in Cranks for Driving Cycles, Engines, and other
Machinës.
We, HARRY DEWEY, of Lodge Road, Redditch, Fitter, 'and CHARLES ERNEST
LADBURY, of St. George's Road, Redditch, Engineer, both 'in the County' of
Worcester, do hereby declare the 'nature of our said invention to be as follows:-
Our invention has for its object improvements in cranks for driving cycles,
engines, and other machines and is for the purpose of giving maximum power with
a minimum amount of labor and also for the economy of room in such mechanism
and so that the crank will accomplish the greatest amount of work with a minimum
amount of travel.
Our invention is as follows:
Instead of keying or otherwise fastening the crank to the driving, shaft of
cycles or other machines we mount the crank in a bearing which is fast to and.
revolves with the driving shaft. The crank is therefore capable of a sliding action
which brings the crank pin either further from, or nearer to the crank shaft. The
ends of the crank revolve inside a strap which is made to a curve; parabolic or
otherwise eccentric to the centre of the crank shaft so that as the crank with its
pin moves round the axis of the shaft the crank pin is brought nearer to or carried
further from the centre. By this means the pin is kept at the most advantageous
point when the heaviest work is being performed and travels the shortest possible
distance when no work or the least work is being performed. Thus both
economy; of labor and time is obtained as well as maximum results from the power
applied.
Dated this 6th day of November 1891.
•
GEORGE BARKER,
77 Colmore Row, Birmingham, Agent for Applicants.
Improvements in Cranks for Driving Cycles, Engines, and other
Machines..
We, HARRY DEWEY, of Lodge Road, Redditch, Fitter, and CHARLES ERNEST
LADBURY of St. Georges Road, Redditch, Engineer, both in the County of
Worcester, do hereby declare the nature of our said invention and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement :-
Our invention has for its object improvements in cranks for driving cycles,
engines and other machines and is for the purpose of giving maximum power
with a minimum amount of labor and also for the economy of room in such
mechanism and so that the crank will accomplish the greatest amount of work
with the smallest travel.
In order that our invention may be clearly understood and more easily carried
into practise we have appended hereunto a sheet of drawings upon which we

page_text: have given an example of our invention as applied to the driving or pedal shaft
of a bicycle.
Figure 1., is a side elevation of the driving or crank shaft of a bicycle with our
invention applied thereto.
Figure 2., is a plan of the same.
The frame A is broken off in both views as it is quite unnecessary to show more
of the machine than the driving portion.
The bearing box B is fast to the pedal spindle which passes through the junction
of the frame A in the usual manner and is composed in the example shown of a
front plate and back plate 62. On the other side, that is on the chain driving
wheel side, the bearing box B is attached to the arms of the chain driving wheel
which is the same thing as both the bearing boxes B and the wheel F move
together. Now each of the cranks E carry a pin el which works in a suitable hole
or bearing in the loose straps K, K, which surround the eccentric blocks k¹, k¹, and
these blocks are fast by any suitable means such as the bolts shown, to lugs a', a¹,
⚫ which are fast to the frame itself. Now the cranks E are mounted loosely in the
bearing boxes B between suitable friction rollers 3, so that they are enabled to
slide backwards and forwards as the eccentric straps K K revolve upon the
eccentric blocks h, k, and thus the pedals P, P, are carried further away from
the driving spindle at the X side of driving spindle and nearer to the driving
spindle on Y side of the driving spindle. For going forward the driving wheel
turns as per the arrow S the leading wheel being at the X end and the driving
wheel at the Y end. It will thus be seen that as the foot comes down with each
pedal at X or the front side of the spindle the leverage of the crank is increased
and as the foot rises at the Y side of the spindle the leverage is proportionately
less. We therefore obtain the large leverage just where it is required and thus
utilize the power at the right position and have the small travel where no
driving work can be performed. It will be evident that the round eccentric straps
and blocks may be exchanged for blocks of other shapes such for instance as two
eliptical straps with the pin e¹ working between the two straps or in a groove.
We do not confine ourselves to the shape of the crank or box or to the exact
positions in which they are shown as they may be varied to suit circumstances.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The improved driving mechanism for cycles and other machines consisting of
the sliding cranks mounted in the boxes B and connected to the straps K and
operated by the eccentric or similar blocks substantially as and for the purpose
herein set forth and as shown upon the drawings.
Deted this 2nd do of
GEORGE BARKER,
77 Colmore Row, Birmingham, Agent for Applicants.
GEORGE BARKER,
77 Colmore Row, Birmingham, Agent for Applicants.