An Improved Construction of Crank for Bicycles and the like.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improved Construction of Crank for Bicycles and the like.
We, REES RODERICK, of Pandy Cottages, Hirwain, in the County of Glamorgan,
Engineer, and WILLIAM ALBERT WATKIN GEORGE, of 78, High Street, Hirwain,
in the County of Glamorgan, Chemist, do hereby declare the nature of this inven-
tion to be as follows:-
This invention relates principally to a novel form of crank, that enables the
rider to utilize the downward pressure of the foot, in a better way, than has hitherto
been employed, and thus he is capable of using a very much higher gear than
is at present customary.
The pedal upon which the pressure of the foot is applied, has its central pin
traversing radially within a slot formed in the crank, or the crank can be a square
bar, with a square opening; formed in the crank pin, which may slide upon the
square or flat shaped stem, of the crank; the part upon which the pedal works,
being rounded in the usual way.
To the inner end of the crank pin, we attach one end of a coiled spring, of a
volute shape, the other end being secured to the root of the crank, or spindle.
The tension of the spring is so arranged, that the pedal is normally pulled
inwards towards the centre of the crank spindle, and when the rider presses the pedal
downwards, and away from the centre of the crank spindle, the spring is expanded
to an extent dependent upon the amount of downward pressure applied, thus in-
creasing the effective length of the crank during that portion of its stroke, wherein
the rider can exert his power most effectively.
The natural energy of the spring drives the crank pin inwards towards the centre
during the remainder and up portion of the stroke.
We also, in an alternative method of working, place a spiral or helical spring,
within a hollow formed in the crank, which has the effect of pulling the crank
pin, inwards as before described; the pressure of the rider's foot upon the pedal,
forcing the pedal outwards and away from the centre of the spindle.
In applying this invention to a bicycle we prefer to employ a larger rear or .
driving wheel; than bicycles generally at present have, and the front wheel we
prefer to make somewhat smaller than is usual.
The top bar of the cycle would be dispensed with if found in the way.
Dated this 25th day of May 1807
PHILLIPS & LEIGH,
Agents for the Applicants.

page_text: An Improved Construction of Crank for Bicycles and the like.
We, REES RODERICK, of Pandy Cottages, Hirwain, in the County of Glamorgan,
Engineer, and WILLIAM ALBERT WATKIN GEORGE, of 78, High Street, Hirwain,
in the County of Glamorgan, Chemist, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
1
This invention relates to an improved construction of crank for cycles, and its
object is to enable the rider to utilise the downward pressure of the foot to a
greater advantage than is possible with the ordinary crank hitherto employed,
and to also enable a much higher gear than usual to be employed.
The pedal upon which the pressure of the foot is applied has its central pin
traversing radially by means of an arrangement formed in the crank.
The crank itself is secured to the driving spindle in the usual way and has formed
upon its stem lugs within which slide that portion of the crank which carries the
pedal pin and upon which the pedal works.
This portion of the crank is capable of extension and slides upon the fixed crank
stem.
A spiral spring is attached to the sliding portion of the crank and is passed down
through a hole drilled almost the entire length of the crank stem, the other end
of the spiral spring being attached to a pin or other arrangement at the bottom
of the hole in the fixed part of the crank.
The part of the crank to which the pedal pin is attached is therefore capable of
considerable extension, so that when the rider's foot is pressed downwards, the
crank automatically increases in length, stops being provided to limit the extent.
Upon the rider releasing his downward pressure upon the pedals the spiral
spring pulls the sliding part of the crank home to its normal position.
Instead of a spiral spring acting in tension as before described, the same
principle of crank may be employed whereby the sliding part of the crank may be
brought back by a spring placed so that its power may be exerted by compression,
the principle of the sliding crank being the same in either case.
According to our invention, which we will now proceed to describe in detail with
reference to the accompanying sheet of drawings forming part of the said descrip-
tion, and in which:-
Figure 1 is an elevation of a crank made according to the invention.
C is the driving spindle upon which both the crank and chain wheels are placed.
D is the boss of the crank secured to the spindle in the usual way.
E is the stem of the crank upon which lugs F, F, are formed. These lugs are
bored out so that the sliding stems G, G, slide within them.
His a cross-head to which the sliding stems G are attached.
I is the pedal pin of usual construction and upon which the pedal is placed.
J is a spiral spring passing down the centre of the crank stem and secured thereto
by a pin at K, and to the cross-head by a pin at L.
The dotted lines show the sliding part of the crank drawn out to its fullest
extent.
Figure 2 is a side view of the crank shewing the driving spindle C and pedal
pin I broken off for convenience of illustration.
M, M, are screwed stops attached to the end of the sliding stems G.
Figure 3 is a section through the crank at A, B.
G, G, are the sliding stems, and F, F, the lugs through which they pass.

page_text: E, is the stem of the crank, and N is the hole bored into its stem within which
the spiral spring works.
Figure 4 shows an arrangement of crank whereby the working parts are pro-
tected from dirt.
D is the boss of the crank.
C is the driving spindle, and E the stem of the crank.
H the crosshead with the sliding stems G.
I is the pedal pin, and
J the spiral spring.
O is a part recessed out of the face of the crank stem and within which works the
sliding stems G and spiral spring J.
The lugs F being formed solid within the stem.
P, P are screw holes for attaching the cover plate to the face of the crank to
prevent access of dirt to the working parts inside.
R, R, are stops to prevent the entire withdrawal of the sliding stems G.
Figure 5 is a section through Figure 4 at S, T.
E is the stem of the crank.
G, G, the sliding stems of the crosshead H.
J the spiral spring, and
U the cover plate.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
wo claim is: -
1. A sliding crank extended by means of the rider's foot in pressing downwards,
and a spiral or coiled spring either in tension or compression for the purpose of
drawing it back again into its normal position, as described.
2. A sliding crank composed of the parts H-G and D-F slidably working one
within the other and the spring J connecting the said parts as described and
shewn in Figures 1 and 2 of the accompanying drawings.
3. A recessed crank stem within which a spiral spring is placed of sufficient
length as to be capable of the extension necessary, as described and for the purposes
set forth.
4. A crank stem recessed out so as to contain a coiled spring and the stem of
a sliding pedal covered in by a plate to protect the working parts from dirt, as
described and shewn in Figures 4 and 5 of the accompanying drawings.
Talad hi 1141 dave of Waluminur 1000
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.