Improvements in Cranks and Pedals for Velocipedes and like purposes.
Year: 1894

page_text: Date of Application, 10th May, 1894
Complete Specification Left, 22nd Dec., 1891--Accepted, 23rd Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Cranks and Pedals for Velocipedes and like
purposes.
I, CHARLES AMOS EDWARDS of 77 Palmerston Buildings, Old Broad Street,
London, Stockbroker do hereby declare the nature of this invention to be as.
follows:
-
My invention relates to the employment of means hereinafter described for
securing while the machine is in motion and at the wish of the rider an increase or
decrease in the leverage power of the crank by lengthening or shortening the
distance between the pedal and the crank axle.
One of the most important features of novelty in my invention is the extension
or reduction of the length of the crank by motion of the pedal itself while the
crank and the driving wheel are rotating.
The device or contrivance in accordance with my invention comprises the
division of the crank into two parts, the one sliding in or alongside the other part,
one of which is fixed to the axle of the driving wheel.
The sliding portion of the crank is caused to move forward or backward by
means of a screw thread conveniently located inside or alongside the said sliding
portion of the crank, and engaged at one end in a nut affixed to the non-sliding
crank at the other end of the said screw thread, and two cog wheels fixed, which
are engaged at right angles with two other cog wheels mounted on the hub of the
pedal, and which when the pedal is in motion causes the said serew thread to turn
to the right or to the left, and to carry with it either forward or backward the
sliding portion of the crank to which the said pedal hub is affixed.
The movement forward or backward of the sliding crank as before mentioned
is caused by locking either one or the other of the cog wheels placed on the pedal
hub, which locking is effected by means of levers conveniently placed on the pedal
and worked by the foot. For the purpose of locking either wheel the axle of
each is carried through the whole distance of the pedal hub and fitted with
separate handles protruding outside the said pedal hub.
The two parts forming the crank, viz. the sliding part and the stationary
part are of different length, so that when the crank is reduced to its minimum
length a portion of the sliding part will protrude beyond the axle of the driving
wheel to which the crank is fixed while ou the other hand when the crank is fully
extended both pieces are only engaged in one another over such distance as may
be found necessary to secure strength and efficiency.
If more convenient the ecrank may be made of one piece instead of two, in
which case an opening or slide will be reserved in such portion of its length as is
required, and the screw thread will be placed inside the said slide or opening.
The cog wheels at the end of the screw thread as before mentioned will then be
fixed to a tube having a similar thread inside, so that it may move alongside the
said screw thread when the cog wheels are rotating in a manner similar to the one
above mentioned, and the hub of the pedal will be made to slide in the said
opening or slide, together with the said tube.
It will be obvious that the above mechanism can be made in any suitable
material. and I do not confine myself to any particular method of fixing the

page_text: various pieces above mentioned together, so long as the working of them shall
effect the purposes above mentioned in the manner above described or similar
thereto.
Dated thin 10th dent M1004
S. S. BROMHEAD,
97, Newgate Street, E.C., Agent for Applicant.
Improvements in Cranks and Pedals for Velocipedes and like
purposes.
"I, CHARLES AMOS EDWARDS of 77 Palmerston Buildings, Old Broad Street,
London, Stockbroker, 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 the employment of means hereinafter described for
securing while the machine is in motion and at the wish of the rider an increase
or decrease in the leverage power of the crank by lengthening or shortening the
distance between the pedal and the crank axle.
One of the most important features of novelty in my invention is the extension
or reduction of the length of the crank, by motion of the pedal itself while the
crank and the driving wheel are rotating. The device or contrivance in
accordance with my invention comprises the division of the crank which for
distinction I call the geared crank into two parts, the one sliding in or alongside
the other part, one of which is fixed to the axle of the driving wheel.
The sliding portion of the crank is caused to move forward or backward by
means of a screw thread conveniently located inside or alongside the said sliding
portion of the crank, and engaged at one end in a nut fixed to the non-sliding
part of the crank and at the other end of the said screw thread, attached to a
mitred cog wheel which is engaged at right angles with two other mitred wheels
mounted on the hub of the pedal, and which when the pedal is in motion cause
the said screw thread to turn to the right or to the left, and to carry with it
either forward or backward the sliding portion of the crank to which the said
pedal hub is affixed. Such ordinary or special contrivance as I may find suitable
may be affixed to either end of the said screw thread or on either side of the said,
nut for the purpose of checking or stopping the rotation of the said screw thread'
when the shorter or greater length of the crank is reached.
The movement forward or backward of the sliding crank as before mentioned
is caused by locking either one or the other of the mitred wheels placed on the
pedal hub, which locking is effected by means of levers conveniently placed on
the pedal and worked by the foot.
For the purpose of locking either wheel the axle of each is carried through the
whole distance of the pedal hub and fitted with separate handles protruding
outside the said pedal hub.
The two portions forming the crank, namely the sliding part and the
stationary part are of different length, so that when the crank is reduced to its
minimum length a portion of the sliding part will protrude beyond the axle of the
driving wheel to which the crank is fixed, while on the other hand when the
crank is fully extended both pieces are only engaged in one another over such
distance as may be found necessary to secure strength and efficiency.
If more convenient the crank may be made of one piece instead of two, in which
case an opening or slide will be reserved in such portion of its length as is required,
and the screw thread will be placed inside the said slide or opening.

page_text: The mitred wheels at the end of the screw thread as before mentioned, will
then be fixed to a tube having a similar thread inside, so that it may move along-
side the said screw thread when the cog wheels are rotating, in a manner similar
to the one above mentioned, and the hub of the pedal will be made to slide in the
said opening, or slide together with the said tube.
I will now describe the invention with reference to the accompanying drawings
in which;
'
Fig. 1 shows a plan of my improved bicycle pedal and a side elevation of the
extensible crank nearly extended to its full length.
Fig. 2 shows an end view of the crank arm, shortened as compared with
Fig. 1.
Fig. 3 shows a sectional elevation of my improved pedal and crank, with the
internal working parts exposed to view.
Fig. 4 shows an end view of the pedal with the cap d removed.
Fig. 5 shows a side elevation of Fig. 4.
Fig. 6 shows a plan view of the inside of the cap d, with spring d', in position.
Fig. 7 shows a cross section of the pedal on the line 1-2 of Fig. 1.
q, is the crank with sliding arm a', and sleeve a².
,, are discs of brass or other metal inserted in the sliding arm a¹, to indicate
to the rider how far the pedal is extended.
C
is the pedal on the outer end of which is secured a cap or small cover d, fitted
with spring d', which cap encloses the pawl and step mechanism for connecting
the treadle levers, with the winding up action for lengthening or shortening
the crank arm a¹. The spring & embraces the two short levers g, which work in
unison and returns them to their normal position after being operated by the
spindles e, e.
e, e, are spindles on to each end of which is secured one of the curved levers ƒ, ƒ",
operated by the foot of the rider.
ff, are two curved levers placed on the outer end of the pedal, and which when
operated by the foot of the rider have the effect of shortening the crank as
hereafter explained.
,, are two other semi-circular cranked levers placed on the near end of the
pedal, which have the office to lengthen the crank.
All these levers are fitted with roughened treads f* to engage the foot of tlie
rider.
Referring to Fig. 4, 9 g are short levers working in unison fixed on the end of
the spindles e, e, connected at their ends to each other by links h, h.
i, i, are pawls firmly attached to links h, h, which pawls engage with the two
ratchet teeth j, in the disk k.
g', y are pawls connected to the levers g, g, engaging simultaneously with the
ratchet teeth, (shewn in dotted lines) in the under disc l. m, is the solid central
spindle of the pedal which is connected to the upper disc k.
The disc, is connected to a hollow spindle ', outside m, as shewn in Figs. 3
and 7.
Referring to Fig. 3, n is a toothed mitred wheel mounted on the hollow
spindle m, and gearing with a similar wheel o, mounted on a screwed shaft p.
, is another toothed mitred wheel mounted on the inner spindle m, and gearing
with mitred wheel'o, for reverse motion.
7, is a fixed tube which has a collar, at its upper end which is tapped to
receive the screwed spindle p. This tube q, is fixed to the sliding arm a¹. When
therefore the spindle p, is rotated by the mitre wheel o, the sliding arm a', is
drawn upwards or downwards according to the direction of the motion thereby
lengthening or shortening the crank.
The action of the mechanism of the crank and pedal is as follows:-
-
To shorten the crank, one of the curved levers, is pressed down by the foot of
the rider, thereby causing the pawls i, i, to engage with the teeth j,j, of the upper
disk k, and preventing the spindle m, from rotating. The lower disc 1, being free

page_text: the hollow spindle m², and mitre wheel a, rotate which causes the screwed spindle,
to screw up and thus shorten the crank.
To lengthen the crank the alternate curved levers, must be pressed by the
rider's foot when the reverse action takes place, and the screwed spindle p,
unscrews and lengthens the crank.
It will be obvious that the above mechanism can be made in any suitable
material, and I do not confine myself to any particular method of fixing the
various pieces above mentioned together, so long as the working of them shall
effect the purposes above mentioned in the manner above described or similar
thereto.
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 1
claim is :-
1. In a pedal and crank for bicycles and like purposes, the method of effecting
the extension or contraction of the crank-bar by motion communicated by means
of enclosed mechanism from the pedal itself, during the revolution of the crank as
herein described and set forth.
2. In a pedal crank for bicycles and like purposes the hollow telescopic tube a,
with its sliding end a', fixed nut r, and rotating screw p, and with or without the
sleeve a, and indicating discs 61, 62, as herein described and set forth.
3. In a pedal or treadle for bicycles and like purposes, the cap d, hollow treadle
bar m, with the internal spindles m¹, m, curved levers f, f, and mitred
wheels n, n', o, engaging and disengaging arrangement of spindles e, e, ratchet
wheels k, and I, cross levers g, links h, pawls i, and y', as herein described and set
forth.
Dated this 22nd day of December 1894.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.