Improvements in Driving Gear for Cycles.
Year: 1898

page_text: Improvements in Driving Gear for Cycles.
I, JOHN WALKER FERRIER ROSE, of 13, Jasper Road, Upper Norwood, in the
County of Surrey, Insurance Broker, do hereby declare the nature of this inven-
tion, to be as follows:-
This invention is designed to provide a driving gear for cycles which will enable
the rider to develop greater power than heretofore, and in which two pairs of
cranks are employed and are caused to act in the manner of variable throw cranks.
In carrying out my invention, and assuming the same to be applied to a bicycle,
I provide a pair of crank axles and mount them parallel, one in advance of the
other, in the frame of the cycle which, for this purpose, is suitably constructed
and to the outer extremities of such axles I fit cranks of any convenient form.
The cranks at each side of the frame of the machine are connected together by
pedals or foot plates which are mounted on pedal pins so that they work in unison.
These foot plates project beyond the forward cranks, and by applying the foot
pressure to them on such projecting part an effect similar to an extension of the
effective length of the cranks is secured. Thus, by varying the position of the
foot on the foot plates an action similar to that of variable throw cranks is
obtained.
I may further ensure the cranks working in perfect unison, by placing eccen-
trics on the inner side of the cranks and connecting their straps together by a
rod or bar, and said straps, or eccentrics, may be arranged to run in ball bearings.
Or instead of the eccentrics and their straps, I may use any other mechanism
suitable for the purpose, provided the arrangement be such as to cause the pedals
or footplates to preserve their horizontality during the movement of the cranks.
The pedals or footplates are attached to the two cranks at each side of the
machine, and are of such a length as may be found most convenient for the foot
of the rider; they are placed forward of the axle of the front crank so that the
heel shall occupy a position approximately equidistant between the two pedal
pins, thereby providing for an increased leverage or throw on the outward stroke
of the cranks.
The driving chain and its sprocket wheel (which latter might be mounted on
either of the axles) remain the same as in ordinary gear.
Dated thin 27th day of May 1898

page_text: tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had to the
accompanying drawings and to the letters and figures marked thereon, that is
to say:-
This invention is designed to provide a driving gear for cycles which will enable
the rider to develop greater power than heretofore, and to apply the power in a
more natural and less fatiguing manner than is possible with ordinary driving
gear.
In carrying out my invention, I employ two pairs of cranks, which are caused
to act in the manner of variable throw cranks. To this end, I provide a pair of
crank axles mounted parallel one in advance of the other, in the frame of the
cycle which, for this purpose, is suitably constructed, and to the outer extremities
of such axles I fit the cranks which may be of any convenient form.
The cranks at each side are connected together by pedals or foot plates which
are mounted on pedal pins so that they work in unison.
The pedals or foot plates project beyond the forward cranks and by applying the
foot pressure to them, a result similar to an increase of the effective length
of the cranks is obtained, and the pressure of both the heel and the toe can be
applied effectively for the purposes of propulsion, thus causing the pedalling action
to assimilate very closely to that of walking, and avoiding the strain being thrown
entirely on one particular set of muscles.
Reference being had to the drawings;
Figure 1 is a side view of one form of my improved driving gear, with the cranks
on one side commencing their down stroke.
Figure 2 is a detached view of the cranks on the opposite side of the machine,
shewing the means for ensuring their working in unison.
Figure 3 is a plan of the said gear, the cranks having reached the middle of
their down stroke, and alternative means being used for ensuring the cranks
working together.
Figure 4 is a detail view of the said alternative means.
Figures 5, 6, and 7 correspond to Figures 1, 2 and 3 but shew a slightly
modified form of driving gear.
a are the cranks which are of any convenient type, bare the crank axles, and
is the frame of the machine. These parts are all substantially of the ordinary
kind, bui owing to the fact of two cranks. being employed, the crank bracket cl
is extended as, shewn in Figure 1, and in Figure 5, to enable it to accommodate
the crank bearings.
d are the extended pedals or foot plates, which are of such a length as may be
suitable for the foot, and which are so arranged that. the heel occupies a position
between the cranks, whilst the toe projects considerably in advance of the end of
the front crank, the pedal preserving its horizontality all the time. As shewn in
the drawings, the pedals may have rubber treads (Figure 5), or be provided with
rat-trap teeth (Figure 1). The inner side bar d' of each pedal frame extends as
far as the end of the rear crank, and is connected thereto by means of a ball
bearing so that the depression of the pedal operates both cranks and causes them
to work in unison. To the said bar is also connected a guard plate d² to
prevent any possibility of the foot coming in the way of the cranks, and a toe
clip d³, of any ordinary kind, is carried by each pedal.
In order to further ensure the cranks working in unison, I may provide suit-
able mechanism which will serve to gear the crank axles together, and will allow
the pedals or footplates to preserve their horizontality.
For this purpose, I may provide eccentrics. e (Figure 2) on the crank axles b,
the straps el of these eccentrics being connected by a rod or rods e³, and having
antifriction balls interposed between them and the eccentrics.
Or, instead, I may employ two chain pinions f (Figure 4) mounted one on each
axle b, and connected to a chain f.

page_text: The arrangements for transmitting the rotation of the cranks to the driving
wheel, may be substantially similar to those of an ordinary cycle.
For instance, in Figure 1, the driving sprocket wheel g is mounted on the axle
of the front crank, and the chain g engages a pinion on the hub of the rear
wheel in the ordinary manner.
In Figure 5, however, I employ two driving sprockets g, one on each axle, the
chain passing over both of them and thus keeping them in perfect unison, and
effectually controlling the simultaneous rotation of the cranks without the use of
any other mechanism.
In the case of a tricycle, the chain drives a pinion on the rear axle in the
ordinary way, such pinion being enclosed in a box or casing g³ containing the
usual differential or balance gear for enabling the wheels to turn at different
speeds, as in going round curves. With this arrangement however, it is neces-
sary to provide means for tightening up the chain between the two sprockets g,
and this may conveniently be done by mounting the axle of the front one in
eccentric adjusting discs of the well known kind, so that by turning the latter the
distance between the sprockets can be varied slightly.
Referring now to the action of the improved driving gear, which is applicable
to all kinds of cycles, it will be readily understood that when the toe and heel
are pressed upon the pedal, the former exercises a preponderating purchase om
the front crank, due to the overlapping of the pedal, and the heel acts similarly
with regard to the rear crank, owing to the distance it is in advance of the same,
these actions being at a maximum when the cranks are in a horizontal position in
the middle of their down stroke, as in Figure 3.
Furthermore, as the whole foot is applied to the pedals, the powerful muscles
which act when giving a downward thrust with the heel, are brought fully into
play, and a much greater force can be exerted with less fatigue and strain than
can possibly be done with an ordinary driving gear wherein all the force has to
be applied through the front portion of the foot. Consequently, the action of
propelling a cycle provided with my improved gear is much superior as an exercise
to ordinary cycling.
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. A driving gear for cycles comprising two pairs of cranks turning in unison
and carrying pedals which enable the heel pressure to be applied between the
cranks and project considerably in advance of the front crank, substantially as
and for the purposes set forth.
2. In a driving gear of the kind referred to in the preceding claim, the employ-
ment of means for ensuring the turning of the cranks in unison, substantially as
described.
3. My improved driving gear for cycles, constructed and operating substan-
tially as hereinbefore described with reference to Figures 1 to 4, or to Figures 5
to 7 of the drawings, for the purposes specified.
D 0141...
1900
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, & 5A, Market Street, Nottingham,
Agent for the Applicant.