Improved Driving-mechanism for Velocipedes.
Year: 1893

page_text: Date of Application, 28th Jan., 1893
Complete Specification Left. 28th Nov.. 1893-Accepted. 30th Dec., 1893
PROVISIONAL SPECIFICATION.
Improved Driving-mechanism for Velocipedes.
I, BENJAMIN JOSEPH EDWARDS, of The Grove, Hackney, in the County of
Middlesex, Manufacturer do hereby declare the nature of this invention to be as
follows:-
This invention relates to improved driving-mechanism for velocipedes.
According to my said invention I secure a main crank as heretofore ou each end
of the ordinary crank shaft, but instead of attaching the pedals directly thereto I
provide for driving each said main crank through the intervention of an auxiliary
crank which turns about an axis that is not in the same line as the main crank
shaft. The auxiliary crank is connected to the main crank by a pin and slot or
other sliding connection.
Oue convenient mode of carrying my invention into practice is to provide outside
the main crank a bearing bracket for the auxiliary orank which auxiliary crank is
placed on the inner side of the said boaring bracket eccentric to the main crank
and is coupled to the said main crank by a sliding connection such as a pin. and
slot. Outside the said bearing bracket is an ordinary pedal orank fixed on the
same spindle as the inner auxiliary crank and may be fixed parallel therewith or at
any convenient angle thereto either in rear or in advance thereof.
By this construction of driving-mechanism I enable the rider to apply more
power during the down stroke of the pedal and thus I facilitate the mounting of
steep gradients which could not be climbed by the ordinary-mechanism the pedals
not being long enough to give the required propelling power. Owing moreover to
the increased leverage obtained by this driving-mechanism, the driving whool can
be geared higher than heretofore, thus giving greater speed.
Dated this 28th day of T1902
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Driving-mechanism for Velooipedes.
1, BENJAMIN JOSEPH EDWARDS, of The Grovo, Hackney, in the County of
Middlesex, Manufacturer, 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 driving-mechanism for velocipedes, and comprises the
improvements hereinafter set forth.
The chief feature of my said invention relates to the provision of auxiliary
driving crauks for rotating the ordinary crank shaft, said auxiliary oranks being
constructed and arranged to turn about an axis that is not in the same line as the
ordinary crank shaft. The auxiliary cranks are connected to the ordinary or main
cranks by a pin and slot or equivalent sliding connection.
In the accompanying drawings I have shown my invention applied to a rear-
driving chaiu-geared bicycle.
Figure 1 is a side view of as much of the bicycle as is necessary to illustrate my
invention.

page_text: Figure 3 is a sectional plan of the frame on the line y, y Figure 1.
Figure 4 is a view of a chain wheel with a slotted arm to serve as a orank.
Figure 5 is a central section of the same.
Like letterà denote corresponding parts in all the figures.
I have shown a diamond frame constructed substantially as heretofore, but
having provision made for supporting the auxiliary driving cranks. A, A are the
main crauks on the ends of the chain wheel spindle B which is carried by the
bottom bracket C as heretofore. Said cranks A, A are slotted at a as shown.
The pedal cranks D, Dare secured to short spindles mounted to turn in bearings d, d
formed at the junction of and supported by rods E, F which are rigidly connected
respectively to the members G, H of the frame. The rods which mainly
operate as stays may in some instances be dispensed with. Said rode E, F are
preferably made tubular, and may be made of twisted steel strips or otherwise to
ensure great strength and rigidity. On the inner ends of the pedal crank spindles
are firmly secured the auxiliary cranks I, 1 the pins of which work in the slots a of
the main cranks A. Said pins may be furnished with rollers to reduce the friction.
The axis about which the pedal cranks turn is not in line with that about which
the main cranks turn but is separated therefrom by say 1 or 2 inches more or less
as may be desired. There results from this construction a variable leverage,
decreasing from a maximum when the descending pedal crank is approximately in
the position shown in Figure 1, to a minimum when the said pedal crank has turned
through about half a revolution. I do not confine myself to any particular anglo
between the auxiliary cranks and the pedal cranks, but I prefer to so fix said
cranks in relation to each other that the leverage is greatest when the pedal is
desconding through that portion of the stroke where the power can be most
effectively applied. The auxiliary crank need not be longer than is just sufficient
to properly clear the boss of the main crank.
In order that the pedal oranks may not be both on their dead centres at the same
time with respect to downward thrusts I make the slots in the main cranks A
tangential, that is to say, not radial. Moreover said slots are inclined forward or
in the direction in which the cranks rotate. By this construction each pedal crank
is caused to pass in turn its top dead centre before the other pedal crank arrives at
its bottom dead centre. It will thus be seen that the rider will always be able to
apply a downward thrust to one or other of the cranks that will be effective in
propelling the machine whatever the position of the cranks may be. The dead
centre that exists in ordinary machines is thus virtually done away with. I may
provide the cranks A with radial slots, but these are not so advantageous as the
non-radial slots just described.
It is obvious that I may diapense with the main crank next the chain wheel, and
make use of the chain wheel itself as the crank by slotting one arm of the wheel as
shown in Figures 4 and 5. This enables the pedals to be brought nearer together.
Moreover the chain wheel may be dished as shown in Figure 5 to receive the
auxiliary crank and so enable the pedals to be brought still closer together.
In lieu of the pin and slot connection above described, I may employ any other
suitable form of connection which allows of the required sliding movement.
By this construction of driving mechanism I enable the rider to apply more.
power during the down stroke of the pedal and thereby facilitate the mounting of
steep hills which could not be climbed by riders using the ordinary driving
gear heretofore in use. Further by reason of the fact that both pedal oranks
are not on the dead contre at the same time as above described the rider can
always apply propelling power which as far as I am aware has not hitherto
heen possible. Moreover owing to the increased leverage obtained, the driving
wheel can be geared higher than is possible with ordinary driving mechanism
and thus greater speed can be obtained. My improvements can obviously be
applied to ordinary as well as to chain-driven bicycles, and also to velocipedes
having three or more wheels. All the bearings can be furnished with balls to
reduco friction in the well-known manner.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. For a velocipede, driving-mechanism comprising pairs of crauks which are
constructed to turn about different centres and are connected together by a.
sliding connection, for the purpose specified.
2. The combination, with the slotted main cranks, of the auxiliary cranks
connected therewith, and the pedal cranks for rotating the said auxiliary cranks,
substantially as, and for the purpose, specified.
3. Providing the main oranks with non-radial slots substantially as, and for
the purpose, specified.
4. The modification wherein the chain wheel is slotted to take the place of one
of the main oranks, substantially as described.
5. For a velocipede, driving mechanism constructed and arranged substantially
as described with reference to the drawings, and operating as, and for the purposes,
specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.