Improvements in Driving Gear for Bicycles, Tricycles, and the like.
Year: 1898

page_text: Improvements in Driving Gear for Bicycles, Tricycles, and the like.
I, DOWNES ELLAND NORTON, of "Laurel Dene," Hampton Hill, in the County
of Middlesex, Gentleman, do hereby declare the nature of this invention to be as
follows:-
My invention has reference to improvements in driving gear for bicycles,
tricycles and the like, and has for its object to enable the rider to obtain increased
driving power on the down stroke of the pedal crank. With my invention I
employ two sets of chain wheels, and two chains, one on either side of the
machine.
I will describe my invention with reference to one of the driving chain wheels,
it being understood that the same applies to the other.
I mount the chain wheel on a projecting spindle or shaft which is a fixture
in the barrel of the ordinary gear wheel bracket and has no rotary motion. This
spindle or shaft is preferably formed in one with or fixed concentrically in a sleeve
which is sweated, keyed or otherwise rigidly fixed in the barrel of the bracket,
the chain wheel being also preferably mounted on another sleeve or socket which
works in the above mentioned fixed socket in the barrel of the bracket said
movable socket being mounted on suitable ball bearings. On the projecting end of
the above mentioned fixed spindle or shaft in the bracket barrel is keyed one end
of a short arm or crank, to the other end of which the ordinary pedal crank is
centred the latter being mounted on suitable ball bearings. Formed in one with
or attached to the chain wheel is a slotted projection on which works a friction
wheel at the pedal end of the crank said wheel being preferably mounted on a
projection of the pedal and spindle and running on a ball bearing.
The action of my invention is as follows:-
Assuming the centre line of the pedal crank to be in a direct horizontal line
with the axis of the chain wheel in the downward stroke or forward position of
said crank, in this position the friction roller on the pedal end of said crank is
approximately at the extreme outward end of the slotted path in the projection
on the chain wheel in which it travels during the revolution of the crank and
chain wheel, consequently at this point in the downward stroke of the crank the
greatest leverage is obtained. As the pedal crank descends the friction wheel
at the pedal end thereof moves along the slotted path towards the centre of the
chain wheel reaching its nearest point to the centre of the chain wheel when
the centre line of the pedal crank is in a direct line, or approximately so, with
the centre of the chain wheel in the upward or backward stroke of the pedal
crank. On the further upward movement of the pedal crank the friction roller
at the pedal end thereof again commences to move away from the centre of the
chain wheel, the friction wheel on the end of the pedal spindle travelling as before
mentioned in the slotted path in the projection on the chain wheel, forming the
connection between the crank and chain wheel whereby the latter is driven.
As a modification, in lieu of the herein before-mentioned slotted projection on
the chain wheel, I provide a solid projection or arm having a cross-piece at the

page_text: end carrying two friction rollers between which the pedal crank works in a similar
manner to that described with reference to the slotted projection. It will be readily
understood that my invention as above described is equally applicable to chainless
cycles.
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
Agent for the said Applicant,
70 and 71, Palace Chambers, Westminster, S.W.
I, DOWNES ELLAND NORTON, of "Laurel Dene," Hampton Hill, in the County
of Middlesex, Gentleman, 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 has reference to improvements in driving gear for bicycles,
tricycles and the like and has for its object to enable the rider to obtain increased
driving power on the down stroke of the pedal crank. With my invention I
employ two sets of chain wheels, and two chains, one on either side of the
machine.
I will describe my invention with reference to one of the driving chain wheels,
it being understood that the same applies to the other, reference being made to
the accompanying drawing in which Figure 1 is a side view of my invention as
applied to a safety bicycle, the inner dotted circle being the path followed by the
pedal in the revolution of the crank, and the outer circle being the path followed
by the end of the slotted projection or arm on the chain wheel hereinafter
referred to. Figure 2 is a front view of same, partly in section.
The same letters refer to the same parts in the two figures.
I mount the chain wheel on a projecting spindle or shaft a which is a fixture
in the barrel b of the ordinary gear wheel bracket and has no rotary motion.
This spindle or shaft a is preferably formed in one with or fixed concentrically
in a sleeve c which is sweated, keyed or otherwise rigidly fixed in the barrel b of
the bracket, the chain wheel d being also preferably mounted on another sleeve
or socket e which works in the above mentioned fixed socket or sleeve c in the
barrel of the bracket said movable socket e being mounted on suitable ball bear-
ings. On the projecting end of the above mentioned fixed spindle or shaft a in
the bracket barrel is keyed one end of a short arm or crank f to the other end
of which the ordinary pedal crank g is centred the latter being mounted on suit-
able ball bearings as shown. Formed in one with or attached to the chain wheel d
is a slotted projection h on which works a friction wheel at the pedal end of
the crank said wheel j being preferably mounted on a projection of the pedal
spindle and running on a ball bearing.
The action of my invention is as follows:
Assuming the centre line of the pedal crank g to be in a direct horizontal line
with the axis of the chain wheel d in the downward stroke or forward position of
said crank, in this position the friction roller j on the pedal end of said crank
is approximately at the extreme outward end of the slotted path h¹ in the pro-
jection on the chain wheel d in which it travels during the revolution of the
crank and chain wheel, consequently at this point in the downward stroke of the
crank the greatest leverage is obtained. As the pedal crank g descends the
friction wheel at the pedal end thereof moves along the slotted path h¹ towards

page_text: the centre of the chain wheel d reaching its nearest point to the centre of the
chain wheel when the centre line of the pedal crank is in a direct line, or approxi-
mately so, with the centre of the chain wheel in the upward or backward stroke
of the pedal crank. On the further upward movement of the pedal crank g the
friction roller at the pedal end thereof again commences to move away from the
centre of the chain wheel, said friction wheel j on the end of the pedal spindle
travelling as before mentioned in the slotted path h in the projection h on the
chain wheel, forming the connection between the crank and chain wheel whereby
the latter is driven.
As a modification, in lieu of the herein before-mentioned slotted projection h
on the chain wheel, I may provide a solid projection or arm having a cross-piece
at the end carrying two friction rollers between which the pedal crank g works
in a similar manner to that described with reference to the slotted projection.
It will be readily understood that my invention as above described is equally
applicable to chainless cycles.
As a further modification I may arrange that the herein-before mentioned
short arm or crank may be adjusted as to its length by providing at the ends of
the fixed spindle a recessed or slotted pieces or heads said short arms or cranks
fitting in the recess and being capable of sliding therein, suitable means being
provided for fixing the end of the short arm in the desired position.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed what I claim is:
-
1. In driving mechanism for cycles and the like, the combination of a fixed
spindle or axle, sprocket wheels (or a sprocket wheel) rotatably mounted thereon
said sprocket wheels having slotted projections or arms, short arms or cranks
keyed on said fixed spindle, driving cranks pivoted on said short arms, friction
wheels or projections on the pedal ends of said driving cranks working on the
slotted projections or arms on the sprocket wheels, all arranged and operating
substantially as herein set forth.
41
2 T
1000
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
Agent for said Applicant,
70 and 71, Palace Chambers, Westminster, S.W.