Improved Driving Gear for Velocipedes and other Machinery.
Year: 1898

page_text: 5
PROVISIONAL SPECIFICATION.
Improved Driving Gear for Velocipedes and other Machinery.
We, CHARLES HERBERT SMART, of 9, Old Broad Street, in the City of London.
Clerk, and JOSEPH STODDART, of 9, Old Broad Street, in the City of Ionden,
Engineer, do hereby declare the nature of this invention to be as follows.-
Our invention relates to pedal- or motor-operated variable speed driving gear
for velocipedes and other vehicles or machinery, and has for its principal object to
enable the ratio of the gear to be varied at will, according to the variations in the
resistance encountered (as in climbing hills) and whilst the vehicle or other
machinery is running.
The invention consists essentially in the mechanical combination whereby power
and motion in an inversely variable ratio are transmitted from a vibratory lever,
oscillated by the rider or motor, to the driving wheel or wheels of the vehicle or
to the driving shaft of the machine.
Upon the axis of the driving wheel or shaft is journalled a chain barrel so geared
by ratchet and pawl or other clutch mechanism to said driving wheel or shaft as
to transmit motion to the latter only whilst the barrel is rotated in one direction.
The barrel is so rotated intermittently by the unwinding from it of a chain whose
one end is attached to the periphery of the barrel, the other end being attached to
a variable fixed point. The unwinding of the chain from the barrel is effected by
the action of the vibratory lever on the bight of the chain between the barrel and
the variable fixed point, whilst the rewinding of the chain upon the barrel and
the return stroke of the lever are effected by a spring put in tension by the forward
rotation of the barrel. That end of the lever which engages with the chain as
above described carries a pulley which, lying in the bight of the chain, permits the
latter to run freely under the stroke of the lever.
In order that the ratio of the gear may be varied, the fixed point of attachment
of the chain is so mounted as to be capable of being shifted between the chain
barrel axis and the fulcrum of the vibratory lever, so as to alter the ratio of the
stroke of the lever to the length of chain unwound thereby such change of position
being effected by any convenient means under the control of the rider or driver
or through the agency of automatically governing mechanism.
Any number of sets of driving gear such as herein described may be arranged
to actuate a single shaft. Two sets are employed in the case of a velocipede or
manumotive carriage, and in order that in such case the driving movement of the
one vibratory lever may assist the return movement of the other, the lever may
be so connected as for instance by a cord passing over a pulley, that the driving
stroke of the one may produce the return movement of the other, the pulley being
sunnorted by a spring whereby the slack of the cord (when both levers are returned

page_text: to the position of rest under the action of the chain-barrel springs) may be
taken up.
Dated this 24th day of March 1898.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improved Driving Gear for Velocipedes and other Machinery.
We, CHARLES HERBERT SMART, of 9, Old Broad Street, in the City of London,
Clerk, and JOSEPH STODDART, of 9, Old Broad Street, in the City of London,
Engineer, 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;-
-
Our invention relates to pedal- or motor-operated variable speed driving gear
for velocipedes and other vehicles or machines and has for its principal object to
enable the ratio of the gear to be varied at will, according to the variations in
the resistance encountered (as in climbing hills in the case of a velocipede for
instance) and whilst the vehicle or other machine is running.
The invention consists essentially in the mechanical combination whereby power
and motion may be transmitted in an inversely variable ratio from a vibratory
lever oscillated by the rider or motor, to the driving wheel or wheels of the vehicle
or to the driving shaft of the machine, the variation of the ratio having for effect
to adapt the driving gear to the varying requirements of the work to be done.
The invention is illustrated in the accompanying drawings as applied to the
driving gear of a bicycle from which its application to other pedomotive, to manu-
motive, or power operated machines will be readily understood.
"
As applied to a bicycle, the construction and operation of the driving gear is
as follows: Upon the spindle a of the driving wheel A is journalled at each side
of the wheel hub a chain or cord barrel b, each of the said barrels being so geared
by pawls c and ratchet wheel d (or by other equivalent mechanism preferably of
the silent" feed running ratchet type) to the hub of the driving wheel as to
transmit motion to the latter only whilst the barrel is rotated in the forward
direction. Each barrel is so rotated intermittently by the unwinding from it of a
chain or corde whose one end e¹ is attached to the periphery of the barrel whilst
the other end e is attached to a fixed point on the frame whose position with regard
to the chain barrel and to the fulcrum of the lever by which the chain is operated
may be varied as hereafter described. The unwinding of the chain and the con-
sequent rotation of the barrel are brought about by the action of the vibratory
lever on the bight of the chain or cord which passes over a pulley f¹ at the end
of the short arm of the lever whilst the rewinding of the chain upon the barrel b
and the return stroke of the lever f are effected by a spring coiled within the
barrel and put in tension by the forward rotation thereof. The pulley f¹ which
acts on the bight of the chain, permits the latter to run freely under the stroke of
the lever, the effect of the chain being made fast at its end to a fixed point being
to cause the length of chain unwound to be increased relatively to the travel of the
end of the lever, in a ratio depending on the position of the fixed point e² the effect
being the inverse of a double purchase tackle.
In order that the ratio of the gear may be varied, the fixed point of attachment e²
of the chain is on a slide g so mounted as to be capable of being shifted along
the member h of the machine frame between the chain barrel b and the fulcrum f
of the vibratory lever f so as to alter the ratio of the travel of the lever end to
the length of chain unwound thereby; the adjustment of the slide g being effected

page_text: by any convenient means under the control of the rider. In the example shewn
he necessary movement is effected in the one direction by a hand lever i fulcrumed
at on the machine frame and locked by a ratchet quadrant the said lever being
connected with each slide by a rod g¹ whilst the movement of the slide g in the
opposite direction is caused by a spring j which is put in tension by the action of
the lever i.
g
The lever carries the pedal and in order that the two pedals may make their
stroke alternately, and that the driving movement of the one may assist the return
movement of the other and so ensure a continuous driving impulse, the two pedal
levers may be connected as for instance by a cord attached to each and passing
over a pulley m, the pulley m being supported by a spring n attached to the
frame whereby the slack of the cord may be taken up when the feet are removed
from both pedals at once and the pedals are consequently returned to their position
of rest under the action of their respective chain-barrel springs.
Attached to the bracket which carries pulley m is a brake shoe m' which is
caused to act by pressing both pedals down simultaneously, the brake being
connected to the frame of the machine by a link m² to prevent it being carried
round by the wheel when applied.
In applying the invention to power-driven mechanism, the motor piston may be
supposed to be connected either to the pedal lever or directly to the pulley which
engages with the bight of the driving chain or cord, and any number of such gears
may be applied to actuate the same shaft whilst the variation of the point of
attachment of the driving chain may be under the control of a mechanical governor.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what'.
we claim is:-
1. A driving gear consisting in the combination of a chain or cord whose one
end is made fast to a fixed point, its other end being wound on a spring barrel in
connection by means of running ratchet gear with the wheel or shaft to be driven
and of means of applying power to act on the bight of the chain or cord so as to
increase the ratio of the motion to the power substantially as specified.
2. A variable speed driving gear consisting in the combination of a chain or
cord whose one end is made fast to a fixed point, its other end being wound on a
spring barrel in connection by means of running ratchet gear with the wheel or
shaft to be driven and of means of applying power to act on the bight of the chain
or cord so as to increase the ratio of the motion to the power, the fixed point of
attachment of the chain or cord being variable in position so as to vary the ratio
of the motion to the power, substantially as specified.
3. A cycle driving gear consisting of a pair of spring barrels in running ratchet
connection with the driving wheel or wheels, chains or cords wound on the barrels
and made fast to adjustably situated fixed points, and pedal or hand levers carrying
pulleys to act on the bights of the chains or cords, substantially as and for the
purpose specified.
4. A cycle driving gear consisting of a pair of spring barrels in running ratchet
connection with the driving wheel or wheels, chains or cords wound on the barrels
and made fast to adjustably situated fixed points, pedal or hand levers carrying
pulleys to act on the bights of the chains or cords, means of coupling the levers so
as to ensure their alternate and opposite action, and means of varying the position
of the fixed points for attachment of the chains or cords, substantially as described.
Dated this 93rd day of December 1898.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.