IMPROVE- MENTS IN VELOCIPEDES PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER MACHINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Lisle Henry Curtois at the Office of
the Commissioners of Patents on the 19th May 1882.
LISLE HENRY CURTOIS, of Loughborough in the County of Leicester "IMPROVE-
MENTS IN VELOCIPEDES PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO
OTHER MACHINES
"
My invention relates chiefly to velocipedes and has for its main object to provide
means whereby the rider is enabled to change the relative velocities of the treadle-
shaft and driving-wheels, for the purpose of gaining power, and to effect such
change without requiring to materially decrease the speed and without causing any
jar or shock to the parts of the velocipede.
In carrying the said invention into practice I provide upon the cranked treadle-
shaft a chain-wheel which is free to rotate upon the said shaft and from which
motion may be transmitted by means of a chain to another chain-wheel on the
shaft of the driving-wheels. The chain-wheel on the treadle-shaft may be made
to turn therewith by means of a clutch and is in one with, or connected by means
of a bolt or pin or other suitable means to, a toothed wheel. At one end of the
treadle-shaft is fixed another toothed wheel which carries a pawl or pawls held in
gear with a ratchet-wheel by means of a spring or springs, tho said ratchet-wheel
being fixed upon the treadle-shaft. The said toothed wheels are capable of being
placed in or out of gear with two other toothed wheels fixed upon another shaft,
these operations being effected by means of a lever pivoted in suitable bearings
and carrying, in a bearing at one end of it, the shaft upon which the last named
toothed wheels are fixed. The said toothed wheels are of such proportions that
when they are placed in gear with one another by moving the aforesaid lever, the
wheel carrying the pawls will be driven faster than the ratchet-wheel and when
the aforesaid clutch is disengaged this gear with the chain-wheels will rotate
independently of the treadle-shaft owing to the momentum of the velocipede until
the rider causes the treadle-shaft and the ratchet-wheel attached thereto to
overtake the toothed wheel carrying the pawls which will then gear with the
ratchet-wheel and instead of the chain wheel, and hence the velocipede being
driven directly from the treadle-shaft it will be driven by means of the
intermediate gearing, and the power exerted upon the driving-wheels will thus be
increased.

page_text: If necessary to still further decrease any jar or shock to the parts when the
toothed wheels are brought into gear I employ means whereby the speed of the
toothed wheels may be easily accelerated to the required degree previous to their
being brought into gear. For this purpose I fix small pulleys of suitable diameters
upon the shafts carrying the toothed wheels, and I connect these pulleys by means
of belts which also pass over tightening pulleys arranged in a sliding frame which
may be operated by means of a handle connected to the said frame by a link, or
by means of a cord provided with a spring for effecting the return motion, or by
other suitable means.
The devices for working the lever and clutch are preferably so arranged that
they may be operated by the movement of a handle on one side of the velocipede,
the steering handle being placed at the opposite side. For this purpose the bar to
which the said handle is attached is provided with cams or plates having curved
slots, which are connected by means of pins and links to the aforesaid lever and
also to a bell-crank which works the aforesaid clutch, reciprocating motion being
imparted to the links by the cams and the said slots being so formed that the
lever will first be operated and then the clutch will be disengaged the said handle
being turned half a revolution to accomplish this. By further turning the handle
in the same direction, the lever is first operated and then the clutch is engaged so
as to return to the ordinary gearing, the said handle being prevented from turning
in the opposite direction by means of a small pawl and ratchet-wheel.
The gearing above described may be fitted to either one or both sides of a
velocipede; it may also be adapted to other machines requiring a change from fast
to slow motion without stopping the said machines or injuriously straining them,
and the construction and arrangement of the parts may be varied to suit the form
of velocipede or the description of machine to which the said gearing is to be
applied. The diameters of the toothed wheels may be proportioned according to
the relative change of speed required