Improvements in Apparatus for Varying Speed in the Transmission of Power.
Year: 1896

page_text: Date of Application, 24th Nov., 1896
Complete Specification Left, 25th Jan., 1897-Accepted, 27th Mar.. 1897
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Varying Speed in the Transmission
of Power.
I, JEREMIAH MCCRAITH of The Elms Melton Mowbray in the County of Leicester,
Doctor in Medicine, do hereby declare the nature of this invention. to be as.
follows:-
The apparatus according to this invention consists of an axle carrying a diso. or
drum around which are centered a number of balances or levers each of which is so
shaped at each end that the series of balances or levers form a pulley at each side or
end of the disc or drum for the reception of driving. bands or chains. The ends of
each of the balances or levers are in connection by ribs or arms umbrella-spoke
fashion with a collar or tube capable of sliding on the axle so that the expanding of
one side and contraction of the other are analogous to the opening and closing of two
umbrellas. Thus when the ends of the balances or levers at one side or end of the
drum are moved inwards towards the axle those at the other end are moved outwards:
away from the axle and by the contraction a small pulley is formed and by the
expansion a large pulley. is formed whilst when the balances or levers are parallel
with the sbaft the pulleys formed by each of the series of ends are equal. Driving
bands or chains are passed over the respective pulleys thus formed one band or chain
leading from the motor shaft and the other leading to the axle or the like to be driven.
The axle which carries the aforesaid dise or drum and balances or levers is mounted in
bearings in a frame or support so that the disc or drum axle can be moved transversely
by a screw or other device and when moved in one direction one of the bands or chains
causes the ends of the series of balances constituting one pulley to be moved inward
whilst the other ends constituting the other pulley move outwards and thus the
diameters of the respective pulleys are decreased and increased. By moving the disc
or drum axle in the opposite direction the reverse alteration in the relative diameters
of the pulleys takes place.
Dated this 23rd day of November 1896
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improvements in Apparatus for Varying Speed in the Transmission
of Power.
I, JEREMIAH MC CRAITH of The Elms, Melton Mowbray, in the County of Leicester,
England, Doctor in Medicine, 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:-
This invention has for its object to provide a simple and efficient arrangement by
means of which speed can be very readily altered in the transmission of power :-
According to this invention balances, or levers, are centered to a support in a

page_text: circular series, the respective ends of the series, constituting pulleys over which bands
or chains, can be passed. When the ends of the balances, or levers, forming one of the
pulleys, are moved towards each other the pulley which they constitute is reduced in
diameter, and, at the same time, as the balances, or levers turn on their centres, the
pulley constituted by the other ends is increased in diameter. The expansion and
contraction may be effected in any suitable way but in order that my invention and the
manner in which it can be practically carried out may be well understood I will describe
an arrangement according thereto with reference to the accompanying drawings.
Figure 1 is a plan and Figure 2 a side elevation of the arrangement..
Figure 3 shews the arrangement forming the pulleys drawn to a larger scale, with
the pulleys of the same diameter.
Figure 4 is a similar view but with one pulley reduced and the other increased in
diameter.
The apparatus consists of an axle A, having secured to it a disc, or drum, B, in
slots around which are centered at e a number of balances, or levers, C, each of which
is so shaped at each end that the series of balances, or levers, form a pulley at each
side, or end, of the disc, or drum, for the reception of driving bands, or chains. The
ends of each of the balances, or levers, C, are in connection by ribs, or arms, E,
umbrella-spoke fashion, with a collar, or tube, a, capable of sliding on the axle A,
so that the expanding at one side and contraction at the other are analogous to the
opening and closing of two umbrellas. Thus when the ends of the balances, or
levers, C, at one side, or end, of the drum, are moved inwards towards the axle A,
those at the other end are moved, outwards, away from the axle A, and by the
contraction a small pulley is formed and by the expansion a large pulley is formed
as shewn in Figure 4, whilst, when the balances, or levers, C, are parallel with the
shaft, as shewn in Figure 3, the pulleys are equal. Driving bands, or chains, D, are
passed over the respective pulleys thus formed; one band, or chain, leading from a
pulley, on the motor shaft F and the other leading to a pulley g, on the axle G, or
the like to be driven. The requisite alteration in the diameters of the pulleys can be
effected as follows:-The axle A, which carries the aforesaid disc, or drum, B, and
balances, or levers, C, is mounted in bearings, in a frame, or support, H, so that the
disc, or drum, axle A, with the drum and balances, or levers, carried by it can be
moved transversely upon the support I, by a screw K, or other device, operated by a
handle at any convenient situation; transmission gear intervening, if necessary, and,
when moved in one direction, one of the bands, or chains, causes the ends of the series
of balances or levers constituting one pulley to be moved inward whilst the other ends
constituting the other pulley move outwards and thus the diameters of the respective
pulleys are decreased and increased respectively and the speed is regulated accordingly.
By moving the disc, or drum axle in the opposite direction the reverse alteration in
the relative diameters of the pulleys takes place. My invention can be used for
varying speed in motor cars, and locomotive, portable, or stationary, machinery
generally.
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. In, or for, mechanism for varying speed in the transmission of power, a duplex
pulley constituted by a circular series of balances, or levers, centered to a carrier so
that when their one ends are moved inwards, or towards, each other, the pulley
constituted thereby is reduced in diameter, the pulley constituted by their other ends
being increased in diameter; substantially as herein before described.
2. In, or for, mechanism for varying speed in the transmission of power, a duplex
pulley constituted by a circular series of balances, or levers, centered to a carrier
carried by an axle upon which are slidable sleeves, connected by ribs to the said
balances, or levers, so that when the one ends of the said balances, or levers, are
moved inwards, or towards each other, and the sleeve appertaining thereto is moved
outwards along the axle the other ends of the series of balances, or levers, are

page_text: moved outwards or away from each other, and the sleeve appertaining thereto is
moved inwards along the axle; substantially as herein before described.
3. A mechanism for varying speed in the transmission of power, consisting of
duplex pulleys constituted by a circular series of balances, or levers, centered around
a support on an axle and bands, or chains, passing over the respective pulleys so
formed, and means for moving the said axle laterally, so as to contract the one pulley
and cause the other to expand; substantially as hereinbefore described and illustrated
by the accompanying drawings.
Dated this 25th day of January 1897
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.