Improvements in Adjustable Speed Gear.
Year: 1895

page_text: Improvements in Adjustable Speed Gear.
I, FREDERICK RICHARD SIMMS, of 49, Leadenhall Street, in the City of
London, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in adjustable speed gear designed for use
in connection with gas or petroleum motors, lathes, and other machinery.
In carrying out my invention I provide on the driving or motor shaft and on the
shaft to be driven a boss having a projecting rim around and in openings in which
are arms arranged radially and forked or grooved at their outer ends, the said
arms in each boss forming together an interrupted grooved wheel or pulley, a
suitable driving belt or chain connecting the two pulleys together. The arms of
each pulley are adapted to be extended radially by means of a cone sliding on
the shaft carrying the pulley, suitable mechanism such as a rocking lever being
employed which when operated in either direction moves one cone to extend the
arms of one pulley thereby increasing its size and withdraws the cone of the other
pulley so that the arms of the latter are caused to collapse and reduce its size
under the increased tension of the belt or chain due to the increase in size of the
other pulley.
In cases where the shafts are close I dispense with the driving belt or chain and
place the wheels in contact so as to drive by friction the ribs on one wheel
being arranged to engage with the grooves of the other wheel and, in order that a
good frictional contact shall be maintained when the interruptions in each wheel
come opposite, I construct the wheels with the interruptions diagonally.
In some cases I connect the two wheels by a third or intermediate wheel
pivoted on a lever and brought into contact with the other two wheels by suitable
means such as by a worm. By moving this intermediate wheel backwards or
forwards by means of the lever I cause the one wheel to increase in diameter and
the other to decrease in the same proportion. The rim of this intermediate wheel
is advantageously provided with a tyre of india rubber or rubber composition or
with a pneumatic tyre whereby good friction or close contact with little or no noise
when running is obtained.
Date LL
ג
1008
improvements in Adjustable Speed Gear.
I, FREDERICK RICHARD SIMMS, late of 49, Leadenhall Street, now of
Amberley House, 12, Norfolk Street, Strand, 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 :-
This invention relates to improvements in adjustable speed gear designed for use
in connection with gas or petroleum motors, lathes, and other machinery.

page_text: In carrying out my invention I provide on the driving or motor shaft and on the
shaft to be driven a boss having a projecting rim, around and in openings in which
are arms arranged radially and forked or grooved at their outer ends, the series of
arms in each boss forming an interrupted grooved wheel or pulley. A suitable
driving belt or chain connects the two pulleys together and the arms of each pulley
are adapted to be extended radially by means of a cone sliding on the shaft
carrying the pulley. Suitable mechanism, such as a rocking lever, is also provided,
which, when operated in either direction, moves one cone so as to extend the arms
of one pulley thereby increasing its size, and also withdraws the cone of the other
pulley so that the arms of the latter are caused to collapse and reduce its diameter
under the increased tension of the belt or chain due to the increase in size of the
first pulley.
In cases where the shafts are close together, I dispense with the driving belt or
chain and place the wheels in contact so as to drive by friction, the ribs on one
wheel being arranged to engage with the grooves of the other wheel and, in order
that a good frictional contact shall be maintained, I construct the wheels with the
interruptions diagonally.
In some cases I connect the two wheels by a third or intermediate wheel
pivoted on a lever and brought into contact with the other two wheels by suitable
means such as by a worm or screw. By moving this intermediate wheel back-
wards or forwards by means of the lever I cause the one wheel to increase in
diameter and the other to decrease in the same proportion. The rim of this
intermediate wheel is advantageously provided with a tyre of india rubber or
rubber composition or with a pneumatic tyre whereby good frictional contact with
little or no noise when running is obtained.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings, in which-
Figure 1 is a sectional elevation of adjustable speed gear constructed according
to my invention:
Figure 2 is a sectional plan of the same :
Figure 3 is a plan of one of the pulleys and cones with a modified form of radial
arms:
Figure 4 is a vertical section of adjustable speed gear with the diagonally
arranged interruptions between the arms :
Figure 5 is a front elevation of the same :
Figure 6 is a side elevation of adjustable speed gear with the diagonally arranged
interruptions between the radial arms; and,
Figure 7 is a front elevation of the same:
Figure 8 is a sectional plan of adjustable speed gear constructed according
to my invention and shewing the two pulleys connected by an intermediate friction
wheel:
Figure 9 is an elevation of the same.
Similar letters of reference indicate similar or corresponding parts in the several
figures.
a is the driving and 6 the driven shaft, c, c are the bosses mounted on the two
shafts a and b and c, c' are the projecting rims of the same. , are the openings
or holes arranged radially round the projecting rims c¹ of each boss and d, d are
the arms inserted in the said openings. These arms d are forked or grooved at
their outer ends as shewn at d' so that the series of radial arms forms a wheel the
periphery of which is interrupted at intervals as shewn clearly at e, e Figures 1
and 9.
fare the cones adapted to slide on the two shafts a and b and provided with
grooves f,, in which the inner ends of the radial arms d engage.
In Figure 3 the radial arms d are shewn bent back in front of one of the faces
of the bosso and the groove d¹ formed in the bent back ends of the said arms.
In Figure 1 the two pulleys are shewn connected by means of a belt or chain g.
With this construction it will be obvious that, when the cone f of the driving

page_text: shaft a is pushed towards the interior of the boss c and the boss on the driven
shaft pushed outwards from its boss by suitable means such as a rocking lever,.
the radial arms d of the boss on the driving shaft a will be forced outwards and
the arms of the boss on the driven shaft b will be collapsed by the tension of the
belt or chain g so that the said driven shaft 6 will be rotated at a less speed than
before. When the cone f of the driven shaft bis pushed inwards a contrary
effect is produced, that is to say, the speed of rotation of the said driven shaft b
increases.
In Figures 4, 5, 6, and 7 the belt or chain g is dispensed with as the shafts a
and 6 are near together. In the arrangement shewn in these figures only the
driving shaft a is provided with my collapsable pulley the driven shaft 6 being
provided with a pulley or wheel c grooved internally (as shewn in Figures 4 and 5).
or externally (as shewn in Figures 6 and 7) and in the grooves of which the-
outer ends of the radial arms d, d engage. The interruptions or spaces e between
the successive arms are not parallel to the shaft but are at an angle to the
same so that a continuous contact is obtained between the driving and driven.
pulleys.
In the arrangement shewn in Figures 8 and 9 the two adjustable pulleys are
connected by means of the intermediate wheel the said wheel being preferably
provided with a tyre of india rubber or rubber composition or a pneumatic tyre so
as to provide a good frictional contact between it and the two pulleys. In these
figures i is a rocking lever engaging with the two cones f, fon the shafts a and b, and it
is a toothed sector connected to the same which sector i geare with a rack connected
to a guide pivoted at . j is a screwed spindle adapted to be turned in the said
guide through the medium of the hand wheel and the scrowed end of which
passes through, or engages with, an internally screwed slide to which the inter--
mediate wheel his connected. With this construction, by turning the rod ; on the
pivot the rack rotates the sector ¹ so that one of the cones fis pushed inwards
and the other outwards whilst the intermediate wheel h is at the same time moved
to the right or the left to enable one pulley to expand and the other to contract in
diameter to the desired extent. As the intermediate wheel is, as above.
described, pivoted to the slide it will be obvious that by rotating the screwed
spindle the said wheel h can be moved out of contact with the two pulleys when.
desired.
j
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. Adjustable speed gear for varying the ratio of the speeds of rotation of driving
and driven shafts, consisting of a boss mounted on the driving or driven shaft.
(or on both shafts) and having openings or holes in which a number of arms forked
at their outer ends are radially arranged so as to form an interrupted pulley, and
of a cone adapted to slide ou the said shaft and engage with the inner ends of the
said radial arms so as to increase or diminish the diameter of the pulley formed.
by the said arms, substantially as described.
2. In adjustable speed gear of the kind described in Claim 1 connecting the
pulleys on the driving and driven shafts by a belt, by an intermediate wheel or by
direct contact, substantially as described and illustrated.
3. The combinations and arrangements of parts forming the improved adjustable
speed gears herein before described and illustrated in Figures 1, 2 and 3; 4 and 5 ;.
6 and 7; and 8 and 9 respectively of the accompanying drawings.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.