Improvements in and connected with Variable Speed Belt Driving Gear.
Year: 1897

page_text: Date of Application, 5th Nov., 1897
Complete Specification Left, 5th Aug., 1898-Accepted, 10th Sept.,
1898
PROVISIONAL SPECIFICATION.
Improvements in and connected with Variable Speed Belt Driving
Gear.
I, JOHN GEORGE AULSEBROOK KITCHEN, of 44, Albert Road, Alexandra Park,
Manchester, in the County of Lancaster, Mechanician, do hereby declare the
nature of this invention to be as follows:
This invention relates to belt driving gear and has for its object the imparting
of a variable speed to the driven shaft from a driving shaft revolving at a uniform
speed. This object is obtained by an improved construction of a pulley the
diameter of which can be increased or reduced in combination with means for
effecting such increase or reduction and for keeping the belt tight on the pulleys.
The rim of the improved pulley is formed by a number of equal links con-
nected in pairs by pivots at their centre and having the ends of each pair of links
connected by pivots to the ends of the adjacent pairs of links so as to form a
circular or endless lazy tongs which forms a rim that can be expanded or con-
tracted in diameter, becoming narrower or wider at the same time.
The pivots
connecting the ends of the links are preferably extended on the outside to form
checks for preventing the belts from slipping off the pulley.
The expansible rim thus formed is provided with means for expanding and
contracting the same, which may be arranged in any suitable way. Preferably
the central pivots of the links composing the rim or some of them are each formed
on the inside of the rim with a lug or lugs to which two links are hinged spreading
outwards and each connected at its other end to a bush sliding on the shaft but
rotating with the same, the links forming toggle joints and the rim being expanded
or contracted by drawing the bushes together or moving them further apart.
This may be done by any suitable ordinarily used means for shifting the position
of sliding bushes on a shaft. For instance, if the changes in the diameter are
only to be made when the shaft is at rest, a rack may be attached to each bush,
the racks engaging on opposite sides with a pinion mounted on a stud on the
shaft, by turning which pinion the bushes are pushed apart or drawn together and
held in position by backing the pinion. Or instead thereof a right and left
handed screw spindle threaded through corresponding nuts formed or attached on
the bushes and held in a bracket fixed to shaft may be used. If the change in
diameter of the pulley is to be effected while it is running, the bushes may be
formed with circular grooves into which the forked ends of levers or slides engage
and these be drawn together by any suitable means. Or instead thereof a right
and left handed screw spindle may be arranged as aforesaid and a pinion fixed
upon the end of the same gearing on one side with an external spur-wheel mounted
loose on the shaft and on the other side with an internal spurwheel likewise loose
on the shaft, and the bushes of said spur-wheels fitted with brake pulleys, so that
either of them can be prevented from rotating while the shaft continues to revolve
and the screw-spindle thus be turned in one or the other direction.
As the length of the belt remains unaltered while the pulley is expanded or con-

page_text: tracted, provision must be made either for altering the distance of the driving and
driven shaft correspondingly, or for tightening the belt, which may be done in
any convenient manner suitable to the purpose for which the variable speed
driving is applied. In the case of a motor car for instance, the engine and crank-
shaft may be mounted on a swing frame pivotted at the end opposite to the crank-
shaft end and pulled by a weight or spring so as to keep the belt tightened. Or a
belt tightening pulley acting on the belt between the two shafts and weighted by
a weight or spring, may be employed.
Dated this 4th or of Noraha 1807
R. J. URQUHART,
57, Barton Arcade, Manchester,
Consulting Engineer & Patent Agent.
COMPLETE SPECIFICATION.
Improvements in and connected with Variable Speed Belt Driving
Gear.
I, JOHN GEORGE AULSEBROOK KITCHEN, of 44, Albert Road, Alexandra Park,
Manchester, in the County of Lancaster, Mechanician, 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 belt driving gear and has for its object the imparting
of a variable speed to the driven shaft from a driving shaft revolving at a uniform
speed. This object is obtained by an improved construction of a pulley the
diameter of which can be increased or reduced, in combination with means for
effecting such increase or reduction and for keeping the belt tight on the pulleys.
The rim of the improved pulley is formed by a number of equal links con-
nected in pairs by pivots at their centre and having the ends of each pair of links
connected by pivots to the ends of the adjacent pairs of links so as to form a
circular or endless lazy tongs which forms a rim that can be expanded or con-
tracted in diameter, becoming narrower or wider at the same time.
The pivots
connecting the ends of the links are preferably extended on the outside to form
checks for preventing the belts from slipping off the pulley.
The expansible rim thus formed is provided with means for expanding and
contracting the same, which may be arranged in any suitable way. Preferably
the central pivots of the links composing the rim or some of them are each formed
on the inside of the rim with a lug or lugs to which two links are hinged spreading
outwards and each connected at its other end to a bush sliding on the shaft but
rotating with the same, the links forming toggle joints and the rims being expanded
or contracted by drawing the bushes together or moving them further apart.
This may be done by any suitable ordinarily used means for shifting the position
of sliding bushes on a shaft.
As the length of the belt remains unaltered while the pulley is expanded or con-
tracted, provision must be made either for altering the distance of the driving and
driven shaft correspondingly, or for tightening the belt, which may be done in
any convenient manner suitable to the purpose for which the variable speed
driving is applied. In the case of a motor car for instance, the engine and crank-
shaft may be mounted on a swing frame pivotted at the end opposite to the crank
shaft end and pulled by a weight or spring so as to keep the belt tightened. Or a
belt tightening pulley acting on the belt between the two shafts and weighted by
a weight or spring, may be employed.

page_text: On the drawing appended hereunto
Figure 1 shows a side view and Figure 2 a vertical section of a part of a pulley
constructed according to my invention, with one arrangement of mechanism for
enlarging and reducing the diameter of the pulley. Figure 3 a plan of part of
the rim developed; Figure 4 a cross section of the same and view of the pivot to
which the arms are attached, on an enlarged scale. Figures 5 and 6 shew a
section and plan view of a modified arrangement for altering the diameter. The
rim A of the improved pulley is formed by a number of equal links a a connected
by pivots b at their centres to other links a¹ a¹ of the same length, so as to form
pairs a a¹ of links, the ends of the link a of each pair being connected to the ends
of the links a¹ of each adjacent pair of links by pivots b as shewn by Figures 3
and 4, so as to form a circular or endless lazy tongs, which forms the rim of the
belt pulley. The pivots 61 connecting the ends of the links are preferably
extended as shewn by Figures 1 and 2 on the outside of the rim so as to form
checks for preventing the belts from slipping off the pulley.
Some of the central pivots of the links composing the rim for instance six
of them, are formed on the inside of the rim with projecting lugs or crossheads 68,
Figures 1, 2 and 4, to which two links c c are hinged, which spread outwards and
are respectively connected at their other ends to lugs d on two bushes D D¹ sliding
on the shaft e on long keys or otherwise arranged so as to be able to slide on the
shaft and be rotated with the same. The links c c form the arms of the pulley
and toggle joints, the rim A being expanded by moving the bushes D D towards
each other and contracted by moving them further apart.
Figures 1 and 2 represent an arrangement of mechanism for effecting these
movements of the bushes D D1 while the shaft e is rotating. Each bush is formed
with a lug into which a nut is fixed, and a screw spindle f formed with a right
hand thread at one end and a left hand thread at the other is threaded through
these nuts. The spindle is formed with two collars f¹ fl arranged on either side
of a lug on a boss g, which is fixed in position on the shaft e. Each end of the
screw spindle carries a toothed pinion h, that on the left side gearing with an
internal spur wheel formed on the rim of a brake pulley and that on the right
side gearing with an external spur wheel formed on the boss of a second brake
pulley. The brake pulleys and are mounted loose upon the shaft e between
fixed collars el. When the brake pulley i is held fast by a brake, which may be
of any ordinarily used kind, while the shaft e with the expansible pulley and its
attachments is rotating backwards, the left hand pinion h will be rotated for-
wards on its axis and turn the screw spindle f forwards, thereby drawing the
bushes D and D₁ nearer to each other and expanding the rim A of the pulley.
When the right hand brake pulley is held fast while the shaft e rotates back-
wards, the right hand pinion h will be rotated backwards on its axis and turn the
screw spindle in the same direction thereby moving the bushes D and D¹ farther
apart and reducing the diameter of the rim A.
Instead of this arrangement of a screw spindle rotated in different directions
by means of two pinions gearing respectively with an external and an internal
spurwheel attached to brake pulleys, for expanding or contracting the driving
pulley while the shaft is rotating any other suitable arrangement for this purpose
may be employed. For instance, the bushes D and D' may be formed with
circular grooves into which the forked ends of two levers fulcrumed on fixed centres
engage, and these levers are drawn together and pushed apart by means of a screw
spindle with a right and left hand thread, or by equivalent arrangements of links
and levers.
When the diameter of the pulley only requires altering while the shaft is at
rest, the arrangement described with reference to Figures 1 and 2 may be used
with omission of the brake pulleys, spurwheels and pinions, the ends of the screw
spindle or one of them being formed with a square or its equivalent for applying
a spanner and turning the spindle thereby. A spring pawl or detent may be
applied for holding the spindle in its positions.

page_text: Figures 5 and 6 represent another simpler arrangement for expanding and con-
tracting the rim of the belt pulley while at rest. The bushes D and D₁ to which
the arms of the pulley are connected have in this case racks 7 and 11 respectively,
fixed to them, which engage with a pinion m mounted on a stud n screwed into
the shaft e. The pinion is formed with a projection m¹ formed so that a spanner
can be placed on it for turning the pinion and thereby drawing the bushes
together or moving them apart. A claw n¹ is placed upon a squared part of the
stud n and seizes into the teeth of the pinion and thereby locks the same and the
bushes in their respective positions, this claw being of course lifted off while
the adjustment is made.
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. The construction of the rim of a belt pulley of links connected together so
as to form an endless lazy tongs by the elongation or contraction of which the
diameter of the pulley is increased or reduced, substantially as herein before
described and illustrated by the drawings.
2. The construction of a belt pulley with a rim composed of links connected
together so as to form an endless lazy tongs in combination with means for
expanding and contracting the rim and for keeping the belt tight on the pulley,
substantially as hereinbefore described.
3. The construction of a belt pulley with a rim composed of links connected
together so as to form an endless lazy tongs and arms formed each of two links
or their equivalent hinged at one end to one of the centre pivots of the links
forming the rim and at the other end to two sliding bushes respectively so as to
form a toggle joint, in combination with means for drawing the bushes together
and moving them apart, substantially as herein before described and illustrated by
the drawings and for the purpose set forth.
4. In combination with a belt pulley constructed as specified in the preceding
claim, the arrangement of a screw spindle with a right and left hand thread,
pinions, spur wheels and brake pulleys for shifting the bushes and enlarging or
reducing the diameter of the pulley while it is rotating substantially as herein
before described with reference to Figures 1 and 2 of the drawings.
5. The arrangement of racks and pinion for shifting the bushes of a belt pulley
constructed as specified in the third claim, substantially as herein before described
with reference to Figures 5 and 6 of the drawings.
Dated this 4th day of August 1898.
R. J. URQUHART,
57, Barton Arcade, Manchester,
Harrington Chambers, 24, North John Street, Liverpool,
Consulting Engineer and Patent Agent.