Year: 1899

page_text: I, LOUIS ROTTENBURG, of No. 129, Church Lane, Old Charlton, in the County of
Kent, Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to expansible and contractible pulleys which are either
automatically or constrainedly expansible contractible.
and
or
According to my invention the pulley is provided with a hub made in two
parts, each part having the same axis and each hub part is provided with one
or more pivotted spokes each of which or each set of which is pivotted to and
supports the rim or tread which is made of one or more pieces. As indicated
the rim is or may be made up of one or a number of parts which is or are
flexible and adapted to slide into or over each other or to be in some way capable
of reducing and increasing the size of the periphery of the wheel. One part
of the hub is for example keyed to or in some way constrained to move with
the shaft on which the whole wheel is mounted and the other part of the hub
is allowed entire or partial freedom of movement on the shaft or on the other
part of the hub or both parts are allowed partial freedom of movement on the
shaft. The spokes of one part of the hub slant say in one direction and the
spokes of the other part of the hub slope in the other direction. It follows that
if one part of the hub be constrained to partially revolve independently of the
other part of the hub, the pivotted spokes of one part of the hub will assume
a different position with regard to the spokes of the other part of the hub the
result of which will be that the rim sections will be caused to move further
away from or nearer to the axis of the wheel that is to say the tangential pull
of the belt on the driving pulley tends to reduce the diameter of the latter,
while it also tends to increase the diameter of the driven pulley. The two parts
of the hub may be connected together by a spring for example in which case the
change in diameter on say one wheel (if there be two) will be regulated auto-
matically by the tangential pull on the belt which also communicates the strain
on the spring between the two hub parts and as the one wheel becomes reduced in
diameter for instance, the belt will become slack and as it becomes slack the
other pulley will naturally increase in diameter owing to the constant tendency
of the tangential pull of the belt, above referred to aided by the spring between
the two hub parts to cause the two sets of spokes to produce an enlargement in
the diameter of the driven pulley. The spring of the driving pulley opposes
the contracting action of the belt pull above referred to. A pulley of the kind
described can be used with a pulley of ordinary construction providing that the
slack of the belt be taken up as required in any convenient manner.
making wheels of this description to regulate their respective diameters auto-
matically and in accordance with the resistance experienced I may also construct
wheels or pulleys in which the alteration in diameter is caused constrainedly
or by means entirely outside of the wheel or pulley itself, that is to say I may
vary the relative positions or angles of the spokes on one hub part to those on
the other hub part and consequently the diameter of the wheel by means, for
Instead of

page_text: instance, of a diagonally cut rack actuated by a fork and collar and sliding
axially in one hub part such rack engaging in a diagonally cut pinion con-
centric with and fixed to the other hub part or by means of a wedge or wedges
for example between the spokes of one hub part and the spokes of the other
hub part or in any other convenient manner, there being if desired a spring to
cause one hub part to keep or to tend to keep in a certain position with regard
to the other hub part.
My invention is of special utility for use in connection with motor cars for
varying the speed at which the .car shall run in a simple manner whether such
variation takes place automatically according as the resistance to be overcome
varies or whether the variation of the pulley or pulleys be effected by means
under the control of the driver.
Besides this however my invention is applicable to many purposes where a
variation of speed is required either automatically or constrainedly.
Dated this 9th day of December 1899
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
I, LOUIS ROTTENBURG, late of No. 129, Church Lane, Old Charlton, in the
County of Kent, but now of Patella Works, Paisley, North Britain, 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:-
-
My invention relates to an improved belt gearing and consists of expansible
and contractible pulleys or wheels which are either automatically or constrainedly
or both automatically and constrainedly expansible and contractible or either
expansible or contractible and which may be used for instance, where a variation
in the number of revolutions is required, where the load is constant and the
speed of the driver varies, or where the load varies and it is desired to maintain
the driver at a more or less constant speed.
t
According to my invention the pulley is provided with a hub made in two
parts each part having the same axis and being provided with one or more sets
of pivotted spokes each of which or each set of which is at its outer end pivotted
to and supports or assists in supporting the expanding and contracting rim or
tread which is made of one or more pieces.
As indicated the expanding and contracting rim is or may be made up of one
or a number of parts which is or are flexible or elastic and adapted to slide into
or over each other or to be in some way capable of reducing and increasing the
size of the periphery of the wheel.
When the pulley is intended to revolve in one direction only one of the two
aforesaid parts of the hub is for example keyed to or in some way constrained to
move with the shaft on which the whole wheel is mounted and the other of the two
aforesaid parts of the hub is allowed entire or partial freedom of movement on
the shaft or on the other part of the hub or both parts are allowed partial freedom
of movement on the shaft when the wheel is intended to revolve in both
directions.
The spokes of one part of the hub slant, say, in one direction and the spokes
of the other part of the hub slope in the other direction.
It follows that if one part of the hub be constrained to move independently

page_text: of the other part of the hub the pivotted spokes of one part of the hub will
assume a different position with regard to the spokes of the other part of the
hub the result of which will be that the rim sections will be caused to move
further away from or nearer to the axis of the wheel or in the case where the
rim is formed of a single piece the ends thereof will be caused to overlap more
or less, that is to say, the tangential pull of the belt tends to reduce the diameter
of the driving pulley, while it also tends to increase the diameter of the driven
pulley.
...
The two parts of the hub may be connected together by a spring, for example,
in which case the change in diameter in one say the driving pulley, if there be
two pulleys, will be regulated automatically by the tangential pull on the belt
the said spring between the two hub parts opposing the contracting action of
the belt pull and as this pulley becomes reduced in diameter, for instance, the
other, say the driven wheel, will increase in diameter owing to the constant
tendency of the tangential pull of the belt, above referred to, aided by the spring
between the two hub parts, to cause the two sets of spokes to produce an enlarge-
ment in the diameter of the said driven pulley.
In order to permit of adjusting the spring a worm wheel is for instance freely
mounted on one part of the hub one end of the spring being attached thereto
and gearing therewith is a worm revolving in bearings in the same part of the
hub which worm is controlled from the outside of the pulley. I may thus set
the spring of the pulley so as to suit the most efficient torque of the motor.
An automatically expanding and contracting pulley of the kind described can
be used with a pulley of ordinary construction provided that the slack of the
belt be taken up as required in any well known and convenient manner.
Instead of making pulleys of this description to regulate their respective
diameters automatically and in accordance with the resistance or load experienced
so as to maintain as nearly as may be a constant speed of the motor or driving
pulley whatever the load may be, or on the other hand, with a constant load to
maintain, as nearly as may be, a constant speed of the driven pulley, whatever
the speed of the motor or driving pulley may be, I may also construct wheels
or pulleys in which the alteration in diameter is caused constrainedly or by
means entirely outside of the wheel or pulley itself that is to say I may vary
the relative positions of, or angles between, the spokes on one hub part and
those on the other hub part and consequently the diameter of the wheel when
at rest by means, for instance of a worm mounted in bearings in one part of
the hub and gearing with a worm wheel attached to the other part of the hub
or when in motion by means of a diagonally cut rack, actuated by a fork and
collar and sliding parallel to the axis in one hub part, such rack engaging in
a diagonally cut pinion concentric with and fixed to the other hub part or by
means of a wedge or wedges for example between the spokes of one hub part
and the spokes of the other hub part or in any other convenient manner, there
being, if desired a spring to cause one hub part to keep or to tend to keep in
a certain position with regard to the other hub part. I may also employ a
pulley constructed according to my invention constrainedly operated with a
pulley automatically operated or with a pulley of ordinary construction provided
that the slack of the belt be taken up as required in any well known and
convenient manner.
My invention is of special utility for use in connection with motor cars for
varying the speed at which the car shall run in a simple manner and is also
applicable to many purposes where a variation of speed is required either auto-
matically or constrainedly or both automatically and constrainedly.
In the accompanying sheets of drawings I have shown various forms of carrying
out my invention and in which
Fig. 1 is a section of one form of a spring-controlled expanding or contracting
pulley.
Rim 2 io on elevation of the same partly in section.

page_text: Fig. 3 is a detail showing a rim section in perspective.
Figs. 4, 5 and 6 are diagrams showing the driving pulley under different
conditions.
Figs. 7, 8 and 9 are diagrams showing a driven pulley under different conditions.
Figs. 10 and 11 are transverse and longitudinal sections respectively showing
means for adjusting the diameter of the pulley when at rest.
Figs. 12 and 13 are respectively transverse and longitudinal sections showing
means for adjusting the diameter of the pulley when in motion and
Figs. 14 and 15 are detail views of a portion thereof.
Figs. 16, 17 and 18 are detail views showing means for retaining the belt on
the pulley.
Fig. 19 shows a modified construction of pulley for preventing the belt from
running off.
Fig. 20 is a perspective view of a rim section provided with a flexible or
elastic step or steps as a substitute for the usual camber.
Fig. 21 is a perspective view of the rollers for carrying the stepped form of
rim section.
Figs. 22 and 23 show other sections of the stepped form of rims
Fig. 24 shows a modified form of rim section the pulley being contracted
and Fig. 25 shows the same rim sections the pulley being expanded.
Fig. 26 shows a modified form of spoke.
Fig. 27 is a section of the hub of a spring-controlled pulley provided also
with means for controlling the maximum diameter of the pulley when in
motion.
Fig. 28 shows a modified form of controlling bar.
Figs. 29 and 30 are respectively plan and section of a pulley with the rim
in one piece and provided with means for retaining the belt on the pulley.
Fig. 31 shows in sectional elevation a modified arrangement for adjusting the
diameter of the pulley when either in motion or at rest.
Fig. 32 is a diagram showing the same arrangement of slots or feather ways
for adjusting the diameter of the pulley with reference to the arrangement shown
in Fig. 31, and Fig. 33 is a diagram showing a somewhat different arrangement
of slots or featherways.
Referring to Figs 1-3 the hub of the pulley is formed in two parts, that
is to say, an outer hub part a and an inner hub part i one of which according
to the direction in which the pulley revolves is constrained to move with the
shaft a¹ by means of a feather or pin o, the inner hub part being suitably
mounted so as to be capable of being partially revolved relatively to the hub
part a and shaft a¹. The inner hub part i is driven by means of a lug p against
which the pin o bears, said pin working in a slot in the outer hub part a and
bearing against one end of said slot when driving the said outer hub part.
The hub parts a and i are connected together by a torsional spring q one
end of which is attached to the aforesaid lug p on the inner hub part the other
end being attached to a lug r on a wormwheel h mounted freely on the outer
hub part a and controlled by a worm g revolving in bearings in the said outer
hub part whereby the desired torsion on the spring 9 may be attained by means
of a spanner or key.
To suitable lugs or flanges on the aforesaid inner and outer hub parts are
pivotted respectively the two sets of spokes c and 6 the outer ends of each pair
of inner and outer hub spokes being pivotted by a pin d to one of two cheeks f
at one end of each rim section e. Each rim section e is of sufficient length,
when the pulley is expanded to its fullest extent, to overlap the next succeeding
rim section the end being preferably supported on a roller or rollers t carried
by the aforesaid pivot pin d in the next succeeding rim section.
The influence of the tangential pull of the belt on a pulley thus constructed
is clearly shown in the diagrams. Figs. 4-6 a helical spring 9 in tension
being however substituted for the sake of simplicity for the torsional spring q

page_text: own in Figs. 1 and 2. In Fig. 4 a driving pulley driving by the fert, is
its most contracted condition; in Fig. 5 the same pulley is shown at rest
d therefore in its most extended condition while in Fig. 6 the same pulley
shown driving by the right in its most contracted condition.
In the driven pulley the spring q is omitted or replaced by a light spring of
fficient strength only as to tend to expand the pulley.
The action of such a driven pulley is clearly shown in the diagrams Figs. 7, 8
nd 9.
The pulley is shown as being driven by the left in Fig. 7 and in an expanded
ondition; in Fig. the same pulley is shown at rest and therefore in its most
ontracted condition while in Fig. 9 the same pulley is shown in an expanded
condition being driven by the right.
In Figs. 10 and 11 I have shown means for adjusting as desired the diameter
of the pulley when at rest. In bearings in the inner hub part i which is freely
mounted on the outer hub part a keyed to the shaft a is a worm 9 which
One end of the
gears with a worm wheel h fixed to the outer hub part a.
worm g extends beyond the hub and can be caused to revolve by a suitable key
or spanner.
Referring to Figs. 12-15 in which I have shown means for adjusting the
diameter of the pulley when in motion as well as at rest and from a distance,
the outer hub part a is keyed to the shaft a¹ and the inner hub part i is freely
mounted on the said outer hub part. In two diametrically opposite slots in
the sleeve of the outer hub part a I provide sliding racks having diagonally
cut teeth see Fig. 15 both of which gear with corresponding diagonal internal
teeth on the inner hub part i see Fig. 14. The ends of the racks extend beyond
the outer face of the hub part a and attached thereto is a collar m operated
by a fork n. By causing the collar m to slide to or fro the relative positions
of the inner and outer hub parts and therefore the diameter of the pulley may
be adjusted.
In Figs. 16-19 I have shown various means for preventing the belt from
running off the pulley when the rim sections are flat. Referring to Figs. 16
and 17 I may mount freely on each pivot pin d between the cheeks f and the
spokes a washer or disc s or as shown in Fig. 18 I may provide on each side
of each rim section one or more cheeks f¹ or again as shown in Fig. 19 the
flange of the outer hub part a may be increased in diameter so as to extend
beyond the rim of the pulley when in its most expanded position.
The effect of the ordinary camber on the periphery may be attained by making
the rim section step like in section as shown at el in Fig. 20 the elasticity or
flexibility of the rim section being maintained by cutting away the rising
0 portions as shown at with the exception of a short length at the pivotted
end of the rim section. The rollers in such case are stepped to correspond
with the sections of the rim parts as shown in Fig. 21. The ordinary camber
may be more nearly simulated by providing an equal number of steps on either
of the central step e as shown at 22 and e²e, in Figs. 22 and 23 respectively.
In order to allow the pulley to be contracted to less than half its expanded
diameter the end of each rim section may be turned inwards so as to pass the
next succeeding roller t or pivot pin d on the side nearest the centre of the
pulley see Figs. 24 and 25. In such a case instead of sets of straight spokes
and I employ spokes so bent as to be capable of lying as close as may be to
56 the hub part i see Fig. 26.
.5
In Fig. 27 I have shown as an example means for controlling either when in
motion or at rest, the maximum diameter of the automatic pulley described
with reference to Figs. 1-3.
In this construction the worm g and worm wheel h for adjusting the torsion
55 on the spring q is omitted for the sake of simplicity, one end of the said sprin
being shewn as attached to a lug 2 on the inner hub part and the other en
to a lug r' on the outer hub part.

page_text: The outer surface of the sleeve of the outer hub part a is provided with a
helical rib or abutment and the inner hub part is provided with an inner
sleeve cut away, so as to form a helical abutment of equal pitch to that of
the abutment a2 but of reverse direction. A controlling rod or bar passing
through a slot in the outer hub part a carries two rollers one of which bears
against the abutment a² while the other bears against the abutment . This
bar is operated by a sliding collar m and by a fork n. When the bar is
moved in the direction of the arrow the pulley is prevented from expanding
beyond the desired limit but is free to contract against the influence of the spring
by the pull of the belt.
As shewn in Fig. 28 the controlling bar
may be curved or helically bent
in order to reduce the size of the slot in the outer hub.
This arrangement is especially advantageous for controlling the maximum
speed of a motor car in for instance town traffic.
In Figs. 29 and 30 I have shewn a pulley constructed according to my invention
with a rim e formed of a single strip the ends of which overlap. The rim is
held in shape by clips on the pivot pins d which also serve to retain the belt
on the pulley.
In Figs. 31 and 32 I have shewn as an alternative construction for purely
constrained pulleys means whereby the adjustment of the diameter of the pulley
either when in motion or at rest may be effected by the simple movement of
the shaft in the direction of its axis. The two flanges of the outer hub part a
which carry the spokes bare mounted as shewn on the shaft a the simultaneous
motion of the said flanges being assured by pins or feathers o working in slots
or featherways of o¹ of like direction. The inner hub part i which may be
provided with either one flange as shewn in full lines or two flanges or sets of
bosses as shewn in dotted lines for the attachment of the spokes c is connected
to the shaft by a pin or feather 2 working in a slot or featherway o³. The
hub parts and are kept from moving laterally on the shaft a¹ by means of
fixed bearings or collars . By the arrangement of slots o¹, o, o, shewn in
Fig. 32 both hub parts and i are caused to simultaneously and partially
revolve in opposite directions around the shaft a¹ whereas by the arrangement
shewn in Fig. 33 the inner hub part only is caused to revolve partially around
the shaft and as the slots o' of are both parallel to the axis of the shaft the
hub parts.
a cannot revolve independently of the shaft.
It is evident that if it is inconvenient for the shaft itself to slide the slots o¹
and o may be made in a sleeve which slides on a feather in the shaft the hub
parts being mounted on the said sleeve in the same way as they are shewn
mounted on the shaft in Fig. 31.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is: -
1. A pulley provided with a flexible or elastic rim of which the two ends are
adapted to slide into or over each other and a hub made in two parts, each part
being provided with a set of pivotted spokes substantially as described and
shewn.
2. A pulley provided with a rim made up of a number of flexible or elastic
parts adapted to slide into or over each other, a hub made in two parts each part
being provided with a set of tangential pivotted spokes substantially as described
and shewn.
3. A pulley provided with an expanding and contracting rim a hub made
in two parts each part being provided with a set of tangential pivotted spokes
and means for constrainedly adjusting the relative positions of the hub parts
substantially as described and shewn.
4. A pulley provided with an expanding and contracting rim, a hub made
in two parts, each part being provided with a set of tangential pivotted spokes

page_text: the
nd means for constrainedly adjusting the relative positions or
uring the revolution of the pulley substantially as described and shewn.
5. In belt gearing, means for causing the pull of the belt to vary the diameter
of a pulley substantially as set forth.
6. In belt gearing means for causing the pull of the belt to adjust the relative
proportions of the driving and driven pulleys substantially as set forth.
7. In belt gearing where the speed of the driving pulley varies and that of
the driven pulley is to be constant means for causing the pull of the belt to
adjust the relative proportions of the driving and driven pulleys substantially
as set forth.
8. A pulley provided with an expanding and contracting rim, a hub made
in two parts, each part being provided with a set of pivotted spokes and means
for automatically adjusting the relative positions of the hub parts according to
the pull of the belt substantially as described and shewn.
9. A pulley provided with an expanding and contracting rim, a hub made
in two parts, each part being provided with a set of pivotted spokes, means for
automatically adjusting the relative positions of the hub parts according to the
pull of the belt and means for constrainedly adjusting the positions of the
hub parts substantially as described and shewn.
10. A pulley provided with an expanding and contracting rim, a hub made
in two parts, means for driving between said hub parts and the shaft of the
pulley, one hub part being provided with a set of pivotted spokes sloping back-
wards to the direction in which the pulley revolves and the other hub part being
similarly provided with a set of pivotted spokes sloping in the opposite direction
to the first mentioned set of pivotted spokes substantially as set forth.
11. The constructions of pulleys as described and shewn on the drawings.
Dated this Tenth day of September 1900.
JENSEN & SON,
77. Chancery Lane, London, W.C., Patent Agents.