Improvements in Expanding Pulleys for Roving Frames and other Machines.
Year: 1891

page_text: Date of Application, 21st Dec., 1891
Complete Specification Left, 16th Apr., 1892-Accepted, 4 h June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Expanding Pulleys for Roving Frames and
other Machines.
We JOHN CAMPBELL of 40 Kempster Street Lower Broughton Manager and
FREDERICK THOMAS GREENWOOD of 24 Croft Street Joiner both of Manchester
in the County of Lancaster, do hereby declare the nature of this invention to be
as follows:
This invention relates to the construction of expanding pulleys such as are used
in roving frames and other machines for producing a gradually decreasing or a
gradually increasing, or other differential speed.
The invention relates to that class of expanding pulleys which are made of
several sections which approach each other as the pulley is contracted, and recede
from each other as the same is expanded, and the object of the invention is to fill
up the gaps in the periphery caused by the receding of the sections from each
other as the pulley expands so that the working circumference of the pulley shall
always remain solid during both the expansion and contraction of its diameter.
According to our invention we key or otherwise fix on a shaft two wheels at a
convenient distance apart, each having say eight parallel sided arms, and between
these two wheels we mount the expanding pulley in the same number of segments,
cach segment being so arranged that it can move only in a radial direction from
and towards the centre.
Upon the said shaft we mount loosely a cone which is made in sections longi-
tudinally each section being in the form of a long wedge separated by long
parallel slots.
The cone is provided with two ends the bosses of which slide upon the shaft.
The long wedges of the cone pass between the arms of the two wheels, and
through square notches in the sides of the segments of the expanding pulley,
whilst the parallel sided arms of the wheels pass through the long parallel slots
between the wedges before referred to.
When the smallest end of the cone is passing through the expanding pulley the
smaller ends of the wedges hold the segments close together and the pulley is then
at its smallest diameter but as the cone is caused to slide through the pulley the
long wedges gradually force the segments outwards so as to increase the diameter
thereof and this action would under ordinary circumstances cause a gradually
increasing gap to be formed as the junction of cach two segments.
To obviate this however, the cone is provided with wedge like projections, the
diameter of which is equal to that of the driving surface of the pulley and as the
cone advances these wedge like projections enter into and exactly fill up the gaps
which would otherwise be formed, the diameters of these projections on the cone
increasing in the same ratio as that of the pulley, so that the working surface of
the pulley always remains practicably solid notwithstanding that the diameter of
the pulley itself is increased or diminished according to the direction in which the
cone is moved.
201 1
CD
1001
.GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Expanding Pulleys for Roving Frames and
other Machines.
We JOHN CAMPBELL of 40 "Kempster Street Lower Broughton Manager and
FREDERICK THOMAS GREENWOOD of 24 Croft Street Joiner, both-of-Manchester
in the County of Lancaster, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to the construction of expanding pulleys such as are
sometimes used in roving frames and other machines for producing a, gradually
decreasing or a gradually increasing, or other differential speed.
The invention relates particularly to that class of expanding pulleys which are
made of several sections which approach each other as the pulley is contracted,
and recede from each other as the same is expanded, and the object of the invention
is to fill up the gaps in the periphery caused by the receding of the sections from
each other as the pulley expands in diameter, so that the working circumference
of the, pulley shall always remain solid during both the expansion and contraction
of its diameter.
The nature of our said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the sheet of illustrative drawings hereunto annexed and the following explanation
thereof.
Fig. 1 on the drawings is a vertical transverse section of one of our improved
expanding pulleys the pulley being shown as about half expanded, and Fig. 2 is
a longitudinal section of the same.
Fig. 3 is a plan view of one of the long wedges hereinafter referred to.
Fig. 4 is a transverse section taken through about the line A-B in Fig. 2 the
pulley being almost fully expanded and
Figs 5 and 6 are views of the respective ends of the cone.
According to our invention we key or otherwise fix on a shaft a two wheels b
and c at a convenient distance apart, each having (say) eight parallel-sided arms,
and between these two wheels we mount the expanding pulley. having the same
number of radially divided segments d grooved on its outer face and each segment
being so arranged that it can move only in a radial direction from and towards the
centre-sliding up and down its respective arm.
Upon the said shaft a we mount loosely a skeleton cone which is made in sections
dongitudinally, each section being in the form of a long wedge (see Fig. 3) and
they are separated by long parallel slots.
The cone is provided with two ends the bosses of which slide upon the
shaft a. The long wedges of the cone pass between the arms of the two wheels b
and e'and their edges pass through square notches in the sides of the segments d
of the expanding pulley (see Fig. 4) and support them whilst the parallel-sided
arms of the wheels pass through the long parallel slots between the wedges
the cone before referred to, there being thus one end of the cone on each side of
the expanding pulley.
.g
of
When the smallest end of the cone is passing through the expanding pulley the
smaller ends of the wedges hold the segments close together and the pulley is
then at its smallest diameter (see Fig. 5) but as the cone is caused to slide through
the pulley (see dotted lines on Fig. 2) the long wedges gradually force the
segments d outwards so as to increase the diameter. thereof, and this action would
under ordinary circumstances cause a gradually increasing gap to be formed at the
junction of each two segments.
To obviate this however the wedges of the cone are provided with wedge-
like projections curved on the face to agree with the form of the segments d,

page_text: and as the cone advances these wedge-like curved projections enter into and exactly
fill up the gaps which would otherwise be formed the diameter and width of these
projections on the cone increasing in the same ratio as that of the pulley, so
that the working surface of the pulley always remains practically solid and circular
notwithstanding that the diameter of the pulley itself is increased or diminished
according to the direction in which the cone is moved.
It will be evident that if the outer faces of the segments d form a complete
circle when the pulley is contracted to its smallest diameter (see Fig. 5) the same
faces cannot form absolutely accurate segments of a circle of larger diameter
formed by the pulley when fully expanded.
To reduce this error to a minimum we turn the surface of the segments & to
coincide with the faces of the cones when the pulley is half-way expanded
(see Fig. 2) so as to obtain the mean curve between the maximum and minimum
and thus the error becomes so slight that the pulley is for all practical purposes
circular at any state of expansion or contraction.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The improved construction of expanding pulleys for roving frames and other
machines by the combination with radially moving segments of a sliding cone
formed of long wedges with curved faced projections, which as the radial segments
of the pulley are expanded fill up the gaps between the segments which would
otherwise be formed so that the working surface of the pulley is always solid and
circular in whatever state of expansion or contraction it may be, substantially as
hereinbefore described and illustrated by the drawing annexed.
Dated this 14th day of April 1892.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.