An Improved Adjustable or Expanding Pulley.
Year: 1888

page_text: Date of Application, 29th Sept., 1888
Complete Specification Left, 24th June, 1889-Accepted, 3rd Aug.. 1889
PROVISIONAL SPECIFICATION.
An Improved Adjustable or Expanding Pulley.
I THOMAS OWEN ARNFIELD of Globe Iron Works New Mills in the County of
Derby Engineer do hereby declare the nature of this invention to be as follows:-
--
The object of this invention is to construct an improved arrangement of an
adjustable or expanding pulley for driving paper making machines calenders or other
machines or gear where the speed requires to be varied whilst the driving pulley is in
motion.
The improved pulley consists of a boss which is keyed on the shaft and is provided
with three or more straight radial arms of a circular or other convenient section.
The rim of the pulley is divided into three or more parts or segments corresponding
with the number of arms.
The interior of each segment of the rim is provided with a radial socket which
is bored out or otherwise formed to fit onto the arms and is connected by a diagonal
link to a clutch or sleeve sliding upon the shaft.
It will be evident that by sliding the clutch or sleeve along the shaft the segments
of the pulley will be simultaneously moved outwards or inwards and thus the
circumference of the pulley will be expanded or contracted, and this may be readily
done either where the pulley is at rest or in motion.
Dated this 28th day of September 1888.
GEORGE DAVIES,
4, St. Ann's Square, Manchester, Agent for the Applicant.
COMPLETE SPECIFICATION.
An Improved Adjustable or Expanding Pulley.
I, THOMAS OWEN ARNFIELD of Globe Iron Works New Mills in the County of
Derby 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 :—
In machinery for finishing woven fabrics and in paper making machinery or other
arrangements of machinery where two or more ranges of drying cylinders are used
or in any other arrangement of machines which are required to be driven simultaneously
it frequently happens that the different portions of the range are required to be driven
at different speeds.
Hitherto cone pulleys, or expanding pulleys of a very complex construction have
been used for this purpose.
There are several objections to the use of cone pulleys, as in addition to the extra
space taken up thereby the belt requires to be kept in position by means of a guide
or fork, and as this guide or fork is necessarily continually pressing against the belt, the
edge thereof very soon becomes worn away especially where woven belts are used.
The expanding pulleys hitherto in use are of so complex a construction as to be very
expensive both in first cost and for repairs.
The object of this invention is to construct a simple and improved arrangement of
an adjustable or expanding pulley for driving such machines, especially where the
speed required to be varied whilst the driving pulley is in motion.
The nature of my said invention and the manner in which the same is to be per-
formed or carried into practical effect will be readily understood on reference to the
accompanying drawings and the following explanation thereof.
Fig. 1, on the drawings is a side elevation (drawn partly in section) of one of my
improved adjustable or expanding pulleys, and Fig. 2 is a vertical section of the same,

page_text: the upper half thereof showing the pulley as fully expanded and the lower half showing
the same closed or reduced to its smallest diameter.
The improved pulley consists of a central boss a which is keyed onto the shaft and
is provided with a number of straight radial arms 6 of a circular section.
The rim of the pulley is divided into a number of parts or segments c corresponding
to the number of arms and the outer edge of each segment forms a portion of a
circle the radius of which is suitable to the diameter of the pulley required.
The interior of each segment c, of the rim is provided with a radial socket & cast
in one piece therewith and bored out to fit onto the arms, or if preferred the
sockets d may be cast onto the central boss a and the arms b onto the interior of
the segments c.
Mounted on the same shaft is a sliding sleeve or boss e which is coupled by means
of suitable links f to all of the segments c.
It will be evident that by sliding the boss sleeve e along the shaft in one direction
or the other the segments c will be caused to simultaneously recede from or approach
nearer to the centre of the shaft, thus increasing or reducing the diameter of the
pulley as shown at the upper and lower halves of Fig. 2.
By using these expanding pulleys in pairs and so arranging the levers acting on
the sliding bosses or sleeves that when the diameter of one pulley is increased the
diameter of the other is reduced (and vice versa) a very simple and efficient arrange-
ment is obtained by means of which the speed may be varied to any required extent
whilst the machine is in motion, or when the pulley is at rest as may be preferred.
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
First. An improved adjustable or expanding pulley for varying the speed of the
machinery whilst in motion or at rest, constructed and arranged substantially as
herein before described and illustrated by the drawings annexed, and
Secondly. The use of radial arms circular in section combined with radial sockets
bored out to fit the same to act as the sliding surfaces in adjustable or expanding
pulleys for such purposes.
Dated this 21st day of June 1889
GEORGE DAVIES,
4, St. Ann's Square, Manchester, Agent for the Applicant.