Improved Expansible Pulley
Year: 1897

page_text: Improved Expansible Pulley.
SAMUEL WALKER, Engineer and Ironfounder, Eagle Iron Works, Radcliffe,
Lancaster, and JOHN POOLE, Engineering Works Manager, Eagle Iron Works,
Radcliffe, Lancaster, do hereby declare the nature of this invention to be as
follows:
This invention relates to improvements in the construction of expansible pulleys,
that are used on machines or shafting which require to have means provided to
permit of speed being altered or varied.
The said improvement consists in employing a boss carrying two or more arms;
the boss being secured to shaft in the ordinary way.
Each arm is fitted with a segment of the rim, the segments being arranged to
slide on the arms; either to or from the boss as required.
The segments are each a portion of the pulley rim, with a hollow boss cast inside,
arranged to slide upon the fixed arms. Each segment-boss is connected by means
of links to a sleeve on the shaft. The sleeve may be moved along the shaft, and
in so doing varies the diameter of pulley.
SAML. WALKER.
JOHN POOLE.
We, SAMUEL WALKER, Engineer and Ironfounder, and Joux POOLE, Engineer-
ing Works Manager, both of Eagle Iron Works, Radcliffe, 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 ascertained in and by
the following statement:-
This invention relates to pulleys the peripheries of which are capable of being
expanded or increased and reduced in diameter by moving the periphery in

page_text: segments from or towards the centre and it is designed to provide efficient mechan-
ism for holding the several segments in position and moving them to or from the
centre as may be required to permit of the speed of the machine to which the
power is transmitted being varied or adjusted.
It consists essentially in constructing the pulley with the rim or periphery
formed of two or more segments a boss or hub with a corresponding number of
arms to which the segments of the rim are fitted and upon which they are
capable of sliding a sleeve to slide to and fro on the shaft and links connecting the
sleeve with the segment by which the movement of the segments is effected.
The invention will be fully described with reference to the accompanying
drawings
Fig. 1. Sectional elevation.
Fig. 2. Transverse sectional elevation.
The rim or periphery of the pulley is formed of a number of (preferably four)
removable adjustable segments or segmental pieces Beach provided with a socket b
on the inner side.
The boss A of the pulley is provided with a number of arms or spokes a pre-
ferably four, corresponding in number with the number of the segments B. The
arms a are of circular or other cross section and fit into the sockets of the
segments B or in other words the sockets b fit over the arms a and may slide to
and fro thereon. When the pulley arms are of circular section a setscrew a¹
passing through a slot in the sleeve B is employed to prevent the segment from
twisting on the arm, and it may also be employed for locking the segment in
position when adjusted. Instead of a setscrew and slot, a feather key, or flat
and set screw, or other simple device may be employed to prevent the socket b
turning thereon.
Connected to the segments B of the pulley by links C is a sleeve D which is
placed loosely on the shaft E to which the pulley is fixed so as to be free to slide
thereon. It is moved to and fro by a forked lever actuated by a screw hand lever
or otherwise. It is to be understood that instead of sockets on the inner side of
the segments, arms may be substituted therefor and sockets substituted for the
arms attached to the boss.
When in use or in operation the boss A of the pulley is keyed or otherwise
affixed to the shaft E so as to rotate therewith and the segments B are fitted upon
the arms a radiating from the boss A. Each segment B is by one or more links C
connected with the sliding sleeve D. By moving the sleeve D along the shaft E
the angle of the links to the shaft E is altered and the segments moved away
from or towards the centre according to the direction of the movement of the
sleeve 1). If movement is in a direction away from the pulley the segments are
drawn nearer to the boss and the diameter reduced, if towards the pulley the links
approach the vertical and the segments are forced away from the boss and the
diameter increased.
The same construction of pulley fitted inside a suitable casing forms a friction
clutch.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
-
1. An expanding pulley constructed with the rim in two or more sections each
section fitting on to a corresponding radial arm attached to the boss upon which
it is free to slide to and fro, substantially as described.
2. In an expanding pulley the combination with a boss to be fixed to the shaft
provided with radiating arms (or sockets) of a rim formed of two or more sections
each provided with a socket (or arm) to engage with the radiating arms of the
boss, a sleeve capable of sliding on the shaft and links attached to the segments
and to the sliding sleeve whereby the movement of the sleeve is transmitted to
the pulley to increase or reduce its diameter substantially as described.

page_text: 3. An expanding pulley having the several parts constructed and arranged in
combination substantially as described and shown.
Dated this 17th day of February 1898.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.