Improvements in or relating to Variable Sized Pulleys or Wheels.
Year: 1896

page_text: Date of Application, 29th Dec., 1896-Accepted, 13th Feb., 1897
Improvements in or relating to Variable Sized Pulleys or Wheels.
A communication from HEINRIOH BLUM, Engineer and Manufacturer, of Neuenstadt,
Canton Bern, in the Republic of Switzerland.
I, ALFRED JULIUS BOULT of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, 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 :-
The present invention relates to a pulley or wheel the arms of which aro constructed
so that they may be extended in a radial direction and secured in desired position, the
rim being interchangeably mounted on the arms so that by exchanging one rim for
another of different diameter or width and by correspondingly adjusting the arms, the
diameter of tho wheel may be varied within certain limits.
In the accompanying drawings a pulley is illustrated in Figures 1 to 6.
Like letters indicate like parts throughout the drawings.
Each arm of this pulley consists of two parts a and b. The part a is secured at
one end to the hub c of the pulley, the other end of said arm being provided with a
clamping or holding device by means of which the part b which is adjustable in the
part a, may be secured or clamped in different positions.
On the inner surface of the rim d are arranged pins e which are adapted to engage
with corresponding holes e', (Figs. 5 and 6) provided in plates arranged on the arm-
parts b. Thus the movement of, the rim relatively to the arms is prevented. The
rim is preferably made from a suitably bent plate, the ends being hinged or
otherwise secured together. The rim may be easily removed by withdrawing the
hinge-pin g and by releasing the nearest arm-part 6 and then by pulling the ends
of the rim away from each other. If it is desired, say to increase the diameter
or the width of a pulley, its rim is removed, the arm-parts 6 are sufficiently with-
drawn from the arm-parts a to produce the diameter required and then fixed in
this position. The new rim with its ends held apart is placed on and around the
arms, whereupon said ends are connected by inserting in the hinge-pin or otherwise
Becuring the ends.
To facilitate the adjustment of the arm-parts b to the desired diameter, it is
preferable either to provide the arm-parts b with a scale (Fig. 5), the divisions of
which correspond to certain alterations in the diameter of the pulley or with a screw-
thread and nut 6 (Fig. 6), whereby the adjustment may be easily regulated. For
securing the parts a and b together when adjusted, in tho drawing the tabular part a
is shown with a longitudinal slit and having projecting lugs adapted to be drawn
together by bolts, but any other suitable means may be employed.
Having now particularly described and ascertained the nature of the said
invention as communicated to me by my foreign correspondent I declare that what
I claim is ;-
1. A pulley or wheel the diameter or width of rim of which may be varied con-
stituted by a central hub carrying arms which can be expanded and adjusted to
receive and secure interchangeable.rima substantially as described.