IMPROVEMENTS IN APPARATUS FOR RAISING AND LOWERING WEIGHTS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by William Eades and William
Thomas Eades at the Office of the Commissioners of Patents, with
their Petition, on the 7th November 1871.
We, WILLIAM EADES and WILLIAM THOMAS EADES, both of Birming-
ham, in the County of Warwick, Machinists, do hereby declare the nature.
of the said Invention for "IMPROVEMENTS IN APPARATUS FOR RAISING AND
LOWERING WEIGHTS," to be as follows, that is to say:
Our Invention refers to the construction of pulley blocks or hoists in
such manner that they may be worked with ease, readiness, and certainty
of action, and the improvements more especially have for their object
the due regulation and adjustment of the parts at will when lowering
for the prevention of any sudden descent of the load.
We form a framework having a hook or other suitable means for the
suspension of the block or hoist; in the framework are arranged the
working parts consisting of a spindle held in bearings in the side arms
of the framework. Upon the spindle are mounted two pulley wheels of
unequal diameters; the larger pulley is employed for actuating the
smaller or lifting pulley, and both pullics are suitably formed with
0

page_text: projections or sinkings-in grooves upon their peripheries to receive the
chain links; the larger pulley has an endless chain for the pull or lever-
age required, the lifting pulley being provided with a suitable chain or
chains having hooks for attachment to the load to be raised or lowered.
The parts thus far described are not new having been previously used
in pulley blocks, and we will now proceed to describe the improved
additional parts which in combination with those already specified
comprise our Invention.
That portion of the spindle upon which the larger or leverage pulley
revolves is wormed as a screw, the pulley being tapped through the
centre to work upon it; between the actuating pulley and the lifting
pulley is arranged an adjustable conc, disc, or plate of a wedge form or
having a tapered side edge in section and mounted upon a square part
of the spindle so as to revolve with it; this cone, disc, or plate is also
capable of a slight to-and-fro sliding action upon the square part of the
spindle so as to impinge upon or work into the side face of the smaller
pulley as herein-after described, and upon the other side of the smaller
or lifting pulley is similarly arranged a second cone or disc collared upon
or formed with the spindle, a ratchet pinion and pawl being suitably
secured at the back of the second cone.
In working a pulley block or hoist so constructed the endless chain
is pulled one way, actuating the leverage pulley, which working upon
its screwed axis bears or impinges into or upon the face of the middle
or adjustable conc, disc, or plate, thereby wedging between it and the
second or outer cone the lifting pulley, which being thus tightly held
travels with the larger or leverage pulley, so as to raise the load, which
at any distance may be stopped by releasing the endless chain, the
operation of the pawl and ratchet wheel acting as a stop.
In lowering a weight or load, the endless chain must be slightly pulled
the reverse way, which will cause the leverage pulley to work in the
same direction, moving back upon its screw sufficiently to release the
intermediate adjustable conc, disc, or plate from its grip upon the lifting
pulley, the cone slightly sliding upon its square axis, thus allowing the
lifting pulley to revolve for the descent of the load.
It will be obvious that by the arrangement of an adjustable cone, disc,
or plate as described the lowering of the load may be regulated or
controlled at will according to the amount of friction brought to bear

page_text: upon the raising or lowering pulley by means of the cones, and without
any danger of the load suddenly slipping or decending too rapidly,
whilst at any distance the lowering operation may be stopped by the
gripping or tightening action of such cones being applied.