Year: 1885

page_text: I, EDWARD PITCAIRN WRIGHT, of Woodville, Handsworth, in the County of
Stafford, do hereby declare the nature of my said invention to be as follows:-
The object of my invention is to manufacture pulley blocks in an improved
manner, such pulley blocks being more simple and compact than those in ordinary
use.
In carrying out my invention, I use a deeply grooved pulley, the groove of
which is pitched to fit the links of the chain. The outer portions of the groove,
(extending to both edges of the groove), are cut or otherwise formed with worm
teeth. Above the sheave or pulley,. a short horizontal axle is fitted, having a
worm which gears into the worm teeth of the pulley.-One end of this axle is
fitted with a sprocket wheel for the hand chain, whereby the screw is operated.
The screw and pulley are both mounted in one frame, with the usual hook at
the top. Provision is made for anchoring one end of the pitch chain to the frame.
A small sheave is also fitted to guide the free end of the pitch chain to a central
position below the wheel.
The pitch chain descends from the anchorage: passes round the lower half of the
ordinary bottom block: then up to and round the upper half of the worm wheel
or pulley: then past the small sheave to a central position.
The free end of the chain is fitted with a hook, to which light articles may be
attached, and hoisted at double the speed of the bottom block.
From the foregoing description it will be understood that, instead of arranging
for the lifting chain to be carried by a separate cast iron or malleable pulley, fixed
at the side of the worm wheel, as hitherto arranged, I combine the action of the
two in one wheel, and thereby bring the centres of the worm and worm wheel, and
the strains upon the same, into one common vertical line.

page_text: I, EDWARD PITCAIRN WRIGHT, of Woodville, Handsworth, in the County of
Stafford, do hereby.declare the nature of my said invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The object of my invention is to manufacture pulley blocks in an improved
manner, such pulley blocks being more simple and compact than those in ordinary
use.
In carrying out my invention, I use a deeply grooved pulley, the groove of
which is pitched to fit the links of the chain. The outer portions of the groove,
(extending to both edges of the groove), are cut or otherwise formed with worm
teeth. Above the sheave or pulley, a short horizontal axle is fitted, having a
worm which gears into the worm teeth of the pulley. One end of this axle is
fitted with a spocket, wheel for the hand chain, whereby the screw is operated.
The screw and pulley are both mounted in one frame, with the usual hook at
the top. Provision is made for anchoring one end of the pitch chain to the frame.
A small sheave is also fitted to guide the free end of the pitch chain to a central
position below the wheel.
The pitch chain descends from the anchorage: passes round the lower half of
the ordinary bottom block: then up to and round the upper half of the worm
wheel or pulley: then past the small sheave to a central position.
The free end of the chain is fitted with a hook, to which light articles may be
attached; and hoisted at double the speed of the bottom block.
From the foregoing description it: will be understood that, instead of arranging
for the lifting chain to be carried by a separate cast iron or malleable pulley, fixed
at the side of the worm wheel, as hitherto arranged, I combine the action of the
two in one wheel, and thereby bring all the various strains upon the block into
one common vertical plane.
And in order that my said invention may be particularly described and
ascertained, reference is hereby made to the accompanying drawings, in which
similar letters of reference indicate corresponding parts.
Fig. 1 is an elevation shewing the block edgewise.
Fig. 2 is a side view of the same.
a is the worm, carried by the axle b, and actuated by the spocket or hand-
wheel c and hand-chain d. The worm a gears into the worm-wheel e, as sbewn.
The worm-wheel e has a groove e¹ to receive the power chain f, and in this groove
pitch teeth e² are formed or fitted to carry the pitch chain f.
Each side of this groove is provided with portions of screw threads a², into
which the worm a gears, and by which the worm-wheel is actuated.
The chain is anchored at g, it then descends to and passes under the bottom
block h, and from thence it passes up to the power pulley or worm wheel e; the
7.

page_text: chain is then carried downwards, between the two guide wheels ii, below which
an additional hook k is fitted, for raising light goods quickly. is the hook for
attaching the block to a staple or other convenient support, and m is the hook for
heavy goods.
In some cases where a more simple form of apparatus is required the bottom
block and the pulley sheaves i i may be dispensed with, and a lifting hook fitted
at each end of the chain f.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The manufacture and use of pulley blocks or apparatus for raising heavy
weights, having the main lifting chain of the block in the same vertical plane as
the worm and worm wheel, substantially as and for the purposes herein before
described and shewn on the drawings.
. 2. The general construction combination and arrangement of the several and
respective parts, together forming my improvements in pulley blocks or apparatus
for raising heavy weights, substantially as herein before described and shewn on
the drawings.