IMPROVEMENTS IN APPARATUS FOR RAISING AND LOWERING HEAVY BODIES."
Year: 1866

page_text: LETTERS PATENT to Robert Anthony Hardcastle, of the Town and County
of Newcastle-on-Tyne, for the Invention of "IMPROVEMENTS IN APPARATUS
FOR RAISING AND LOWERING HEAVY BODIES."
PROVISIONAL SPECIFICATION left by the said Robert Anthony Hard-
castle at the Office of the Commissioners of Patents, with his Petition,
on the 22nd March 1866.
I, ROBERT ANTHONY HARDCASTLE, of the Town and County of Newcastle-
on-Tyne, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN APPARATUS FOR RAISING AND LOWERING HEAVY BODIES," to be as
follows:-
This Invention relates to certain improvements upon and modifications of
the pulleys known as " Weston's differential pulley blocks," for which Letters
Patent were granted to Thomas Aldridge Weston, bearing date the 25th of
April 1859, No. 1033, and has for its object the affording facility for adjusting
the distance of the blocks at any time, and for lowering weights with greater
rapidity than can be effected under the existing forms of such pulley blocks,
the same apparatus possessing all the advantages of the "differential pulley
block" when used as such.
According to this Invention it is proposed to make the two sheaves of the

page_text: block separate from each other in lieu of casting or forming them in one
piece, and arranging them so that they may be engaged or disengaged from
each other at the will of the operator. This can be effected either by an
ordinary sliding clutch or by sliding one of the sheaves and providing it with
pins or other projections fitting into corresponding holes in the other sheave,
or by any other well-known mechanical contrivance. The sheaves can be
connected or disconnected by moving the clutch or sliding sheavebymeansof
a lever, cord, wedge, spring, or other suitable means. If when the sheaves are
disconnected oneof them be locked soas to prevent it turning roundit will hold
fast that portion of the chain running over it and enable the attendant by hold
ing on the opposite portion of the chain running over the loose shcave to lower
or raise suitable weights. This locking can be effected by separate means or
by an extension of the same contrivances which throw the sheaves in and out
of gear with each other. When the sheaves are in gear the well-known
differential action is obtained, but should it be desired to lower a weight more
rapidly than the difference in the circumference of the two sheaves will admit
of when used as differential pulleys the attendant has simply to disengage the
sheaves, as before described, and they then operate independently. By making
fast or securing one part of the slack loop of the endless chain, or locking
one of the sheaves, the sheaves being disengaged from each other, as above
described, the manipulator will still have a purchase of two toone plus friction
over the weight and may lower it with rapidity. By using these pulley
blocks with their sheaves uncoupled as described they may be inade available
for raising light weights, the power being two to one, and by coupling the
sheaves again the increased power due to the differential action of the pulleys
is obtained; a catch or other well-known contrivance is adapted to the frame
of the block for the purpose of retaining the sheaves uncoupled or disconnected
so long as they may be required to operate in that condition.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Anthony Hardcastle in the Great Seal Patent
Office on the 20th September 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
ANTHONY HARDCASTLE, of the Town and County of Newcastle-on-Tyne,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Twenty-second day of March, in the year of our

page_text: Lord, One thousand eight hundred and sixty-six, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Robert Anthony Hardcastle, Her special licence that I, the
said Robert Anthony Hardcastle, my executors, administrators, and assigns,
or such others as I, the said Robert Anthony Hardcastle, my executors,
administrators, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend, within
the United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for. "IMPROVEMENTS IN APPARATUS FOR RAISING AND
LOWERING HEAVY BODIES," upon the condition (amongst others) that I, the
said Robert Anthony Hardcastle, my executors or administrators, by an
instrument in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of
the said Letters Patent.
NOW KNOW YE, that I, the said Robert Anthony Hardcastle, 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, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to say :-
My said Invention relates to certain improvements upon and modifications
of the pulleys known as "Weston's differential pulley blocks," for which
Letters Patent were granted to Thomas Aldridge Weston, bearing date the
25th of April 1859, No. 1033, and has for its object the affording of greater
facility for coupling and uncoupling the sheaves, whereby the distance
between the fixed block and the snatch block can be adjusted at any time,
so as to vary the range of lift at will, and weights may be moved with
greater rapidity than can be effected by the differential pulley blocks abovo
alluded to, the same apparatus possessing all the advantages of the
"differential pulley block," when used as such.
According to my present Invention I propose to make the two sheaves or
the “differential pulley block" separate from each other, and to couple or
uncouple them by means of a sliding clutch, or by using a sliding sheave, and
to provide one or both the sheaves with pins, cogs, or other projections, which
engage with or into corresponding projections, holes, or depressions formed
on or made in the contiguous face of the adjoining sheave, or the two sheaves
may be coupled together by forcing the one against the other laterally by

page_text: means of a wedge, inclined plaue, or spiral thread or threads acting upon
the sliding sheave.
By the means above referred to greater facility is afforded for coupling
or uncoupling the sheaves, whereby the same pulley block is rendered
capable of being used either as a "differential pulley block" by coupling
the two sheaves together, or as an ordinary block by uncoupling or dis-
engaging the sheaves from each other, in which case if one of the sheaves
be looked so as to prevent it from turning round it will hold fast that
portion of the chain running over it and enable the attendant by holding
on the opposite portion of the chain running over the loose sheave to raise
or lower weights in the same manner as with an ordinary block. This
locking of one of the sheaves can either be separately effected or it may be
effected by an extension of the same contrivances which serve to uncouple
the sheaves.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the Figures.
Figure 1 of my Drawings represents a front elevation of a differential pulley
block wherein the coupling and uncoupling of the sheaves is effected by a
sliding clutch, and Figure 2 is a corresponding side elevation of the same, look.
ing in the direction of the arrow in Figure 1. a and b represent respectively
the larger and smaller sheaves of the block, which in all cases should have
their peripheries so formed as to prevent the surging or slipping of the endless
chain x, y, over them; the sheave a runs loose on the spindle c, and the
sheaveb is keyed or otherwise made fast thereon, an enlargementor shoulderd
being formed on the spindle in order to keep the sheaves in their places; e is a
clutch box, sliding along the part of the spindle, and prevented from turning
thereon by the key g. This clutch is provided with one or more pins or other
projections,f, which enter corresponding holes or depressions in the face of
the sheave a, when the coupling is effected; is a lever carried by the frame of
the block for throwing the sliding clutch e in or out of gear with the sheavea,
and i is a spring which may be used if found desirable for maintaining the
clutch in gear. The cord k attached to the lever h, and passing over a guide
pulley in the frame descends to within easy reach of the hand of the operator,
who ou pulling the cord can at any moment throw the clutch out of gear with
the sheave a, whereupon the sheave a will be left free to revolve on the
spindle c independently of the sheave b. By locking the sheave b, by means
of the pallcarried by the frame and engaging into the ratchet wheel m fast

page_text: on the spindle, or into teeth formed on the sheave itself, the portion y of the
chain will be held fast, whilst the other portion a passing over the loose
sheave a may be haulet upon or let go, as the case, may be for the purpose of
raising or lowering light weights with rapidity. On releasing the cord the
spring i will throw the clutch e in gear with the sheave a, when as the two
sheaves will then rotate together with the spindle c the arrangement may be
used in the same manner as "a differential pulley block" As the pall / will
only allow the sheaves to revolve in the direction for lowering a weight by the
differential action it will be necessary to throw it out of gear with the ratchet
wheel m, should it be required to hoist differentially. If the pulleys be
reversed, and locked, it will be seen that the pall will have to be thrown
out of gear to lower differentially. In the arrangement last described it
will be seen that neither of the sheaves slide laterally, and that the coupling
and uncoupling is effected solely by a sliding clutch box.
In the modification illustrated by Figures 3 and 4 the sheave a is caused
to slide to and from the sheave b along the spindle c by the same means as
those described for sliding the clutch in the first arrangement, the lever h
being caused to engage in a groove in the boss of the sliding sheave a.
Both the sheaves a and b may be loose on the spindle c, or one of them may
be fast or caused to revolve therewith, whilst the other is loose thercou."
The coupling of the two sheaves is in this modification effected by the pin
or projection fin one sheave entering a corresponding hole in the other
sheave when the two are brought together.
Fig. 3 represents the two sheaves coupled together and operating as a
"differential pulley block;" and Figure 4 shows them uncoupled or dis-
engaged from each other. The locking of the sheave a is effected by the
mere act of uncoupling a stud or pin z in the frame, being caused to onter
an aperture in the sliding sheave as it is being withdrawn from the other
one, and so locks it and holds fast the part of the endless chain, whilst
the part y is free to be hauled or let go over the pulley 6 for raising or
lowering a weight with rapidity.
Figures and 6 illustrate a third modification wherein the sheaves a and b
are coupled or geared together by the mutual interlocking of a series of
inclined or wedged-shaped projections or ratchet teeth s and p formed on the
contiguous faces of the two sheaves respectively, the locking of one of the
sheaves being also effected by inclined projections 2 on the outer face of the
sheave engaging with a corresponding inclined projection formed on or fitted
to a convenient part of the frame of the block. In this modification, as in the
one last described, the same movement which serves to uncouple the sheaves

page_text: locks one of them, but the coupling and uncoupling of the two sheaves and
the locking and releasing of one of them is effected by the ordinary endless
chain attached to the block, the separate cord k, lever h, and spring i being
dispensed with. Figure 5 shews the sheaves a, b, uncoupled and the sheave a
locked; and Figure 6 shews the same sheaves coupled orengaged together and
acting as differential pulleys. The inclined projectionss and'p which are formed
on the inner faces of the sheaves a and b respectively are made to lock into
each other in such a way that the weight suspended from the snatch block w
tends to keep them so locked or coupled together as shewn in Figure 6. The
sheaves a and b being thus coupled by hauling on the part of the chain the
weight will be lifted, and by hauling on the party of the chain the weight will
be lowered differentially, but by hauling in both parts x and y of the endless
chain simultaneously with sufficient force to overcome the gravity of the
weight, the inclined projections s and p would slide or pass over each other
and thereby force or wedge the sheave a partly into the fixed stop z with
which one of the series of inclined projections becomes engaged, whereupon
the said sheave will be locked or prevented from turning in one direction,
and will consequently hold fast the part of the chain where it passes
over the said sheave. By continuing to haul on the part y of the chain
the sheave a will be completely engaged or locked with the stop z and wholly
uncoupled or disengaged from the sheave b. In this condition of the pulley
the weight ean be readily raised or lowered with a power of two to one by the
portion of the chain and the sheave b. In lieu of hauling on both parts a
and y of the chain simultaneously for the purpose of uncoupling the sheaves,
this may be accomplished by making fast one part of the chain and hauling on
the other. It will be seen on referring to the Drawing that the sheave a
cannot be uncoupled from the sheaveb without being at the same time locked
or engaged with the fixed stop z, also that it is impossible for the operator to
uncouple the sheaves when acting differentially unless he has power of lifting
the weight, hence no risk is incurred of the operator being overpowered
on uncoupling the sheaves when acting differentially, as more power will be
required to effect such uncoupling than to sustain the weight when the
sheaves are uncoupled. The two sheaves when separated or uncoupled can
again be brought together and coupled by hauling on the parts x and y of
the chain.
y
Figures 7 and 8 illustrate another modification wherein the sheaves a
and 6 are coupled and uncoupled by moving one of them laterally by hand
along the spindle c, each sheave being provided with one or more projections
s, p, the projections s on one sheave locking against the projection p on the

page_text: other sheave.
uncoupled.
The projection q and serve to lock the sheave a when
Figures 9 and 10 illustrate another modification for coupling and uncoupling
the sheaves a and b; Figure 9 showing the sheaves uncoupled,and Figure 10
coupled. In this arrangement an inclined plane in the form of a spiral
thread or threads is employed as the medium for coupling and uncoupling the
sheaves, the requisite motion of the parts for effecting such operations being,
as in the arrangement shown at Figures 5 and 6, derived solely from the
ordinary endless chain passing over the sheaves of the block. The spindle c is
provided with spiral threads or projections p, which engage into corresponding
spiral grooves made inside the centre of the sheave a, whilst the sheave 6
is fast on the spindle c. On hauling both parts & and y of the slack portions
of the chain simultaneously the sheaves will be separated by the action of the
spiral thread (see Figure 9) until the sheave a is moved entirely sufficiently
far to be locked by the inclined projections 9 and z, as in Figures 5 and 6,
and to be released from the spiral threads or projections p. In this condition
the sheave with its spindle is free to rotate independently of the sheave a,
and the block:
I may then be employed for expeditiously raising or lowering light
weights with a purchase of two to one. The sheaves when separated may
again be coupled by hauling on the parts x and y of the chain, when the
inclined projections q and z will by sliding over each other force the sheave a
in contact with the spiral threads p; by now releasing the part y of the chain
the weight at w will rotate the spindle c, and cause the spiral threid to enter
the sheave a, and so tighten the two together, as in Figure 10, when the
differential action will be resumed.
Figure 11 represents a sectional elevation of another modification wherein
the results herein-before referred to are obtained by the use of a sliding clutch
in lieu of a sliding or laterally adjustable sheave,such clutch being thrown in
and out of gear with one of the two sheaves so as to couple and uncouple
the same, and simultaneously locking the larger pulley a, and releasing it
again by the sole action of the ordinary endless chain in the inanner herein.
before described in reference to Figures 5 and 6 of my Drawings. a is the
larger sheave; b, the smaller one; and c the spindle or axis of the same.
Upon this spindle c revolves freely the sliding clutch e, a detail elevation of
which is shown at Figure 13. This clutch is made square or of such other
form at the part g where it enters the shea ve a as will prevent the said sheave
from turning; on the clutch s are inclined projections or ratchet teeth formed
on one end of the clutch, which engage with corresponding ratchet teeth on
the inner face of the smaller sueave b. On the opposite end of the clutch e

page_text: there are formed a series of inclined projections or ratchet teeth 9, which
when the clutch is disengaged from the sheave & become locked or engaged
with a correspondingly shaped or inclined catch or stop z formed on the
interior of the frame of the block. The direction of inclination of the several
teeth or projections s, p, q, and z, is the same as illustrated by Figures 5
and G, and hence the coupling and uncoupling of the sheaves, and the
locking of one of them may be effected by the chain itself in the manner
already described, the only difference being that in lieu of the sheave a
moving laterally under the operation of the inclined projections, it is the
clutch which receivos that motion, and slides freely inside the sheave a
It will be readily seen that although in Figures 3 to 12 the large sheave
slides and locks, the same operations can be performed if the small sheave is
made to slide and lock.
Having now described and particularly ascertained the nature of my said
Invention, and the manuer in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I am aware that it has
already been proposed to employ separate or divided sheaves capable of
independent action in what are known as "Weston's differential pulley
blocks," with a view to lowering weights, and also that it has been proposed
where three or more sheaves are employed in a differential pulley block to
make one of them capable of being disconnected from the rest with a view
solely to enable more or less chain to be taken in or let out from such loop
in order to vary the range of lift, and therefore I do not claim as of my
Invention the use in differential pulley blocks of a sheave capable of being
disconnected from the adjoining sheave or shoaves, nor do I claim every
mode of coupling and uncoupling such sheaves, but what I consider as novel
and original, and therefore claim as the Invention secured to be by the
hereiu-before in part recited Letters Patent is,-
1st, the application and use of a sliding clutch for the purpose of coupling
and uncoupling the sheaves in differential pulley blocks, substantially in the
manner herein-before described and illustrated by Figure 1 of my Drawings.
2nd, the application and use of a sliding clutch for the purpose both of
coupling and uncoupling the sheaves in differential pulley blocks, and of
locking one of such sheaves, as herein-before described and illustrated by
Figures 11, and 12, and 13 of my Drawings.
3rd, the application and use of lateral cogs, pins, projections, or teeth on
one sheave in combination with a fixed stop or catch on the frame of the
pulley block, both for the purpose of coupling and uncoupling the sheaves in
differential pulley blocks, and simultaneously locking one of such sheaves

page_text: substantially as and for the purpose herein-before described and illustrated by
Figures 3, 4, 5, 6, 7, and S of my Drawings.
4th, the application and use to and in differential pulley blocks of a sliding
clutch or a sliding sheave in combination with a lever, cord, wedge, or spring
for producing the necessary notion for coupling and uncoupling, or for
coupling, uncoupling, and locking the sheaves, substantially as herein-before
described and illustrated by Figures 1, 2, 3, and 4 of my Drawings.
5th, the application and use in differential pulley blocks of one or more
spiral projections or threads formed on the spindle or axis of the sheaves, and
being in combination with inclined teeth or projections on one of the sheaves,
and on the frame of the pulley block, for the purpose both of coupling and
uncoupling the sheaves, and by locking one of such sheaves, as herein-before
described and illustrated by Figures 9 and 10 of my Drawings.
In witness whereof, I, the said Robert Anthony Hardcastle, have to
this my Specification hereunto set my hand and seal, this Eighteenth
day of September, One thousand eight hundred and sixty-six.
ROBERT ANTHONY HARDCASTLE. (L.s.)