Improvements in Hoisting Apparatus.
Year: 1887

page_text: Date of Application, 28th Jan., 1887
Complete Left, 26th Oct., 1887
Complete Accepted, 29th Nov., 1887
Improvements in Hoisting Apparatus.
I, THOMAS HENRY WARD of the Firm of Lee Howl Ward & Howl Engineers
Tipton Staffordshire do hereby declare the nature of this invention to be as
follows:-
My Invention has for its object chiefly the production of a Geared Differential
Chain Pulley Block such that without reducing its nominal or commercial size yet
that it shall be smaller, more compact & efficient & shall contain a greater purchase
power to boot.
I shall proceed to describe one form of my Invention as an example only consider-
ing it to be perhaps the best & simplest & I may point to several other modifications
afterwards.
I provide a set of Weston's Differential Chain Pulley Blocks complete but instead
of increasing the diameters of the top sheaves in order to obtain superior purchase
power I first reduce them & then to the side of one such sheave the smallest by pre-
ference I either cast or fix thereon & concentric with same a spur wheel preferably
an internal wheel of a shallow knuckle shaped tooth facing which & rotating upon the
same shaft I provide a spocket wheel with its corresponding hand chain.
This spocket wheel has an eccentric cast or fixed thereon which actuates another
spur wheel of unlike size & gearing in the former one as before mentioned as being
contained upon the differentials. Now there is a difference in the diameters of these
two knuckle spur wheels of say two teeth for example, & further to the latter spur
wheel as actuated by the spocket wheel eccentric I cast or fix thereon an arm which
extends preferably upwards & bears against some convenient part contained in the
frame.
Now although this latter wheel is of unlike size & preferably smaller than its corrc-
sponding one, yet by virtue of the eccentric actuating the same it is enabled to engage
the teeth of the latter when the one wheel lies within the other & since it cannoi
rotate by virtue of its arm abuting against some part contained within the frame or
else by the frame itself, when rotary motion is imparted to it by the spocket wheel, it
consequently gives motion to the differential wheels by an amount corresponding to

page_text: that of the difference between the number of the teeth contained in these said wheels
& thereby constitutes a substantial purchase power when considered in conjunction
with that of the differentials themselves.
I further provide a bracket or cross bar secured between the two sides of the top
frame the bottom side of which is shaped to serve as a stop thus preventing the
main chain riding on the top of its corresponding teeth accidentally or otherwise
whilst from it right & left & immediately over the spocket wheel an arm projects
partly embracing it preventing thereby the spocket chain from jumping out of its
path whilst further it may serve as the abutment to the arm of the spur wheel actuated
by the spocket wheel eccentric.
Instead of spur gear as before described bevel gear may be provided in which case
the eccentric will have to be provided angularity relatively to the axis of the main
shaft or pin sufficient to ensure the teeth clearing when disengaged & likewise the
direction of its arm may have to be modified somewhat.
Duplicate spocket wheel, eccentric, & spur or bevel gears may be likewise provided
upon the other side of the differentials if desirable.
I may provide also a chain guide serving to guide the spocket wheel endless
chain in entering such wheel & which consists of a spirally coiled bar or stout
wire coiled spring wise, the diameter of which is sufficient to contain the chain
freely inside, & the pitch of the spiral sufficient to ensure that it may be threaded
thereon even though it be endless. To one extremity of this guide may be affixed to a
radial bar preferably swivelling upon the main pin or better still the said leg may be
extended upwards & its extremity made to embrace & to swivel upon the said pin in
which case care must be taken to put such a bend in its length that the axis of such
coil shall be tangential to the periphery of the chain wheel itself or thereabouts
ensuring thereby that it will always remain so, whatever position it may acquire upon
the pin itself.
T1 of 1007

page_text: 1, THOMAS HENRY WARD, Engineer, 31 High Street, Tipton, Staffordshire, & late
of the Firm of Lee Howl Ward & Howl of Tipton, 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 object of my Invention, broadly speaking, is to obtain a more powerful set of
differential-chain-pulley-blocks & chains complete, without materially increasing, if at
all, either their bulk, weight or price.
I will describe the apparatus constructed according to my Invention with reference
to the accompanying "Drawings, in the which, & as nearly as possible, like letters
correspond to like parts throughout.
Figure 1 is a front sectional elevation of the top block only through line A B to be
found in the drawings. Figure 2 is a side sectional elevation, one half of which is
shown through line CD, & the other half through line E F looking towards the
spocket wheel side, with parts broken away in order to show the internal purchase
gear whilst it is unnecessary to show the hottom block since it is of the ordinary
type.
I provide a set of Weston's top & bottom differential-chain-pulley-blocks & chain
complete but instead of increasing the diameters of the sheaves in the top block in
order to obtain a superior purchase power, I first reduce them as shown at G₁ G₂
respectively; & to the side of one such sheave, the smallest, G, by preference, I pro-
vide, concentric thereto, a spur wheel G₁, facing which, & rotating upon the same
shaft H, I provide a spocket wheel J, with its corresponding hand chain Ja &
having an eccentric J, cast or fixed to the side thereto, which eccentric another spur
wheel K, surmounting it, & gearing with, & driving the former wheel G, as before
mentioned.
Now the driving spur wheel K, has an arm K, cast or otherwise fixed thereon,
extending preferably upwards, & having an extremity K, bearing & sliding
against some convenient part as an abutment, as L₁, at as great a radial distance
from the axis of the pin H as convenient, which abutment by preventing its rotation
insures that a much slower & more powerful one is imparted to the corresponding
driven wheel G, as a consequence of the ratio of the difference of the number of
teeth contained in those two wheels & the number containd in the larger one.
I may provide an improved safety guard M, for the chains G, immediately above
the respective differential wheels G₁ & G, containing it, & which is secured in, &
between the two side frames, preferably by merely letting its projecting lugs M, M, M,
into corresponding holes provided in them; & I may further provide that a spocket
chain guard M, M, may project on each side of the same immediately above its
corresponding wheel J..
The example as illustrated on Sheet 1 of the drawings has been taken from a 3 ton
block which has been preferably designed as being self-sustained, with 5 & 6 teeth &

page_text: with 12 & 14 in the differential & the spur wheels respectively. Being self-sustained,
it has furthur been designed with the arm K, duplicated on the other side of the
abutment, thus conveniently forming a bifurcated arm engaging the abutment L by
sliding contact at, & between its extremities K, K.
Although this arm may appear weak as seen in Figure 1 just where it bends to get
out of the spocket wheel, yet by reason of the fact that it is arched in the face view
as, & corresponding with the spocket wheel J, containing it, it thereby becomes a
source of strength rather than of weakness. Nor must it be forgotten that the stress
upon it, & upon the spur gear is not that mainly due to the entire load, but to the
difference of the leverage of the 2 half loads hanging from opposite sides of the
respective differential wheels.
Bevel-gear may be provided in lieu of the before mentioned spur-gear; but since it
produces a lateral twist upon the eccentric, & a lateral roll across the teeth, tending
chiefly to friction & to abrasion respectively, & is of greater bulk, it is by no means
preferable.
Figures 4 & 5 Sheet 2 represents for example a 2 ton block having such bevel-gear
marked K, & G, the bifurcated arm K, of which preferably engages the nut of the
hook N, as an abutment; whilst this block has been designed with a malleable-
cast-iron frame, in which case the cross bars M, M, serve as the necessary chain
guards.
I may provide, if desired, in either arrangement, a spocket-wheel-chain-guide M,
to each side of the wheel, consisting of a spirally coiled bar or stout wire coiled
spring-wise as seen in Figures 4, 5 & 6, the pitch, & the internal diameter of which
are sufficiently great to enable the endless chain being threaded or screwed & contained
therein, particularly as shown in Figure 6. Preferably it may swivel freely from
the main pin with the axis of its coils inclining relatively to its radial leg in such a
mannner as to point tangentially to the spocket wheel or thereabouts, ensuring thereby
that whatever radial position it may acquire relatively to the wheel, the axis of the
coil maintains its tangential position thereto. By duplicating it on the other side of
such wheel & at the extreme ends of the same bar, & by closing this bar, about mid-
way, into a groove provided round the end of the main pin as shown M, a cheap &
efficient pair of guides is provided, but the axis of the coils should be spread out
somewhat as shown beyond their own parrellel. As a further precaution (which I
consider unnecessary with so efficient a guide) a wire may be inserted down the coil
when the chain is in, with its extremities bent back to avoid slipping out, insures with
absolute certainty that no twisted link passes.
I consider the first arrangement of the apparatus as shown in Figures 1, 2 & 3 to be
the best, & I may state briefly that with the example given as a 3 ton block it
requires but 3 men to lift that load; that for a like strength, tonnage & power, it is
the cheapest & smallest extent; that its gear is provided within the frames & upon
the same pin or axle in such a manner that in the event of its breakage, the load
remains suspended, & may be lowered without danger by the apparatus as 記
"Weston's "block.
Having now particularly described & ascertained the nature of my said Invention,
& in what manner the same is to be performed, I declare that what I claim is :-
(1) In hoisting apparatus the combination with a pair of chain-differential-wheels
& a side-spur or bevel wheel (as the case may be) combined, of a corresponding spur
or bevel pinion geared thereto, surmounting & actuated by an eccentric projecting
from the inside of a spocket wheel, which pinion has its rotary motion arrested by its
projecting arm bearing, & reciprocally sliding, upon an abutment contained within or
about some part of the frame; & which spur or bevel wheel & differential wheels
combined, together with the spocket wheel & eccentric combined, rotate upon one &
the same pin or axle, substantially as & for the purposes herein before described
& illustrated in Sheets 1 & 2 respectively of the accompanying Drawings.
(2) In hoisting apparatus a chain bracket or crossbar spanning between, & supported
& secured by, the side frames, & consisting of a casting whose lower outline serves

page_text: as a pair of stops or guards to the chain contained upon the differential wheels
immediately below, & to each side of which crossbar a projecting arm is cast whose
lower & concave surface embraces the spocket wheel as a chain guide or guard also,
substantially as & for the purposes hereinbefore described & illustrated in Sheet 1 of
the accompanying Drawings.
(3) In hoisting apparatus a spocket wheel chain guide, duplicated or otherwise,
consisting of an openly coiled spiral bar or stout wire, substantially as & for the
purposes hereinbefore described & illustrated in Sheet 2 of the accompanying
Drawings.
(4) The several arrangements & combination of parts (with or without the chain
bracket as claimed in the second claiming clause, & with or without the spiral-chain-
guide as claimed in the third claiming clause, & with either a built up or a solidly
cast frame) constituting the hoisting apparatus, substantially as & for the purposes
hereinbefore described & illustrated in Sheets 1 & 2 respectively of the accompanying
Drawings.