Automatic Brake for Hoists and Kindred Purposes.
Year: 1897

page_text: Automatic Brake for Hoists and Kindred Purposes.
We, WILLIAM THOMAS EADES, of 40, Floodgate Street, Birmingham, in the County
of Warwick, Engineer, and THOMAS MATTHEWS, of 47, Warwick Street, Leamington,
in the County of Warwick, Coal Merchant, do hereby declare the nature of this
invention to be as follows:-
My invention consists of an automatic brake for hoists & kindred purposes so
constructed that while it admits of a shaft having a free circular motion in either
direction if driven from the one end is incapable of circular motion in either direction
by pressure from the opposite end.
In constructing an automatic brake in accordance with my invention I mount a
circular shaft in a suitable bearing and on one side of such bearing is formed a circular
chamber, fitting the interior surface of this chamber is a cam & wedge, on the said
shaft a radial arm is formed which drives the inner side of a stud formed upon the
said cam or if moved in the opposite direction drives the inner side of a stud formed
upon the wedge, in either case causing the cam & wedge to move with an expanding
action and to lock themselves within the circular chamber formed for their reception
and preventing any circular motion. On the driving end of the said shaft I mount
a pulley or lever with a projection formed upon it so shaped that when it is revolved
it presses against first the outer side of the stud formed upon the circular cam or the
outer side of the stud formed upon the wedge in either case relieving any pressure
and at the same time engages with the radial arm and carries the shaft freely round
in either direction.
Automatic Brake for Hoists and Kindred Purposes.
We, WILLIAM THOMAS EADES, of 40, Floodgate Street, in the City of Birmingham,
Engineer, and THOMAS MATTHEWS, of 47, Warwick Street, Leamington, in the County
of Warwick, Coal Merchant, 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 :-
This invention relates to brakes or load-sustaining means for pulley-blocks, hoists,
lifts, crabs, cranes, capstans, winches, windlasses and like mechanical appliances for
raising, lifting and otherwise dealing with heavy weights and has for its object, an
automatic load sustainer.
According to my improvements, a mechanical advantage is obtained, inasmuch as
I am enabled to transmit the necessary power for raising a load through the medium

page_text: of spur gearing with a great reduction of friction, hence a corresponding reduction in
the amount of power required to raise a given weight.
Figure 1 of the accompanying drawings represents a section, taken immediately
inwards of the inside face of the lifting wheel, of a double-lift pulley block, provided
with an automatic brake or load-sustainer, so constructed that whilst admitting of
the main shaft having a free circular movement in one or other direction for raising
and lowering when turned or driven from the one end, viz., the hand wheel end, the
said shaft is rendered incapable of rotating in either direction on the application of
pressure or driving force at the opposite or load wheel end. This view shows the load
sustaining device in operation.
Figure 2 is a complete vertical section of the said pulley block, upon the dotted
lines x Figure 1.
Figure 3 is another section, taken upon the same line as the sections shown. in
Figure 1 but with the brake out of action and looking in the reverse direction, viz.,
towards the inside face of the lifting wheel.
Figure 4 represents a like sectional view as Figure 1, but showing the load
sustainer off or out of action.
-
Figure 5 represents the cam and wedge sections of the expanding lock or clutch
part of the brake or load retainer, said view showing the outward faces of said sections
and the studs, or lugs, located thereon.
.
The same letters of reference indicate corresponding parts in the several figures of
the drawings.
a is the framing of the block, supported or hung by the swivelling hook a', (or by
other means) and b is a circular shaft or main axis having ends b', 62, turning within
bearings a², on one side of which, a circular chamber ³, adapted to contain the
expanding friction clutch or brake mechanism, is formed. Said brake mechanism
comprises a cam shaped block c, loosely mounted, with a clearance for lateral play,
upon the sleeve of the axle bearing located axially within the interior of the chamber a³,
whilst lying within the space comprehended between the periphery or face of the cut-
away part c², of the said cam, and the inside periphery at, of the said chamber a³, is a
wedge piece d. The outer faces of the said cam and wedge are respectively provided
with an outwardly-projecting lug or stud c¹, d¹, arranged both at about the same
distance from the centre of the axis or shaft b, but separated from one another, by a
short interposed arm e, rotating with and made fast to the said shaft.
f is a taking-off and driving stud, mounted upon the inner face or side g¹, of the
hand wheel g, loose upon the axle b, and adapted to communicate lifting or lowering
motion imparted to the said wheel through a chain as usual by driving against the
back of either the stud c¹, of the cam or the stud, of the wedge, which. said stud in
turn drives round the radial arm e and the axle b, which has a pinion 67, gearing
with a toothed wheel h, whose pinion h¹, meshes with the teeth of an inside tooth
annulus or box wheel i, having the load wheel j, formed or mounted upon its
outer side. The cam c, and its locking wedge d, are carried round bodily in
one or other direction with the axle, by the driving stud f, impinging against the
wedge stud d', (when the parts are in the positions represented in Figures 3 and 4
as in raising) which impinges against the radial axle arm e and this in turn bears
against the stud c¹, and carries round the cam c.
During ordinary raising or lowering, the peripheries or outer edges of the expanding
parts of the braking expedient are carried round with the axle, clear of the inside
walls of the box or chamber wherein they are located but immediately the application
of driving power upon the hand wheel is relieved, the back pressure of the load
exerts itself through the load wheel and gear upon the load end of the axle which
transmits its motion to the radial arm, which acts upon the inside of the lug or snug
of either the cam or wedge, when an expanding action is set up and up and the
opposed surfaces of the cam and wedge and the chamber are brought into intimate
contact, and through their frictional adhesion and jambing action, the load is
automatically sustained or braked.
4
It is understood that the load pinion will set up the jambing action in whichever

page_text: direction it moves, and that the hand wheel will contract and release the clutch or
take off the brake, when rotated in either direction, so as to give a double sustaining
motion.
The pinion at the lifting end of the main axle may be made to engage with any
type of epicycloidal or other modifying gearing, or its place may be taken by a chain
wheel to lift direct.
The application of my invention to load sustainers for pulley blocks, hoists, lifts,
crabs, cranes, capstans, winches, windlasses and like mechanical appliances for
raising, lowering and otherwise dealing with heavy weights differs in no essential
respect from its application to pulley blocks as herein described.
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 :-
•
First An automatic brake or load sustainer for hoists and kindred purposes,
having brake mechanism put into operation by motion transmitted through the load
end of the axle, to an arm or equivalent coming between, and operating upon to
expand the segments of a braking expedient or friction clutch device.
Secondly-In an automatic brake or load sustainer for hoists and kindred
purposes, communicating motion for taking off the brake and also for driving, by a
stud or equivalent upon the hand wheel and operating to close together the segments
of the expanding friction clutch or braking device, and communicating driving
motion through them to the axle, or axle arın, of the raising and lowering gear or
mechanism.
Thirdly: An automatic brake or load sustainer for hoists and kindred purposes,
consisting of a clutch, comprising a cam and a wedge, located within a box or chamber
and expanded by an arm carried upon, and receiving its braking motion from the
load end, of an axle, and closed or contracted together by the motion of a hand
wheel through the medium of a stud or equivalent upon the inner face thereof,
substantially as described and set forth.
Fourthly The improvements in, and the general construction, arrangement and
combination of the parts of, automatic brakes or load sustainers for hoists and kindred
purposes, substantially as described and set forth.
Dated this 1st day of October 1897.
WILLIAM THOMAS FADES,
THOMAS MATTHEWS,
By Henry Skerrett,
24, Temple Row, Birmingham, Agent for Applicant.