IMPROVEMENTS IN THE CONSTRUCTION OF LIFTS AND HOISTS, APPLICABLE ALSO OTHER SIMILAR MACHINERY OR APPARATUS FOR RAISING OR LOWERING LOADS
Year: 1881

page_text: LETTERS PATENT to John Marsh Day, William Robert Green, and Henry
Claude Walker, of Falmouth Road, Great Dover St., Boro', in the
County of Surrey, Engineers, for an Invention of
TIDMA
A
Harama ADDLICARLE
IMPROVEMENTS IN THE
ALSO TO OTHER SIMILAR
PROVISIONAL SPECIFICATION left by the said John Marsh Day, William
Robert Green, and Henry Claude Walker at the Office of the Commissioners
of Patents on the 29th April 1881.
JOHN MARSH DAY, WILLIAM ROBERT GREEN, and HENRY CLAUDE WALKER, of
Falmouth Road, Great Dover St., Boro', in the County of Surrey, Engineers.
"IMPROVEMENTS IN THE CONSTRUCTION OF LIFTS AND HOISTS, APPLICABLE ALSO
OTHER SIMILAR MACHINERY OR APPARATUS FOR RAISING OR LOWERING
LOADS."
TO
Our Invention consists in providing means whereby the cage of a lift or other
equivalent load may be raised or lowered with greater safety and ease than by the
mechanism at present employed for this purpose.
With this object we construct a frictional break consisting essentially of a disc
the periphery of which has cut or otherwise formed thereon a V shaped groove, in
which two or more detents or pawls are arranged to work. The said disc is keyed
on to the hauling shaft of the winch or other winding gear, whilst the detents are
pivoted upon a second disc or drum enclosing and free to revolve upon the former
or grooved disc. Suitable springs are arranged within the disc or drum for the
purpose of keeping the detents or pawls within the groove, and a stop is provided
for each to bear upon when in gear. Encircling this latter disc or drum is an
ordinary break strap, one end of which is secured to the cross timbers or other
convenient part of the framing, the other being attached to a lever carrying at its
outer end a counterweight suited to the load. At the extreme end of this lever is

page_text: secured a cord whereby the lever can be raised and the break released at any
moment for the purpose of lowering the load.
Upon the accompanying Sheet of Drawings,-
Figure 1 is a view of the interior of the disc or drum, showing position of inner
disc together with the pawls and springs.
Figure 2 is a cross section through the same.
Figure 3 being a side elevation showing the general arrangement and application
of our Invention to a hoist, and
Figure 4 a plan of the same.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Marsh Day, William Robert Green, and Henry Claude
Walker in the Great Seal Patent Office on the 27th October 1881.
JOHN MARSH DAY, WILLIAM ROBERT GREEN, and HENRY CLAUDE WALKER,
of Falmouth Road, Great Dover Street, Boro', in the County of Surrey, Engineers.
IMPROVEMENTS IN THE CONSTRUCTION OF LIFTS AND HOISTS, APPLICABLE ALSO
OTHER SIMILAR MACHINERY OR APPARATUS FOR RAISING OR LOWERING
LOADS."
TO
Our Invention relates to improvements in the construction of lifts and hoists
applicable to other similar machinery or apparatus for raising or lowering loads,
whereby the cage of a lift or other equivalent load may be raised with great safety
and ease, be instantaneously arrested at any point in its descent, and be lowered
from such point of suspension with great facility.
With this object we adapt to the lift, hoist, or other machine or apparatus for
raising and lowering loads, an improved frictional brake consisting essentially of
a disc the periphery of which has cut or otherwise formed thereon a ✓ shaped
groove, in which two or more detents or pawls are arranged to work. The said
disc is keyed on to the hauling shaft of the winch or other winding gear, whilst
the detents are pivoted upon a second disc or drum enclosing and free to revolve
upon the former or grooved disc. Suitable springs are arranged within the disc or
drum for the purpose of keeping the detents or pawls within the groove, and a
stop is provided for each to bear upon when in gear.
.
Encircling this latter disc or drum is an ordinary brake strap, one end of which
is secured to the cross timbers or other convenient part of the framing, the other
being attached to a lever carrying at its outer end a counter-weight suited to the
load. At the extreme end of this lever is secured a cord whereby the lever can
be raised and the brake released at any moment for the purpose of lowering the load.
Our improvements will be more readily understood by reference to the
accompanying Sheet of Drawing, upon which
Figure 1 is a view of the interior of the disc or drum, showing position of inner
disc together with the pawls, springs, and break-strap.
Figure 2 being a cross section through the same.
Figure 3, a front view or elevation illustrating the application of the brake to
an ordinary hoist.
Figure 4 being a side view of the same.
Figure 5 shows the application of the brake to a single overhead crane or lift
and
Figure 6 is a side view of the same..
Similar letters refer to similar parts in each of the Figures respectively.
A, hauling shaft.
B, grooved disc keyed on same.
C, groove.
D, outer wheel or drum.
E, E, detents or pawls.
F, F, springs for pawls.
G, stops for pawls.
H, break strap.
I, lever for same.
K, counter-weight.
L, hand cord.
M, hauling wheel.
N, pinion.
O, countershaft.
P, toothed wheel in gear with pinion.
Q, load wheel.
R, hauling rope.

page_text: .
The action is as follows:-Upon motion being imparted in the direction indicated
by the arrow to the shaft A for the purpose of raising the cage or load the disc B
will be caused to revolve, whilst the outer wheel or drum D, being held by the
pressure of the weight K' acting through the lever I and strap H, remains stationary,
the pawls E running freely in the groove C. Should the above motion however
be reversed the pawls E, E, raised by' the friction instantly become locked within
the groove C, and bearing upon the stops G thus effectually hold, the disc B and
with it the shaft A from revolving, whereby the descent of the cage or load is
prevented.
.
From the above it will be seen, that in order to lower the cage or load all that.
is necessary is for the attendant to raise the lever I by means of the cord L, when
the wheel D, being freed from the grip of the strap E, at once yields to the pressure
of the pawls E and revolves, together with the disc B and shaft A.
Having now described and ascertained the nature of our said: Invention, and in
what manner the same is or may be performed,
We claim as secured to us by the hereinbefore in part recited Letters Patent,——
The use in lifts, hoists, and other similar machinery or apparatus for raising or
lowering loads, of the frictional brake hereinbefore described and shown, Figures 1
and 2 of the accompanying Sheet of Drawing.
In the said frictional brake the use of the grooved disc B, in combination with
the detents or pawls F, these latter being operated to arrest and liberate the said
disc, substantially as and for the purposes hereinbefore specified.
The application of our improvements as shown, Figures 3, 4, and 5 of the
accompanying Sheet of Drawing.
In witness whereof, I, the said Henry Claude Walker, for myself and on
behalf of my co patentees, have hereunto set my hand and seal, this
Twenty sixth day of October, in the year of our Lord. One thousand eight
hundred and eighty one.
HENRY CLAUDE WALKER. (L.S.)
Witness,
ALFRED GRANT,
Clerk to Messrs. R. Waygood & Co.