An Improved Automatic Controlling Brake for Hoists, Lifting Appliances, and the like.
Year: 1894

page_text: Date of Application, 15th May, 1894
Complete Specification Left, 13th Feb., 1895-Accepted, 23rd Mar., 1895
PROVISIONAL SPECIFICATION.
An Improved Automatic Controlling Brake for Hoists, Lifting
Appliances, and the like.
We, WILLIAM HENRY CRANSTONE, of 25 High Street, Hemel Hempstead,
in the County of Hertford, Engineer, and WILLIAM ROBERT HAY, of
13 Christchurch Road, Hemel Hempstead aforesaid, Engineer, do hereby
declare the nature of our said invention to be as follows:-
The object of our invention is to construct an improved safety brake apparatus
for hoists lifting appliances and the like, for the purpose of more effectually
controlling such apparatus.
Our invention consists of a stationary shell casting, fixed to any suitable part
of the framing of the machine, concentrically with the revolving shaft passing
through the same. Also of a cylindrical brake pulley or drum, fast ou the shaft,
and open at one end, truly turned inside and outside. Outside the brake pulley
we fit an improved strap brake, the lever of which acts upon an inclined face upon
a lug.
Inside the brake pulley is a truly turned brake ring, loosely held by a stud pin
through a projection on the inside of the ring, and secured concentrically with the
shaft to the first named shell casting. Diametrically opposite to this stud pin, the
ring is at its periphery bored and split. An elliptical plug is inserted therein
attached to which is a segmental weighted lever, with a roller secured to the same.
This lever is kept in a normal position by a coned disc on the shaft. Fixed on the
shaft, and in close proximity to the brake, we fix a governor, which is held
diagonally to the shaft by an adjustable spring. Connection is made from the
governor to the cone disc by a link. The function of the governor is such that
should the shaft by any cause or means, revolve at an excessive speed, the centri-
fugal action of the governor will cause the cone disc to be moved from under the
lever of the internal brake, by which action the lever is made to give a partial
rotation to the elliptical plug, thereby expanding the brake ring with sufficient
frictional contact on the brake pulley to prevent further rotation of the shaft.
Dated 15th May 1804
An Improved Automatic Controlling Brake for Hoists, Lifting
Appliances, and the like.
We, WILLIAM HENRY CRANSTONE, of 25 High Street, Hemel Hempstead,
in the County of Hertford, Engineer, and WILLIAM ROBERT HAY, of
13 Christchurch Road, Hemel Hempstead aforesaid, Engineer, do hereby
declare the nature of our 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 our invention is to construct an improved safety brake apparatus

page_text: for hoists, lifting appliances, and the like, for the purpose of more effectually
controlling such apparatus.
And in order that our said invention may be particularly described and
ascertained, reference is hereby made to the accompanying drawings, in which
similar figures of reference indicate corresponding parts.
Fig. 1 is a horizontal section of our invention, and Fig. 2 is a vertical section on
the line 3-4 of Fig. 1.
Our invention consists of a stationary shell casting 5, fixed to any suitable part.
of the framing of the machine, concentrically with the revolving shaft 6 passing
through the same. Also of a cylindrical brake pulley or drum. 7, fast on the
shaft, and open at one end, truly turned insid: and outside. Outside the brake
pulley 7 we fit a strap brake 8. The forked end of the lever 9 is pivoted at 10
to the lug 11, and the curved face of the lever, between the fork acts upon the
inclined face of the lug 12, whereby the brake 8 is readily applied and released.
Inside the brake pulley 7 is a truly turned brake ring 13, loosely held by a stud.
pin 14, screwed into the shell casting 5. The stud pin 14 projects into an elliptical
slot formed in the projection 15, integral with the brake ring 13, whereby the
brake ring 13 is prevented from turning round, and thereby it is secured in a
concentrical position. On the opposite side to the stud 14 the ring 13 is bored
and split to receive an elliptical stud 16. This stud 16 is capable of partial
rotation upon its centre, being fixed to a segmental weighted lover 17, the weight
being partly supplied by a roller 18, turning on a pin attached to the lever 17, and
partly by the weight of the lever itself. 19 is a coned disc, capable of sliding
longitudinally upon the shaft 6, its position being governed by the position of a
centrifugal governor 20, pivoted to the shaft at 21. This governor is pressed to a
diagonal position by the spring 22, regulated by a screw 23, fitted to the driving
pulley 24, keyed to the shaft 6. 25 is a feather or key, sliding in a groove formed
in the shaft, one end of the feather 25 being fixed to the cone 19; the other end
has a slotted link 26, in which a pin 27, attached to the governor, works.
In case the shaft, from any cause, should revolve at an excessive speed, the
governor 20 assumes a position of greater angularity relatively to the shaft. This
movement causes the cone 19 to travel towards and into the stationary shell 5.
The lever 17 and roller 18 then falls towards the shaft, in consequence of the
reduced diameter of the cone upon which the roller 19 rests. The lever 17 at the
same time rotates the elliptical stud 16, and thereby expands the internal brake
ring 13, with sufficient force to produce the required frictional contact with the
brake pulley or drum 7, to prevent further rotation of the shaft.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
The improved automatic controlling brake for hoists, lifting appliances and the
like, substantially as herein before described and illustrated by the drawings.
Dated 6th February
1002
1000x
GEO. DOWNING,
8, Quality Court, London, W.C., Agent.
GEO.
DOWNING,
8, Quality Court, London, W.C., Agent.