Improvements in Self Sustaining Mechanism for Hoisting Machinery.
Year: 1898

page_text: Date of Application, 31st May, 1898-Accepted, 24th Sept., 1898
COMPLETE SPECIFICATION.
Improvements in Self Sustaining Mechanism for Hoisting Machinery.
FREDRICK HENRY ROYCE and ERNEST ALEXANDER CLAREMONT, both of Cooke
Street, Hulme, Manchester, in the County of Lancaster, Engineers, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to improvements in brakes and clutches for controlling
the load on cranes, hoists and lifting machinery generally. Heretofore the brakes
used on cranes, hoists, and other lifting machinery have had to be controlled
by the person in charge of the machinery.
The object of this invention is to provide a means of overcoming any objection
to leaving the application of the brake to the person in charge and to render the
application of the brake altogether automatic in its action and dependent on
the load to be sustained.
In applying our invention to cranes and lifting machinery generally we use the
following apparatus which we will describe by means of the accompanying
drawings.
tion.
Figures 1 and 2 are respectively a sectional front elevation and side eleva-
a is an annular ring which is kept concentric with the shaft f (which shaft
is geared to the load) by means of a boss n. The annular ring is fixed rigidly
to the framework of the crane or other machine by means of two snugs o which
prevent it from turning round. The lever c, which we term the load lever, is
firmly keyed on to the shaft f and is provided with a toe p which is pressed against
the lever e owing to the load tending to turn the load lever c in the direction s.
The lever e is pivoted to the head of the friction band bat j and the lever dis
pivoted on the load levere at k. The pressure of the toe p on the lever e is trans-
mitted by means of the levers e and d and the link h to the screw i and causes
it to press against the tail of the friction band b which causes the friction band b
to be expanded and consequently grip the annular ring a and sustain the load.
In order to put an initial pressure on the band b there is a spring g which presses
against the lever e and the load lever c. The actuating pulley or wheel / which
may be driven by any suitable means runs loose on the shaft f and is provided
with two driving pins r and q: When this pulley or wheel is driven in the
directions the pin r presses against the lever e and releases the tail of the friction
band b and then moves the whole system of levers in the directions and allows the
load to descend by its own weight; if the load is not heavy enough to descend
by its own weight it is driven down by the pin r continuing to drive the levers in
the direction s.
Also when the wheel is driven in the direction the pin g presses against the
load lever c and this takes the pressure of the too off the lever e and again
releases the friction band b and by continued movement in the direction t raises
the load. The friction band and the whole system of levers at the same time
being freely moved in the same direction. Should now the driving wheel / be