IMPROVEMENTS IN LOWERING WEIGHTS BY MEANS OF CRANES, WINCHES, OR SIMILAR APPARATUS
Year: 1857

page_text: application for Letter's Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by William Thompson and Hamilton
Woods at the Office of the Commissioners of Patents, with their Petition,
on the 27th April 1857.
We, WILLIAM THOMPSON, Engineer, of Spring Gardens Engine Works,
Newcastle-on-Tyne, and HAMILTON WOODS, Engineer, of the same Place, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
LOWERING WEIGHTS BY MEANS OF CRANES, WINCHES, OR SIMILAR APPARATUS," to
be as follows:-
Our improvements consist in the application to the lowering of weights of
the principle of regulating the resistance of atmospheric air, by regulating
the exit of air from a vessel attached to a crane, or winch, or similar appa-
ratus. The application of this principle to the lowering of weights by means
of cranes, winches, or other similar machines may be made in various ways,
but the one herein-after set forth, as applied to a steam crane or winch, is
the application we prefer.
The accompanying Drawing shews a part of a steam crane or winch with
two outside steam cylinders giving motion to crank pins fitted to cast-iron
discs keyed on to the ends of the first motion shaft of a crane or winch,
as shewn in the Drawing. These cylinders are fitted with ordinary slide
valves worked by eccentrics in the usual manner. A pipe A is connected to
each slide case and attached to a cock B; C, C, are the steam cylinders.
When a weight is being lifted by means of steam acting upon the pistons

page_text: D, D, the cock B is closed. When the weight is to be lowered, the cock B
is opened so much as to allow the weight to descend at the required velocity.
The method of lowering is as follows:-When the weight is raised to the
height required, the steam communication between the steam cylinders C, C,
and the boiler is cut off and the cock B is opened, the weight hanging there
overcomes the resistance offered by the toothed gearings, pistons, &c., and
makes the crane or winch barrel and gearing rotate, causing the steam
pistons D, D, to make reciprocal motions. This reciprocal action of the
pistons D, D, causes alternately a vacuum in the cylinders C, C, above and
below the pistons D, D. The air passing through the steam exhaust port G
fills the cylinder space alternately above and below the pistons D, D, and is
forced out alternately through E and F, the steam ports of the cylinder, and
always through the cock B, the velocity of the exit of the air being
regulated by the opening or closing of the cock B, and by such means of
regulating the weight is either lowered slowly or quickly. This means of
lowering weights may be used either separately from or in connection with
-a break.
We do not confine ourselves to the application of this Invention to steam
'cranes or winches, but we also consider as novel tho application of this
Invention to ordinary cranes or winches, and similar apparatus, to which
a cylinder and valve may be attached for the express purpose of pumping air;
the discharge or exit of such air to be regulated by means of a cock or
valve, as herein-before set forth.