IMPROVEMENTS IN MACHINERY FOR LOWERING COALS AND OTHER MATERIALS IN WAGONS AND OTHERWISE.
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by John Dunn at the Office of the
Commissioners of Patents on the 19th March 1880.
JOHN DUNN, of South Hetton, in the County of Durham, Colliery Engineer.
"IMPROVEMENTS IN MACHINERY FOR LOWERING COALS AND OTHER MATERIALS IN
WAGONS AND OTHERWISE.
"
My Invention consists in improvements in the lowering machinery commonly
called a "drop," on the rivers Tyne and Wear, and elsewhere, by which coals and
other materials are lowered from quays and other elevations.
I use an eccentric pulley, working in the middle of a hollow shaft, which works
round the ordinary shaft of the brake wheel or plane. This eccentric wheel is
worked by a weight attached to it by a flat chain, which weight exceeds the weight
of the truck and the ordinary cradle which holds it, but is less than that weight
plus the coal or other material.
Attached to the hollow shaft are two pulleys which are made a part of the brake
plane, the whole of these three pulleys being worked by the ordinary strap brake
and the handle in the usual manner.
Attached to the two brake pulleys are two flat chains which are connected with
the cradle holding the truck or material. Each of these chains passes over a pulley
which is fastened to that part of the beam called the goose neck, which is a part of
the arm, close to the extremity of which the cradle is now fixed, and holds the
cradle in its position in the goose neck, which has an open mouth to receive
the hanging bar of the cradle instead of holding it in a fixed position as at
present.
These chains cannot work until the truck is lowered to the level to which the
present drops will carry it and the cradle; the truck (if used) and the coal or other
material (being together of greater weight than the weight) then lower themselves
into the hold of a ship or any other place, and by the use of the brake lever the
whole of the cradle truck (if any) and coal, or other material, can be stopped at
any stage. By the present ordinary application of the brake when the truck is
emptied, or the load otherwise delivered, the weight being heavier than the cradle
and the truck (if any) less the coal or other material, draws the bar of the cradle
(with the truck in the cradle) by means of the eccentric wheel, back into the mouth
of the goose neck, and thence the truck is raised to the level of the quay or
other elevation by the assistance of the present process of a balancing weight.

page_text: Attached to the arm of the goose neck, close to the pulley and plane, which are
fastened to the hollow shaft, is a fall catch which holds the pulley on the hollow
shaft so as to produce the effect of the present brake plane and fast shaft, but when
the drop has lowered the truck or weight to the distance now attainable by the
present drops, this fall catch has, by the force of gravitation, loosened its hold on
the catch pin in the pulley, so that the weight and eccentric wheel have full play.
In order to retain the goose neck in its position until the hanging bar of the cradle
has returned into the mouth piece of the goose neck a footsneck is made to catch
the arm of the goose neck until the hanging bar is in position, and this footsneck
is worked by the man who holds the brake lever without leaving his ordinary
place.
By the use of my Invention, as above described, coal and other material can be
lowered in its waggon or carriage, or in bulk, to any point which may be required,
and thus the great breakage and damage which now arises through its being
allowed to fall from the level to which the present drops will lower the truck into
the hold of the ship or other low place is altogether avoided, and thus the value of
the coal or other material will be greatly increased.