IMPROVEMENTS IN BRAKES OR THE APPLIANCES FOR ARRESTING THE DESCENT OF THE LOAD IN LIFTING APPLIANCES, SUCH AS CRANES, CRAB WINCHES, OR WINDLASSES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by George Sonnenthal at the Office of the
Commissioners of Patents on the 25th November 1878. A communication
from abroad by Otto Stegmeyer, Engineer, of Charlottenburg, in the Empire of
Germany.
GEORGE SONNENTHAL, Engineer, of 2, Lambeth Hill, Queen Victoria Street, in
the County of Middlesex. "IMPROVEMENTS IN BRAKES OR THE APPLIANCES FOR
ARRESTING THE DESCENT OF THE LOAD IN LIFTING APPLIANCES, SUCH AS CRANES,
CRAB WINCHES, OR WINDLASSES." [A communication from abroad by Otto
Stegmeyer, Engineer, of Charlottenburg, in the Empire of Germany.]
This Invention relates to an improved crank handle or lever, represented in the
annexed Drawing, Figures 1, 2, 3, and 4, for windlasses, cranes, and the like, by
means of which the dangerous whirling round of the crank handle when lowering
the load is avoided, and at the same time means are provided for applying a brake
in a certain and easy manner as well as for arresting and maintaining the load at
any desired elevation.
This improved crank is composed of a brake wheel keyed upon the ordinary
shaft of a windlass or other like hoisting apparatus, upon the nave of which wheel
a circular drum or case is mounted so as to be capable of rotating upon it and pro-
vided on its periphery with notches or ratchet teeth engaging with a pawl and
carrying a rocking pin of peculiar shape upon which the lever or crank proper is
fixed. A brake block or wedging piece, Figure 4, actuated by the lever and capable
of being pressed against the brake wheel serves to force round the brake wheel and
shaft as well as for lowering the load. This piece is also capable of being adjusted
by suitable screws.
The prolongation of one end of the lever serves as a counterweight to the opposite
extremity as well as for enabling the brake block to be applied automatically by
means of a spring.
The notches or ratchets on the case or drum are so formed as to be capable of
engaging with a double acting pawl when the shaft is turned in either direction.
When it is desired to turn the handle and wind up the load in the direction shown
by the arrow, for example, as in Figure 3, and the pin of the pawl is attached to a

page_text: suitable part of the framework of the crane or windlass, a pin covered with india-
rubber is inserted in the framework between the branches of the pawl so as to limit
its motion. The rubber is provided for the purpose of obviating the rattle of the
pawl, being so placed that the upper branch of the pawl rests upon the rubber
and prevents the other branch from coming in contact with the bottom of the
notch.
When it is desired to wind up the load the crank lever is turned in the proper
direction whereby the brake block becomes jammed between the brake wheel and
the pin on which the crank lever is fixed. Consequently the brake wheel case and
lever are rigidly connected and compelled to move together. According as the
power applied to the lever is increased as required by the resistance of the load, so
the brake block is more powerfully jammed against the brake wheel. As the pawl
will only allow the rotation to take place in one direction by engaging with the
notches on the drum or case the brake block may be released or taken off by turning
the lever backwards, so that the brake wheel is then free to turn and let down the
load.
The speed with which the load is allowed to descend may then be regulated or it
may be arrested and maintained stationary at pleasure by pressing the lever or its
prolongation more or less powerfully backwards. The load will also be supported
with ease and certainty by a short forward motion of the lever in the direction of
the arrow, as well as when the lever is suddenly let go as the action of the spring
on the prolongation of the lever, as well as that of the load itself ensure the forcible
application of the brake block against the brake wheel.