An Improved Brake for Rotary Shafts subject to Endways or Axial Pressure.
Year: 1892

page_text: Date of Application, 4th Mar., 1892-Accepted, 9th Apr., 1892
COMPLETE SPECIFICATION.
An Improved Brake for Rotary Shafts subject to Endways or Axial
Pressure.
We, ARNOLD GOODWIN, and ARNOLD GOODWIN the younger, both of
56 Sumner Street, Southwark, in the County of London, Engineers, do hereby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:- -
This invention has reference to the use in conjunction with a rotary shaft subject
to endways or axial pressure, of an improved construction of brake for permitting
of the shaft being freely rotated in one direction, but which will be automatically
brought into action to arrest or retard the rotation of the shaft in the opposite
direction.
And in order that the nature of this invention may be readily understood and
carried into practical effect we will proceed to describe the same by aid of the
accompanying drawings in which
Fig. 1 shews partly in elevation and partly in longitudinal section, a rotary shaft
with the improved construction of brake applied thereto.
Fig. 2 is a sectional elevation thereof on the linear Fig. 1.
a is a rotary shaft, as for example the worm-shaft in a pulley block, the rotation
of which in one direction is to be arrested or retarded. This shaft which when in
use is constantly subjected to end ways pressure acting in the direction of the
arrow 1, is formed or provided with a conical collar that enters a corresponding
conical collar c formed in one with a sleeve d. is a conical cap of suitable
material such as wood or leather arranged between the opposite conical surfaces of
the metal collars b and c. This cap serves to prevent undue friction between the
collars, and consequent seizure, and by making the wearing surfaces of the collars
of conical form and arranging them concentrically as shewn, the wear of these
surfaces is rendered more uniform than is the case when the collars are formed
with flat sides only arranged side by side as in previous constructions of brake
apparatus for shafts of the kind referred to. The collar c is formed externally
with ratchet teeth with which engages a spring pawl g to prevent rotation of the
sleeve in one direction. The sleeve d and collar c are free on the end a¹ of the
shaft so as to turn therewith by endways pressure operating on the friction surfaces
when the shaft is turned in one direction, but so that the said end a can turn
within it when rotated in the opposite direction and the sleeve and collar are held
stationary by the pawl. The sleeve is closed at its outer end and bears against a
pivot carried by a bearing i within which the sleeve is mounted to turn. When
the arrangement described is in use, the collar is forced to the right, and acting
through the cape and collar c, forces the end of the sleeve against the pivot hi.
When the shaft is rotated in the direction of the arrow 2, the sleeve will rotate
with it, but when the force acting to turn the shaft in the direction mentioned,
ceases, and the shaft commences to turn in the opposite direction, the pawl g will
prevent the backward rotation of the sleeve, and the friction between the cape and
the collar, or collars and c, will act to retard rotation of the shaft and it
may be to stop it if the turning force be insufficient to overcome the friction set up
between the parts mentioned.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The improved brake for rotary shafts subiect to endwors Araxial Pressure

page_text: wherein a cap of suitable material such as wood or leather is interposed between a
conical collar on the shaft, and a corresponding conical collar on a sleeve adapted
to rotate in one direction only, substantially as described and shewn for the purposes
specified.
Dated this 4th day of March 1892
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.