IMPROVEMENTS IN AND RELATING TO BRAKES FOR GAS OR OTHER ENGINES to be as follows:
Year: 1884

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I, JOHN GOOCH ROCKHILL, of Bury Street in the City of London, Engineer,
do hereby declare the nature of said invention for "IMPROVEMENTS IN AND
RELATING TO BRAKES FOR GAS OR OTHER ENGINES to be as follows:-
"
The chief object of my invention is to provide a gas engine with means for
arresting the motion of the fly-wheel and other parts. But my said invention
may if desired be applied to other engines.
It is well known that when a gas-engine is working at a high speed and the
supply of gas thereto is shut off, the fly wheel and other parts continue to move
for a considerable period of time. Great inconvenience is experienced by reason of
this fact and in some cases considerable risk of accident arises therefrom. But by
my invention, after the supply of gas to the engine is shut off the motion of the
said fly-wheel and other parts can be arrested in a very short space of time, or the
said fly-wheel and other parts can be stopped if necessary without shutting off
the supply of gas.
In carrying my said invention into practice I arrange a brake in combination
with the fly-wheel of a gas-engine, and provide the following mechanism for
actuating the said brake, that is to say:-I fix to one of the flanges of the bed-
plate a bar or rod of iron or other suitable material, which is turned at one end to
serve as a pivot or fulcrum for the brake which consists essentially of a metal strap
lined with leather or other suitable material to increase the friction between the
said strap and the fly-wheel. This strap partially surrounds the periphery of the
fly-wheel at its lower part, and the free end of the said strap is made with a
projection in which is inserted an adjustable eye-bolt or stud. A hand lever is
pivotted upon a stud fixed in a bracket which is secured to the bed-plate or frame
of the engine. The short arm of this lever is coupled to the said eye-bolt so that
by moving the said lever in one direction, the aforesaid strap will be forced against
the periphery of the fly-wheel. The long arm of the said lever slides upon a
quadrant provided with a series of screw threaded apertures in either of which a
screw-pin can be inserted to limit the movement of the said lever. The said lever
may if desired be provided with a pawl adapted to engage with teeth upon the

page_text: said quadrant so as to hold the said lever in any desired position. Or I may
provide other suitable means for effecting this object, for example, a spring bolt
similar to that ordinarily employed in combination with the levers of reversing
gear.
In applying my invention to an ordinary Crossley's gas-engine I can secure the
apparatus to the bed-plate without the necessity for drilling more than one hole
therein.
I, JOHN GOOCH ROCKHILL, of Bury Street, in the City of London, Engineer
do hereby declare the nature of my invention for "IMPROVEMENTS IN AND
RELATING TO BRAKES FOR GAS OR OTHER ENGINES" and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The object of my invention is to provide means whereby the motion of the fly-
wheel and other parts of an engine may be immediately arrested when necessary
or desirable. My improvements, although chiefly designed to be applied to gas-
engines, are also applicable to steam and other engines.
.
It is well known that, when a gas-engine is working at a high speed, the
fly-wheel and other parts thereof will, continue to move for a considerable period of
time after the supply of gas to the said engine has been shut off. Great incon-
venience, and, in some cases, considerable danger is caused by reason of this fact.
But by my invention the supply of gas to the engine can be shut off, and the
motion of the said fly-wheel and other parts immediately arrested; or, if desired,
the motion of the said fly-wheel and other parts can be arrested, without shutting
off the supply of gas to the engine.
My said invention consists essentially in the employment, in combination with
the fly-wheel of a gas or other engine, of a brake and means for operating the same,
and (in some cases) simultaneously operating the cock or valve, for the supply of
gas or other fluid to the said engine. I sometimes arrange my brake-apparatus in
such a manner that it can be operated from a distant point, as herein-after
explained.
·
In the accompanying drawing, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a side elevation of a gas-engine with my improvements applied
thereto.
Figure 2 is a section on the line x, x, Figure 1, and
Figure 3 is a plan shewing the brake-shoe hereinafter described.
Like letters indicate corresponding parts throughout the drawing.
A is the bed-plate, and B is the fly-wheel of the engine.

page_text: a is a bar or rod of iron or other suitable material, which is rigidly attached to
one of the flanges A¹ of the bed-plate A, and which is turned at its end a¹ to serve
as a pivot or fulcrum for the brake-shoe b. This brake-shoe consists essentially of
a curved bar b' of iron or other suitable metal lined with leather or similar
material, as shewn at b', to increase the friction between the brake-shoe and the
fly-wheel. The said brake-shoe partially surrounds the periphery of the fly-
wheel B as shewn, and the free end of the said brake-shoe is made with a
projection or lug c in which is inserted an adjustable eye-bolt d.
e is a hand-lever, which is fixed on a shaft f carried in suitable bearings in
a bracket g. firmly attached to the bed-plate A. The shaft ƒ has an arm or
extension f¹, which constitutes the short arm of the lever e and is coupled to the
eye-bolt d, so that, by moving the said lever in the direction of the arrow e
Figure 1, the brake-shoe b will be forced against the periphery of the fly-wheel B.
The lever e is arranged to slide in contact with a segment h which is rigidly
attached to the bed-plate A and is provided with a series of screw-threaded
apertures h¹ into either of which a screw-pin i can be inserted to limit the
movement of the said lever. This lever is, moreover, connected by a link j with
one end of the lever k which is pivotted at ¹ to the segment h, and is connected at
its other end by a rod to the cock for controlling the supply of gas to the
engine.
The lever e is provided with a pawl m adapted to engage with one or other of
the teeth upon the segment h to hold the said lever in the desired position
when the brake is applied. I may, however, provide other suitable means for
effecting this object, for example, a spring-bolt similar to that employed in
combination with the lever and segment of the ordinary steam-engine reversing
gear.
In order that the friction between the brake-shoe and the fly-wheel shall be
gradually increased (when the brake is applied) until it is sufficient to arrest the
motion of the said fly-wheel and other moving parts of the engine, I prefer to
make the said brake-shoe as follows, that is to say, I employ two strips 62 of
leather or similar material, which I secure at suitable intervals to the metal bar b¹
by rivets, as shewn in Figure 3, or otherwise, the attached parts of one strip
being opposite the loose parts of the other strip; and I insert pieces 6s of leather or
other suitable material between the metal bar b¹ and the strips 6 at the loose
parts of the latter, thus producing a series of raised or projecting portions of the
said strips. When the brake is applied, these raised or projecting portions come
successively in contact with the rim of the fly-wheel B; the friction between the
brake-shoe and the said fly-wheel is, therefore, gradually augmented or increased.
To provide for operating my brake-apparatus from a distant point, for example,
from any of the rooms of a factory or other building in which the engine is
employed, I prefer to fix on the shaft fa weighted lever n and to employ a hook
or catch o which is pivotted to the segment h and is adapted to engage with a pin
or stud p projecting from the lever e, and thus hold the brake-shoe b away from
the fly-wheel. This hook or catch is arranged to be disengaged from the said pin
or stud, when necessary, by means of a wire or cord, which is conducted to the
different rooms of the factory or other building, and is connected in each room with
a lever or other suitable device for operating it. When the said hook or catch is
thus disengaged from the pin or stud p, the weighted lever n falls by gravity and
simultaneously closes the gas-cock and applies the brake to the fly-wheel. It is
obvious that, if desired, I might employ other suitable means for operating the said
brake-apparatus from a distant point.
Although I have shown and described my brake-apparatus as arranged to be
operated simultaneously with the supply cock for the gas or other fluid, it may, if
desired, be arranged independently thereof as will be readily understood.

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Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
'I claim is;-
First. The employment, in combination with the fly-wheel of a gas or other
'engine, of a brake and means for operating the same either simultaneously with
the cock or valve for the supply of gas or other fluid to the engine or independently
thereof, substantially as set forth.
Second. The arrangement of my brake-apparatus in such a manner that it can
be operated from a distant point, substantially as set forth.
HASELTINE, LAKE & Co.,
For the Applicant.