the Speed of Tramway, Locomotive, Road, and other Engines.
Year: 1885

page_text: the Speed of Tramway, Locomotive, Road, and other Engines.
I, RICHARD CLERE PARSONS, of Airedale Foundry, Leeds in the County of York,
Engineer, do hereby declare the nature of my invention for "IMPROVED MODE of
AND APPARATUS FOR AUTOMATICALLY CONTROLLING THE SPEED OF TRAMWAY,
LOCOMOTIVE, ROAD, AND OTHER ENGINES" to be as follows:-
This invention has for its object to automatically control the speed of Tramway,
Locomotive, Road and other engines by means of a pump which receives its motion
from the driving gear or the axle and which forces oil or other liquid against a
loaded plunger or piston in a cylinder. The plunger rod is, connected to the
spindle of a valve which admits steam or other fluid to a cylinder which actuates
the brake.
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The action of the apparatus is as follows:-If the speed of the engine is below.
that for which the apparatus has been adjusted, the liquid from the pump
discharged through an adjustable "by-pass" hole in the discharge passage and
flows into the suction well, where it is again drawn into the pump. But if the
speed exceeds that for which the apparatus is adjusted, the "by-pass" is insufficient
to carry away the amount of liquid pumped; the pressure in the pump then
increases and the loaded plunger connected to the steam or other brake valve is
moved. Steam or other fluid is thus admitted to the brake cylinder and the brakes
are applied to the wheels.
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The pressure is maintained on the brakes until the speed is so reduced that the
amount of liquid pumped can again all flow through the "by-pass;" the loaded
plunger then returns, the brake valve is moved back and the brakes are relieved.
The apparatus is made of such proportions that several strokes of the pump
plunger may be made before the loaded plunger is moved.
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A regulator valve is also fixed in the pump to permit only a certain velocity of
flow of the liquid, so that in the case of locomotive engines, any sudden acceleration
caused by the wheels "skidding" on the rails, cannot produce a corresponding
discharge of liquid to the loaded piston. By these, means the brake is not thrown
on when the wheels "skid."
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page_text: For fixed engines and marine engines the loaded plunger is inade to actuate the
throttle valve or the slide valve, and thus to vary the amount of working fluid
admitted to the cylinder. In this case the apparatus is made as sensitive as
possible to prevent "racing."
In either case the loaded plunger may be made to apply the brake or move the
throttle valve direct, or it may be made to actuate a valve in connection with a
cylinder which will do the required work.
the Speed of Tramway, Locomotive, Road, and other Engines.
I, RICHARD CLERE PARSONS of Airedale Foundry, Leeds in the County of York,
Engineer, 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 for its object to automatically control the speed of Tramway,
Locomotive, Road and other engines by means of a pump which receives its motion
from the driving gear or the axle and which forces oil or other liquid against a
loaded plunger or piston in a cylinder. The plunger rod is connected to the
spindle of a valve which admits steam or other fluid to a cylinder which actuates
the brake.
The action of the apparatus is as follows:-If the speed of the engine is below
that for which the apparatus has been adjusted, the liquid from the pump is
discharged through an adjustable "by-pass" hole in the discharge passage and
flows into the suction well where it is again drawn into the pump. But if the
speed exceeds that for which the apparatus is adjusted; the "by-pass" is insufficient
to carry away the amount of liquid pumped, the pressure in the pump then
increases and the loaded plunger connected to the steam or other brake valve is
moved. Steam or other fluid is thus admitted to the brake cylinder and the brakes
are applied to the wheels.
The pressure is maintained on the brakes until the speed is so reduced that the
amount of liquid pumped can again all flow through the "by-pass;" the loaded
plunger then returns, the brake valve is moved back and the brakes are relieved.

page_text: The apparatus is made of such proportions that several strokes of the pump
plunger may be made before the loaded plunger is moved.
A regulator valve may be fixed in the suction passage to the pump to permit
only a certain inflow of the liquid so that in the case of locomotive engines, any
sudden acceleration caused by the wheels slipping on the rails, cannot produce a
corresponding discharge of liquid to the loaded piston. By these means the brake
is not thrown.on when the wheels slip.
For fixed engines and marine engines the loaded plunger is made to actuate the
throttle valve or the slide valve, and thus to vary the amount of working fluid
admitted to the cylinder. In this case the apparatus is made as sensitive as
possible to prevent racing.
In either case, the loaded plunger may be made to apply the brake or move the
throttle valve direct, or it may be made to actuate a valve in connection with a
cylinder, which will do the required work.
The accompanying drawing is a vertical section shewing apparatus according to
my invention as applied to a tramway locomotive.
A is the pump which may be single acting as shewn or may be double-acting.
It is driven by any suitable part of the engine and supplied with liquid from a
well B. C is the suction valve and D the delivery valve. E is a pipe from the
delivery valve to a cylinder G fitted with a piston F that is loaded with a spring.
The piston rod H is connected to a slide valve J by which fluid under pressure can
be admitted from the supply pipe I to the passage K leading to the brake cylinder
to put on the brakes, or can pass from the brake cylinder to the discharge pipe Q
for the release of the brakes.
The brake valve J can also be moved by hand by means of a lever L and
rod M M that can be worked from either end of the engine. In the rod H
I provide a slot for the pin of the lever L so that the driver cannot by moving this
lever prevent the automatic brake from acting if he wishes the proper speed to be
exceeded.
N is a pipe for carrying back to the well B any liquid that may leak past the
piston F. The walls of the valve box in which the suction and delivery valves C
and D are situated have small holes through them but by preference I make these
holes through the valves themselves, the hole through C being adjustable by
screwing in or out a conical plug P. As liquid passes through these holes in
each direction at every stroke of the pump, the small holes are kept clear of
obstructions.
When the speed of the engine and consequently of the pump increases, as only
a little fluid can return through the holes of the valves the pressure in the delivery
pipe E increases, and this acting on the piston F moves it by degrees in opposition
to the spring.
When the maximum speed for which the apparatus is adjusted is reached, the
slide valve J uncovering the port of K admits steam from the boiler, or other fluid
under pressure, supplied by the pipe I to the brake cylinder whereby the brakes
are applied and the engine is stopped. The liquid acting on the piston F then
gradually escapes through the holes in the valves D and C, the spring in the
cylinder G moves back the piston F and the slide J putting the brake cylinder in
communication with the exhaust passage Q, and the brake is released.
The piston For the piston of the brake cylinder may be connected to the
throttle or other regulating valve of the engine so as to shut off steam at the same
time that the brakes are put on.
The apparatus may be adjusted to apply the brakes, when the desired speed is
reached, by means of the screw plug P. The limit of speed may also be altered by
means of the screw S lengthening or shortening the rod of the slide valve so as to
admit steam sooner or later to the brake cylinder. Both these regulating screws
may be covered or locked so as to be out of the driver's control.

page_text: 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 :-
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1. The herein described method of automatically controlling the speed of
Tramway, Locomotive, Road and other engines, by means of a pump worked by
the engine which causes adjustable pressure of liquid to act on a piston connected
to a valve that governs the supply and discharge of a brake cylinder.
2. The construction, substantially as berein described and illustrated by the
drawing, of apparatus for automatically controlling the speed of Tramway and
other engines.