Engine Equipment
after the engine stops so the air shut-off valve can be
Emergency Stop Knob
opened for restarting after the malfunction has been
In an emergency, or if after pulling the engine stop
corrected.
knob the engine continues to operate, the emergency
stop knob may be pulled to stop the engine. The
emergency stop knob, when pulled, will trip the air
Throttle Control
shut-off valve located between the air inlet housing
and the blower and shut off the air supply to the
The engine throttle is connected to the governor speed
engine. Lack of air will prevent further combustion of
control shaft through linkage. Movement of the speed
the fuel and stop the engine.
control shaft changes the speed setting of the governor
The emergency stop knob must be pushed back in
and thus the engine speed.
ENGINE PROTECTIVE SYSTEMS
MANUAL SHUTDOWN SYSTEM
A manually-operated emergency engine shutdown
device, mounted in the air shutdown housing, enables
the engine operator to stop the engine in the event an
abnormal condition should arise. If the engine
continues to run after the engine throttle is placed in
the no fuel position, or if combustible liquids or gases
are accidentally introduced into the combustion
chamber causing overspeeding of the engine, the
shutdown device will prevent damage to the engine by
cutting off the air supply and thus stopping the engine.
The device consists of a shutdown valve mounted in
the air shutdown housing and a suitable operating
mechanism (Fig. 2).
The air shut-off valve is retained in the open position
by a latch. A wire or cable assembly is used to trip the
latch. Pulling the emergency shutdown knob all the
way out will stop the engine. After the engine stops,
the operator must push the emergency shutdown knob
Fig. 2 - Manually Operated Emergency Engine
all the way in and manually reset the air shut-off valve
Shutdown Valve Mounting
before the engine is started again.
AUTOMATIC MECHANICAL SHUTDOWN SYSTEM
The automatic mechanical shutdown system (Fig. 3) is
through the adaptor and passes over the power
designed to stop the engine if there is a loss of oil
element of the valve. Engine oil, under pressure, is
pressure, loss of engine coolant, overheating of the
directed through a restricted fitting to the tempera-
engine coolant, or overspeeding of the engine. Engine
ture-sensing valve and to an oil pressure actuated
oil pressure is utilized to activate the components of
bellows located on the air inlet housing.
the system.
The pressure of the oil entering the bellows overcomes
A coolant temperature-sensing valve and an adaptor
the tension of the bellows spring and permits the latch
and copper plug assembly are mounted on the exhaust
to retain the air shut-off valve in the open position. If
manifold outlet. The power element of the tempera-
the oil pressure drops below a predetermined value,
ture-sensing valve is placed against one end of the
the spring in the bellows will release the latch and
copper plug. and the other end of the plug extends
permit the air shut-off valve to close and thus stop the
into the exhaust manifold. Engine coolant is directed
engine.
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