0349060 JOHNSON COVER, Trunnion

SAFETY SHUTOFF CONTROL
1. Safety shutoff control. 2. Plug (pressure oil connection to water temperature shutoff). 3. Fuel rack shutoff. 4. Pressure oil line to shutoff control. 5. Reset button. 6. Emergency manual shutoff button.The overspeed shutoff portion of the control stops the engine mechanically in the event of engine overspeeding.Controls equipped with reversal protection are activated by low oil pressure in the event the engine runs in reverse.The emergency manual shutoff button (6) works in conjunction with the overspeed shutoff and provides the operator with an emergency shutoff.Reset button (5) is used to reset the control after the engine has been stopped by the control because of low oil pressure or high water temperature. It is not necessary to reset the control after a normal engine stopping.The shutoff mechanisms receive lubricating oil from leakage past the oil pressure shutoff piston. An internal drain is provided by two drilled holes in the bottom of the housing.Operation
Low Oil Pressure Shutoff and Water Temperature Shutoff
The oil pressure control will stop the engine should the lubricating oil pressure drop below the safe operating range, or when excessively hot water opens a shutoff control valve which simulates low oil pressure.Under normal engine operating conditions, engine lubricating oil is directed through supply line (4), see previous illustration, to cover (4). This oil is then directed against control piston (6).One end of worm slide follower (2) is piloted into guide (5). The follower is free to pivot about slide follower shaft (3) in the housing and is actuated by the movement of guide (5).
SHUTOFF CONTROL (Cross Sectional Side View; Normal Operation)
1. Worm shaft. 2. Slide follower. 3. Slide follower shaft. 4. Cover. 5. Guide. 6. Piston. 7. Spring. 8. Release rod.Worm shaft (1) is driven by the safety shutoff drive which is driven by the fuel pump and governor drive shaft thus rotating any time the engine is operating.When the engine oil pressure is within the safe operating range, the piston (6) is held against the guide (5) compressing the spring (7) and pivoting the slide follower (2) out of mesh with the worm shaft (1).Should the lubricating oil pressure drop below normal operating range, the oil pressure acting on piston (6) will also drop and spring (7) will force guide (5) and piston (6) to the stop position and cause slide follower (2) to pivot on shaft (3) and mesh with worm shaft (1).
SHUTOFF CONTROL (Top View; Normal Operation Position)
1. Worm shaft. 2. Slide follower. 3. Slide follower shaft. 5. Guide. 8. Release rod. 9. Pin. 10. Release lever. 11. Spring.With slide follower (2) engaged with worm shaft (1), the slide follower will travel the length of worm portion of shaft (1). As the follower comes close to the end of its travel, pin (9) on the follower makes contact with release lever (10). The release lever is then tripped and releases rod (8) which is forced outward by spring (11).
SHUTOFF CONTROL (Side View; Shutoff Operation Position)
1. Worm shaft. 2. Slide follower. 3. Slide follower shaft. 5. Guide. 6. Piston. 7. Spring. 8. Release rod.Release rod (8) moves to contact spring-loaded plunger (12) in the rear of the governor drive housing. The plunger then moves forward contacting the lever assembly in the governor drive housing, moving it to the OFF position and stopping the engine.
SHUTOFF CONTROL (Top View; Shutoff Operation Position)
1. Worm shaft. 2. Slide follower. 8. Release rod. 9. Pin. 10. Release lever. 11. Spring.
RACK SHUTOFF
12. Plunger.Overspeed Shutoff
Should an overspeeding condition occur, the overspeed shutoff control located in the shutoff control housing will actuate the release rod and then the fuel rack to OFF position to stop the engine.Overspeed carrier assembly (1) is driven by gears and the safety shutoff drive which is driven by the fuel pump and governor drive shaft thus rotating whenever the the engine is operating. Within the carrier flange is a rotating weight (2) held toward the center of the carrier shaft by an adjusting screw, spring and nut.
OVERSPEED CONTROL
1. Carrier assembly. 2. Rotating weight. 3. Release lever. 4. Release rod.As the engine rpm increases, the centrifugal force acting on the weight increases and the weight moves out of the carrier flange. This movement of the weight continues until the spring force (tending to hold the weight in) is equal to the centrifugal force (tending to throw the weight out).When the engine overspeeds, the weight will continue to move out of the carrier flange until it makes contact with release lever (3) and releases release rod (4) which actuates the fuel shutoff linkage and stops the engine.Emergency Manual Shutoff Button
The emergency shutoff button (5) is never used for normal shut-down. Under normal conditions all load would be first removed from the engine and the engine rpm lowered to low idle before the engine is shut off.If an emergency situation is encountered where the engine should be shut down immediately, push the emergency shutoff button and hold in the button until the release rod has been released.By pushing button (5), plunger (4) acts against pin (3) which forces spring-loaded weight (1) out of carrier assembly (2) creating the same condition as overspeeding.
EMERGENCY SHUTOFF
1. Weight. 2. Carrier assembly. 3. Pin. 4. Plunger. 5. Button.Resetting The Control
Whenever the engine has been shut down by the safety shutoff control, the reason for the shutdown must be corrected and the control reset before the engine can be restarted.Resetting After Overspeed and Emergency Manual Shut-down
The spring-loaded release rod is relatched by moving the reset lever (1). The engine can now be started.
SHUTOFF CONTROL RESET
1. Lever.Resetting After Low Oil Pressure or Water Temperature Shut-down
Push reset button (4) on the top of the shutoff control housing. This manually moves the control piston (3) and pin against slide follower guide (1). The movement of the guide pivots worm slide follower (2) away from the end of the worm shaft and allows the spring to return the slide follower to the start of the worm shaft threads.
SHUTOFF CONTROL RESET
1. Slide follower guide. 2. Slide follower. 3. Piston. 4.