Patent GB-690850-A (GB)
Title: Improvements in internal combustion engine fuel control mechanisms
IPC: F02D1/00
Filed: 1951-06-04
Abstract: 690,850. Centrifugal governors. GENERAL MOTORS CORPORATION. June 4, 1951 [June 17, 1950], No. 13154/51. Class 57 [Also in Group XXVII] A fuel control device, particularly for a fuel injection pump, comprises a manually operable lever 111 for operating the fuel control linkage 85 through a floating lever 83 which is associated with a fixed cam 99 and is movable relative thereto by a speed-responsive mechanism, the fuel supply being initially set by the lever 111 and modified by the speed-responsive mechanism such that for speeds from idling to maximum, an increase of engine speed above the set speed due to decreased load effects a decrease in fuel supply, and a decrease in engine speed due to increased load also effects a decrease in fuel supply. The speed-responsive mechanism comprises a centrifugal governor 11 having low-speed and high-speed weights 13, 15, which actuate a sleeve 55, loaded by idling, intermediate, and high-speed springs 45, 35, 25, to rotate a lever 75 connected to a lever 79 carrying a pin 81 on which the lever 83 is pivoted. A pin 113 on the lever 83 is urged by a spring 115 towards an abutment 114 on a lever 109 actuated by the manual lever 111, a pin 121 at the end of lever 109 moving in a notch in a spring-loaded detent plate 125, the ends 123, 129 of which define the idling and maximum torque positions of the lever 111. When the lever 111 is rotated to move the lever 109 from the idling position towards maximum delivery the pin 113 at first follows the abutment 114 and lever 83 is rotated anticlockwise about the pivot 81 to increase the fuel supply until a roller 93 thereon contacts the cam 99, when further rotation is prevented and lost motion occurs between the abutment 114 and pin 113. The initial increase of fuel causes an increase of engine speed and the governor 11 rotates lever 79 clockwise, whereby the pivot 81 and the lever 83 move upwards, Fig. 2, and the roller 93 moves along the cam 99 and the fuel supply is further increased. Hence fuel and engine speed:; are increased in a controlled manner until the pin 113 reaches the abutment 114, when any further increase in engine speed causes clockwise rotation of the lever 83 about the pin 113 and the fuel is reduced to maintain the speed at the value set by the lever 109. At any set position of lever 109, an increase in load will cause a reduction in engine speed, whereupon the governor 11 rotates lever 79 anticlockwise and the pin 81 is moved downwards to move the roller 93 along the cam 99 and the fuel supply is reduced to prevent overloading; similarly on an increase in engine speed due to a decrease in load the pin 81 is moved upwards and the lever 83 is rotated about the pin 113, which is in .contact with the abutment 114, to increase the fuel supply. The high-speed spring 25 acts upon a flanged sleeve 31 from which projects a second flanged sleeve 39 loaded by the intermediate spring 35. The abutment 49 of the idle spring 45 is seated on an adjustable rod 47 screwed into the end of the sleeve 31. The governor weights 13, 15, have stops 131, 151 limiting their outward movement, and when the engine is stopped the idling spring 45 moves the high-speed weights to contact stop 61 on the low-speed weights 13 and urge the stops into contact with the governor sleeve 55.