Patent GB-606669-A (GB)
Title: Improvements in and relating to a governor for controlling the speed of an internal combustion engine
IPC: F02D9/00
Filed: 1945-06-07
Abstract: 606,669. Fluid-pressure servomotors. MALLORY, M. June 7, 1945, No. 14346. [Class 135] [Also in Group XXVII] A device for controlling the speed of an internal-combustion engine comprises a suction servomotor which is operatively connected to a throttle valve in the air intake of the engine so that application of suction from the air intake to the servomotor can move the throttle towards its closed position and the suction servomotor has an air bleed connection which when fully open renders the servomotor inoperative, and the air bleed connection is controlled by means of a valve assembly including a centrifugally operated element presenting a valve surface, which is rotated in fixed relation to engine speed and is displaceable away from the closed position with decrease of engine speed to control the air bleed connection and thus govern the operation of the throttle valve. As shown, a centrifugal valve 33 is mounted in a cylinder 37 enclosed in the ignition distributer housing 31 and rotated with the distributer shaft 25. The valve 33 at a predetermined speed closes a port 38 leading to the atmosphere. The port establishes communication between the atmosphere and a conduit 13 by passages 39, 34, 36, 30. The conduit 13 leads to a suction-operated device comprising a diaphragm 11 in a chamber 12. The conduit 13 also communicates with orifices 15, 17 in venturies 53, 18, one on each side of an unbalanced valve 4 in the engine induction passage on the engine side of the carburetter. Suction from the induction passage passes to the chamber 12 by conduits 14, 16 and 13, but the effect of this suction is destroyed by the pressure of the atmospheric air entering through port 38. When the centrifugal valve 33 closes the port the suction devices becomes operative and diaphragm 11 which is interconnected with the valve 4 moves this valve towards the closed position and restricts the passage of combustible mixture to the engine. It is stated that the opening and closing of the valve 33 varies with the speed and vacuum in the line 13 and that the opening and closing of the valve 4 follows the engine load very closely to maintain a predetermined governed speed. When the valve 4 moves towards closed position the suction at 17 becomes increased, but the effect of this on the diaphragm is counteracted by a bleed into the chamber 12 through the orifice 15. The flow in the induction passage tends to open the unbalanced valve and act in opposition to the suction-operated device and this prevents the valve shutting too quickly. Suction acting on the valve 33 has a similar effect. An adjustable screw 19 controls the magnitude of the effect of the suction on the diaphragm. The tension of the spring 40 controlling the valve 33 can be suitable for governing a fuel injection engine, in which case the air supply is controlled by the valve 4. The throttle valve 4 may either be solely under automatic control of the centrifugally-operated governor valve or alternatively a master control by a throttle pedal or lever may be provided connected to a crank 6 of the valve with lost motion.