Patent GB-950685-A (GB)
Title: Improvements in governors
IPC: G05D13/10
Filed: 1961-11-28
Abstract: 950,685. Governors. GES FUR LINDE'S MASCHINEN A. G. Nov. 28, 1961 [Nov. 29, 1960], No.42488/61. Heading G3B. A centrifugal governor comprises a rotatable shaft 1, driven by an engine the speed of which is to be controlled, along which shaft is displaceable in response to the centrigugal force experienced by the governor, a member 6, which automatically controls the predetermined speed of the engine, means e.g. a spring 16 opposing the displacement of the member 6 corresponding to an increase in engine speed, a control lever 20 which varies the load of the spring 16 on the member 6 and thus predetermines the engine speed, and means to assist the actuation of the lever 20 when actuated to increase the load on the member 6, the assisting means operating automatically in response to the engine speed. A disc 2 solid with the shaft 1 carries cranked levers 4 with weights 5. The member 6 is moved as the weights move radially outwards and this movement is transmitted through levers 9, 10 to an arm 14 controlling a fuel supply arrangement 15. The lever 20 is pivoted at 21 and has a slide block 19 engaging with a groove 18 in the second member 17. The arm 20 enables the second member 17 to be adjusted to adjust the force exerted by the spring 16 on the member 6 and thus setting the governor. A chamber 37 is fixed to the second member 17, and a second chamber 40 is slidably mounted on the shaft 1 and holds the faces 47, 46 of the chambers 39, 40, respectively apart. The auxiliary force is applied to the chamber 40 and in Fig. 1 this force is derived from an air blower (not shown) driven by the engine and applying pressure in proportion to the speed of rotation of the engine to a cavity 31, with a diaphragm 29. The diaphragm will bulge under the applied pressure and the movement of the centre of the diaphragm is transmitted via members 27, 25, 22 to the chamber 40. At low engine speeds the auxiliary force is taken up in compressing a spring 38, but when the forces 46, 47 contact each other any increase in the auxiliary force will be applied to the second member 17. Thus the auxiliary force is applied only at higher engine speeds when the centrifugal force on the weights 5 is tending to increase rapidly. The auxiliary force serves to reduce the effort required to move the second member 17 by means of the lever 20. The auxiliary force may alternatively be derived from a blower adapted to charge or purge the cylinders of an engine, as from a suction unit or an exhaust pipe associated with the engine. Also, the diaphragm may be subjected to suction pressure from the suction unit on one side and to the exhaust pressure on the other side, or two diaphragms may be used each connected to a different one of the pressure sources referred to above. As a further alternative the auxiliary force may be derived from centrifugally acting weights pivotally mounted on the shaft 1 and adopted to move the chamber 40 in the same way that the member 6 is moved by the levers 4. The levers and weights providing the auxiliary force are preferably smaller than the levers and weights 4, 5 respectively, but even if they are the same size the auxiliary force will not exceed that on the member 6 due to the presence of the spring 38.