GB561159A - Improvements in or relating to fluid-operated clutch and like mechanisms - Google Patents

Abstract

561,159. Clutch actuating mechanism. ABBEY, A. (Bliss Co., E. W.) Nov. 3, 1942, No. 15490. [Class 80 (ii)] [Also in Group XXIX] In a fluid-pressure system for actuating a clutch and brake mechanism, the fluid pressure is built up in two stages, the first stage by an electric motor which stalls at a predetermined fluid pressure and is then held in that' position by an electric brake, and the second stage by the driven machine. A driven shaft 20 is clutched by friction plates 28, 30, 47, to a driving pulley 22 when fluid pressure is built up in cylinders 35, and is frictionally connected to a fixed brake member 55 when the fluid pressure in the cylinders 35 is reduced. A combined electric motor and brake 60, 62, of known type is connected by gearing 65, 66, to a shaft 67 having a cam 71 co-operating with a plunger 73 in a cylinder 74 connected by piping 80, 82, to the clutch cylinders 35. A cam 87 on a shaft 85 geared to the driven shaft-20 co-operates with a follower roller 88 on a two-part piston 90, 91. The two parts of the piston 90, 91, are interconnected by a bolt 92 and are pressed apart by a compression spring 95, the small end 96 of the part 91 working in a cylinder 97 connected by piping 98 to the pipe line 82. The electric motor 60 and brake 62 are wired to a threephase source of power as shown in Fig. 5. Forward and reverse switches 117, 118, have relays 117<1>, 118<1>. Switches 125, 125<1>, which may be controlled by the cam 87 are included to give automatic declutching. In operation, depression of a switch 120 energizes relay 117<1> to close switch 117 and energize motor 60 and release brake 62. Motor 62 rotates cam 71 to depress plunger 73 and produce fluid pressure in the piping 80, 82. When a predetermined fluid pressure, sufficient to give initial clutch engagement, is attained, the motor 60 stalls, the switch 120 is then released, and the brake 62 holds the motor in the clutch engaged position. Rotation of the cam 87 thereupon operates the piston 90, 91, to increase the fluid pressure in the pipe 82 to giye full clutch engagement. The spring 95 is calibrated to yield above a predetermined maximum fluid pressure. When the driven machine has made its working stroke the cam 87 opens switch 125 and closes switch 125<1>, thus throwing in the reversing switch 118, whereupon the motor 60 reverses and the plunger 73 moves upwardly and lowers the fluid pressure in the clutch cylinders 35 to cause clutch disengagement. If a, line switch 127 is open continuous clutch engagement results. Release of the clutch may also be effected by closing a switch 121.