GB1089208A - Pneumatic actuators of the piston type - Google Patents

Abstract

1,089,208. Pneumatic single-stroke apparatus. V. MAJONE. May 16, 1966 [May 17, 1965], No.21690/66. Heading F1P. Stepwise linear displacement of a compressed air actuated piston 2, Fig. 1 is effected by selective abutment of a succession of axially spaced discs 11 projecting radially from the piston rod 3 against one or other of a pair of oppositely facing abutment blocks 15, 16 carried by a frame 14 secured round the cylinder wall and connected together for simultaneously reciprocation transversely to the rod 3. Block 16 is biased by tension springs 21, 22 to its retracted position whereas block 15 is biased by compression springs 27, 27' to its extended position. On application of air pressure through a line 45 to beneath a piston 25 block 16 is extended radially inwardly and this movement is transmitted by rods 33, 34 Fig. 2, to block 15 which is thereby retracted. To retract block 15 whilst allowing block 16 to remain retracted air pressure is admitted through a line 46 to lift a piston 32 which is tied by a cross-head 70 and rods 27, 28 to said block 15. Air supply is controlled by solenoid valves 51, 52, 53 Fig. 4, in the line 44 leading to the working cylinder space 1' and in lines 45, 46 respectively and said valves are energized by remote cam actuated switches 55 to 57. The various step movements of the piston are transmitted to a lever 37 for controlling means such as the injection pump of a diesel engine through a flexible tape 7 secured at one end to the head 4 of rod 3 and at the other end to a spring drum 8 carrying a cam 38 and a follower 36 secured to the lever 37. Rapid return of piston 2 from any position is effected by the drum spring 9 acting through the tape 7 when both blocks 15, 16 are in their retracted position.