PNEUMATIC SERVOMOTOR Russian patent published in 1995 - IPC

FIELD: automotive transport; pneumatic servomotors. SUBSTANCE: servomotor has housing 10 accommodating piston 20 with rear tubular part 22 and movable wall 12 which limits front chamber 16 constantly connected with vacuum source, and rear chamber 18 selectively connected either with front chamber 16 or with atmosphere through valve (20a, 32a, 40) set into operation by control rod 34 which can thrust through plunger 32 against one of sides of reaction disk 58 made integral with piston rod 56. Valve 40 carries shutoff member engaging by active part with first seat 20a of valve formed on piston 20. Means 62 are provided at valve input to direct air. EFFECT: enhanced reliability of operation. 6 cl, 1 dwg