PNEUMATIC SERVOMOTOR Russian patent published in 1996 - IPC

FIELD: transport; automobile braking systems. SUBSTANCE: pneumatic servomotor has housing divided by piston into front and rear chambers. Front chamber communicates with vacuum source. Rear chamber accommodates distributing device with ring valve spring-loaded relative to control rod hinge-connected with plunger. The latter is installed for translational motion and engagement with thrust disc in piston step bore coupled through normally open ring seat made on end face of piston with front chamber, and through normally closed ring seat made on end face of plunger, with atmosphere. Piston stepped bore is connected also with rear chamber through radial slot accommodating with clearance a flat plunger travel stop spring-loaded at one side and installed by one end on support in piston and by other end, between two projections of plunger. Servomotor has additional distributing device for accelerated additional communication of rear chamber with atmosphere. Valve of distributing device is arranged on plunger travel stop. Normally closed seat is made on surface of piston radial slot and is connected with atmosphere through additional longitudinal channel. EFFECT: enhanced reliability of brake. 4 cl, 1 dwg