SERVO-OPERATED BRAKE WITH REDUCED WORKING STROKE Russian patent published in 2000 - IPC

FIELD: transport engineering; brake systems with air boosters. SUBSTANCE: invention relates to systems with vacuum boosters made integral with brake master cylinders. Control rod 28 controls opening of booster valve to set into operation main hydraulic piston of brake master cylinder 200. Main hydraulic piston has hollow movable cylinder 38. Secondary hydraulic piston 40 slides inside hollow movable cylinder 38. Movable partition of booster has rigid skirt 20. Partition is rigidly coupled with hollow movable cylinder 38 and it slides on pneumatic piston 22 forward through axial distance L. If stroke of main hydraulic piston is less than axial distance L, ring piston 70 is rigidly coupled with piston, and when stroke exceeds axial distance L, ring piston slides relative to main hydraulic piston. EFFECT: provision of small free travel of brake pedal, reduced axial length of device. 9 cl, 4 dwg