Master cylinder for variable actuation of hydraulic equipment - has two coaxial piston springs in series and distance piece acting as piston stop

摘要

Master cylinder for equipment, e.g. for buses and lorries with air brake system and accessory equipment such as doors, comprises a piston (4) on which one face is subjected to compressed air, while a spring disposed in the cylinder abuts against the other face. The spring consists of two coaxial springs (6, 9) arranged in series by an intermediate member (7) which pref. acts as a stop for the piston. Pref. the clearance of the springs between the intermediate member and the i.d. of the outer spring (9), and between intermediate member and o.d. of the inner spring, (6), is as narrow as possible to allow axial displacement without oscillation or buckling. The cylinder has smaller dimensions for a given power.