Hydraulisches Ventil, insbesondere zum Lüften einer Federspeicherbremse

摘要

The invention concerns a hydraulic valve used in particular to ease a spring-loaded brake and which has a housing (10) and an actuator element (40) mounted on the housing and adjustable in two opposite directions. The valve also has an obturator element (14) fitted so that it can move within the housing, a control spring (26) fitted between a mobile support element (27) and the obturator element and a reset spring (25) fitted between the housing and a support element (28). The force in the reset spring can be increased by moving the actuator element in one direction and, when the actuator element moves back in the opposite direction, the reset spring moves the control-spring support element in the direction which increases the force in the control spring. In order to keep the force necessary to operate the brakes low, mechanical force-magnification means (48, 51) are fitted to act between the reset and control springs. The resetting force which the reset spring is required to produce is thus relatively small, thus also making it possible to keep the force necessary to compress the reset spring small.