Patent ID: 8011483

Claim:
A ventilation device for a combined spring accumulator and operating brake cylinder, comprising: a spring-actuated brake cylinder including a first piston actuatable by a first spring, said first piston dividing said spring-actuated brake cylinder into a first pressurized-fluid chamber and a first spring chamber housing said first spring; an operating brake cylinder including a second piston actuatable by a pressurized fluid against a force of a second spring, said second piston dividing said operating brake cylinder into a second pressurized-fluid chamber and a second spring chamber housing said second spring; a piston rod on said first piston of said spring-actuated brake cylinder, said piston rod extending in the direction of said second pressurized-fluid chamber of said operating brake cylinder via a first through hole in a first wall separating said first pressurized-fluid chamber of said spring-actuated brake cylinder from said second pressurized-fluid chamber of said operating brake cylinder, said piston rod being guided sealingly in said first through hole by means of a sealing element annularly surrounding said piston rod; a valve disposed at least one of in and on said piston rod of said first piston of said spring-actuated brake cylinder, said valve being operable to effect ventilation of said first spring chamber of said spring-actuated brake cylinder from said second pressurized-fluid chamber of said operating brake cylinder during depressurization of said second pressurized-fluid chamber, said valve including a first working port, a second working port, a working chamber, a control chamber in communication with said second pressurized-fluid chamber of said operating brake cylinder, and a movable valve piston, said valve being movable against a restoring force from an open position to a closed position during injection of pressurized fluid into said second pressurized-fluid chamber of said operating brake cylinder, said movable valve piston of said valve being drivable against a restoring force in closing direction of said valve when a pressure of said valve piston injected into said second pressurized-fluid chamber of said operating brake cylinder is admitted into said control chamber; a space defined at an end of said movable valve piston of said valve distal to said control chamber and bounded by said movable valve piston, said space being in communication with said second working port; and said movable valve piston including at least one passage via which said first working port communicates with said space in said open position of said valve, said at least one passage connecting said first working port with said second working port, and being formed by (i) a recess in said valve piston extending from an end face of said valve piston distal to said control chamber into said valve piston, and (ii) at least a second through hole penetrating through a second wall of said valve piston bounding said recess and in communication with said recess.