Combination brake warning switch and proportioning valve

Abstract

Abstract D R A W I N G A COMBINATION BRAKE WARNING SWITCH AND PROPORTIONAL VALVE INCLUDES A HOUSING HAVING AN AXIAL BORE WITHIN WHICH IS LOCATED A SWITCH PISTON AND A PROPORTIONING PISTON AT OPPOSITE ENDS OF THE BORE. FLUID FROM TWO CIRCUITS OF A DUAL BRAKE SYSTEM MASTER CYLINDER IS INTRODUCED TO THE BORE ON OPPOSITE SIDES OF THE SWITCH PISTON WHICH PERFORMS A SWITCH ACTUATING FUNCTION IN CASE OF A PRESSURE UNBALANCE. THE PROPORTIONING VALVE PISTON COOPERATES WITH A VALVE SEAT MEMBER SLIDABLY CARRIED ON THE END OF THE SWITCH PISTON TO REDUCE THE OUTLET PRESSURE IN ONE CIRCUIT WHEN THE INLET PRESSURE EXCEEDS A PREDETERMINED LEVEL. IN THE EVENT OF FAILURE OF THE OTHER CIRCUIT, MOVEMENT OF THE SWITCH PISTON MOVES THE VALVE SEAT MEMBER AWAY FROM THE PROPORTIONING PISTON WHICH IS THEN INOPEARABLE. WHEN THE PROPORTIONING VALVE IS OPERATIVE, THE MOVABLE VALVE SEAT MEMBER COOPERATES WITH THE PROPORTIONING PISTON SO THAT THE PROPORTIONAL RELATION BETWEEN INLET AND OUTLET PRESSURES IN THE ONE CIRCUIT IS MAINTAINED WHEN THE PRESSURES ARE DECREASING. A STOP IS PROVIDED TO PREVENT THE VALVE SEAT MEMBER FROM ENGAGING IN PROPORTIONING PISTON IN THE EVENT OF A PRESSURE LOSS IN THE ONE CIRCUIT.

Inventors

• 👤 Frederick D Keady
• 👤 Ellis M Wellman

Bibliographic Details