Continual quick service valve device

Claim 1

A QUICK SERVICE VALVE DEVICE FOR A RAILWAY VEHICLE BRAKE SYSTEM OPERATIVE IN RESPONSE TO VARIATIONS IN PRESSURE IN A NORMALLY CHARGED BRAKE PIPE, SAID QUICK SERVICE VALVE DEVICE COMPRISING: (A) A CASING HAVING FORMED THEREIN A QUICK SERVICE CHAMBER, (B) A MOVABLE ABUTMENT SUPPORTED BY SAID CASING AND SUBJECT ON ONE SIDE TO PRESSURE IN THE BRAKE PIPE AND ON THE OPPOSITE SIDE OF PRESSURE IN THE QUICK SERVICE CHAMBER, (C) FIRST VALVE MEANS OPERATIVE UPON MOVEMENT OF SAID MOVABLE ABUTMENT IN ONE DIRECTION RESPONSIVELY TO A REDUCTION IN PRESSURE IN THE BRAKE PIPE TO EFFECT VENTING OF FLUID UNDER PRESSURE FROM SAID ONE SIDE OF SAID MOVABLE ABUTMENT AND FROM THE BRAKE PIPE TO ATMOSPHERE, (D) SECOND VALVE MEANS AND (E) MEANS PROVIDING A LOST MOTION CONNECTION BETWEEN SAID MOVABLE ABUTMENT AND SAID SECOND VALVE MEANS TO RENDER SAID SECOND VALVE MEANS OPERATIVE BY SAID MOVABLE ABUTMENT AFTER SAID FIRST VALVE MEANS IS OPERATED THEREBY TO INITIATE SAID VENTING, TO EFFECT VENTING OF FLUID UNDER PRESSURE FROM SAID OPPOSITE SIDE OF SAID MOVABLE ABUTMENT AND FROM THE QUICK SERVICE CHAMBER TO ATMOSPHERE TO CAUSE SAID MOVABLE ABUTMENT TO THEREAFTER SHIFT IN THE OPPOSITE DIRECTION TO OPERATE SAID FIRST VALVE MEANS TO TERMINATE SAID VENTING OF FLUID UNDER PRESSURE FROM SAID ONE SIDE OF SAID MOVABLE ABUTMENT AND FOR, THE BRAKE PIPE TO ATMOSPHERE, WHEREBY SAID MOVABLE ABUTMENT IS RENDERED EFFECTIVE TO OPERATE SAID SECOND VALVE MEANS, AFTER SAID FIRST VALVE MEANS HAS TERMINATED SAID VENTING, TO TERMINATE THE VENTING OF FLUID UNDER PRESSURE FROM SAID OPPOSITE SIDE OF SAID MOVABLE ABUTMENT AND FROM THE QUICK SERVICE CHAMBER TO ATMOSPHERE.