Valve

Claim 1

A VALVE COMPRISING (A) A HOUSING CONTAINING FOUR PORTS; (B) A VALVE BORE INTERSECTED BY TWO LONGITUDINALLY SPACED PASSAGES, THERE BEING A FIRST PASSAGE WHICH COMMUNICATES WITH THE FIRST PORT AND A SECOND PASSAGE WHICH COMMUNICATES WITH THE SECOND PORT; (C) A THIRD PASSAGE INTERCONNECTING THE THIRD AND FOURTH PORTS; (D) A FLOW CONTROL VALVE RECIPROCABLE IN THE BORE BETWEEN FIRST AND SECOND POSITIONS IN WHICH IT CLOSES AND OPENS, RESPECTIVELY, COMMUNICATION BETWEEN THE FIRST AND SECOND PASSAGES THROUGH THE VALVE BORE, THE FLOW CONTROL VALVE CARRYING MEANS WHICH COOPERATES WITH THE WALL OF THE BORE TO THROTTLE PROGRESSIVELY SAID COMMUNICATION AS THE VALVE MOVES TOWARD THE FIRST POSITION; (E) SPRING MEANS BIASING THE FLOW CONTROL VALVE TOWARD THE FIRST POSTION; (F) MEANS DEFINING A DAMPING CHAMBER IN RESTRICTED COMMUNICATION WITH THE SECOND PASSAGES AND ENCLOSING ONE END OF THE FLOW CONTROL VAVLE; (G) MEANS AT THE OTHER END OF THE FLOW CONTROL VALVE RESPONSIVE TO THE PRESSURE IN THE THIRD PASSAGE FOR URGING THE FLOW CONTROL VALVE TOWARD THE SECOND POSITION; (H) AN INTERNAL PASSAGE IN THE FLOW CONTROL VALVE INTERSECTED BY FIRST AND SECOND LONGITUDINALLY SPACED TRANSVERSE PASSAGES THAT OPEN THROUGH THE OUTER PERIPHERY OF THE FLOW CONTROL VALVE AND REGISTER WITH THE FIRST AND SECOND PASSAGES, RESPECTIVELY, WHEN THE FLOW CONTROL VALVE IS IN THE FIRST POSITION; (I) A FIRST CHECK VALVE LOCATED IN THE INTERNAL PASSAGE AND ARRANGED TO PREVENT FLOW FROM THE FIRST TRANSVERSE PASSAGE TO THE SECOND TRANSVERSE PASSAGE THROUGH THE INTERNAL PASSAGE BUT TO PERMIT FLOW IN THE REVERSE DIRECTION; (J) BIASING MEANS, INCLUDING MEANS RESPONSIVE TO THE PRESSURE IN THE FIRST PASSAGE AND A SPRING, URGING THE FIRST CHECK VALVE CLOSED; (K) A BY-PASS PASSAGE INTERCONNECTING THE FIRST AND THIRD PASSAGES; (L) A SECOND CHECK VALVE ARRANGED TO PREVENT FLOW FROM THE THIRD PASSAGE TO THE BY-PASS PASSAGE BUT TO PERMIT FLOW IN THE REVERSE DIRECTION; (M) A CONTROL CHAMBER HAVING A RESTRICTED INLET CONNECTION LEADING TO THE PASSAGE AND AN OUTLET CONNECTION; (N) A BY-PASS VALVE CONTROLLING COMMUNICATION BETWEEN THE FIRST PASSAGE AND THE BY-PASS PASSAGE; (O) SPRING BIASING THE BY-PASS VALVE CLOSED; AND (P) MEANS RESPONSIVE TO THE PRESSURE DIFFERENTIAL BETWEEN THE FIRST PASSAGE AND THE CONTROL CHAMBER FOR MOVING THE BY-PASS VALVE IN THE OPENING DIRECTION.