Pressure equalizing means for compressors and the like

Claim 1

IN A COMPRESSOR HAVING MEANS DEFINING A PRESSURE CHAMBER, MEANS DEFINING A SUCTION CHAMBER, AND MEANS FOR PUMPING FLUID FROM SAID SUCTION CHAMBER TO SAID PRESSURE CHAMBER, MEANS FOR CAUSING THE PRESSURE IN SAID PRESSURE CHAMBER AND SUCTION CHAMBER TO BE SUBSTANTIALLY EAUAL DURING INITIATION OF OPERATION OF SAID PUMPING MEANS AND PERMITTING THE CHAMBERS TO HAVE A PRESSURE DIFFERENTIAL THEREBETWEEN DURING SUBSEQUENT OPERATION OF THE PUMPING MEANS, COMPRISING: MEANS DEFINING AN EQUALIZATION PASSAGE BETWEEN SAID PRESSURE CHAMBER AND SUCTION CHAMBER; MEANS FOR CLOSING SAID EQUALIZATION PASSAGE AS A RESULT OF INITIATION OF OPERATION OF SAID PUMPING MEANS INCLUDING VALVE MEANS HAVING A MOVABLE VALVE MEMBER FOR SELECTIVELY CLOSING SAID EQUALIZATION PASSAGE, AND MEANS BIASING SAID VALVE MEMBER TO OPEN SAID EQUALIZATION PASSAGE WHEN THE PUMPING MEANS IS INOPERATIVE; AND MEANS FOR APPLYING PRESSURE DEVELOPED BY OPERATION OF SAID PUMPING MEANS TO SAID VALVE MEANS FOR DELAYEDLY MOVING SAID VALVE MEMBER IN OPPOSITION TO SAID BIASING MEANS TO CLOSE SAID EQUALIZATION PASSAGE AFTER A PRESELECTED PERIOD OF TIME, SAID VALUE MEANS COMPRISING MEANS DEFINING A BORE, SAID EQUALIZATION PASSAGE HAVING AN INLET OPENING INTO SAID BORE, SAID AN OUTLET OPENING OUTWARDLY FROM SAID BORE, SAID VALVE MEMBER COMPRISING A SLUG MOVABLE IN SAID BORE FOR SELECTIVELY BLOCKING FLOW FLUID BETWEEN SAID INLET AND OUTLET, AND SAID SLUG INCLUDING A LOWER PORTION AND A TRANSVERSELY REDUCED UPPER PORTION, SELECTIVELY ALIGNED WITH SAID INLET AND OUTLET AND PERMITTING FLUID FLOW THEREAROUND THROUGH SAID BORE, AND SPACED FROM ALIGNMENT WITH SAID INLET AND OUTLET WITH SAID LOWER PORTION DISPOSED TO BLOCK SAID FLUID FLOW.