Fluid seal for a reciprocating shaft

Claim 1

A FLUID SEAL ARRANGEMENT FOR A RECIPROCATING SHAFT EXTENDING INTO A VESSEL CONTAINING FLUID UNDER PRESSURE COMPRISING: A HOUSING A SHOULDER ON THE HOUSING AND ADJACENT SAID SHAFT; FLUID SEALING MEANS ON SAID SHOULDER; A PACKING GLAND FOR PRESSING THE FLUID SEALING MEANS INTO FLUID SEALING ENGAGEMENT AGAINST THE SHAFT; A BELLOWS MOUNTED WITHIN SAID HOUSING BELOW THE FLUID SEALING MEANS AND SECURED TO SAID HOUSING IN A FLUID TIGHT MANNER, SAID BELLOWS BEING COAXIAL WITH THE SHAFT AND OF LARGER INSIDE DIAMETER THAN THE DIAMETER OF SAID SHAFT SO THAT THE INSIDE OF THE BELLOWS IS IN FLUID COMMUNICATION WITH THE INSIDE OF THE VESSEL; MEANS FOR LOCKING THE TOP OF THE BELLOWS TO THE SHAFT; SAID HOUSING BEING FILLED WITH FLUID OUTSIDE OF THE BELLOWS AND HAVING A PORT IN FLUID COMMUNICATION INTERNALLY OF THE HOUSING AND EXTERNAL OF THE BELLOWS, AND A PORT IN FLUID COMMUNICATION INTERNALLY OF THE BELLOWS; PRESSURE MEANS EXTERNAL TO THE HOUSING AND FLUIDLY CONNECTED TO SAID PORTS; AND MEANS FOR SELECTIVELY SUPPLYING PRESSURE FLUID TO EACH OF SAID PORTS, AND INCLUDING MEANS FOR DAMPING PRESSURE SURGES ENGENDERED BY MOVEMENTS OF THE BELLOWS AND THE SHAFT.