Pump means

Claim 1

IN COMBINATION, VACUUM PUMP MEANS HAVING MEANS ENCLOSING A VACUUM CHAMBER, RECIPROCATING DIAPHRAGM PISTON MEANS IN SAID CHAMBER, AND INLET AND OUTLET MEANS COMMUNICATING WITH SAID CHAMBER; ROD MEANS CONNECTED TO SAID PISTON MEANS FOR RECIPROCATING THE SAME IN SAID CHAMBER, ROTATABLY DRIVEN SHAFT MEANS, MEANS PIVOTALLY INTERCONNECTING SAID SHAFT MEANS AND ROD MEANS INCLUDING ADJUSTABLE ECCENTRIC MEANS FOR RECIPROCATING SAID ROD MEANS, MEANS FOR SELECTIVELY ADJUSTING SAID ACCENTRIC MEANS TO ACCORDINGLY VARY THE STROKE OF SAID PISTON MEANS, INLET AND OUTLET CHECK VALVE MEANS OVER SAID INLET AND OUTLET MEANS RESPECTIVELY, FOR CONTROLLING THE FLOW OF FLUID UNIDIRECTIONALLY THROUGH SAID CHAMBER ACCORDING TO THE INTAKE AND DISCHARGE STROKES, RESPECTIVELY, OF SAID PISTON MEANS; EACH OF SAID CHECK VALVE MEANS COMPRISING A UNITARY BODY MEMBER HAVING AN INTERNAL CHECK VALVE CHAMBER, SAID BODY MEMBER BEING REMOVABLY INSERTED IN A SOCKET FORMED THEREFOR IN THE CHAMBER ENCLOSING MEANS OF SAID PUMP MEANS, A UNITARY ELASTIC VALVE MEMBER MOUNTED WITHIN SAID VALVE CHAMBER, AND SPRING MEANS AXIALLY BIASING SAID VALVE MEMBER AGAINST A SEAT PROVIDED ADJACENT ONE END OF SAID VALVE CHAMBER TO CONTROL THE FLOW OF FLUID THEREPAST; AND RETAINER MEANS SLIDINGLY ENGAGEABLE WITH RECESSED PORITIONS, FORMED IN THE BODY MEMBER OF EACH OF SAID CHECK VALVE MEANS AND WITH SPACED LOCKING MEANS ON SAID CHAMBER FORMING MEANS, SAID RETAINER MEANS BEING OPERATIVE TO REMOVABLY LOCK SAID VALVE MEANS IN THE SOCKETS THEREFOR.