Outlet check valve means for a grease gun head

Claim 1

IN COMBINATION WITH A GREASE GUN HEAD INCLUDING AN ELONGATED TUBULAR BODY HAVING A LONGITUDINAL BORE EXTENDING THERETHROUGH WITH AN INTERMEDIATE PORTION PROVIDING A HIGH PRESSURE CYLINDER, SAID CYLINDER HAVING AN INLET END AND AND OUTLET END, A GREASE INLET PORT EXTENDING THROUGH THE WALL OF SAID TUBULAR BODY ADJACENT SAID INLET END, AND A PISTON RECIPROCATING IN SAID CYLINDER BETWEEN SAID INLET AND OUTLET ENDS, AND OUTLET CHECK VALVE ASSEMBLY COMPRISING A HOLLOW CYLINDRICAL VALVE CAGE SEATED IN SAID BORE ADJACENT THE OUTLET END OF SAID HIGH PRESSURE CYLINDER AND HAVING AN OPEN END FACING AWAY FROM SAID CYLINDER, THE OTHER END OF SAID VALVE CAGE BEING CLOSED AND PROVIDING A TRANSVERSELY-EXTENDING WALL DEFINING THE OUTER END OF SAID CYLINDER, AND WALL PROVIDING A GREASE OUTLET PORT, A MOVABLE VALVE WITHIN SAID CAGE FOR CLOSING SAID PORT, SAID VALVE BEING IN THE FORM OF AN ELONGATED CYLINDRICAL MEMBER HAVING AN ENLARGED HEAD EXTENDING INTO SAID VALVE CAGE AND A REDUCED SHANK EXTENDING OUTWARDLY BEYOND SAID CAGE, SAID HEAD PROVIDING A FACE COOPERATING WITH THE TRANSVERSELY-EXTENDING WALL OF SAID CAGE TO CLOSE SAID OUTLET PORT WHEN URGED AGAINST SAID WALL, SAID SHANK BEING PROVIDED WITH AN ANNULAR GROOVE ADJACENT SAID HEAD, AND A CONICAL COMPRESSION SPRING HAVING ITS END PORTION OF REDUCING DIAMETER RECEIVED ON SAID SHANK WITH THE LAST TURN THEREOF RETAINED IN SAID ANNULAR GROOVE, THE PORTION OF SAID BORE ADJACENT THE ENLARGED END PORTION OF SAID CONICAL SPRING BEING PROVIDED WITH THREADS AND WHEREIN AT LEAST THE LARGEST DIAMETER TURN OF SAID SPRING UNDER THE SAID THREADS OF SAID BORE FOR HOLDING SAID SPRING UNDER COMPRESSION PERMITTING SAID SPRING AND VALVE TO BE INSERTED AND REMOVED BY ROTATION THEREOF WITH RESPECT TO SAID THREADED PORTION.