Grease gun and cartridge combination

Claim 1

IN A GREASE GUN HAVING A ELONGATED CYLINDRICAL BARREL EXTERNALLY THREADED ON THE FORWARD END PORTION THEREOF, AND A LEVER-OPERATED GREASE DISPENSING HEAD PROVIDING AN INTERNALLY THREADED CUP-SHAPED CAP THREADEDLY RECEIVED ON SAID BARREL FORWARD END PORTION, THE COMBINATION COMPRISING AN ANNULAR GASKET OF RESILIENT, COMPRESSIABLE MATERIAL INTERPOSED BETWEEN THE FRONT END OF SAID BARREL AND SAID CAP AND EXTENDING INWARDLY BEYOND THE WALL OF SAID BARREL FOR A DISTANCE AT LEAST AS GREAT AS THE THICKNESS OF SAID BARREL WALL AND COMPLETELY THEREAROUND, A CYLINDRICAL GREASE-CONTAINING CARTRIDGE DISPOSED WITHIN SAID BARREL, THE CYLINDRICAL WALL OF SAID CARTRIDGE BEING FORMED OF A NON-METALLIC MATERIAL AND TERMINATING IN FORWARD AND REAR ENDS PROVIDING SURFACES LYING PLANES, SUBSTANTIALLY AT RIGHT ANGLES TO THE AXIS AND OF SAID CARTRIDGE, SAID CARTRIDGE WALL FORWARD END BEING IN DIRECT CONTACT WITH THE INWARDLY EXTENDING PORTION OF SAID GASKET, SAID GASKET HAVING A REARWARDLY EXTENDING PROJECTION BEARING AGAINST THE INSIDE OF SAID CARTRIDGE WALL, STOP MEANS DISPOSED WITHIN THE REARWARD PORTION OF SAID BARREL, SAID STOP MEANS PROVIDING AN ANNULAR ABUTMENT IN DIRECT CONTACT WITH THE SAID REAR END OF SAID CARTRIDGE WALL FOR RESTRAINING FURTHER REARWARD MOVEMENT OF SAID CARTRIDGE AS SAID GASKET IS FORCED INTO ENGAGEMENT WITH THE FORWARD END OF SAID CARTRIDGE BY TIGHTENING SAID CAP ON SAID BARREL, THE COOPERATING THREADED PORTIONS OF SAID CAP AND BARREL PEMITTING SAID CAP TO BE TIGHTENED ON SAID BARREL UNTIL AND CARTRIDGE WALL FORWARD END SEALINGLY ENGAGES THE SAID INWARDLY EXTENDING PORTION OF SAID GASKET.