Fluid pressure one-way jar

Claim 1

A FLUID PRESSURE ONE-WAY JAR COMPRISING AN UPPER ELONGATED TUBULAR MEMBER PROVIDING A TORQUE BARREL, A CYLINDER REMOVABLY SECURED TO THE LOWER END OF SAID BARREL, AN ELONGATED SLEEVE SECURED TO THE LOWER END OF SAID CYLINDER, AN ANNULAR SHOULDER IN THE UPPER END OF SAID BARREL PROVIDING A DOWNWARDLY FACING IMPACT SURFACE, A HOLLOW TORQUE MANDREL SLIDABLY RECEIVED IN SAID BARREL, MEANS TO PREVENT ROTATION OF SAID MANDREL WITH RESPECT TO SAID BARREL, MEANS ON THE UPPER END OF SAID MANDREL FOR ATTACHING THE SAME TO A DRILL STRING, A COUPLING SLEEVE REMOVABLY SECURED TO THE LOWER END OF SAID MANDREL AND PROVIDING AN ENLARGED HAMMER PORTION HAVING AN UPWARDLY FACING STRIKING SURFACE, A TUBULAR PISTON ROD REMOVABLY SECURED TO SAID COUPLING SLEEVE AND EXTENDING DOWNWARDLY THROUGH SAID CYLINDER AND INTO SAID ELONGATED SLEEVE, SAID CYLINDER HAVING AN ENLARGED INTERNAL PORTION EXTENDING FROM A POINT ADJACENT THE UPPER END TO A POINT INTERMEDIATE THE LENGTH AND TERMINATING IN AN INWARDLY TAPERED WALL MERGING INTO A PORTION OF REDUCED DIAMETER EXTENDING TO THE LOWER END OF SAID CYLINDER AND A PISTON ON SAID PISTON ROD WITHIN SAID CYLINDER, SAID PISTON COMPRISING AN ANNULAR FLANGE ON SAID PISTON ROD, A PISTON RING OF YIELDABLE MATERIAL SLIDABLY MOUNTED ON SAID PISTON ROD AND SUPPORTED ON THE UPPER SURFACE OF SAID FLANGE, MEANS ON SAID PISTON ROD TO LIMIT SLIDING MOVEMENT OF SAID PISTON RING AND FLUID BY-PASS GROOVES IN SAID PISTON ROD INWARDLY