Devices for disassembling machine parts

Claim 1

IN A DEVICE FOR REMOVING A PISTON FROM A PISTON ROD; A TUBULAR OUTER BODY CONSTRUCTED TO BE CONNECTED TO THE PISTON AND HAVING INTERNAL THREADS; A POWER ELEMENT AXIALLY MOVABLE WITHIN SAID TUBULAR OUTER BODY FOR TRANSMITTING A FORCE TENDING TO SEPARATE THE PISTON FROM THE PISTON ROD, SAID POWER ELEMENT HAVING EXTERNAL THREADS; MEANS CONNECTING SAID POWER ELEMENT AND SAID TUBULAR OUTER BODY TO PERMIT ONLY RELATIVE AXIAL MOVEMENT BETWEEN SAID POWER ELEMENT AND SAID TUBULAR OUTER BODY; A TUBULAR DIFFERENTIAL SCREW ELEMENT SURROUNDING SAID POWER ELEMENT AND HAVING INTERNAL THREADS ENGAGING SAID EXTERNAL THREADS ON SAID POWER ELEMENT; AND HAVING EXTERNAL THREADS ENGAGING SAID INTERNAL THREADS ON SAID TUBULAR OUTER BODY, THE LEAD OF SAID SCREW ELEMENT INTERNAL THREAD BEING GREATER THAN THE LEAD OF SAID SCREW ELEMENT EXTERNAL THREADS, SAID TUBULAR ELEMENT HAVING AN END ADAPTED FOR CONVENIENT ROTATIONAL MANIPULATION.