Percussion cylinder device with pneu-matically cushioned back-stroke

Claim 1

A POWER CYLINDER, COMPRISING: (A) A CYLINDRICAL BODY HAVING A CHAMBER THEREIN AND HAVING END WALLS THEREON, (B) A PISTON DISPOSED IN SAID CHAMBER FOR RECIPROCABLE MOVEMENT THEREIN AND DIVIDING SAID CHAMBER INTO A FIRST CHAMBER ON ONE SIDE OF SAID PISTON AND A SECOND CHAMBER ON THE OTHER SIDE OF SAID PISTON, (C) HOLLOW STEM MEANS CONNECTED TO THE OTHER SIDE OF SAID PISTON AND SLIDABLY EXTENDING THROUGH ONE OF SAID END WALLS FOR RECIPROCABLE MOVEMENT WITH SAID PISTON, SAID STEM HAVING A SLIGHTLY SMALLER DIAMETER THAN THAT OF SAID PISTON FOR REDUCING THE EFFECTIVE FACE AREA OF SAID OTHER SIDE OF SAID PISTON WITH RESPECT TO THE SAID ONE SIDE OF SAID PISTON, (D) PORT MEANS IN SAID STEM INTERCOMMUNICATING THE INTERIOR THEREOF WITH SAID SECOND CHAMBER, (E) SAID FIRST AND SECOND CHAMBERS BEING ADAPTED FOR CONNECTION TO A SOURCE OF FLUID PRESSURE WHEREBY THE SIMULTANEOUS APPLICATION OF THE SAME FLUID PRESSURE TO BOTH THE FIRST CHAMBER AND THE SECOND CHAMBER INITIALLY PROVIDES A PREPONDERANT FORCE ON SAID ONE SIDE OF SAID PISTON TO EFFECT MOVEMENT THEREOF AND EFFECTING A DIMINUTION OF THE SIZE OF THE SECOND CHAMBER WHICH PROVIDES AN INCREASE IN FORCE ON SAID OTHER SIDE OF SAID PISTION FOR EFFECTING A CUSHIONED STOPPAGE OF THE PISTON MOVEMENT, AND (F) CHECK VALVE MEANS FOR RETAINING FLUID PRESSURE IN SAID SECOND CHAMBER WHEN SAID FIRST CHAMBER IS CONNECTED TO EXHAUST WHEREBY THE PISTON IS RETURNED TO ITS ORIGINAL POSITION BY THE RESULTANT PREPONDERANT PRESSURE ON SAID OTHER SIDE OF SAID PISTON, (G) SAID PORTS ON SAID STEM BEING SPACED FROM SAID PISTON A PREDETERMINED DISTANCE WHEREBY SAID PORTS PASS THROUGH SAID ONE END WALL FOR DISPOSITION EXTERNALLY OF SAID CYLINDRICAL BODY TO COMMUNICATE THE INTERIOR OF SAID STEM TO ATMOSPHERE WHEN THE PISTON HAS MOVED TO A PREDETERMINED LIMIT WITHIN SAID CYLINDRICAL BODY.