Pneumatic hammer

Claim 1

A PNEUMATIC MOTOR COMPRISING A PNEUMATIC CYLINDER AND A PNEUMATIC RESERVOIR, SAID CYLINDER AND RESERVOIR INTERCOMMUNICATING THROUGH A PORT IN ONE END OF SAID CYLINDER, A PISTON OPERABLE IN SAID CYLINDER AND HAVING A PISTON ROD EXTENDING SEALINGLY THROUGH AN OPPOSITE END OF SAID CYLINDER, SAID PISTON HAVING A FACE AT ITS HEAD END WITH ITS PLANE NORMAL TO THE PISTON AXIS, SAID PORT OF LESS AREA THAN THE AREA OF THE PISTON HEAD FACE, THE PISTON HEAD FACE WHEN SAID PISTON IS AT ITS INNER LIMIT OF TRAVEL ADAPTED TO ABOT SAID PORT TO CLOSE IT, AND VALVE MEANS ADAPTED WHEN IN ONE POSITION TO CONNECT SAID CYLINDER IN A POSITION BENEATH SAID PISTON TO A SUPPLY OF COMPRESSED AIR AND TO CONNECT SAID RESERVOIR TO EXHAUST WHEREBY TO MOVE SAID PISTON FOR ITS HEAD FACE TO ABOUT AND CLOSE SAID PORT, AND SAID VALVE MEANS WHEN IN ANOTHER POSITION ADAPTED TO CONNECT SAID RESERVOIR TO SAID SUPPLY AND SAID CYLINDER TO EXHAUST SUCH THAT WHEN THE FORCE DUE TO THE CONSEQUENT RISING OF PRESSURE IN SAID RESERVOIR ACTING ON THE AREA OF SAID PISTON HEAD FACE EXPOSED BY SAID PORT EXCEEDS THE FORCE DUE TO THE DIMINISHING PRESSURE IN THE EXHAUSTING CYLINDER ACTING BENEATH SAID PISTON, SAID PISTON WILL MOVE TO UNSEAL SAID PORT SUDDENLY AND ADMIT PRESSURISED AIR FROM SAID RESERVOIR AND SAID SUPPLY TO ACT ON THE WHOLE AREA OF THE PISTON HEAD FACE TO PROVIDE MAXIMUM ACCELERATION FOR SAID PISTON, AND AUTOMATIC MEANS OPERATED BY THE PREVAILING PRESSURE IN THE CYLINDER AND INTERCONNECTED TO SAID VALVE MEANS FOR MOVING SAID VALVE MEANS TO AND FROM ITS TWO POSITIONS