Arc-extinguishing circuit breaker with enclosed gas space

Claim 1

A CIRCUIT BREAKER COMPRISING A COMPLETELY CLOSED EXTINGUISHING CHAMBER FILLER WITH GAS AND HAVING A CLOSED CYLINDRICAL PORTION, A PISTON SLIDABLE IN THE CYLINDRICAL PORTION AND DIVIDING THE CHAMBER INTO AN ARC CHAMBER HAVING AN END WALL AND A PRESSURE GENERATING CHAMBER, THE CROSS-SECTION OF THE PISTON AT THE END NEAREST SAID END WALL BEING EQUAL TO THE INTERNAL CROSS-SECTION OF THE CLOSED CYLINDRICAL PORTION, A STATIONARY CONTACT WITHIN THE ARC CHAMBER, A MOVABLE CONTACT PASSING THROUGH SAID PISTON, SAID PISTON BEING SLIDABLY MOUNTED ON THE MOVABLE CONTACT, MEANS FOR MOVING THE MOVABLE CONTACT FROM AND TOWARDS THE STATIONARY CONTACT, SAID MOVABLE CONTACT AND PISTON HAVING COOPERATING MEANS THEREON FOR LIMITING THE SLIDING MOVEMENT OF THE PISTON WITH RESPECT TO THE MOVABLE CONTACT BETWEEN FIRST AND SECOND LIMIT POSITIONS, SAID MOVABLE CONTACT HAVING A TIP, THE TIP OF THE MOVABLE CONTACT BEING COMPLETELY DRAWN INTO THE PISTON WHEN SAID PISTON REACHES ONE OF SAID LIMIT POSITIONS DURING OPENING MOVEMENT, SAID PISTON HAVING AN EXTINGUISHING GAS CHANNEL THERETHROUGH, SAID MOVABLE CONTCT CLOSING SAID GAS CHANNEL IN THE CLOSED POSITION OF THE CIRCUIT BREAKER, SAID COOPERATING MEANS INCLUDING MEANS ALLOWING SAID MOVABLE CONTACT, AS ITS FIRST MOVES AWAY FROM THE STATIONARY CONTACT, TO SLIDE IN SAID PISTON TO AN EXTEND SUFFICIENT TO UNCOVER SAID GAS CHANNEL, SAID COOPERATING MEANS FURTHER INCLUDING MEANS TO MOVE SAID PISTON WITH THE MOVABLE CONTACT DURING FURTHER MOVEMENT OF THE MOVABLE CONTACT AWAY FROM THE STATIONARY CONTACT, SAID PISTON, WHEN SAID CONTACTS ARE CLOSED AND SAID PISTON IS IN THE SECOND LIMIT POSITION, LYING CLOSELY ADJACENT THE END WALL OF THE ARCCHAMBER.