Cut-off device for tube making machine of continuous type

Claim 1

IN A CUT-OFF DEVICE FOR A TUBE IN CONTINUOUS LONGITUDINAL MOTION, A CARRIAGE HAVING SAID TUBE THREADED THROUGH IT AND MOVABLE IN A STRAIGHT RECIPROCAL PATH OF A PREDETERMINED LENGTH SUBSTANTIALLY PARALLEL TO THE TUBE, THE MOVEMENT OF SAID CARRIAGE FROM ITS STARTING POSITION TO THE FORWARDMOST POSITION AND ITS RETURN TO THE STARTING POSITION FORMING ONE CUTTING CYCLE OF THE DEVICE, LOCKING MEANS CARRIED BY SAID CARRIAGE AND OPERABLE TO LOCK SAID CARRIAGE TO THE TUBE AT THE BEGINNING OF THE CYCLE FOR HAVING THE CARRIAGE MOVE WITH THE TUBE TO THE FORWARD TERMINAL POINT OF SAID PATH AND TO RELEASE THE CARRIAGE FROM THE TUBE AT SAID TERMINAL POINT, SPRING MEANS RETURNING THE CARRIAGE TO ITS ORIGINAL POSITION UPON RELEASE OF THE TUBE BY SAID LOCKING MEANS; TWO CUTTERS, EACH CARRIED BY SAID CARRIAGE AND SEPARATELY MOVABLE THEREIN TRANSVERSELY OF THE TUBE THROUGH A CUTTING STROKE AND A RETURN STROKE, MEANS TO MOVE THE FIRST OF SAID CUTTERS THROUGH IT CUTTING STROKE TO CUT A NOTCH THROUGH THE THICKNESS OF THE TUBE WALL AND TO PROCEED FURTHER IN THE FORWARD DIRECTION TOWARD A POSITION COMPLETELY OUT OF THE WAY OF THE SECOND CUTTER AND TO REMAIN STATIONARY IN SUCH POSITION WHILE THE SECOND CUTTER MOVES AT LEAST UNTIL SAID SECOND CUTTER ENTERED SAID NOTCH; AND MEANS TO MOVE SAID SECOND CUTTER THROUGH SAID NOTCH AND THE REMAINING PORTION OF THE TUBE CROSS SECTION TO CUT OFF THE TUBE AND TO RETURN SAID SECOND CUTTER TO ITS ORIGINAL POSITION IN THE CARRIAGE.