Plugging apparatus for pipe lines

Claim 1

AN APPARATUS FOR PLUGGING A PIPE UNDER PRESSURE COMPRISING MEANS FOR CUTTING AN OPENING HAVING A DIAMETER LESS THAN THE DIAMETER OF SAID PIPE THROUGH THE SIDE WALL OF SAID PIPE WHILE PREVENTING LOSS OF PRESSURE FROM SAID PIPE, A VALVE OPERABLE TO CLOSE SAID OPENING, A PRESSURE CHAMBER CONNECTABLE WITH SAID OPENING THROUGH SAID VALVE, MEANS INSERTABLE THROUGH SAID PRESSURE CHAMBER FOR CLEANING SAID PIPE ADJACENT TO SAID OPENING, A FLEXIBLE BAG, MEANS FOR INSERTING SAID FLEXIBLE BAG THROUGH SAID PRESSURE CHAMBER AND SAID OPENING INTO SAID PIPE AND PRODUCING A PRESSURE WITHIN SAID BAG AT LEAST EQUAL TO THE PRESSURE IN SAID PIPE, RELIEF MEANS OPERABLE TO PREVENT PRESSURE IN SAID BAG SUBSTANTIALLY GREATER THAN THE PRESSURE IN SAID PIPE, A MASS OF LOOSE MAGNETIC PARTICLES, MEANS FOR INSERTING SAID LOOSE MAGNETIC PARTICLES THROUGH SAID OPENING INTO SAID BAG, MEANS EXTERNAL OF SAID PIPE OPERABLE TO PRODUCE A MAGNETIC FIELD EXTENDING THROUGH SAID PARTICLES MAGNETICALLY LOCKING SAID PARTICLES AS A RIGID MASS AND PRESSING SAID BAG INTO ENGAGEMENT WITH THE WALL OF SAID PIPE, MEANS FOR REMOVING SAID PARTICLES FROM SAID BAG, AND MEANS FOR REMOVING SAID BAG FROM SAID PIPE THROUGH SAID OPENING.