Portable machine tool for conditioning header tube openings for butt-welding tubes
AssigneeTri Tool Inc.
InventorsClement Tremblay, Jerald VanderPol
Life of this patent
Estimating the term…
Abstract
A portable machine tool for removing stub ends of heat exchange tubes from a heat exchanger header or other plate structure and preparing the tube opening in the header for butt-welding a new tube at the opening. The tool includes a mandrel that may be locked within the tube opening and a plurality of stabilizing legs extending between the mandrel and the header for stabilizing the mandrel during machine tool operation. A cutting head is mounted concentrically on the mandrel and is advanced into engagement with the stub end of a heat exchange tube and it's respective opening to remove the stub end and prepare the opening for welding the new tube thereon.
Claims18
A portable machine tool adapted to prepare openings in a plate structure for butt-welding of tubes thereon comprising:
- a longitudinally extending mandrel having a distal end area adapted to be inserted into an opening of a plate structure having inner and outer wall surfaces intersected by the opening, and a proximal end area;
- said distal end area of the mandrel adapted to support a radially extendable stop member and radially extendable centering elements;
- an upper plate associated with the proximal end area of the mandrel, said upper plate transversely extending relative to and longitudinally slidable relative to the proximal end area of the mandrel;
- circumferentially spaced legs secured to the upper plate, each leg extending generally parallel to the mandrel towards the distal end of the mandrel and terminating at a leg distal end;
- lower leg supports connected to and extending transversely of said mandrel, said lower leg supports engaging and supporting said legs against transverse movement relative to the mandrel;
- a leg moving device connected between the upper plate and the proximal end area of the mandrel operable to move the upper plate and the legs relative to the mandrel in a direction towards the distal end area of the mandrel;
- a tool driving system carried by the mandrel;
- a cutting head facing towards the distal end of the mandrel and mounted so as to be movable towards and away from the distal end of the mandrel;
- a feed mechanism operable to cause movement of the cutting head along the mandrel towards and away from the distal end area of the mandrel;
- said tool driving system operable to transmit rotary input motion to the cutting head.
A method of preparing openings in a plate structure having inner and outer surfaces intersected by the openings for butt-welding tubes to the openings at the outer surface of the structure, comprising:
- extending a mandrel through and supporting such mandrel centrally in an opening in alignment with the axis of the opening;
- fixing the mandrel against withdrawal from the opening by a stop member engaging an inner surface of the structure adjacent the opening;
- slidably mounting a transversely extending upper plate on the mandrel;
- mounting a rotary cutting head carrying cutter tool bits on the mandrel for movement along the mandrel toward and away from the distal end area of the mandrel;
- rigidly mounting a plurality of stabilizing legs to the upper plate so the legs extend generally parallel with the mandrel towards the structure;
- causing the upper plate and legs to be driven towards the structure along the mandrel by a force applying device operable between the mandrel and the upper plate that places the mandrel in tension and the legs in compression, with the mandrel tension reacted by the stop member and the leg compression reacted by the outer surface of the structure;
- advancing the machine tool cutter head by a tool feed device along the mandrel towards and into engagement with the opening area of the structure while driving the cutting head in rotation;
- machining the opening area at the outer surface of the structure to a desired form and withdrawing the cutting head from the opening upon completion of the machining step;
- releasing the mandrel from the opening and removing the mandrel and machine tool elements connected to the mandrel from the opening area.
Dependencies are inferred from the claim text.