Method for rounding flat-oval tubing

Claim 1

A method of rounding an end of oval tubing which has transverse webs dividing the interior thereof into separate chambered conduits which extend the length of the tubing, said method comprising: longitudinally cutting the webs in the end of the tubing to a desired transition region; reforming the webs at the end of the longitudinal cut into a curved surface; and belling out the end of the tubing to form a substantially cylindrical rounded end.

Claim 2

A method of rounding an end of oval tubing which has transverse webs dividing the interior thereof into separate chambered conduits which extend the length of the tubing, said method comprising: longitudinally cutting the webs in the end of the tubing to a desired transition region; reforming the webs at the end of the longitudinal cut into a curved surface; and belling out the end of the tubing to form a substantially cylindrical rounded end.

Claim 6

A method of rounding a fixtured receiving end of an aluminum flat-oval tubing of the kind used for fluid cooling applications in which said tubing is divided by integral, transverse webs into separate chambered conduits extending the length of the tubing, said method comprising: (A) setting a reinforcing collar about the periphery of the flat-oval tubing at a desired transition region at which the flat-oval tubing is to become rounded; (B) cutting the webs in the fixture receiving end of the tubing longitudinally, cutting each web substantially at its midpoint, said cutting step comprising: (1) registering pilots protruding from a transverse cutting edge of a chisel knife tool into the chambered conduits at the fixture receiving end of the flat-oval tubing; (2) advancing the cutting edge of the chisel knife tool into the fixture receiving end of the tubing until the cutting edge reaches the desired transition region, thereby severing the webs to the transition region; and (3) withdrawing the chisel knife tool from the fixture receiving end of the flat-oval tubing after it has been advanced to form a cut line of web separation substantially adjacent to the transition point; (C) reforming the webs at the cut line of web separation to a full radius curve, said reforming steps comprising: (1) inserting an end forming blade tool into the fixture receiving end of the flat-oval tubing; (2) forming the webs at the line of web separation by contact with the end forming blade tool; and (3) withdrawing the end forming blade tool from the fitting end of the tubing; (D) belling out the fixture receiving end of the tubing to a cylindrical shape, said belling out comprising: (1) registering perpherial grooves in a male arbor with the several webs presented at the fixture receiving end of the flat-oval tubing; (2) inserting the registered male arbor into the fixture receiving end of the flat-oval tubing causing the inner diameter to take on the shape of the male arbor; and (3) withdrawing the male arbor after it has been inserted substantially as far as the desired transition region; and (E) swaging the outer periphery of the fixture receiving end of the tubing, said swaging operation comprising: (1) advancing the reducing mandrel over the outer periphery of the fixture receiving end of the tubing; (2) removing the mandrel from engagement with the flat-oval tubing; and (3) repeating the foregoing swaging steps with progressively smaller mandrels until the outside diameter of the fixture receiving end of the flat-oval tubing is reduced to the desired diameter.

Claim 7

A method of rounding a fixtured receiving end of an aluminum flat-oval tubing of the kind used for fluid cooling applications in which said tubing is divided by integral, transverse webs into separate chambered conduits extending the length of the tubing, said method comprising: (A) setting a reinforcing collar about the periphery of the flat-oval tubing at a desired transition region at which the flat-oval tubing is to become rounded; (B) cutting the webs in the fixture receiving end of the tubing longitudinally, cutting each web substantially at its midpoint, said cutting step comprising: (1) registering pilots protruding from a transverse cutting edge of a chisel knife tool into the chambered conduits at the fixture receiving end of the flat-oval tubing; (2) advancing the cutting edge of the chisel knife tool into the fixture receiving end of the tubing until the cutting edge reaches the desired transition region, thereby severing the webs to the transition region; and (3) withdrawing the chisel knife tool from the fixture receiving end of the flat-oval tubing after it has been advanced to form a cut line of web separation substantially adjacent to the transition point; (C) reforming the webs at the cut line of web separation to a full radius curve, said reforming steps comprising: (1) inserting an end forming blade tool into the fixture receiving end of the flat-oval tubing; (2) forming the webs at the line of web separation by contact with the end forming blade tool; and (3) withdrawing the end forming blade tool from the fitting end of the tubing; (D) belling out the fixture receiving end of the tubing to a cylindrical shape, said belling out comprising: (1) registering perpherial grooves in a male arbor with the several webs presented at the fixture receiving end of the flat-oval tubing; (2) inserting the registered male arbor into the fixture receiving end of the flat-oval tubing causing the inner diameter to take on the shape of the male arbor; and (3) withdrawing the male arbor after it has been inserted substantially as far as the desired transition region; and (E) swaging the outer periphery of the fixture receiving end of the tubing, said swaging operation comprising: (1) advancing the reducing mandrel over the outer periphery of the fixture receiving end of the tubing; (2) removing the mandrel from engagement with the flat-oval tubing; and (3) repeating the foregoing swaging steps with progressively smaller mandrels until the outside diameter of the fixture receiving end of the flat-oval tubing is reduced to the desired diameter.

Claim 8

A method of rounding a fixture receiving end of an aluminum flat-oval tubing of the kind used for heat transfer applications in which said tubing is divided by integral, transverse webs into separate chambered conduits extending the length of the tubing, said method comprising: (A) severing the webs in the fixture receiving end of the tubing longitudinally, severing each web substantially at its midpoint, to a depth that places a point of web separation within a desired transition region, thereby producing severed webs; (B) reforming the webs at the point of web separation to a curve; (C) registering peripheral grooves in a male arbor having a circular cross-section with the severed webs present at the fixture receiving end of the oval tubing; (D) driving the male arbor into the fixture receiving end of the tubing after registration, causing an inner wall of the tubing to conform to an outer surface of the male arbor up to the transition region, thereby forming a rounded end on said tubing; (E) withdrawing the male arbor; and (F) swaging an outer periphery of the fixture receiving end of the tubing with a mandrel to reduce the outside diameter of the rounded end to a standard diameter.

Claim 9

A method of rounding a fixture receiving end of an aluminum flat-oval tubing of the kind used for heat transfer applications in which said tubing is divided by integral, transverse webs into separate chambered conduits extending the length of the tubing, said method comprising: (A) severing the webs in the fixture receiving end of the tubing longitudinally, severing each web substantially at its midpoint, to a depth that places a point of web separation within a desired transition region, thereby producing severed webs; (B) reforming the webs at the point of web separation to a curve; (C) registering peripheral grooves in a male arbor having a circular cross-section with the severed webs present at the fixture receiving end of the oval tubing; (D) driving the male arbor into the fixture receiving end of the tubing after registration, causing an inner wall of the tubing to conform to an outer surface of the male arbor up to the transition region, thereby forming a rounded end on said tubing; (E) withdrawing the male arbor; and (F) swaging an outer periphery of the fixture receiving end of the tubing with a mandrel to reduce the outside diameter of the rounded end to a standard diameter.

Claim 10

A method of rounding a fixtured receiving end of an aluminum flat-oval tubing of the kind used for fluid cooling applications in which said tubing is divided by integral, transverse webs into separate chambered conduits extending the length of the tubing, said method comprising; (A) cutting the webs in the fixture receiving end of the tubing longitudinally, cutting each web substantially at its midpoint, said cutting step comprising; (1) registering at least one pilot protruding from a transverse cutting edge of a chisel knife tool into at least one of the chambered conduits at the fixture receiving end of the flat-oval tubing; (2) advancing the cutting edge of the chisel knife tool into the fixture receiving end of the tubing until the cutting edge reaches a desired transition region, thereby severing the webs to the transition region; and (3) withdrawing the chisel knife tool from the fixture receiving end of the flat-oval tubing after it has been advanced to form a cut line of web separation substantially adjacent to the transition point; (B) reforming the webs at the cut line of web separation to a curve, said reforming steps comprising: (1) inserting an end forming blade tool into the fixture receiving end of the flat-oval tubing; (2) forming the webs at the line of web separation by contact with the end forming blade tool; and (3) withdrawing the end forming blade tool from the fitting end of the tubing; (C) belling out the fixture receiving end of the tubing to a substantially cylindrical shape, said belling out comprising: (1) registering peripheral grooves in a male arbor with the severed webs presented at the fixture receiving end of the flat-oval tubing; (2) inserting the registered male arbor into the fixture receiving end of the flat-oval tubing, causing the inner diameter to take on the shape of the male arbor; and (3) withdrawing the male arbor after it has been inserted substantially as far as the desired transition region; and (D) swaging the outer periphery of the fixture receiving end of the tubing, said swaging operation comprising: (1) advancing the reducing mandrel over the outer periphery of the fixture receiving end of the tubing; (2) removing the mandrel from engagement with the flat-oval tubing; and (3) repeating the foregoing swaging steps with progressively smaller mandrels until the outside diameter of the fixture receiving end of the flat-oval tubing is reduced to the desired diameter.

Claim 11

A method of rounding a fixtured receiving end of an aluminum flat-oval tubing of the kind used for fluid cooling applications in which said tubing is divided by integral, transverse webs into separate chambered conduits extending the length of the tubing, said method comprising; (A) cutting the webs in the fixture receiving end of the tubing longitudinally, cutting each web substantially at its midpoint, said cutting step comprising; (1) registering at least one pilot protruding from a transverse cutting edge of a chisel knife tool into at least one of the chambered conduits at the fixture receiving end of the flat-oval tubing; (2) advancing the cutting edge of the chisel knife tool into the fixture receiving end of the tubing until the cutting edge reaches a desired transition region, thereby severing the webs to the transition region; and (3) withdrawing the chisel knife tool from the fixture receiving end of the flat-oval tubing after it has been advanced to form a cut line of web separation substantially adjacent to the transition point; (B) reforming the webs at the cut line of web separation to a curve, said reforming steps comprising: (1) inserting an end forming blade tool into the fixture receiving end of the flat-oval tubing; (2) forming the webs at the line of web separation by contact with the end forming blade tool; and (3) withdrawing the end forming blade tool from the fitting end of the tubing; (C) belling out the fixture receiving end of the tubing to a substantially cylindrical shape, said belling out comprising: (1) registering peripheral grooves in a male arbor with the severed webs presented at the fixture receiving end of the flat-oval tubing; (2) inserting the registered male arbor into the fixture receiving end of the flat-oval tubing, causing the inner diameter to take on the shape of the male arbor; and (3) withdrawing the male arbor after it has been inserted substantially as far as the desired transition region; and (D) swaging the outer periphery of the fixture receiving end of the tubing, said swaging operation comprising: (1) advancing the reducing mandrel over the outer periphery of the fixture receiving end of the tubing; (2) removing the mandrel from engagement with the flat-oval tubing; and (3) repeating the foregoing swaging steps with progressively smaller mandrels until the outside diameter of the fixture receiving end of the flat-oval tubing is reduced to the desired diameter.