Method and apparatus for sizing joint rings for cylindrical pipes

Claim 1

A method of sizing metal joint rings for cylindrical pipe, wherein the steps comprise initially expanding a joint ring beyond its elastic limit, stopping said initial expansion of the joint ring to expand the joint ring to a particular size selectably less than its final size, welding the joint ring to the end of the cylindrical pipe, and re-expanding the joint ring beyond its elastic limit to its final size.

Claim 2

A method of sizing metal joint rings for cylindrical pipe, wherein the steps comprise initially expanding a joint ring beyond its elastic limit, stopping said initial expansion of the joint ring to expand the joint ring to a particular size selectably less than its final size, welding the joint ring to the end of the cylindrical pipe, and re-expanding the joint ring beyond its elastic limit to its final size.

Claim 5

A method of re-expanding a metal joint end of a cylindrical pipe with an expandable and contractable unitary C-ring having a continuous exterior cylindrical surface, wherein the steps comprise contracting the C-ring by applying an inward force thereto to reduce the normal diameter of the C-ring, mounting the C-ring within a cylindrical joint end, having already been initially expanded, of a cylindrical pipe with the axis of the C-ring axially aligned with the axis of the joint end and pipe, allowing the C-ring to expand toward its normal diameter thereby causing the exterior surface of the C-ring to engage the inner circumference of the joint end and distribute a substantially uniform radially outward force against the inner circumference of the joint end, and expanding the C-ring by a predetermined amount by applying outward force thereto to increase the C-ring to its normal diameter to thereby re-expand the joint end beyond its elastic limit to complete re-expansion of the joint end.

Claim 6

A method of re-expanding a metal joint end of a cylindrical pipe with an expandable and contractable unitary C-ring having a continuous exterior cylindrical surface, wherein the steps comprise contracting the C-ring by applying an inward force thereto to reduce the normal diameter of the C-ring, mounting the C-ring within a cylindrical joint end, having already been initially expanded, of a cylindrical pipe with the axis of the C-ring axially aligned with the axis of the joint end and pipe, allowing the C-ring to expand toward its normal diameter thereby causing the exterior surface of the C-ring to engage the inner circumference of the joint end and distribute a substantially uniform radially outward force against the inner circumference of the joint end, and expanding the C-ring by a predetermined amount by applying outward force thereto to increase the C-ring to its normal diameter to thereby re-expand the joint end beyond its elastic limit to complete re-expansion of the joint end.

Claim 7

A method of re-expanding a metal joint ring with an expandable and contractable unitary C-ring having a continuous exterior cylindrical surface, wherein the steps comprise contracting the C-ring by applying an inward force thereto to reduce the normal diameter of the C-ring, mounting the C-ring within a cylindrical joint ring, having already been initially expanded and welded to the end of a cylindrical pipe, with the axis of the C-ring axially aligned with the axis of the joint ring and pipe, allowing the C-ring to expand toward its normal diameter thereby causing the exterior surface of the C-ring to engage the inner circumference of the joint ring and distribute a substantially uniform radially outward force against the inner circumference of the joint ring, and expanding the C-ring by a predetermined amount by applying outward force thereto to increase the C-ring to its normal diameter to thereby re-expand the joint ring beyond its elastic limit to complete re-expansion of the joint ring.

Claim 8

A method of re-expanding a metal joint ring with an expandable and contractable unitary C-ring having a continuous exterior cylindrical surface, wherein the steps comprise contracting the C-ring by applying an inward force thereto to reduce the normal diameter of the C-ring, mounting the C-ring within a cylindrical joint ring, having already been initially expanded and welded to the end of a cylindrical pipe, with the axis of the C-ring axially aligned with the axis of the joint ring and pipe, allowing the C-ring to expand toward its normal diameter thereby causing the exterior surface of the C-ring to engage the inner circumference of the joint ring and distribute a substantially uniform radially outward force against the inner circumference of the joint ring, and expanding the C-ring by a predetermined amount by applying outward force thereto to increase the C-ring to its normal diameter to thereby re-expand the joint ring beyond its elastic limit to complete re-expansion of the joint ring.