Welding apparatus for welding an extension piece to a tube

Claim 2

An electric arc welding torch for welding an extension piece onto an open-ended tubular part comprising: a. a torch body, b. an electric arc welding head carried by said body and rotatable relative to said body, c. an electrode forming part of said head and arranged to be carried around the weld region during rotation of said head relative to said body to make a weld, d. means for supplying welding current to said electrode, e. arms extending from said body, f. means on said arms for releasably holding said extension piece aligned with said body, g. means for transferring said body and said extension piece while held together by said means on said arms to bring said extension piece into abutment with said tubular part, and h. a tapered guide carried by said body which tapers in the direction away from said body so that, as the body and extension piece are moved while held together, the guide progressively enters said open-ended tubular part, said guide being arranged to progressively center said body and extension piece until said guide centers said body and piece relative to said tubular part ready for welding said extension piece to said tubular body.

Claim 3

A torch according to claim 1 further comprising means for suspending said torch body from above so that, when said body is suspended from above said tapered guide is below said body.

Claim 4

A torch according to claim 2 in which said guide is heavy relative to said body so as to keep said torch relatively steady during welding.

Claim 5

A torch according to claim 1 in which said tapered guide has a shape chosen from a spherical cone shape, a truncated spherical cone shape and a conical shape.

Claim 6

A torch according to claim 1 in which said electrode has a tip and is outwardly directed relative to said body, said tip being within the radial size of the widest part of said tapered guide, whereby said torch is capable of effecting welding from inside said tubular part.

Claim 7

A torch according to claim 5 further comprising a spindle rotatably mounted within said torch body, said head being mounted on said spindlE, and means being provided for rotating said spindle relative to said body during the making of a weld.

Claim 8

A torch according to claim 1 further comprising magnets mounted on said arms for holding said extension piece against said arms.

Claim 9

An electric arc welding torch for welding an extension piece onto an open-ended tubular part comprising: a. a torch body, b. a spindle rotatably mounted in said body, c. a welding head mounted on said spindle so as to be rotatable relative to said body, d. means for rotating said spindle and said head relative to said body, e. a non-consumable electrode forming part of said head and arranged to be carried around the region of the weld by rotation of said head relative to said body during the making of a weld, f. means for supplying welding current to said electrode, g. means for supplying inert shielding gas to the region of said electrode to bracket said region of said weld during welding, h. a number of arms spaced around said body and extending radially away from said body, i. magnet means carried by said arms for holding said extension piece aligned with said body until after it has been welded to said tubular part, j. means to transfer said extension piece and body while held together by said magnet means to bring said extension piece into engagement with said tubular part, k. a spherical cone shaped guide mounted on said spindle, said guide being heavy relative to said torch body and being tapered from the base of said cone to the tip of said cone in the direction away from said body, the widest part of said cone being of substantially the same diameter as the inside diameter of said tubular part, and l. anti-friction means between said spindle and said guide so that said guide is free to rotate relative to said spindle, whereby when said body is moved to bring said guide into said tubular part at a point where said extension is aligned with said tubular part, said spindle can be rotated to weld said extension to said tubular part.

Claim 10

An electric arc welding torch for welding an extension piece onto an open-ended tubular part comprising: a. a torch body, b. a spindle rotatably mounted in said body, c. a welding head mounted on said spindle so as to be rotatable relative to said body, d. means for rotating said spindle and said head relative to said body, e. a non-consumable electrode forming part of said head and arranged to be carried around the region of the weld by rotation of said head relative to said body during the making of a weld, f. means for supplying welding current to said electrode, g. means for supplying inert shielding gas to the region of said electrode to bracket said region of said weld during welding, h. a number of arms spaced around said body and extending radially away from said body, i. magnet means carried by said arms for holding said extension piece aligned with said body until after it has been welded to said tubular part, j. means to transfer said extension piece and body while held together by said magnet means to bring said extension piece into engagement with said tubular part, k. a spherical cone shaped guide mounted on said spindle, said guide being heavy relative to said torch body and being tapered from the base of said cone to the tip of said cone in the direction away from said body, the widest part of said cone being of substantially the same diameter as the inside diameter of said tubular part, and l. anti-friction means between said spindle and said guide so that said guide is free to rotate relative to said spindle, whereby when said body is moved to bring said guide into said tubular part at a point where said extension is aligned with said tubular part, said spindle can be rotated to weld said extension to said tubular part.

Claim 11

A torch according to claim 8 in which said electrode has a tip and is outwardly directed relative to said body, said tip being within the radial size of the widest part of said tapered guide, whereby said torch is capable of effecting welds from inside said tubular part.