Method of welding the ends of pipe together using dual welding wires
First Claim
1. A method of welding the end of a first pipe to the end of a second pipe by use of a welding bug having a welding wire feeder capable of feeding two welding wires simultaneously at the same speed and means for driving the bug along a track on the outside periphery of pipe which comprises:
- continuously moving said bug along said track;
applying the initial welding pass to the adjacent ends of said first and second pipe from outside said first and second pipe without use of internal line-up clamps with back-up shoes and using dual welding wires to form a puddle between the ends of the pipe;
during said initial pass varying the speed of said welding bug without regard to the angular position of the welding head and without stopping it while it is continuously moving about said track on said pipe to maintain the ends of the welding wires at a desired position with respect to the welding puddle.
3 Assignments
0 Petitions
Accused Products
Abstract
A new system for welding sections of pipe together to form a long, continuous pipeline. A welding bug is mounted on a guide track which goes around the circumference of the pipe. The welding bug is provided with a wire feeder, a motor to drive the wire feeder, and driving motor for driving the bug around the track. One may vary the speed of the bug and the wire feeder while the bug is continuously driven around the track. The welding head on the welding bug is powered by a surface-tension-transfer power source. The initial or root pass is made external of the pipe. In one embodiment there is a dual welding wire feeder for driving two welding wires simultaneously at the same speed.
86 Citations
78 Claims
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1. A method of welding the end of a first pipe to the end of a second pipe by use of a welding bug having a welding wire feeder capable of feeding two welding wires simultaneously at the same speed and means for driving the bug along a track on the outside periphery of pipe which comprises:
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continuously moving said bug along said track; applying the initial welding pass to the adjacent ends of said first and second pipe from outside said first and second pipe without use of internal line-up clamps with back-up shoes and using dual welding wires to form a puddle between the ends of the pipe; during said initial pass varying the speed of said welding bug without regard to the angular position of the welding head and without stopping it while it is continuously moving about said track on said pipe to maintain the ends of the welding wires at a desired position with respect to the welding puddle. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus for welding one end of a first pipe to a first end of a second pipe which comprises:
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a welding tractor; a power generator on and powered by said tractor; a surface-tension-transfer (STT) power source connected to said power generator; a welding bug including a dual wire feeder, a welding head, and means to guide said bug around the periphery of said pipe; connection means for connecting the welding head of said bug to said STT power source; manual speed control means, independent of any angular position of the welding bug, for remotely varying the speed of said welding bug as it moves about said track on said pipe. - View Dependent Claims (8)
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9. A method of welding the end of a first pipe to the end of a second pipe by use of a welding bug having a welding wire feeder for supplying two welding wires and means for driving the bug along a track on the outside periphery of pipe which comprises:
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positioning the ends of the first and second pipe in close proximity to one another to have an unobstructed gap therebetween; continuously moving said bug along said track; applying the initial welding pass to the adjacent ends of said first and second pipe from outside said first and second pipe while simultaneously driving two welding wires with one wire directed at the end of the first pipe and the second welding wire directed to the second pipe; varying the speed of said welding bug without stopping it while it is continuously moving about said track on said pipe to maintain a desired position of the welding wires with the welding puddle; when applying the initial welding pass using power from a surface-tension-transfer power source.
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10. A method of welding a first pipe to the end of a second pipe by use of a welding bug having a welding wire feeder feeding two welding wires and means for driving the bug along a track on the outside periphery of said pipe which comprises:
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connecting the welding bug to a STT power source, continuously moving said bug along said track, applying the initial welding pass to the adjacent ends of said first and second pipe from outside said first and second pipe, observing the end of the welding wire in relation to the welding puddle, varying the speed of said welding bug without stopping it while it is continuously moving about said track on said pipe to keep the ends of the welding wire just ahead of the puddle. - View Dependent Claims (11)
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12. An apparatus for welding one end of a first pipe to a first end of a second pipe which comprises:
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a welding tractor; a power generator on and powered by said tractor; a surface tension transfer (STT) power source connected to said power generator; a welding bug including a dual welding wire feeder, including a wire feeder motor and in which both welding wires are driven by the same wire feeder motor, a welding head, and means to guide said bug around the periphery of said pipe; connecting means for connecting the welding head of said bug to said STT power source such that each welding wire is connected to the same STT power source; speed control means for remotely varying the speed of said welding bug as it moves about said tracks on said pipe; means for varying the rate at which said wire is fed from said wire feeder.
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13. A method of welding the end of a first workpiece to the end of a second workpiece by use of a welding bug having a welding wire feeder and a mechanism to drive the welding bug along a track on the outside periphery of workpiece which comprises:
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a. continuously moving said bug along said track during said welding; b. applying the initial welding pass to the adjacent ends of said first and second workpiece from outside said first and second workpiece and using a welding wire fed to said workpiece to form a puddle between the ends of the workpiece; and c. during said initial pass varying the speed of said welding bug or the feed rate of said welding wire without stopping said welding bug while said welding bug is continuously moving about said track on said workpiece to maintain the end of the welding wire ahead of the welding puddle. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. An apparatus for welding one end of a first workpiece to a first end of a second workpiece which comprises:
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a. a welding tractor; b. a power generator on and powered by said tractor; c. a surface-tension-transfer (STT) power source connected to said power generator; d. a welding bug including a wire feeder, a welding head, and a mechanism to guide said welding bug around the periphery of said workpiece; e. a connector to connect the welding head of said bug to said STT power source; and f. a speed controller to continuously move the welding bug about said track on said workpiece during the formation of the weld, said speed controller controlling the speed of said welding bug during said weld formation. - View Dependent Claims (49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74)
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75. A dual welding wire feeder to drive a first welding wire and a second welding wire for use in welding comprising:
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an end feeder wire portion having a set of teeth; an outer end feeder wire portion having a set of teeth; a middle wire feeder portion positioned between said end feeder wire portion and said other end feeder wire portion, said middle wire feeder portion having two sets of teeth; a drive hub having a wire feeder portion engagement surface that is telescopically received in said end feeder wire portion, said outer end feeder wire portion and said middle wire feeder portion, said engagement surface having a non-circular cross-sectional shape; said first welding wire positioned between said end feeder wire portion and said middle wire feeder portion and said second welding wire positioned between said other end feeder wire portion and said middle wire feeder portion; and a drive source connected to said drive hub to simultaneously drive said end feeder wire portion, said outer end feeder wire portion and said middle wire feeder portion such that said first welding wire and said second welding wire are simultaneously driven. - View Dependent Claims (76, 77)
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78. A method of welding the end of a first workpiece to the end of a second workpiece by use of a welding bug having a dual welding wire feeder for a first and a second welding wire and a mechanism to drive the welding bug along a track on the outside periphery of the workpiece, which comprises:
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continuously moving said welding bug along said track; connecting the welding bug to a STT power source; and applying the initial welding pass to the adjacent ends of said first and second workpiece from outside said first and second workpiece using two welding wires to form a puddle between the ends of said workpiece and positioning the end of one wire at least closely adjacent the end of the first workpiece and positioning the end of the second welding wire at least closely adjacent the end of the second workpiece.
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Specification