Clamping apparatus for welding circumferential articles

• US 4,176,269 A
• Filed: 12/05/1977
• Issued: 11/27/1979
• Est. Priority Date: 02/03/1976
• Status: Expired due to Term

• Current Assignee: Cepi Holdings, Inc. (Stanley Black & Decker, Inc.)
• Original Assignee: Merrick Welding International Incorporated
• Inventors: Cook, George E., Modglin, Donald D., Merrick, George J.
• Primary Examiner(s): Reynolds, Bruce A.
• Assistant Examiner(s): Paschall
• Application Number:
  US05/857,226
• Time in Patent Office: 722 Days
• Field of Search: 219/60 A, 219/60 R, 219/59.1, 219/158-161, 219/121 R, 219/121 EM, 61/110, 61/111, 228/44.5, 269/45, 269/42, 269/43, 156/158, 65/152
• US Class Current: 219/60.00A
• CPC Class Codes: B23K 2101/06 Tubes
• CPC Class Codes: B23K 9/0286 with an electrode moving around the fixed tube during the welding operation
• CPC Class Codes: B23K 9/1093 Consumable electrode or filler wire preheat circuits
• CPC Class Codes: B23K 9/323 Combined coupling means, e.g. gas, electricity, water or the like electrical only H01R

Abstract

Apparatus for rapid and automatic welding of joints which interconnect sections of pipe, and in particular oil or gas transmission pipe. The system includes at least one torch transport assembly which simultaneously moves a plural number of welding torches along a path parallel to the pipe joint being welded. The torch transport assembly includes track segments which surround circumferential portions of the pipe joint, with a welding torch carrier and multiple torches being independently movable along each track segment. The torch transport assembly is mounted on a support apparatus which is rigidly clamped to the pipe sections during welding, and which permits the torch transport assembly to be rapidly positioned in rough alignment with a pipe joint. The torch transport assembly and selected operating parameters of each welding torch are adjusted to accurately position each torch with respect to the pipe joint, and to repeatably provide programmed welding parameters resulting in a uniform pipe joint weld. The present system is disclosed in the context of hot-wire gas-tungsten arc welding torches, and in the operating environment of out-of-position joint welding.

Claims

1. Apparatus for welding a circumferential joint interconnecting adjacent lengths of pipe which have an outer protective layer, comprising:

first means for selectably clamping onto said outer protective layer of said adjacent lengths of pipe so as to be supported by said pipe lengths while spanning said joint;

second means supported by said first means for a limited extent of movement in plural degrees of freedom relative to said first means to permit said second means to assume a certain alignment with a joint that may be angularly and axially misaligned relative to said outer protective layer on the pipe;

clamp means carried by said second means for clamping said second means to portions of said lengths of pipe lacking said protective layer and in fixed relation to said joint,

track means carried by said second means and defining a predetermined path of movement in proximate circumferential relation to said joint,

carriage means supported for movement about said track means; and

welding torch means carried by said carriage means in welding relation with said joint.

2. Apparatus as in claim 1, wherein said second means is supported on said first means by gimbal means which permits said second means to be positioned in said plural degrees of freedom for said proximate alignment of said track means with said joint while said first means remains securely clamped to said outer protective layer of said lengths of pipe.

3. Apparatus as in claim 1, wherein:

said clamp means comprises a pair of clamp arms each of which extends about a portion of the circumference of said pipe;

each of said clamp arms being selectably movable laterally of the length of said pipe, and each of said clamp arms having means to contact one of said lengths of pipe as said clamp arms are moved laterally inwardly toward said pipe; and

one of said clamp arms supporting said track means.

4. Apparatus as in claim 3, wherein said welding torch means is a first such means, and further comprising a second welding torch means carried by said carriage means in circumferentially offset relation to said first torch means.

5. Apparatus as in claim 1, wherein:

said clamp means comprises a first inner clamp means and a second inner clamp means longitudinally spaced apart from each other, so that one said clamp means may be positioned in clamping relation with a respective one of said adjacent lengths of pipe in proximity to said joint;

each of said inner clamp means having a pair of clamp arms each of which extends about a separate circumferential portion of the respective length of said pipe;

each of said clamp arms of each said inner clamp means being selectably movable laterally of the pipe length, and each of said clamp arms having means to contact the respective lengths of pipe as said clamp arms are moved laterally inwardly toward said pipe;

one of said clamp arms of said first inner clamp means supporting a first said track means which extends about a first circumferential portion of one of said lengths of pipe, and one of said clamp arms of said second inner clamp means supporting a second said track means which extends about a second circumferential portion of the other said length of pipe;

said carriage means is a first such means supported for movement about said first track means, and including a second carriage means supported for movement about said second track means; and

at least one said welding torch means carried by each of said carriage means in welding relation with said joint.

6. Apparatus as in claim 5, wherein at least one of said carriage means carries a plurality of said welding torch means in circumferentially offset relation to each other.

7. Apparatus as in claim 1, wherein:

said second means includes means which is supported for longitudinal movement along said pipe lengths relative to said first means and which carries said clamp means.

8. Apparatus as in claim 1, wherein:

said second means comprises support means selectably longitudinally movable relative to said first means so as to assume a predetermined position along said lengths of pipe relative to said joint;

means interconnecting said support means and said clamp means to permit said clamp means to rotate about an axis parallel to said pipe, to rotate about a horizontal axis perpendicular to said pipe, and to rotate about a vertical axis perpendicular to said pipe; and

means selectably operative to adjust the vertical spacing between said support means and said clamp means,

so that said clamp means can be moved relative to said first means so as to assume said predetermined alignment with said joint while said first means remains clamped onto the outer protective layer of the pipe.

9. Apparatus as in claim 1, wherein:

said first means comprises a pair of clamping assemblies mounted on opposite ends of a structure;

each of said clamping assemblies comprising a pair of clamping arms which have mutually opposed means for clamping onto said outer protective layer of a length of said pipe;

clamp actuating means separately mounting each pair of said clamping arms laterally of said length of pipe for selectable lateral movement either toward or away from clamping relation with said pipe; and

means operative to swing each paired clamping arm upwardly and away from said length of pipe when said clamping arms move a predetermined distance laterally away from the pipe, so that the entire said apparatus can be rapidly withdrawn from the proximity of the joint without interference from the pipe.

10. Apparatus as in claim 9, wherein said pair of clamping assemblies of said first means comprises an outer clamping assembly;

and wherein

said clamp means carried by said second means is an inner clamping assembly comprising a pair of clamping assemblies each of which has a pair of inner clamping arms;

means separately mounting each pair of said inner clamping arms for lateral movement either toward or away from said pipe portion which lacks said protective layer; and

means operative to swing each said inner clamping arm upwardly and away from said pipe portion when said inner clamping arms have moved a predetermined distance laterally away from the pipe joint.