Method and apparatus of butt welding pipes or the like

• US 3,874,067 A
• Filed: 06/07/1973
• Issued: 04/01/1975
• Est. Priority Date: 06/07/1973
• Status: Expired due to Term

• Current Assignee: Kiyoshi Terai, Terumasa Toyooka
• Original Assignee: Kiyoshi Terai, Terumasa Toyooka
• Inventors: Terai, Kiyoshi, Toyooka, Terumasa
• Primary Examiner(s): Whitby, Edward G.
• Application Number:
  US05/367,928
• Time in Patent Office: 663 Days
• Field of Search: 156/73,544,580,304 29/470.3 228/1,2 264/68
• US Class Current: 228/112.1
• CPC Class Codes: B23K 20/129 specially adapted for particular articles or workpieces
• CPC Class Codes: B29C 65/0672 Spin welding
• CPC Class Codes: B29C 65/069 the welding tool cooperating with specially formed features of at least one of the parts to be joined, e.g. cooperating with holes or ribs of at least one of the parts to be joined
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/5221 for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
• CPC Class Codes: Y10T 156/1715 Means joining indefinite length work edge to edge

Abstract

The ends of two pipes or rods to be butt welded are beveled to form a V-shaped groove when abutting opening toward the outer periphery, a ring of metal of corresponding size and V-shaped configuration to the groove is positioned within the groove and the ring is forcibly rotated about the axis of the pipe or rod, while compressing the pipes or rods together. The heat of friction fully plasticizes the ends of the pipes or rods and the ring, rotation of the ring ceases and final compression between the pipes effects welding. Alternatively, the ends of the pipes are at right angles to the pipe axis and the ring comprises a short section of pipe corresponding to the two pipes to be butt welded.

Claims

1. A method of butt welding pipes comprising the steps of:

beveling the ends of the pipe to be butt welded to form opposed outwardly diverging surfaces, inserting a metal ring of corresponding size and thickness and having correspondingly oppositely diverging end surfaces between said pipes and in end abutting position with respect to said pipes to be joined, forcibly rotating the inserted ring about a common axis including the pipes and the ring while applying compressive force between the pipes and the ring to elevate the temperatures of the ends of the pipes and the ring by the heat of friction, terminating rotation of the ring, and applying final compression between the pipes to butt weld said pipes by means of said ring, with said ring being provided with a cross section corresponding to that of the diverging groove formed between the pipes when abutting;

whereby, fins resulting from welding do not form on the inner periphery of the welded pipe, and any fins formed by the wedge action of the beveled ends of the pipe acting on the insert ring are formed radially outward permitting subsequent removal from the exterior surface of the butt welded pipes.

2. An apparatus for butt welding at least one pair of end abutting pipes or the like, said apparatus comprising:

means for supporting at least two pipes in end to end coaxial position, means for supporting a metal ring having complementary end surfaces in contact with the ends of said respective pipes, means for applying compression between said pipes and said insert ring, means for selectively rotating said ring about a common axis between said pipe and said insert ring, said insert ring including gear teeth about its outer periphery, a gear ring internal and external gear teeth in mesh with said insert ring to effect rotation of said insert ring about the full periphery of the same by said intermeshed internal and external teeth of said gear ring and said insert ring respectively;

whereby, said insert ring is rotated to elevate the temperature of the pipe ends by said gear ring acting on the full periphery of said insert ring by the heat of friction developed by rotation of said insert ring to plasticize the same, rotation of the ring is terminated and final compression between said pipes welds the ends of the piPes together via said insert ring.

3. An apparatus for butt welding a plurality of pairs of axially positioned end to end pipes simultaneously, said apparatus comprising:

means for supporting said pairs of pipes in end to end coaxial position, means for supporting a metal insert ring having complementary end surfaces in contact with the ends of respective pipes of each pair, means for applying compression between said pipes of each pair and said insert ring, means for rotating said insert ring about a common axis between said pipes and said insert ring for each of said pairs of pipes, said means for rotating said insert ring comprising a plurality of ring gears each of which surrounds and is in mesh with an insert ring whose edges frictionally engage the ends of the pipes of said given pairs to be frictionally welded, said ring gears being in mesh with a driving gear at circumferentially spaced positions about said driving gear such that said means for rotating said driving gear simultaneously rotates the ring gears for each pair of pipes.