Plastic pipe welding apparatus and method

• US 4,132,578 A
• Filed: 10/15/1976
• Issued: 01/02/1979
• Est. Priority Date: 10/15/1976
• Status: Expired due to Term

• Current Assignee: Harold A. Gell, Jr.
• Original Assignee: Harold A. Gell, Jr.
• Inventors: Gell, Harold A. Jr.
• Primary Examiner(s): Powell, William A.
• Assistant Examiner(s): Gallagher, J. J.
• Application Number:
  US05/732,984
• Time in Patent Office: 809 Days
• Field of Search: 156/156, 156/294, 156/158, 156/304, 156/289, 156/306, 156/296, 156/583, 428/36, 264/248, 285/284, 285/423, 285/286, 285/DIG. 20, 285/21, 219/228, 73/363.5, 73/363.7
• US Class Current: 156/158
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/24 characterised by the means for heating the tool by impulse heating B29C65/38
• CPC Class Codes: B29C 65/245 the heat transfer being achieved contactless, e.g. by radiation B29C65/32 takes precedence
• CPC Class Codes: B29C 65/26 Hot fluid
• CPC Class Codes: B29C 65/28 Flame or combustible material
• CPC Class Codes: B29C 65/30 Electrical means B29C65/38 takes precedence
• CPC Class Codes: B29C 65/32 Induction
• CPC Class Codes: B29C 66/00461 being liquid, e.g. oil based
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• 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: B29C 66/52292 said stop being internal
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/81261 Thermal properties, e.g. thermal conductivity, thermal expansion coefficient
• CPC Class Codes: B29C 66/81471 being a wrap-around tape or band
• CPC Class Codes: B29C 66/8414 of different diameter
• CPC Class Codes: B29C 66/861 Hand-held tools
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: F16L 47/02 Welded joints; Adhesive joints
• CPC Class Codes: Y10S 285/919 Resinous
• CPC Class Codes: Y10T 428/1355 Elemental metal containing [e.g., substrate, foil, film, coating, etc.]

Abstract

A method and apparatus for welding PVC pipe which includes a means to clamp and apply welding heat so that plastic pipes may be welded while under external pressure adapted to offset internal pressures. The method includes the steps of placing a clamp about a splice to be welded, tightening the clamp and applying heat through the clamp to the plastic in sufficient quantities to cause the plastic to fuse. The steps are carried out by utilizing an apparatus comprised of a clamp which is adapted to encompass the area to be welded and apply a constricting force to that area while heat is transferred through the clamping means to the plastic.

Claims

1. A method of welding a plastic pipe which includes the steps of:

bringing together two separate pieces of plastic pipe to be welded to form a splice;

placing a bimetallic clamp about said splice; and

applying heat to said bimetallic clamp in sufficient quantities to cause said bimetallic clamp to tighten about said splice and to cause the plastic thereunder to fuse.

2. A method as described in claim 1 including the additional step of:

applying a release agent to the inner surface of said bimetallic clamp before applying said bimetallic said splice clamp to.

3. A method as defined in claim 1 further including the step of applying a plastic filler rod to the plastic pipe to be welded prior to applying said bimetallic clamp.