Apparatus and method for fusion joining a pipe and fittings

• US 6,193,834 B1
• Filed: 04/23/1999
• Issued: 02/27/2001
• Est. Priority Date: 01/24/1996
• Status: Expired due to Fees

• Current Assignee: Uponor Aldyl Co. (J-M Manufacturing Company)
• Original Assignee: Uponor Aldyl Co. (J-M Manufacturing Company)
• Inventors: Smith, Cin Lee
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Tolin, Michael A
• Application Number:
  US09/117,237
• Time in Patent Office: 676 Days
• Field of Search: 156/272.4, 156/273.9, 156/274.2, 156/274.4, 156/274.8, 156/275.1, 156/275.3, 156/275.7, 156/293, 156/294, 156/304.2, 156/304.3, 156/304.5, 156/308.4, 156/309.6, 219/607, 219/633, 219/634, 219/643, 219/535, 219/544, 285/21.2, 285/286.1, 285/286.2, 285/294.1, 285/921, 285/319
• US Class Current: 156/273.9
• CPC Class Codes: B29C 65/3612 comprising fillers
• CPC Class Codes: B29C 65/362 comprising at least a single wire, e.g. in the form of a winding
• CPC Class Codes: B29C 65/364 being a woven or non-woven fabric or being a mesh
• CPC Class Codes: B29C 65/3644 being a ribbon, band or strip
• CPC Class Codes: B29C 65/3668 characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils
• CPC Class Codes: B29C 65/368 with a polymer coating
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• 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 66/52241 with two right angles, e.g. for making T-shaped pieces
• CPC Class Codes: B29C 66/52292 said stop being internal
• CPC Class Codes: B29C 66/52297 said socket comprising slip-off prevention means B29C66/52296 takes precedence
• CPC Class Codes: B29C 66/52298 said socket being composed by several elements
• CPC Class Codes: B29C 66/80 General aspects of machine operations or constructions and parts thereof
• CPC Class Codes: F16L 47/02 Welded joints; Adhesive joints
• CPC Class Codes: Y10S 285/921 Snap-fit

Abstract

An apparatus for fusing a pipe to a fitting includes an induction heating element wholly encased or coated with a flusible thermoplastic polymeric material, a fitting having a socket or a flange. The induction heating element is adapted to be inserted into said socket or mounted on said flange, the fitting and the element together defining a throughbore, a portion of a pipe adapted to be inserted into the throughbore or mountable on said flange. The apparatus also includes a locating and maintaining member on the induction heating element with one or more projections adapted to be snap-fitted on the fitting, the pipe or both, and capable of locating and maintaining the position of the heating element relative to the fitting or the member portion. The induction fusion element is capable of fusing the fitting and the pipe portion.

Claims

1. A method for fusing a pipe to a fitting, comprising:

inserting an induction heating element within a socket of a fitting or mounting the induction heating element on a flange of the fitting, the fitting and the element together defining a throughbore,

inserting a portion of the pipe into the throughbore or mounting a portion of the pipe on said flange,

locating and maintaining the heating element in or on the fitting or pipe respectively by one or more snapfit projections on the fitting, the pipe or both, and

energizing the induction fusion element.

2. The method of claim 1 further comprising removing an external layer of material at the pipe and induction heating element interface prior to contact.

3. An apparatus for fusing a pipe to a fitting, comprising:

an induction heating element wholly encased or coated with a fusible thermoplastic polymeric material,

fitting having a socket or a flange, wherein the induction heating element is adapted to be inserted into said socket or mounted on said flange, the fitting and the element together defining a throughbore,

a portion of a pipe adapted to be inserted into the throughbore or mountable on said flange; and

,

a locating and maintaining member on the induction heating element comprising one or more projections adapted to be snap-fitted on the fitting, the pipe or both, and capable of locating and maintaining the position of the heating element relative to the fitting or the pipe portion,

wherein the induction fusion element is capable of fusing the fitting and the pipe portion.

4. The apparatus of claim 3 wherein said induction heating element comprises a sleeve.

5. The apparatus of claim 3 wherein said induction heating element comprises a cylindrical mat.

6. The apparatus of claim 3 wherein said induction heating element comprises pre-formed conductive wire.

7. The apparatus of claim 3 wherein said induction heating element comprises a polymeric body carrying conductive particles.

8. The apparatus of claim 4 wherein the fitting includes stop means for limiting longitudinal insertion of said induction heating sleeve element within said fitting.

9. The apparatus of claim 3 wherein the fitting further comprises stop means for limiting longitudinal insertion of said pipe portion into said throughbore.

10. The apparatus of claim 9 wherein said stop means comprises an internal collet located on an internal surface of said induction heating element.

11. The apparatus of claim 3 wherein the induction heating element includes substantially non-conducting plastics material forming cold zones to contain the melt during the fusion step.

12. The apparatus of claim 11 wherein said non-conducting plastics material is molded with the fusible thermoplastic polymeric material.

13. The apparatus of claim 3 wherein said heating element comprises an induction heating cage in series with an induction loop externally mounted on said fitting.

14. The apparatus of claim 13 wherein the heating cage is flat.

15. The apparatus of claim 14 further comprising snap-fit projections formed on the heating element.