×

Heat fusion fitting

  • US 6,585,924 B1
  • Filed: 03/31/2000
  • Issued: 07/01/2003
  • Est. Priority Date: 05/22/1997
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for the manufacture of a heat fusion fitting, which comprises:

  • i) forming a body of hollow, tubular construction comprising at least a first layer of a first cross-linked polymeric material, ii) forming an insert by moulding a second polymeric material around a ferromagnetic heating element so that the ferromagnetic heating element is embedded or partly embedded therein, the moulded material extending axially of the ferromagnetic heating element to form in-situ pre-moulded “

    cold zones”

    to contain the flow of melt from a melt region, the ferromagnetic heating element having a Curie temperature equal to or greater than the crystalline melting point or softening point of the second polymeric material, and iii) assembling the body and the insert to form the fitting by expanding the body at a temperature below the crystalline melting point or softening point of the first polymeric material to impart a degree of dimensional recoverability to the body, such that the body, or a portion thereof, can recover from a larger diameter to a smaller diameter and thereby engage the insert which is positioned in the direction of recovery.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×