US 12,259,076 B2
Electrofusion joint
Ayaka Kitagawa, Kyoto (JP); Hiroaki Kondou, Kyoto (JP); and Kouzou Makino, Kyoto (JP)
Assigned to SEKISUI CHEMICAL CO., LTD., Osaka (JP)
Appl. No. 17/764,722
Filed by SEKISUI CHEMICAL CO., LTD., Osaka (JP)
PCT Filed Sep. 28, 2020, PCT No. PCT/JP2020/036567
§ 371(c)(1), (2) Date Mar. 29, 2022,
PCT Pub. No. WO2021/065776, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 2019-179793 (JP), filed on Sep. 30, 2019.
Prior Publication US 2022/0341528 A1, Oct. 27, 2022
Int. Cl. F16L 47/03 (2006.01); B29C 65/34 (2006.01); B29K 101/12 (2006.01); B29L 31/24 (2006.01)
CPC F16L 47/03 (2013.01) [B29C 65/3432 (2013.01); B29K 2101/12 (2013.01); B29L 2031/24 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An electrofusion joint, comprising:
a main body configured to be connected to a resin pipe containing a thermoplastic resin; and
a heating wire,
wherein:
the heating wire includes a conducting wire, an insulating cover film in an annular shape around the conducting wire, and an outer layer portion in an annular shape around the insulating cover film;
the insulating cover film has a melting point of at least 230° C.; and
the outer layer portion is made of a polyolefin-based resin;
the main body includes:
a tubular portion having a connecting portion configured to: (i) be disposed inside or outside the resin pipe; (ii) be connected to the resin pipe; and (iii) receive the resin pipe; and
a stopper protruding from an inner surface of the tubular portion, the stopper being configured to restrict an insertion position of an end of the resin pipe when the resin pipe is inserted into the connecting portion;
the stopper is configured to protrude radially inward less than an inner peripheral surface of the resin pipe when the resin pipe is inserted into the connecting portion;
the heating wire is in the stopper;
the heating wire is wound three or more times along an axial direction of the tubular portion in the stopper; and
the heating wire is wound around the stopper in a single spiral shape.