US 12,459,212 B2
Electrofusion joint and fusion method
Ayaka Kitagawa, Kyoto (JP); Amiko Sakamoto, Kyoto (JP); Hiroaki Kondou, Kyoto (JP); Kouzou Makino, Kyoto (JP); and Tsuyoshi Katou, Kyoto (JP)
Assigned to SEKISUI CHEMICAL CO., LTD., Osaka (JP)
Appl. No. 17/794,068
Filed by SEKISUI CHEMICAL CO., LTD., Osaka (JP)
PCT Filed Jan. 25, 2021, PCT No. PCT/JP2021/002489
§ 371(c)(1), (2) Date Jul. 20, 2022,
PCT Pub. No. WO2021/149832, PCT Pub. Date Jul. 29, 2021.
Claims priority of application No. 2020-010025 (JP), filed on Jan. 24, 2020; application No. 2020-219395 (JP), filed on Dec. 28, 2020; and application No. 2020-219396 (JP), filed on Dec. 28, 2020.
Prior Publication US 2023/0065732 A1, Mar. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. B29C 65/00 (2006.01); B29C 65/34 (2006.01)
CPC B29C 65/3432 (2013.01) [B29C 65/3468 (2013.01); B29C 65/348 (2013.01); B29C 66/5221 (2013.01); B29C 66/71 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An electrofusion joint comprising:
a main body having a tubular shape and including a joint receiving portion for receiving a pipe containing a thermoplastic resin;
a stopper portion projecting inwardly on an inner surface of the main body, the stopper portion being configured to regulate an insertion position of an end of the pipe when the pipe is inserted inside the joint receiving portion;
a first heat generation section including a first heater wire that is wound and arranged in the joint receiving portion; and
a second heat generation section including a second heater wire that is wound so that wound parts of the second heater wire are adjacent to each other along a second axis parallel to a central axis of the main body, the second heater wire being in the stopper portion,
wherein the first heat generation section includes at least one heat generation portion in which the first heater wire is wound so that wound parts of the first heater wire are adjacent to each other along a first axis parallel to the central axis of the main body, and a number of adjacent turns of the second heater wire along the second axis is larger than a number of adjacent turns of the first heater wire along the first axis in the at least one heat generation portion adjacent to the second heat generation section.