PURPOSE: To provide a heating plate in which heating wires do not short-circuit with each other even during energization with a pipe for welding.
CONSTITUTION: In a heating plate which is embedded in the inner surface of a joint and which is adapted to be used integrally incorporated with the joint, a spiral part in which a heating wire 2 is fitted and secured is formed on one side surface of the plate 1 made of thermoplastic resin, and the heating wire 2 is fixed thereto while pins 15, 16 are fixed to the outer periphery thereof, end parts of the heating wire 2 being connected to the pins 15, 16. Parts of the heating wire 2 in the vicinity of the ends thereof, are covered with insulation tubes 3, 4 which are not melted at the melting point of the plate 1.
KATO TAKESHI
NISHIKATA NOBUHIRO
| JP4110296B2 | 2008-07-02 | |||
| JPH04347094A | 1992-12-02 |