PURPOSE: To simplify a circuit construction, by a method wherein ceramic heating elements are fitted around a metallic core member provided in the interior of a steering wheel, and a current-passing circuit for the heating elements is constituted of each of the core members and a steering shaft.
CONSTITUTION: A wheel part 4, a central part 11 and spoke parts 5 of a steering wheel 2 are produced by molding a synthetic resin pellicle 3, 3a, 3b respectively around the metallic core members 2, 2a, 2b. The wheel part 4 is provided with a heating part 6 which comprises the heating elements 61, 61a provided around the core member 2, the inside surface 62 thereof is brought into contact with the core member 2, and the outside surface 63 thereof is brought into contact with an electrode plate 64. The heating elements 61, 61a have a positive resistance- temperature characteristic, and have a self-temperature-compensating function such that the electrical resistance thereof is rapidly increased at a specified temperature. An electrode part 65 provided at the inside surface of the heating element is connected to the negative pole of a power source 10 through the core members 2, 2a, 2b of the steering shaft 12, while the electrode plate 64 is connected to the positive pole of the power source 10 through a lead wire 7, a slip ring 8 and a switch 9.
KONDOU YASUO
IWASE AKIO
WATANABE MASAKANE
