Abstract: A steering wheel body 1 comprises sheaths 7a, 7b which covers a ring core bar 5 and spoke core bars 6A-6C, and a pad 3 formed integrally with the sheaths. A boss 8, 51, 28 is integral with the spoke core bars. A steering shaft 30 is formed at a distal end thereof with a serration 31 and an annular groove 32. The boss 8, 51, 28 includes a boss plate 33, a cylindrical portion 34, 74 with a serration 38, 68, 78, and a yoke portion 35 with through holes 36, 37, 66, 67, 76, 77. The cylindrical portion 34, 64, 74 is fitted on the end of the steering shaft 30 such that the serrations 31, 38, 68, 78 mesh with each other, and a bolt 41, 81, 91 is inserted and screwed into the through holes 36, 37, 66, 67, 76, 77. A collar 47 fitted on the bolt 41, 81, 91 is fitted in the annular groove 32. Strain stress is never transmitted directly to the bolt 41, 81, 91.

Abstract: A ceramic sintered body fitted into an inner hole through a cylindrical metal outer pipe in the state in which the front end side of the ceramic sintered body is protruded out from the front end of an metal shell, includes: a heating portion to which a positive-pole-side lead is connected in the front end side; and a positive-pole-side electrode lead-out portion having a positive-pole-side electrode portion which is extendedly provided from the positive-pole-side lead in the rear end side. Further, the outer diameter of the positive-pole-side electrode lead-out portion is set to be smaller than that of the negative-pole-side electrode lead-out portion so that the positive-pole-side lead is substantially linear and a sufficient insulation distance between the metal shell functioning as a negative-pole-side terminal and the positive-pole-side lead coil can be secured.

Abstract: An igniter plug comprising: a metallic shell having a diameter-reduced seat at one open end, the seat being tapered to progressively decrease its diameter as approaching at outside of the open end; a tubular insulator concentrically placed at an inner side of the metallic shell, and having a tapered end face to be in registration with the seat; a frusto-cone shaped insert ring made of oxidation and heat resistant material, a peripheral end and one entire surface of which are mounted on a surface of the seat by means of an electrical resistant welding, the insert ring permitting the tapered end face of the insulator to engage with an upper surface of the insert ring; a center electrode concentrically disposed in the insulator, one end of the electrode being terminated short of the tapered end face to allow a creeping discharge to occur along an inner surface of the insulator when a high voltage is applied across the electrode and the insert ring.