To suppress a faint vibration in a yoke itself, and prevent the yoke from resonating for prevention of unpleasant noise by mounting a vibration-proof material formed out of roughly circumferential-shaped elastic resin or rubber which is brought into close contact with the opening-side peripheral surface in a yoke side surface, and a metallic C ring pressing the vibration-proof material against the yoke on the inner peripheral surface of the vibration-proof material.
A yoke housing 4 has an opening in one end, and a cylindrical from having a bottom on the other end. A strip rubber sheet 8 is fixed as a vibration-proof material on the inner wall opening end side of the yoke 4, and a metallic C ring 9 is compressed and mounted therein. The instantaneous faint vibration of the vibration of the yoke 4 is absorbed by the cushion action of a vibration-proof material 8. The metallic C ring 9 mounted on the inner peripheral surface of the vibration-proof material 8 presses the vibration-proof material 8 against the yoke 4, the adhesion of the yoke 4 and the vibration-proof material 8 increases for improvement to vibration isolating effect. The metallic C ring 9 itself prevents such deformation that the opening side of the yoke 4 is narrowed, so that periodic large vibration is absorbed.
SAKAMOTO WATARU
KUWANO MASAYUKI
