1. Field of the Invention
The present invention relates to an automobile wheel cover, and more particularly, to a wheel cover, wherein, when the wheel cover is fixed to a wheel, a plurality of holding claws protruding from the rear surface of the wheel cover are urged toward a rim of a wheel by means of a resilient ring in the radially outward direction.
2. Prior Art
Conventional wheel covers have a variety of constructions: for example, a wheel cover as shown in FIGS. 1 and 2 is described in Japanese first patent publication Ser. No. 67602/1981. Referring to FIGS. 1 and 2, a plurality of holding claws 22 are formed on the rear surface of the wheel cover main body 21, a groove 22a is formed on the radially inside surface of each holding claw 22, and a base portion 23b of an arch-shaped protrusion 23a of the wire ring 23 is pressed to contact with stoppers 24 which is formed at both sides of the holding claw 22 so as to protrude from the rear surface of the wheel cover main body, whereby the radially outwardly spreading force of the wire ring 23 is received by means of the stoppers 24. When holding claws 22 are radially inwardly bent during a mounting operation of the wheel cover onto the wheel, the protrusion 23a of the wire ring 23 is also bent, thereby applying resilient force of the wire ring 23 as well as the resilient force of the holding claw, thus a great resilient force is applied to the holding claw 22 even by a slight degree of bending of the holding claw 22. In the construction described above, when fitting the wheel cover to the wheel, some holding claws 22 of the wheel cover 21 are first bent toward the central portion of the wheel cover so as to abut on the wheel rim, then the rest of the holding claws are gradually bent toward the central portion so as to fit the entire wheel cover to the wheel rim, whereby holding claws 22 are pressed to contact with the wheel rim with the aid of the foregoing resilient force in order to fit the wheel cover 21 to the wheel.
For another construction of a conventional wheel cover as shown in FIG. 3 is described in Japanese first patent publication Ser. No. 67601/1981. The wheel cover in FIG. 3 has basically the same construction as the one described above; however its construction of the wire ring is altered, i.e., as shown in FIG. 3, a ratio of a radial dimension R from the center of the wire ring 27 to a protrusion 27a and a radial dimension r from the foregoing center to a base portion 27b of the protrusion 27a, is properly set, whereby, as shown by a dotted line in the drawing, when the protrusion 27a is bent inwardly toward the central portion with the aid of the holding claw, the base portion 27b is also bent in the same direction together with the holding claw. Thus the protrusion 27a of the wire ring 27 is provided with a large stroke so as to resist the resilient force of the wire ring and the foregoing holding claw by means of utilizing a large vacant space located inside the wheel rim.
According to the constructions described above, however, the wire ring is provided with a multiplicity of protrusions, whereby the number of shaping procedures for shaping the protrusions becomes large, increasing the production cost to a great extent. When the number of protrusions of the wire ring is reduced in order to lower the cost for the wire ring, the number of holding claws corresponding to the protrusions is also reduced, resulting in the increased holding force applied on the wheel rim exerted by each holding claw, whereby the bending degree of each holding claw is accordingly increased such that it is difficult for the wheel cover to be fitted in the wheel. Furthermore, there is provided no regulating means for bending the wire ring in the radially inside portion of the wire ring, causing the wire ring to freely bend, whereby the wire ring is apt to be removed from the holding claw.