GB2158016A - Wheel cover assembly - Google Patents

Abstract

A plastics moulded automobile wheel cover assembly comprises a vacuum-formed fascia moulding 1 carrying visual design features on its main surface and an injection moulded mounting ring 2 comprising an out-turned flange 17. A peripheral portion of the fascia moulding 1 is interfacially secured to the flange 17 by seven ultrasonic spot welds or by adhesive spaced at intervals around a pitch circle. In use, portion 16 of moulding 2 is received in the well 22 of wheel 21. Clips 20 received in pockets 18 moulded as detail on the portion 16 flex radially inwardly as the wheel cover is urged into well 22 and the clips engage against well surface 23 to retain the wheel cover in position to prevent dislodgement with wheel motion. <IMAGE>

Description

SPECIFICATION Wheel cover assembly The invention relates to a wheel cover assembly and is particularly, but not exclusively, concerned with a plastics moulded automobile wheel cover assembly.

Wheel covers are in wide use as an auto accessory to provide aesthetic appeal to otherwise unappealing pressed steel wheels and in most mass produced forms, wheel covers are made of plastics material.

Standard designs comprise a visually appealing fascia and an integral cylindrical mounting ring for reception in the well of a pressed steel wheel. The mounting ring is moulded with fixing or mounting means for use in securing the cover to a wheel. For example, the mounting ring moulding may be formed with pockets each of which receives a sprung metal clip which engages a circumferential well surface. This need for moulding detail has meant that injection moulding is the standard moulding technique employed in manufacture of plastics wheel covers.

Injection moulding involves heavy financial investment in tooling, particularly where a complete range of different fascia designs is involved. This investment is subject to risk whilst market reaction to the designs is under test. Nevertheless, injection moulding continues to be used as the standard production method for plastics wheel covers and has been for a large number of years.

According to the invention, a wheel cover assembly comprises a pressure moulded (e.g. vacuumformed) exterior member for exposure as a fascia and at least one injection moulded interior member secured to the exterior member and moulded with integral mounting or fixing means for use in securing the cover assembly to a wheel.

The wheel cover of the invention will normally comprise an interior member comprising an annular flange defining a hollow, right, circular cylinder which in use is received co-axially in the well of, for example, a pressed steel wheel. A flange defining part only of such a cylinder may serve as interior member. However, a single such flange will in practice need to be sufficiently co-extensive with a circumferential mating surface of the wheel to provide effective security of mounting to the wheel in use. A flange having 270 of arc may be satisfactory. Two or more flanges cooperative to provide the desired mounting security are an alternative, for example three flanges spaced equally one from another on the circumference of an imaginary right circular cylinder.A plurality of flanges when present may be secured directly to the exterior member but preferably originate from a common base element forming part of a single interior mounting member (e.g. a circular or annular base element).

The interior member mounting means in any of the forms of interior member referred to may comprise moulded retaining means for clip elements which in use engage the wheel to which the cover assembly is fitted. The clip elements may, for example, each comprise resilient members (usually of metallic material) retained by the retaining means and urged against their resilience into contact (e.g.

impingement) with a wheel surface. The retaining means may conveniently locate such a resilient member in a slideway in which the resilient member is retained against inadvertent dislodgement, for example the urging of the member into contact with the wheel surface serving to increase retention of the member in the slideway.

The or each interior member is preferably secured to a surface of the exterior member which is not exposed when the cover assembly is fitted to a wheel.

Both the exterior and the interior members are usually made of a plastics material, and their securement together is normally acco n polished by ultrasonic welding. For example, six or seven spot welds disposed at equispaced points on a pitch circle have been found to be effective to secure an interior member annulus to the fascia. The use of an adhesive or solvent welding (e.g. using ABS dissolved in a solvent such as methyl ethyl ketone) are alternative means of securing the interior and exterior members together. Suitable adhesives are cyanoacrylate adhesives.

The exterior member will normally be made by vacuum-forming and may be made of any of a variety of thermoplastic and thermosetting plastics materials. Preferred thermoplastic materials for the or each interior member include acrylonitrilebutadiene-styrene copolymer resin (ABS) and polystyrene (usually high impact polystyrene). Acetal polymer is one alternative. The interior and exterior members are preferably made of the same plastics material in order to facilitate ultrasonic welding. ABS is the preferred material, and in the case of the exterior member a high gloss finish is preferably provided on the exposed face of the moulded fascia, for example by using blanks made of acrylic-coated ABS sheet. For this reason, the exterior member is preferably made from a positive mould.

The exterior member may be formed with any of a variety of visual design features.

The following description is intended to illustrate the invention, by way of example only, reference being made to the accompanying drawings in which: Figure 1 is an exploded view of an assembly according to the invention in combination with an automatic wheel disposed to receive the assembly, the fascia moulding being shown in simplified form; Figure 2 is a cross-section taken along the line ll-ll of Figure 1, with the components shown exploded apart in Figure 1 brought together as an assembly; Figure 3 is a cross-sectional view showing, in greater detail and on an enlarged scale, the portion of Figure 2 encircled by broken line Ill; Figure 4 is a partial plan view of the assembly shown in Figures 1 and 2 showing visual design features of the fascia; Figure 5 is a plan view of a positive moulding tool for use in vacuum-forming the fascia shown in Figure 4;; and Figure 6 is a cross-section, on an enlarged scale, of the tool shown in Figure 5 taken along the line VI-VI of Figure 5.

The wheel cover assembly shown in Figures 1 and 2 comprises a circularvacuum-formed fascia moulding 1 and an injection moulded mounting ring 2, the two being secured together by seven ultrasonic or adhesive spot welds 3 spaced apart at equal intervals on a pitch circle. More or less welds or solvent deposits may be used or the adhesive could be applied in strips or a continuous annular deposit.

Fascia moulding 1 is made from acrylic resin-faced sheet ABS resin blanks 0.06in (approx. 1.5mm) thick, the acrylic resin facing imparting a high gloss finish to the exposed face 4 of the moulding.

Exposed face 4 has an essentially flat annular peripheral portion 5 encircling a generally convex circular main face 6. A downturned marginal edge of peripheral portion 5 forms a cylindrical flange 7.

Three identical recesses 8 (Figure 4) are formed in the main face 6 as a visual design features, recesses 8 being disposed at 120 centres on a pitch circle.

Each recess 8 has a depression 9 and an opening 15, a curved sloping shoulder 11 forming a junction between the two. Each depression 9 is formed with a generally flat floor 12 relieved by four concentric rectangular sectioned decorative channels 13. Opening 15 is defined between walls 14 which are essentially perpendicular to depression floor 12.

Mounting ring 2 is also made of ABS resin, and comprises a cylinder 16 of non-uniform circular cross-section and an out-turned flange 17.

Mounting ring 2 is injection moulded in a single shot with twelve pockets 18 on its outer circumference. Each of pockets 18 has a pair of opposed slots 19 for receiving a resilient clip 20, in generai half only of the pocket 18 being so used. A U-shaped opening (not shown in cylinder 16 accomodates the valve body of a pneumatic tyre when the cover assembly is mounted to the wheel 21.

Flange 17 mates with the undersurface of peripheral portion 5 of fascia moulding 1, welds 3 securing the two together in face-to-face contact.

As will be seen from Figure 1, the cover assembly can be mounted to the wheel 21 by offering up the assembly to the well 22 of the wheel and inserting the cylinder 16 into the well. In so doing, the clips 20 contact the circumferential well surface 23, the clips being flexed radially inwardly against their resilience so that their tips are urged against the surface 23.

This retains the cover assembly firmly in position on the wheel 21 and prevents dislodgement with wheel motion.

The moulding tool shown in Figures 5 and 6 comprises a solid ducted aluminium body 24 configured with appropriate surfaces to form the fascia moulding 1 shown in Figure 4. The mould features of the tool are designated in Figures 5 and 6 by reference numerals the same as those designating the corresponding fascia features but supplemented by the letter "a".

Air exhaust ducts 25 penetrate the body 24 around a pitch circle on mould surface 5a, at the base of channels 13a and adjacent the walls 14a. Each duct is connected to a remote source of moulding vacuum (not shown).

The plastics sheet material drawn onto raised surface 15a and over its edges is removed, after vacuum-forming, by perforation of the sheet at the bases of vertical walls 14a.

The invention as described earlier without reference to the drawings may include any one or more features of the invention as described with reference to the drawings.

In its broad sense, it will accordingly be appreciated that wheel covers of the invention comprise two components; a first member having a surface for exposure as a fascia when the cover is mounted to a vehicle wheel, the said surface normally carrying features of visual design, and a second member which cooperates with a vehicle wheel to mount the cover thereto. The two components are secured together, usually by means of an adhesive (or possibly by solvent or plasticizer welds) which may conventiently be disposed in a plurality of spaced apart dabs or other deposits. The first (fascia) member is made by pressure-forming (e.g. vacuumforming); the second (mounting) member is normally made by injection moulding. The invention includes within its scope the combination of the two above-mentioned moulding operations with a step of uniting the two moulded components together, e.g. by use of a cyanoacrylate or other adhesive.

Claims (8)

1. Awheel cover assembly comprising an exterior member for exposure as a fascia and formed by vacuum-forming oranotherform of pressure moulding, and at least one injection moulded interior member secured by adhesive or otherwise to the exterior member and moulded with integral mounting or fixing means for use in securing the cover assembly to a wheel.

2. A wheel cover assembly as claimed in claim 1 and comprising an interior member which comprises an annular flange defining a hollow, right, circular cylinder for reception in the well of a pressed steel wheel.

3. Awheel cover assembly as claimed in claim 1 and comprising an interior member which comprises two or more flanges spaced apart on the circumference of an imaginary, right circular cylinder.

4. A wheel cover assembly as claimed in either of claims 2 and 3wherein the flange(s) originate(s) from a common base element secured to the exterior member.

5. A wheel cover assembly as claimed in any preceding claim wherein the interior and exterior members are secured together by ultrasonic welding.

6. An automobile wheel cover assembly comprising a vacuum-formed fascia member carrying exposed features of visual design on an external surface thereof and an injection moulded mounting member including one or more flanges on the surface of an imaginary, right, circular cylinder, mounting means moulded on the flange(s) for use in securing the assembly in the well of a wheel and a ring integral with the flange(s) and disposed at one axial extremity of the imaginary cylinder, the fascia member and mounting member being secured together by an adhesive or a plurality of ultrasonic spot welds interfacially securing the internal surface of the fascia member to the ring of the mounting member.

7. Awheel cover assembly substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 4 of the accompanying drawings.

8. A method of producing a wheel cover assem buy which method comprises moulding an exterior member for exposure as a fascia, moulding an interior member preferably with integral moulding means for use in securing the cover assembly to a wheel and uniting the interior and exterior members together as an assembly (e.g. by an adhesive or sonic welds) characterized in that the interior member is moulded by injection moulding and the exterior member is made by vacuum forming or another form of pressure moulding.