Full off-set two-piece fiber reinforced composite wheel using spoke or web area box sections

The present invention relates generally to automobile wheels, and more particularly to injection molded plastic composite automobile wheels.

The automotive industry has increasingly been motivated to provide automobiles with decreased mass. A general trend toward more fuel efficient vehicles has influenced automobile manufacturers to develop more economical, light weight vehicle components. In order to produce vehicles which are lighter and less expensive there has been a strong movement in the automotive industry to develop vehicle body components which have been molded from plastic.

The present invention recognizes that the cost of an automobile can be reduced by minimizing the weight of its wheels. The cost of a lightweight automobile is relatively low because, among other things, a lightweight automobile can be propelled by a relatively small fuel-efficient power plant. Additionally, certain lightweight materials happen to be inexpensive, and easy to manufacture.

Furthermore, the present invention recognizes that still further weight and cost savings would accrue from using plastic composite as the material for the wheels. More particularly, the reduced weight of plastic wheels may make it possible to incorporate a comparatively simplified, cost effective, lighter weight suspension system because of the less unsprung wheel mass.

Although plastic compostite wheels represent substantial benefits, they also present a common drawback of having decreased structural strength. More specifically the compression strength generally is reduced from conventional steel or alloy wheel rims. In order to overcome this problem, it is necessary to provide a reinforced plastic wheel capable of increased structural strength.

It is an object of the present invention to provide a two piece structural fiber reinforced composite wheel.

It is yet another object of the present invention to provide a lightweight automobile wheel that has radial spoke sections that have substantially box shaped cross sections.

A further object of the present invention is to provide a lightweight automobile wheel that meets wheel durability and serviceability requirements under heavy structural loading.

Still another object of the present invention is to provide a lightweight automobile wheel which is simple in structure, inexpensive to manufacture and refined in appearance.

These and other objects of the present invention are obtained by providing a lightweight automobile wheel which includes an outboard unitary composite wheel rim which defines an inboard oriented engagement surface. Additionally, the wheel includes an inboard unitary composite wheel rim that defines an outboard oriented engagement surface which is formed for mating with the inboard oriented engagement surface.

In the preferred embodiment, a plurality of fasteners are engaged with the rims within the spoke sections for holding the rims together. The rims are also held together by an adhesive. The inboard composite wheel rim and the outboard composite wheel rim engage such that the adhesive provides an air tight seal between the two rims making it suitable to accept a tire. The spoke sections join at a central disc-shaped portion having apertures suitably incorporated to engage a wheel hub member. Reinforcing wall portions are incorporated in the spoke sections for structural support.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of the outboard surface of the outboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.

FIG. 2 is a perspective view of the inboard surface of the outboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.

FIG. 3 is a perspective view of the outboard surface of the inboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.

FIG. 4 is a perspective view of the inboard surface of the inboard unitary composite wheel rim constructed in accordance with the teachings of the preferred embodiment of the present invention.

FIG. 5 is a perspective view of the inboard and outboard rim sections aligned prior to engagement.

FIG. 6 is a perspective view of the inboard and outboard rims operatively engaged.

FIG. 7 is a perspective view of a spoke section with a cutaway of the outboard unitary composite wheel rim for purposes of illustrating the interior spoke fastening members.

FIG. 8 is a cross sectional view of a spoke section taken along line 8 — 8 of FIG. 7 to illustrate a fastener interface in a spoke section.

FIG. 9 is a cross sectional view of a lug nut area taken along line 9 — 9 of FIG. 6 shown to illustrate wheel stud, rim, lugnut interface.

The present invention provides a two piece composite wheel. With reference to the drawings, the two piece composite wheel constructed in accordance to the teachings of the present invention is illustrated and identified with reference numeral 10 . More specifically, the two piece composite wheel 10 includes an outboard composite rim 20 and an inboard composite rim 50 , as shown in FIG. 5 . The outboard composite rim 20 and inboard composite rim 50 are both molded of fiber reinforced plastic. One process for creating the fiber reinforced plastic includes injection molding or compression molding around a structural fiber material residing in the mold. The structural fiber material is preformed to encourage repeatable results and may include carbon, fiberglass, KEVLAR, nylon, mesh polymer or the like. The structural fiber material can also comprise a screen-like, woven material or a loose fiber configuration.

Referring now to FIGS. 1 and 2, a perspective view of the outboard face 25 of the outboard composite rim 20 is shown. The outboard composite rim 20 includes a plurality of radial outer spoke sections 27 . The outer spoke sections 27 connect to an outer hub portion 28 in the center of the outboard composite rim 20 . An indented reinforcement section 31 is integrated in the outer portion of the outer spoke sections 27 for structural enhancement. The inboard side of outer spoke sections 27 include outer wall extensions 29 located on each side of the outer spoke sections 27 , best shown in FIG. 2 . The outer hub portion 28 includes an aperture 33 defining the centerpoint of the outboard composite rim 20 . The outer hub portion 28 also includes a plurality of inset portions 32 with disk shaped end portions 34 defining an aperture 35 to receive a wheel stud (not shown). The disk shaped end portions 34 act as the mating surface for lug nuts (not shown). The outer spoke sections 27 extend radially outwardly from the outer hub portion 28 to circumferential wall portion 44 . Intermediate to the outer spoke sections 27 , flange sections 37 protrude inboard from the circumferential wall portion 44 .

FIG. 2 shows the inboard face 40 of the outboard composite rim 20 . The flange sections 37 include a plurality of support fins 42 offsetting the flange sections 37 at an inward angle of the circumferential wall portion 44 . The outer spoke sections 27 include inner wall sections 46 lying substantially perpendicular to the inboard face 40 of the outboard composite rim 20 . The inner surface of the outer spoke sections 27 include boss sections 39 adapted to receive fasteners 70 as shown and described herein with reference to FIG. 8 . The boss sections 39 are connected by inner wall sections 46 providing structural support. Ridge portions 48 extend between the outer wall extensions 29 of the outer spoke sections 27 .

FIG. 3 shows the outboard face 55 of the inboard composite rim 50 . The inboard composite rim 50 includes a plurality of radial inner spoke sections 57 . The inner spoke sections 57 are radially connected to an inner hub portion 58 in the center of the inboard composite rim 50 by an inwardly ramped section 59 . The inner hub portion 58 includes a plurality of outset portions 90 with disk shaped end portions 92 defining an aperture 94 to receive a wheel stud (not shown). The inner hub portion 58 includes an aperture 53 defining the centerpoint of the inboard composite rim 50 .

The inner spoke sections 57 are outwardly offset by wall extension portions 60 connecting the inner spoke sections 57 to a radial step portion 61 of the circumferential wall portion 62 . The wall extension portions 60 of the inner spoke sections 57 include a ramped step portion 65 . The face 67 of the ramped step portion 65 seats to the inboard face 40 of the circumferential wall portion 44 of the outboard composite rim 20 when the inboard composite rim 50 is mated with the outboard composite rim 20 .

The inner spoke sections 57 of the inboard composite rim 50 further include wall sections 72 that seat between the outer wall extensions 29 of the outer spoke sections 27 of the outboard composite rim 20 when the inboard composite rim 50 is mated with the outboard composite rim 20 . The inner spoke sections 57 further include reception portions 74 which receive the boss sections 39 of the outboard composite rim 20 and together accept a fastener 70 as shown in FIG. 8 for securing the outboard composite rim 20 to the inboard composite rim 50 . A wall portion 75 extends from the inboardmost reception portion 74 between the wall sections 72 . An outer flange 81 projects outward from the outer portion of the inner spoke sections 57 . Tab supports 82 extend in an outward direction from the wall extension portions 60 .

The mating surface is defined by and an adhesive is applied to the outside of wall sections 72 , up and around the wall portion 75 and around the inwardly ramped section 59 . The adhesive is further applied to the tab supports 82 , the reception portions 74 and the face 67 of the ramped step portion 65 . Bead extrusions 73 line the mating surface of the outboard face 55 of the inboard composite rim 50 to ensure the adhesive will not overflow as the inboard composite rim 50 and outboard composite rim 20 are mated. It is apparent however, that the bead extrusions 73 may be located along the mating surface of the inboard face 40 of the outboard composite rim 20 .

When the outboard composite rim 20 mates with the inboard composite rim 50 , the face 67 of the ramped step portion 65 of the inboard composite rim 50 mates to the outside of the flange sections 37 of the outboard composite rim 20 . Similarly, the tab supports 82 of the inboard composite rim 50 mate with the inner wall sections 46 of the outboard composite rim 20 . The wall sections 72 , outer flange portions 81 , wall portion 75 and reception portions 74 of the inboard composite rim 50 mate with the outer wall extensions 29 , ridge portions 48 , the inboard face 40 and the boss sections 39 of the outboard composite rim 20 respectively. Accordingly, the inner hub portion 58 of the inboard composite rim 50 mates with the outer hub portion 28 of the outboard composite rim 20 . An air tight fit results around the respective mating portions.

FIG. 4 shows the inboard face 77 of the inboard composite rim 50 . The inner spoke sections 57 of the inboard composite rim 50 include a plurality of inset portions 78 with disk shaped end portions 79 defining an aperture 80 to receive a fastener 70 as shown in FIG. 8 .

FIG. 5 illustrates the alignment of the inboard composite rim 50 and the outboard composite rim 20 prior to engagement. The spoke sections from the respective rims create box sections when joined. Specifically, the outer wall extensions 29 from the outboard composite rim 20 serve as the first parallel walls that lie substantially perpendicular to inner spoke sections 57 of the inboard composite rim 50 and outer spoke sections 27 of the outboard composite rim 20 which serve as the other parallel walls. FIG. 6 illustrates the inboard composite rim 50 engaged to the outboard composite rim 20 . The inner spoke sections 57 of the inboard composite rim 50 align with the outer spoke sections 27 of the outboard composite rim 20 and the outer wall extensions 29 of the outboard composite rim 20 to form substantially box shaped spoke sections.

FIG. 7 and 8 show the interface between inner spoke sections 57 of the inboard composite rim 50 and outer spoke sections 27 of the outboard composite rim 20 . The boss sections 39 of the outer spoke sections 27 of the outboard composite rim 20 are received into the reception portions 74 of the inner spoke sections 57 of the inboard composite rim 50 .

FIG. 9 shows a lug nut 85 engaged with a wheel stud 89 extending through an aperture 69 of the inboard composite rim 50 and an aperture 35 of the outboard composite rim 20 which connects the wheel 10 to a vehicle (not shown).

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.