Steering wheel assembly for a vehicle

A steering wheel assembly includes an armature having a hub, a rim and at least two spokes extending between the hub and the rim, and a damper. The damper connects the at least two spokes and the hub and prevents contact between the spokes and hub. The at least two spokes and hub may include interdigitating projections which the damper prevents from contacting one another. The damper substantially fills a gap between the interdigitating projections and envelops the interdigitating projections. In one embodiment, the damper is annular and the interdigitating projections extend radially and include a base and a distal end having a length greater than a length of the base.

TECHNICAL FIELD

This document relates generally to steering wheel assemblies used in vehicles, and more specifically to a steering wheel assembly having damping capabilities.

BACKGROUND

Steering wheel assemblies are a common component of vehicles and typically include a metal armature, or core, covered by a resin and an outer covering. The armature itself includes a central hub, an outer rim and a number of spokes connecting the rim to the hub in a continuous fashion. Within the vehicle, the steering wheel armature is connected to a steering column or shaft, which is connected through track rods and steering arms of the steering system, or through other known arrangements, to the wheels of the vehicle. When unwanted attributes (e.g., vibrations, nibble, and resonance) are generated during driving, these attributes are transmitted back through the connected sub-components of the steering system and ultimately through the hub, spokes and rim to the hands of the operator of the vehicle.

Prior attempts to reduce or eliminate such unwanted attributes typically involved adding or subtracting mass from the steering wheel assembly in an effort to dampen the attributes. Others included adding individual dampers between the hub and the spokes of the armature. U.S. Pat. No. 2,128,069 to Ashby U.S. Pat. No. 1,056,813 describes a four spoke steering wheel wherein the spokes are steel wires which extend into rubber bushing inserts positioned within a hub of the steering wheel. The four bushings described are locked into position within the hub by a clamping ring secured over the bushings and bolted to the hub. Similarly, U.S. Pat. No. 2,623,405 to Sampson describes a steering wheel assembly with three spokes which extend into rubber bushing inserts positioned with a hub of the steering wheel. The bushings are force fitted into sleeves connected to the hub to provide individual damping of each spoke. While these attempts are capable of reducing unwanted attributes, each involves the addition of several parts to the steering wheel assembly which increases manufacturing times and costs in both labor and parts.

Accordingly, a need exists for a steering wheel assembly capable of reducing or eliminating such unwanted attributes without increasing manufacturing times and costs. Such a steering wheel assembly would necessarily isolate the hub and the spoke from contact. Isolation would preferably be accomplished with a minimum of additional parts and effect on the manufacturing process and the need for additional service.

SUMMARY OF THE INVENTION

In accordance with the purposes and benefits described herein, a steering wheel assembly is provided. The steering wheel assembly may be broadly described as comprising an armature having a hub, a rim and at least two spokes extending between the hub and the rim, and a damper connecting the at least two spokes and the hub. In one possible embodiment, the at least two spokes and the hub include interdigitating projections and the damper prevents contact between the interdigitating projections.

In one other possible embodiment, a first portion of the interdigitating projections extend radially from the hub toward the at least two spokes, and a second portion of the interdigitating projections extend radially from the at least two spokes toward the hub.

In another possible embodiment, the damper is annular. In another, the interdigitating projections include a base and a distal end having a length greater than a length of the base.

In still another possible embodiment, a first portion of the interdigitating projections extend linearly from the hub, and a second portion of the interdigitating projections extend linearly from the at least two spokes.

In yet another possible embodiment, the damper substantially fills a gap between the interdigitating projections. In still another, the damper envelops the interdigitating projections.

In accordance with another aspect of the invention, a steering wheel assembly includes an armature having a hub, and a rim connected to first and second spokes extending toward the hub, and a damper supported by the hub and spanning a gap between the first and second spokes and the hub, wherein the first and second spokes and the hub include interdigitating projections and the damper prevents contact between the interdigitating projections.

In one possible embodiment, the damper is annular. In another, the interdigitating projections extend radially from a side of the hub. In still another, the interdigitating projections include a base and a distal end having a length greater than a length of the base.

In another possible embodiment, the hub includes upper and lower surfaces and the damper extends above the upper surface and below the lower surface.

In still another possible embodiment, the interdigitating projections extend linearly from a side of the hub. In another, the damper is a parallelogram. In still another, the damper substantially fills the gap between the interdigitating projections. In another, the at least two spokes include upper and lower arms.

In one other possible embodiment, the hub includes upper and lower surfaces and the damper extends above the upper surface and below the lower surface.

In accordance with another possible embodiment, a steering wheel assembly includes a hub having a plurality of projections, an outer rim, at least two spokes connected to the rim and extending toward the hub, each of the at least two spokes having a plurality of projections extending toward the hub and interlocking with the plurality of projections of the hub, and a damper supported by the hub for securing at least a portion of the interlocking projections without contact between the plurality of projections of the hub and the projections of each the at least two spokes.

In the following description, there are shown and described several preferred embodiments of the steering wheel assembly. As it should be realized, the assemblies are capable of other, different embodiments and their several details are capable of modification in various, obvious aspects all without departing from the assemblies as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.

Reference will now be made in detail to the present preferred embodiments of the steering wheel assemblies, examples of which are illustrated in the accompanying drawing figures, wherein like numerals are used to represent like elements.

DETAILED DESCRIPTION

Reference is now made toFIG. 1which illustrates a typical steering wheel armature10connected at a central hub12to a partially shown steering column assembly14. As shown, the armature10includes the central hub12, an outer rim16, and two spokes18extending between the hub and the rim. A third, partial spoke20is shown adjacent a lower portion of the outer rim16. The central hub12, outer rim16, and spokes18form a continuous structure, or steering wheel armature10, which is rigidly attached to the steering column assembly14by a bolt22. In this arrangement, any unwanted vibrations, nibble or modal alignment is input into the central hub12and transmitted through the spokes18to the outer rim16and the driver's hands.

In order to eliminate or reduce the transmission of such unwanted attributes to the driver, a steering wheel assembly24includes an additional interface joint. The interface joint is positioned between a pair of spokes26extending from an outer ring28, and a central hub30. As shown inFIG. 2, a damper32covers the interface joint in the described embodiment. The damper30may be a solid or laminated rubber and is annular such that the interface joint between each of the spokes26and the central hub30is covered by the damper30. In the described embodiment, the damper30is doughnut shaped. Other embodiments may include additional spokes extending between the outer ring28and the central hub30with each such additional spoke being isolated from the central hub and covered by the damper32. In addition, the density of the rubber material used in the damper30may be adjusted to balance manufacturing costs and the limitation and/or removal of the unwanted attributes.

As shown inFIG. 3, the interface joint34, which is essentially an air gap, is formed between interdigitating projections which prevents contact between the spokes26and the hub30. Specifically, a first portion of the interdigitating projections36extend radially from either side of the hub30generally toward the spokes26. More specifically, the projections36extend radially from an outer surface or side38of the hub30. A second portion of the interdigitating projections40extend radially from each of the spokes26toward the hub30. Again, the projections40extend radially from an outer surface or side42of the spokes26. The damper32(shown in dashed lines) essentially fills the interface joint34preventing contact between the projections36and40and limiting the transmission of the unwanted attributes from the hub30to the spokes26.

As shown inFIG. 4, the hub32includes an upper surface31and a lower surface33and damper32extends above the upper surface and below the lower surface. As shown inFIGS. 3 and 4, the damper32envelops the interdigitating projections36and40. In other words, the damper32substantially fills the air gap between the interdigitating projections and covers the top and bottom surfaces of the interdigitating projections.

As shown inFIG. 5, the projections36and40include a base44and a distal end46having a length LEgreater than a length of the base LB. The length of the base44and distal end46may vary between hub projections36and spoke projections40depending on design choice or may all be the same within a steering wheel assembly. The differing lengths, however, allow the hub projections36and spoke projections40to form a formidable bond when the damper32fills the gaps formed there between.

Of course, the hub projections and spoke projections could take any number of shapes including, for example, a linear shape as shown inFIG. 6. In this embodiment, an interface joint48, which is again an air gap, is formed between interdigitating projections which prevents contact between spokes50and a hub52. Specifically, a first portion of the interdigitating projections54extend linearly from either side of the hub52generally toward the spokes50. More specifically, the projections54extend linearly from an outer surface or side56of the hub52. A second portion of the interdigitating projections58extend linearly from each of the spokes50toward the hub52. Again, the projections58extend linearly from an outer surface or side60of the spokes50.

A damper62(shown in dashed lines) covers and essentially fills the interface joint48in the described alternate embodiment preventing contact between the projections54and58, and limiting the transmission of the unwanted attributes from the hub52to the spokes50. In other words, the damper62substantially fills the air gap between the interdigitating projections54and58and envelops them and covers a top surface64and a bottom surface66of the hub52. The damper62may be a solid or laminated rubber and is generally rectangular such that the interface joint48between each of the spokes50and the central hub52is covered by the damper.

In an alternate embodiment shown inFIG. 8, the spokes include an upper arm68and a lower arm70. Specifically, a first portion of interdigitating projections36extend radially from either side of the hub30generally toward the upper and lower arms68,70. More specifically, the projections36extend radially from an outer surface or side38of the hub30. A second portion of interdigitating projections40extend radially from each of the upper and lower arms68,70toward the hub30. Again, the projections40extend radially from an outer surface or side42of the upper and lower arms68,70. A damper72(shown in dashed lines) essentially fills the interface joint preventing contact between the projections36and40of the upper and lower arms68,70and limits the transmission of the unwanted attributes from the hub30to the upper and lower arms68,70.

In an alternate embodiment shown inFIG. 9, the spokes include an upper arm74and a lower arm76. Specifically, a first portion of interdigitating projections54extend linearly from either side of the hub52generally toward the upper and lower arms74,76. More specifically, the projections54extend linearly from an outer surface or side56of the hub52. A second portion of interdigitating projections58extend linearly from each of the upper and lower arms74,76toward the hub52. Again, the projections58extend linearly from an outer surface or side60of the upper and lower arms74,76. A damper78(shown in dashed lines) essentially fills the interface joint preventing contact between the projections54and58of the upper and lower arms74,76and limits the transmission of the unwanted attributes from the hub52to the upper and lower arms74,76.

In summary, numerous benefits result from a steering wheel assembly as illustrated in this document. The steering wheel assembly is capable of reducing or eliminating unwanted attributes without increasing manufacturing times and costs. Such a steering wheel assembly would necessarily isolate the hub and the spoke from contact. Isolation would preferably be accomplished with a minimum of additional parts and effect on the manufacturing process and the need for additional service.