Two-piece steering wheel back-cover for improved safety performance

A new type of steering wheel cover is designed for use with a steering wheel that has one or more spokes. The cover will include an upper portion and a lower portion. Generally, the lower portion is the region or portion of the steering wheel that is positioned at the junction between the spoke and the steering wheel rim. The upper portion and the lower portion are separated by at least one split line. The split line is designed such that during a crash or accident, the upper portion and the lower portion will collapse into each other and absorb some of the energy of the impact.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to steering wheel covers for automobiles, trucks, and motor vehicles. More specifically, the present invention relates to covers adapted to enclose portions of the steering wheel assembly.

2. Description of Related Art

Steering wheel back covers are commonly used in vehicles to act as an aesthetic and protective cover for the inner workings of the steering wheel and its interface with the steering column. In modern vehicles, steering wheel covers also serve to protect the delicate electronics attached to controls positioned in the steering wheel or placed in control levers extending from the steering column. As a result, steering wheel back covers are generally substantially rigid in structure. Moreover, most steering wheel covers and steering wheel systems are held in their proper position through the use of screws or other fasteners. As a result, the overall steering wheel system (including the steering wheel cover) is often a very stiff, rigid product.

Unfortunately, the rigidity of these steering wheel systems has created some problems and design concerns for vehicle manufacturers. The reason for this is that during a crash or accident, the driver of the vehicle will often impact the steering wheel. Generally, the steering wheel is designed such that the steering wheel will bend or deform during impact in order to dissipate some of the energy of the crash and properly decelerate the vehicle occupant. However, the increased rigidity of the steering wheel covers reduces the ability of the steering wheel system to deform or bend during a crash. As such, these rigid steering wheel covers will significantly reduce the ability of the steering wheel system to dissipate some of the energy of the crash.

As is known in the art, the problems associated with the use of rigid steering wheel systems are exacerbated for smaller, lighter vehicle occupants (such as “petite” female drivers that fall in the 5thpercentile for height and weight). In general, smaller and lighter people tend to position their seats very forward and close to the steering wheel (i.e., so that their feet can reach the pedals). Because these individuals are so close to the steering wheel, these people will generally strike the lower portions of the steering wheel very forcefully and quickly during a crash. (This lower region of the steering wheel that is impacted by smaller, lighter individuals is often referred to as the “6:00 o'clock region” as this region of the circular wheel is proximate to the position of the numeral “6” on the standard circular-shaped clock.)

In order to properly protect these smaller, lighter individuals, it is desirable to have the steering wheel system bend in a controlled fashion to dissipate some of the energy of the impact. Accordingly, vehicle manufacturers have put forth specifications which require steering wheel producers to develop a system that will allow the 6:00 o'clock region of the steering wheel to properly and easily deform/bend during impact. However, to date, an acceptable system that accomplishes this goal has not yet been achieved without compromising the desired stiff cover design geometry.

Accordingly, it would be an advancement in the art to provide an acceptable steering wheel system (including a steering wheel cover) that will properly and adequately deform/bend during impact and will protect the smaller, lighter vehicle driver. Such a system is disclosed herein.

BRIEF SUMMARY OF THE INVENTION

A new type of steering wheel cover for use in a steering wheel system is disclosed herein. The steering wheel cover is designed to be used with a steering wheel that includes one or more spokes that extend from the center of the wheel to the outer rim of the wheel. The steering wheel cover will generally be made of molded plastic materials (such as thermoplastic), although other materials may also be used.

The steering wheel cover includes an upper portion and a lower portion. The lower portion is the portion of the cover that is positioned proximate the spokes whereas the upper portion is the portion proximate the center. The upper and lower portions are separated via a split line. More than one split line may also be used. The split line is a cut, incision or other separation that is placed between the upper and lower portions. Generally, the division of the split line will be relatively small such that the edges of the upper portion and the lower portion will effectively abut each other. In other embodiments, the split line will not be a complete separation between the upper and lower portions; rather, the split line will comprises a series of perforations in the cover that are designed to tear or separate in the event or a crash.

The split line is transverse (i.e., across) the spoke and is positioned at or near the desired bending axis of the cover for energy absorption performance. The bending axis is a theoretical transverse line around which the complete steering wheel system that lacks any sort of split lines (or tear seam, area of reduced thickness, etc.) is desired to bend for ideal energy absorption performance as required by the vehicle crash characteristic. The bending axis is often located along the longitudinal length of the lower spoke and may vary according to each particular steering wheel embodiment.

The use of the split line will provide significant advantages over previously known steering wheel covers and steering wheel systems. Specifically, in the event of an accident or crash, the cover of the present embodiments will stiffen the overall steering wheel system. During an impact or crash, the cover will begin to deform and collapse inwardly as a result of the vehicle occupant being thrust forward into the steering wheel system. As the steering wheel cover begins to deform due to the impact, the split line between the upper and lower portions will cause the portions to collapse into one another. In some embodiments, this occurs by having the upper portion (or a leading edge or region of the upper portion) collapse and/or slide under the lower portion during the impact. Other embodiments are designed such that during impact, the portions will collapse into one another by having the lower portion (or a leading edge or region of the lower portion) slide under the upper portion.

The fact that the upper and lower portions will collapse into each other during an impact provides significant advantages over previously known systems. Specifically, this collapsing of the portions means that the steering wheel system will be less rigid (overall) and more susceptible to desired deformation and bending during a crash. Accordingly, vehicle occupants (including smaller, lighter occupants) that impact the 6:00 o'clock region of the steering wheel will receive greater protection.

DETAILED DESCRIPTION OF THE INVENTION

Referring first toFIG. 1, a steering wheel system10of the present embodiments is illustrated. The system10will include a steering wheel12that may be attached to a steering column16. The steering wheel system10may also include a steering wheel back cover18(or steering wheel cover) that is designed to house all or a portion of the steering wheel12and/or the steering column16. As is known in the art, the steering wheel back cover18may include an orifice22that permits the back cover10to be installed about the steering column16.

Additionally, the steering wheel cover18may include one or more accessory openings26through which an accessory control30positioned near the steering wheel12protrudes for access by a vehicle operator (not shown). Such accessory controls30may include gear shift levers, headlight/turn signal levers, windshield wiper levers, speed controls, radio controls, a message center, or other controls which may be conveniently placed near a steering wheel12for easy access by a vehicle operator.

The back cover18is made of a molded plastic material such as thermoplastic that has been molded into the proper shape/configuration. Testing has shown that these types of plastic materials are well suited for aesthetic and cost effective covering of the steering wheel than other types of materials. However, depending on the specifications and the particular embodiment, different materials may also be used.

The steering wheel12includes one or more spokes (not shown specifically because of being obscured by the back cover18, but generally identified by reference number34. As is known in the art, spokes34are routinely added to steering wheels as a means of connecting the rim38of the steering wheel12to a center portion that may house an airbag (not show) and/or other features including the vehicle's horn, user selection buttons, message screens, “cruise control” or other speed controls, radio controls, etc. The steering wheel12shown inFIG. 1has three spokes34; however other embodiments in which the wheel12has more or less than three spokes34are also possible and known in the art.

In the embodiment shown inFIG. 1, the steering wheel cover18extends along the length of the spokes34until the spokes34intersect with the rim38of the steering wheel12, thereby housing at least a portion of the steering wheel12, namely the spokes34. That portion of the steering wheel12(obscured from view by the back cover18) that is housed within the back cover18is generally designated by reference number35. However, other embodiments may also be constructed in which the cover18ends prior to the junction between the spoke34and the rim38.

InFIG. 1, the back cover18is shown to be substantially rectangular in shape with rounded corners and edges. Those of skill in the art will recognize that these structures may have a wide variety of shapes within the scope of the invention. Specifically, the cover18may be constructed to form a round or ovoid cylindrical structure, or may be more significantly flattened to avoid intrusion of the cover18into the vehicle operator's field of view.

Referring now toFIG. 2, a side view of the system10is illustrated for purposes of illustration and clarity. The steering wheel system10is shown proximate a vehicle occupant84. As can be seen inFIGS. 1 and 2, the cover18includes an upper portion50and a lower portion54. Generally, the lower portion54is the region or portion of the steering wheel12that is positioned at the junction between the spoke34and the steering wheel rim38. The upper portion50is the portion proximate the orifice22and steering column16. It should be noted however that the portions50,54are designated as being “upper” and “lower” in the present exemplary embodiment, one of skill in the art will recognize that the structures of the portions50,54may be adapted to be attached about a steering wheel assembly in a large number of orientations, including the exemplary “upper” and “lower” configuration shown.

The upper and lower portions50,54are separated via a split line60. More than one split line60may also be used. The split line60is a cut, incision, separation, or weakening of the material that is placed between the upper and lower portions50,54. Generally, the split line60will be relatively small such that the edges of the upper portion50and the lower portion54will effectively abut each other. It should also be noted that is some embodiments, the split line60will not be a complete separation between the upper and lower portions50,54. Rather, in some embodiments, the split line comprises a weakening of the material or a series of perforations in the cover18that are designed such that in the event of an impact, the perforations will tear or separate so that the upper and lower portions50,54become distinct elements.

It should also be noted that in the embodiment shown inFIG. 2, the split line60extends along substantially the entire perimeter of the cover18, which in essence, separates the back cover18into two distinct pieces. However, other embodiments may also be constructed in which the split line60does not extend along substantially the entire perimeter of the cover18. Rather, in these embodiments, one or more of the edges64of the split line60will still be joined together.

The split line60is substantially transverse to the spoke34. As used herein, the term “transverse to the spoke” means that the split line60will be perpendicular or substantially perpendicular to the spoke34as it extends outwardly towards the rim38from the center42. In the embodiment shown inFIG. 2, the split line60is exactly perpendicular to the spoke34as it extends outwardly away from the center42.

In many of the presently preferred embodiments, the split line60will also be positioned at or near the bending axis68of the steering wheel cover18. (The bending axis68is shown inFIG. 1). The “bending axis” is a theoretical transverse line around which the complete steering wheel system is desired to bend for ideal energy absorption performance as required by the vehicle crash characteristic. The bending axis will generally be located along the longitudinal length of the spokes34and may vary according to each particular steering wheel embodiment. Factors that will influence and determine the location of the bending axis68include the material used to make the steering wheel and the cover, the size, length and dimensions of the steering wheel system, the rigidity of the steering wheel system, the presence/location of any screws or fasteners that are designed to restrict movement of steering wheel components etc. Other factors influencing the position of the bending axis68includes the point of impact (i.e. 6:00) and the direction of the force impacting the steering wheel. Those of skill in the art will know and understand how the location of the bending axis68may be determined. In many of the present embodiments, the position of the bending axis68is selected such that the point of impact will be at or near the 6:00 position and will be generally perpendicular to the steering wheel. In many embodiments, the bending axis68will be perpendicular or substantially perpendicular to the spoke34.

Such positioning of the split line60at or near the bending axis68has significant advantages. Specifically, as is discussed in greater detail herein, the split line60will stiffen the steering wheel system during a crash. Rather, the presence of the split line60allows the steering wheel cover18to collapse and deform during a crash as a means of absorbing some of the energy of the impact.

Referring still toFIG. 2, optional features of the steering wheel system10is illustrated. As is known in the art, one or more screws (or other fasteners) are often used to attach the cover18to the steering wheel12and to lock the components of the steering wheel system10in the proper position. Such screws generally result in increasing the overall rigidity (stiffness) of the steering wheel system10. However, as is shown inFIG. 2, the cover18may be designed such that one or more of these screws are absent (either removed or omitted). Specifically, other embodiments may be constructed in which the “12:00 o'clock” screws72—i.e., the screws that attach the cover18to the center42of the steering wheel18—have been removed. Other embodiments may also be constructed in which other screws that attach/connect the cover18to the steering wheel18have been removed or omitted. Other screws may also be removed or omitted, including screws that fit into a rear portion of the steering wheel center42.

This removal or omission of the screws72(or other screws) may have the effect of decreasing the rigidity of the steering wheel system10and allowing the system10to more easily deform and absorb some of the energy of the crash. It should be noted that, in some embodiments, removal or omission of the screws72(or other screws) may cause additional rattling, buzzing, or squeaking of the steering wheel system10and/or may change the overall visual appearance and “finish” of the steering wheel system10. Accordingly, some vehicle manufactures may choose to include the screws72(or other screws) as part of the steering wheel system10.

Referring now toFIG. 3, the steering wheel cover18of the present embodiments is illustrated after the steering wheel system10has undergone impact with a vehicle occupant84. Unlike many of the previously known steering wheel covers, the cover18acts to facilitate the desired bending of the system. This is because of the presence of the split line60in the cover18acts to reduce the stiffness. Specifically, during an impact or crash, the cover18will begin to deform and collapse inwardly as a result of the vehicle occupant being thrust forward into the steering wheel system10, resulting in a force (as shown by the arrow) being applied to the steering wheel12. As the steering wheel cover18begins to deform due to the impact, the split line60between the upper and lower portions50,54will cause the portions50,54to collapse into one another, as shown by the dashed lines80. In some embodiments, this occurs by having the upper portion50(or a leading edge or region of the upper portion50) collapse and/or slide under the lower portion54during the impact. Other embodiments, such as the one shown inFIG. 3, are designed such that during impact, the portions50,54will collapse into one another by having the lower portion54(or a leading edge or region of the lower portion54) slide under the upper portion50. Yet further embodiments may be made in which the upper and lower portions50,54will slide/collapse into each other in a different manner.

The fact that the upper and lower portions50,54will collapse into each other during an impact provides significant advantages over previously known systems. Specifically, this collapsing of the portions50,54means that the steering wheel system10will be less rigid (overall) and more susceptible to deformation and bending during a crash. Accordingly, vehicle occupants (including smaller, lighter occupants) that impact the 6:00 o'clock region of the steering wheel12will receive greater protection. Moreover, the collapsing of the portions50,54also means that the steering wheel12will deform without the possibility that pieces/debris from the steering wheel12will impact the occupant during a crash.