Abstract:
A plurality of steering wheel sections can be joined to form a steering wheel. A member is partially disposed within a first steering wheel section cavity and partially disposed within a second steering wheel section cavity. A plurality of support arms each have disposed therein a support arm extension. At least one separation mechanism is configured to break a joint between first and second steering wheel sections.

Description:
BACKGROUND 
     Oblique impacts cause particular risks for vehicle occupants. An oblique impact is one in which a vehicle strikes another object at an angle, e.g., at an angle of a longitudinal axis of the vehicle with respect to the object, e.g., the angle being approximately 15 degrees. When an oblique impact occurs at a front of a vehicle, a vehicle occupant may move at an angle with respect to the longitudinal axis of the vehicle. That is, when an oblique impact occurs, the vehicle occupant may be moved in a direction determined by the angle of impact, i.e., the occupant or at least the occupant&#39;s head and/or upper body, may be moved in a direction at the angle to the longitudinal axis of the vehicle of the oblique impact. Accordingly, vehicle safety mechanisms (e.g., a restraint system) that protect an occupant in the case of a head-on collision may provide less or inadequate protection in the case of an oblique impact. 
     For example, a driver airbag (DAB), e.g., deployed from a vehicle steering wheel, may provide inadequate protection for the driver upon an oblique impact. In a non-oblique impact, e.g., a head-on collision, a DAB, upon being deployed, may be impacted by the driver&#39;s head in or near a center of the airbag, whereby the airbag will generally be supported by the vehicle steering wheel directly. However, in the case of an oblique impact, the driver&#39;s head may strike the airbag (e.g., the DAB) at a less than 90 degree angle causing the head to rotate outward and slip off the airbag completely. In this case, the steering wheel will provide inadequate support for the airbag, and the driver is more likely to suffer a head injury and/or a suffered head injury may be more severe. 
    
    
     
       DRAWINGS 
         FIG. 1  is a perspective view of an example of a steering wheel system including an extensible steering wheel in a non-extended state. 
         FIG. 2 . is a perspective view of the steering wheel system of  FIG. 1  illustrating the extensible steering wheel in an extended state. 
         FIG. 3  is a cross-sectional view of a portion of a steering wheel of the system of  FIG. 1  in a non-extended state. 
         FIG. 4  is a cross-sectional view of a portion of a steering wheel of the system of  FIG. 1  in an extended state. 
         FIG. 5  illustrates a perspective view including further example elements of the system of  FIG. 1 , with the steering wheel in a non-extended state. 
         FIG. 6  illustrates a perspective view including further example elements of the system of  FIG. 1 , with the steering wheel in an extended state. 
         FIG. 7  provides a perspective view of the steering wheel system of  FIG. 1  where the steering wheel is in an extended state and a passive restraint has been deployed. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein and illustrated in the various figures is an extensible steering wheel system  10 . An extensible steering wheel  12  includes extensible support arms  22  and extension members  34 , whereby the steering wheel  12  may be extended to provide a greater reaction surface for a passive restraint, e.g., airbag,  36 , then would be provided by an extended steering wheel  12 . 
       FIG. 1  is a perspective view of an example of a steering wheel system  10 , including an extensible steering wheel  12  in a non-extended state, while  FIG. 2  is a perspective view of the extensible steering wheel system  10  of  FIG. 1  illustrating the extensible steering wheel  12  in an extended state. As illustrated in  FIG. 1 , in a non-extended state the steering wheel  12  includes two steering wheel sections  14  connected or joined at a joint  24 . Extensible support arms  22  mount the steering wheel  12  on a steering column assembly  32 , which includes a steering column  16  and a steering wheel cover support  26 . Although two support arms  22  are shown in the present illustrations, additional support arms  22  are possible. Further, steering wheel sections  14  are shown as two half-pieces of the steering wheel  12 , but could include more than two sections  14 . In general, each steering wheel section  14  requires at least one support arm  22 , but could be supported by more than one support arm  22 . A support arm  22  may be attached to a steering wheel section  14  using one or more of a variety of known mechanisms, e.g., glue, bolts, welds, etc. 
     The arms  22  may be mounted on the assembly  32  in a conventional manner, e.g., using bolts, welds, or the like. However, as seen in  FIG. 2 , the support arms  22  may include respective support arm extensions  30 . Likewise, the steering wheel  12  may include two or more extension members  34 . In general, an extension member  34  is provided for each joint  24  between steering wheel sections  14 . The arm extensions  30  and extension members  34  are generally tubular to match a shape of the steering wheel sections  14  and support arms  22 . Further, arm extensions  30  and extension members  34  may be formed of any resilient, flexible, material providing sufficient strength and flexibility for the steering wheel system  10  to perform as disclosed herein. For example, extensions  30  and/or extension members  34  could be formed of rubber, plastic, etc. 
     Various mechanisms may be used to trigger a transition of the steering wheel  12  from a non-extended state, such as is shown in  FIG. 1 , to an extended state, such as is shown in  FIG. 2 . Further,  FIGS. 3 and 4  provide cross-sectional views of a portion of the steering wheel  12  in a non-extended state, and an extended state, respectively. As seen in  FIGS. 3 and 4 , a wall of each steering wheel section  14  may define a generally tubular interior cavity  15 , each cavity  15  accommodating at least a portion of a member  34 . Further, the members  34  are generally formed to be accommodated within a cavity  15 , i.e., a diameter of a tubular member  34  is generally close, e.g., within a millimeter or less, to a diameter of a tubular cavity  15 . 
     Moreover, the members  34  may include flanged ends  38 . A first flanged end  38  of a member  34  may be affixed to an end of a first steering wheel section  14 , e.g., using glue or other bonding, such that the flanged and  38 , and hence the member  34 , remains securely affixed to the section  14  when the steering wheel  12  transitions from a non-extended to an extended state. A second flanged end  38  of the number  34  may be retained in a second section  14  of the steering wheel  12  by a circumferential lip  40  when the steering wheel  12  transitions from a non-extended to an extended state. Accordingly, the lip  40  may limit an extension of the steering wheel  12 , thus providing a shape of the extended steering wheel  12  to support a passive restraint  36  (see  FIG. 7 ), e.g., an airbag. 
     Although not illustrated in separate drawings to avoid duplication, the support arms  22  may include structures similar to the lip  40  for retaining a flange or the like of a support arm extension  30  when the steering wheel  12  transitions from a non-extended to an extended state. Alternatively or additionally, an end of a support arm extension  30  may be securely affixed to a steering wheel section  14  or the steering column assembly  32  such that a bond affixing the extension  30  is not broken when the steering wheel  12  transitions from a non-extended to an extended state. 
     In addition to accommodating at least a portion of a member  34 , a cavity  15  may also accommodate a triggering mechanism  42 . For example, a triggering mechanism  42  may include a gyro device such as is known, a loaded spring, or some other mechanical device biased against an end of the member  34 . A controller or the like in a vehicle, e.g., an airbag controller, etc., may be used to actuate the triggering mechanism  42 , thereby causing the sections  14  to separate at the joint  24 . For example, a controller could generate a signal for the triggering mechanism  42  using a crash detection algorithm utilizing crash data measured from a vehicle based sensor, such as is known. Such controllers are generally known as including a processor and a memory, the memory storing program instructions executable by the processor, e.g., here a controller could include programming for determining when to provide instructions to trigger a mechanism  42  and/or other separation mechanism. Instructions such as a signal to actuate the triggering mechanism  42  could be communicated via a Controller Area Network (CAN) bus or similar communications mechanism in a vehicle. 
     As an alternative, or in addition, to the triggering mechanism  42 , other separation mechanisms could be used to cause breakage of the joint  24  and extension of the steering wheel  12 . For example, a portion of gas used by the inflator system of a steering wheel airbag could be directed into a cavity  15 , and used to push a member  34 , thereby breaking the joint  24 . Yet further, the joint  24  could include an adhesive, glue, or other bond that dissolved or lost adhesive force upon application of high heat. In this example, a member  34  could be pretensioned with a loaded spring or the like, and the triggering mechanism could ignite a burning to break the joint  24 , whereupon the pretensioning mechanism, e.g., the loaded spring, could force the members  34  to deploy and the steering wheel  12  to thereby extend. 
     In general, the controller is configured to trigger extension of the steering wheel  12  prior to deployment of an airbag  36  (see  FIG. 7 ) or the like. For example, a steering wheel  12  may be extended within substantially the first 20 milliseconds that an oblique impact is detected, whereupon an airbag  36  could then be deployed. 
     In any case, the joint  24  is generally configured to be broken by a predetermined pressure, e.g., a pressure resulting from actuation of the triggering mechanism  42 . For example, sections  14  may be glued or otherwise bonded to one another at a joint  24 . A strength of the glue or other bond may be calibrated to retain the steering wheel  12  in a non-extended state absent a force exerted by actuation of the triggering mechanism  42 . The triggering mechanism  42 , in turn, may be configured to cause a force greater than the bonding force at the joint  24  when the triggering mechanism  42  is actuated, thereby breaking the joint  24  and transitioning the steering wheel  12  from a non-extended state to an extended state. 
       FIG. 5  is a perspective view of an example of the steering wheel system  10  of  FIG. 1  including an extensible steering wheel  12  in a non-extended state.  FIG. 5  illustrates a perspective view including further example elements of the system  10 , including a steering wheel hub cover  18  that may be fitted over the steering wheel cover support  26  (not visible in  FIG. 5 ). As is known, a compartment formed by the wheel hub cover  18  and steering wheel cover support  26  may include various components, including a passive restraint such as an airbag, e.g., a (DAB). Alternatively or additionally, an airbag may be deployed from a steering column  16 . Other components may be housed in a compartment formed by the cover  18  and cover support  26 , such as a vehicle electronics or the like. 
     In any event, the cover support  26  may include tear grips  20 , e.g., molded plastic or the like fitted around the steering wheel  12 . As illustrated in  FIG. 6 , the tear grips  20  are generally configured to break when the triggering mechanism  42  causes the steering wheel sections  14  to be pushed apart, and the member  34  as well as the support arm extensions  30 , to be deployed. Alternatively or additionally, some other portion of the wheel hub cover  18  and/or the cover support  26  may be configured to break when the steering wheel  12  transitions from a non-extended state to an extended state. 
       FIG. 7  provides a perspective view of the steering wheel system  10  of  FIG. 1  where the steering wheel  12  is in an extended state and a passive restraint, in this case, an airbag, e.g., a DAB,  36  has been deployed. This can be seen, the extended steering wheel  12  provides support for the airbag  36  even at edges thereof. Accordingly, a driver head and/or other body part striking the airbag  36  will be better protected in an oblique impact, because the airbag  36  will be supported at edges thereof. Thus, the presently disclosed system  10  provides the advantage of enhancing driver safety in an oblique impact situation. A further advantage is that parameters for installing and deploying a passive restraint such as a driver-side airbag need not be changed to use the system  10  and achieve enhanced driver safety. 
     In addition to the steering wheel system  10  disclosed herein, it should be understood that a process for extending the steering wheel  12  and/or deploying a passive restraint  36  is also disclosed herein. For example, upon detection of an oblique impact by a controller of a vehicle, e.g., as discussed above, the triggering mechanism  42  may actuate, whereby a pressure or force may be exerted on a member  34  within a steering wheel section  14  cavity  15 . Moreover, as discussed above, a joint  26  between steering wheel sections  14  will be broken upon application of an appropriate force, resulting in deployment of a member  34  stored in one or more section  14  cavities  15 , as well as deployment of a support arm extension  30  stored in a support arm  22 . Once the member  34  and support arm extension  30  are deployed, the steering wheel  12  has transitioned from a non-extended state to an extended state. 
     As used herein, the adverb “substantially” modifying an adjective means that a shape, structure, measurement, etc. may deviate from an exact described geometry, distance, measurement, etc., because of imperfections in materials, machining, manufacturing, etc. 
     In the drawings, the same reference numbers indicate the same elements. Further, some or all of these elements could be changed. Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims. 
     All terms used in the claims are intended to be given their ordinary meaning as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.