Abstract:
A steering wheel provided with a remote control switch. The remote control switch includes a user-settable unit and a variable circuit unit for changing a function of the remote control switch according to the configuration of the user-settable unit; for example, the function of the remote control switch may be changed by attaching a removable button with the desired function.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0120022 filed in the Korean Intellectual Property Office on Nov. 30, 2006, the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   (a) Field of the Invention 
   The present invention relates to a steering wheel provided with a remote control. 
   (b) Description of the Related Art 
   Recently, steering wheels have been provided with remote controls. Since the configuration of buttons on such a steering wheel is predetermined by the manufacturer, locations of the buttons may not correspond to a driver&#39;s preference or usage frequency. 
   The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
   SUMMARY OF THE INVENTION 
   The present invention provides a steering wheel having a remote control with a user-settable unit configuration. 
   An exemplary embodiment of the present invention provides a steering wheel of a vehicle that includes at least one remote control switch. The remote control switch includes a user-settable unit and a variable circuit unit for changing a function of the switch according to the configuration of the user-settable unit. 
   The user-settable unit may be inserted into and extracted from one of a plurality of housings disposed at predetermined positions of the steering wheel, and may have a cylindrical or prism shape. The user-settable unit may include: a display portion for displaying a function at the upper surface thereof; a guide protrusion for guiding the insertion/extraction of the user-settable unit into/from a housing at a side surface thereof; and a plurality of contact pins at a bottom surface thereof. The number and configuration of contacts pins varies according to the function of each user-settable unit. 
   Each housing may be provided with a guide groove corresponding to the guide protrusion portion, and the housing may be provided with a printed circuit substrate having a plurality of contact holes on a bottom surface thereof. The contact pins of the user-settable unit are respectively electrically connected to each corresponding contact hole when the user-settable unit is inserted into the housing. 
   One contact pin and one contact hole corresponding to the one contact pin may form one switch, and combinations of other contact pins and other contact holes respectively corresponding to the other contact pins may form a plurality of other switches. The user-settable unit may be cylindrical, and each housing may have a cylindrical cavity portion for accommodating the cylindrical user-settable unit. Each housing may be provided with a cover plate having an opening portion corresponding to the cavity portion. The user-settable unit may have sufficient thickness to be easily inserted to and extracted from the cavity portion. 
   When the knob is pressed and a corresponding switch is closed, one signal may be input through the switch and transmitted to the other switches electrically connected thereto such that a function of the switch is performed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of a steering wheel according to an exemplary embodiment of the present invention. 
       FIG. 2  is a schematic diagram of a remote control switch of a steering wheel capable of changing a switch button arrangement according to an exemplary embodiment of the present invention. 
       FIG. 3  is an exploded perspective view of a remote control switch of a steering wheel according to an exemplary embodiment of the present invention. 
       FIG. 4  illustrates a variable circuit unit of a remote control switch of a steering wheel according to an exemplary embodiment of the present invention. 
       FIG. 5  is a schematic diagram showing a relation of a switch function and a contact pin arrangement of a user-settable unit of a remote control switch of a steering wheel according to an exemplary embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A steering wheel according to an exemplary embodiment of the present invention is described in detail with reference to the figures. 
   A steering wheel  10  is provided with a remote control switch  20  having a plurality of user-settable units  21 , preferably at a position where a driver&#39;s hands come directly in contact therewith. The user-settable units  21  may be covered with a cover, which may be made of a stretchable material for user comfort. The user-settable units  21  may indicate various control instructions, such as audio on/off or air conditioner on/off. In order to indicate the control instructions, the user-settable units  21  may be provided with a control instruction-printed display portion thereon. 
   For example, as shown in  FIG. 1  and  FIG. 2 , a the user-settable units  21  may include a display portion RES for indicating shut down/circulation of outdoor air, a display portion CANCEL for indicating on/off of TV, radio, or lighting, and a display portion SET for indicating on/off of a rear-monitoring camera. The user-settable units  21  may be replaced with different user-settable units. These user-settable units  21  are provided with a control instruction-printed display portion for indicating each control instruction. 
   As shown in  FIG. 3 , the user-settable units  21  may be cylindrical, and may be respectively accommodated into housings  23 , each provided at a fixed position on the steering wheel  10 . While three housings  23  are illustrated for simplicity, the present invention is not limited to any number of housings  23 . Each housing  23  may have a cavity portion  24  corresponding to the shape of the user-settable unit  21  such that it may accommodate the user-settable unit  21 . For example, setting unit  21  and cavity portion  24  may both be cylindrical. The housing  23  may further be provided with a removable cover plate  22  whose shape corresponds to the cavity portion  24 . The housing  23  may further be provided with a printed circuit substrate  25  at the bottom portion thereof. 
   The user-settable unit  21  may be provided with a knob thereon having a height above cavity portion  24  for easily grasping to insert and extract the user-settable unit  21 . The knob may include a spring, disposed in the user-settable unit  21 , for biasing the knob outward. 
   The user-settable unit  21  may be provided with a guide protrusion portion  21 a at a side surface thereof such that it is connected with a guide groove  24   a  formed at a side surface of the cavity portion  24 , and accordingly, the user-settable unit  21  is easily accommodated into the cavity portion  24  of the housing  23 . 
   How to change a function of the remote control switch  20  will now be described in detail with reference to  FIG. 4  and  FIG. 5 . 
   As shown in  FIG. 4 , in an exemplary embodiment, the printed circuit substrate  25  has four contact holes  1 ,  2 ,  3 , and  4  arranged thereon; however, the present invention is not limited to any particular number of contact holes. These contact holes  1 ,  2 ,  3 , and  4  are all electrically connected, and the first contact hole  1  is connected to a main switch  26 . The second to fourth conductive contact holes  2 ,  3 , and  4  are connected to a decoder  27  and a switch operation circuit  29 . 
   Referring to  FIG. 5 , the user-settable unit  21  is provided with a plurality of contact pins  1   a ,  2   a ,  3   a , and  4   a  electrically connected at the lower surface thereof such that they may set each function as a switch. The contact pins  1   a ,  2   a ,  3   a , and  4   a  are disposed in correspondence with the positions of the contact holes  1 ,  2 ,  3 , and  4 . When the user-settable unit  21  is accommodated into the cavity portion  24  of the housing  23 , the contact pins  1   a ,  2   a ,  3   a , and  4   a  are respectively inserted into the contact holes  1 ,  2 ,  3 , and  4 , and accordingly, they are electrically connected to the contact holes  1 ,  2 ,  3 , and  4 . The variable electrical connections formed by the pins  1   a - 4   a  and respective ones of the holes  1 - 4  define a variable circuit unit  20 . 
   Accordingly, when the main switch  26  is closed, an electrical signal is input through the first contact hole  1 , and passes through the contact pin  1   a  of the user-settable unit  21 , via at least one contact pin  2   a ,  3   a , and  4   a  selectively formed on the user-settable unit  21  and the corresponding second, third, and/or fourth contact hole  2 ,  3 , and  4  to the decoder  27 . The decoder  27  decodes a switch function indicated by the electrical signal and transmits the decoded signal to the switch operation circuit  29  such that the switch operation circuit  29  performs the corresponding function. 
   That is, as seen in  FIG. 5 , any number of contact pins  1   a ,  2   a ,  3   a , and  4   a , up to the number of contact holes  1 ,  2 ,  3 , and  4 , may be selectively provided according to a function expressed on the display portion of each user-settable unit  21 . 
   According to an exemplary embodiment of the present invention, the remote control switch  20  may output an electrical signal corresponding to the predetermined value through the decoder  27  when the user-settable unit  21  having the combined contact pins is inserted into the desired housing  23  and the main switch  26  is closed. 
   When the main switch  26  is closed, the input signal passes through the decoder  27  according to the arrangement of the contact pins  1   a ,  2   a ,  3   a , and  4   a  of the user-settable unit  21 . Accordingly, the signal input when the knob is pressed may be converted into a signal having eight paths formed by the combination of the second, third, and fourth pins. Accordingly, the switch function may be set according to the presence of each contact pin  1   a ,  2   a ,  3   a , and  4   a  of the user-settable unit  21 . 
   While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.