Abstract:
A gauge assembly is disclosed and includes a gauge surface including graphics representing a vehicle operating parameter and a pointer supported for movement about an axis to indicate a current condition of the vehicle operating parameter by pointing to a specific location on the gauge surface. A cap mounted to the pointer along the axis is formed from a plastic film material different than the material forming the pointer.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/738,427 filed on Dec. 18, 2012. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to vehicle instrument panels and clusters, and more specifically to a pointer for a gauge that includes an improved pointer cap and method of mounting the pointer cap to a pointer. 
       BACKGROUND 
       [0003]    Vehicles include instrument panels to communicate information indicative of operation to an operator. Motor vehicles include instrument panels with several gauges and dials that communicate vehicle conditions such as speed, engine rpm, temperature, oil pressure along with many other operational parameters. A pointer is typically provided that rotates about a fixed axis to communicate current values of an operational parameter. Pointers are often illuminated to further enhance visibility. Light sources that direct light along the axis or rotation can cause a bright spot at the axis on the pointer. The bright spot is shielded by a pointer cap. The pointer cap typically includes press fit pins that are received within the corresponding parts of the pointer. The fit between the pointer and the pins of the cap must be maintained within predefined tolerances to assure a proper desired fit. The pointer and cap are typically molded parts, and the additional features can complicate molding operations and design. 
         [0004]    Accordingly, it is desirable to design and develop a pointer and cap that reduce cost while maintaining the desired appearance and function. 
       SUMMARY 
       [0005]    A gauge assembly according to an exemplary embodiment of this disclosure, among other possible things includes a pointer assembly that rotates about an axis A. The pointer assembly includes a pointer, a pointer cap and a pointer shroud. 
         [0006]    Light is communicated to a reflective surface of the pointer and directed into a pointer needle. Some of the light is reflected through the first reflecting surface and may create a bright spot that is not desirable and, therefore, the pointer cap is provided and attached to the pointer. The cap blocks light to prevent bright spots from being visible to an operator. A shroud is assembled to a bottom portion of the pointer to further block and shield light that may be emitted in a direction that is not desirable. The example pointer cap and the pointer shroud are fabricated from a thin film material or applique to provide a substantially thin and lightweight structure. 
         [0007]    The thin film material simplifies assembly and provides for the use of adhesive for mounting to the pointer. Moreover, the use of the film material allows for the simplified printing of a graphic symbol on the cap that would not be feasible or practical for the use of other more rigid materials. 
         [0008]    Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
         [0009]    These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic view of an example instrument panel for a motor vehicle. 
           [0011]      FIG. 2  is a cross-section of an example gauge. 
           [0012]      FIG. 3  is a cross-sectional view through a pointer assembly for the example gauge. 
           [0013]      FIG. 4  is an exploded view of the pointer assembly. 
           [0014]      FIG. 5  is a schematic view of a method of assembling an example gauge assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 1  schematically illustrates a dashboard  10  for a motor vehicle. The dashboard  10  includes an instrument panel  12  that includes a plurality of gauges  14  and dials  16 . The gauges  14  communicate information indicative of vehicle operating parameters to vehicle operator. A pointer assembly  15  is included for the gauge  14  that rotates about an axis A to point to a specific portion of the graphics provided in each of the gauges  14  to indicate a current value of an operating condition. 
         [0016]    Referring to  FIG. 2 , the example gauge  14  includes the pointer assembly  15  that rotates about an axis A. The pointer assembly  15  includes a pointer  24 , a pointer cap  48  and a pointer shroud  50 . The pointer assembly  15  rotates about the axis A and points to specific graphics  22  that are supported on a gauge surface  20 . 
         [0017]    The gauge surface  20  is supported within a housing  18 . The housing  18  also supports a printed circuit board  32  and a stepper motor  34 . The stepper motor  34  is housed and supported on the circuit board  32  along with a light source  38 . The stepper motor  34  rotates a clear shaft  36  about the axis A. In this example, the shaft  36  is transparent to allow for the propagation of light emitted from the light source  38 . Although the example stepper motor  34  and light source  38  are shown supported on a common circuit board  32 , they may be orientated and supported within the housing  18  by different structures. A light housing  35  blocks light propagation to the outer surface surrounding the light source  38 . 
         [0018]    Light from the light source  38  is transmitted through the stepper motor shaft  36  into a pointer shaft  30 . Light enters the pointer shaft  30  and a portion of the pointer body  28  that includes a first reflective surface  40 . Light  44  communicated to the first reflective surface  40  are directed into the pointer needle  26 . Some of the light  46  is reflected through the first reflecting surface  40 . The light  46  reflected through the first reflective surface  40  can create a bright spot that is not desirable and, therefore, the pointer cap  48  is provided and attached to the pointer  24 . 
         [0019]    The cap  48  blocks light transmitted along the axis A to prevent bright spots from being visible to an operator. A shroud  50  is assembled to a bottom portion of the pointer  24  to further block and shield light that may be emitted in a direction that is not desirable. 
         [0020]    Referring to  FIGS. 3 and 4  with continued reference to  FIG. 2 , the example pointer assembly  15  includes the pointer cap  48  and the pointer shroud  50 . The pointer cap  48  is fabricated from a thin film material or applique to provide a substantially thin and lightweight cap  48 . The pointer shroud  50  disposed on a bottom surface  74  of the pointer  24  is also fabricated from a thin film material. The film material may be common to or similar to the material utilized for fabricating the gauge surface  20 . Moreover, the film material may be translucent to provide for the propagation of light to a printed graphic. The film material may also reflective to block light propagation. 
         [0021]    In this example, both the cap  48  and the shroud  50  are fabricated from a polycarbonate film material to provide a substantially thin lightweight cap  48  and shroud  50 . The cap  48  is attached to the pointer  24  through the use of an adhesive material  54 . 
         [0022]    The adhesive material  54  is applied to a pointer surface  56  and adheres the cap  48  to the pointer  24 . The shroud  50  is also mounted to the pointer  24  with adhesive  54 . The cap  48  is adhered to surfaces  42  disposed on the pointer body  28 . 
         [0023]    Previous configurations included press fit pins that fit into openings defined within the pointer. These pins required substantially rigid tolerances and were susceptible to breakage. Moreover, the pins required the fabrication of the cap  48  from more expensive materials. Accordingly, the use of a polycarbonate film simplifies assembly and attachment of the cap  48  and the shroud  50  to the pointer  24 . 
         [0024]    In one example, the polycarbonate cap  48  further provides a feature that is not feasible when other more expensive materials are utilized. In this example, the cap  48  includes a printed graphic portion  58  that is illuminatable by light communicated through the pointer  24 . The graphic  58  can be printed on the polycarbonate film material to provide an illuminatable graphic or design within the cap  48 . 
         [0025]    Referring to  FIG. 5  with continued reference to  FIGS. 3 and 4 , a method of assembly of the pointer  15  and gauge assembly  14  is schematically disclosed and includes an initial step of providing a polycarbonate film sheet material  72 . The polycarbonate material is easily formed through thermal forming and other known manufacturing processes that are relatively inexpensive and reduce complexity and cost. 
         [0026]    The polycarbonate film material  72  in this example is thermal formed as is schematically indicated at  64  to provide the desired shape of the cap  48  and the corresponding shroud  50 . A thermal forming process may be executed as is known by those skilled in the art. 
         [0027]    In this example, the cap  48  is then moved to a processing station  66  where a graphic symbol  58  is printed to a visible surface. The film material utilized for this example is translucent and provides for the propagation of light through a printed graphic symbol  58 . The graphic printing process can be utilized as is known in the art and is simplified by the use of the polycarbonate film material  72 . 
         [0028]    Once the cap  48  and shroud  50 , they may be assembled to the pointer  24 . Because the polycarbonate film material is substantially lightweight, it may be attached to the pointer  24  using simplified techniques. In this example, the simplified technique includes application of an adhesive  54  to adhere the cap  48  to surfaces  56  of the pointer  24 . 
         [0029]    The shroud  50  is similarly attached to the bottom surface  74  of the pointer  24 . The adhesive utilized for attaching the polycarbonate cap  48  and shroud  50  are as known in the art and do not require special characteristics as the use of the polycarbonate material simplifies this assembly and attachment process. Moreover, the use of the adhesive material simplifies the attachment configuration by eliminating the need for specially formed and molded mating features. All that is required is that the pointer assembly includes the flat surface  56  for receiving adhesive  54  and the corresponding cap  48 . Once the cap and pointer assembly  24  are complete, they may be assembled into the gauge assembly  14  as is indicated at  70 . 
         [0030]    Accordingly, the example pointer assembly  15  includes a polycarbonate cap and shroud that simplifies assembly and allows for the use of adhesive for mounting to the pointer. Moreover, the use of the film material allows for the simplified printing of a graphic symbol on the cap that would not be feasible or practical for the use of other more rigid materials. 
         [0031]    Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure.