Abstract:
A center stack for an instrument panel of a motor vehicle. The center stack includes a front plate having an exposed surface with a first surface finish and a back plate having a visible portion uncovered by the front plate. The front plate has at least one opening extending through the exposed surface for accessing at least one operational feature of the motor vehicle. The visible portion of the back plate has a second surface finish that differs from the first surface finish of the front plate. The back plate may include a flex joint that permits the visible portion of the back plate to move relative to an adjacent non-visible portion covered by the front plate.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to motor vehicle interior components and, more particularly, to center stacks for use in the passenger cabin of a motor vehicle. 
     BACKGROUND OF THE INVENTION 
     Instrument panels or dashboards for motor vehicles, such as automobiles, generally include modules integrated together and installed as a single unit into a forward portion of a vehicle passenger cabin. The “center stack” region of the instrument panel supports various controls and interior features. Conventional center stacks may include sound system controls, climate controls for the heating, ventilation, and air conditioning (HVAC) system, and vents or outlets that exhaust air supplied from the vehicle&#39;s HVAC system, among other controls and features. Components, such as the sound system, are mounted in the center stack proximate to the controls. The center stack is closed out with a front plate or trim bezel having a front side with Class A surfaces suitable for a vehicle interior that are visible to occupants of the passenger cabin. 
     Because stacking space is limited, integrated center stacks represent an evolution in center stack technology in which the actual components, like the sound system and the HVAC electronics, are not supported by the center stack. Instead, the components are mounted remote from the center stack at other locations inside the vehicle. The controls for the components remain associated with the center stack and are accessible to the occupants seated in the front of the passenger cabin. The controls are connected with the actual components by a flex cable, flat wire, or transmitted radio frequency signals to increase the stacking space. The individual controls may include circuit boards mounted to the center stack. Integrated center stacks, which are also conventional, are more compact than earlier generation conventional center stacks that provided support for the components themselves. Integrated center stacks are also closed out with a front plate or trim bezel having a Class A surface visible to occupants of the passenger cabin. 
     Front plates are typically single-piece constructions that may include outlets for the HVAC system defined in the front plate. Different or contrasting finishes may be applied to different visible surfaces or regions of the front plate. For example, one region on the front plate may be painted and an adjacent region on the front plate may have a wood grain finish from, for example, a laminate. If different or contrasting finishes are applied on different regions of the front plate, a transition zone or paint ditch is required along the boundary across which the finish changes. Alternatively, separate bezels may be positioned to cover the regions with contrasting finish to achieve a suitable finish transition. 
     It would be desirable to provide an improved center stack that permits the visible surface finish on the center stack to differ or contrast between different regions without the use of a paint ditch or another expensive feature. 
     SUMMARY OF THE INVENTION 
     In an embodiment of the present invention, a center stack for an instrument panel of a motor vehicle includes a front plate having an exposed surface with a first surface finish and a back plate having a visible portion uncovered by the front plate. The front plate has at least one opening extending through the exposed surface for accessing an operational feature of the motor vehicle. The visible portion of the back panel has a second surface finish differing from the first surface finish of the front plate. 
     In another embodiment of the present invention, a center stack for an instrument panel of a motor vehicle includes a front plate having an exposed surface and a back plate having a central panel covered by the front plate. The front plate includes at least one opening extending through the exposed surface for accessing an operational feature of the motor vehicle. The back plate further includes a visible portion uncovered by the front plate when the front plate is assembled with the back plate and a flex joint joining the visible portion with the central panel. The flex joint permits the visible portion to move relative to the central panel. 
     The invention therefore provides a center stack assembled from two components, a front plate and a back plate, with two different or contrasting surface finishes and no gap (e.g., no paint ditch) between the different or contrasting surface finishes. To that end, the structural back plate is integrated with outboard bezels, which allows these outboard bezels to have a different finish than the center stack trim plate. Combining the bezels with the back plate eliminates the need for additional separate bezels required to achieve a suitable finish transition. 
     These and other objects and advantages of the invention shall become more apparent from the accompanying drawings and description thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention. 
         FIG. 1  is an exploded view of a composite center stack in accordance with the present invention; 
         FIG. 2  is front view of the assembled center stack of  FIG. 1 ; 
         FIG. 3A  is a cross-sectional view taken generally along line  3 A- 3 A in  FIG. 2 ; 
         FIG. 3B  is a cross-sectional view similar to  FIG. 3A  depicting the peripheral wings in a deflected condition; and 
         FIGS. 4 and 5  are cross-sectional views similar to  FIG. 3A  in accordance with alternative embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIGS. 1 and 2 , a composite center stack  10  for a vehicle is an assembly that includes a front plate  12  and a structural back plate  16  having a central panel  13  with a hidden outer surface  18  that is covered by front plate  12  in an assembled condition. The front plate  12  has a visible outer surface  14  and a hidden inner surface  11  ( FIG. 3A ) that confronts the hidden outer surface  18  of central panel  13  after assembly. Flanking the hidden outer surface  18  of the back plate  16  is a laterally-spaced pair of lateral portions having the form of appendages or wings  17 ,  19 . Each of the wings  17 ,  19  projects from the central panel  13  to define a channel that receives the front plate  12 . Each of the wings  17 ,  19  also has a corresponding visible outer surface  15 ,  21  and is integrally connected with the central panel  13  to form a one-piece unitary structure so that hidden outer surface  18  is continuous with visible outer surfaces  15 ,  21 . 
     Front plate  12  includes a plurality of laterally-spaced circular openings  20 ,  24 ,  26 , each of which receives one of a corresponding plurality of controls, in the form of knobs  22 ,  28 ,  30 , for controlling the operation of, for example, a stereo system (not shown). Vertically spaced from openings  20 ,  24 ,  26  are openings  32 ,  34 ,  36 , and  38  arranged in a vertically stacked fashion. Opening  32  receives a module or panel  40  that may include, for example, a loading slot for compact disks. Opening  34 , which is positioned below opening  32 , receives, a module or panel  42  bearing, for example, additional controls for the stereo system. Opening  36 , which is positioned below opening  34 , receives, for example, an open storage bin  44 . A display  48  covered by a separate lens  50  and an accompanying bank of controls  52  is positioned in a curved recess  54  defined along an upper peripheral edge of the front plate  12 . Of course, the number of openings in front plate  12  and the specific type of structural elements filling each opening are matters of design choice as understood by a person of ordinary skill in the art. 
     The panels  28 ,  30 ,  40 ,  42 , each of which may include a circuit board with interconnected electronics suitable for functional operation and which are illustrated as being strapped together for ease of assembly with front plate  12 , are mechanically attached to and supported by the front plate  12 . Each of the panels  28 ,  30 ,  40 ,  42  may include various operational features that either display or indicate information, like displays, gauges, and indicators, and that regulate operation of a component, such as controls like switches, dials, knobs, and buttons. 
     The front plate  12  closes out the center stack  10  and is secured to the back plate  16  with conventional fasteners. Integrally molded with the front plate  12  are posts  45  that project from the hidden inner surface  11  of the front plate  12  opposite to visible outer surface  14  and provide a structure  47  capable of being coupled with these fasteners. Other integrally-molded fastening structures  47  provided on the hidden surface  11  of front plate  12  may be used, along with integrally-molded fastening structures  49 , such as clip towers, on the back plate  16 , to mount the center stack  10  to the instrument panel. 
     Each of the lateral wings  17 ,  19  includes one of a pair of openings  56 ,  58  that are coupled by ducting with the vehicle&#39;s HVAC system. These openings  56 ,  58  serve as vents that discharge air into the passenger cabin of the vehicle. Each of the openings  56 ,  58  is filled by an HVAC outlet  61 ,  63  with movable slats  60 ,  62 , respectively, adjustable in orientation for directing discharged air. Additional panels  64 ,  66  bearing controls are positioned in two additional openings  68 ,  70  that also flank the hidden outer surface  18  at a location spaced vertically from the corresponding one of openings  56 ,  58 . These panels  64 ,  66  may be, for example, individualized HVAC controls for the driver and passenger of the motor vehicle. 
     The front plate  12  and back plate  16  of center stack  10  may be injection molded, which readily accommodates various features like undercuts, die locks, ribs, bosses, and attachment features in the construction. Injection molding processes also permit the introduction of inserts, such as an in-mold appliqué to provide a visible decorative finish on the front plate  12  or a bezel to define an opening in the back plate  16 , into the mold before molding. Front plate  12  and back plate  16  may be formed from a relatively rigid thermoplastic, such as a polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blend that may be either neat or filled. 
     A Class A surface finish is applied to portions of the back plate  16  before assembly with the front plate  12 . Specifically, the visible outer surface  15 ,  21  of each of the wings  17 ,  19  may be painted or an appliqué may be strategically inserted into the mold before the injection molding process forming back plate  16  so that the injected molten thermoplastic overmolds the appliqué. Similarly, a Class A surface finish is applied to the visible outer surface  14  of the front plate  12 . These surface finishes on visible surfaces  14 ,  15  and  21  are class A surface finishes. The surface finish on visible outer surface  14  will typically differ or contrast from the surface finish on visible outer surfaces  15 ,  21 , although the invention is not so limited. For example, the surface finish on visible outer surface  14  may be supplied by an appliqué while the surface finish on visible outer surfaces  15 ,  21  may be a coating of paint. The result is that the surface finishes on the visible outer surface  14  of the front plate  12  and the visible outer surfaces  15 ,  21  of the back plate  16  do not match. 
     As used herein, terms like “front”, “rear”, “inner” and “outer” are used to provide a convenient frame of reference. For example, outer surfaces are understood to be visible to an occupant of the vehicle&#39;s passenger cabin and inner surfaces are understood to be hidden from the view of the occupant. Alternative reference frames may be used to provide an equivalent description. 
     The assembled center stack  10  may be a separate substructure of an instrument panel assembly or may be integral with an instrument panel positioned inside the vehicle&#39;s passenger cabin. The instrument panel or panel assembly (not shown) is typically reinforced with metal brackets or cross-car beams. 
     The front plate  12  includes a laterally-spaced pair of side peripheral edges  72 ,  74  that connect a top edge  76  with a bottom edge  78 . Defined at the interfaces between the side peripheral edges  72 ,  74  and the hidden outer surface  18  are slip planes that permit lateral adjustment of the front plate  12  as necessary to fit front plate  12  and back plate  16 . As a result, the position of the front plate  12  can be varied laterally without degrading the appearance of the assembled center stack  10 . The hidden outer surface  18  of the back plate  16  has a width measured between the juncture of hidden outer surface  18  with the wings  17 ,  19  that is greater than the width of the front plate  12  to permit the lateral adjustment. The perceived visual appearance of the vertical gaps between the side peripheral edges  72 ,  74  of front plate  12  and the wings  17 ,  19  does not change because of the presence of the slip planes. 
     With reference to  FIGS. 3A and 3B , a flex joint  80  is defined in the material forming the back plate  16  at the junction between the central panel  13  and wing  17 . A similar flex joint, although not shown, is defined in the material forming the back plate  16  at the junction between the central panel  13  and wing  19 . The flex joint  80  permits the wing  17  to flex and move relative to the central panel  13 , which permits a tight finish with the adjacent portion of the instrument panel  65 , when the center stack  10  is installed in the vehicle, without damaging the material of the back plate  16  at a visible location. 
     Flex joint  80  extends vertically in the transition region between the central panel  13  and the wing  17 . The flex joint  80  includes two legs or walls  82 ,  84  projecting away from a base wall  86 . In the unbiased state shown in  FIG. 3A , the walls  82 ,  84  diverge from base wall  86  so that a V-shaped gap or recess is defined between the walls  82 ,  84 ,  86  and a second V-shaped gap or recess is defined between wall  84  and an adjacent flange  88  of wing  17 . The two V-shaped recesses open in opposite directions and neither is visible in the assembled center stack  10 . A flange  89  extends from the hidden surface  11  of front plate  12  to contact the back plate  16  and thereby space the face and back plates  12 ,  16 . 
     When the center stack  10  is installed, a force is applied to the wing  17 , as diagrammatically indicated by single-headed arrow  85 , that causes the wing  17  to rotate along flex joint  80  relative to the stationary and rigid central panel  13 . The rotation causes flange  88  to move closer to flange  89  of the front plate  12 , as indicated by single-headed arrow  87 . The rotation of wing  17  is accommodated by the flex joint  80 , as wall  84  moves toward wall  82  so as to close or collapse the intervening V-shaped recess and the flange  88  moves toward wall  84  to close or collapse the other V-shaped recess. The side peripheral edge  72  of the front plate  12  is stationary relative to the moving flange  88 . While experiencing a typical amount of flexure, the visible outer surface  14  of the front plate  12  near the side peripheral edge  72  overlaps with the visible outer surface  15  on flange  88 . As a result, there is no visible gap between the peripheral edge  72  of front plate  12  and back plate  16  when a typical amount of flexure is experienced by wing  17  relative to central panel  13 . 
     If the wings  17 ,  19  projected laterally from the front plate  12  instead of the back plate  16 , the Class A surface finish applied to the visible outer surfaces  14 ,  15 ,  21  could be degraded by flexing during installation of the center stack  10 . Therefore, mounting the wings  17 ,  19  to the back plate  16  in accordance with the present invention is advantageous in this regard. If the back plate  16  is painted to provide the Class A surface finish on the visible outer surfaces  15 ,  21 , any overspray on the hidden outer surface  18  of center panel  13  is hidden by the front plate  12  in the assembly so that masking is not required during the painting operation. The center panel  10  may be fabricated by injection molding the front plate  12  in a first injection molding tool and injection molding the back plate  16  in a second injection molding tool. The wings  17 ,  19  are formed in the injection molding process forming the back plate  16 , so that a separate injection molding process and tool is not required. 
     With reference to  FIG. 4  in which like reference numerals refer to like features in  FIG. 3A  and in accordance with an alternative embodiment of the invention, a vertically-extending flex joint  90  couples the central panel  13  and the wing  17  to define the transition region. Flex joint  90  includes two legs  92 ,  94  that connect flange  88  with the central panel  13 . The legs  92 ,  94  join at a corner  96  and leg  92  joins the central panel  13  along a corner  98 . An outwardly directed force applied to wing  17  causes flange  88  to move toward flange  89  as in direction  87 . The movement is accommodated by movement of the legs  92 ,  94  along corners  96 ,  98 . 
     With reference to  FIG. 5  in which like reference numerals refer to like features in  FIGS. 3A and 4  and in accordance with an alternative embodiment of the invention, a vertically-extending flex joint  100  couples the central panel  13  and the wing  17  to define the transition region. Flex joint  100  includes a thinned wall or region  102  that joins the central panel  13  with the flange  88  of wing  17 . The thinned region  102  is thinned relative to the full thickness of the central panel  13 . An outwardly directed force applied to wing  17  causes flange  88  to move toward flange  89  as in direction  87 . The movement is accommodated by movement of flexing of the thinned region  102  as the thinned region  102  yields more easily than the adjacent portions of central panel  13  and flange  88 . The front plate  12  completely covers the flex joint  100  so that it is not visible to an individual inside the passenger cabin of the motor vehicle. 
     Flex joints  80 ,  90 ,  100  may be used at other locations and for other purposes in the construction of interior components for a motor vehicle in which one portion of a component must flex relative to another portion of the component. 
     While the invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants&#39; general inventive concept.