Abstract:
An attachment assembly provides quick attachment of an automotive antenna unit or other object to the exterior of a vehicle. A single worker is able to install the antenna unit or other object with one downward push from the exterior without the need for tools. The attachment assembly also includes an anti-rotation feature to prevent rotation. The attachment assembly can only be removed from the interior, rendering the attachment assembly tamper resistant from the exterior. The attachment assembly can also be mounted on vehicles with various panel thicknesses.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
         [0001]    N/A  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    N/A  
         BACKGROUND OF THE INVENTION  
         [0003]    Automobiles and other vehicles typically include an antenna mounted on the body of the vehicle. The antenna includes a housing unit that mounts to the exterior with an attachment that extends through an opening to the interior of the vehicle. In the installation of the antenna, an automotive assembly worker must work in a confined space in the interior of the vehicle and must use one or more tools. In some cases, assistance from another worker is also required.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention provides an attachment assembly that provides quick attachment of an automotive antenna unit or other object to the exterior of a vehicle. A single worker is able to install the antenna unit or other object with one downward push from the exterior through an opening in the vehicle panel without the need for tools. The attachment assembly also includes an anti-rotation feature to prevent rotation once installed. The attachment assembly can only be removed from the interior, rendering the attachment assembly tamper resistant from the exterior. The attachment assembly can also be mounted on vehicles with various panel thicknesses.  
           [0005]    More particularly, the attachment assembly includes a base assembly fixed to a lower surface of the object. The base assembly includes a shaft member that extends through the opening in the vehicle panel. An expandable member on the shaft member includes a plurality of resilient members that abut against an interior surface of the panel. The resilient members are compressible to pass through the opening in the panel during installation. A retaining member retains the expandable member on the shaft member with the resilient members in abutment with the interior surface of the panel after installation. A spacer member also disposed on the shaft member biases the expandable member against the retaining member with a gap between the expandable member and the lower surface of the object. The gap is sized to receive the panel of the vehicle after the installation procedure. In this way, panels of various thicknesses can be accommodated by an appropriately sized spacer member. If necessary, a final adjustment can be made to the retaining member after installation. A keying feature is provided between the expandable member and the base assembly to prevent rotation of the attachment assembly.  
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0006]    The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:  
         [0007]    [0007]FIG. 1 is a side view of an automotive attachment assembly in conjunction with an antenna unit according to the present invention;  
         [0008]    [0008]FIG. 2 is an exploded view of the attachment assembly and antenna unit of FIG. 1;  
         [0009]    [0009]FIG. 3 is an exploded view of the attachment assembly of FIG. 1;  
         [0010]    [0010]FIG. 4 is a side view of the attachment assembly of FIG. 1;  
         [0011]    [0011]FIG. 5 is a cutaway plan view of a vehicle panel for use with the attachment assembly and antenna unit of FIG  1 .  
         [0012]    [0012]FIG. 6 is an exploded view of a further embodiment of an attachment assembly;  
         [0013]    [0013]FIG. 7 is a side view of the attachment assembly of FIG. 6; and  
         [0014]    [0014]FIG. 8 is a cutaway plan view of a vehicle panel for use with the attachment assembly of FIG. 6. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]    An antenna attachment assembly  10  according to the present invention is illustrated more fully in FIGS.  1 - 5  in conjunction with an antenna unit  12 . The attachment assembly  10  is fixed to and extends from the antenna unit  12  and extends through an opening  14  in a panel  16  of a vehicle body. The attachment assembly  10  includes an expandable member  18  that is biased against the interior surface  20  of the panel  16 , thereby fixing the attachment assembly  10  and antenna unit  12  to the vehicle, as discussed further below.  
         [0016]    In the illustrated embodiments, the antenna unit  12  is illustrated as a radome cover  22  for a GPS or satellite antenna. It will be appreciated that the attachment assembly of the present invention may be used with any type of antenna and associated cover or base unit, such as an AM/FM antenna, or with any other device or object that is intended to be affixed to an exterior panel of the vehicle.  
         [0017]    In the illustrated embodiment, the unit  12  has a lower surface  24  that is supported on the exterior surface  26  of the vehicle panel  16  over the opening  14  in the panel. A cable  28  from the unit  12  extends through the lower surface  24  of the unit and through the opening  14  in the panel  16  for connection to other components within the vehicle, as known in the art. A perimeter gasket  30  with an opening  32  therein fits between the lower surface  24  of the unit  12  and the exterior surface  26  of the panel  16 . The gasket  30  seals the opening  14  against leaks and compensates for thickness and contour fluctuations in the panel  16 . Keying features  34  extend from the unit  12  and the gasket  30  into a smaller opening  36  in the panel  16 , as known in the art.  
         [0018]    In a first embodiment, the attachment assembly  10  includes a base assembly  40  that is fixed to and extends from the lower surface  24  of the antenna unit  12 . The base assembly  40  includes a base plate  42  having a plurality of radially extending tabs  44  located about the circumference of the base plate. The tabs fit within the opening  14  in the panel  16 . Three tabs  44  are suitable, although any desired number may be used. The base assembly  40  may be integral with or fixed to the unit  12  in any suitable manner, such as with screws or adhesive. The base assembly  40  also includes an externally threaded hollow shaft  46  extending downwardly from the base plate  42 . The shaft includes one or more key slots  48  along its length, discussed further below. The cable  28  from the unit  12  passes through the hollow interior  50  of the shaft  46 .  
         [0019]    When installed on a vehicle, the base assembly  40  extends through the opening  14  in the panel  16 . The expandable member  18 , such as a snap ring, fits over the externally threaded shaft  46 . A retaining member  54 , such as an internally threaded jam nut, retains the expandable member  18  on the base assembly and biases the expandable member against the interior surface  20  of the panel  16 . The nut preferably includes a self-locking fastener element  58 , such as a polyester or nylon element, applied to the threads at an interior location to prevent slippage, as known in the art. The fastener element should not impede engagement of the nut onto the threads of the shaft.  
         [0020]    In the embodiment shown, the snap ring comprises an annular washer portion  60  and a plurality of upstanding, resilient members such as fingers  62  that, in the installed position, expand radially outwardly and at their tips  64  press against the interior surface  20  of the panel  16 . The snap ring is preferably stamped and formed from a sheet material having a thickness, hardness, and other properties selected to provide an appropriate amount of resiliency to the fingers, as may be readily determined by those of skill in the art. A metal material, such as a 30 gage stainless steel, is suitable, although an appropriate plastic or composite material may be used if desired. Preferably, a stability washer  66  is provided above and an anti-torsion washer  68  is provided below the annular washer portion  60  to stiffen and support the washer portion and protect the washer portion from distortion. Generally, the washers are stamped from a thicker sheet material than the snap ring, such as a 20 gage stainless steel. Both washers and the snap ring include one or more inwardly facing tabs or keys  70  that align with and fit within the key slots  48  on the threaded shaft  46 . When fitted within the key slots, the keys prevent the expandable member  18  from rotating with respect to the unit  12 .  
         [0021]    The attachment assembly also includes a spacer member  72  such as a compression spring that allows for multiple preset distances to accommodate various panel thicknesses. The compression spring exerts a downward bias on the snap ring against the upward force exerted by the jam nut. The height of the compression spring is set by tightening the jam nut so as to achieve the desired distance or gap (d) between the top of the snap ring fingers and the base plate. Upon installation, the vehicle panel fits within this gap. If necessary, the size of the compression spring may be selected to achieve the desired gap size, depending on the thickness of the panel.  
         [0022]    Assembly requires a downward push of the antenna unit  12  and the attachment assembly  10  through the opening  14  in the panel  16 . As the attachment assembly is inserted through the opening in the panel, the resilient fingers  62  of the snap ring compress radially inwardly. The tips  64  of the fingers extend within arcuate regions  74  between the tabs  44  of the base plate  42 . Once the snap ring passes fully through the opening  14 , the fingers spread radially outwardly. The tips of the fingers, which are preferably bent inwardly, abut against the interior surface  20  of the panel  16 , thereby locking the attachment assembly place. If necessary, any final adjustments can be made by rotating the jam nut.  
         [0023]    In a further embodiment, illustrated in FIGS.  6 - 8 , a further anti-rotation keying mechanism is provided. The opening  14  in the panel  16  includes one or more recesses  80  spaced to provide a single orientation. The radially extending tabs  44  on the base plate  42  are aligned with the recesses  80 . The tabs fit within the recesses to prevent rotation of the assembly within the opening. Upstanding arms  82  are provided on the lower anti-torsion washer to guide the attachment assembly through the opening  14  during installation. The anti-rotation keying mechanism may be provided in place of or in addition to the keying features  34  utilizing the second opening  36  provided with the antenna unit  12 .  
         [0024]    It will be appreciated that other variations of the above embodiments are possible. For example, the expandable member and the retaining member may be formed as an integral member. The invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.