Patent Publication Number: US-7212168-B2

Title: Quick-attach automotive antenna mounting assembly

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 10/164,117 filed Jun. 5, 2002 entitled “Quick-Attach Automotive Antenna Mounting Assembly”, now U.S. Pat. No. 7,004,666, incorporated herein by reference, which is a continuation-in-part U.S. patent application Ser. No. 09/972,807, filed Oct. 9, 2001, entitled “Quick-Attach, Single-Sided Automotive Antenna Attachment Assembly”, now U.S. Pat. No. 6,762,727, the disclosure of which is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     N/A 
     BACKGROUND OF THE INVENTION 
     In many situations, it is necessary to attach a device to a panel or other support structure. One example is the attachment of an antenna, such as a Global Positioning System (GPS) antenna or cellular antenna to an automobile roof or trunk lid. When such devices are installed on an assembly line, it is important that the device can be accurately and quickly secured to the panel. It is also important that the device be self-contained, so as to eliminate the need for multiple parts or two-handed (or multiple person) operation to install the device. Further, it is important that the installation be as simple as possible with few operational steps. In some applications, there is an additional requirement that the device be properly oriented relative to the panel. 
     There are numerous known apparatus and processes to attach a device to a panel. In most of those known procedures, the use of both hands, or multiple people, is required for the installation because the device is positioned on one side of the panel and the fastening means is operated from the opposite side of the panel. In addition, most installations of known devices require multiple steps, or the apparatus involves the use of many, often small parts, such as nuts, washers, bolts, screws, or the like. These deficiencies result in a time consuming and awkward installation. 
     SUMMARY OF THE INVENTION 
     The present invention provides an attachment assembly that provides quick attachment of an object, such as an automotive antenna unit, to a panel or other support surface, such as an exterior panel 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. 
     More particularly, the attachment assembly includes a base assembly fixed to an object to be mounted to a panel. The base assembly includes a shaft member that extends through an opening in the 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. 
     In a further embodiment, the invention provides an attachment assembly comprising a base member having a mounting stud, a retaining cap disposed on the mounting stud, the retaining cap comprising a plurality of retaining fingers, wherein the retaining fingers cooperate with the stud such that, upon axial movement of the retaining cap toward the base member, the retaining fingers radially outwardly expand and apply clamping pressure against the panel. 
     In a preferred embodiment, a snap collar is disposed on the mounting stud near the base member, the snap collar having at least one resilient leg aligned along a longitudinal axis of the stud. The leg contacts the interior of the panel to prevent movement of the base away from the panel. 
     In yet another aspect, the invention provides a process of mounting an object to a panel comprising the steps of attaching an object to an attachment assembly according to the invention and installing the attachment assembly to a panel. 
     These and other aspects of the invention will become apparent on a further consideration of the specification, drawings and the appended claims. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a side view of an automotive attachment assembly in conjunction with an antenna unit according to the present invention; 
         FIG. 2  is an exploded view of the attachment assembly and antenna unit of  FIG. 1 ; 
         FIG. 3  is an exploded view of the attachment assembly of  FIG. 1 ; 
         FIG. 4  is a side view of the attachment assembly of  FIG. 1 ; 
         FIG. 5  is a cutaway plan view of a vehicle panel for use with the attachment assembly and antenna unit of  FIG. 1 ; 
         FIG. 6  is an exploded view of a further embodiment of an attachment assembly; 
         FIG. 7  is a side view of the attachment assembly of  FIG. 6 ; and 
         FIG. 8  is a cutaway plan view of a vehicle panel for use with the attachment assembly of  FIG. 6 . 
         FIG. 9  is a sectioned elevation view of a further embodiment of an attachment assembly according to the invention; 
         FIG. 10  is a perspective view of the underside of the base of the attachment assembly of  FIG. 9 ; 
         FIG. 11  is an isometric view of the mounting stud of the attachment assembly of  FIG. 9 ; 
         FIG. 12A  is plan view of the snap collar of the attachment assembly of  FIG. 9 ; 
         FIG. 12B  is a side elevation view of the snap collar of  FIG. 12A ; 
         FIG. 13A  is a plan view of the retaining cap of the attachment assembly of  FIG. 9 ; 
         FIG. 13B  is a side elevation view of the retaining cap of  FIG. 13A ; and 
         FIGS. 14A ,  14 B,  14 C and  14 D are a series of partial cross-sectional views of the attachment assembly particularly illustrating the process of attaching an object to a panel. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     An antenna attachment assembly  10  according to a first embodiment of 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. 
     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 a panel. 
     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. 
     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 . 
     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. 
     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 . 
     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. 
     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. 
     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 . 
     A further embodiment of an attachment assembly is shown in  FIGS. 9–14D  in conjunction with an antenna unit  110  having a lens  112 . The attachment assembly includes a base assembly  114  including a base plate  128 . A shaft member or mounting stud  116  projects from the bottom of the base plate  128 . Preferably, the mounting stud  116  is formed integral with the base plate  128 . In use, the mounting stud  116  is disposed in an aperture  101  in a panel  100  (see  FIGS. 14A–14D ) with the base plate  128  placed against the outer surface of the panel. A threaded stud  126  projects from the mounting stud  116 . Disposed over the mounting stud  116  are an expandable member, such as a retaining cap  122 , and a spacing member, such as a snap collar  120 . These elements, in combination with a retaining member, such as a nut  124  on the threaded stud  126 , cooperate to secure the base assembly  114  to the panel  100 , as is explained in greater detail below. 
     In the embodiment shown, the plate  128  is provided with a plurality of openings  129 . These openings facilitate attachment of the plate  128  to the object being mounted, such as the antenna lens  112  illustrated. The number, size and location of such openings are determined based on the particular application. In some applications, such as in certain automobile antennas, it is necessary or desirable to properly orient the device relative to the panel. In such circumstances, a keying feature such as an orientation stud  117  may be provided on the base assembly that projects through a suitable aperture  102  in a panel  100 . 
     A gasket  118 , shown in FIGS.  9  and  14 A– 14 D, is disposed against the bottom surface of the base plate  128 . The gasket  118  seals the base assembly  114  to the panel  100 . The gasket  118  may not be required or desirable in all applications. It is particularly desired to employ a gasket in automotive applications or other applications where the exterior of the panel is exposed to the out of doors. Any suitably shaped gasket  18  of suitable material may be employed to advantage. When the attachment assembly of the invention is affixed to a panel, the gasket  118 , if used, is compressed between the panel and the base plate  128 . Accordingly, the materials and design of the gasket  118  are selected to permit such compression to occur. 
     Referring  FIG. 10 , the base plate  128  as illustrated has an egg or oval shape with the mounting stud  116  located in approximately the center of the plate  128 . For clarity, the threaded stud  126  of mounting stud  116 , nut  124 , and retaining cap  122  are not shown in  FIG. 10 . The size and shape of the plate and position of the mounting stud are determined by the intended use. It is most preferred that the plate  128  have generally the same contours of the panel to which it is to be attached to provide a smooth, tight contact between the panel and the base plate (or gasket where a gasket is employed). Thus, if the base assembly were intended to be attached to a curved panel, the base plate would be designed with the same curvature as the curved panel. Preferably, the base assembly  114  is of die cast construction, although the invention is not limited thereto. Machined or molded constructions can also be used to advantage. 
     With particular attention to  FIGS. 10 and 11 , the mounting stud  116  is a generally cylindrical shaped member having a centrally located body section  130  disposed intermediate the base  132  of the stud (that is, the point where the mounting stud  116  emerges from the base plate  128 ) and the tip  134  of the stud  116 . The body section  130  forms an annular recess or notched area  136  at the base  132  of the stud  116 , as best seen in  FIG. 11 . The body section  130  is tapered or flared outwardly from the tip  134  toward the base  132  of the stud  116 , such that the diameter of the body  130  is greatest where the body section  130  joins the annular recess  136 . The tip  134  of the stud  116  is beveled or chamfered toward the threaded stud  126 . As such, the mounting stud, when viewed in cross-section, has a double bevel configuration. 
     The mounting stud  116  is also provided with at least one boss member  138  outwardly projecting from the stud  116 . In a preferred embodiment, as shown in  FIG. 11 , the stud  116  is provided with three such boss members  138   a ,  138   b  and  138   c , one positioned in each of three quadrants along the circumference of the stud  116 . The remaining quadrant of the stud  116  contains a notch  140  that is oriented along the longitudinal axis of the stud  116 . The notch  140  is coextensive with a through-hole  142  in the base plate  128 . The notch  140  and through-hole  142  permit electrical wiring or coaxial cables or other necessary electromechanical connections to be made to the antenna or other device being attached to the panel. Of course, if no such connections are needed, the notch  140  and through hole  142  can be eliminated. Additional notches may be provided in the body section  130  and longitudinally aligned with bosses  138   a  and  138   c , which are located on opposite sides of the body section  130  of stud  116 . See, for example, the notches  144  aligned with bosses  138   a  and  138   c  in  FIG. 9 . 
     The snap collar  120  is shown in  FIGS. 12A and 12B . The snap collar  120  comprises a split ring portion  146  having a pair of resilient legs  148  extending therefrom in a direction generally perpendicular to the plane of the split ring portion  146 . The legs  148  are spaced approximately 180 degrees from one another. Each of the legs  148  comprises a straight section  150  and a cantilever section  152 . A tab  153  extends from each cantilever section, forming a notch surface  155  with the cantilever section. The cantilever section  152  of each leg  148  is resiliently movable toward straight section  150  such as, for example, when the stud  116  is inserted into an aperture in a panel, and then returns to its neutral position. Cantilever sections  152  have an angular or beveled portion  154  to facilitate insertion of the cantilever sections through an aperture in a panel. The tabs  153  remain within the aperture, preventing the cantilever sections  152  from folding outwardly and downwardly, and the notch surface  155  catches on the edge of the panel, preventing the legs  148  from passing into the aperture, as best illustrated in  FIG. 9 . 
     The split ring section  146  of the snap collar  120  is also provided with outwardly oriented spacing lugs  156  that facilitate centering the stud  116 , and thus plate  128 , in the panel aperture. The dimension A across the snap collar  120  at the spacing lugs  156  is determined to closely correspond to the diameter of the aperture in the panel through which the stud  116  is to be disposed. The interior diameter B, as well as depth C, of the split ring section  146  is determined by the size of the recess  136  in the stud  116 . The distance D across the snap collar  120  between cantilever sections  152  is selected to be slightly larger than the distance E across the stud  116  at opposing bosses  138   a ,  138   c  (see  FIG. 9 ). In a particularly preferred embodiment, the dimensions A and E are the same. 
     The split ring section  146  of the snap collar  120  may be provided with a notched section  158  of reduced depth aligned with the notch  140  of stud  116 . The notched section  158  is particularly desired when the device being mounted requires electrical wires or other connections to pass through the panel and provides clearance for such wires or connections. 
     The retaining cap  122  is shown in  FIGS. 13A and 13B . The retaining cap  122  is preferably of stamped and formed metal construction, and comprises a top section  160  having a central aperture  162  which is sized to receive therein the threaded stud  126 . The top section is circular in plan. A plurality of spaced apart fingers  164  are attached to the top section  160  and extend at a generally right angle to the plane of the top section  160  to provide the retaining cap  122  with an overall tubular appearance. In the preferred embodiment shown, four fingers  164  are provided, equally spaced about the circumference of the top section  160 , and separated by slots  165 . 
     As best seen in  FIG. 13B , the fingers  164  have an upper section  166  and a lower section  168 . The upper section  166  is joined to the lower section  168  via intermediate section  170 . The intermediate section  170  is outwardly angled, such that the lower portions  168  of fingers  164  are radially outwardly spaced relative to upper portions  166  and the top section  160 . The angled orientation of intermediate section  170  also forms a beveled shoulder  172  on the inner surface of the fingers  164 . The distance X between fingers  164  disposed on opposite sides of the retaining cap  122  is selected to be slightly larger than the diameter of the body section  130  of stud  116 , whereas the distance Y between the upper surfaces  66  of opposing fingers  164  is smaller than the diameter of the body section  130 . Accordingly, when the retaining cap  122  is positioned over stud  116 , the interior of lower portions  168  of the fingers  164  will be touching, or very nearly touching the exterior surface of the body section  130  of the stud  116  and the beveled shoulder  172  will be resting on the beveled tip  134  of the stud  116 . The width of the slots  165  that separate the fingers  164  is sufficient to permit receipt of the boss members  138   a – 138   c  of the mounting stud  116  therein. 
     Reference is now made to  FIGS. 14A–14D , which illustrate the action of the retaining cap. In these figures, some of the details and components of the invention have been omitted to simplify the illustrations. In use, the device being mounted to the panel  100  is attached to the base assembly  114 . The manner of attachment is not important. The snap collar  120  (not shown in  FIGS. 14A–14D ) is positioned around the stud  116 , as described above. The retaining cap  122  is also positioned around the stud  116  such that the beveled shoulder  172  is resting on the beveled tip  134  and the boss members  138   a ,  138   b , and  138   c  are positioned in respective slots  165  of the retaining cap  122 . The nut  124  is loosely threaded onto the threaded stud  126  and, if desired, a gasket  118  is employed. 
     The entire assembly is then attached to the panel  100  by inserting the stud  116  through the panel aperture  101 . If present, the orientation stud  117  will be disposed through panel aperture  102 . Continued movement toward the panel  100  will cause the resilient legs  152  of the snap collar  120  (not shown) to retract and then expand to their neutral position once they have cleared the interior surface of the panel. The snap collar functions as a temporary holding mechanism while the assembly is being installed. When in the neutral position, the legs  152  contact the interior surface of the panel  100  and prevent the base assembly  114  and the device mounted thereon from moving away from the panel  100 . The retaining legs  152  do not exert any appreciable clamping force against the panel. 
     From the interior of the panel  100 , torque is then applied to the nut  124 . The nut  124  then travels toward the panel  100  along the threaded stud  126 , which in turn forces the retaining cap  122  to move axially toward the base  114  and the panel  100 . As the retaining cap  122  moves toward the base assembly  114  and the panel  100 , the lower portion  168  of the fingers  164  will radially outwardly expand as the beveled shoulder  172  contacts first the beveled tip  134  of the stud  116 , and then the tapered body  130  of stud  116 . The boss members  138   a – 138   c  prevent the retaining cap  122  from rotating relative to the stud  116  as torque is applied to the nut  124 . 
     The radial expansion and axial movement of fingers  164  of the retaining cap  122  toward panel  100  result in the lower portion  168  of the fingers  164  contacting the inner surface of the panel  100 . The snap collar  120  also functions to space the retaining cap  122  a sufficient distance from the panel  100  such that the fingers  164  of the retaining cap cannot enter into the aperture  101 . This process continues until a pre-determined amount of torque has been applied and the panel  100  is firmly clamped between the retaining cap  122  and the base member  114 . In a preferred embodiment, the boss members  138   a  through  138   c  of the stud  116  cooperate with the slots  165  of retaining cap  122  to stop the movement of the retaining cap  122  toward panel  100 , and thus prevent the application of too much torque, which might damage either the panel  100 , the device, or both. 
     The internal electronics of the antenna units shown herein are not critical to the invention, and thus they are not described in any detail. It is, however, a feature of the invention that the base assembly may be configured to accept such electronics or other desired components based on the intended use of the quick-attachment mounting mechanism. For example, referring to  FIG. 9 , the base assembly  114  may be provided with recesses, wells, partitions, or compartments, such as compartments  115   a  and  115   b  to accommodate the components of the device being mounted to the panel using the invention. 
     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.