Abstract:
A particular method includes disposing a first structure and a second structure adjacent to each other. A fastener is extended from the second structure through a hole and a counterbore defined in the first structure. A first bushing is placed over the fastener by receiving the fastener through an elongated opening defined in the first bushing. When the fastener is not centered relative to the hole, the first bushing is rotated around the fastener and a position of the fastener is adjusted in the elongated opening until the first bushing is received into the counterbore defined in the first structure. The fastener is received through an opening defined in a second bushing. The first structure and the first and second bushings are secured onto the fastener.

Description:
CLAIM OF PRIORITY 
       [0001]    This divisional application claims priority from U.S. patent application Ser. No. 11/480,097, filed on Jun. 29, 2006, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Modifications or alterations to a vehicle or a facility may be made from time to time during the service life of a vehicle or facility. For example, additional equipment or systems may be added, either permanently or on a temporary basis. 
         [0003]    Equipment or systems may be attached directly to attach points of the structure of the vehicle or facility. Alternately, a mounting structure, such as for example a false floor or the like, may be attached to the attach points, and the equipment or systems may be mounted on the mounting structure as desired. This latter approach permits the installation of equipment or systems without modifications to the structure of the vehicle or facility. Regardless of whether equipment, systems, or mounting structures (collectively, “mounted structure”) are attached to the attach points, the mounted structure is attached to the attach point via a fastener. 
         [0004]    Mounting holes for receiving the attach point fasteners are planned and defined in the mounted structure based upon documented location of the attach point fasteners. In some applications the mounting hole may be counter-bored such that the attach point fastener will not extend past an upper surface of the mounted structure. The mounted structure is placed on the structure of the vehicle or facility such that the attach point fasteners are received in the mounting holes. 
         [0005]    However, a variability may exist between documented location of an attach point fastener and actual location of the attach point fasteners. This variability may result from, without limitation, inaccurate documentation, assembly processes with large tolerances for inaccurate location, heavy use, damage, field repairs, or any combination thereof. In some instances, the variability may be on the order of around an inch or so. However, there is no limit to possible variability. 
         [0006]    In the event of a large variability, a mounting hole that was defined based on a documented location of a fastener may not align properly with the actual location of the fastener. In the case of a counter-bored mounting hole, attachment may be precluded even if the attach point fastener fits within the counter-bored hole. This is because bushings or washers received within the counter-bored hole may not align with the fastener. 
         [0007]    In such cases, the mounting hole may be re-drilled. Alternately, in some cases, a new mounted structure may have to be fabricated. Such rework introduces delays and cost increases into a modification or alteration. 
         [0008]    The foregoing examples of related art and limitations associated therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
       SUMMARY 
       [0009]    The following embodiments and aspects thereof are described and illustrated in conjunction with systems and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the problems described above in the Background have been reduced or eliminated, while other embodiments are directed to other improvements. 
         [0010]    In an exemplary, non-limiting bushing assembly, a first bushing defines a first opening therethrough. The first opening has a first dimension along a first axis that is sized to receive a fastener therethrough. The first opening has a second dimension along a second axis, and the second dimension is larger than the first dimension. A second bushing defines a second opening therethrough that is sized to receive a fastener therein. Means are provided for engaging the first and second bushings. 
         [0011]    According to an aspect, the engaging means may be provided by serrations defined on a surface of the first bushing and serrations defined on a surface of the second bushing. Alternately, the engaging means may be provided by, without limitation: an abrasive surface treatment defined on a surface of the first bushing and defined on a surface of the second bushing; an adhesive affixed to a surface of at least one of the first and second bushings; hook and loop fasteners affixed to the first and second bushings; or the like, as desired for a particular application. 
         [0012]    According to another aspect, the first opening may be a slot. Further, the dimension along the second axis of the slot may be at least one-half an amount of variability of an actual location of a fastener from a documented location of the fastener. 
         [0013]    In another exemplary, non-limiting bushing assembly, a first bushing defines a first slot therethrough that has a first dimension along a first axis that is sized to receive a fastener therethrough. The first bushing has a second dimension along a second axis that is larger than the dimension along the first axis. The first bushing defines a second slot therethrough that has a third dimension along the first axis that is bigger than the first dimension and that has a fourth dimension along the second axis that is larger than the second dimension. A second bushing defines a second opening therethrough that is sized to receive a fastener therein. Means are provided for engaging the first and second bushings. 
         [0014]    Exemplary bushing assemblies may be used in attaching two structures to each other. In an exemplary method of attaching two structures to each other, a first structure and a second structure are disposed against each other such that a fastener that extends from the second structure is received in a counter-bored hole defined in the first structure. An actual location of the fastener may have a variability from a documented location of the fastener, and the counter-bored hole is defined to receive the fastener in the documented location of the fastener. A first bushing is placed into the counter-bored hole, and the first bushing defines a first opening therethrough that has a first dimension along a first axis that is sized to receive the fastener therethrough and that has a second dimension along a second axis that is larger than the dimension along the first axis. The first bushing is rotated until the first bushing receives the fastener therein. A second bushing is placed onto the first bushing, and the second bushing defines a second opening therethrough that is sized to receive the fastener therein. The first and second bushings engage with each other, and the first structure and the first and second bushings are secured onto the fastener. 
         [0015]    In addition to the exemplary embodiments and aspects described above, further embodiments and aspects will become apparent by reference to the drawings and by study of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
           [0017]      FIG. 1  is an exploded perspective view of a buildup of two structures and an exemplary bushing assembly; 
           [0018]      FIG. 2A  is a perspective view of an exemplary compensator bushing; 
           [0019]      FIGS. 2B-2F  are plan views of the bushing of  FIG. 2A ; 
           [0020]      FIG. 3A  is a perspective view of an exemplary lock bushing; 
           [0021]      FIGS. 3B-3F  are plan views of the bushing of  FIG. 3A ; 
           [0022]      FIG. 4A  is a partial cutaway perspective view of the compensator bushing of  FIG. 2A  and the lock bushing of  FIG. 3A  engaged with each other; 
           [0023]      FIG. 4B  is a perspective view of the compensator bushing of  FIG. 2A  and the lock bushing of  FIG. 3A  engaged with each other; 
           [0024]      FIGS. 4C-4H  are top plan views illustrating exemplary engagement of an exemplary compensator bushing and an exemplary lock bushing; 
           [0025]      FIGS. 5A-5C  are top plan views illustrating placement of an exemplary compensator bushing in a counter-bored hole; 
           [0026]      FIG. 6  is a perspective view of two structures attached to each other using an exemplary bushing assembly; 
           [0027]      FIG. 7  is a partial cutaway perspective view of another exemplary bushing assembly held together with a retainer clip; 
           [0028]      FIG. 8A  is a perspective view of the exemplary compensator bushing of  FIG. 7 ; 
           [0029]      FIGS. 8B-8F  are plan views of the bushing of  FIG. 8A ; 
           [0030]      FIG. 9A  is a perspective view of the exemplary lock bushing of  FIG. 7 ; and 
           [0031]      FIGS. 9B-9F  are plan views of the bushing of  FIG. 9A   
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Given by way of overview and referring to  FIG. 1 , an exemplary bushing assembly  10  may be used in attaching two structures  12  and  14  to each other. Given by way of non-limiting example, the structures  12  and  14  are disposed against each other such that a fastener  16  that extends from the structure  14  is received in a counter-bored hole  18  defined in the structure  12 . An actual location of the fastener  16  may have a variability, v, from a documented location (not shown for clarity) of the fastener  16 , and the hole  18  is defined to receive the fastener  16  in the documented location of the fastener  16 . A compensator bushing  20  is placed in the hole  18 , and the compensator bushing  20  defines an opening  22  therethrough that has a dimension  1   1  along an axis a 1 , that is sized to receive the fastener  16  therethrough and that has a dimension  1   2  along an axis a 2  that is larger than the dimension  1   1 . The compensator bushing  22  is rotated until the compensator bushing  20  is received in the counter-bored hole  18 . A lock bushing  24  is placed onto the compensator bushing  20 , and the lock bushing  24  defines an opening  26  therethrough that is sized to receive the fastener  16  therein. The bushings  20  and  24  engage with each other, and the structure  12  and the bushings  20  and  24  are secured onto the fastener  16 , thereby securing the structure  12  to the structure  14 . Details will now be set forth below. 
         [0033]    Referring additionally to  FIGS. 2A-2F , the compensator bushing  20  defines surfaces  28  and  30  and a side  32 . The compensator bushing  20  has an outer diameter that is equalized with a diameter of the counter-bore of the counter-bored hole  18 . The opening  22  extends completely through the compensator bushing  20  from the surface  28  to the surface  30 . In an exemplary embodiment, the opening  22  is a slot. The compensator bushing  20  may have any shape as desired for a particular application. While the compensator bushing  20  is shown herein as having a circular (that is, round) shape, the compensator bushing  20  may have any shape, such as without limitation oval, or square, or rectangular, or the like, as desired for a particular application. 
         [0034]    The dimension  1   1  is sized to receive therein the fastener  16 . The dimension  1   2  is bigger than the dimension  1   1  and is sized to accommodate the variability v of the actual location of the fastener  16  from the documented location of the fastener  16 . Because the compensator bushing  20  can be rotated 360 degrees in the counter-bored hole  18 , the opening  22  can accommodate the variability v that is up to two times the dimension  1   2 . That is, the dimension  1   2  can be as little as one-half the length of the variability v. Thus, the dimension  1   2  is at least one-half the length of the variability v. The full variability v can be accommodated by rotating the compensator bushing  20  in the counter-bored hole  18  until the opening  22  is aligned to receive the fastener  16  therein. Given by way of non-limiting example, when the variability v is around ½ inch, the dimension  1   2  can be at least ¼ inch. 
         [0035]    The compensator bushing  20  may have any thickness t 1 , as desired for a particular application. As a result, the thickness t 1  may be sufficiently thin that the compensator bushing  20  may be considered and referred to as washer. Thus, the term “bushing” as used herein is intended to include “washer” within its meaning. Further, the compensator bushing  20  may be made from any material whatsoever, such as without limitation plastic or metals such as stainless steel or titanium, as desired for a particular application. Factors that may be taken into consideration for selection of materials may include: whether the compensator bushing  20  will be used to transfer load; electro-corrosive compatibility with materials used for the fastener  16  and the structures  12  and  14  (such as avoiding use of dissimilar metals); environmental factors; or the like. 
         [0036]    Referring additionally to  FIGS. 3A-3F , the lock bushing  24  defines surfaces  34  and  36  and a side  38 . The lock bushing  24  has an outer diameter that is smaller than a diameter of the counter-bore of the counter-bored hole  18 . The opening  26  extends completely through the lock bushing  24  from the surface  34  to the surface  36 . The opening  26  has a diameter that is sized to receive the fastener  16  therein. The lock bushing  24  may have any shape as desired for a particular application. While the lock bushing  24  is shown herein as having a circular (that is, round) shape, the lock bushing  24  may have any shape, such as without limitation oval, or square, or rectangular, or the like, as desired for a particular application. 
         [0037]    The lock bushing  24  may have any thickness t 2  as desired for a particular application. As a result, the thickness t 2  may be sufficiently thin that the lock bushing  24  may be considered and referred to as washer. Thus, the term “bushing” as used herein is intended to include “washer” within its meaning. Like the compensator bushing  20 , the lock bushing  24  may be made from any material whatsoever, such as without limitation plastic or metals such as stainless steel or titanium, as desired for a particular application. Factors that may be taken into consideration for selection of materials for the lock bushing  24  are the same as those set forth above for the compensator bushing  20 . 
         [0038]    The compensator bushing  20  and the lock bushing  24  each include features that cooperate together to provide means for engaging the compensator bushing  20  and the lock bushing  24 . In an exemplary embodiment, serrations  40  are defined on the surface  28  of the compensator bushing  20  and serrations  42  are defined on the surface  34  of the lock bushing  24 . The serrations  40  are parallel and the serrations  42  are parallel. In an exemplary embodiment, the serrations  40  and  42  extend across the entire surfaces  28  and  34 , respectively. 
         [0039]    The serrations  40  and  42  are made as small as desired for a particular application. Use of small serrations allows for finer control of variability of tolerances and a tighter tolerance with the shaft of the fastener  16 . In an exemplary, non-limiting embodiment, the serrations  40  and  42  are made according to industry machining standards. 
         [0040]    As best seen in  FIGS. 2A and 2B , in an exemplary embodiment the serrations  40  are aligned on the surface  28  of the compensator bushing  20  such that their axes form a non-zero angle with the axis a 2  (that is, the serrations  40  are not parallel with the axis a 2 ). The non-zero angle suitably is no more than ninety degrees. The amount of load that can be transferred is maximized when the non-zero angle is ninety degrees. The amount of load that can be transferred is reduced as the non-zero angle approaches zero. This reduction results because, after the lock bushing  24  is placed onto the compensator bushing  20 , the lock bushing  24  could slide on the serrations  40  and  42  along the axis a 2 . 
         [0041]    Referring additionally to  FIGS. 4A and 4B , after the compensator bushing  20  is placed into the counter-bored hole  18  (not shown in  FIGS. 4A and 4B ), the surface  34  of the lock bushing  24  is placed against the surface  28  of the compensator bushing  20  such that “teeth” of the serrations  40  and  42  are received within (that is, engaged with) “valleys” of the serrations  42  and  40 , respectively. 
         [0042]    The means for engaging may be implemented in several ways in other exemplary embodiments, as desired. For example, referring now to  FIG. 4C , in another exemplary embodiment the surface  34  of a lock bushing  24 C and the surface  28  of a compensator bushing  20 C may be treated with a surface treatment  54  to provide a non-skid type surface with an increased coefficient of static friction. The surface treatment  54  may be effected by any suitable, abrasive mechanical processing or by a suitable chemical processing, such as an acid bath or the like. After the compensator bushing  20 C is placed into the counter-bored hole  18  (not shown in  FIG. 4C ), the surface  34  of the lock bushing  24 C is placed against the surface  28  of the compensator bushing  20 C such that the increased coefficient of static friction of the surface treatment  54  engages the lock bushing  24 C and the compensator bushing  20 C. This engagement is similar to a knurled or cross-hatched washer that is used to prevent a nut from loosening after installation. 
         [0043]    Referring now to  FIGS. 4D ,  4 E, and  4 F, in another exemplary embodiment an adhesive  56  may be affixed only to the surface  34  of a lock bushing  24 D ( FIG. 4D ) or only to the surface  28  of a compensator bushing  20 D ( FIG. 4E ) or to the surface  34  of the lock bushing  24 D and to the surface  28  of the compensator bushing  20 D ( FIG. 4F ), as desired. After the compensator bushing  20 D is placed into the counter-bored hole  18  (not shown in  FIGS. 4D ,  4 E, and  4 F), the surface  34  of the lock bushing  24 D is placed against the surface  28  of the compensator bushing  20 D. The adhesive  56  is allowed to cure, thereby engaging the lock bushing  24 D and the compensator bushing  20 D. 
         [0044]    Referring now to  FIGS. 4G and 4H , in another exemplary embodiment hook and loop fasteners may be used to engage a lock bushing  24 E and a compensator bushing  20 E in applications subject to light loading. Hooks  58  may be affixed to the surface  34  of the lock bushing  24 E and loops  60  may be affixed to the surface  28  of the compensator bushing  20 E ( FIG. 4G ). Alternately, the loops  60  may be affixed to the surface  34  of the lock bushing  24 E and the hooks  58  may be affixed to the surface  28  of the compensator bushing  20 E ( FIG. 4H ). After the compensator bushing  20 E is placed into the counter-bored hole  18  (not shown in  FIGS. 4G and 4H ), the surface  34  of the lock bushing  24 E is placed against the surface  28  of the compensator bushing  20 E. The hooks  58  engage the loops  60 , thereby engaging the lock bushing  24 E and the compensator bushing  20 E. 
         [0045]    Referring now to  FIGS. 5A ,  5 B, and  5 C, the structure  12  is placed onto the fastener  16  that may or may not be mislocated. The compensator bushing  20  is rotated as desired (if at all) to compensate for any mislocation of the fastener. In  FIG. 5A , the fastener  16  is centered. The compensator bushing  20  is placed onto the fastener  16  and fits into the counter-bored hole  18  without being rotated. The lock bushing  24  is placed onto and engages the compensator bushing  24 . 
         [0046]    In  FIG. 5B , the fastener  16  is mislocated by an intermediate amount of variability. The compensator bushing  20  is placed onto the fastener  16  and is rotated until the compensator bushing  20  fits into the counter-bored hole  18 . The lock bushing  24  is placed onto and engages the compensator bushing  24 . 
         [0047]    In  FIG. 5C , the fastener  16  is mislocated by an amount of variability that is greater than that shown in  FIG. 5B . The compensator bushing  20  is placed onto the fastener  16  and is rotated (more than the amount of rotation shown in  FIG. 5B ) until the compensator bushing  20  fits into the counter-bored hole  18 . The lock bushing  24  is placed onto and engages the compensator bushing  24 . 
         [0048]    Referring now to  FIGS. 1 AND 6 , after the compensator bushing  20  is placed about the fastener  16  in the counter-bored hole  18  and the lock bushing  24  engages the compensator bushing  20 , a washer  62  is placed onto the lock bushing  24 . A nut  64  is placed onto threads of the fastener  16  and is tightened, thereby securing the structure  12  (and the compensator bushing  20  and the lock bushing  24 ) onto the fastener  16 . 
         [0049]    Referring now to  FIGS. 7 ,  8 A, and  9 A, in some applications such as modifications or alterations or retrofits or repairs made in the field, it may be desirable to provide a bushing assembly as a one-piece unit. To that end, and given by way overview of another non-limiting example, in an exemplary bushing assembly  110  a compensator bushing  120  defines a slot  122  therethrough that has the dimension  1   1  along the axis a 1 , that is sized to receive the fastener  16  (not shown) therethrough. The compensator bushing  120  has a dimension  1   2  along an axis a 2  that is larger than the dimension  1   1 . The compensator bushing  120  defines a slot  123  therethrough that has a dimension  1   3  along the axis a 1 , that is bigger than the dimension  1   1  and that has a dimension  1   4  along the axis a 2  that is larger than the dimension  1   2 . A lock bushing  124  defines an opening  126  therethrough that is sized to receive the fastener  16  (not shown) therein. Means are provided for engaging the bushings  120  and  124 . Details will now be set forth below. 
         [0050]    Referring additionally to  FIGS. 8B-8F , the compensator bushing  120  is similar to the compensator bushing  20  ( FIGS. 2A-2F ) except that the compensator bushing  120  additionally defines the slot  123 . The slot  123  accommodates a retainer clip  102  and washer  104 . Moreover, a side  132  of the compensator bushing  120  optionally may be chamfered over a thickness t 3 , if desired, for radius relief. If provided, the chamfer may have any degree measurement as desired. The compensator bushing  120  includes the features that contribute to the means for engaging the lock bushing that are described above for the compensator bushing  20 . 
         [0051]    Referring now to  FIGS. 9A-9F , the lock bushing  124  is similar to the lock bushing  24  ( FIGS. 3A-3F ) except an opening  126  optionally may be chamfered toward a surface  136 , if desired. If provided, the chamfer may have any degree measurement as desired. The chamfer may accommodate receiving a one-piece nut  106  ( FIG. 7 ) thereagainst without a washer. 
         [0052]    Because the bushing assembly  110  is a one-piece assembly, the compensator bushing  120  is rotated until it fits into the counter-bored hole  18  (not shown) and the nut  106  is rotated to secure the structure  12  (not shown) onto the fastener  16  (not shown). 
         [0053]    While a number of exemplary embodiments and aspects have been illustrated and discussed above, those of skill in the art will recognize certain modifications, permutations, additions, and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, and sub-combinations as are within their scope.