Patent Publication Number: US-2004042873-A1

Title: Bushing

Description:
BACKGROUND  
       [0001] This disclosure is generally directed to a bushing which is designed to be reusable.  
       [0002] Bushings are used to retain fasteners such as bolts or screws within a bore. A degree of flexibility in the materials constituting the bushing help to prevent rattle or shaking and can accommodate variations in the width of a fastener or in the diameter of the bore which occur due to manufacturing tolerances.  
       [0003] One of the problems with currently available bushings is that after a fastener housed in a bushing is inserted into a bore, that same bushing generally cannot be removed and then reinserted. This inability to reuse the bushing is due to shearing that may occur during removal which can cause the bushing to deform.  
       [0004] One example of an industry having a need for a reusable bushing is the automobile industry. In particular, car seats are often attached to a rail which itself is connected the body of the car. The car seat communicates with the rail by means of a fastener being seated in a bore in the rail. It is this fastener that may need to be inserted and removed.  
       [0005] Such seats may need to be removed and reattached for a variety of reasons. A seat may need to be removed after a collision for repair or replacement. Also, car seats today may have features such as heated seats or electric adjustment. To reach components controlling or effecting these features, the seats may need to be removed. There is therefore a need for a reusable bushing that allows the fastener connecting the seat to the rails inside an automobile to be removed and then reinstalled without the need for a new bushing.  
       [0006] Briefly, and in accordance with the foregoing, disclosed is a bushing for the use and reuse in holding a fastener in position within a bore. The bushing has a body portion and an annular perimeter flange. In one embodiment, the body of the bushing has one or more neighboring wall sections separated by slits. The bushing is made from a suitable flexible material which allows the body of the bushing, which has a diameter generally greater than an inside diameter of a bore, to deform to produce an interference fit. A plurality of ribs may be provided along the inside edge of the bushing to provide for increased engagement between the bushing and the fastener.  
       [0007] In a second embodiment, a body portion is composed of a flexible outer wall an inner wall. The outer wall deforms when engaging the inner walls of a work-piece to produce an interference fit. The diameter of the inner wall is slightly smaller than the outside diameter of the fastener which provides a further tight fit of the bushing around the fastener.  
       [0008] Additional features will become apparent to those skilled in the art upon consideration of the following detailed description of drawings exemplifying the best mode as presently perceived. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] The detailed description particularly refers to the accompanying figures in which:  
     [0010]FIG. 1 is a perspective view of a bushing;  
     [0011]FIG. 2 is a side elevational view thereof;  
     [0012]FIG. 3 is a cross-sectional view thereof taken along line  3 - 3  in FIG. 1;  
     [0013]FIG. 4 is a top plan view thereof;  
     [0014]FIG. 5 is a cross-sectional view of a fastener seated in the bushing;  
     [0015]FIG. 6 is a cross-sectional view of the fastener seated in the bushing, and the fastener and bushing engaging a bore in a work piece;  
     [0016]FIG. 7 is a perspective view of another embodiment of a bushing; and  
     [0017]FIG. 8 is a cross-sectional view of thereof taken along line  8 - 8  in FIG. 7; 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0018] While the present disclosure may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, embodiments with the understanding that the present description is to be considered an example of the principles of the disclosure and is not intended to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings.  
     [0019] With reference to the figures, FIG. 1 shows a perspective view of a bushing  5 . The bushing  5  has a wall  6  defining a generally tubular body  10 . One or more slits  14  are provided in the wall  6  to divide the body  10  into neighboring wall body portions  8 . The slits  14  divide the wall  6  starting from a first end  13  in a direction toward a second end  15 , and continuing a portion of the distance between the first end  13  and the second end  15 . An annular perimeter flange  12  extends generally perpendicularly from the second end  15  of the wall  6  of the body  10 .  
     [0020] The bushing  5  is formed of a material that provides a degree of flexibility which may include but is not limited to metal or plastic. This flexibility is desired to allow a central portion  17  of the wall body portions  8  of the bushing  5  to flex inwardly when the bushing  5  is inserted into a bore  40  (see FIG. 6). The bushing  5  may also not include the slits  14 , but the slits  14  are shown because they have been found to provide some degree of added flexibility. FIG. 2, shows a side elevational view of the bushing  5 .  
     [0021] The slits  14  can be formed in the wall  6  either by process of cutting the wall  6  after the bushing  5  is formed or by forming the slits  14  in the wall during a forming process during which the bushing  5  is formed. In this regard, the bushing could be formed by molding plastic or metal to achieve the desired shape. As noted, the as formed bushing  5  could be formed with slits  14  or could be further processed by cutting or other operation to form the slits  14 .  
     [0022] As shown in FIG. 3 and FIG. 4, an interior surface  18  of the wall body portion  8  of the bushing  5  may also include one or more protrusions or ribs  20  generally evenly spaced around the interior surface  18 . The ribs  20  are generally evenly spaced around the interior surface in order to provide a centering function for effect on the bushing  5 . Additionally, the ribs  20  are generally positioned on the interior surface  18  in the area proximate to the junction of the second end  15  of the wall  6  and the flange  12 . This is generally an area which does not flex, as does the generally curved central portion  17  of the wall  6 . These ribs  20  are also made of a flexible material which allows them to deform when a fastener is inserted into the interior  18  of the bushing  5 . The ribs  20  are thus able to provide a degree of engagement which holds the fastener in place.  
     [0023]FIG. 5 shows the bushing  5  with a fastener  22  seated therein. As discussed above, the fastener  22  may be for example, a bolt, screw, rivet or other structure protruding from a car seat (not shown) which is insertable in a rail (not shown) attached the body of the car. As shown in FIGS. 5 and 6 a fastener  22 , in this embodiment shown as a double-ended stud, is positioned in the bushing  5  with the body  10  abutting a shoulder or dowl portion  30 . The dowl portion  30  might also be referred to as a stud shoulder. As shown in FIGS. 5 and 6, the fastener  22  has a first portion  23  and a second portion  25 . The first portion  23  could be screwed into a seat and the second portion  25  could be bolted or screwed onto a rail. This arrangement may be reversed if the bushing  5  is oriented such that the flange  12  abuts the underside of a rail.  
     [0024]FIG. 6 shows the bushing  5  with the fastener  22  seated therein proximate to a work piece  32 . A bore  40  is formed in the work piece  32  which as an inside diameter  38  defined by the distance between opposite sides of an interior surface  36 . The tubular body  10  is shown in a deformed state. The deformed state of the tubular body  10  results from the inward flexion of the wall  6 . The inward flexion of the wall  6  occurs as a result of an outside diameter  26  of the body  10  as shown in FIG. 5 being slightly larger than the inside diameter  38  of the bore  40  as shown in FIG. 6. As noted above, the body portion  10  of the bushing  5  being formed of a material which can be flexed to some degree. It should be noted that while the body  10  may generally have somewhat rigid characteristics, the material has been chosen to provide a degree of flexibility when the body  10  is inserted into the bore. For example, one material which might be used in the formation of the bushing  5  could be nylon.  
     [0025] Generally, as shown in FIGS.  1 - 6 , the differential between the outside diameter  26  defined by outer surfaces  24  of the body  10  of the bushing  5  and the inside diameter  38  of the bore  40  is equal to or less than the sum of the dimensions defined by gaps  41 . Gaps  41  are defined between opposite sides of the bushing  5  and fastener  22 . For example, as shown in FIG. 5, the gaps  41  are defined between an outside surface  43  of the stud shoulder  30  and the inside surface  28  of the body  10  generally at the central portion  17  of the wall  6 . The gaps  41  generally, can be no larger than the differential unless the material used to form the body  10  is, in itself, provides a degree of compressibility. In this deformed state, the wall  6  of the body  10  creates an outwardly directed force which cause an exterior surface  24  to impinge on the corresponding exterior surface  36  of the work-piece  32 . This force helps provide an interference fit to retain the bushing  5  and the fastener  22  seated therein inside the bore  40 . When so engaged, the bushing  5  acts to hold the fastener  22  in a captive position which reduces undesirable rattle or vibration and prevents the fastener  22  from sliding out.  
     [0026] The bushing  5  may also be constructed to be retained in the bore  40  when the fastener  22  is removed. Such a design may not include the ribs  20  along the interior  18  of the bushing  5 . The work piece  32  may be fabricated with the bore  40  slightly larger or slightly smaller, with such variation within a specified tolerance. Similarly, fasteners  22  may be manufactured with slightly different diameters, still within a specified tolerance (e.g. plus or minus 0.005 centimeters). The bushing  5  helps to provide an interference fit by flexing to accommodate the variations in the dimensions of fasteners  22  and bores  40 .  
     [0027]FIG. 7 shows another embodiment of the bushing  5   a  that has a generally curved outer wall  44  and a generally tubular, inner wall  46 . As shown in FIG. 8, the inner wall  46  and outer wall  44  are joined in a merged portion  50  proximate to the flange  12 . An annular slot  51  is defined between an interior surface  52  of the outer wall  44  and an outer surface  53  of the inner wall  46 . The outer wall  44  provides a similar flexible deforming function as described herein above with regard to the wall  6  of the body  10  of the first embodiment shown and described above. The outer wall  44  is further defined by a first end  60  and a second end  61 , and a central or displaced portion  63 . The central or displaced portion  63  may tend toward or away from a central axis  55 . The inner wall  46  defines a bore or passage  54  and a diameter  48  measured between the interior surfaces  47  of the inner wall  46 . A dimension  64  between the central axis  55  and the first end  60  and a dimension  66  between the central axis  55  and the second end  61  is generally equal. The dimension  65  between the central axis  55  and central or displaced portion  63  may be greater than the dimensions  64 ,  66  as the outer wall  46  flexes to accommodate the fastener  22 . The inner wall  46  is generally spaced equally from the central axis  55 . The interior diameter  48  of the inner wall  46  is slightly smaller than or generally equal to diameter  70  of the fastener  22  (see FIGS. 5 and 6 for the fastener  22 ). This dimensional relationship facilitates an interference or snug fit of a fastener  22  in the bore  54  of the bushing  5   a.  The interference generally secures the bushing  5   a  on the fastener  22 , generally in the shoulder area  30  to retain it in a desired position.  
     [0028] While preferred embodiments of the disclosure are shown and described, it is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the spirit and scope of the disclosure as recited in the following claims.