Abstract:
The present invention is directed to a caster assembly for supporting an object. The assembly includes a caster wheel, a support member rotatably supporting the wheel and first and second side support pieces mounted on the support member. The support member includes a base support surface for engaging and supporting a bottom surface of an object. The first side support piece includes a first support surface adapted to engage and support a first side surface of the object. The second side support piece includes a second support surface adapted to engage and support a second side surface of the object. At least one of the side support pieces is slidably mounted on the support member and is adapted to be moved relative to the other side support piece to permit adjustment of a distance between the between the first and second side support surfaces to accommodate objects of different widths.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention is directed to a caster assembly for supporting an object and, more specifically, to a caster assembly including a caster, a caster housing, a mounting support for supporting an object and a pair of side support pieces mounted on the mounting support for providing lateral support to the object, at least one of the side support pieces being slideable for relative movement with respect to the mounting support such that the caster assembly can support objects having differing width.  
         BACKGROUND ART  
         [0002]    Caster assemblies are used to support an object and facilitate easy movement of an object with respect to flat surfaces such as a floor. Examples of objects using caster assemblies include household appliances such as refrigerators, vacuums, food serving trays and carts, tool carts and cabinets, various items of furniture such chairs, sofas, bed frames and the like. Typically, three or more caster assemblies are used to support an object. The caster assemblies are normally positioned or mounted on the object near an outer peripheral edge of the object to provide a wide, stable base of support. A wide base of support reduces the propensity for the object to tip over during movement of the object across a floor. This is especially important for objects having a relatively high vertical center of gravity.  
           [0003]    Certain objects to be supported on caster assemblies are characterized by a relatively narrow outer peripheral edge. For supporting such an object it is desirable to include support pieces that would bear against opposite side surfaces of the object for greater stability. What is needed is a caster assembly that provides for side support pieces to bear against opposite side surfaces of an object being supported by the caster assembly for greater stability. What is also needed is a caster assembly that provides for adjustable positioning of at least one of the side support pieces to permit a distance between the side pieces to be adjusted so that objects having different edge widths may be accommodated by the caster assembly.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention is directed to a caster assembly for supporting an object.  
           [0005]    In a first preferred embodiment of the caster assembly of the present invention, the caster assembly includes a caster wheel, a support member rotatably supporting the caster wheel and first and second side support pieces mounted on the support member. The support member includes a base support surface for engaging and supporting a bottom surface of the object to be supported. The first side support piece includes a first side support surface for engaging and supporting a first side surface of the object and the second side support piece includes a second side support surface for engaging and supporting a second side surface of the object, the first and second side support surfaces being transverse to the base support surface. At least one of the first and second side support pieces is slidably mounted on the support member and is adapted to be moved relative to the other side support piece to permit adjustment of a distance between the between the first and second side support surfaces to accommodate objects of different widths.  
           [0006]    In a second preferred embodiment of the caster assembly of the present invention, the caster assembly includes a caster wheel, a caster support rotatably supporting the caster wheel, a support housing and first and second side support pieces mounted on the support housing. The support housing is rotatably affixed to the caster support to allow relative rotation between the caster wheel and the first and second side support pieces. The support housing includes a base support surface for engaging and supporting a bottom surface of an object to be supported. The first side support piece includes a first side support surface for engaging and supporting a first side surface of the object and the second side support piece includes a second side support surface for engaging and supporting a second side surface of the object, the first and second side support surfaces being transverse to the base support surface.  
           [0007]    At least one of the first and second side support pieces is slidably mounted on the support housing and is adapted to be moved relative to the other side support piece to permit adjustment of a distance between the between the first and second side support surfaces to accommodate objects of different widths. Advantageously, the support housing includes a locking mechanism which may be engaged to prevent relative rotation between the support housing and the caster support.  
           [0008]    The present invention also is directed to a method of supporting an object having a bottom surface and spaced apart first and second side walls extending upwardly from the bottom surface using a caster assembly that provides a variable distance between first and second side support surfaces of first and second side support pieces of the caster assembly. In an exemplary embodiment, the first step of the method includes: providing a caster assembly that includes a support member rotatably supporting the caster and first and second side support pieces mounted on the support member, the support member includes a base support surface for engaging and supporting a bottom surface of an object to be supported, the first side support piece includes a first side support surface for engaging and supporting a first side surface of the object and the second side support piece includes a second side support surface for engaging and supporting a second side surface of the object, the first and second side support surfaces being transverse to the base support surface and the second side support piece being slidably mounted on the support member for movement relative to the first side support piece.  
           [0009]    The steps of the method further include: sliding the second side support piece such that a distance between the first and second side support surfaces is approximately equal to a distance between the first and second side walls of the object; and moving the caster assembly with respect to the object such that the base support surface engages and supports the bottom surface of the object and the first and second side support surfaces engage and support the first and second side walls of the object.  
           [0010]    These and other objects, advantages and features of the invention will become better understood from a detailed description of an exemplary embodiment of the invention which is described in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of a first preferred embodiment of a caster assembly of the present invention;  
         [0012]    [0012]FIG. 2 is an exploded perspective of the caster assembly of FIG. 1;  
         [0013]    [0013]FIG. 3 is a front elevation view of the caster assembly of FIG. 1;  
         [0014]    [0014]FIG. 4 is a side elevation view of the caster assembly of FIG. 1;  
         [0015]    [0015]FIG. 5 is a section view of the caster assembly of FIG. 1 as seen from a plane indicated by the line  5 - 5  in FIG. 4;  
         [0016]    [0016]FIG. 6 is a perspective view of a support housing of the caster assembly of FIG. 1;  
         [0017]    [0017]FIG. 7 is a second perspective view of the support housing of FIG. 6;  
         [0018]    [0018]FIG. 8 is a top plan view of the support housing of FIG. 6;  
         [0019]    [0019]FIG. 9 is a side elevation view of the support housing of FIG. 6;  
         [0020]    [0020]FIG. 10 is a perspective view of a caster support of the caster assembly of FIG. 1;  
         [0021]    [0021]FIG. 11 is a second perspective view of the caster support of FIG. 10;  
         [0022]    [0022]FIG. 12 is a side elevation view of the caster support of FIG. 10;  
         [0023]    [0023]FIG. 13 is a front elevation view of a second preferred embodiment of a caster assembly of the present invention;  
         [0024]    [0024]FIG. 14 is a front elevation view of the caster assembly of FIG. 13, showing the sliding side supports of the caster assembly in an alternative position;  
         [0025]    [0025]FIG. 15 is an exploded perspective view of the caster assembly of FIG. 13;  
         [0026]    [0026]FIG. 16 is a top plan view of a support housing of the caster assembly of FIG. 13;  
         [0027]    [0027]FIG. 17 is a section view of the support housing of FIG. 16;  
         [0028]    [0028]FIG. 18 is a bottom plan view of the support housing of FIG. 16;  
         [0029]    [0029]FIG. 19 is a perspective view of a sliding side support piece of the caster assembly of FIG. 13;  
         [0030]    [0030]FIG. 20 is a top plan view of a bearing assembly of the caster assembly of FIG. 13;  
         [0031]    [0031]FIG. 21 is a sectional view of the ball bearing assembly of FIG. 20 as seen from a plane indicated by the line  21 - 21  in FIG. 20;  
         [0032]    [0032]FIG. 22 is a top plan view of a caster support of the caster assembly of FIG. 13;  
         [0033]    [0033]FIG. 23 is a perspective view of the caster support of FIG. 22;  
         [0034]    [0034]FIG. 24 is a sectional view of the caster support of FIG. 22 as seen from a plane indicated by the line  24 - 24  in FIG. 22;  
         [0035]    [0035]FIG. 25 is a top plan view of a ball bearing race of the ball bearing assembly of FIG. 20; and  
         [0036]    [0036]FIG. 26 is a top plan view of a ball bearing cage of the ball bearing assembly of FIG. 20;  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]    First Preferred Embodiment of Caster Assembly  
         [0038]    Turning to the drawings, FIGS.  1 - 12  show a first preferred embodiment of a caster assembly of the present invention generally at  10 . The caster assembly  10  includes a support member  12 , and a caster wheel assembly  14  rotatably supported by the support member  12 . The caster assembly  10  further includes first and second side support pieces  20 ,  22  mounted on the support member  12 . The support member  12  includes a lower housing or caster support  30  and an upper or support housing  50  mechanically attached by four #8-32=⅝ inch pan head screws  32 ,  34 ,  36 ,  38  (FIG. 2) which extend between aligned threaded vertical bosses  52 ,  54 ,  56 ,  58  in the support housing  50  and vertical bosses  33 ,  35 ,  37 ,  39  (best seen in FIG. 11) of the caster support  30 .  
         [0039]    Preferably, the caster support and support housing  30 ,  50  and the first and second side support pieces  20 ,  22  are fabricated of an engineering resin material such as urethane rubber or ABS polymer plastic. It should be apparent to others with ordinary skill in the art that alternative suitable materials may be utilized during the practice of this invention.  
         [0040]    As can best be seen in FIG. 2, the caster wheel assembly  14  is affixed to the caster support  30 . The wheel assembly  14  includes a wheel  15  with a central hub  15   a  rotatably mounted on a wheel axle  16 . Preferably, the wheel  15  is fabricated of urethane, the hub  15   a  of high impact polypropylene and the wheel axle  16  of steel. The wheel axle  16  is non-rotatably mounted in a first horizontal throughbore  40  formed in a bottom surface portion  42  of the caster support  30 . The wheel axle  16  includes a square stem portion  16   a  adjacent an enlarged head  16   b  of the axle  16 . The square stem portion  16   a  fits into a square portion  43  (FIG. 12) of the throughbore  40  to prevent rotation of the axle  16  within the throughbore  40 .  
         [0041]    An extending end portion  16   c  of the axle  16  extends into a second horizontal throughbore  44  formed in the bottom surface portion  42  of the caster support  30 . As can best be seen in FIG. 5, a #8-32×{fraction (5/16)} inch pan head screw  17  threads into a threaded opening in the axle end portion  16   c  to secure the wheel  15  on the axle  16 . A washer  18  is disposed between an enlarged head  17   a  of the screw  17  and the hub  15   a  of the wheel  15 . A semicircular recess  46  in the bottom surface portion  42  of the caster support  30  provides clearance for the wheel  15 .  
         [0042]    Plastic covers  60 ,  62  are affixed to the first and second side support pieces  20 ,  22  to prevent dust and dirt from entering openings defined by the honeycomb shaped configuration of the first and second side support pieces  20 ,  22 . An upper surface  64  of the support housing  50  supports the first and second side support pieces  20 ,  22 . The second side support piece  22  is stationary with respect to the support housing  50 . Cylindrical protrusions  23 ,  24 ,  25  extending from a lower surface  26  of the second side piece  22  fit into aligned cylindrical openings  66 ,  68 ,  70  (best seen in FIG. 6) in the upper support surface  64  of the support housing  50  to prevent relative horizontal rotation between the second side support piece  22  and the support housing  50 . A piece of double sided tape  72  (or, alternatively, a layer of adhesive) (FIG. 2) is sandwiched between the lower surface  26  of the second support piece  22  and the upper surface  64  of the support housing  50  to secure the second side support piece  22  to the upper housing.  
         [0043]    Advantageously, the first side support piece  20  is slidable with respect to the support housing  50  thereby permitting a distance D (shown in FIG. 3) between facing side support surfaces  28 ,  29  of the first and second side support pieces  20 ,  22  to be adjusted to accommodate a range of objects having different widths. A projection or key  27  extends from a bottom surface  21  of the first side piece  20 . The key  27  fits into a wider portion (labeled W in FIG. 8) of an opening  80  in the upper surface  64  of the support housing  50 . The key  27  (and, therefore, the first side support piece  20 ) are slidable along a path of travel labeled T in FIGS. 6 and 8. Parallel stepped edges  27   a  of the key  27  (only one of which is seen in FIG. 2) slide in parallel slots  80   a  defining opposing sides of a narrower portion (labeled N in FIG. 8) of the opening  80 .  
         [0044]    The distance D (FIG. 3) between the side support surfaces  28 ,  29  of the first and second side support pieces  20 ,  22  may be varied in an exemplary embodiment of the caster assembly  10  between a minimum distance of about 0.37 inches and a maximum distance of about 0.90 inches. It should be apparent to others with ordinary skill in the art that other travel ranges may be utilized during the practice of this invention.  
         [0045]    Pieces of double sided tape  82 ,  84  are applied to side support surfaces  28 ,  29  to secure the side support surfaces  28 ,  29  to respective sides  97 ,  98  of an object  99  to be supported by the caster assembly  10 . Alternatively, a layer of adhesive may be used. It should also be understood that the first side support piece  20  may be removed if desired to support an object that has a width greater than the maximum distance D provided by the caster assembly  10 . That is, the first side support piece  20  may be removed and the caster assembly  10  used without the first horizontally sliding side piece  20 .  
         [0046]    Typical dimensions for one exemplary embodiment of the caster assembly  10 , as labeled in the drawings are as follows:  
                                       Label   Figure   Dimension                   A   3   1.563 inches       B   4   2.954 inches       C   4   1.170 inches       D   3   0.37 inch minimum-0.90 inch maximum       W   8   1.226 inches       N   8   0.948 inch                  
 
         [0047]    Second Preferred Embodiment of Caster Assembly  
         [0048]    Turning again to the drawings, FIGS.  13 - 24  show a second preferred embodiment of a caster assembly of the present invention generally at  100 .  
         [0049]    As illustrated in FIG. 13, the caster assembly  100  is similar in many respects to the caster assembly  10  disclosed in the first embodiment, but includes an additional feature of relative rotation between a lower housing or caster support  130  and an upper or support housing  150 , that is, rotation with respect to axis A-A as labeled in FIG. 13. The caster assembly  100  includes a support member  112 , and a caster wheel assembly  114  rotatably supported by the support member  112 . The caster assembly  100  further includes first and second side support pieces  120 ,  122  mounted on the support housing  150  of the support member  112 .  
         [0050]    The support housing  150  is rotatably affixed to the caster support  130  and rotates about a ball bearing assembly  300 . The ball bearing assembly is shown in FIGS. 15, 20 and  21 . The ball bearing assembly  300  is disposed within a cavity  151  defined in a lower or bottom side  152  of the support housing  150 .  
         [0051]    The ball bearing assembly  300 , in one exemplary embodiment, is disposed between the caster support  130  and the support housing  150  to provide rotational support between the caster support and the support housing. As is best seen in FIGS. 20 and 21, the ball bearing assembly  300  includes a ball bearing race  308 , a bearing cage  310  and a plurality of ball bearings  312 . In the illustrated embodiment, each ball bearing  312  is equidistantly disposed around an annular path within the ball bearing cage  312 .  
         [0052]    A locking mechanism  319  selectively permits or inhibits relative rotation between the support housing  150  and the caster support  130 . The locking mechanism  319  includes a locking button  320  affixed to the support housing  150 . The lock button  320  extends into an interior region of the support housing  150  through an opening  153  defined in a side wall  154  of the support housing  150  and can slide vertically along a short path of travel. To lock the support housing  150  with respect to the caster support  130 , the locking button  320  is pushed downwardly and fits into a selected one of a select number of arcuate recesses  321  defined in the upper surface  134  of the caster support  130  thus locking the support housing  150  and the caster support  130  together. The openings  321  are defined by eight vertically extending ribs  139 . When the locking button  320  is pushed upwardly and is disengaged from the selected recess  321 , the support housing  150  is free to rotate with respect to caster support  130 .  
         [0053]    Selectively permitting relative rotation between the caster support  130  and the support housing  150  advantageously facilitates a user of the caster assembly  100  positioning the first and second side support pieces  120 ,  122  in a desired orientation to support a fixed, heavy or awkward to move object. To properly orient the first and second side support pieces  120 ,  122 , the user may easily rotate the caster support  130  to a desired position. Subsequently, the use may lock the support housing  150  with respect to the caster support  130 .  
         [0054]    As can best be seen in FIG. 13, 15 and  15 , the caster wheel assembly  114  is affixed to the caster support  130 . The wheel assembly  114  includes a tire  115  with a central hub  115   a  rotatably mounted on a wheel axle rivet  116 . The wheel axle  116  is non-rotatably mounted in a first horizontal throughbore  144  (FIG. 23) formed in a bottom surface portion  133  of the caster support  130 .  
         [0055]    An extending end portion of the axle  116  extends into a second horizontal throughbore  146  formed in the bottom surface portion  133  of the caster support  130 . As can best be seen in FIG. 15, a washer  117  is connected to the distal end of the axle  116  to make a suitable connection to secure the wheel hub  115   a  on the axle  116 . A recess  147  in the bottom surface portion  133  of the caster support  130  provides clearance for the wheel  115 .  
         [0056]    Plastic covers  160 ,  162  are affixed to the first and second side support pieces  120 ,  122  to prevent dust and dirt from entering openings defined by the honeycomb shaped configuration of the first and second side support pieces  120 ,  122 . An upper surface  164  of the support housing  150  supports the first and second side support pieces  120 ,  122 . The second side piece  122  is stationary with respect to the support housing  150 . Three cylindrical protrusions  123 ,  124 , two of which can be seen in FIG. 16, extending from a lower surface  126  of the second side piece  122  fit into aligned cylindrical openings  166 ,  168 ,  170  (best seen in FIG. 16) in the upper surface  164  of the support housing  150  to prevent relative horizontal rotation between the second side support piece  122  and the support housing  150 . A piece of double sided tape  172  (or, alternatively, a layer of adhesive) (FIG. 15) is sandwiched between the lower surface  126  of the second side support piece  122  and the upper surface  164  of the support housing  150  to secure the second side support piece  122  to the support housing  150 .  
         [0057]    As in the first embodiment, the first side support piece  120  is slidable with respect to the support housing  150  thereby permitting a distance between D 2 , shown in FIG. 14, and D 1  shown in FIG. 13, between facing side support surfaces  128 ,  129  of the first and second side support pieces  120 ,  122  to be adjusted to accommodate an object  99  having one of a range of different widths. A projection or key  127  (similar in configuration to the key  27  in the first embodiment of the caster assembly  10  described above) extends from a bottom surface  121  of the first side support piece  120 . The key  127  fits into a wider portion (labeled W in FIG. 16) of an opening  180  in the upper surface  164  of the support housing  150 . The key  127  (and, therefore, the first side support piece  120 ) are slidable along a path of travel labeled T in FIG. 16. Parallel stepped edges  127 a of the key  127  (similar in configuration to the parallel stepped edges  27   a  of the key  27  of the first embodiment) slide in parallel slots (not shown) defining opposing sides of a narrower portion (labeled N in FIG. 16) of the opening  180 .  
         [0058]    The distance D 1 , D 2  between the side support surfaces  128 ,  129  of the first and second side support pieces  120 ,  122  may be varied in an exemplary embodiment of the caster assembly  100  between a minimum distance of about 0.37 inches and a maximum distance of about 0.90 inches. It should be apparent to others with ordinary skill in the art that other travel ranges may be utilized during the practice of this invention.  
         [0059]    Pieces of double sided tape  182 ,  184  are applied to side support surfaces  128 ,  129  to secure the side support surfaces  128 ,  129  to respective sides  97 ,  98  of an object  99  (FIG. 13) to be supported by the caster assembly  100 . Alternatively, a layer of adhesive may be used. It should also be understood that, as was true of the first embodiment, the first side support piece  120  may be removed if desired to support an object that has a width greater than the maximum distance D 2  provided by the caster assembly  100 . That is, the first side support piece  120  may be removed and the caster assembly  100  used without the first horizontally sliding side support piece  120 .  
         [0060]    Typical dimensions for one exemplary embodiment of the caster assembly  100 , as labeled in the drawings are as follows:  
                                       Label   Figure   Dimension                   A   14   2.675 inches       B   14   1.563 inches       C   14   2.770 inches       W   16   1.221 inches       K   14   2.562 inch                  
 
         [0061]    While the present invention has been described with a degree of particularity, it is the intent that the invention include all modifications and alterations from the disclosed embodiments falling within the spirit or scope of the appended claims.