Patent Document

BACKGROUND OF THE INVENTION 
     The present invention relates generally to pallets and more particularly to a snap-together pallet. 
     Pallets are often used to store and transport goods. Pallets maintain the goods at a distance above the floor such that they can readily be lifted and moved by a forklift. Plastic pallets are lighter and more durable than wooden pallets. 
     Many plastic pallets have separately molded upper and lower decks separated by columns that define the fork-receiving areas. The upper and lower decks and the columns are molded separately and subsequently connected via adhesive, hot plate welding, heat stakes, or similar methods. These connection processes can be time-consuming and raise the assembly cost. 
     Pallets with some snap-together assembly have been developed. Two such pallets, developed by the assignee of the present application, are disclosed in U.S. Pat. Nos. 6,006,677 and 6,622,641. Those pallets include a top deck having a plurality of ribs extending downward. Snap-tabs connect a plurality of columns to the top deck. Ribs in the top deck provide strength and rigidity to the top deck. 
     SUMMARY OF THE INVENTION 
     A pallet according to the present invention provides increased strength to a top deck that is snap-fit to columns of a base. The pallet generally includes a top deck, a mid-top member and a base. The top deck has a plurality of ribs extending downwardly and a plurality of column-receiving recesses formed on the underside thereof. 
     The base includes a plurality of columns projecting substantially vertically and received within the recesses of the top deck. The columns define fork-receiving regions therebetween. Snap-tabs secure the columns to the deck. 
     A generally planar mid-top member has a plurality of openings corresponding to the plurality of columns. The mid-top member is sandwiched between the ribs of the top deck and shoulders formed on the outer periphery of the columns, which partially extend into the openings of the mid-top member. 
     In one embodiment, the mid-top member is secured directly to the plurality of ribs on the deck. In another embodiment, the mid-top member is first snap-fit to the top deck. The assembled mid-top member and top deck are then assembled to the base via snap-fit connections. 
     Pallets according to the present invention provide top decks that are stronger and more rigid. The pallets are also easier to assemble than previous pallets. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages of the present invention can be understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
         FIG. 1  is a perspective view of a pallet according to a first embodiment of the present invention. 
         FIG. 2  is an exploded view of the pallet of  FIG. 1 . 
         FIG. 3  is a bottom perspective view of the top deck of the pallet of  FIG. 1 . 
         FIG. 4  is a bottom perspective view of the top deck of  FIG. 3  connected to the mid-top member. 
         FIG. 5  is a perspective view of the base of the pallet of  FIG. 1 . 
         FIG. 6  shows the alignment of the mid-top member on the base of  FIG. 5 . 
         FIG. 7   a  is an exploded sectional view taken along lines  7 - 7  of  FIG. 1 . 
         FIG. 7   b  is an assembled view similar to  FIG. 7   a.    
         FIG. 8  is an enlarged view of the area around the center column of  FIG. 7   b.    
         FIG. 9   a  is an enlarged view of the Area A of  FIG. 7   b  prior to attachment of the top deck to the mid-top member. 
         FIG. 9   b  is the area of  FIG. 9   a  after attachment of the top deck to the mid-top member. 
         FIG. 10  is a perspective view of a pallet according to a second embodiment of the present invention. 
         FIG. 11  is an exploded view of the pallet of  FIG. 10 . 
         FIG. 12  is a bottom perspective view of the top deck connected to the mid-top member and exploded from the base of  FIG. 10 . 
         FIG. 13  is an enlarged perspective bottom view of a portion of the top deck of  FIG. 10 . 
         FIG. 14  is a bottom perspective view of the mid-top member of  FIG. 10 . 
         FIG. 15  is a sectional view through the mid-top member and top deck of  FIG. 10 . 
         FIG. 16  is bottom perspective view of a diagonal section through the assembled pallet of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A pallet  10  according to a first embodiment of the present invention includes a top deck  12  having a generally planar upper member  14  for supporting goods at a distance above the floor. The top deck  12  is secured to a base  18  having a plurality of generally vertical columns  20  connected by runners  22  and defining fork-receiving areas. 
       FIG. 2  is an exploded view of the pallet  10 . A mid-top member  30  is sandwiched between the top deck  12  and the base  18 . The mid-top member  30  is a generally planar, rigid, synthetic resin plate having a plurality of openings  34 , including a center opening  34   a , side openings  34   b  and corner openings  34   c . The openings  34  correspond to and are aligned with the columns  20  of the base  18 . The columns  20  each include an upper portion  40  having a reduced outer dimension, thereby forming a shoulder  42  adjacent the upper portion  40 . 
       FIG. 3  is a bottom perspective view of the top deck  12 . The underside of the top deck  12  includes a plurality of intersecting, transverse ribs  46  extending downward. At each intersection of the ribs  46 , the ribs  46  are slightly taller to form downward projections  48 . The top deck  12  includes a plurality of column-receiving recesses  50 . A plurality of interior ribs  52  and snap-tabs  54  extend downward within each recess  50 . Short channel ribs  56  between the ribs  46  and the interior ribs  52  of each recess  50  define a channel  58 . A lip  60  extending around the periphery of the top deck  12  is taller when adjacent each recess  50  (other than the center recess  50 ) and is spaced from the interior ribs  52  and snap-tabs  54 . 
       FIG. 4  is a bottom perspective view of the mid-top member  30  connected to the top deck  12 . As shown, the openings  34  in the mid-top member  30  are aligned with the recesses  50  in the top deck  12 , such that the recesses  50 , channel  58 , short channel ribs  56 , interior ribs  52  and snap-tabs  54  are accessible. 
       FIG. 5  is a perspective view of the base  18 . Each column  20  includes the upper portion  40  of reduced outer dimension to form the shoulder  42 . A flange  64  extends radially inward from the top of the upper portion  40  into a hollow of the column  20 . 
       FIG. 6  is a perspective view of the base  18  with the mid-top member  30  aligned on the base  18 . The columns  20  are received in the openings  34  of the mid-top member  30 . The mid-top member  30  rests on the shoulders  42  of the columns  20  of the base  18 , such that the upper portions  40  protrude through the openings  34  in the mid-top member  30 . 
       FIGS. 7   a  and  7   b  are sectional exploded and assembled views, respectively, of the pallet taken along line  7 - 7  of  FIG. 1 . The upper portions  40  of the columns  20  are received in the openings  34  in the mid-top member  30 . The top deck  12  is secured to the base  18  via the connection of the snap-tabs  54  to the columns  20 . The mid-top member  30 , together with the ribs  46  and the planar upper member  14 , forms box beam sections in the top deck  12 . The box beam sections provide increased strength and rigidity to the top deck  12 . The lip  60  rests on the shoulder  42  adjacent each peripheral column  20 . 
     An enlarged view of the area around the center column  20  is shown in  FIG. 8 . Connection to the other columns  54  is similar. When assembled, the mid-top member  30  rests on the shoulders  42  of the columns  20 , such that the upper portion  40  is received within the opening  34  of the mid-top member  30 . The ribs  46  of the top deck  12  abut the upper surface of the mid-top member  30 . The top deck  12  is secured to the base via the snap-tabs  54  in the columns  20 . The columns  20  are inserted into the channels  58  of the recesses  50  on the top deck  12  as the snap-tabs  54  and interior ribs  52  are inserted into the columns  20 . The sloped portion  70  of each snap-tab  54  initially abuts the flange  64  of the column  20 . Upon further insertion, the snap-tab  54  is deformed inwardly until it snaps past the flange  64  and returns to its undeformed position, with the flange  64  secured above the shoulder  72  of the snap-tab  54 , thereby retaining the top deck  12  and the mid-top member  30  to the base  18 . 
     In the embodiment shown, the mid-top member  30  is secured to the top deck  12  prior to connection of the top deck  12  to the base  18  in the manner shown in  FIGS. 9   a - 9   b .  FIG. 9   a  is an enlarged view of the Area A of  FIG. 7   b , prior to connection of one of the ribs  46  to the mid-top member  30 . In this embodiment, the mid-top member  30  is vibration welded to the ribs  46  of the top deck  12 . During the vibration welding process, the projections  48  of the ribs  46  initially are brought into contact with the mid-top member  30 . Most of each projection  48  and a portion of the mid-top member  30  in contact with each projection  48  are melted during the vibration welding process to connect the mid-top member  30  to the top deck  12  with a weld  73  as shown in  FIG. 9   b , at which time there will still be a small gap between the ribs  46  the mid-top member  30  at areas other than the projection  48 , as shown. The top deck  12  and attached mid-top member  30  are then attached to base  18  in the snap-fit manner described above. 
     Variations on the pallet  10  could be made within the scope of the present invention. For example, some or all of the snap-tabs  54  could be switched to the base  18 . The ribs  46  could be molded with the mid-top member  30  instead of, or in addition to, being molded with the top deck  12 . 
     A pallet  110  according to a second embodiment of the present invention is shown in  FIGS. 10-16 . Components of the pallet  110  that are similar to the pallet  10  of  FIG. 1-9  are pre-appended with the numeral “1” and unless shown or described differently, the description of those components from above is hereby incorporated by reference. The pallet  110  includes a top deck  112  having a generally planar upper member  114  for supporting goods at a distance above the floor. The top deck  112  is secured to a base  118  having a plurality of columns  120  connected by runners  122 . 
       FIG. 11  is an exploded view of the pallet  110 . A mid-top member  130  is sandwiched between the top deck  112  and the base  118 . The mid-top member  130  has a plurality of openings  134 , including a center opening  134   a , side openings  134   b  and corner openings  134   c . The openings  134  correspond to and are aligned with the columns  120  of the base  118 . The columns  120  each include an upper portion  140  having a reduced outer dimension, thereby forming a shoulder  142  adjacent the upper portion  140 . 
       FIG. 12  is a bottom perspective partially exploded view of the top deck  112  and base  118 , with the mid-top member  130  mounted to the top deck  112 . The top deck  112  includes a plurality of column-receiving recesses  150 . A plurality of interior ribs  152  and snap-tabs  154  extend downward within each recess  150 . Short channel ribs  156  between the ribs  146  and the interior ribs  152  of each recess  150  define a channel  158 . 
       FIG. 13  is an enlarged perspective bottom view of a portion of the top deck  112 . The underside of the top deck  112  includes a plurality of intersecting, transverse ribs  146  extending downward. At each intersection of the ribs  146 , the ribs  146  are slightly taller to form downward projections  148 . A plurality (one shown) of snap-tabs  162  extend downward from the top deck  112  slightly further than the ribs  146 , for connecting the top deck  112  to the mid-top member  130 . The snap-tabs  162  on the top deck  112  are aligned with, and connect to, lips  174  on the mid-top member  130 , one of which is shown in  FIG. 14 . 
       FIG. 14  is a bottom perspective view of the mid-top member  130 . Recesses  176  at the intersections of the ribs  178  align with, and receive, the projections  148  on the top deck  112 , as shown in  FIG. 15 . 
       FIG. 15  is a sectional view through the mid-top member  130  connected to the top deck  112 . The projections  148  of the top deck  112  are received within corresponding recesses  176  in the mid-top member  130  in order to laterally align the top deck  112  and mid-top member  130 . The ribs  178  of the mid-top member  130  are aligned with and connected to the ribs  146  of the top deck  112 . The snap-tabs  162  of the top deck  112  snap into engagement with the lips  174  of the mid-top member  130  to retain the top deck  112  to the mid-top member  130 . 
     The top deck  112  and mid-top member  130  are then snap-fit assembled to the base  118  as shown in  FIG. 16 .  FIG. 16  is bottom perspective view of a diagonal section through the assembled pallet  110  of  FIG. 10 . As shown, the upper portion  140  of each column  120  is received in the channel  158  of one of the recesses  150  to abut the short channel ribs  156  and is also received within one of the openings  134  of the mid-top member  130 . The mid-top member  130  is disposed on the shoulder portions  142  of the columns  120 . Lips  164  on the columns  120  are snap-fittingly connected to the snap-tabs  154  on the top deck  112 . 
     Variations on the pallet  110  could be made within the scope of the present invention. For example, some or all of the snap-tabs  154  could be switched to the base  118 . Likewise, the locations of some or all of the snap-tabs  162  could be switched to the mid-top member  130 . 
     In both embodiments, the top deck  12 ,  112 , mid-top member  30 ,  130  and base  18 ,  118  are each separately molded preferably from polypropylene or other suitable material, such as HDPE, glass-filled nylon or other suitable materials via an injection-molding or other suitable process. 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

Technology Category: 7