Double deck fold-up pallet

• US 5,950,546 A
• Filed: 12/13/1996
• Issued: 09/14/1999
• Est. Priority Date: 12/13/1996
• Status: Expired due to Fees

• Current Assignee: Wilbert Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: TriEnda Corporation (Newell Brands Inc.)
• Inventors: Noble, Jamie E., Brown, Henry F.
• Primary Examiner(s): Cuomo, Peter M.
• Assistant Examiner(s): WILKENS, JANET MARIE
• Application Number:
  US08/763,369
• Time in Patent Office: 1,005 Days
• Field of Search: 108/51.11, 108/901, 108/51.3, 108/56.1, 108/56.3, 108/57.29, 108/57.33
• US Class Current: 108/56.1
• CPC Class Codes: B65D 19/0012 forming a continuous plane contact surface
• CPC Class Codes: B65D 2519/00034 Plastic
• CPC Class Codes: B65D 2519/00069 Plastic
• CPC Class Codes: B65D 2519/00104 Plastic
• CPC Class Codes: B65D 2519/00268 made of one piece
• CPC Class Codes: B65D 2519/00288 made of one piece
• CPC Class Codes: B65D 2519/00318 made of one piece
• CPC Class Codes: B65D 2519/00343 contact surface being substantially in the form of a panel
• CPC Class Codes: B65D 2519/00562 chemical connection, e.g. glued, welded, sealed
• CPC Class Codes: B65D 2519/00572 with separate auxiliary element, e.g. screws, nails, bayonets
• CPC Class Codes: B65D 2519/0087 collapsible pallet
• CPC Class Codes: Y10S 108/901 Synthetic plastic industrial platform, e.g. pallet

Abstract

A single twin-sheet thermoformed plastic part has parallel bands of plastic forming fillets which allow stiff pallet deck segments to be folded after forming and locked together into a support structure with a planar upper deck spaced above a pallet lower deck with openings for lift truck tines. The lower deck has two segments joined by side stringers to the upper deck. Two central stringer segments extend along folding fillets from lower deck half segments to lock into place with the upper deck. The pallet is locked in its assembled configuration by a rod which passes through knuckles formed beneath the central stringers. The monocoque construction of the pallet provides for advantageous stiffness and load support capacity, while at the same time being economical to produce. For increased load-carrying capability, the pallet may be formed with a reinforcing substrate reinforced with a tubular steel insert. The pallet has interleaved step structure adjacent each plastic fillet which transfers vertical loads and also resists lateral deformation of the pallet.

Claims

1. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment, wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment, and along a first upper plastic fold region from the upper deck, wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment, the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer and the first center stringer engages and is fastened to the second center stringer, and the first lower deck segment is connected to the second lower deck segment adjacent the first center stringer and the second center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet.

2. The pallet of claim 1 wherein each center stringer has at least one projecting bayonet which extends into portions of the upper deck defining bayonet-receiving slots.

3. The pallet of claim 2 wherein the bayonets extend from each of the center stringers such that the bayonets extend in adjacent relation to each other within the bayonet-receiving slots in the upper deck.

4. The pallet of claim 2 wherein tapered barbs are formed on the end of each bayonet, such that the bayonets will be retained in a snap-fit within the bayonet receiving slots in the upper deck.

5. The pallet of claim 1 wherein each center stringer has a plurality of connecting members which protrude from the stringers into portions of the upper deck which define mating pockets, the connecting members engaging with the mating pockets to restrict axial shifting of the center stringers with respect to the upper deck.

6. The pallet of claim 1 wherein the horizontal width of the side stringers is at most approximately the width of a standard wooden 2×

4 beam.

7. The pallet of claim 1 wherein the upper deck has a plurality of pockets formed therein which are approximately eight times as long as they are wide, and which extend from an underside of the upper deck to the top surface of the upper deck, the pockets being arranged in a pattern which follows the anticipated load patterns of the upper deck.

8. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment, wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment, and along a first upper plastic fold region from the upper deck, wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment, the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet, wherein the first center fold region has portions defining a plurality of knuckles, and the second center fold region has portions defining a plurality of knuckles which interleave with the first center fold region knuckles, and wherein a rod is inserted through the interleaved knuckles to prevent the separation of the first center stringer from the second center stringer.

9. A pallet comprising:

a twin-sheet thermoformed upper deck having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment and along a first upper plastic fold region from the upper deck wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment. the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet, wherein the upper deck has at least one downwardly opening channel, and wherein each center stringer has at least one protruding bayonet with portions defining a concave recess, such that adjacent bayonets extend within the upper deck channel such that the concave recesses face one another, and wherein a rod pierces a wall in the upper deck and passes through the concave recesses in the center stringers to restrain escape of the center stringers from the channel.

10. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment, wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment, and along a first upper plastic fold region from the upper deck, wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment, the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer and the first lower deck segment is connected to the second lower deck segment adjacent the first center stringer and the second center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet, and wherein the upper deck has at least one downwardly opening channel, and wherein each center stringer has portions which protrude into the channel, and wherein a rod pierces a plurality of walls in the upper deck and passes through the center stringer protruding portions to restrain escape of the center stringers from the channel.

11. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment, wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment, and along a first upper plastic fold region from the upper deck. wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment, the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet, wherein interlocking teeth are formed on the side stringers across the fold regions from teeth formed on the upper deck, such that the upper deck teeth engage with the stringer teeth to carry vertical loads from the upper deck to the stringers, and to resist lateral loads.

12. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment, wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment, and along a first upper plastic fold region from the upper deck, wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment, the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet, wherein interlocking teeth are formed on the side stringers across the fold regions from teeth formed on the lower deck segments, such that the lower deck segment teeth engage with the stringer teeth to carry vertical loads from the stringers to the lower deck segments, and to resist lateral loads.

13. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a first twin-sheet thermoformed lower deck segment;

a second twin-sheet thermoformed lower deck segment, wherein the first lower deck segment and the second deck segment together comprise a lower deck which is disposed beneath and substantially parallel to the upper deck;

a first twin-sheet thermoformed side stringer extending along a first lower integral plastic fold region from the first lower deck segment, and along a first upper plastic fold region from the upper deck, wherein the first lower plastic fold region is substantially parallel to the first upper plastic fold region;

a second twin-sheet thermoformed side stringer extending along a second lower integral plastic fold region from the second lower deck segment, and along a second upper integral plastic fold region from the upper deck, wherein the second lower plastic fold region is substantially parallel to the second upper plastic fold region;

a first twin-sheet thermoformed center stringer extending along a first center fold region from the first lower deck segment, the first center stringer having portions which engage with the upper deck, such that the first center stringer is substantially parallel to the first side stringer and the second side stringer; and

a second twin-sheet thermoformed center stringer extending along a second center fold region from the second lower deck segment, the second center stringer having portions which engage with the upper deck, such that the second center stringer is substantially parallel to the first side stringer and the second side stringer, and wherein the second center stringer extends in close relationship to the first center stringer, the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single twin-sheet thermoformed part and are assembled by folding into a pallet, wherein the center stringers are connected to the lower deck segments by a plurality of bendable strips of plastic, and wherein the bendable strips extending from the the first lower deck segment are positioned adjacent the bendable strips extending from the second lower deck segment, and the bendable strips wrap around a connecting member which extends therebetween, the connecting member thereby preventing the first center stringer from separating from the second center stringer.

14. The pallet of claim 13 wherein the connecting member is a cylindrical rod.

15. The pallet of claim 14, whrerein the rod is comprised of a material selected from the group consisting of steel, fiberglass, plastic, composite fiber and resin.

16. A pallet employing monocoque structure comprising:

a twin-sheet thermoformed upper deck, having a substantially planar top surface defining the structure outer fiber;

a twin-sheet thermoformed lower deck, comprised of two adjacent lower deck segments spaced parallel to and beneath the upper deck;

a first twin-sheet thermoformed side stringer, which extends between the upper deck and the lower deck;

a second twin-sheet thermoformed side stringer, which extends between the upper deck and the lower deck, wherein the first side stringer and the second side stringer are fixed to both the upper deck and the lower deck to transfer loads from the upper deck to the lower deck and to resist lateral loads;

two twin-sheet thermoformed center stringers which are positioned laterally between the first side stringer and the second side stringer and which extend between the upper deck and the lower deck, wherein one of the two center stringers extends from each of the two adjacent lower deck segments, the two center stringers being connected together at the lower deck; and

interlocking structure formed on the upper deck which engages with protruding structure on the two center stringers to resist displacement of the center stringers with respect to the upper deck.

17. The pallet of claim 16 wherein the two center stringers extend from the two adjacent lower deck segments along a common line and the lower deck segments and the center stringers are connected together along said common line.

18. The pallet of claim 17 wherein the first side stringer and the second side stringer extend from the upper deck along foldable plastic fillets, and wherein the lower deck segments extend from the side stringers along foldable plastic fillets.

19. The pallet of claim 17 wherein the protruding structure on the two center stringers comprises a projecting connecting member on each of the two center stringers which extends into recessed portions of the upper deck defined by the interlocking structure formed on the upper deck, the connecting members engaging with the recessed portions to restrict axial shifting of the two center stringers with respect to the upper deck.

20. The pallet of claim 19 wherein each projecting connecting member defines a bayonet which extends from each of the center stringers such that the bayonets extend in adjacent relation to each other within slots defined within the recessed portions on the upper deck.

21. The pallet of claim 16 wherein the upper deck top surface is substantially unbroken by depressions, and wherein each lower deck segment has a lower surface which is generally planar and unbroken.

22. The pallet of claim 16 wherein each of the twin-sheet thermoformed upper deck, lower deck, side stringers and center stringers have a plurality of elongated ribs formed therein extending between a first sheet of thermoplastic material and a second sheet of thermoplastic material.

23. A pallet employing monocoque structure comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface defining the structure outer fiber;

a twin-sheet thermoformed lower deck, spaced parallel to and beneath the upper deck;

a first twin-sheet thermoformed side stringer, which extends between the upper deck and the lower deck;

a second twin-sheet thermoformed side stringer, which extends between the upper deck and the lower deck, wherein the first side stringer and the second side stringer are fixed to both the upper deck and the lower deck to transfer loads from the upper deck to the lower deck and to resist lateral loads;

two twin-sheet thermoformed center stringers, each of which is positioned laterally between the first side stringer and the second side stringer and which extends between the upper deck and the lower deck, wherein each of the twin-sheet thermoformed upper deck, lower deck, side stringers and center stringers have a plurality of elongated ribs formed therein extending between a first sheet of thermoplastic material and a second sheet of thermoplastic material; and

interlocking structure formed on the upper deck which engages with protruding structure on each of the center stringers to resist displacement of the center stringers with respect to the upper deck, wherein the two center stringers extend from two parallel lower deck segments which comprise the lower deck, and each center stringer has a projecting connecting member which extends into recessed portions of the upper deck, the connecting members engaging with the recessed portions to restrict axial shifting of the center stringers with respect to the upper deck; and

wherein the two center stringers extend from the lower deck segments along a plurality of knuckles, and the knuckles of each center stringer interleave, and a rod is inserted through the interleaved knuckles to prevent the separation of the two center stringers.

24. A thermoformed part for assembly into a pallet comprising:

a thermoformed upper deck, having a generally planar top surface;

a first thermoformed lower deck segment;

a second thermoformed lower deck segment;

a first thermoformed side stringer which extends along a first lower fillet from the first lower deck segment, and along a first upper fillet from the upper deck, wherein the first lower fillet is substantially parallel to the first upper fillet;

a second thermoformed side stringer extending along a second lower fillet from the second lower deck segment, and along a second upper fillet from the upper deck, wherein the second lower fillet is substantially parallel to the second upper fillet;

a first thermoformed center stringer extending along a first center fillet from the first lower deck segment, the first center stringer having portions which protrude outwardly away from the first center fillet;

a second thermoformed center stringer extending along a second center fillet from the second lower deck segment, the second center stringer having portions which protrude outwardly away from the second center fillet; and

portions of the upper deck which define a depression positioned to receive portions of the center stringers when the center stringers are folded to engage the upper deck, wherein the upper deck, the first lower deck segment, the second lower deck segment, the first side stringer, the second side stringer, the first center stringer, and the second center stringer are formed as a single thermoformed part and extend substantially parallel to one another and are disposed to be folded into a pallet, and wherein all the fillets are parallel bands of plastic which extend in a straight line, so that the fillets in an assembled pallet are outwardly positioned on the pallet.

25. A pallet comprising:

a twin-sheet thermoformed upper deck, having a generally planar top surface;

a twin-sheet thermoformed lower deck, spaced parallel to and beneath the upper deck;

a first twin-sheet thermoformed side stringer, which extends between the upper deck and the lower deck;

a second twin-sheet thermoformed side stringer, which extends between the upper deck and the lower deck, wherein the first side stringer and the second side stringers are fixed to both the upper deck and the lower deck to transfer loads from the upper deck to the lower deck and to resist lateral loads;

two twin-sheet thermoformed center stringers which are positioned laterally between the first side stringer and the second side stringer and which extend between the upper deck and the lower deck; and

interlocking structure formed on the upper deck which engages with protruding structure on the center stringer to resist displacement of the center stringer with respect to the upper deck; and

means for resisting deflection of the side stringers with respect to the upper deck and the lower deck formed on the side stringers, the resisting means comprising teeth which protrude from the side stringers to engage teeth formed on the decks.