Twin sheet pressure formed pallet

• US 6,389,989 B1
• Filed: 01/05/2001
• Issued: 05/21/2002
• Est. Priority Date: 01/05/2001
• Status: Expired due to Fees

• Current Assignee: PL Eagle, LLC
• Original Assignee: PL Eagle, LLC
• Inventors: Hagerty, James P.
• Primary Examiner(s): WILKENS, JANET MARIE
• Application Number:
  US09/754,137
• Time in Patent Office: 501 Days
• Field of Search: 108/901, 108/56.1, 108/56.3, 108/57.16, 108/57.25, 108/57.27, 108/57.29, 108/57.33
• US Class Current: 108/57.25
• CPC Class Codes: B65D 19/0036 forming discontinuous or non-planar contact surfaces
• CPC Class Codes: B65D 2519/00034 Plastic
• CPC Class Codes: B65D 2519/00069 Plastic
• CPC Class Codes: B65D 2519/00273 made of more than 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 2519/00333 contact surface having a stringer-like shape
• CPC Class Codes: B65D 2519/00338 contact surface having a discrete foot-like shape
• CPC Class Codes: B65D 2519/00407 on the load supporting surface
• CPC Class Codes: B65D 2519/00412 on the base surface
• CPC Class Codes: B65D 2519/00557 without separate auxiliary elements
• CPC Class Codes: B65D 2519/00562 chemical connection, e.g. glued, welded, sealed
• CPC Class Codes: B65D 71/0096 the dimensions of the supports corresponding to the periphery of the load, e.g. pallets
• CPC Class Codes: Y10S 108/901 Synthetic plastic industrial platform, e.g. pallet

Abstract

A pallet formed of a pair of thermoplastic sheets molded and fused together. The sheets have configurations that impart high stiffness and high strength, and the ability to be stacked on full pallets or nested on empty pallets. In particular, the molded configurations enable the sheets to be fused at a plurality of planes including mutually perpendicular planes for high strength union of the sheets. The pallet is especially suited for use with generally cubic milk crates.

Claims

1. A material handling pallet formed of upper and lower thermoplastic sheets, each of said sheets spanning horizontally over a generally rectangular area, the horizontal areas spanned by each sheet being generally coextensive, the sheets being fused together at distinct separate locations distributed throughout their respective areas, the upper sheet having a horizontal load supporting surface plane defined by substantially coplanar surface area portions that collectively represent an area that is a substantial fraction of its respective horizontally spanned area, the lower sheet having on a lower face zones adjacent to its perimeter and in its mid-section that are coplanar and that are adapted to transfer the weight of a load on the pallet to an underlying supporting medium, the sheets being interconnected by integrally molded legs, the sheets and legs being arranged to allow forks of a lift truck to pass between the upper and lower sheets, such that the forks pass below the upper sheet and above the lower sheet, to enable the forks to lift said pallet, said legs straddle areas that serve as fork entry channels, and said legs extend horizontally between said sheets along lines that are substantially continuous from locations adjacent one edge of the pallet to locations adjacent an opposite edge of the pallet.

2. A pallet as set forth in claim 1, wherein said legs are molded in the lower sheet.

3. A pallet as set forth in claim 2, wherein said legs have an inverted U-shape configuration that exists for a major portion of the horizontal length of the pallet measured in a direction parallel to a fork entry direction.

4. A pallet as set forth in claim 1, wherein said sheets are fused together in a plurality of planes.

5. A pallet as set forth in claim 4, wherein said planes of fusion include planes that are generally perpendicular to one another.

6. A pallet as set forth in claim 5, wherein said planes include three mutually generally perpendicular planes.

7. A pallet as set forth in claim 1, wherein said upper sheet is molded with stiffening grooves.

8. A pallet as set forth in claim 7, wherein the molded shapes of the upper and lower sheets define elongated fork entry passages extending in a direction parallel to opposite edges of the pallet, stiffening ribs molded into the upper sheet and extending over said passages in directions transverse to said entry passages.

9. A material handling pallet formed of upper and lower thermoplastic sheets, each of said sheets spanning horizontally over a generally rectangular area, the horizontal areas spanned by each sheet being generally coextensive, the sheets being fused together at distinct separate locations distributed throughout their respective areas, the upper sheet having a horizontal load supporting surface plane defined by substantially coplanar surface area portions that collectively represent an area that is a substantial fraction of its respective horizontally spanned area, the lower sheet having on a lower face zones adjacent to its perimeter and in its mid-section that are coplanar and that are adapted to transfer the weight of a load on the pallet to an underlying supporting medium, the sheets being interconnected by integrally molded legs, the sheets and legs being arranged to allow forks of a lift truck to pass between the upper and lower sheets, such that the forks pass below the upper sheet and above the lower sheet, to enable the forks to lift said pallet, said legs are molded in the lower sheet, said legs have an inverted U-shape configuration that exists for a major portion of the horizontal length of the pallet measured in a direction parallel to a fork entry direction, and said legs have pinch points in the form of narrowed zones with wall portions of the legs transverse to major wall portions of the legs at locations spaced along the horizontal lengths of the legs.

10. A material handling pallet formed of upper and lower thermoplastic sheets, each of said sheets spanning horizontally over a generally rectangular area, the horizontal areas spanned by each sheet being generally coextensive, the sheets being fused together at distinct separate locations distributed throughout their respective areas, the upper sheet having a horizontal load supporting surface plane defined by substantially coplanar surface area portions that collectively represent an area that is a substantial fraction of its respective horizontally spanned area, the lower sheet having on a lower face zones adjacent to its perimeter and in its mid-section that are coplanar and that are adapted to transfer the weight of a load on the pallet to an underlying supporting medium, the sheets being interconnected by integrally molded legs, the sheets and legs being arranged to allow forks of a lift truck to pass between the upper and lower sheets, such that the forks pass below the upper sheet and above the lower sheet, to enable the forks to lift said pallet, said upper sheet is molded with stiffening grooves, and said stiffening grooves are in a serpentine pattern when viewed from above the pallet.

11. A pallet as set forth in claim 10, wherein said bottom sheet is molded with stiffening embossments.

12. A pallet as set forth in claim 11, wherein said bottom sheet stiffening embossments are cruciform in shape.

13. A pallet as set forth in claim 12 wherein said cruciform embossments are spaced from one another by relatively small gaps.

14. A pallet as set forth in claim 11, wherein said lower sheet is molded with patterns adapted to be optionally cut out for clearance of the wheels of a floor jack.

15. A material handling pallet formed of upper and lower thermoplastic sheets, each of said sheets spanning horizontally over a generally rectangular area, the horizontal areas spanned by each sheet being generally coextensive, the sheets being fused together at distinct separate locations distributed throughout their respective areas, the upper sheet having a horizontal load supporting surface plane defined by substantially coplanar surface area portions that collectively represent an area that is a substantial fraction of its respective horizontally spanned area, the lower sheet having on a lower face zones adjacent to its perimeter and in its mid-section that are coplanar and that are adapted to transfer the weight of a load on the pallet to an underlying supporting medium, the sheets being interconnected by integrally molded legs, the sheets and legs being arranged to allow forks of a lift truck to pass between the upper and lower sheets, such that the forks pass below the upper sheet and above the lower sheet, to enable the forks to lift said pallet, and the upper sheet has a peripheral flange that extends above the plane of the horizontal load supporting surface, said peripheral flange being adapted to horizontally restrain goods stacked on said pallet.

16. A pallet as set forth in claim 15, wherein said pallet is substantially square.

17. A pallet as set forth in claim 16, wherein said pallet is sized to carry layers of standard milk crates in 3×

3 layers.

18. A pallet as set forth in claim wherein the bottom sheet has a peripheral configuration arranged to nest with the flange of the top sheet of an identical pallet.

19. A material handling pallet formed of upper and lower thermoplastic sheets, each of said sheets spanning horizontally over a generally rectangular area, the horizontal areas spanned by each sheet being generally coextensive, the sheets being fused together at distinct separate locations distributed throughout their respective areas, the upper sheet having a horizontal load supporting surface plane defined by substantially coplanar surface area portions that collectively represent an area that is a substantial fraction of its respective horizontally spanned area, the lower sheet having on a lower face zones adjacent to its perimeter and in its mid-section that are coplanar and that are adapted to transfer the weight of a load on the pallet to an underlying supporting medium, the sheets being interconnected by integrally molded legs, the sheets and legs being arranged to allow forks of a lift truck to pass between the upper and lower sheets, such that the forks pass below the upper sheet and above the lower sheet, to enable the forks to lift said pallet, said upper sheet is molded with stiffening grooves, the molded shapes of the upper and lower sheets define elongated fork entry passages extending in a direction parallel to opposite edges of the pallet, stiffening ribs molded into the upper sheet and extending over said passages in directions transverse to said entry passages, and said stiffening ribs have ends straddling said fork entry passages, said sheets having complementary plug and pocket areas where said sheets are fused in a plurality of planes perpendicular to one another.

20. A pallet formed of upper and lower thermoplastic molded sheets, the sheets having generally coextensive rectangular horizontally extending configurations, each of said sheets having a perimeter and having outer surface areas adjacent their perimeters, said sheets each having inner surface areas distributed at a plurality of locations inward of the outer surface areas including locations adjacent the center of the pallet, said outer surface areas and said inner surface areas of each sheet being substantially coplanar and defining a load supporting plane, the outer surface areas of each sheet being effectively continuous in its respective load supporting plane, integrally molded legs supporting said sheets in a manner such that portions forming said outer and inner surface areas are spaced vertically from one another with sufficient clearance and portions forming said legs are spaced horizontally from one another with sufficient clearance to permit entry of lift forks vertically between said sheet portions and horizontally between said legs, said upper sheet has a peripheral flange that extends above the plane of the horizontal load supporting surface, said peripheral flange being adapted to horizontally restrain goods stacked on said pallet.

21. A pallet as set forth in claim 20, wherein said legs are molded in said lower sheet.

22. A pallet as set forth in claim 21, wherein said legs extend in a fork entry direction across the major part of the width of the pallet.