Panel structure and pallet utilizing same

• US 5,390,467 A
• Filed: 03/14/1994
• Issued: 02/21/1995
• Est. Priority Date: 12/18/1992
• Status: Expired due to Term

• Current Assignee: Lyle H. Shuert
• Original Assignee: Lyle H. Shuert
• Inventors: Shuert, Lyle H.
• Primary Examiner(s): Friedman, Carl D.
• Assistant Examiner(s): STEPHAN, BETH A
• Application Number:
  US08/209,463
• Time in Patent Office: 344 Days
• Field of Search: 52/797, 52/571, 156/210, 156/292, 156/196, 156/293, 156/227, 156/308.4, 156/309.6, 264/510, 264/511, 264/545, 108/51.1, 108/90.1, 428/178-180
• US Class Current: 52/783.14
• CPC Class Codes: B29C 51/10 Forming by pressure difference, e.g. vacuum
• CPC Class Codes: B29C 51/267 Two sheets being thermoformed in separate mould parts and joined together while still in the mould B29C49/0691 takes precedence
• CPC Class Codes: B29D 24/002 formed with structures, e.g. cores placed between two plates or sheets, e.g. partially filled totally filled B29D99/0021
• CPC Class Codes: B65D 19/0002 Platforms, i.e. load supporting devices without provision for handling by a forklift
• CPC Class Codes: B65D 19/0012 forming a continuous plane contact surface
• CPC Class Codes: B65D 19/0018 and each contact surface having a discrete foot-like shape
• 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 2519/00278 the load supporting surface and the base surface being identical
• CPC Class Codes: B65D 2519/00288 made of one piece
• CPC Class Codes: B65D 2519/00293 made of more than one piece
• CPC Class Codes: B65D 2519/00318 made of one piece
• CPC Class Codes: B65D 2519/00323 made of more than one piece
• CPC Class Codes: B65D 2519/00338 contact surface having a discrete foot-like shape
• CPC Class Codes: B65D 2519/00343 contact surface being substantially in the form of a panel
• CPC Class Codes: B65D 2519/00378 whereby at least one spacer is made of two or more pieces
• CPC Class Codes: B65D 2519/00557 without separate auxiliary elements
• CPC Class Codes: B65D 2519/00567 mechanical connection, e.g. snap-fitted
• CPC Class Codes: B65D 2519/0094 nestable
• CPC Class Codes: Y10S 108/901 : Synthetic plastic industrial platform, e.g. pallet
• CPC Class Codes: Y10T 156/1002 : with permanent bending or reshaping or surface deformation of self sustaining lamina
• CPC Class Codes: Y10T 428/24661 : Forming, or cooperating to form cells
• CPC Class Codes: Y10T 428/24678 : Waffle-form

Abstract

A twin sheet plastic panel structure, a twin sheet plastic pallet utilizing the panel structure, and a methodology for forming the panel structure and pallet. The panel structure is formed by thermoforming an upper plastic sheet to include rows of hollow bosses extending downwardly from the main body of the sheet; thermoforming a lower plastic sheet to include rows of hollow bosses extending upwardly from the main body portion of the sheet; and bringing the sheets together while still in a heated flowable state to position the bosses of the upper sheet in intermeshing relation to the bosses of the lower sheet so that the annular side wall portions of the upper and lower bosses fuse together, the bottom walls of the upper sheet bosses are fused to the upper surface of the main body portion of the lower sheet, and the upper walls of the lower sheet bosses are fused to the lower surface of the main body portion of the upper sheet to form a series of parallel rigid column structures between the sheets. In the case of the pallet, the fused together upper and lower sheets coact to define a platform structure for the pallet and the upper and lower sheets further coact to define a plurality of legs extending downwardly from the platform structure to position the platform structure in spaced relation to a support surface.

Claims

1. A twin sheet panel structure comprising an upper plastic sheet including a planar main body portion having upper and lower surfaces and a lower plastic sheet positioned in parallel spaced relation below said upper plastic sheet and including a main body portion having upper and lower surfaces, the upper sheet further including a plurality of spaced hollow bosses opening in the upper surface of the upper sheet main body portion and each including an annular side wall portion extending downwardly from the lower surface of said upper sheet main body portion and a lower wall portion at a lower end of the side wall portion, the lower plastic sheet further including a plurality of spaced hollow bosses opening in the lower surface of the lower sheet main body portion and each including an annular side wall portion extending upwardly from the upper surface of the lower sheet main body portion and an upper wall portion at an upper end of the side wall portion, characterized in that:

the annular side wall portions have a generally circular cross-sectional configuration;

the combined area of the openings of the downwardly extending bosses of the upper sheet in the upper surface of the upper sheet main body portion constitutes less than half of the total surface area of the upper surface of the main body portion of the upper sheet;

the combined area of the openings of the upwardly extending bosses of the lower sheet in the lower surface of the lower sheet main body portion constitutes less than half of the total surface area of the lower surface of the main body portion of the lower sheet; and

the annular side wall portions of some of said upper sheet bosses are fused to the annular side wall portions of some of said lower sheet bosses.

2. A panel structure according to claim 1 wherein the lower wall portions of the upper sheet bosses are positioned in contiguous spaced relation on the upper surface of the main body portion of the lower sheet and the upper wall portions of the lower sheet bosses are positioned in contiguous spaced relation on the lower surface of the main body portion of the upper sheet.

3. A panel structure according to claim 2 wherein the lower wall portions of the upper sheet bosses are fused to the upper surface of the main body portion of the lower sheet and the upper wall portions of the lower sheet bosses are fused to the lower surface of the main body portion of the upper sheet.

4. A panel structure according to claim 1 wherein at least some of said downwardly extending bosses on said upper sheet are positioned in spaces between adjacent upwardly extending bosses on said lower sheet.

5. A panel structure according to claim 1 wherein the upper sheet bosses are arranged in a defined grouping with the bosses in the grouping spaced from each other, the lower sheet bosses are arranged in a defined grouping complementary to the upper sheet grouping with the bosses in the lower sheet grouping spaced from each other, and the bosses in the upper sheet grouping fit in complementary fashion into spaces between the bosses in the lower sheet grouping with the side wall portions of the upper sheet bosses fused to the side wall portions of the lower sheet bosses.

6. A panel structure according to claim 1 wherein the fused together upper sheet bosses and lower sheet bosses are arranged in parallel rows with each row including alternate upper sheet bosses and lower sheet bosses.

7. A panel structure according to claim 1 wherein the annular side wall portions of said first and second sheet bosses taper inwardly in complementary fashion so as to define angled interfaces therebetween and said side wall portions are fused together at their angled interfaces.

8. A twin sheet panel structure comprising an upper plastic sheet including a planar main body portion having upper and lower surfaces and a plurality of spaced hollow bosses opening in the upper surface of the main body portion and each including an annular side wall portion extending downwardly from the lower surface of the main body portion and a lower wall portion at lower end of the side wall portion, and a lower plastic sheet including a planar main body portion having a lower surface, and an upper surface fused to the lower wall portions of said upper sheet bosses, and a plurality of spaced hollow bosses opening in the lower surface of the lower sheet main body portion and each including an annular side wall portion extending upwardly from the upper surface of the lower sheet main body portion and an upper wall portion at an upper end of the side wall portion, said upper wall portions of said lower sheet bosses being fused in spaced relation to the lower surface of said upper sheet main body portion, characterized in that:

the annular side wall portions have a generally circular cross-sectional configuration;

the combined area of the openings of the downwardly extending bosses of the upper sheet in the upper surface of the upper sheet main body portion constitutes less than half of the total surface area of the upper surface of the main body portion of the upper sheet;

the combined area of the opening of the upwardly extending bosses of the lower sheet in the lower surface of the lower sheet main body portion constitutes less than half of the total surface area of the surface of the main body portion of the lower sheet; and

side wall portions of upper sheet bosses are arranged in contiguous relation to side wall portions of lower sheet bosses with the contiguous side wall portions fused together.

9. A panel structure according to claim 8 wherein the annular side wall portions of said upper and lower sheet bosses taper inwardly in complementary fashion so as to define angled interfaces therebetween and said side wall portions are fused together at their angled interfaces.

10. A twin sheet panel structure comprising a first plastic sheet including a planar main body portion having inner and outer surfaces and a second plastic sheet positioned in parallel spaced relation to said first plastic sheet and including a main body portion having an outer surface and an inner surface confronting the inner surface of the main body portion of said first sheet, characterized in that the first plastic sheet further includes a plurality of generally parallel laterally extending rows of hollow bosses opening in the outer surface of the first sheet main body portion with the bosses in each row laterally spaced from each other and with each boss including an annular side wall portion extending inwardly from the inner surface of the first sheet and an inner wall portion at the inner end of the side wall portion, the second plastic sheet further includes a plurality of generally parallel laterally extending rows of hollow bosses opening in the outer surface of the second sheet main body portion with the bosses in each row laterally spaced from each other and with each boss including an annular side wall portion extending inwardly from the inner surface of the second sheet and an inner wall portion at the inner end of the side wall portion, the annular side wall portions have a generally circular cross-sectional configuration, the combined area of the openings of the inwardly extending bosses of the first sheet in the outer surface of the main body portion of the first sheet constitutes less than half of the total surface area of the outer surface of the main body portion of the first sheet, the combined area of the openings of the inwardly extending bosses of the second sheet in the outer surface of the second sheet main body portion constitutes less than half of the total surface area of the outer surface of the main body portion of the second sheet, and the bosses in a row of said first sheet are interdigitated with the bosses in a corresponding row of the second sheet with the adjacent side wall portions of the interdigitated bosses fused together to form a plurality of rigid column structures between the sheets corresponding to said rows.

11. A panel structure according to claim 10 wherein the inner wall portion of each boss of said first sheet is fused to the inner surface of the main body portion of said second sheet and the inner wall portion of each boss of said second sheet is fused to the inner surface of the main body portion of said first sheet.

12. A twin sheet plastic pallet comprising an upper plastic sheet including a planar main body portion having an upper surface defining a load receiving surface and a lower plastic sheet positioned in downwardly spaced relation below the upper plastic sheet and including a main body portion having a lower surface, the upper sheet further including a plurality of spaced hollow bosses opening in the upper surface of the upper sheet main body portion and each including an annular side wall portion extending downwardly from said upper sheet main body portion and a bottom wall portion at the lower end of said side wall portion fused to the upper surface of the main body portion of said lower sheet, and the lower plastic sheet further including a plurality of spaced hollow bosses opening in the lower surface of the lower sheet main body portion and each including an annular side wall portion extending upwardly from said lower sheet main body portion and a top wall portion at the upper end of said side wall portion fused to the lower surface of said upper sheet main body portion, characterized in that:

the annular side wall portions have a generally circular cross-sectional configuration, the annular side wall portions of some of the upwardly extending bosses are fused to the annular side wall portions of some of the downwardly extending bosses, the combined area of the openings of the downwardly extending bosses of the upper sheet in the upper surface of the upper sheet main body portion constitutes less than half of the total surface area of the upper surface of the main body portion of the upper sheet, and the combined area of the openings of the upwardly extending bosses of the lower sheet in the lower surface of the lower sheet main body portion constitutes less than half of the total surface area of the lower surface of the main body portion of the lower sheet.

13. A pallet according to claim 12 wherein at least some of the upwardly extending bosses are positioned in spaces between adjacent downwardly extending bosses.

14. A pallet according to claim 12 wherein the fused together upwardly extending bosses and downwardly extending bosses are arranged in parallel rows.

15. A pallet according to claim 12 wherein the annular side wall portions of said upper and lower sheet bosses taper inwardly in complementary fashion so as to define angled interfaces therebetween and said side wall portions are fused together at their angled interfaces.

16. A pallet according to claim 12 wherein said fused together upper and lower sheets coact to define a platform structure of said pallet and said pallet further includes a plurality of spaced legs extending downwardly from said platform structure.

17. A twin sheet plastic pallet including an upper plastic sheet including a planar main body portion having upper and lower surfaces and a lower plastic sheet positioned in downwardly spaced relation below the upper plastic sheet and including a main body portion having upper and lower surfaces, characterized in that the upper plastic sheet further includes a plurality of hollow bosses opening in the upper surface of the first sheet main body portion with the bosses arranged in a defined grouping of spaced bosses and with each boss including an annular side wall portion extending downwardly from the lower face of the upper sheet main body portion and a bottom wall portion at the lower end of the side wall portion, the lower plastic sheet further includes a plurality of hollow bosses opening in the lower surface of the second sheet main body portion with the bosses arranged in a defined grouping complementary to the defined grouping of the upper sheet bosses and with each boss including an annular side wall portion extending upwardly from the upper surface of the main body portion of the lower sheet and a top wall portion at the upper end of the side wall portion, the annular side wall portions have a generally circular cross-sectional configuration, the bosses in the defined grouping of upper sheet bosses are interdigitated with respect to the complementary defined grouping of lower sheet bosses with the adjacent side wall portions of the interdigitated bosses fused together to form a rigid structure between the upper and lower sheets corresponding to the interdigitated defined groupings, the combined area of the openings of the downwardly extending bosses of the upper sheet in the upper surface of the upper sheet main body portion constitutes less than half of the total surface area of the upper surface of the main body portion of the upper sheet, and the combined area of the openings of the upwardly extending bosses of the lower sheet in the lower surface of the lower sheet main body portion constitutes less than half of the total surface area of the lower surface of the main body portion of the lower sheet.

18. A pallet according to claim 17 wherein the bottom wall of each boss of said upper sheet is fused to the upper surface of the main body portion of said lower sheet and the top wall of each boss of said lower sheet is fused to the lower surface of the main body portion of said upper sheet.

19. A pallet according to claim 17 wherein the fused together upper and lower sheets coact to define a platform structure of said pallet and said pallet further includes a plurality of spaced legs extending downwardly from said platform structure.

20. A pallet according to claim 19 wherein said pallet further includes a base structure secured to the lower ends of said legs so that said legs, said platform structure, and said base structure coact to define passageways for the receipt of material handling equipment.

21. A pallet according to claim 20 wherein said base structure has a construction corresponding to the construction of said platform structure and including upper and lower sheets respectively defining downwardly extending and upwardly extending interdigitated bosses with the side walls of at least some of the upwardly extending bosses fused to the side walls of some of the downwardly extending bosses.

22. A pallet according to claim 21 wherein said legs are formed of panel structures having upper and lower sheets respectively defining upwardly and downwardly extending hollow bosses arranged in interdigitated fashion with annular side wall portions of some of the upwardly extending bosses fused to annular side wall portions of some of the downwardly extending bosses.

23. A pallet according to claim 21 wherein some of the upwardly and downwardly extending bosses of the upper and lower sheets respectively of the platform structure are larger than the remaining upwardly and downwardly extending bosses of the platform structure and these larger bosses are intermeshingly fused together to form leg structures.

24. A pallet according to claim 23 wherein some of the upwardly and downwardly extending bosses of the upper and lower sheets respectively of the base structure are larger than the remaining upwardly and downwardly extending bosses of the base structure, these larger bosses are intermeshingly fused together to form leg structures, and the platform structure leg structures are fused to the base structure leg structures to form the legs.

25. A pallet according to claim 17 wherein the annular side wall portions of said upper and lower sheet bosses taper inwardly in complementary fashion so as to define angled interfaces therebetween and said side wall portions are fused together at their angled interfaces.