Shipping pallet and container
This is a continuation-in-part of application Ser. No. 295,524, filed Aug. 24, 1981 now U.S. Pat. No. 4,413,737, a continuation-in-part of application Ser. No. 229,195 filed Jan. 28, 1981, now abandoned. 
    
    
     In the above-identified parent application, there is disclosed a shipping pallet of the type formed of a single sheet of plastic material, and which is adapted to be used with another like pallet to form a shipping container. Specifically, the shipping container is composed of a central sleeve having a pallet secured to each of the top and bottom edges of the sleeve, and with the pallets disposed in opposite orientations. 
     The pallet of the prior application comprises a generally planar base and a plurality of foot members projecting from one side of the base and being adapted to act as vertical supporting legs. The projecting foot members are so configured and so arranged relative to each other such that a plurality of the pallets may be nested, and such that a pair of oppositely disposed pallets may be stacked in mating relation with respect to each other, with the projecting foot members serving to provide a lateral anti-shift interengagement. A rim extends peripherally around the base on the side opposite the foot means, and a sleeve receiving groove is provided alongside the rim. To form a shipping container, a sleeve is mounted between two oppositely disposed pallets, with the ends of the sleeve disposed in respective sleeve receiving grooves of the pallets, and with the foot members of the two pallets projecting outwardly in opposite directions. Strapping bands are employed for maintaining the assembly of the components. 
     The above-described pallet is seen to represent a substantial advance in the art, and has enjoyed substantial commercial success. However, the use of the pallet has been somewhat limited by the fact that it is able to mate with a sleeve of only one cross-sectional configuration, namely, a four-sided rectangular sleeve. This limitation restricts the flexibility of use of the pallet, and in addition, the four-sided sleeve utilized with the pallet is somewhat weak in load bearing capacity. 
     It is accordingly an object of the present invention to provide a pallet of the described type which is adapted to mate with sleeves of different cross-sectional configurations, to thereby permit shipping containers to be formed which have different configurations. 
     It is a more particular object of the present invention to provide a pallet of the described type and which is adapted to selectively mate with either a four-sided rectangular sleeve, or an eight-sided octagonal sleeve, to thereby permit use of the octagonal sleeve where increased load bearing capacity is required. 
     It is still another object of the present invention to provide a method of efficiently producing shipping containers composed of a sleeve and two like pallets disposed at the respective ends of the sleeve, wherein the pallets may be readily gripped and handled by a cooperating gripping device, and wherein shipping containers may be selectively produced which have different cross-sectional configurations while utilizing a common pallet design. 
     These and other objects and advantages of the present invention are achieved in the embodiments illustrated herein by the provision of a pallet of unitary construction and which is composed of a single sheet of material and comprises a base and a plurality of spaced-apart foot means projecting from a common side of the base. In addition, the pallet includes a first sleeve receiving groove provided adjacent the periphery of the pallet and on the side opposite the foot means, and a second sleeve receiving groove provided on the same side of the pallet as the first groove and positioned so as not to extend outwardly beyond the confines of the first groove. The second groove is constructed and arranged so as to receive a sleeve therein of different cross-sectional configuration than the sleeve which is adapted to be received in the first groove. 
     The pallet of the present invention is adapted to form a shipping container which is able to be stacked in mating relation with other shipping containers of substantially the same construction. More particularly, the shipping container comprises upper and lower pallets which are inverted relative to each other, with a sleeve extending between and positioned in engagement with the upper and lower pallets. In addition, the foot means of the two pallets each comprise at least one projecting member and a platform member adjacent each projecting member, with the platform members and projecting members being so constructed and arranged relative to each other that the projecting members of each pallet are adapted to abut the platform members of a pallet of an adjacent shipping container for providing a lateral anti-shift interengagement between the adjacent stacked containers. 
     The preferred embodiment of the pallet also includes a plurality of substantially flat areas which are present on each side of the pallet, and which are adapted for engagement by a suction device or the like for facilitating the handling and assembly of the pallets into shipping containers. Also, in the preferred embodiment, at least some of the spaced-apart foot means comprise a pair of spaced-apart projecting members and a pair of spaced-apart platform members and a bridging member interconnecting each of the pairs of projecting members for strengthening the same. 
     The present invention also involves a method of producing shipping containers which involves the steps of providing first and second stacks of pallets of the construction described above, and wherein the pallets of the second stack are inverted relative to the pallets of the first stack. The uppermost pallet is removed from the first stack and positioned on a supporting surface, and a sleeve is selected from a supply of sleeves having a cross-sectional configuration corresponding to one of the first and second sleeve receiving grooves of the pallet. The selected sleeve is positioned in the correspondingly configured one of the first and second grooves, and after the product has been deposited in the sleeve, the uppermost inverted pallet from the second stack is positioned on top of the sleeve so that the upper end of the sleeve is positioned within the correspondingly configured sleeve receiving groove of the inverted pallet. The assembly is then bindingly interconnected, with the ends of the sleeve thus being positioned in the respective grooves of the upper and lower pallets. 
    
    
     Some of the objects having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings in which 
     FIG. 1 is a perspective view of a shipping container which embodies the features of the present invention; 
     FIG. 2 is an exploded perspective view of the container shown in FIG. 1; 
     FIG. 3 is a perspective view of a second embodiment of a shipping container in accordance with the present invention; 
     FIG. 4 is an exploded perspective view of the container shown in FIG. 3; 
     FIG. 5 is a side-elevation view of a stack of shipping containers in accordance with the embodiment of FIG. 1; 
     FIG. 6 is a fragmentary sectional side elevation view of a plurality of the pallets of the present invention in a nested relation; 
     FIG. 7 is a top perspective view of the pallet of the present invention; 
     FIG. 8 is a side elevation view of the pallet shown in FIG. 7, viewed from any one of the four sides thereof; 
     FIG. 9 is a bottom perspective view of the pallet; 
     FIG. 10 is a top plan view of the pallet; 
     FIGS. 11-14 are sectional side elevation views of the pallet and taken substantially along the lines 11--11, 12--12, 13--13, and 14--14 respectively, of FIG. 10; 
     FIG. 15 is fragmentary top plan view showing one-quarter of the pallet; 
     FIG. 16 is a fragmentary sectional side elevation view taken substantially along the lines 16--16 of FIG. 15; 
     FIG. 17 is a schematic illustration of the steps involved in the method of producing shipping containers in accordance with the present invention; and 
     FIGS. 18 and 19 are schematic illustrations of the steps of removing individual pallets from each of the two stacks of pallets involved in the method of FIG. 17. 
    
    
     Referring more specifically to the drawings, a pallet which incorporates the features of the present invention is illustrated generally at 20. The illustrated embodiment of the pallet is composed of a unitary sheet of molded plastic material, and may be formed by a conventional vacuum molding process. Also, the illustrated pallet is generally square in plan view, and it includes a base 22, and a plurality of spaced-apart foot means projecting from a common side of the base. 
     As best seen in FIG. 9, the foot means includes corner foot means 24 positioned in respective corner areas of the pallet, central foot means 25 positioned centrally of the pallet, and intermediate foot means 26 positioned between adjacent corner foot means. As best seen in FIG. 10, the corner foot means 24 includes a single projecting member of generally triangular cross-sectional outline, and an adjacent platform 24a of a similar outline. The central foot means 25 comprises four projecting members disposed in a staggered non-aligned array, and four adjacent platforms 25a. The intermediate foot means 26 each comprises two projecting members, and two adjacent platforms 26a. Also, a bridging member 25b interconnects the four projecting members of the central foot means for strengthening the same, with the bridging member 25b projecting from the base a lesser distance than each of the four projecting members. Similarly, a bridging member 26b interconnects the two projecting members of each of the intermediate foot means 26. 
     As will be apparent from the various views, the projecting members are configured so as to permit the pallets to be nested in the manner shown in FIG. 6. Also, the projecting members are adapted to abut respective platform members of an adjacent, inverted pallet, so as to provide lateral interengagement between the two pallets which prevents lateral shifting therebetween. Thus, a number of containers 28 may be vertically stacked as shown in FIG. 5, with the projecting members effectively precluding lateral shifting between the containers. Since each quarter of the pallet (as shown in FIG. 15) is identical with each other quarter, the vertically adjacent containers may be stacked in any orientation with respect to each other. Stated in other words, each pallet of the container may be reoriented at any other position of orientation of an integral multiple of 90° out-of-phase from its previous stacked position relative to the adjacent containers. 
     It will also be apparent that the projecting members of all of the foot means are arranged in such spaced relationship so as to provide a first pair of spaced parallel passages represented by the dashed lines 30 in FIG. 9, extending along opposite sides of a centerline passing through the pallet, and a second pair of spaced parallel passages, represented by the dashed lines 32 in FIG. 9, extending transversely of the first named passages, with the passages of each pair being arranged to accommodate the arms of a forklift type transporting vehicle or of a handtruck. The pallet further includes a channel 34 extending along each of the passages for receiving a strapping band 35, and grippable means in the form of four flat areas 38 positioned in the passages and adapted for engagement by suction devices or the like for facilitating the handling and assembly of the pallets into shipping containers, as hereinafter further described. The four flat areas 38 are disposed symmetrically about the center of the pallet, with each being approximately midway between the center and one of the corners. Also, the four flat areas are present on each side of the pallet, note FIGS. 18 and 19. 
     In accordance with the present invention, the pallet 20 further includes a peripheral rim 40 extending outwardly from the base on the side opposite the foot means. In addition, the rim 40 partially defines a first square sleeve receiving groove 42 which extends about the periphery of the pallet. The pallet also includes a second sleeve receiving groove on the same side of the pallet and positioned so as not to extend outwardly beyond the confines of the first groove. The second groove is indicated by the dashed lines in FIGS. 10 and 15, and is octagonal in outline and concentrically arranged relative to the first groove and relative to the pallet. More particularly, the second groove includes first linear portions 44a which coincide with linear portions of the first groove, and second portions 44b which cut diagonally across the corners of the pallet. Thus the first and second sleeve receiving grooves not only have coinciding linear portions and are concentrically arranged relative to each other and relative to the pallet, but additionally each groove as shown encompasses at least a major portion of the pallet, and further wherein the grooves are of different size and geometric shape from each other. A large portion of the base of the pallet includes rows of integrally molded reinforcing ribs 46, with some groupings of ribs extending in one direction and other groupings extending at right angles to the first groupings. 
     A shipping container 28 which embodies the features of the present invention is illustrated in FIG. 1, and which comprises upper and lower pallets 20 of substantially identical construction as described above. The upper and lower pallets are inverted relative to each other so as to be adapted to be stacked in mating relation to pallets of adjacent containers 28. A four-sided rectangular sleeve 48 extends between and is positioned in engagement with the upper and lower pallets. The sleeve 48 has a square cross-sectional configuration corresponding to that of the first sleeve receiving groove 42 of the two pallets and the opposite ends of the sleeve are positioned in such groove 42 so as to prevent the sleeve from shifting laterally with respect to the upper and lower pallets. The container may also include a bottom floor panel 49 of double wall corrugated paper or the like, and a similar cover panel 50, which are sized to be received within the sleeve. Also, the container may be held together by a plurality of strapping bands 35, with the bands being located and retained against lateral movement by the channels 34. 
     When the containers 28 are in stacked condition as shown in FIG. 5, the weight of the upper containers is transmitted from pallet to adjacent inverted pallet to sleeve, and likewise from sleeve to pallet to inverted pallet. Thus, the side walls formed by the sleeve become vertical load bearing members, and the payload within the container carries no significant portion of the vertical load. The interengagement between the sleeve 48 and groove 42 serves to provide dimensional stability to the sleeve and prevents outward bowing of the sidewalls thereof. In addition, the strapping bands 35 tend to resist outward bowing of the sidewalls. 
     In the embodiment of FIGS. 3 and 4, the container 51 comprises two pallets 20 as described above, but includes a sleeve 52 of octagonal outline in cross-section. The sleeve 52 is sized to be received in the second groove 44a, 44b of the two pallets, and it provides improved load bearing strength by reason of its octagonal configuration. Also, the floor and cover panels 53, 54 of the container conform to the outline of the sleeve 52 so as to be received within the confines of the second groove 44. Further, in the specific illustrated embodiment, there is also included a bag 56 within the container for supporting granular or like substances. 
     FIG. 17 schematically illustrates a method of producing shipping containers 28 in accordance with the present invention. As illustrated, there is provided a conveyor having a right-angled turn along its length. Also, a first stack of pallets for forming the bottoms of the containers is positioned adjacent the upstream end of the conveyor, with the pallets disposed in a nested relation with the foot means thereof extending downwardly in the manner shown in FIG. 18. A second stack of nested pallets, and which are of the same construction as the pallets of the first stack, is positioned midway along the conveyor, but with the second stack being oriented with the foot means projecting upwardly in the manner shown in FIG. 19. 
     A suction device 60 is provided adjacent each of the stacks of pallets, for selectively lifting individual pallets from the stacks and depositing the same on the conveyor, or on a sleeve, as the case may be. As illustrated, the suction devices 60 each include four separate suction cups 62, which are disposed to engage each of the four flat areas 38 formed on each side of the pallets. 
     In operation, the pallets forming the bottoms of the containers are sequentially positioned on the upstream end of the conveyor by the suction device 60. A supply of collapsed sleeves 48 is also provided, with each sleeve having a cross-sectional configuration, when opened, corresponding to one of the first and second sleeve receiving grooves of the pallets. In the illustrated embodiment, the sleeves 48 have a square configuration, and conform to the outline of the first groove 42 in the pallets. A selected sleeve is opened and positioned with one end thereof disposed in the first groove 42 of the bottom pallet on the conveyor. The conveyor then transports the bottom pallet and sleeve past the package loading station where a product is placed within the sleeve, and thereafter, the uppermost inverted pallet from the second stack is removed and positioned on top of the sleeve so that the upper end of the sleeve is positioned within the first groove 42 of such pallet. Next, the container moves through a first banding station, and then a second banding station, wherein the upper and lower pallets are interconnected by the bands 35 for maintaining the integrity of the container. The finished container 28 may then be removed from the conveyor by a forklift truck. 
     As will be apparent to those skilled in the art, other means for grasping and lifting the pallet may be employed as an alternative to the illustrated flat ares 38. For example, openings may be formed in the pallet which are adapted to be penetrated by a suitable lifting device other than a suction operated device. 
     In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.