PALLET FORMED FROM INTERLOCKING MEMBERS

Abstract: The pallet comprises a pair of elongate bearers (3) and an upper deck and a lower deck of slats (5a, 5b) supported by the bearers (3). Each bearer (3) is generally trapezoidal in transverse section and comprises upper and lower walls and inner and outer side walls (11a, 11b). Each bearer (3) further comprises upper and lower openings (9a, 9b) which receive end sections of the slats (5a, 5b). The slats (5a, 5b) are retained securely by the bearers (3) without nails or other fasteners being required by interlocking end sections of the slats (5a, 5b) and the bearers (3).

Description: PALLETFORMEDFROMINTERLOCKINGMEMBERS The present invention relates to a pallet. In particular, the present invention relates to a pallet of the type described in Australian patent 642,474 of Bruce Alexander McPhee (hereinafter referred to as "the HcPhee pallet") which is constructed from steel bearers and wood planks or slats (hereinafter referred to as "slats"), without nails or other conventional fasteners. An object of the present invention is to provide a pallet which is an improvement of the McPhee pallet. According to the one aspect of the present invention there is provided a pallet comprising, a pair of elongate bearers, an upper deck and a lower deck supported by the bearers, each bearer having upper and lower openings which receive the end sections of the decks, and an outward facing surface of each deck being spaced above or below the bearers so that the outward facing surfaces of the decks and not the bearers contact adjacent pallets when a plurality of pallets are stacked one on top of the other. It is preferred that each bearer comprise upper and lower walls and inner and outer side walls. According to another aspect of the present invention there is provided a pallet comprising, a pair of elongate bearers, an upper deck and a lower deck supported by the bearers, each bearer having upper and lower walls and inner and outer side walls, each bearer having upper and lower openings which receive the end sections of the decks, and the upper and/or lower walls of each bearer tapering from the outer side wall to the inner side wall. It is preferred that the included angle α between the inner side wall and one or both of the tapered upper wall and the tapered lower wall be greater than 90°. It is preferred particularly that the included angle be greater than 95°. It is preferred more particularly that each bearer be trapezoidal in transverse section. According to another aspect of the present invention there is provided a pallet comprising, a pair of elongate bearers, an upper deck and a lower deck supported by the bearers, each bearer having upper and lower walls and inner and outer side walls which are fitted together without welding, riveting or fasteners and thereafter are hot-dip galvanised to hold the walls together, and each bearer having upper and lower openings which receive the end sections of the decks. It is preferred that the upper and lower walls and inner and outer side walls be fitted together by interference fit or by snap lock assemblies. It is preferred particularly that the upper and lower walls each comprise a plurality of spaced apart pressed wall sections. It is preferred more particularly that the inner and outer side walls be roll-formed. It is preferred that the end sections of the decks and the bearers be formed so that the decks are retained securely by the bearers without nails or other fasteners being required to hold the decks in position. In one arrangement, it is preferred that the upper and lower decks comprise a plurality of slats. It is preferred that the slats be retained securely by the bearers without nails or other fasteners being required by interlocking the end sections of the slats and the bearers. It is preferred particularly that the slats and the bearers be interlocked by positioning each end section of each slat so that a reaction surface reacts against the outer side wall of the bearer in which the end section is received and so that a groove in the inwardly facing surface of each end section of each slat engages the inner side wall of the bearer in which the end section is received. It is preferred that it be necessary to bow each end section to interlock the end sections with the bearers. It is preferred particularly that the distance between the reaction surface and the groove of each end section of each slat be greater than the distance between the reaction surface of the outer side wall and the inner side wall of the bearers so that it is necessary to bow each end section to interlock the end sections with the bearers. In an alternative arrangement it is preferred that the upper and lower decks be formed from a profiled steel sheeting. It is preferred that the bearers be formed from steel. It is preferred that the slats be formed from wood. The present invention is described hereinafter by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of a section of one preferred embodiment of a pallet in accordance with the present invention with a number of slats removed for clarity; Figure 2 is an end view of the pallet in the direction of the arrow A in Figure 1; Figure 3 is a perspective view of an end section of one of the upper slats shown in Figures 1 and 2; Figure 4 is a perspective view of the section of the pallet shown in Figure 1 from below the pallet with the lower array of slats removed for clarity and the upper array of slats shown in a position immediately prior to insertion of the slats into the bearer shown in the figure; Figure 5 is a perspective view of another preferred embodiment of a pallet in accordance with the present invention which differs from the embodiment shown in Figures 1 to 4 in the construction of the bearers; Figure 6 is an exploded perspective view of the pallet shown in Figure 5 which illustrates general detail of the components of the pallet; Figure 7 is a perspective view illustrating the component parts of a bearer of the pallet shown in Figures 5 and 6; and Figure 8 is a perspective view of an upper wall element of the bearer of the pallet shown in Figures 5 to 7. The preferred embodiment of the pallet shown in Figures 1 to 4 comprises a pair of parallel spaced-apart elongate steel bearers 3 (only one of which is shown in the figures), an upper array of wood slats 5a, and a lower array of wood slats 5b. As can best be seen in Figures 1 and 4, each bearer 3 comprises upper rectangular openings 9a and lower rectangular openings 9b and the end section of each slat 5a, 5b is received in the associated openings 9a, 9b. As is described hereinafter in detail, the slats 5a, 5b and the bearers 3 are constructed so that the slats 5a, 5b are retained securely by the bearers 3 without nails or other fasteners being required to hold the slats 5a, 5b in position. In the embodiment shown in Figures 1 to 4, each bearer 3 is formed by folding a flat sheet of steel which has cut-out sections that are positioned to form the openings 9a, 9b in the bearer 3. With particular reference to Figure 2, in accordance with one feature of the present invention, each bearer 3 comprises inner and outer side walls 11a, lib and upper and lower walls 13a, 13b which taper from the outer side wall lib towards the inner side wall 11a so that the bearers 3 are generally trapezoidal in transverse section. The openings 9a, 9b are formed in the tapered upper and lower walls 13a, 13b. The tapering of the upper and lower walls 13a, 13b means that the included angle α (Figure 2) between the inner side wall 11a and the tapered upper and lower walls 13a, 13b is greater than 90°, which is the conventional angle for bearers. The applicant has found that the 90° angle of the conventional bearers forms sharp corners which dig into the soft fleshy parts of the hands of persons when the persons insert their hands between adjacent slats to grip the bearers and lift the conventional pallets. The applicant has found that the tapering of the upper and lower side walls 13a, 13b so that the included angle α is greater than 90° significantly alleviates this problem. This is a particularly important feature from the viewpoint of occupational health and safety considerations. In addition, the applicant has found that tapering the upper and lower side walls 13a, 13b reduces the amount of material required, and therefore the weight, of the bearers 3. In addition, the applicant has found that the trapezoidal section bearers 3 have improved stiffness when compared with conventional square section bearers. In accordance with another feature of the present invention, after folding the sheet steel to form the bearers 3, the bearers are hot-dip galvanised. It has been found surprisingly by the applicant that the coating formed by this process is sufficiently strong to hold together the bearers 3 and that, as a consequence, rivets, spot welding, and other conventional means of retaining the shape of the folded steel sheet are not required. This is an important feature from the viewpoint of minimising manufacturing costs. With particular reference to Figure 3, in accordance with another feature of the present invention, as is described in more detail hereinafter, each slat 5a, 5b is formed so that the outwardly facing surfaces 41 of the slats 5a, 5b extend above or below the upper and lower walls 13a, 13b of the bearers 3. The arrangement increases frictional contact between the pallet and an underlying surface, when compared with the contact surface area of the HcPhee pallet. The increased contact surface area is important from the viewpoint of occupational health and safety considerations. In accordance with another feature of the present invention the slats 5a, 5b are securely retained by the bearers 3 without the necessity to use nails or other fasteners. This is achieved in the preferred embodiment shown in Figures 1 to 4 by forming the slats 5a, 5b and the bearers 3 so that these components interlock. It is noted that it is a significant benefit in terms of minimising manufacturing costs to be able to provide a pallet which does not require nails or other fasteners to hold together the slats and the bearers. In addition, such a pallet avoids damage to products being transported which is often caused by nails and other fasteners used in conventional pallets. In this connection, with reference to Figures 2 and 4, each end section of the slats 5a, 5b comprises a tongue 23. The tongue 23 is formed by a downward step 21 in the outwardly facing surface 41 at each end section of the slats 5a, 5b, with the downward step 21 having an upright shoulder 29. The above arrangement allows the tongue 23 to extend through the openings 9a, 9b inwardly of narrow wall sections 27 of the upper or lower walls 13a, 13b that are adjacent the outer side walls lib of the bearers 3. Specifically, when a slat 5a, 5b is positioned correctly: (i) the shoulder 29 of the step 21 contacts the edge 28 of the narrow wall section 27, and/or; (ii) the end 49 of the tongue 23 contacts the inner surface of the outer side wall lib and/or; (iii) the outwardly facing surface 41a of the tongue 23 contacts the inner surface of the narrow wall section 27. It is noted that the height of the shoulder 29 determines in large part the extent to which the outwardly facing surfaces 41 of the slats 5a, 5b extend above or below the lower walls 13a, 13b of the bearers 3. Furthermore, with reference to Figures 3 and 4, the inward facing surface 43 of each end section of the slats 5a, 5b includes a groove 25 which is adapted to be positioned to receive the upper or lower ends 51 of the inner side wall 11a that are adjacent to and in part form the openings 9a, 9b. It can readily be appreciated that, with appropriate selection of the dimensions of the slats 5a, 5b and the bearers 3, the groove 25 and the tongue 23/shoulder 29 at each end of each slat 5a, 5b co-operate with the associated bearer 3 to securely interlock the slats 5a, 5b and the bearers 3 without the necessity to use nails or other fasteners. The distance D t (Figure 3) between the grooves 25 and the shoulders 29 of each slat 5a, 5b, is greater than the distance D 2 (Figure 4) between the upper or lower ends 51 of the inner side wall 11a and the edges 28 of the narrow wall sections 27 of the bearers 3. As a consequence, in order to interlock a slat 5a, 5b and the bearers 3 it is necessary to bow the end sections of the slat 5a, 5b. The effect of bowing the end sections of the slats 5a, 5b is to make it very difficult to disconnect the slats 5a, 5b from the bearers 3. The preferred embodiment of the pallet shown in Figures 5 to 8 is similar in many respects to the

Claims: embodiment shown in Figures 1 to 4. The main difference between the two embodiments is the construction of the bearers 3. With reference to Figures 5 to 8, each bearer 3 is formed from a number of separate components which are held together initially by interference fit or snap-lock assemblies (or any other suitable means other than welding, riveting or conventional fasteners) and thereafter are hot- dip galvanised to form a strong assembly. With further reference to Figures 5 and 6, the components comprise, separate inner and outer roll-formed side walls 11a, lib and upper and lower pressed wall sections 63. The components also comprise pressed end wall panels 79 which close the ends of the bearers 3. With reference to Figures 7 and 8, the side walls 11a, lib terminate in elongate outwardly opening channels 67. The inner faces 68 of the channels 67 include drilled holes 73 at spaced intervals. The channels 67 and the drilled holes 73 form part of a snap-lock assembly to hold together the side walls 11a, lib and the wall sections 63. The outer side wall lib also includes upper and lower flanges 65 which extend inwardly at right angles to the plane of the outer side wall lib. The upper and lower wall sections 63 are generally rectangular and comprise flanges 69 at opposite ends. The flanges 69 include projections 71 which are adapted to cooperate with the holes 73 in the channels 67 of the side walls 11a, lib. The flanges 69 and the projections 71 also form part of the snap-lock assembly to hold together the side walls 11a, lib and the wall sections 63 . In order to assemble the bearer 3 shown in Figures 5 to 8, the flanges 69 of the upper and lower wall sections 63 are inserted into the channels 67 of the side walls 11a, lib so that the projections 71 on the flanges 69 extend into and are retained in the holes 73 in the channels 67. Thereafter, the end panels 79 are fitted onto the ends of the assembly of the side walls 11a, lib and the upper and lower wall sections 63. The final step comprises hot-dip galvanising the assembled bearer 3. As indicated above, it has been found surprisingly by the applicant that the coating formed provides sufficient strength and that as a consequence welding, riveting, or fasteners are not required. With further reference to Figures 5 and 6, each bearer 3 further comprises a pair of cut-outs 81 which allow the pallet to lock into a pallet racking system. Furthermore, each bearer 3 comprises strengthening ribs 83, shown by way of example in Figure 5 in the inner side wall 11a, to increase the load carrying capacity of the pallet. This is a particularly useful feature when the pallet is used in a racking situation. Many modifications may be made to the preferred embodiment of the pallet of the present invention described above without departing from the spirit and scope of the present invention. By way of example, whilst the preferred embodiment comprises bearers 3 formed from steel and slats 5a, 5b formed from wood, it can readily be appreciated that the present invention is not so limited and the bearers and slats may be formed from any suitable material. CLAIMS : 1. A pallet comprising, a pair of elongate bearers, an upper deck and a lower deck supported by the bearers, each bearer having upper and lower openings which receive the end sections of the decks, and an outward facing surface of each deck being spaced above or below the bearers so that the outward facing surfaces of the decks and not the bearers contact adjacent pallets when a plurality of pallets are stacked one on top of the other. 2. The pallet defined in claim 1 wherein each bearer comprises upper and lower walls and inner and outer side walls. 3. A pallet comprising, a pair of elongate bearers, an upper deck and a lower deck supported by the bearers, each bearer having upper and lower walls and inner and outer side walls, each bearer having upper and lower openings which receive the end sections of the decks, and the upper and/or lower walls of each bearer tapering from the outer side wall to the inner side wall. 4. The pallet defined in claim 3 wherein the included angle α between the inner side wall and one or both of the tapered upper wall and the tapered lower wall is greater than 90°. 5. The pallet defined in claim 4 wherein the included angle α is greater than 95°. 6. The pallet defined in any one of claims 3 to 5 wherein each bearer is trapezoidal in transverse section. 7. A pallet comprising, a pair of elongate bearers, an upper deck and a lower deck supported by the bearers, each bearer having upper and lower walls and inner and outer side walls which are fitted together without welding, riveting or fasteners and thereafter are hot-dip galvanised to hold the walls together, and each bearer having upper and lower openings which receive the end sections of the decks. 8. The pallet defined in any one of claims 2 to 7 wherein the upper and lower walls and inner and outer side walls are fitted together by interference fit or by snap lock assemblies. 9. The pallet defined in any one of claims 2 to 8 wherein the upper and lower walls each comprise a plurality of spaced apart pressed wall sections. 10. The pallet defined in any one of claims 2 to 9 wherein the inner and outer side walls are roll- formed. 11. The pallet defined in any one of the preceding claims wherein the end sections of the decks and the bearers are formed so that the decks are retained securely by the bearers without nails or other fasteners being required to hold the decks in position. 12. The pallet defined in claim 11 wherein the upper and lower decks comprise a plurality of slats. 13. The pallet defined in claim 12 wherein the slats are securely retained by the bearers without nails or other fasteners being required by interlocking the end sections of the slats and the bearers. 14. The pallet defined in claim 13 wherein the slats and the bearers are interlocked by positioning each end section of each slat so that a reaction surface reacts against the outer side wall of the bearer in which the end section is received and so that a groove in the inwardly facing surface of each end section of each slat engages the inner side walls of the bearer in which the end section is received. 15. The pallet defined in claim 13 or claim 14 wherein it is necessary to bow each end section of each slat to interlock the end sections with the bearers. 16. The pallet defined in claim 11 wherein the upper and lower decks are formed from a profiled steel sheeting. 17. A pallet comprising, a pair of elongate bearers, an upper deck and a lower deck of slats supported by the bearers, each bearer having upper and lower walls and inner and outer side walls, each bearer having upper and lower openings which receive end sections of the slats, and the slats being retained securely by the bearers without nails or other fasteners being required by interlocking end sections of the slats and the bearers. 18. The pallet defined in claim 17 wherein the slats and the bearers are interlocked by positioning each end section of each slat so that a reaction surface reacts against the outer side wall of the bearer in which the end section is received and so that a groove in the inwardly facing surface of each end section of each slat engages the inner side walls of the bearer in which the end section is received. 19. The pallet defined in claim 16 or claim 17 wherein it is necessary to bow each end section of each slat to interlock the end sections with the bearers.

Inventors: MCPHEE BRUCE ALEXANDER, STEVENS ROGER MILTON, MCPHEE, BRUCE, ALEXANDER, STEVENS, ROGER, MILTON
Applicants: BHP STEEL JLA PTY LTD, MCPHEE BRUCE ALEXANDER, STEVENS ROGER MILTON, BHP STEEL (JLA) PTY. LTD., MCPHEE, BRUCE, ALEXANDER, STEVENS, ROGER, MILTON
Application year: 1995
Main classification: B65D19
IPC codes: B65D19