IL34334A - A method of making a lightweight pallet - Google Patents

Description

/38/6 34334/2¾ Vpoon Vp natjra tiosm i»»*o ne»» A METHOD OF MAKING A LIGHTWEIGHT PALLET Thisi invention relates to a method for making a lightweight pallet.

'· ' Heretofore» wooden pallets have "been , extensively used for supporting and transports tng loads. These pallets have been heavy and difficult to handle manually and have consumed considerable time* effort and costs in their manufacture· The. resent invention overcomes these difficulties with this type of pallet by providing lightweight structure which is strong, is readily manually handled and can readily cooperate with a lifting device, for example, a fork-lift truck* tip move the loaded pallets where required.

The pallet le molded readily with a one shot method to provide a platform and Integral lege enclosed in a reinforcing layer. The plat orm and legs are formed from expanded resin heads which have their surfaces fused together and which are bonded to the reinforcing layer covering the same. This provides an extremely lightweight structure which can be manually handled readily and which is so arranged as to permit movemen thereof when loaded fcy a fork-lift truck* In oarrying out the novel method of making the platform, a moid formed o a material which will not interfere with R.P. energy is provided wlt¾i cavities to or the legs and platform. The mold is lined with the reinforcing material and filled with expanded heads which have been moistened. The mold is closed and subjected to R.F. energy which causes the moisture about the beads to heat and in turn heat the beads, causing them to soften and the surfaces thereof become fused together. Also, the beads may expand where necessary to completely fill the mold and press against the reinforcing material to be bonded thereto. At the end of the molding cycle, the pallet is cooled and removed from the mold and is ready for use.

The advantages of the present pallet are that it is lightweight and can be readily handled manually, will support the required load, and the legs are so arranged that they will receive the blades of a fork-lift truck so that the pallet and its load can be readily transported.

Another advantage of the present invention resides in the fact that the one shot method of making the pallets is quick and relatively inexpensive.

Other features and advantages of the invention will be apparent from the specification and claims when considered in connection with the accompanying drawings in which: FIGURE 1 shows a perspective view of a pallet of the present invention.

FIGURE 2 shows a bottom view of FIGURE 1 showing the position of the legs.

FIGURE 3 shows a side view of the pallet of FIGURE 1 showing the reinforcing layer in position.

FIGURE 4 is a bottom view of a pallet embodying another form of the invention.

FIGURE 5 is a side view of FIGURE 4 showing the reinforcing layer in position.

FIGURE 6 shows a sectional view of a bottom part of the mold showing the reinforcing layer in position.

FIGURE 7 is a view similar to FIGURE 6 with the beads in position in the cavity and the reinforcing layer being folded thereover.

FIGURE 8 shows a view of the mold in closed position.

FIGURE 9 is a sectional view through the legs of the pallet of FIGURE 1.

FIGURE 10 is a view partly broken away of the layer of reinforcing material for use in forming the pallet of FIGURE 1.

As shown in FIGURES 1 to 3 and 9, the lightweight pallet of the present invention comprises a platform 10, preferably rectangular in shape, having a top 11, bottom 12 and opposed edge surfaces 13 and 14, and a plurality of integral supporting legs 15 depending from the bottom surface to locate the platform above a supporting surface.

Preferably, the platform and legs are formed integrally of expanded polystyrene or the like beads which have their surfaces fused together. The bead density, for example, in the pallet is between 1 and 6 pounds per cubic foot so that a very lightweight pallet results, which can be easily handled manually.

The top and/or bottom and edges of the platform have a reinforcing layer 16 bonded or otherwise adhered to the surfaces thereof. The reinforcing layer also extends along the depending legs to cover them, at least partially as shown in FIGURES 1 and 3, to provide the desired rigidity and maintain the strength of the pallet.

The reinforcing layer comprises paper, cloth, plastic or the like material which also may be laminated with wire or other reinforcing material. The bead contacting surface of the layer is coated with a suitable adhesive or bonding agent to cause it to be firmly secured to the material of the platform and legs.

As shown in FIGURE 2, the pallet has at least four legs. In the illustrated form of the invention it has nine legs arranged in three rows of three legs each so as to form two pairs of parallel channels 18, 19 which cross and provide for four-way reception of the usual blades or forks of a fork-lift truck (not shown) .

In the form of the invention of FIGURES 4 and 5, the supporting legs are formed as at least two transverse legs or runners. In the illustrated form of the invention, it has three runners or solid ribs 25 extending from the bottom surface of the platform to provide a pair of parallel channels 26 adapted to provide two-way reception of the blades or forks of said fork-lift truck. The reinforcing layer 27 in this form of the invention is bonded or adhered to the top 11, bottom 12 and edge 14 of the platform and around the ribs except for the ends thereof as shown in FIGURE 5.

The pallet is threfore very lightweight and can be readily handled manually, is strong enough to support the desired load, and cooperates with the blades of a lifting device, such as a fork-lift truck, to enable the pallets to be moved thereby.

The pallet is made by an unique one shot method which reduces the time and greatly simplifies the operation, and which also reduces the cost without sacrificing the strength.

In carrying out the method, a two-part mold made of a material which will not interfere with dielectric heating, such as glass reinforced polyester, is used. The lower part 30 is shown in FIGURE 6 for the production of the pallet of FIGURE 1. It has spaced leg forming recesses 31 opening into an upper platform forming recess 32.

'' A sheet 16 of reinforcing material forming the reinforcing layer is shown in FIGURE 10. It has a bottom covering portion 34. When making the pallet of FIGURE 1, the portion 34 is provided with a plurality or cross-cuts 35, one for each leg. The outer ends of the cross-cuts are connected by a plui-rality of foldlines 36 as indicated by the short dash lines, thus forming four triangular sections 34a. It has side edge covering portions 37 formed by the foldline 38 and has end edge covering portions 39 formed by the foldlines 40, 41 to which the top covering end portions 42 are secured.

The reinforcing layer is put into the bottom mold part with the portion 34 supported on the bottom surface 31 of the platform forming recess with the side and end edge portions 37, 39 folded up and the end portions 42 folded out. The triangles 34a formed by the cross-cuts are folded into the leg forming recesses as shown in FIGURE 6 partly covering the walls of the recesses 31. With the mold thus prepared, a quantity of partially expanded polystyrene beads 45, which have been moistened with water and a suitable wetting agent, are put into the mold until the cavities in the mold are filled with these beads. The end portions 42 are then folded, as shown in dot and dash lines in FIGURE 7, over the top to cover the beads. The top part 30b of the mold is put in place, as shown in FIGURE 8, and the mold subjected to dielectric heating, for example R.F. energy, for a short period of time sufficient to cause the moisture aground the beads to be heated. This heated moisture will cause Λ the beads to be heated and soften on the surface with the resu that the beads fuse together, and also to expand, if necessary to maintain the mold filled and cause the beads to be pressed against the reinforcing layer 16 to be securely bonded or adhered thereto. The finished pallet is cooled and removed from the mold and has the structure shown in FIGURE 9. By controlling the density of the beads placed in the mold, the compressive strength sufficient to support a desire load can be obtained.

Claims (1)

1. A making a lightweight insufficientOCRQuality