Pallets

Abstract

A pallet of great strength and durability is provided at small cost, which comprises an upper continuous, rigid sheet of plywood, chipboard, plastic or other suitable material, and a lower sheet or set of strips of like material. Identical cylindrical chipboard spacers of substantial diameters and uniform thickness, which are not subject to cracking or splitting, are interposed at regular intervals between the upper and lower sheets. The spacers oppose parallel wooden surfaces to the inner faces of the sheets. Metallic eyelets fit centrally through the respective spacers and through sheet portions in contact with each spacer, the eyelets being outturned at their ends and having the outturned end portions pressed into flush relation with the outer faces of the sheets. The prongs of a forklift can be inserted from either end or from either side of the pallet so that the center of mass of the pallet and any load carried by it may be disposed between the prongs of the forklift.

Description

This invention relates to pallets for use in the shipment and/or storage of merchandise. While there are no limits to the merchandise with which the pallets may be used, conspicuous examples consist of lumber and of heavy bags of material such as grain, cement and fertilizer. It is common practice to create a stack consisting of a succession of pallets, each spaced from the pallet next below it by a definite quantity of merchandise.

Thus each tier contains an amount of merchandise which can be conveniently handled by a forklift, and the quantity of which is known.

There may be as many as six or eight loaded pallets in a stack, the load on each pallette being heavy so that the load on the lowermost pallet may amount to several tons.

It is important, therefore, that each pallet shall have the capability of sustaining a great weight without being strained to the breaking point, without substantial deflection, and with the capability of enduring such punishing service dependably over an extended period.

In order that the prongs of a forklift may be inserted at various levels of a diminishing stack, it is essential that pallets be included at spaced intervals in the stack and that each pallet shall comprise spaced upper and lower sheets or upper sheets and lower strips of sheet material, between which the forklift prongs may be deeply inserted for engagement with the lower face of the upper sheet.

Ideally, the sheet spacers should be of fairly large cross-sectional area, should be circular in shape, and should have parallel upper and lower faces. They should be of a material having high compressive strength, and should be strongly resistant to splintering and splitting under the weight imposed upon them.

The pallets are subjected to severe compressive strain but not to any very great tensile strain. It is essential, however, that the upper sheet and lower strips (or upper and lower sheets) of a pallet be joined to one another and to the interposed spacers by suitable tie members, and it is important that the tie members be countersunk in the outer layers of the sheets and/or strips so that nothing protrudes which might damage the merchandise with which the pallets are used.

The business of supplying pallets of the kind referred to is a highly competitive business. It is very important, therefore, that pallets be furnished having the requisite capabilities at minimum cost of materials and labor.

To this end, it is a feature that the spacers are made up of layers of chipboard which have no tendency to chip or crack, which have high compressive strength, and which can be produced at a very moderate cost. The spacers may be identical in material and structure with plugs which are commonly used in the ends of rolls of paper during the shipment of such rolls, and since even reject plugs have been found useful as pallet spacers, the production of pallets can most economically and advantageously be carried on concurrently with the manufacture of paper roll plugs.

The means for connecting the pallet sheets and intervening spacers to one another may advantageously consist of thin-walled metallic eyelets, preferably initially flanged at one end and adapted to be flanged at the opposite end under pressure and to be countersunk by pressure at opposite ends into the outer portions of the pallet sheets.

Other objects and advantages will hereinafter appear.

In the drawing forming part of this specification,

FIG. 1 is a perspective view of a practical and advantageous pallet embodying features of the invention; and

FIG. 2 is a fragmentary view in sectional elevation of the structure of FIG. 1, showing a typical assembly of the upper sheet, a lower strip, a single spacer and a single eyelet in assembled and fixed relation to one another.

As shown in the drawing the illustrative pallet 10 comprises an upper sheet 12 which may be a rigid sheet of plywood, chipboard, plastic, or a combination of them. Three parallel, coplanar, equally spaced lower strips 14 of like composition run longitudinally of the pallet 10, the strips 14 being uniformly and identically spaced from the sheet 12 by identical spacer blocks 16. As shown on an exaggerated scale in FIG. 2, the upper and lower faces of the pallet may have a thin coating of plastic applied. This feature is optional, but it can be very important where frictional rubbing of material holding bags or boxes against the pallet surfaces can be damaging to the bags or boxes. Each spacer block 16 is shown as consisting of two chipboard discs 18, although the number could be varied according to the thickness of the discs and the spacing desired. Each spacer block is circular in horizontal section, is formed with a central bore, and is composed of chipboard, a board made up of wood chips united by a suitable, strong, bonding resin. The fact that chipboard is used for this purpose is a salient feature of the invention. Chipboard is a solid and strong material having no uniform grain. It is not subject to splitting or cracking.

It also has the very great advantage that the blocks 16 are identical in composition and structure with chipboard plugs which are provided for insertion in opposite ends of paper rolls for protecting the rolls during shipment. Such plugs are made in several diameters (31/4, 41/4, and 51/4 inches), each of which can be used with advantage as pallet spacers, depending upon the size of the pallet and the ruggedness required for the service which the pallet will be required to perform.

In point of fact, paper roll plugs are more critical as to structure than pallet spacers, and rejected paper roll plugs can be, and are, used as pallet spacers, so that these essential pallet parts can be had at virtually no expense if the manufacture of paper roll plugs and the manufacture of pallets are conducted concurrently. If plug rejects are not produced in sufficient volume to satisfy pallet requirements, first class plugs can be utilized in pallet manufacture, but the total outlay for spacers is greatly reduced by the utilization of plug rejects.

Each spacer 16 is provided with a central bore 20 of appropriate diameter to receive and fit a thin-walled eyelet 22 of comparatively small diameter. Bores of the same diameter are provided at appropriate, registering points in the sheet 12 and in the strips 14.

The eyelets may be initially straight at both ends, or they may be flanged at one end. In either case the eyelet is long enough to provide uninterrupted flanges at its opposite ends when subjected to deforming pressure. By causing the eyelet setting members to approach one another to a predetermined limit in which they are spaced apart by exactly the thickness of the pallet, the eyelet can be caused to become flanged at both ends with the flanges 24 countersunk by pressure to lie flush with the outer faces of the pallet.

We have described what we believe to be the best embodiments of our invention. What we desire to secure by letters patent is set forth in the appended claims.

Claims

We claim:

1. A pallet for use in the shipment and storage of merchandise comprising, in combination,

a. upper and lower layers of sheeted material which is strongly resistant to bending both longitudinally and transversely,

b. compression members in the form of circular spacers of substantial diameter and thickness interposed between said upper and lower layers, the spacers being composed of chip-board which is strongly resistant to cracking and splitting under pressure and which has high compressive strength, and

c. tension members in the form of thin-walled metallic eyelets of comparatively small, uniform external diameter, each of which extends snugly through and fits within bores formed in the upper and lower layers of sheeted material and also extends centrally, snugly through, and fits within, an interposed spacer, each eyelet being continuously flanged at its ends and having its flanges countersunk by pressure into the outer faces of the upper and lower sheeted material, the spacers being separated substantially from one another both longitudinally and laterally of the pallet so that the prongs of a forklift can be inserted from either side or either end of the pallet.

2. A pallet as set forth in claim 1 in which the upper and lower layers consist of woody material and in which the outer faces of the pallet have plastic coated surfaces for the protection of stacked material.