US 3112715 A
Description (OCR text may contain errors)
1953 T. P. CALLAHAN ETAL 3,112,715
FOLDABLE EXPENDABLE PALLET Filed June 9. 1961 3 Sheets-Sheet l FRANK J. KUSIAK JR.
THOMAS P. CALLAHAN INVENTORS.
1963 T. P. CALLAHAN ETAL 3,112,715
I FOLDABLE EXPENDABLE PALLET 3 Sheets-Sheet 2 Filed June 9, 1961 m A m FRANK J. KUSIAK JR.
THOMAS P. CALLAHAN INVENTORS.
BY 621%.. We
1963 T. P. CALLAHAN ETAL 3,112,715
FOLDABLE EXPENDABLE PALLET 5 Sheets-Sheet 5 Filed June 9. 1961 FRANK J. KUSIAK JR.
THOMAS P. CALLAHAN INVENTORS.
United States Patent 3,1l2fi'l5 FQLIBA 1E Thomas P. Callahan, Springfield, and m Agar/am, Mass, assignors to Mor pany, St. Louis, Me n n 1 Claim.
ct. ties-s2 This invention relates to a foldable expendable pallet. More particularly, this invention relates to a foldable expendable pmlet which consists of a single sheet of high strength paper adhesively attached and suspended between two substantially parallel semi-cylindrical channels.
This application is a continuation in part of copending application SN. 516,614, filed lune 20, 1955, now abandoned.
Pallets are widely used in the material handling art and are often made of double-face wooden construction. It is recognized that there are three disadvantages inherent in pallets of this construction. A primary disadvantage of wooden pallets is that they are relatively heavy and add materially to the gross load of the shipment, thereby increasing shipping costs. A second shortcoming of wooden pallets is that they are sufficiently costly that they must be reused. The necessity of reusing the pallets entails appreciable freight charges in returning the empty pallets to the original shipper and, in addition, requires the consignee to keep extensive records of the pallets received from and returned to numerous suppliers. The third major disadvantage of wooden pallets is that they are relatively bulky and take up considerable storage space.
Numerous methods of making inexpensive expendable pallets have been proposed. For example, US. atent 2,506,346 illustrates a non-foldable pallet that is prepared from sheets of heavy corrugated boxboard stock and has closed semi-cylindrical channels attached to the top surface thereof. While certain of the expendable pallets heretofore proposed have some merit, all of them are still relatively costly to make. Moreover, the proposed pallets are relatively bulky and thus take up considerable space in storage.
Accordingly, it is an object of this invention to provide a foldable expendable pallet that can be produced at low cost and requires a minimum of space for storage.
This and other objects and advantages of the present invention will be apparent from the following detailed description and the attached drawings, in which:
FIGURE 1 is a partially exploded perspective view of a pallet of this invention;
FIGURE 2 illustrates a plurality of pallets nested together in one manner in which they may be stored;
FIGURE 3 is a partially exploded perspective view of a folded pallet of this invention.
FIGURE 4 illustrates a plurality of pallets in folded nested relationship for a minimum or" storage space.
FIGURES 5 and 6 are views of partially loaded pallets.
In accordance with the present invention, an extremely light weight and low cost pallet is provided as illustrated in the attached drawings. The preferred construction is shown in FIGURE 1, wherein a sheet of high strength paper 1 is adhesively attached to the perimeters of two substantially parallel spaced semi-cylindrical channels 33 and suspended therebetween. The sernicylindrical channels 33 are longitudinal half-sections cut from spirally wound cemented fiberboard tubes. The two end sections 55 of the high strength paper extend beyond the outer edges of the semi-cylindrical channels.
In addition to their light Weight and low cost of manufacture, a major advantage of the pallets of the present invention is that they require a minimum of space for l. atented use. 3, ltl3 storage. The bottoms of the semi-cylindrical channels are open and the pallets can be easily nested for storage as illustrated in FTGURE 2 or folded as shown in F1- URE 3 for stacking as delineated in FIGURE 4. Such nested storage requires a minimum of floor space. It is equally apparent that since the pallets contain no hollow spaces in their construction other than the channels 33 requ red for the insertion of lifting forks, their use permits maximum utilisation of shipping space in the carrier.
W hen bagged materials are to be carried by the pallets, they are loaded so that the weight is carried almost entirely by the semi-cylindrical channels 33. FIGURE 5 illustrates a three-bag tie in which bag 6 is laid lengthwise on one semi-cylindrical channel 3 and bags 8 and it"; are laid at right angles thereto and across the other semi-cylindrical channel 3. The second and subsequent courses of bags are each rotated through 180 with respect to the course immediately below it. When the pallet is loaded in this manner, it is seen that essentially all of the weight is carried on the semi-cylindrical channels 3-3.
FIGURE 6 represents another embodiment of a loaded pellet in which the entire weight is carried by the semicylindrical channels 3-3. Bags 7 and ll are loaded lengthwise on the semi-cylindrical channels 3-3, with bag '7 being positioned at the forward end of the pallet and bag 11 being positioned toward the rear end of th palet. Bags 9 and 13 are laid at right angles to bags 7 and 11 and across the semi-cylindrical channels 3-3. The second and subsequent courses of bags are rotated through with respect to the course immediately below it.
If the pallets of this invention are loaded with bagged fluid-like powdered materials and stored one on the other, the powdered material contained in the top bags of the lower tiers may flow into the cavities of the semicylindrical channels of the pallet immediately above it. Such flowing may tend to reduce the opening intended for the insertion of the forks of the lift truck and may out immediately prior to use of the pallet, since in ordinary commercial practice a supply of adhesive is available at the pallet loading station. However, sealing the cavities of the open semi-cylindrical channels would detract from the unique storing advantage of the present invention.
The materials employed in the manufacture of the pallets of this invention are critical. Since the weight of the fully loaded pallets is carried predominantly by the semi-cylindrical channels, the semi-cylindrical channels must be of sufficient strength to carry the load without collapsing. Preferably, the longitudinal half-sections are constructed of spirally wound cemented fiberboard tubes. In part, the use of longitudinal half-sections of spirally wound cemented fiberboard tubes is dictated by the consideration that the semi-cylindrical channels must have a wall thickness of only 0.1 to 0.5 inch so that the pallets can be easily nested in a minimum of storage space as illustrated in FIGURE 2 or FIGURE 4. No other known material which is available at a suificiently low cost to be used in an expendable pallet has the high strength/weight ratio required in the construction of pallets of this invention.
The web or supporting floor of the pallet must be a sheet of 70l50-pound lcraft paper. It is necessary to use at least 7tl-pound kraft paper to obtain the necessary strength in the pallet. To function properly, the supporting floor of the pallet must be flexible and cleforni slightly When loaded so that the pallet Wil secure! grip the supporting base on which it rests. This frictional grip is necessary so that the forks of the lift can be ren1 ve. easily from the semi-cylindrical channels. The flexibility of the supporting floor of the pallet also perrnits the individual pallets to be folded, as shown in 3, so that the two tine-receiving channels thereof are nested together. Fifty of such folded pallets can be stored in a space 2 ft. X 3 ft. X 4 ft. as illustrated in FEGURE 4. Thus, fifty stored pallets will occupy only 24 cu. ft. of storage space. Furthermore, the flexibility of the supporting floor of the pallet will also permit the lower bags of a fully loaded pallet to tie in or grip the upper layer of bags of the pallet immediately below it so as to form a tightly knit shipping unit that is more resistant to shifting when subjected to sudden starts stops.
in a particular embodiment of the invention, the liraft paper employed as the pallet floor has high wet strength. By high Wet strength it is meant that the paper, when Wet, will retain at least 25% of its dry strength. High Wet strength papers of this type are well-known in the art and are customarily prepared by impregnating the paper with a the nosetting resin such as a melamineforrnaldehycle resin. Sir larly, the spirally Wound cemerited fiberboard tubes from Which the semi-cylindrical channels are cut are fabricated from high Wet strength paper and a water-resistant adhesive is used in cernen the tubes.
An outstanding feature of the pallets of the present invention is that they are particularly adapted to be used with standard fork ift trucks without the necessity of employing special forks. Accordingly, the semi-cylindrical channels of the pallets of this invention Will preferably have internal diameters of 48 inches and the distance between the center lines of the semi-cylindrical channels is preferably set at from 20 to 30 inches.
The pallets of this invention have undergone extensive field tests and Will easily carry gross loads of up to 203 pounds.
The foregoing description is merely illustrative of the invention and it is obvious that many variations can be creon without departing from the spirit and scope invention.
What is clamed is:
A foldable pallet, adapted to occupy a minimum of space when stored, consisting of, in combination, a pair of substantially parallel open channels defined by rigid longituninal semi-cylindrical sections constructed of halfsections of spirally wound cemented fiberboard tubes having a wall thickness of 0.1 to 0.5 inch and a horizontally orientated flexible supporting Web adhesively attached at the bottom surface thereof to the convex outer surfaces of said semi-cylindrical sections, whereby the center lines of said semi-cylindrical sections are positioned below said supporting Web to receive the two tines of a forl-c lift truck Within the open concave undersurface thereof and whereby said hraft paper may be folded over such that the two tine-receiving channels thereof may be nested first together and then with pluralities of similarly folded pallets to occupy a minimum of storage space.
References fiitetl in the file of this patent UNITED STATES PATENTS 2,344,804 Crosby May 21, 1944 2,696,235 Toifolon Dec. 7, 1954 2,693,696 Strong Jan. 4, 1955