US 3638586 A
A four-way entry pallet of a construction enabling it to be made of molded plastic material to provide lightness without sacrifice of strength, comprises top and bottom walls, two pairs of opposite sidewalls having openings for receiving tines of a lift fork, reinforcing connecting columns between the top and bottom walls, and openings in the top and bottom walls, providing lightness. The top wall comprises T-shaped reinforcing ribs which provide strength and rigidity. Some of the openings in the bottom wall are enlarged to accommodate supporting wheels on tines of a lift fork, and have opposite bevelled edges providing ramps for such wheels; and lower edges of openings in the sidewalls are also bevelled to provide such ramps.
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Description (OCR text may contain errors)
Unite tates Patent Elshout 1 Feb. 1, 1972  PALLET Primary ExaminerBobby R. Gay  Inventor. Anthony E. Elshout, San Francisco, CalIf. Assistant Examiner Glenn o. Finch [731 Assignee: Crown Zellerbach Corporation, San Frau- Attorney-Stanley Bialos, Corwin R. Horton and Robert E.
cisco, Calif. Howard  Filed: June 5, 1970 ABSTRACT 82 [211 NO A four-way entry pallet of a construction enabling it to be made of molded plastic material to provide lightness without  U.S.C| ..l08/58 a rifi e of trength, comprises top and bottom walls, two -565d 19/18 pairs of opposite sidewalls having openings for receiving tines  Field of Search 108/5 1, 58 f a lift f k i f i connecting columns between the top and bottom walls, and openings in the top and bottom walls,  References cued providing lightness. The top wall comprises T-shaped reinforc- UMTED STATES PATENTS ing ribs which provide strength and rigidity. Some of the openings In the bottom wall are enlarged to accommodate 3,307,504 3/1967 Cloyd et al ..l08/5l upporting wheels on tines of a lift fork, and have opposite 2,710,160 6/1955 Bltney ..l08/5l b lled edges providing ramps for such wheels; and lower 11187400 H1964 Kemp, at M10858 edges of openings in the sidewalls are also bevelled to provide 3,187,689 6/1965 Hess v. ....lO8/58 Such ramps, 3,330,228 7/1967 Donnelly ..108/5l 3,424,110 l/l969 Toot JOB/53 5 Claims,9Drawing Figures Q11 4 A 6 I] I I L (I 7 1 I I I [:1 [:l I l H l [:1 El I I l I I I I I L l E] III L 1 I I I I L I I III H :l l '9 i l l l l l l l G I::II II lL II lL IIIM [IV 1 I fi Ffi I I E:
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PATENT ED FEB 1 i972 sumsum" INVENTOR. ANTHONY L. ELSHOUT WE: ATTORNEYS PALLET SUMMARY AND OBJECTS Summarizing the invention hereof, the pallet is rectangular in horizontal shape and is made of relatively light weight plastic material. It comprises top and bottom walls, and two pairs of opposite sidewalls which are integrally connected together. The walls are provided with apertures for lightening the pallet.
Each sidewall has spaced apart openings with the openings in one sidewall aligned with the openings of the opposite sidewall, for receiving lift fork tines which are insertable in either direction; and the upright sides of such openings are flared or slanted inwardly to guide the tines into the pallet without damaging the pallet. Such tine receiving openings in one pair of opposite walls are longer in width than those in the other pair of opposite sidewalls to accommodate tines of different widths. Upright reinforcing columns rigidly connect the top and bottom walls.
Tines of the forks of one well-known type of lift truck which is hand operated, are supported at their front ends on wheels; and to allow the wheels to enter between the top and bottom walls without pushing the pallet, the lower edges of at least some of the tine receiving openings in the sidewalls are bevelled to provide ramps for allowing the wheels to ride readily into the pallet. Also, some of the openings in the bottom wall are enlarged to receive such wheels when the tines are inserted into the pallet; and opposite edges of such openings are bevelled to provide ramps to facilitate riding of the wheels thereover.
From the preceding, it is seen that the invention has as its objects, among others, the provision of an improved pallet ofa construction enabling it to be made of light-weight plastic naterial which can be molded, is of sturdy construction, is provided with special reinforcing ribs to permit such lightweight without sacrifice of strength or rigidity, and which is also provided with bevels along lower edges of openings, which form ramps over which wheels on the lift fork can ride without damaging or pushing the pallet. Other objects of the invention will become apparent from the following more detailed description and accompanying drawings in which:
DESCRIPTION OF FIGURES FIG. 1 is a plan view looking at the top ofthe pallet;
FIG. 2 is a side elevational view looking in the direction of arrow 2 in FIG. 1',
FIG. 3 is a horizontal section taken in a plane indicated by line 3-3 in FIG. 2;
FIG. 4 is a longitudinal vertical section taken in planes indicated byline 4--4 in FIG. 1;
FIG. 5 is a side elevational view looking in the direction of arrow Sin FIG. 1;
FIG. 6 is an enlarged fragmentary vertical section in the same plane as the FIG. 4 section, illustrating how a wheel on a lift fork tine is accommodated by the pallet and rides over bevelled portions forming edges of openings in the pallet;
FIG. 7 is a fragmentary vertical section taken in a plane indicated by lines 7-7 in FIG. 1;
FIG. 8 is an enlarged vertical section illustrating a bevelled edge providing a ramp for a wheel on a lift fork tine, taken in the plane indicated by line 88 in FIG. 3; and
FIG. 9 is an enlarged transverse vertical section of a T- shaped reinforcing rib.
DETAILED DESCRIPTION The pallet is advantageously of plastic material, desirably so called foamed (aerated) high density polyethylene which has an interior cellular structure and a solid exterior skin, and is advantageously molded by well-known injection-molding technique. Although foamed polyethylene is a desirable material because of lightness and strength, other moldable thermoplastic or thermosetting resins may be employed, such as acrylonitrile butadiene-styrene, polystyrene, polypropylene or polyesters.
With particular reference to FIGS. 1 through 4, the pallet is rectangular in horizontal section, comprising top wall 2, bottom wall 3, and a pair of opposite sidewalls 4 which are longer than the other pair of opposite sidewalls 6, thus providing the rectangular shape. The top surface of top wall 2 is planar; and such wall is provided with a plurality of rows of spaced apart openings 7 to lighten the structure, and which are desirably of rectangular shape except the intermediate openings adjacent opposite sidewalls 6, which are trapezoidal in shape for a purpose to be described. These openings form longitudinally extending flat webs 8 therebetween, and also transversely extending flat webs 9. The side edge portions (rim) of top wall 2 are formed of flat webs 11. Thus, strength and at the same time lightness obtains, which are important. Reinforcing flanges 12 are integral with the respective longitudinally and transversely extending webs 8 and 9, but are narrower than 'such webs, thus forming top wall 2 essentially of T-shaped reinforcing ribs 8, l2, and 9, 12. Webs 11 which form the top wall rim, are provided with downwardly extending flanges 13 along the inner edges thereof, thus also providing reinforcement to enhance strength.
With particular reference to FIG. 3, it will be noted that bottom wall 3 is also provided with a plurality of relatively small openings 16, most of which are preferably rectangular in shape, thus serving to lighten the structure. In addition, four large openings 17 which are for the purpose of accommodating wheels on a lift fork tine, are formed adjacent the respective corners of the pallet. Openings 17 also lighten the pallet. The bottom openings leave narrow flat webs 18 extending in a longitudinal direction, and narrow flat webs 19 extending in a transverse direction. Extending in a longitudinal direction midway of larger lift fork wheel accommodating openings 17, are wide flat webs 21 over which the wheels can ride.
Top and bottom walls 2 and 4 are rigidly and integrally joined or connected together by a plurality of upright columns 22 rectangularly shaped in cross section, and by a plurality of columns 23 which are L-shaped in cross section; and L-shaped columns 24, which form part of the sidewalls of the pallet, are provided at the respective corners of the pallet. Also, a trapezoidal, cross-sectionally shaped column 26, connects the top and bottom walls midway of each of the shorter sidewalls 6 and between wheel accommodating openings 17 adjacent such sidewall. The opposite surfaces of each column 26 and an adjacent comer column 24 taper or slant inwardly toward each other to provide guide surfaces 26' for facilitating insertion of a lift fork tine. It is for this reason that each column 26 is trapezoidal in cross-sectional shape.
From the preceding it is seen that the four wheel accommodating openings 17, each adjacent a corner of the pallet, are aligned longitudinally and transversely in parallel rows. For insertion of lift fork tines, the shorter opposite sidewalls 6 are provided with spaced-apart openings 27 adjacent column 26; and narrower openings 28 are provided in each long sidewall 4 for a similar purpose; the lateral edges adjacent such openings being slanted inwardly toward each other as indicated at 30 for guiding such tines. In addition to the tinereceiving openings the sidewalls 4 and 6 are desirably provided with openings 29 which lighten the pallet.
The arrangement of tine receiving openings 27 and 28 in the sidewalls is such that tines of a lift fork may be inserted underneath the top of the pallet from any one of its sides, thus providing a so called four-way entry pallet. In commercial use, there are two well-known types of lift forks, one known as a hand lift fork (hand operated jack mechanism) which has relatively long and wide tines, the front end of each tine being supported on a wheel as is illustrated schematically in FIG. 6. The wider tine receiving openings 27 are for such wheel-supported tines. Another type of lift fork in a power-operated fork which has narrower and shorter tines now mounted on wheels, for which narrower tine-receiving openings 28 are adapted.
Referring particularly to FIG. 6, in which a tine 32 sup' ported at its front end on wheel 33 is shown schematically, in order to prevent the pallet from being pushed by the wheels when the tines are inmrted through side openings 27, the
lower edge of each opening 27 is bevelled (preferably at about a 45 angle but such angle is not critical), to slant upwardly from the bottom, to thus form ramps 34 for allowing the wheels to ride over them without pushing the pallet. When a wheel enters side opening 27 it rides on a wide web 21, and then drops into enlarged wheel accommodating or receiving opening 17 adjacent one side of the pallet. Upon further insertion of the fork, the wheel then rides over the opposite edge of opening 17 onto a wide web 21 and then into the enlarged opening 17 at the opposite side of the pallet, whereupon the pallet can be lifted.
The opposite edges of each of these wheel-accommodating openings 17 in alignment with the opposite side openings 27, are also bevelled in the same direction as ramps 34 to provide ramps 36 for the purpose described, thus facilitating insertion of the wheels, and minimizing damage to the pallet. The ramps 34 and 36 are all as shown in FIG. 8. When a wheel is moved into one wheel-accommodating opening 17 and from that opening toward the opposite opening 17, it is supported by and rides over wide bottom webs 21. 7
Although the wider tine-receiving openings 28 in sides 4 are not primarily intended to receive wheel-supportedtines, their lower edges are desirably bevelled to provide ramps 37 for the purpose of deflecting the end of a tine into the opening should it strike such lower edge, thus minimizing damage to the pallet.
As previously related, the pallet is formed of molded material. Its construction is such that it can be molded in two individual sections in two separate molds; the sections being rigidly bonded together after being molded, either by welding of the material itself or by a strong adhesive, such as an epoxy resin, thus forming an integrally bonded molded structure. The molded sections are an upper section and a lower section, which are bonded together along a plane indicated by the dotted line 38 in FIG. 2, which is in the plane of the section line 3-3 in such FIG.
In the embodiment of the invention illustrated, the pallet has an overall width of about 40 inches, an overall length of about 48 inches, an overall height of about inches, and each wheel-accommodating opening 17 is about 1 l inches long and 9 inches wide. In this connection, FIGS. 1 through 3 are of substantially the same scale, thus the other dimensions can be readily determined from the dimensions given. The pa]- let made from foamed (aerated) high density polyethylene, aerated to a density of about 0.6, weighs about 26 pounds. Although the pallet is desirably of plastic material, it can be made of other material, such as metal, and the features thereof, particularly the ramp construction and the T-shaped top reinforcing ribs will provide the advantages discussed.
1. A pallet comprising an integrally bonded molded structure including a top wall, a bottom wall, two pairs of opposite sidewalls, each of said top and bottom walls having a plurality of spaced openings therein which lighten the structure and which leave flat webs about openings extending between each pair of opposite walls, upright reinforcing columns integrally joined to top and bottom webs to provide a rigid connection between such top and bottom walls, reinforcing flanges integral with and narrower than such top webs and forming therewith T-shaped reinforcing ribs extending between each pair of opposite sidewalls, at least one pair of opposite sidewalls each having spaced-apart openings to receive tines of a lift fork with the openings in each of said opposite walls in alignment with the respective openings in the opposite wall, four of the openings between webs in the bottom wall each adjacent a corner of the pallet being enlarged to accommodate supporting wheels on the tines with a pair of such enlarged openings in alignment with each pair of opposite tine receiving openings, and the flat bottom webs including a web extending substantially between each pair of such enlarged openings upon which said wheels can ride.
2. The pallet of claim 1 wherein opposite edges of each enlarged bottom opening in alignment with a pair of tine-receiving openings are bevelled to provide ramps to allow said wheels to ride thereover.
3. The pallet of claim I wherein said flat bottom webs upon which said wheels can ride are integrally connected to webs extending transversely with respect thereto between opposite sidewalls of the pallet, and said latter opposite sidewalls are provided with aligned tine-receiving openings.
4. The pallet of claim 1 wherein opposite edges of each enlarged bottom opening in alignment with a pair of tine-receiving openings are bevelled to provide ramps to allow said wheels to ride thereover, the lower edge of each tine-receiving opening is bevelled also to provide such ramp, said flat bottom webs upon which said wheels can ride are integrally connected to webs extending transversely with respect thereto between opposite sidewalls of the pallet, said latter opposite sidewalls are provided with aligned tine-receiving openings, and wherein the pallet is formed of plastic material comprising an upper section and a lower section rigidly bonded together.
5. The pallet of claim 1 wherein said flat bottom webs include a pair of spaced-apart webs located between said pairs of opposite tine-receiving openings and which extend between said one pair of opposite sidewalls and also webs extending transversely with respect to said pair of spaced-apart webs, and wherein the webs upon which the tine wheels can ride are wider than the aforementioned spaced apart and transversely extending webs.