US 3327882 A
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Description (OCR text may contain errors)
June 27, 1967 R. F. ANDREWS 3,327,882
SHIPPING CONTAINERS Fil y 27, 1954 2 Sheets-Sheet l INVENTOR. 24 205527 E fiwoeina Arrow iv:
June 27, 1967 ANDREWS I 3,327,882
SHIPPING CONTAINERS Filed May 27, 1964 I 2 sheets sheet 2 FIG-4 16 a Fl 6 a? I III II v I? E: igg gmgiwj V a 0 MM; BY a I G 5 fad/ 47'7'0i/Vi)? United States Patent 3,327,882 SIHPPING CONTAINERS Robert F. Andrews, San Jose, Calif, assignor, by rnesne assignments, to Ureseal Corporation, Santa Clara, Calif., a corporation of California Filed May 27, 1964, Ser. No. 370,486 6 Claims. (Cl. 220-4) This invention relates generally to containers, and is more particularly directed to knock-down shipping containers of light weight thermally insulating material.
Many commodities are shipped in containers from their point of origin to a point of destination. For example, fruit and other produce are typically packed in boxes or equivalent containers at the orchard or field and shipped to a cannery or other destination point. In some instances, a number of these containers are placed in larger so-called cargo containers in order to minimize handling during shipment. Similarly, cans and other products are packed in shipping containers at a cannery or factory for shipment individually, or collectively in larger cargo containers, to various destination points. Conventionally, the containers employed under the foregoing circumstances are re-usable. After their contents are unpacked at the destination point, the empty containers are usually shipped back to their point of origin. In this regard, most reusable shipping containers in current use are of the permanently assembly variety and, consequently, occupy as much storage space empty, as they do loaded. As a result, the cost of shipping empty shipping containers to their point of origin is substantially as much as the cost of shipping packed containers to their point of destination. The foregoing is particularly true in the case of maritime shipping. Advantages are, of course to be gained by the provision of shipping containers which may be readily disassembled, i.e., knock-down containers. Return shipment of these containers in disassembled condition may, thus, be accomplished with a material saving in storage space and, therefore, in shipping cost.
Accordingly, it is a primary object of the present invention to provide knock-down shipping containers which are strong and durable in assembled condition, but which yet may be readily disassembled.
Another object of the invention is the provision of a shipping container comprised of interlockable side, top and bottom panels which may be strapped together in a rigid assembly.
Still another and very important object of the invention is to provide a shipping container of the class described which is fabricated of foamed plastic material, such container being, therefore, relatively light in weight and possessing high thermal insulating properties.
It is yet another object of the invention to provide a shipping container formed of foamed plastic panels having complementary interlocking portions arranged to engage each other in a wedge fit.
One other object of the invention is the provision of a shipping container of the class described wherein the foamed plastic panels having tough skins at the surfaces thereof to resist scufiing and penetration by handling implements.
It is a further object of the invention to provide shipping containers of the class described which are relatively simple and economical in construction.
Other objects and advantages of the invention will become apparent upon consideration of the following detailed description in conjunction with the accompanying drawing, wherein:
FIGURE 1 is an exploded perspective view of a shipping container in accordance with the present invention;
FIGURE 2 is a perspective view of an alternate embodiment of a side wall of a shipping container in accordance with the invention;
FIGURE 3 is a perspective view of an assembled shipping container utilizing the structure of FIGURE 2, and illustrating an alternative embodiment with removable skids;
FIGURE 4 is a sectional view taken in the plane 4-4 of FIGURE 3; and
FIGURE 5 is a sectional view taken in the plane 5-5 of FIGURE 3.
Referring now to the drawing, FIGURE 1 in particular, there will be seen to be provided a shipping container 11, formed of interlocking side, top and bottom panels 12, 13, and 14 of foamed plastic material. The side panels 12 are identical to each other and each is of substantially rectangular configuration with complementary interlocking means 16 and 17 provided at its opposite ends. Although the interlocking means may be of a variety of specific forms, the interlocking means 16 preferably comprises a pair of vertically extending longitudinally projecting ribs or tongues 18 and 19 at one end, while the interlocking means 17 preferably comprises a complementary pair of vertically extending grooves 21 and 22 formed in one side face of the panel adjacent its opposite end. The sides of the tongues 18 and 19 are advantageously bevelled as are the sides of the grooves 21 and 22, so as to facilitate a Wedge fit therebetween. In addition, tongue 18 and groove 21 are best of a greater width than tongue 19 and groove 22. With the tongues 18 and 19 of the respective panels engaging the grooves 21 and 22 of adjacent panels, it will be appreciated that the panels define a rectangular marginal side wall.
In order to conserve material, the side panels 12 are preferably formed with longitudinally elongated rectangular air spaces 23 extending vertically therethrough. The air spaces also facilitate interlocking engagement of the side panels with the top and bottom panels 12 and 13 in a manner which is subsequently described in detail. Inasmuch as air is a relatively good thermal insulator and the foam plastic from which the side panels are constructed is an extremely good thermal insulator, it will be appreciated that the side panels, with air spaces included, possess very substantial thermal insulating properties.
The top and bottom panels 13 and 14 are substantially similar to each other and are of generally rectangular configuration. The bottom panel differs from the top panel in that the former is preferably provided with skids 24 which depend from the lower face thereof. The top and bottom panels are respectively provided with central rectangular bosses 26, which respectively project from the lower and upper faces thereof. The bosses are dimensioned to substantially correspond to the inner periphery of the rectangular side wall defined by the panels 12, while the outer periphery of the top and bottom panels is dimensioned to substantially correspond to the outer periphery of the side wall. Consequently, when the top and bottom panels are positioned at the opposite ends of the r, it
side wall, the bosses 26 are engaged with the interior of the side wall and the marginal edges of the top and bottom panels are flush with the exterior face of the side wall. Preferably, the side edges of the bosses are inwardly bevelled, as shown, so as to engage the side wall interior with a wedge fit. The top and bottom panels are further provided with pluralities of rectangular lugs 27 projecting from the lower and upper faces of these panels, respectively. The lugs are positioned centrally adjacent the side edges of the panels intermediate such side edges and the peripheries of the bosses. The width of the lugs is substantially equal to the width of the air spaces 25 of the side panels, so as to snugly engage same when the top and bottom panels are disposed in closing relation to the opposite ends of the side wall. The side edges of the lugs are preferably bevelled, as shown, with the inner side edges thereof being thereby bevelled in opposition to the side edges of the bosses. The lugs, thus, engage the air spaces in a wedge fit, and moreover, it is to be noted that the intervening portions of the side panels between the air spaces and interior faces thereof are clamped in a Wedge fit between the lugs and bosses.
Although the interfitting side, top and bottom panels 12, 13, and 14 form a relatively sturdy container structure, it is preferable that the container include selectively operable fastening means arranged to secure the panels in a rigid unyielding structure capable of withstanding rough handling during shipment. Such fastening means may be provided in a variety of ways, however, same preferably comprise a pair of straps 28 secured to one end of the bottom panel 14 in transversely spaced relation and adapted to be secured to double rings 29, or the like, provided at the opposite end of the bottom panel in corresponding transversely spaced relation. Thus, the straps may be led from the bottom panel upwardly along the adjacent side panel, over the top panel, and downwardly along the opposite side panel to be cinched tight and secured to the rings 29. The interlocking side, top, and botom panels are thereby strapped together to provide a rigid unyielding shipping container. The straps 28 are preferably of Webbing, tape, or equivalent strong, soft material such that the straps will not penetrate into the foamed plastic panels upon being cinched tight therea-bout.
There has been described above a single preferred embodiment of the present invention; however, numerous variations in physical structure are possible, in accordance with this invention. There are illustrated in FIGURES 2-5 certain structural alternatives which, for many applications, are advantageous over the ones illustrated and described above.
Referring first to FIGURE 2, there will be seen to be shown a single side wall of a container in accordance with this invention, and which is identical to three other side walls which, in combination, form a a closed square adapted to receive top and bottom members for completion of a container. The wall 51 of FIGURE 2 is formed of spaced outer and inner panels 52 and 53, respectively, interconnected by integral transverse wall portions 54. This structure then defines a double wall having vertical air spaces 56 between the inner and outer portions thereof. Provision is made for interlocking of the walls with both top and bottom members of the container in grooved relationship. To this end, the outer panel 52 has a raised rib 57 extending longitudinally thereof inward from the outer edge, and the inner panel 53 extends upwardly to the same height as this rib 57. The intermediate wall portions 54 do not extend as high as the inner panel or outer panel rib, and thus define a slot between the last-mentioned members.
Interlocking of the Walls is accomplished in the same manner in this embodiment as described above in connection with FIGURE 1. Thus, at one end of the wall there is formed a pair of vertical ribs 61 and 62 defining therebetween a vertical groove 63. The rib 61 actually comprises an extension of the outer wall panel 52, exclusive of the longitudinal rib 57 atop same. The rib 62 is inset from the inner side of the wall, and is formed as a part of the intermediate wall portion 54, so that a half groove 64 occurs along the edge of the inner wall panel 53.
The opposite end of the wall 51 is square and interlocking means are formed along the inner wall side adjacent this end. A vertical rib 66 is formed in line with the longitudinal rib 57 atop the outer wall panel 52 and a groove 67 is formed vertically of the wall side through the inner wall panel 53, as illustrated.
In this embodiment of the invention the top and bottom panels of the container may be identical. In the event that skids are desired to be employed with the container, same may be removably attached to the bottom of the container as by means of lugs atop the skids fitting tightly into slots 68 formed on the outer surface of the bottom or top panel. Also in this embodiment, as illustrated in FIGURE 3, straps 71 and 72 are shown to be wrapped around the container from adjacent sides so as to crisscross and thereby provide an even greater security of container closure. Removable skids are apertured to accommodate strap passage therethrough and, locking blocks (not shown) may be inserted in the slots 68 to firmly stack the containers with the skids removed.
In the interest of conserving material in the construction of the container hereof, it is desirable to provide air spaces in the elements thereof, such as are provided, for example, in the side walls described. In like manner, the top and bottom elements 73 may be provided with transverse openings 74-, as illustrated in FIGURE 4. In assembly of this container, the side walls are joined together in the same manner as described in connection with FIG- URE 1. It will be seen that the vertical ribs 61 and 62 fit tightly int-o the recessed portions of the adjacent wall and the vertical rib 66 within the slot 63 in the contiguous wall. Here again, advantage lies in the utilization of Wedge fits, as described above. The top of the container is formed wit-h a pair of parallel slots 76 and 77 extending about the periphery thereof on the underside of the top. The top then fits snugly onto the assembled side walls with the longitudinal rib 57 within the top slot 76 and the inner wall portion 53 within the :slot 77. This double interlocking of side walls with top and bottom portions provides a maximized degree of thermal insulation for the interior of the container. It has been found possible with this described construction to maintain the interior of the container at a temperature below the freezing point of water for an almost indefinite period of time. The thermal insulating properties of this container are extremely great, and it is not necessary to utilize refrigerating means in order to employ containers hereof for the shipping of materials at very low temperatures. It is only necessary to initially reduce the interior temperature and then to place goods, such as frozen foods, or the like, within the container and close the container. The degree of heat transfer to the interior of the container is almost negligible, and, consequently, very material saving in transportation costs is realizable with the present invention.
Considering now the various panels of the container in greater detail as to materials from which they may be constructed, it is to be noted that a variety of foamed plastic materials are suitable for this purpose. For example, foamed polyurethane plastic, foamed polystyrene plastic, and equivalent foamed plastic materials may be advantageously employed in the construction of the side, top, and bottom panels of the shipping container. In this regard, a foamed polyurethane plastic comprised of a mixture of a polyether prepolymer designated EP 8680 AP and a resin-catalyst combination designated as EP 8664 BF, both as manufactured by Archer Daniels Midland Co. of Minneapolis, Minn. has been found particularly well suited to this purpose. By varying the relative proportions of the two constituents, the density of the resulting foamed plastic material may be readily varied as desired. Irrespective of the specific manner of providing a desired density of foamed plastic material in the container panels, it should be noted that side, top, and bottom panels having a uniform density of about two to three pounds per cubic foot have proven to provide ample structural strength in a shipping container having typical dimensions of 2 ft. x 2 ft. x 2 ft. In the event additional structural strength is required, the container panels may be provided with relatively high density strengthening sections in accordance with teachings of the prior art. In addition, at least the exterior faces of the side, top, and bottom panels of the container are preferably provided with tough skins so as to resist scufiing during handling and to resist penetration by a fork lift, or equivalent handling implements. Such tough skins may be variously provided, as discussed in the above-referenced copending application. In this regard, the skins may, for example, be formed during molding of the panels by chilling the mold to thereby provide integral relatively high density tough skins on the faces of the panels adjacent the chilled surfaces of the mold.
There are, thus, provided by the present invention, knock-down shipping containers of foamed plastic material. A container in accordance with the present invention comprises interlocking side panels 12, and top and bottom panels 13 and 14. The side panels may be interlocked with each other by means of the complementary interlocking means 16 and 17 at the opposite ends of the respective panels to define a rectangular marginal side wall. The side wall, as thus defined by the side panels, may then be placed upon the bottom panel 14 with lugs 27 thereof engaging the side panel air spaces 23, and the portions of the side panels between the air spaces and interior faces thereof being engaged between the lugs and the boss 26 in wedge fitting relationship. The open container may then be packed and the top panel 13 positioned atop the side wall and engaged with the side panels in a manner similar to that of the bottom panel. The straps 28 are secured to the rings 29 in tightly cinched relationship about the respective panels to thereby hold same in rigid unyieldable assembled positions during shipment of the container. At the destination point, the straps are uncinched and the top panel of the container is removed. Subsequent to unpacking of the container, the interlocking side and bottom panels maybe readily disassembled. In this regard, the entire side wall may, for example, be first vertically withdrawn from the bottom panel. One of the side panels may then be vertically withdrawn from the other side panels whereupon the remaining side panels can be readily disassembled. The knocked down container panels can thereafter be shipped to their point of origin, or elsewhere, with a minimum requirement of storage space during return shipment.
Inasmuch as the container panels are of foamed plastic, a container formed of such panels possesses excellent thermal insulating properties, is of relatively light weight, and possesses other desirable characteristics which are typical of foamed plastic. By virtue of the tough skin at the exterior faces of the container panels, the container is highly resistant to scufiing and substantially impermeable to handling implements, or the like. Knock-down shipping containers, in accordance with the present invention, may be provided in a variety of sizes, ranging, for example, from the relatively small two-foot cubical pack-aging container specifically mentioned hereinbefore, to relatively large cargo containers having dimensions of the orders of 6 ft. x 6 ft. x 8 ft. Throughout this range of sizes, the previously noted density of about two to three pounds per cubic foot provides adequate structural strength of the container. Under some circumstances, particularly with containers of larger size, greater structural strength may be desired in which case the density of the panels may be increased, or multi-density panels of the type described in the aforementioned prior art may be employed.
Although the invention has been described hereinbefore with particular reference to particular preferred embodiments thereof, it will be appreciated that numerous variations and modifications may be made therein without deextending vertically therethrough, substantially rectangular top and bottom panels of foamed plastic having outer peripheries dimensioned to substantially correspond to the outer periphery of said side wall, said top and bottom panels having central rectangular bosses dimensioned to substantially correspond to the inner periphery of said side Wall, said top and bottom panels having pluralities of lugs disposed between the side edges thereof and the periphery of said bosses, said lugs having a width substantially equal to that of said air spaces of said side panels, said top and bottom panels disposed at the opposite ends of said side wall with said bosses engaging the inner periphery of said side wall and said lugs engaging said air spaces of said side panels, and selectively operable fastening means securing said side, top, and bottom panels together in unyielding relationship.
2. A shipping container according to claim 1, further defined by the side edges of said bosses and of said lugs being bevelled to engage the interior of said side Wall and said air spaces with a wedge fit.
3. A shipping container according to claim 1, further defined by said side, top, and bottom panels having tough skins at the surfaces thereof.
4. A shipping container comprising a plurality of substantially rectangular side panels of foamed plastic, said panels each having tongue means projecting longitudinally from an end thereof and complementary groove means formed in a side face adjacent the opposite end thereof, said panels each having a longitudinally elongated rectangular air space extending vertically therethrough, said panels disposed with the tongue means of one engaging the groove means of another to define a rectangular marginal side wall, substantially rectangular top and bottom panels of foamed plastic having outer peripheries dimensioned to substantially correspond to the outer periphery of said side wall, said top and bottom panels having central rectangular'bosses dimensioned to substantially correspond to the inner periphery of said side wall, said bosses having bevelled side edges, said top and bottom panels having pluralities of substantially rectangular lugs disposed intermediate the side edges thereof and the periphery of said bosses, said lugs having a width substantially equal to that of said air spaces of said side panels, said lugs having bevelled side edges, said top and bottom panels disposed at the opposite ends of said side wall -with said bosses enga ing the inner periphery of said side wall and said lugs engaging said air spaces of said side panels, and straps detachably secured between opposite ends of said bottom panel and extending around adjacent ones of said side panels and said top panel in tightly cinched relationship.
5. A shipping container according to claim 4, further defined by the surfaces of said side, top, and bottom panels having tough skins thereat.
6. A collapsible container comprising four identical Walls formed of foamed polyurethane and each having inner and outer panels interconnected by spaced Wall portions to define internal air spaces between the panels, each wall having a pair of vertical ribs extending from one end and a pair of mating vertical slots along a side adjacent the other end whereby said walls are adapted to interlock to form a square peripheral wall structure, said walls in combination having a continuous pair of grooves longitudinally about top and bottom edges; a pair of like top and bottom members also formed of foamed polyurethane and having air pockets therein, said members each having a pair of ribs upon one surface about the periphery thereof and dimensioned to interlock with the edge grooves on said walls to establish a double interlock between assembled walls and top and bottom members, and a pair of straps adapted to extend about assembled walls and top and bottom members in removably clamping relation to firmly join same together.
References Cited UNITED STATES PATENTS Ioern.
Sprague et al.
Morrison 220-4 X Rouse 2203 X FOREIGN PATENTS Italy. Norway. Switzerland.
THERON E. CONDON, Primary Examiner.
JAMES R. GARRETT, Examiner.