US3675765A

US3675765A - Palletized load

Info

Publication number: US3675765A
Application number: US88613A
Authority: US
Inventors: Norbert J Melsek
Original assignee: Signode Corp
Current assignee: Signode Corp
Priority date: 1970-11-12
Filing date: 1970-11-12
Publication date: 1972-07-11
Anticipated expiration: 1989-07-11
Also published as: CA967121A

Abstract

A composite package consisting of an articulated fiberboard pallet or platform, a semi-fragile article positioned thereon, an inner heat-shrinkable plastic film shrunk tightly about and partially enclosing the article and platform and holding the latter partially folded about the article, an articulated outer box-like fiberboard cover telescopically received over the platform, article and film and interlocked with the platform, and a loop of strapping material encircling the fiberboard cover and maintaining the pallet and cover in their interlocking relationship. A method of assembling such a package.

Description

United States Patent Melsek 1 July 11, 1972 s41 PALLETIZED LOAD FOREIGN PATENTS 0R APPLICATIONS [72] Inventor: Norbert J. Melsek, Chicago, Ill. 643,984 7/1962 Canada ..206/ A [73] Assignee: Signode Corporation, Chicago, 111. OTHER PUBLICATIONS Filedl 1970 Brochure titled Poly Bag Shrink Pallet Covers, published by Cadillac Products, Inc. [21] Appl' 88613 A Disccusion of Shrink Polyethylene Pallet Covers," by J.

M. Bills, Cadillac Products, Inc.

[52] US. Cl. ..206/46 FN, 206/46 M, 206/60 A,

206/ A Primary Examiner-M. Henson Wood, Jr. 51 1 int. Cl ..B65d /00 Aswan Examlner-Bdwln Grant [58] Field of Search ..229/D1G. 12, 43; 206/65 s, Mama-Edward 206/45.33, 46 M, 46 FN, 46 FR, 45.14, 60 A, 78 B,

80 A; 53/30 [57] ABSTRACT A composite package consisting of an articulated fiberboard [56] References Cited pallet or platform, a semi-fragile article positioned thereon, an inner heat-shrinkable plastic film shrunk tightly about and UNlT D STATES PATENTS partially enclosing the article and platform and holding the latter partially folded about the article, an articulated outer 3,522,688 8/1970 Kahwoda et a1. ..206/65 S box fike fiberboard Cover telescopically received Over the 3,508,375 4/ 1970 Myers ..53/30 2 458 695 1/1949 Ed I 206 46 M platform, article and film and interlocked with the platform, 2 l 4 B eston 1 UX and a loop of strapping material encircling the fiberboard aufnann et l 3 cover and maintaining the pallet and cover in their inter- 2'790'544 4/1957 wlmon et "206/46 FN locking relationship. A method of assembling such a package. 3,347,365 10/1967 Funkhouser. ..53/30 x 3,529,717 9/1970 McDougal ..206/65 S 2 Claims, 12 DrawingFigures PKTE'N'TEDJUL 11 I972 3,675,765

sum 2 OF 3 //VVENTOR.' IVORBERT J. MELSEK PATENTEDJUL 1 1 I972 SHEET 30F 3 INVEN TOR.

IVORBEHT J. MELSEK PALLETIZED LOAD The improved package which comprises the present invention, as well as the method by means of which the package is assembled, has been designed for use in connection with the packaging of semifragile articles, as for example, medium size items of furniture having moving parts such as sliding drawers, swinging or sliding doors or panels, and other parts which ordinarily must be secured in fixed relationship when conventional packaging thereof is resorted to. Additional articles of a semi-fragile nature which readily lend themselves to the present packaging method are various tables or cabinets having elongated depending supporting legs which are incapable of withstanding lateral stresses and which, therefore require trussing force before satisfactory packaging thereof can be accomplished. The invention is, however, not limited to such articles and, if desired, the invention may, with or without modification as required, be employed in connection with the packaging of a wide variety of articles, or groups of articles, whether the same have moving or fixed parts, and regardless of the shape or outline thereof. irrespective of the particular article which is selected for packaging, the essential features of the invention are at all times preserved.

It has long been the practice to enclose an article, or a group of stacked articles, in a loosely fitting bag of a heat-shrinkable plastic film and then subject the bag to heat sufficient to cause the bag ultimately to shrink into conforming engagement with the article or articles. In the present state of the art it has also been the practice to thus package a palletized article by causing the bag upon heat shrinking thereof, to envelop at least the rim portion of the pallet so that the vertical component of film shrinkage pulls the article downwardly against the upper face of the pallet and anchors the article in position thereon.

Such heat shrinking of a plastic film or bag with relation to an article which is supported on a pallet has heretofore been accomplished on the basis of the use of a film which shrinks isotropically, which is to say that the shrinkage factor of the film is equal in all directions so that the open-ended inverted bag which encompasses the article and the rim of the pallet shrinks vertically to the same extent which it shrinks horizontally. Thus, on the basis for example of a film which has a 30 percent shrinkage factor in all directions, there is inadequate horizontal shrinkage of the film to contract the lower open rim of the bag beneath the periphery of the pallet for holding purposes unless the height of the palletized article is extremely small, or unless the overhang of the bag below the rim of the pallet is unduly long. For this reason where a palletized article of appreciable height is concerned, it has been found necessary to restrain the rim portion of the bag against upward movement by mechanical means such as nailing, stapling or tucking portions of the rim of the bag into crevices or pockets which are provided either in the pallet or in the pallet-supporting structure. This procedure is invariably resorted to where the pallet is rectangular and the article of considerable height so that only the corners of the pallet become frictionally engaged by the film while the medial regions of the rim of the bag between adjacent corners pull upwardly beyond the general plane of the pallet.

Considering only the heat shrinking aspects of the present invention, it is contemplated that, in order to overcome the above-noted tendency of the lower rim of the plastic bag film to pull upwardly beyond the plane of the pallet, a film be employed which, when constructed in bag form, has a high transverse shrinkage factor which is on the order of three times its longitudinal shrinkage factor. Thus, when the bag is inverted over an article of appreciable height so that its lower rim region overhangs the pallet, even to a relatively small degree, the relatively high transverse or horizontal shrinkage factor involved will cause a large linear shrinkage or contraction of the rim of the bag beneath the periphery of the pallet before the relatively small vertical shrinkage factor is effectiveto pull the rim upwardly so that when the vertical shrinkage factor becomes effective on the bag, the net result is to pull the lower rim of the bag upwardly against the underneath side of the peripheral regions of the pallet, this despite the fact that the.

initial bag overhang is on the order of only a few inches. By the use of such a film material, the necessity for stapling or otherwise securing any portion of the rim region of the bag to the pallet is obviated and thus, material and labor costs are appreciably reduced where continuous packaging operations are concerned.

Apart from the heat shrinking aspects of the present invention, complete fiberboard enclosure of the article is contemplated so that not only is the article concealed from view when packaged, but it, together with the film which encloses it, is protected on all sides. Accordingly, after the article and portions of the platform have been enclosed in a heat shrink film as outlined above, an open-ended fiberboard or other rectangular cover member is telescopically positioned over the platform and the lower open rectangular rim thereof secured to the side edges of the platform, thus encompassing the film-enclosed article on five sides while the platform on which the article is supported constitutes the sixth side of the hexahedral structure or package. Preferably, the four side walls and the top wall of the cover member remain spaced from and out of contact with the article-enclosing film so that any shocks which are inadvertently applied to the cover member during handling of the package are assimilated by the cover member and are not transmitted to the film or the article contained therein. Even under conditions of severe shock wherein the cover member becomes dented, punctured or otherwise ruptured, the clamping pressure afforded the article by the tension in the film will permit the package to be completely inverted and subjected to rough usage or handling in such position without damage to the article of the film which encloses It.

In a preferred form of the invention, both the rectangular platform and the cover member are formed of fiberboard material, each being formed from a fiat fiberboard blank. The comer regions of the articulated rectangular platform is provided with rim flaps in the corner regions thereof and these rim flaps are capable of beingturned upwardly out of the plane of the blank and also interfolded together so as to provide a series of four pocket-like retention corners which, collectively, receive the four lower comer regions of the article resting on the platform. The plastic film is then applied to the article and platform in the manner previously described and the predominant lateral or horizontal heat shrink factor serves not only to anchor the article firmly on the platform, but it also serves to bind the four retention corners inwardly against the article and thus compress them and maintain them in their interlocked relationship.

After the article has thus been anchored to the platform by the heat-shrunk film, an inverted fiberboard cover member is telescoped over the film-encased article and platform so that the lower rim of the cover member encompasses the platform edges, as well as the four retention comers and, thereafter, a series of rim flaps which are provided on the platform blank are folded into interlocking relationship with a series of cooperating rim flanges on the cover member so that the platform then assumes a tray-like configuration within which the article is snugly nested. Finally, in order to secure the interlocked rim flaps and flanges in tight interlocked relationship, a loop of steel or non-metallic strapping is tensioned about the cover member in the general horizontal plane of the platform, and then the overlapping ends of the loop are sealed to each other, thus completing the package.

The provision of a packaged article or load such as has briefly been described above constitutes the principal object of the present invention. Other objects and advantages of the invention, not at this time enumerated, will readily suggest themselves as the nature of the invention is better understood.

In the accompanying three sheets of drawings forming a part of this specification, two illustrative embodiments of an article which has been packaged according to the principles of the present invention has been shown.

In these drawings:

FIG. 1 is a perspective view of a platform-supported article which is loosely covered by an inverted open-ended plastic bag with the open lower rim portion of the bag extending below the level of the platform preparatory to subjecting the bag to a heat shrinking operation;

FIG. 2 is a perspective view of the platform-supported article after the plastic bag has been subjected to a heat-shrinking operation;

FIG. 3 is a perspective view of the completely packaged article;

FIG. 4 is a plan view of the plastic bag, showing the same in its substantially flattened condition;

FIG. 5 is a perspective view of an articulated fiberboard platform or pallet blank representing a more specific embodiment of the present invention and showing the same partially folded to substantially its article-receiving condition;

FIG. 6 is a frag'mentory plan view of one corner region of the unfolded platform blank of FIG. 5;

FIG. 7 is a perspective view, similar to FIG. 5, showing the article to be packaged in position on the partially folded platform blank;

FIG. 8 is a perspective view, similar to FIGS. 5 and 7, showing the partially folded platform blank and article loosely enveloped in a heat-shrinkable film of bag-like configuration;

FIG. 9 is a perspective view, similar to FIG. 8, showing the film shrunk upon the article and the partially folded pallet;

FIG. 10 is a perspective view, similar to FIG. 9, illustrating a further step in the packaging of the article and wherein a fiberboard cover member is positioned over the palletized article and partially folded into interlocking relationship with respect to the platform;

FIG. 11 is a perspective view of the completed package; and

FIG. 12 is an enlarged sectional view taken on the horizontal plane indicated by the line 1212 of FIG. 11 and in the direction of the arrow.

Referring now to FIGS. 1 to 3 inclusive wherein the invention in itS broadest aspect is illustrated, it is desired that a load-supporting platform or pallet 10, on which there is loosely disposed an article such as an electric motor 12, shall, together with the article, be encased in a tightly shrunk film 14 of heat-shrinkable plastic material (FIG. 2) and the resultant composite package component then covered with an outer box-like protective container 16 (FIG. 3) which conceals the article and film and protects the latter from being punctured or otherwise ruptured during handling or shipment. It will be understood that although the article 12 may be relatively massive it is not necessary that the same be nailed or in any way secured to the platform inasmuch as the tension which is developed in the film 14 is adequate to force the article hard against the upper surface of the platform, and also to exert generally radial inward components of force on the article in all directions to prevent shifting thereof after the heat shrinking ofthe film has been performed.

Before entering into a detailed description of the present method of producing a palletized article, it should be understood that the terms pallet and platform are used interchangeably and that any flat transportable base structure on which the article undergoing packaging is supported is to be considered as a pallet, regardless of whether or not such structure is provided with legs or other elevating means whereby it may receive therebeneath the tines of a fork truck.

The platform 10 selected for exemplary purposes herein is of rectangular configuration and it may be comprised of wood of a thickness which renders the same substantially rigid, while the film 14, prior to heabshrinking thereof, assumes the form of a commercially available bag 18 (FIGS. 1 and 4) which is pulled over the motor and platform in telescopic fashion so that the bag presents an open lower rim portion 20 and a closed top portion 22. The bag is constructed from a heatshrinkable material such as polyethylene or polyolefin which is extruded from a molten resin through an annular die, expanded by a blow-up" operation, and then stretched in a machine direction by suitable nip rolls while the material is still soft, thus imparting to the film a molecular orientation which is largely longitudinal but which possesses some transverse molecular orientation. The film is slit along one edge as it emerges from the nip rolls, leaving the other edge folded, and the folded material is then continuously wound on a core with the predominant molecular direction still extending longitudinally. No claim is made herein to any novelty associated with such production or processing of the film material, it being deemed sufficient to point out that in the completed tubular bag, the predominant molecular direction is circumferentially, i.e. horizontally as viewed in FIG. 1, while a lesser degree of molecular orientation is present in a vertical direction.

To attain this particular biaxial molecular orientation in the completed bag, the bag film is severed from the core on which it is wound and the severed sheet .of film is folded along a medial fold line which extends parallel to the direction of extrusion so as to bring the side portions of the folded sheet together in face-to-face contact, after which the meeting longitudinal edges of the folded sheet are heat-sealed or otherwise secured together, thus producing an open-ended pocket between the sides of the sheet produced by the folding thereof.

Roughly speaking, the heat shrink factor of the plastic material is a function of the molecular orientation so that when the bag 18 is subjected to the action of heat at a predetermined temperature and for a predetermined length of time, as the bag emerges from the heating operation and cooling sets in a very appreciable reduction in the diameter of the bag takes place while only a moderate reduction in the axial extent of the bag results. Specifically, and for optimum results according to be present invention, the heat shrink factor in the vertical direction of the inverted bag of FIG. 1 is approximately one-third of the heat shrink factor in the circumferential or horizontal direction. For packaging semifragile articles such as the article shown in FIG. 7, it has been found that a bag film material on the order of from 4 to 6 mils is extremely satisfactory for yielding the desired horizontal and vertical shrinkage of the film. However with sturdier articles such as the motor shown in FIG. 1, greater film thicknesses will ordinarily be employed. As will be pointed out in greater detail presently, this vertical and horizontal shrinkage difierential constitutes an important and essential feature of the present invention where relatively tall articles are undergoing packaging.

Referring again to FIG. 1 wherein the inverted plastic bag is shown as being telescopically received over the motor 12 and platform 10, and also to FIG. 4, wherein a partially opened bag is shown, it will be understood that the bag, in its free state, is of rectangular outline and presents two thicknesses of the molecularly oriented material, the side edges of the bag being in the form of longitudinal heat-sealed seams 24 and the bag bottom 26 being in the form of a l fold. The mouth of the bag exists by reason of the two adjacent linearly straight bag edges 28. The bag is opened up by spreading these two contiguous edges 28 apart and it is then pulled over the article in a manner similar to pulling a stocking over a foot. Since, in the case of the electric motor 12, the article undergoing packaging presents a horizontal and generally rectangular cross section, the bag sides are spread to conformable rectangular cross section so that the envelope which encompasses the article presents four generally vertical sides, two of which are medially divided by the longitudinal bag seams 24 and with these seams extending over the top of the article and terminating in a pair of generally triangular folded sections 30 which lie flush against the aforementioned horizontal top portion or v wall 22 which is established by the closed edge region of the flattened bag of FIG. 4.

According to the present invention, the lower rim portion 20 of the thus opened and inverted bag 18 is pulled downwardly and overhangs the platform 10 in skirt or apronlike fashion as clearly shown in FIG. 1, this rim portion hanging freely and requiring no attachment whatsoever to the platform or to the article supported thereon. It will be understood,

of course, that to attain such free hanging condition of this rim portion 20, the platform will be supported in an elevated position, as for example by pallet legs, a pedestal or other support (not shown) from a foundation surface.

The film-draped article is then subjected to a heat shrink operation by means of which the film 14 is caused to shrink largely in a circumferential horizontal direction and, to a lesser extent, in a vertical direction about the article and platform. Preferably, the heat-shrinking operation is accomplished by exposing the film-draped article 'to heated air by passing the same through a suitable oven. However other heating means such as exposing the film to the action of infra red heat radiation are contemplated. Regardless of whether radiant heat or heat of conviction is used, the resultant heatshrinking characteristics of the film remain substantially the same. It will be understood that while heat is actually being applied to the film, the latter is softened to such an extent that even the action of gravity on the film serves to exert a sagging efiect although some shrinkage may take place. The actual effective film-shrinking takes place after such heat conditioning of the film has terminated and the film comes into contact with the cool air as it emerges from the oven. Thus, in the following description and in the appended claims, reference to a heat shrinking operation is intended to embody not only the heating effect but also the necessary subsequent cooling operation.

It is to be noted at this point that by reason of the particular molecular orientation of the bag film 14 wherein such orientation is predominantly horizontal as far as the bag 18 is concerned, as soon as the bag is subjected to the effective shrinking operation a large and rapid circumferential shrinking of the bag takes place, thus the rim region 20 of the bag beneath and within the vertical confines of the platform 10. This shrinking of such rim region 20 takes place within a few seconds and before the relatively slow vertical shrinkage of the bag walls has had time to pull this rim region upwardly above the general plane of the platform. The net result of this is that when the smaller vertical shrinkage, of which the bag film is capable, has been completed, much of the rim portion 20 is drawn upwardly into tight engagement with the underneath' side of the platform, particularly at the comer regions thereof as clearly shown in FIG. 3. By thus utilizing a film which has a predominant horizontal shrinkage factor, and one which functions rapidly during the heat shrinking operation, it is unnecessary to nail, staple or otherwise restrain any portion of the rim 20 against upward movement and thus, from the time the article is initially loosely set upon the platform 10 until such time as it emerges from the heat shrinking operation, no manual operations other than placing the inverted bag 18 over the article and platform are required.

In order to render the assembled article 12 and platform or pallet 10 suitable for shipping or handling, the previously mentioned outer container 16, which preferably is in the form of a rectangular fiberboard or other suitable cover shell, is inverted and telescoped over the article and the rectangular rim region thereof is nailed or otherwise secured as indicated at 36 to the four edges of the platform 10. The completed package is thus in the form of a hexahedron wherein the outer cover or container supplies the four side walls 38 and a top wall 40, while the platform 10 supplies the bottom wall.

The outer container or cover member 16 not only conceals the film-encased packaged article 12, but it also constitutes a protective shell which facilitates handling of the package as a whole and shields the film 14 from damage during such handling. Because the shrunk film 14 remains out of contact with any portion of the cover member 16 which lies above the plane of the platform 10, any puncturing or denting of the cover member incident to rough handling of the package, will not be transmitted to the cocoon-like film l4 and the article which it encloses, this being true even when the package is handled in an inverted condition.

It is to be noted from an inspection of FIG. 3 that due to the rapid initial circumferential shrinking of the lower rim region 20 of the bag 18, and the subsequent vertical shrinking of the bag sides, the four corner regions of the platform 10 are firmly frictionally engaged by the lower rim region 20 of the inverted bag as film shrinking initially takes place, while the medial region of the side edges of the platform are also frictionally engaged to a lesser extent so that when the bag film assumes its finally shrunk condition, an intumed peripheral rim of the plastic material such as has been indicated at 42 in FIG. 3 lies flush with the underneath face of the platform, this continuous rim constituting the only exposed portion of the bag film 14. The remainder of the bag film tends to closely hug the article and the vertical component of tension existing in the film, although it is slower in performing its shrinking function during the heating cycle, nevertheless exerts considerable downward thrust on the article 12 and serves to securely bind the article on the upper surface of the platform 10 against lateral shifting.

In a more specific aspect, the present invention is particularly well adapted for use in connection with the packaging of semifragile articles as, for example, articles of furniture having moving parts such as sliding drawers, swinging or sliding door panels and the like which, where conventional packaging methods are concerned, ordinarily must be secured in fixed positions before the packaging components are applied to the articles. The invention is especially useful in connection with such articles of furniture as cabinets, chairs, tables, television or radio consoles and the like which present relatively fragile supporting legs, hinged mirror frames and the like which, ordinarily, must be braced or cushioned to withstand normal handling usage for shipment purposes. Such articles, when packaged according to the present invention, substantially eliminate the need for bracing inasmuch as the plastic film which is heat-shrunk over the article frictionally engages the moving parts thereof and presses them in their closed positions. In the case of fragile supporting legs, or mirror frames and the like, the heat shrunk film also functions in the manner of a truss and frictionally engages such parts and rigidifies them by establishing, in effect, a series of webs which extend, variously, between the fragile parts themselves, and between such parts and other more rigid portions of the article, as well as the platform, thereby establishing reaction forces which brace and cushion the parts against even slight displacement from their normal positions.

For exemplary purposes, the semi-fragile articles selected for illustration herein is in the form of a conventional kitchen cabinet 50 having the usual body portion 52 which is supported by legs 54, a sliding drawer 56 and a swinging door or panel 58. The article 50, in its packaged condition, is supported on an articulated fiberboard pallet or platform 60, the blank for which is fragmentarily shown in FIG. 6, and which platform is shown in FIG. 5 is a partially folded or erected condition. The packaging of the article is accomplished in a manner similar to the packaging of the article 12 of FIG. 1 by partially encompassing the article and platform with an appropriately sized plastic bag 18 (FIG. 8) which may be identical with the bag of FIG. 4, and thereafter applying an outer articulated fiberboard container or cover member 64 (FIGS. 10 and 11) to the platform 60 and causing the cover member and platform to become interlocked together, all in a manner that will be made clear presently.

Considering now the nature of the articulated platform 60 and its associated blank, and referring specifically to FIGS. 5 and 6, such platform is preferably formed from an originally rectangular sheet of fiberboard material which is slotted, scored or otherwise provided with fold lines which enable it to be folded into tray-like configuration. The four corner regions of the fiberboard blank are identical and symmetrical, one such corner region being fragmentarily shown in FIG. 6. The term fiberboard" as employed herein is intended to include a wide variety of sheet materials such as substantially rigid commercial fiberboard, impregnated or otherwise treated and pressed fibrous sheet material, laminated paperboard, corrugated or otherwise, and other sheet materials capable of being rendered foldable to produce the type of articulation required by the invention and described herein.

The blanks (FIGS. and 6) is provided with two parallel longitudinal fold lines 70 and two parallel transverse fold lines 72, the

lines

70 and 72 intersecting in tic-tac-toe fashion and defining a central rectangular tray base or platform proper 74. Considering only the lower right hand comer region which is illustrated in FIG. 6, a pair of

narrow slots

76 and 78 are cut inwardly and longitudinally from the edge of the blank and terminate at the adjacent transverse fold line 72. These two

slots

76 and 78 establish three end edge flaps including a bent narrow end edge flap 80, a second narrow end edge flap 82 and a relatively wide medial end flap 84. The medial and second end edge flaps 84 and 82 are provided with transversely extending

dual fold lines

86 and 88 therealong. The end edge flap 80 need not be dual scored inasmuch as this flap does not become folded individually in the completed traylike platform structure.

Each corner region of the blank is further formed with a single transversely extending narrow slot 90 which establishes a single relatively narrow side flap 92 and a wide medial side edge flap 94, both such side edge flaps being provided with longitudinally extending

dual fold lines

96 and 98 respectively. The slot 90 extends inwardly to the longitudinal fold line 70. The extreme corner portion is cut away as indicated by the partial dotted line rectangle 100. It will be understood that the other three corners of the blank are similarly slotted, scored and relieved to provide corresponding fold lines.

Referring now to FIG. 7 in conjunction with FIGS. 5 and 6 wherein the manner in which the platform blank is folded into tray shape for reception of the article 50 therein, various folding sequences may be resorted to but, for exemplary purposes, one such manner of folding will be described In accordance with the invention, the blank is initially folded to provide a series of four upstanding L-shaped composite retention comers 102 (see also FIG. 8) which are formed by first folding the end edge flaps 80 upwardly on the fold lines 72 to vertical positions after which the blank is folded along the adjacent longitudinal fold lines 70 so that the end edge flaps 80 assume onedge positions which are coincident with the fold lines 72, as shown in dotted lines in FIG. 5. Thereafter, the end edge flaps 82 are folded to vertical positions along the transverse fold lines 72 and then are folded over along the dual fold lines 88 so that they encompass or straddle the upper edges of the vertical flaps 80. To complete the retention corners 102, the side edge flaps 92 are similarly erected to vertical positions along the fold lines 70 and are then folded inwardly upon themselves along the dual fold lines 96. The composite retention comers serve not only to assist in centering the article on the platform, but they also serve as reaction members to assimilate the inward thrust of a tensioned strapping loop which encompasses these corners in a manner and for a purpose that will be described presently. Prior to placement of the article 50 upon the platform 60, the medial end and side edge flaps 84 and 94 respectively are left unfolded and in the general plane of the fiberboard blank.

Still referring to FIG. 7, with the articulated platform thus partially erected, the article 50, which in the exemplary form illustrated is in the form of a kitchen cabinet, is positioned with its back side lying flush against the platform base 74 and nested within the quadrilateral confines of the four retention corners 102. At this time the top wall of the cabinet and the extreme ends of two of the legs 54 bear against the folded end edge flaps 82 and the folded side edge flaps 92 and thus rigidify the formerly loosely folded retention comers 102.

After the article 50 has thus been positioned on the platform base 74, a plastic bag which may be substantially identical with the previously described bag 18, and which has been identically designated in FIGS. 4 and 8 to 11 inclusive, is loosely and telescopically positioned over the partially palletized article 50 as shown in FIG. 8 so that at least the corner rim regions of the bag overhang and extend below the level of the platform base 74 while the medial regions of the rim sides rest loosely upon the still unfolded end and side edge flaps 84 and 94.

At this time, and with the end and side edge flaps 84 and 94 still unfolded, the film material 14 which comprises the bag 18 is then subjected to heat shrinking, after which the shrunken film assumes the condition in which it is illustrated in FIG. 9. The same phenomena of rapid inward or centripetal shrinking of the lower rim region 20 of the bag 18 as was prevalent in connection with the palletizing and packaging the electric motor 12 of FIGS. 1 to 3 inclusive obtains in connection with the shrinking of the bag 18 over the palletized cabinet 50 of FIG. 9 and need not be described in detail herein except to point out that such shrinking causes the four corner regions of the platform base 74 to be frictionally engaged by the film and held against upward movement without necessitating special restraining devices. It is also to be particularly noted that during such shrinking operation the predominantly horizontally molecularly oriented film 14 tends to follow the exterior contour of the article upon which it is being shrunk so that, in the case of the illustrated cabinet 50, the distal or lower ends of the four cabinet legs 54 frictionally engage the film 14 while the intervening portion of the film assumes a large radius concave film area, this area being under relatively high tension so that the four legs are reinforced and trussed at their extreme ends by continuous strut-like film areas which preclude the necessity for utilizing extraneous leg reinforcing means such as leg braces or struts, cushions or the like. Additionally, inasmuch as the top wall portion of the shrunk bag bears downwardly upon the sliding cabinet drawer 56 and the swinging cabinet door panel 58, these movable members are securely held in their closed positions by the film and need no temporary fastening devices such as are commonly employed in connection with the conventional packaging and shipment of such cabinets and similar articles of furniture.

The packaging of the cabinet 50 is completed by telescopically applying the previously mentioned open-ended outer box-like fiberboard cover member 64 the article 50 and film 14 so that the lower rectangular rim region of the cover member encompasses the platform base 74 as well as the four retention corners 102 and rests upon the still unfolded medial side and end flaps 84 and 94. The cover member 64 is provided with side walls 106, end walls 108, a top wall and has a lower rim which is provided with relatively

narrow rim flanges

116 and 118 which are connected to the side and end

walls

106 and 108 by

fold lines

120 and 122 respectively. With the cover member 64 thus seated on the unfolded edge flaps 84 and 94 of the platform base 74, these latter flaps are then folded over the

flanges

116 and 118 along the

dual fold lines

86 and 98 as shown at the lower left hand region of FIG. 10 and, after such folding, the encompassed

rim flanges

116 and 118, together with the now folded medial edge flaps 94 and 84 are folded upwardly to vertical positions in the manner indicated at the lower right hand side of FIG. 10, and also as shown in FIG. 12, thus completing the shallow tray-like structure of the carton blank.

The folding of the edge flaps 94 and 84 about the

rim flanges

116 and 118 and the erection of the thus interlocked flaps and flanges to their vertical positions establishes four regions of interlock 124 between the four vertical walls of the cover member 64 and the four peripheral edges of the platform base 74. The specific nature of such interlock regions is best illustrated in FIG. 12 wherein it will be observed that the illustrated interlock embodies four thicknesses of fiberboard material including the cover member end wall 108, the inner fold of the carton blank rim flap 84, the end flange 118 of the cover member and the outer fold of the edge flap 84.

In order to secure these four interlocks in position against unfolding, and as shown in FIG. 11, the cover member 64, together with its contained article 50 and encompassing film 14, is turned on its side and a loop of steel or non-metallic strapping material 126 is caused to encircle the lower rim region of the cover member 64, the loop encompassing the four interlock regions 124. The strapping loop is then tensioned by means of a suitable strapping tool and a seal 128 is applied to the overlapping ends of the tensioned loop, thereby completing the package.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings and described herein, nor to the specific method steps concurrently set forth since various changes in the details of construction as well as variations in the method steps, or in the sequence in which they are performed, may be resorted to without departing from the spirit of the invention. For example, by varying the extent of overhang of the lower rim region of the plastic bag 18 in either illustrated form of the invention, or by varying the shrinkage factor of the bag film in a vertical direction, the pattern of the exposed portions of the heat shrunk film on the underside of the platform 10 or the platform base 74, will be varied within certain limits. Under certain circumstances a complete continuous closed ring of the film material will be exposed, but with a shorter extent of overhang, or a greater vertical shrink factor, or a combination of both of these factors, only limited comer regions of the film 14 will be exposed on the underneath side of the platform or platform base. In any event, it is desirable that no portion of the film 14 shall be pulled upwards beyond the general plane of the platform base lest the hermetic seal which is established by the film 14 be destroyed. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described my invention, what I claim and desire to secure by letters patent is:

l. A film-encased covered palletized load comprising an articulated horizontal rectangular platform formed from a carton blank of substantially rigid but foldable sheet material, an article on said platform and constituting said load, a plastic film encompassing said article and the corner regions of the platform and heat shrunk therearound so that the film exists under tension in both a vertical and a horizontal direction, the film extending under each of said comer regions whereby the vertical tension therein is sustained by frictional engagement of the film with the underneath surface of the platform at said comer regions and with the top surface of the load, said film, prior to being heat shrunk around the article and platform, having a predominately horizontal shrink factor as compared to its vertical shrink factor, said platform being provided with a first series of interlocking and interfolded edge flaps which, in the carton blank, are hingedly connected to the platform and project outwardly from the comer regions thereof, said interfolded edge flaps extending vertically and serving to provide upstanding composite retention comers which lie inside the confines of the film, a box-like cover member having side walls, a top wall and an open lower rim, telescopically received over the film-encased article, the platform and said retention comers, said rim being conformable in shape to the outline of the platform and being disposed in contiguity wit the edges of the platform, said platform being further provided with a second series of edge flaps which, in the carton blank, are hingedly connected to the platform and project outwardly beyond the lateral confines thereof, a series of rim flanges hingedly connected to the lower edges of said side walls and substantially coextensive therewith, the edge flaps of said second series and said rim flanges being interfolded and lying exteriorly of the film-encased load so as to provide vertically disposed multi-layer interlocks between the cover member and platform for holding the former in position on the latter, and a loop of tensioned strapping encircling the lower region of the cover member including said interlocks, and the retention corners, and serving to force the interlocks against the adjacent walls of the cover member.

Claims

1. A film-encased covered palletized load comprising an articulated horizontal rectangular platform formed from a carton blank of substantially rigid but foldable sheet material, an article on said platform and constituting said load, a plastic film encompassing said article and the corner regions of the platform and heat shrunk therearound so that the film exists under tension in both a vertical and a horizontal direction, the film extending under each of said corner regions whereby the vertical tension therein is sustained by frictional engagement of the film with the underneath surface of the platform at said corner regions and with the top surface of the load, said film, prior to being heat shrunk around the article and platform, having a predominately horizontal shrink factor as compared to its vertical shrink factor, said platform being provided with a first series of interlocking and interfolded edge flaps which, in the carton blank, are hingedly connected to the platform and project outwardly from the corner regions thereof, said interfolded edge flaps extending vertically and serving to provide upstanding composite retention corners which lie inside the confines of the film, a box-like cover member having side walls, a top wall and an open lower rim, telescopically received over the film-encased article, the platform and said retention corners, said rim being conformable in shape to the outline of the platform and being disposed in contiguity wit the edges of the platform, said platform being further provided with a second series of edge flaps which, in the carton blank, are hingedly connected to the platform and project outwardly beyond the lateral confines thereof, a series of rim flanges hingedly connected to the lower edges of said side walls and substantially coextensive therewith, the edge flaps of said second series and said rim flanges being interfolded and lying exteriorly of the film-encased load so as to provide vertically disposed multilayer interlocks between the cover membEr and platform for holding the former in position on the latter, and a loop of tensioned strapping encircling the lower region of the cover member including said interlocks, and the retention corners, and serving to force the interlocks against the adjacent walls of the cover member.

2. A film-encased covered palletized load as set forth in claim 1, wherein each edge flap of the first series is folded along a medial longitudinally extending fold line over the distal edge of the adjacent side flange so as to make coextensive face-to-face contact with the opposite sides of the latter, and the folded edge flaps and the flanges lie in substantial contiguity with the adjacent side walls of the cover member.