US3255870A

US3255870A - Display carton

Info

Publication number: US3255870A
Application number: US406260A
Authority: US
Inventors: John F Peck
Original assignee: PECK Inc
Current assignee: PECK Inc
Priority date: 1964-10-26
Filing date: 1964-10-26
Publication date: 1966-06-14
Anticipated expiration: 1983-06-14

Description

June 14, 1966 J. F. PECK 3,255,870

DISPLAY CARTON Filed Oct. 26, 1964 3 Sheets-Sheet 1 INVENTOR JOHN F P50 J. F. PECK DISPLAY CARTON June 14, 1966 3 Sheets-Sheet 2 Filed Oct. 26. 1964 INVENTOR JOHN F PFC/f BY mn L J. F. PECK DISPLAY CARTON June 14, 1966 Filed Oct. 26, 196% INVENTOR JOHN F PEG/r I r A v BY E O O vm ATTORNEY United States Patent 3,255,870 DISPLAY CARTON John F. Peck, North Oaks, Minn, assignor to Peck, Inc., St. Paul, Minn, a corporation of Minnesota Filed Oct. 26, 1964, Ser. No. 406,260 15 Claims. (Cl. 206-4534) This application is a continuation-impart of my previous application, Serial No. 295,156, filed July 15, 1963 for Display Carton.

This invention relates to an improvement in display cartons and deals particularly with a tray having a plastic enclosure therein designed for containing a product so that it can be viewed by the consumer.

During recent years a considerable number of packages have been produced designed for containing a product so that the product is visible to the purchaser. Many such packages comprise a blister or preshaped plastic container marginally secured to a backing board of paperboard or similar material. In some cases, the marginal edges of the transparent bubble or blister are heat sealed to the surface of the reinforcing card. In other cases, the marginal edges of the blister are sandwiched between a pair of paper panels, the hollow portion of the blister projecting through an aperture in at least one of the panels. While such structures are very successful, they usually require heat sealing or gluing equipment of a particular type in order to function effectively. If the marginal edges of the blister are heat sealed to the backing card, it is necessary to provide a heat sealing unit which fits the shape of the package so as to seal the marginal edge thereof. On the other hand, if the edges of the blister are sandwiched between a pair of panels, a double panel of paperboard is required, and the two panels must be of suflicient size to be marginally sealed together beyond the periphery of the marginal edges of the blister. While this is not particularly a problem for a producer who uses the packages in large volume and in which the size of the package does not vary, it is not nearly as suitable for a producer of smaller quantities of product or where the sizes of the products being packaged vary at relatively frequent intervals.

However, of' possibly more importance to the consumer lies in the fact that in a package of the type described, the goods are somewhat difiicult to remove. The edges of the blister are sealed to the paperboard in such a manner that the goods cannot accidentally escape, and as a result it is diflicult to open the package and remove the product. Furthermore, during the opening process, the backing panel has to be torn away from the marginal edges of the blister, and the consumer often loses control of the product during this process. It is diflicult to grasp the projecting blister due to the fact that it is usually provided with rounded edges and often the blister is bent inwardly against the contents during the opening procedure. Accordingly, while packages of the type usually used are desirable from a display standpoint, they often prove to be quite an annoyance to persons attempting to remove the contents.

It is an object of the present invention to provide a plastic blister of a suitable type having the usual marginal flange arranged on a common plane. This blister is contained within a shallow tray including a base panel against which the marginal flange engages and peripheral walls are usually extending upwardly at right angles to the base panel. At least two of these walls are provided with flanges hinged to the upper edge thereof and foldable inwardly of the walls to which they are hinged. When the transparent blister is in place, these flanges are folded down to overlie the marginal flanges of the transparent blister to hold the same engaged.

A feature of the present invention resides in the fact that with the constnlction described, the transparent blister may be held in placewithout the use of heat sealing equipment or adhesive to secure the blister to the backing card. The flanges on the walls of the tray when hinged downwardly toward parallel relation to the walls from which they are hinged have a natural tendency to swing inwardly. As a result, the edges of the flanges encircling the blister are effectively held in position. However, if it is desired to remove the contents of the package, this may be done in any one of a number of ways such as by tearing two adjoining corners of the tray and sliding the tray through the open side thus formed. In this manner, the blister remains intact and can serve as a container for the contents until they are used up.

A further feature of the present invention resides in the provision of a package of the type described which may be readily closed by placing the package contents into the blister, forming the tray with the flanges folded inwardly, and forcing the tray down over the blister until the marginal flanges of the blister engage the base of the tray. When this takes place, the flanges of the tray will normally flex inwardly and engage the flanges of the blister to hold the two parts assembled.

A further feature of the present invention resides in the fact that the package may be used to contain products of different types such as Christmas tags, labels, and the like. In this case, the bubble is formed with two compartments each of proper size to accommodate a series of cards or tags, the two compartments being separated by a strip, portions of which are coplanar with the marginal edges of the blister, and a portion of which projects beyond the plane of the marginal edges of the blister. This projecting portion may extend through a suitably shaped aperture in the base of the tray to prevent the relatively thin cards or tags from sliding from one compartment to another.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims:

In the drawings forming a part of the specification:

FIGURE 1 is a perspective view of the completed package.

FIGURE 2 is a sectional view taken on. the line 2-2 of FIGURE 1.

FIGURE 3 is a transverse sectional view through the tray, the position of the section being indicated by the lines 3-3 of FIGURE 1.

FIGURE 4 is a transverse sectional view, the position of the section being indicated by the line 4-4 of FIG URE 1. i

FIGURE 5 is a horizontal sectional view through a corner of the tray illustrating the manner in which the walls are held together.

FIGURE 6 is a view similar to FIGURE 5 showing a modified way of holding the carton corners engaged.

FIGURE 7 is a perspective view of a modified form of package construction.

FIGURE 8 is a top plan view of the package shown in FIGURE 7.

FIGURE 9 is an enlarged longitudinal section through the package the position of the section being indicated by the line 9-9 of FIGURE 8.

FIGURE 10 is an enlarged transverse section through the package, the position of the section being indicated by the line 10-10 of FIGURE 8.

FIGURE 11 is a diagrammatic view of the blank from which the tray of the modified form of construction shown in FIGURE 7 is made.

FIGURE 12 is a perspective view of another modified form of construction.

FIGURE 13 is a top plan view of the construction shown in FIGURE 12.

FIGURE 14 is a longitudinal vertical sectional view through the tray shown in FIGURES l2 and 13.

FIGURE 15 is a diagrammatic view of the blank from which the outer tray shown in FIGURES 12 to 14 is formed.

The particular apparatus illustrated in the drawings is designed to contain tags or cards of two different sizes and accordingly includes two separate compartments. It should be understood that changes might be made in this basic construction which would disclose an apparatus having more compartments or might have a single compartment. However, the particular construction illustrated has certain advantages for the applicants particular product.

The package A includes a tray-shaped member illustrated in general by the numeral and having a rectangular bottom panel 11, upwardly extending end wall panels 12, and upwardly extending side wall panels 13. In the particular arrangement shown, the side wall panels 13 are hingedly connected along their upper edges to flanges 14 which are slightly shorter in height than the side walls 13. Obviously, the end walls 12 could have similar flanges if the dimensions of the package were such as to require the retention of the ends of the transparent portion of the packages as well as the sides thereof.

The internal portion of the package is indicated in general by the numeral 15, and preferably comprises a sheet of transparent plastic film which has been suction formed or otherwise molded to form a pair of raised inverted trays or

blisters

16 and 17. A marginal flange 19 encircles the raised

portions

16 and 17 and lies on a common plane. Intermediate the bulged

portions

16 and 17 lies a connecting portion 20 which is coplanar with the flanges 19. Also in the particular arrangement illustrated, a transversely elongated rib 21 is provided which projects from the connection portion 20 in a direction opposite to the blisters or bulges 16 and 17. This rib 21 extends through an aperture or slot 22 in the base panel 11 to form a separator between the interiors of the two bulged

portions

16 and 17. The purpose of this arrangement is to provide a barrier between the compartments formed by the

blisters

16 and 17 so that relatively thin cards or tags cannot travel from one compartment to the other even though they might be thin enough to pass between the connecting portion 20 and the backing card 11. As both the tray and the compartment forming member are of relatively thin material, there is always a possibility that these two parts may bow apart to the extent necessary to prevent a thin card or tag to pass from one compartment to the other in the absence of the rib 21. In the event the package is used for other purposes, this barrier might not be required.

The corners of the tray may be held in rectangular relation either by means illustrated in FIGURE 5 of the drawings or the means illustrated in FIGURE 6 thereof. In FIGURE 5, corner flaps 24 are hingedly connected to opposite sides of the end walls 12, and are folded over the side walls 13 and adhered thereto. Obviously, the corner flaps 24 could similarly be connected to the ends of the side walls 13 and adhered to the end walls 12. FIGURE 6 illustrates a modified form of construction in which the corner flaps 24 are folded between the side walls 13 and the flanges 14 connected thereto. With this construction, the corner flaps are maintained in position by the fold line connecting the side walls 13 and the flanges 14, so that the requirement for an adhesive engagement is obviated.

As is indicatedw in FIGURES 3 and 4 of the drawings, the flanges 19 of the enclosure rest in face contact with the bottom panel 11 and are shaped to fit closely between the various side walls. The flanges 14 overlie the flanges 19 and retain the enclosure 15 within the tray without the need of heat sealing. The flanges 14 have a natural tendency to fold inwardly and upwardly and accordingly firmly hold the enclosure in place. As a matter of fact once the air enclosure 15 is engaged in the outer tray 10 beneath theflanges 14, it is difficult to remove the inner enclosure without the use of a knife blade or similar object to press one flange 14 against its adjoining side wall 13. However, the contents of the package may be easily removed by tearing two adjoining corners of the tray, such as the corners at one end of the bottom panel, and sliding the tray from the transparent enclosure while the enclosure is inverted, the contents remaining in the transparent enclosure.

The manner in which the tray and the transparent enclosure are assembled is somewhat of a matter of choice. However, the desired result can be readily accomplished after the tray is assembled and while the receptacle 15 is in inverted position. The contents are placed in the inverted compartment or receptacle 15, and the open side of the tray forced downwardly over the receptacle while the flanges 14 are folded against their respective side walls. During this operation, the marginal flanges 19 of the receptacle 15 hold the flanges 14 against their side walls until the flanges 19 pass the end of the flanges 14 at which time the flanges 14 may spring inwardly to lock the receptacle in place. This is most readily accomplished while the transparent receptacle 15 is supported in a pocket which holds the marginal flanges 19 in a common plane due to the flexible nature of the transparent receptacle. When the receptacle 15 is in place, the flanges 14 are of greater width than the distance between the upper edges of the side walls 13 and the walls of the bulged

portions

16 and 17, holding the flanges 14 in engagement with the flanges 19.

The package B illustrated in FIGURES 7 through 11 of the drawings is generally similar to the package A, 'but provides a somewhat more attractive appearance and also provides more area for a printed display for the goods packaged. The internal portion 25 of the package B may be identical to the internal portion 15 of the package A but in the form illustrated, comprises an inverted tray or blister of plastic film shown having a single compartment. The interted tray 25 includes a top panel 26 mar- 'ginally connected to downwardly and outwardly inclined end walls 27, and downwardly and outwardly inclined side walls 29. A marginal flange extends outwardly from the side and end walls, the tray being illustrated as including end wall flanges 30 and side wall flanges 31 which are connected at the corners as indicated at 32 (FIGURE 8 of the drawings) or to provide a continuous marginal flange. The under surface of the

flange

27, 29 is designed to lie in surface contact with the upper surface of the bottom panel 33 of the outer tray 34. As is indicated in FIG- URE 11 of the drawings, the outer tray 34 includes a bottom panel 33 which is of a width slightlygreater than the width of the internal portion 26, and which may be of a length substantially less than the length of the interior bubble or blister portion 25. The side edges of the bottom panel 33 are foldably connected along parallel fold lines 35 to side wall panels 36. The upper edges of the side wall panels 36 are hingedly connected along fold lines 37 to liner flanges 39. The ends of the side wall liner flanges 39 are tapered as indicated at 40 from points 41 to the upper corners of the side walls 36. The points 41 on each side wall liner panel 39 are spaced apart a distance substantially equal to the distance between the lower edges of the end walls 27 of the interior portion 25 at the juncture between the end walls 27 and the end wall 30. The liner flanges 39 are of a width which is prefera'bly slightly less than the width of the side walls 36 to which they are hinged.

The bottom panel 33 is hinged along fold lines 42 which preferably intersect the fold lines 35 at right angles to end walls 43. The end walls 43 are hingedly connected along their upper edges by fold lines 44 to end Wall liner flanges 45. The end wall liner flanges 45 are of proper length to extend from the upper edges of the end walls 43 to the lower ends of the end walls 27 at their I juncture with the end wall flanges 36. Thus when the end wall liner flanges 45 are folded inwardly as indicated in FIGURE 9 of the drawings, they engage against the end walls 27 of the interior portion at their juncture with the end wall flanges 30.

The end wall liner flaps 45 are preferably of such width as to be folded between the erected side walls 36 while the side wall liner flanges are folded against these sidewalls. The end wall liner flanges 45 may also be slightly shorter than the distance between the upper edges of the end walls and the end walls of the inner inverted tray 25. However, the side wall liner flanges 39 are wider than the distance between the upper edges of the side walls and the upper edges of the side walls 29 of the inverted tray 25'. As packages of this type are usually used to display the product, the inner inverted tray 25 is usually formed of transparent plastic. It should further be noted that the top panel 26 of the inner tray 25 is substantially on a common plane with the upper edges of the side walls and end walls of the outer tray.

Corner connecting flaps 46 are preferably connected to the side edges of the end walls 43 along continuations of the fold lines 35, and these corner connecting flaps are either adhered or interlocked with the side walls to hold the side and end walls in right angular relation to the bottom panel 33. The main purpose of the end wall liner flaps 45 is to conceal the end flanges 34) of the inner tray 25, and also to provide a display area advertising the product contained. Where no display is required, these panels may be attractively printed to enhance the appearance of the product. In operation, the outer tray 34 is formed on suitable equipment, and the corner flaps 46 locked or adhered to the side walls to hold the side and end walls in right angular relation to the bottom panel. Obviously, the corner flaps 46 could be hinged to the end edges of the side walls and locked or adhered to the end walls if preferred. The side wall liner flaps 39 are preferably folded inwardly at least to the extent necessary to insure the inward folding of the liner flanges 39 when the inner inverted tray 25 is inserted.

The tray 25 is preferably formed by vacuum molding or by a similar process. Usually a considerable number of similar trays are formed simultaneously and cut apart to form the individual trays. The trays are filled with the product while in upright position either manually or automatically. The formed outer tray 34 is then usually positioned over the filled inner tray, and the two parts are then forced together. During this operation, the side wall liner flanges 39 are folded substantially in surface contact with the side walls to which they are hinged. As soon as the side wall flanges 31 of the tray 35 pass the end edges of the side wall liner flanges 33, these liner flanges 39 swing inwardly over the flanges 31 until they engage the side wall 29 of the inward tray. This action is caused by the natural tendency of the paperboard or t similar material of which the outer tray is formed to return to the plane of the side walls 36. In actual practice, the flanges 39 snap into locking position as the

flanges

30, 31 move into contact with the bottom panel 33.

The end wall liner flanges 45 are then folded inwardly. This action again folds the end portions of the side wall flanges 3? outwardly toward the side walls 36. When the flanges 45 are folded down against the flanges 30 of the inner tray 35, the side edges of the flanges 45 pass beneath the diagonal end edges 40 of the side wall lining flanges 39 and the side wall flanges may again snap back against the side walls of the inner tray. The package is then complete.

Obviously, the end wall flanges may be folded into place either while the outer tray is inverted or after the outer tray has been turned upright to invert the inner tray. Where the completion of the carton is automatic, it is usually preferable to fold the end wall liner flaps 45 into locked position while the outer tray is still inverted.

The package thus formed is substantially tamper-pnoof,

for in order to open the package without injury to the outer tray, it is necessary to hold both side wall flanges against the side walls to swing the end wall lining flanges out of locking position and to then remove the plastic inner tray. However, the contents may be readily removed by inverting the outer package so that the inner package is upright and tearing two or more corners of the outer tray so that the outer tray may be lifted out of engagement with the inner tray. The inner tray then forms a receptacle for the contents and hold the contents assembled until they are used.

FIGURES 12-15 of the drawings disclose another form of construction which is very similar to the constructions previously described. The package C which is de scribed in these figures is similar to the package A with the exception of the fact that end wall liner flanges are provided on the end walls to supplement the side wall liner flanges disclosed in the package A. Furthermore,

1 the package C is virtually identical with the package A which has been described with the exception of the fact that the end wall liner flanges are considerably shorter. In other Words, the inner inverted tray is held in place by four liner flanges which may be of greater length than the distance between the upper edges of the end walls and the walls of the inverted tray.

As indicated in FIGURE 15 of the drawings, the outside tray includes a bottom panel 49 which is foldably connected along parallel fold lines 50 to side wall panels 51. The side wall panels 51 are foldably connected at their upper edges along fold lines 52 to side wall liner flanges 53. The ends of the bottom panel 49 are connected along fold lines 54 which intersect the fold lines 50 at right angles to end walls 55. The end walls 55 are connected along their upper edges 56 by fold lines to end wall liner panels 57.

In this construction, the side walls 53 may be of trapezoidal shape with the outer edges 59 somewhat narrower than the fold lines 52, the edges 59 being of a length substantially equal to the length of the side walls of the inner tray. The end walls 57 may also be of trapezoidal shape having their outer edges 60 narrower than the width of the fold lines 56 in approximately the same width as the end walls of the inner tray.

The inner tray 61 is virtually identical with the inner inverted tray previously described. The inner tray 61 includes a base panel 62 connected by slightly inclined side walls 63 and slightly inclined end walls 64 to a peripheral coplanar marginal flange 65. In this structure, the flange 65 fits within the side and end walls of the outer container when they are erected.

Locking tongues 66 are hingedly connected to the ends of the end walls 55, and these locking tongues are engageable into locking slots 67 in the side walls 51. Thus in this form of construction, the side and end walls are held in erect condition by the locking tongues rather than by adhesively connected corner flaps of the type shown in the previous form of construction.

With the form of construction illustrated in FIGURES 12-15, the outer tray may be formed by automatic equipment having the side and end walls at right angles to the bottom panel, and having the side and end wall liner flanges in the same plane as the walls to which they are attached. The side and end walls may be folded inwardly, and the tray thus formed may be inverted and forced downwardly over the inverted filled inner tray 61. In

this construction, the length of the side wall flanges 53 is greater than the distance between the upper edges of the side walls 51 and the side walls of the inner inverted tray. Furthermore, as contrasted with the package B, the end wall liner flanges 57 are also of greater length than the distance between the upper edges of the end walls 55 and the end walls 64 of the inner tray. Thus with this construction, it is not necessary that the end wall liner flanges be locked in position by the ends of the side wall liner flanges as in the package A.

In accordance with the patent statutes, the principles of construction and operation of this improvement in Display Carton have been described, and while an endeavor has been made to set forth the best embodiment thereof, it should be understood that changes may be made within the scope of the following claims without departing from the spirit of the invention.

I claim:

1. A display carton including a tray having a base panel and a series of wall panels encircling said base panel and extending at substantially right angles thereto, an inner receptacle including an inverted tray having coplanar marginal flanges adapted to fit snugly within the wall panels in face contact with said base panel, and locking flanges hinged to the marginal upper edges of certain of said wall panels and overlying said marginal flanges to hold said inner receptacle in position, the locking flanges being wider than the distance between the upper marginal edges of said certain wall panels and the walls of the inverted tray.

2. A display carton including a tray having a bottom panel and rectangularly arranged connectedside and end walls extending upwardly therefrom, an inner receptacle including an inverted tray having marginal outwardly projecting flanges fitting snugly within said side and end walls, at least two opposed of said Walls including flanges hinged to the upper edges thereof and extending inwardly and downwardly toward said bottom panel, the free ends of said flanges engaging over the marginal flanges of said inner receptacle, the flanges on the upper edges of said two walls being wider than the distance between said upper edges and the walls of said inverted tray.

3. The structure of claim 2 and in which said two opposed walls are said side walls.

4. A display carton including a tray having a base panel and rectangularly arranged connected side and end walls extending from the edges thereof at generally right angles thereto, an inner receptacle including a plurality of inverted tray-like compartments encircled by a planar marginal flange and separated by a connecting member coplanar with said marginal flange, said marginal flange fitting snugly within the walls of said tray,- and flanges on two opposed of said walls extending inwardly and toward said base panel to overlie said marginal flange to hold the same in face contact with said base panel, the flanges on said two opposed walls being wider than the distance between the connection between said flanges and said two opposed walls and the walls of said compartments.

5. The structure of claim 4 and in which said flanges are hinged to said side walls.

6. The structure of claim 4 and including a projecting member on said connecting member extending beyond the plane of said marginal flange, and said base panel having an aperture therethrough through which said projection extends.

7. The structure of claim 6 and in which said projection comprises a transversely extending rib.

8. The structure of claim 4 and in which the bases of said compartments are substantially on the plane of the edges of said side and end walls.

9. A display carton comprising an outer tray including a base panel and pairs of side and end wall panels encircling said base panels and extending upwardly therefrom at substantially right angles thereto, an inner receptacle comprising an inverted tray having side and end walls and coplanar marginal flanges on at least two opposed of said walls adapted to fit snugly between an opposed pair of wall panels of said outer tray in face contact with said base panel, and locking flanges hinged to the marginal upper edges of said opposed pair of wall panels and overlying said marginal flanges to hold the inner receptacle in position, said locking flanges being of substantially no greater width than the side wall panels to which they are hinged and being wider than the dis tance between the marginal edges of said opposed pair of wall panels and the walls of said inverted tray.

10. A display carton comprising an outer tray including a base panel and pairs of side and end. wall panels encircling said base panel and extending upwardly therefrom at substantially right angles thereto, an inner receptacle comprising an inverted tray having side and end walls and coplanar marginal flanges on said side and end Walls adapted to engage said base panel of the outer tray in face contact, said flanges on said side walls being adapted to fit snugly between said side wall panels of said outer tray, locking flanges hinged to the marginal upper edges of said side wall panels and overlying said marginal flanges on said side walls of said inner receptacle to hold said inner receptacle in position, said locking flanges being wider thanthe distance between the upper marginal edges of said side wall panels and the side walls of the inverted tray, end wall flanges hinged to the marginal upper edges of said end wall panels of said outer-tray and adapted to overlie the marginal end wall flanges of said inner receptacle.

11. The structure of claim 10 and in which said locking flanges include tapered end potrions, and in which said end walls flanges of said outer tray are engaged. beneath said tapered end portions and held in folded position thereby.

12. The structure of claim It) and in which said locking flaps are tapered from the ends of the fold lines connecting the locking flaps to the side walls to points on the edges of the flanges spaced apart a distance substantially equal to the length of the-side walls of the inner receptacle at their juncture with said marginal flanges, said end wall flanges of the outer tray engaging beneath said tapered locking flange edges.

13. The structure of claim 11 and in which the end wall flanges connected to the'end walls of the outer tray are narrower in width than the distance between the upper edges of the end walls of the outer tray and the end walls of the inner receptacle.

14. The structure of claim 12 and in which the end wall flanges connected to the end walls of the outer tray are narrower in width than the distance between the upper edges of the end Walls of the outer tray and the end walls of the inner receptacle.

15. A display carton comprising an outer tray including a base panel and pairs of side and end wall panels encircling said base panels and extending upwardly therefrom at substantially right angles thereto, an inner receptacle comprising an inverted tray having side and end walls and coplanar marginal flanges on said side and end walls adapted to engage said base panel of the outer tray in face contact, said flanges on said side walls being adapted to fit snugly between said side wall panels of said outer tray, locking flanges hinged to the marginal upper edges of said side wall panels and overlying said marginal flanges on said side walls of said inner receptacle to hold said inner receptatcle in position, said locking flanges being wider than the distance between the upper marginal edges of said side wall panels and the side Walls of the inverted tray, end wall flages hinged to the marginal upper edges of said end wall panels of said outer tray and adapted to overlie the marginal end wall flanges of said inner receptacle, said locking flanges on said end wall panels being longer than the distance between the upper edges of said end walls and the end walls of said inner receptacle.

References Cited by the Examiner UNITED STATES PATENTS 2,724,542 11/1955 Nemoede 229-34 3,029,936 4/1962 Graber 206-4531 X 3,116,825 1/1964 Thomas 206-4519 THERON E. CONDON, Primary Examiner.

W. T. DIXSON, Assistant Examiner.

Claims

1. A DISPLAY CARTON INCLUDING A TRAY HAVING A BASE PANEL AND A SERIES OF WALL PANELS ENCIRCLING SAID BASE PANEL AND EXTENDING AT SUBSTANTIALLY RIGHT ANGLES THEREO, AN INNER RECEPTACLE INCLUDING AN INVERTED TRAY HAVING COPLANAR MARGINAL FLANGES ADAPTED TO FIT SNUGLY WITHIN THE WALL PANELS IN FACE CONTACT WITH SAID BASE PANEL, AND LOCKING FLANGES HINGED TO THE MARGINAL UPPER EDGES OF CERTAIN OF SAID WALL PANELS AND OVERLYING SAID MARGINAL FLANGES TO HOLD SAID INNER RECEPTACLE IN POSITION, THE LOCKING FLANGES BEING WIDER THAN THE DISTANCE BETWEEN THE UPPER MARGINAL EDGES OF SAID CERTAIN WALL PANELS AND THE WALLS OF THE INVERTED TRAY.