US3246827A

US3246827A - One piece egg carton

Info

Publication number: US3246827A
Application number: US370435A
Authority: US
Inventors: Richard T Walter
Original assignee: Container Corp
Current assignee: Container Corp; Smurfit Kappa Packaging Corp
Priority date: 1964-05-27
Filing date: 1964-05-27
Publication date: 1966-04-19
Anticipated expiration: 1983-04-19
Also published as: DE1909283U

Description

' April 19, 1966 R. T. WALTER ONE PIECE EGG CARTON 5 Sheets-Sheet 1 Filed May 2'7, 1964 April 1966 RT. WALTER ONE PIECE EGG CARTON Filed May 27, 1964 S Sheets-Sheet 2 April 19, T WALTER ONE PIECE EGG CARTON 5 Sheets-Sheet 5 Filed May 2'7, 1964 T %w MZ I m a m A BY Mada 1%) United States Patent 3,246,827 ONE PIECE EGG CARTON Richard T. Walter, Norristown, Pa., assignor to Container Corporation of America, Chicago, 11]., a corporation of Delaware Filed May 27, 1964, Ser. No. 370,435 9 Claims. (Cl. 229-28) The present invention relates to foldable paperboard cartons and more particularly to cartons for retention of eggs.

Among the important objects of the present invention are to provide a strong, crush resistant carton formed from a single blank to alford a maximum degree of protection to its contents for a minimum area of paperboard employed; to provide a form of cellular carton that will give adequate protection for eggs or other fragile articles carried thereby without the use of a paperboard cover panel extending over the top of the carton; and to provide a carton as described having inclined outer side walls and with a top construction to support a superposed filled carton to insure good stacking qualities.

A further object of the invention is to provide a onepiece, cellular carton in which cross panels forming the transverse cellular walls are located centrally of the carton blank and the parts forming longitudinal panels are formed at the outer edge portions of the blank to be folded inwardly and upwardly and brought into locking relation with the cross panels, there being upwardly and inwardly sloping bottom panels to support the eggs at points above the outer lower edges of the carton and there being foot tabs formed on the longitudinal panels the lower edges of which are aligned with the outer lower edges of the carton to support the carton centrally, whereby the weight of the carton contents is distributed relatively uniformly over the entire bottom structure of the carton.

A further object of the invention is to provide an improved form of one-piece, cellular carton which includes integral end-s panels together with locking means to hold the ends in place, such end structure providing both a pleasing finished appearance to the carton ends and means for materially strengthening the ends of the carton.

A further object of the invention is to provide a four- Walled, cellular carton for fragile articles such as eggs, such carton having an open top and having side walls with portions thereof cut away adjacent the open cells of the carton, the carton being overwrapped with a shrink film envelope, the portions of the film over the cells being depressed partially below the general level of the carton walls, whereby the film portions over the cells will tend to contact the contained articles and hold them below the general level of the cell walls.

A still further object of the invention is to provide a one-piece, cellular carton that is particularly adaptable to be set up from its blank form by machine operation. 1

Additional and more specific objects and advantages of the invention will become apparent as the description proceeds.

In the drawings FIGURE 1 is a perspective view of a carton made in accordance with the present invention showing it in set up form, ready to receive its contents;

FIGURE 2 is a plan view of the carton;

FIGURE 3 is an end view;

FIGURE 4 is a bottom plan view;

FIGURE 5 is a vertical sectional view taken along line 55 of FIGURE 2;

FIGURES 6, 7 and 8 are transverse sectional views taken along lines 66, 77 and 88 respectively of FIGURE 2;

"ice

FIGURE 9 is a sectional view similar to FIGURE 6 but showing eggs in place within the carton;

FIGURE 10 is a plan View of the carton blank; and

FIGURE 11 is a perspective view on a reduced scale showing a carton having a shrink film overwrap placed about such carton.

The carton of the present invention is well adapted for use with a shrink-film overwrap, such as disclosed in applicants copending application Serial No. 330,680, filed December 16, 1963.

Referring more particularly to FIGURE 10 showing the carton blank, the carton comprises two elongated side wall panels 1, 1 to which are hingedly connected

bottom wall panels

2, 2 along

fold lines

3, 3. Longitudinal

center partition panels

4, 4 are hingedly carried on the outer edges of the bottom panels along

fold lines

5, 5.

Transverse partition panels, six being shown in the present instance, are hingedly arranged between the side walls so that they may be swung to positions at right angles to the planes of the side walls. These partition panels are indicated at 6a, 6a, 6b, 6b and 6c, 60 and they are arranged symmetrically so that the three partitions on each side of the mid-portion of the carton may swing downwardly and inwardly toward the mid-portion to their operative positions.

Partitions 6a are hinged along

fold lines

7, 7 to a relatively narrow strip of paperboard material 8. Extended center portions 811, 8a may be formed, if desired, on the strip 8 serving as space to receive printed matter or to give the carton a pleasing appearance. The ends of strip 8 are hingedly connected to the side walls 1, 1 along

fold lines

9, 9.

The end portions of each of the transverse partitions are connected to the side walls by means of gusset sections 10 at the ends of the partitions. These gusset sections are formed from the material of the side walls and are each defined by a fold line 11 and a cut or slit 12, and by a second fold line 13. To facilitate folding of the paperboard certain of the fold lines herein shown are formed partially by slits.

Transverse partitions

6b and 6c are preferably connected additionally to the carton side walls by small [

gusset sections

15, 15. These are formed by hinge or fold lines 16, aligned with fold lines 9, and additional hinge or fold lines 17. The gussets 15 are separated from the adjacent non-connected partition by a slit 12a forming an extension of slit 12. Thus, as best shown in FIGURE 1, the gussets 15 form hinged connections between the upper edges of side walls 1 and the upper edges of the downwardly folded transverse panels.

After the transverse partition panels have been brought to their vertical positions they are held while the bottom panels 2 and center partitions 4 are brought into position. The center partitions are constructed so that they may be brought into interfitting and interlocked relation with the transverse partitions. For this purpose the center positions are formed along their edges with inwardly extending V-

shaped cuts

19, 19. Communicating with each of these cuts are

slits

20, 20 which may be approximately aligned with one side of the V-shaped cut. At the inner end of each slit 20 is a die cut opening 21, indicated as generally circular, although the particular shape of the opening may be varied.

The V-shaped cuts 19, the slits 20 and the openings 21 form at one side thereof locking elements having

shoulder surfaces

22, 22 which extend approximately parallel with the outer edges of the

partition panels

4, 4.

Centrally of the center partitions are V-shaped cuts formed by

edges

23, 23 and the

tapered sides

24, 24 of narrow tongue or

tab elements

25, 25.

The cut edges 23 and the joined cuts and slits 19 and 20 thus form a series of

sub-partition sections

26, 27

and 28- on each side of the mid-portion of the center partitions 4 which, together with the transverse partitions make up the individual cells of the carton.

For the purpose of locking the parts of the center partitions with the transverse partitions, each of the transverse partitions is formed at its lower edge with inverted V-shaped cuts 39, 30 extending in the present instance about one-third of the width of the transverse partition. These

cuts

30, 30 are spaced to form between them a spacing tab 31. Spaced inwardly of the inverted V-shaped cuts 30 and aligned with the spacing tabs 31 of

transverse partitions

6b and 6c are die-

cut openings

32, 32 each having a straight portion 33 forming a locking shoulder.

When the carton has been partially formed by bringing the side walls and the transverse partitions to upright position the bottom panels 2 and center partition panels 4 are swung inwardly toward each other and the V-

shaped cuts

19 and 23 are brought into cross wise registration with the respective V-

shaped cuts

30, 30. By forcing the center partitions against the edges of the transverse partitions the latter are caused to enter the respective slits 2t), 20 and the slits a defining the sides of the tabs 25.

After the center partitions have been brought to their operative positions the

shoulder surfaces

22, 22 of the die-

cut openings

21, 21 will snap into engagement with the locking shoulder portions 33 of the die-cut openings 32, thus holding the center partitions firmly locked tothe transverse partitions. Additionally, the

tabs

25, 25 will be brought up to fit snugly edgewise between the two middle

transverse partitions

6a, 6a.

For the purpose of providing for relatively uniform distribution of the weight of the carton contents while the carton is resting on a supporting surface there are provided support means on the lower edges of the center partitions. As shown in FIGURE 10 the fold line 5 between the center partitions 4 and the bottom panels 2 are interrupted at locations symmetrically below the

subsections

26, 27 and 28 of the center partitions. A series of U-shape-d die-cut openings 34 are formed in the bottom panel 2 spaced along the fold line 5. Within these openings are formed a series of foot tabs 35, these tabs being arranged to project into the openings 34 at the interrupted places in the fold line. Thus the foot tabs 35 extend rigidly from the lower edges of the

sub-sections

26, 27 and 28.

As indicated in FIGURE 9 in certain cases the egg contained in the individual cells may be received partially Within the U-shaped openings 34. Cushioning slits 36 may be formed in the bottom panel 2 disposed between the openings 34 and the fold line 3 along which panel 2 is hinged to its attached side wall 1. It may also be noted that by upward pressure of a persons finger through the opening 34 an egg may be raised upward in its cell so that the upper portion of the egg may readily be grasped to remove it from the carton.

Cushioning slits, indicated at 37, 37 are preferably formed in the

sub-sections

26, 27 and 28 of the center partitions. Similarly,

cushioning slits

38, 38 are preferably formed in the two middle

transverse partitions

6a, 6a.

It is to be noted that the rigid tabs 31 are disposed between the two center partition panels and are effective in holding these panels separate-d. See FIGURES 6, 8 and 9.

The end closure construction of the carton will now be described. Downwardly

swingable end panels

40, 40 are hingedly connected to the top edges of the side panels by small

triangular gussets

15a, 15a which are similar to

gussets

15, 15. lnwardly

swingable extensions

41, 41 are hingedly carried along

fold lines

42, 42 at the respective ends of the side walls 1, 1. The extensions 41 are preferably formed with lower inclined edges, as seen in FIGURE 7, approximately conforming to the upward and inward inclination of the bottom panels 2 when in final operative position.

The inclined edges of the end panels 40 are connected to the adjacent edges of extensions 41 by means of gusset sections 43 hinged to such parts along

fold lines

44 and 45. In bringing the end closure parts to closed position, the extensions 41 will first be started to swing inwardly and simultaneously the gussets will be folded to lie between extensions 41 and end panel 40 as such end panel is being brought to closure forming position. Thus the extensions and the end panel 4i lie in flat relation with respect to each other with the gussets in between them.

The end panels 4% are tapered toward their lower edges and are preferably formed with two spaced

notches

46, 46. Locking

tabs

47, 47 on the ends of the center partition panels 4 are arranged to be engaged Within these notches, such tabs bearing on the outside surface of the end panel 40 to retain it locked in closed position. The side wall extensions 41 and the end panels 44 are brought to their vertical, closure forming position at substantially the same time as the transverse panels are swung to their vertical positions and While such end closure panels and transverse partitions are held in their operative positions the bottom panels and center partitions are moved to final positions as above described. At the same time that the center partitions reach their locking engagement with the transverse partitions the

tabs

47, 47 will be brought into locking engagement within the notches of the end panels. The carton is then ready to receive its contents.

By the provision of spaced center partitions in which cushioning slits have been formed it is feasible to place somewhat oversize eggs Within the cells of the carton without likelihood that the eggs in adjacent cells will contact oppositely against the same partition wall and become broken. Three oversize eggs could be placed in a row tending to press toward the mid-portion of the carton and their cumulative effect would cause one of the transverse panels 611 to bulge toward the other without undue risk because of the spacing between the midpanels 6a, 6a.

After the contents have been placed within the carton it is desirable to enclose the filled carton within a plastic shrink film wrapper such as shown in the copending application referred to above. Due to the notches formed in the side walls by utilizing these parts for the gusset connections, the film overwrap 50 becomes depressed into the spaces above the eggs in the individual cells and the film will thus come into firm contact with the eggs and tend to hold their upper surfaces below the top edges of the carton side walls as well as below the tops of the transverse partitions. This tends to assure that articles that might 'be placed on top of a filled egg carton will not cause the eggs to be broken because the tops of the walls and partitions will protect them.

While the present description sets forth a preferred form of the invention, numerous changes may be made in the construction as disclosed Without departing from the spirit of the invention, and it is therefore desired that the present disclosure be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

I claim:

1. A one-piece, cellular carton for eggs and other fragile articles, said carton comprising:

(a) elongated side walls separated to provide space for transversely extending partition panels and bottom walls,

(b) plurality of spaced vertically positioned, transverse partition panels extending between said side walls,

(c) means hingedly connecting respective upper portions of said transverse partition panels with adjacent upper portions of said side walls,

(d) the lower, central portion of each transverse partition panel being formed with symmetrically disposed, inverted V-shaped, cut-out portions spaced apart to provide between them a downwardly directed, rigid spacing tab coplanar with its partition panel,

(e) a narrow, elongated bottom wall hinged to the respective lower edge of each side wall,

(f) elongated, generally rectangularly shaped longitudinal partition panels hinged to the respective free edges of the bottom walls, each longitudinal partition panel being formed on its outer free edge with a plurality of spaced, inwardly extending cuts, the spacing of said cuts conforming with the spacing of the transverse partition panels, and into which respective transverse partition panels are received.

(g) the fiat, outer vertical edges of the spacing tabs sloping downwardly and outwardly and serving to contact at spaced locations along the longitudinal partition panels and hold said longitudinal partition panels separated.

2. A one-piece, cellular carton for eggs and other fragile articles, said carton comprising:

(0) means hingedly connecting respective upper portions of said transverse partition panels with adjacent upper portions of said side walls,

(d) a narrow, elongated bottom wall hinged to the respective lower edge of each side wall,

(e) elongated, generally rectangularly shaped, center partition panels hinged to the respective free edges of the bottom walls, each center partition being formed on its outer free edge with a plurality of spaced, inwardly extending cuts, the spacing of said cuts conforming with the spacing of the transverse partition panels, and intowhich respective transverse partition panels are received,

(f) said bottom walls each having a plurality of openings therein located symmetrically intermediate the transverse partition panels, whereby the lower end portion of an egg may rest partially in each open ing, said openings serving to admit the finger of the user, whereby the-eggs may readily be displaced upwardly, and wherein said bottom walls are upwardly and inwardly inclined toward the longitudinal center line of the carton, and in which a rigid tab, forming an extension of a portion of the longitudinal partition panel hinged to the bottom wall panel, is cut from the material removed from each of said openings, the lower endsof said tabs being extended downward to -a level'conforming with the lower edges of the side walls and serving as centrally located supports for the bottom panel.

3. A one-piece, cellular carton .for eggs and other fragile articles, said carton comprising (a) elongated side wall members'separated to provide space for transversely extending partition-forming members and bottom-forming members,

(b) the upper portions of the side walls having triangular gusset sectionsextending inwardly of the side wall edges and defined by a cut along one edge and a fold line along an adjacent edge,

(c) plurality of spaced vertically positioned,'transverse partition panels foldably connected at their opposite ends to the third side of the respective, oppositely located gusset sections on the side walls,

(d) additional triangular gusset sections connecting the respective top edges of the vertical panels with the adjacent top edge of the side wall panel,

(e) the lower, central portion of each transverse vertical partition panel being formed with symmetrically disposed, inverted V-shaped, cut-out portions spaced apart to provide between them a downwardly directed, rigid spacing tab coplanar with its vertical partition panel,

(f) a narrow, elongated bottom wall hinged to the respective lower edge of each side wall,

(g) elongated, generally rectangularly shaped, center partition panels hinged to the respective free edges of the bottom walls, each center partition being formed onits outer free edge with a plurality of spaced, inwardly extending, V-shaped cuts having slits communicating therewith at the apex of each V-cut, the spacing of said cuts conforming with the spacing of the transverse partition panels,

(h) each of such slits terminating in an undercut portion providing an overhanging shoulder extending approximately parallel with the outer free edge of the partition,

(i) each transverse, vertical panel being formed with a die-cut opening at a location spaced symmetrically above the downwardly extending spacing tab, each of 'said openings presenting an upwardly directed abutment surface against which the respective shoulders on the center partitions may engage with a snap action after the center partitions have been forced upwardly far enough for the material of the trans verse partition below such abutment surface to pass through the slit above the shoulder,

(j) the outer vertical edges of the spacing tabs serving to contact at spaced locations along the center partitions and hold said partitions separated.

4. A one-piece, cellular carton for eggs and other fragile articles, said carton comprising (a) two elongated side wall members separated to provide for transversely extending partitions and bottom-forming members,

(b) the upper portions of the side walls having triangular gusset sections extending inwardly of the side wall edges and defined by a cut along one edge and a fold along an adjacent edge,

(c) a plurality of vertically positioned, transverse partition panels foldably connected at their opposite ends to the third side of the respective, oppositely located gusset sections on the side walls,

(d) the lower, central portion of each transverse partition panel being formed with symmetrically dis posed cut-out portions of inverted V-shape and spaced apart to provide between them a downwardly directed, rigid spacing tab coplanar with its vertical partition panel,

(e) a narrow, elongated bottom wall hinged to the respective lower edges of the side walls,

(f) elongated, generally rectangularly shaped, center partition panels hinged to the respective free edges of the bottom walls, each center partition being formed on its outer free edge with a plurality of spaced, inwardly extending cuts conforming with the spacing of the transverse partition panels and into which the respective partition panels are received, the outer vertical edges of the spacing tabs serving to contact at spaced locations along the opposite center partition panels and hold them separated,

(g) a downwardly swingable end panel at each end of the carton extending between the ends of the side walls, triangular gusset sections connecting the lateral top portions of the end panels with the respective tops of the side walls, each of said end panels being generally triangular in form and having an upper side generally conformable with the level of the tops of-the transverse partition panels, and the other two sides being inclined symmetrically downward,

(h) and upwardly extending locking tabs on the ends of the center partition panels to engage the outer surface of each respective downwardly swingable end panel to hold same in vertical, end-forming position.

5. A one-piece, cellular carton for eggs and other fragile articles, said carton comprising (a) two elongated side wall members separated to provide for transversely extending partitions and hottom-forming members,

(b) the upper portions of the side walls having triangular gusset sections extending inwardly of the side wall edges and defined by a out along one edge and a fold along an adjacent edge,

(d) the lower, central portion of each transverse partition panel being formed with symmetrically disposed cut-out portions of inverted V-shape and spaced apart to provide between them a downwardly directed, rigid spacing tab coplanar with its vertical partition panel,

(e) a narrow, elongated bottom wall hinged to the respective lower edges of the side walls.

(g) a downwardly swingable end panel at each end of the carton extending between the ends of the side walls, triangular gusset sections connecting the lateral top portions of the end panels with the respective tops of the side walls, each of said end panels being generally triangular in form and having an upper side generally comformable with the level of the tops of the transverse partition panels, and the other two sides being inclined symmetrically downward,

(h) inwardly foldable extension panels hinged on the respective ends of each of the side walls, said panels each having an upper edge generally conforming with the upper side edge of the adjacent downwardly swingable end panels, a gusset fold section hingedly connecting each downwardly inclined edge of the downwardly swingable end panel with the top edge of the adjacent inwardly foldable extension panel,

(i) and upwardly extending locking tabs on the ends of the center partition members to engage the outer surface of each respective downwardly swingable end panel to hold same in vertical, end-forming position.

6. A one-piece, cellular carton for eggs and other fragile articles, said carton comprising (a) two elongated side wall members separated to provide for transversely extending partitions and bottomforming members, I

(b) a plurality of spaced, vertically positioned, transverse partition panels extending between said side walls,

(c) means for hingedly connecting the respective top edges of the vertical panels with the adjacent top edge of the side walls,

(d) the lower, central portion of each of the transverse partition panels being formed with upwardly extending, cut-out portions,

(f) elongated, generally rectangularly shaped, center partition panels hinged to the respective free edges of the bottom walls,

(g) each center partition being formed on its outer free edge with a plurality of spaced, inwardly extending cuts conforming with the spacing of the transverse partition panels and into which cuts the individual transverse partition panels are received,

(h) a downwardly swingable end panel at each end of the carton and extending between the ends of the side walls,

(i) means for hingedly connecting the lateral top portions of the end panels with the respective tops of the side walls, each of said end panels having an upper side generally comforma-ble with the level of the tops of the transverse partition panels,

(j) inwardly foldable extension panels hinged on the respective ends of each of the side walls and folded to be disposed in closure forming position across the ends of the carton, said panels each having an upper edge generally conforming with the upper side edge of the adjacent downwardly swingable panel and being arranged to underlie such downwardly swingable end panel,

(k) and means on the ends of the center partition panels adapted to engage the outer surface of each respective downwardly swingable end panel to hold same in vertical, end-forming position.

'7. A one-piece, cellular carton for eggs and other fragile articles, said carton comprising (a) two elongated side wall members separated to provide for transversely extending partitions and bottomforming members,

(c) triangular gusset sections connecting the respective top edges of the vertical panels with the adjacent top edge of the side walls,

((1) the lower, central portion of each of the transverse partition panels being formed with upwardly extending, cut-out portions,

(g) each center partition being formed on its outer free edge with a plurality of spaced, inwardly extending cuts conforming with the spacing of the transverse partition panels, and into which cuts the individual transverse partition panels are received,

(i) triangular gusset sections hingedly connecting the lateral top positions of the end panels with the respective tops of the side walls, each of said end panels being generally triangular in form and having an upper side generally conformabie with the level of the tops of the transverse partition panels, and the other two sides being inclined symmetrically downward,

(j) inwardly foldable extension panels hinged on the respective ends of each of the side walls and folded to be disposed in closure forming position across the ends of the carton, said panels each having an upper edge generally conforming with the upper side edge of the adjacent downwardly swingable panel and being arranged to underlie such downwardly swingable end panel (k) a gusset fold section hingedly connecting each downwardly inclined edge of the downwardly swingable end panel with the top edge of the adjacent inwardly foldable extensionpanel,

(l) and upwardly extending locking tabs on the ends of the center partition panels to engage the outer surface of each respective downwardly swingable end panel to hold same in vertical, end-forming position.

8. A one-piece, cellular carton for eggs and other fragile 7 articles, said carton comprising (a) two elongated side wall members separated to provide for transversely extending partitions and bottomforming members,

(b) the upper portions of the side walls having triangular gusset sections extending inwardly of the side wall edges and defined by a cut along one edge and a fold line along an adjacent edge,

(e) a plurality of spaced, vertically positioned, transverse partition panels foldably connected at their opposite ends to the third side of the respective, oppositely located gusset sections on the side walls,

(d) said gusset sections lying flat against their respective attached side walls to reinforce the same,

(e) the transverse partitions at opposite end sections of the carton beginning at the mid-portion being hingedly connected to the side walls by their gusset sections to swing to their partition forming position in opposite directions downwardly and inwardly toward such mid-portion,

(f) the two adjacent transverse partition panels at the mid-portion of the carton being closely spaced,

(g) said two partition panels being hinged to a narrow panel extending transversely of the carton and disposed flatwise in the plane of the upper edges of the side walls,

(h) a narrow, elongated bottom wall panel hinged to the lower edge of each side wall,

(i) elongated, generally rectangularly shaped, center partition panels hinged to the respective free edges of the bottom wall panels,

(3') each center partition being formed on its outer free edge with a plurality of spaced, inwardly extending cuts conforming with the spacing of the transverse partition panels and into which the respective partition panels are received, each of said center partitions having centrally thereof an extended, narrow tab closely interfitting between the closely spaced, transverse partitions at the mid-portion of the carton.

9. A carton as defined in claim 8 in which the two 10 closely spaced transverse partitions at the mid-portion of the carton are formed with cushioning slits located intermediate the center partition panels and the side walls.

References Cited by the Examiner UNITED STATES PATENTS 1,962,296 6/1934 Burger 22929 1,990,336 2/1935 Levkotf 229-29 2,205,157 6/ 1940 Schrell 22928 2,321,209 6/ 1943 Holwick 229-29 2,980,245 4/ 1961 Stoker 2292.5 3,104,794 9/ 1963 Sheldon-Williams 229-28 FOREIGN PATENTS 50,594 8/1935 Denmark. 343,285 1/1960 Germany. 357,672 11/1961 Germany. 804,755 11/1958 Great Britain. 867,444 5/1961 Great Britain.

30 JOSEPH R. LECLAIR, Primary Examiner.

Claims

1. A ONE-PIECE, CELLULAR CARTON FOR EGGS AND OTHER FRAGILE ARTICLES, SAID CARTON COMPRISING: (A) ELONGATED SIDE WALLS SEPARATED TO PROVIDE SPACE FOR TRANSVERSELY EXTENDING PARTITION PANELS AND BOTTOM WALLS, (B) PLURALITY OF SPACED VERTICALLY POSITIONED, TRANSVERSE PARTITION PANELS EXTENDING BETWEEN SAID SIDE WALLS, (C) MEANS HINGEDLY CONNECTING RESPECTIVE UPPER PORTIONS OF SAID TRANSVERSE PARTITION PANELS WITH ADJACENT UPPER PORTIONS OF SAID SIDE WALLS, (D) THE LOWER, CENTRAL PORTION OF EACH TRANSVERSE PARTITION PANEL BEING FORMED WITH SYMMETRICALLY DISPOSED, INVERTED V-SHAPED, CUT-OUT PORTIONS SPACED APART TO PROVIDE BETWEEN THEM A DOWNWARDLY DIRECTED, RIGID SPACING TAB COPLANAR WITH ITS PARTITION PANEL, (E) A NARROW, ELONGATED BOTTOM WALL HINGED TO THE RESPECTIVE LOWER EDGE OF EACH SIDE WALL, (F) ELONGATED, GENERALLY RECTANGULARLY SHAPED LONGITUDINAL PARTITION PANELS HINGED TO THE RESPECTIVE FREE