US3157346A

US3157346A - Stacking paperboard lug box

Info

Publication number: US3157346A
Application number: US205446A
Authority: US
Inventors: Hamilton Joseph Portola
Original assignee: American Box Corp
Current assignee: American Box Corp
Priority date: 1962-06-26
Filing date: 1962-06-26
Publication date: 1964-11-17
Anticipated expiration: 1981-11-17

Description

Nov. 17, 1964 J. P. HAMILTON STACKING PAPERBOARD LUG BOX 3 Sheets-Sheet 1 Filed June 26, 1962 INVENTOR. v JQSEPH PO/QTOLA HAMILTON ATTORNEYS Nov. 17, 1964 J. P. HAMILTON STACKING PAPERBOARD LUG BOX 3 Sheets-Sheet 2 Filed June 26, 1962 FIG 3 INVEN TOR.

JOSEPH POI? TOLA H4M/L T ON BY ATTORNEYS Nov. '17, 1964 J. P. HAMILTON STACKING PAPERBOARD LUG BOX 3 Sheets-Sheet 3 Filed June 26, 1962 INVENTOR.

JOSEPH PORTOLA HAM/L TON 9 1.. nuli 1- United States Patent G 3,157,346 STACKING PAPERBQARD LUG BGX Joseph Portola Hamilton, Emeryville, Calii'l, assignor to American Box Corporation of California, San Francisco, Califi, a corporation of California Filed June 26, 1962, Ser. No. 285,446 4 Claims. (Cl. 229-23) This invention relates to a fiberboard lug box and the like, and has for one of its objects the provision of a fiberboard box that is adapted to better resist collapse than heretofore, under compression, such as occurs in the lower boxes of a stack of loaded boxes.

Another object of the invention is the provision of a fiberboard box that is adapted to be shipped flat, or in a collapsed position, and later set up for use, and which box is provided with reinforced end walls and means for holding superposed boxes against shifting laterally relative to each other in any direction.

An additional object of the invention is the provision of a foldable fiberboard box having a structure that provides for better ventilation of the interior of superposed boxes than heretofore.

Still further objects of the invention are the provision of; improved locking means for locking the boxes in setup position; improved end wall structure providing for greater strength than heretofore; a more economically made structure in a lug box having the desired strength for withstanding collapse under the compression force of loaded boxes supported thereon when subjected to changes in normal atmospheric humidity.

Other objects and advantages will appear in the description and drawings.

In the drawings, FIG. 1 is a plan view of a blank from which one portion of the box is to be formed.

FIG. 2 is a fragmentary plan view of one end portion of a blank that is similar to that of FIG. 1 but modified along opposite end portions. The portion shown in FIG. 2 corresponds in position to the lower portion of the blank of FIG. 1 and the upper end of the blank of FIG. 2, if shown, would have the same structure as seen in FIG. 2.

FIG. 3 is a plan view of a second blank adapted to be used with the blank of FIG. 1 to overlie the latter centrally thereof.

FIG. 4 is a fragmentary plan view of one end portion of a blank that is similar to that of FIG. 3 but modified for use with the modified blank of FIG. 2.

FIG. 5 is an isometric view of the blanks of FIGS. 1 and 3 secured together preparatory to forming the box, with several portions of the assembly partially folded upwardly.

FIG. 6 is an isometric view of the blanks of FIGS. 1-

and 3 substantially folded to form the box, but with certain parts still extended so as to reveal interior structure.

FIG. 7 is an enlarged cross sectional view taken along line 7-7 of FIG. 6.

FIG. *8 is an isometric view that is similar to that of FIG. 6 but which view is of the modified form of the invention that is produced from the blanks of FIGS. 2 and 4. The view is partly broken away to adapt it to the sheet.

In detail, referring to the blank of FIG. 1, this blank 3,157,346 Patented Nov. 17, 1964 Equally spaced from the pair of creases 1, at the sides thereof outwardly of the bottom panel 2, are folding creases 3 that are parallel with the creases 1, each crease 3 being relatively close to the crease 1 that is adjacent thereto. Thus a narrow panel 4 is disposed between each crease 1 and folding crease- 3 that is adjacent thereto.

These narrow panels 4 join the side walls of the box to the bottom panel 2, hence they extend longitudinally of the box, and parallel opposite free end edges 5 extend between the ends of the creases 3 at the corresponding ends of said creases 3,, which free end edges define the ends of the bottom panel 2.

Outwardly of the pair of creases 3, and integral with the narrow panels 4 are corresponding side wall panels 6.

Folding creases 7 form the junctures between the outer side wall panels 6, and top panels 8, the latter being alike, and in the finished box these will extend over the bottom wall 2 a distance equal to their respective widths.

The panels 8 terminate in outer free edges 9 that may be parallel with creases 7, or scolloped or of any other desired contour, and these free edges define end edges of the central portion of the blank.

Referring to the panels 6, it is seen that these panels are integrally connected at their ends with end sections generally designated 11 along folding creases 10.

These end sections 11 are alike, and each comprises three

panels

13, 14, 15 in a row, "in which the panel 14 at each end of each outer side wall panel 6 is the central panel in each row.

There are four separate sections 11, as seen in FIG. 1. The panels 13 are like each other, and each of the panels 15 are alike. These will later be described more in detail.

In the blank of FIG. 1 the panels 13 are integral with the panels 14 along folding creases 16 that, in turn, are parallel with the

creases

1, 3 and each crease 16 is in outward projection of and in alignment with a substantial medial line through each narrow panel 4.

The panels 15 are outwardly of the opposite ends of each ofthe top panels 8, and are separated from said top panels 8 by cuts 17 that are in alignment with the free end edges 5 of the bottom panel 2. At this point it may be noted that the folding creases 10 at the ends of the side wall panels 6 are slightly offset toward each other relative to the free end edges 5 and cuts 17. The reason for this will appear later on.

A pair of parallel relatively closely spaced folding creases 18 that are parallel with the folding crease 16 in the same section define two of the edges of a narrow strip 19 that joins the

adjacent panels

14, 15 of each section 11'. These creases 18 are equally spaced at opposite sides of a line in extension of each crease 7 that is at the juncture between each side wall panel 6 and the top panel 8 adjoining it.

The outer free edges 20 that are along the panels 13-15 of each set 9 are straight and uninterrupted. However, the adjacent panels 13 at the ends of the bottom panel 2, and along free end edges 5 are spaced apart, and terminate in free edges 23 that are at right angles to edges 20, and along each edge 23 a rectangular tab 24 projects into the space between the adjacent panels 13, which tabs are equally spaced from the edges 5 at each end of bottom wall 2, and each such tab is preferably closer to edge 5 than to the outer edge 20 of the sections 13-15.

The crease 18 ofeach pair thereof that is closest to the central panel 14 of each section 11 does not extend uninterruptedly between cut 17 and the outer free edge 20 of each section, but is interrupted by cuts that form an elongated rectangular tab 25, which tab extends across the adjacent crease 18 and into the adjacent panel 15 to a point about midway between the panel 15 and its free 3 edge 26 that is substantially in alignment with the free edge 9 of the blank.

Each tab 25 extends at a right angle to the creases 18 and each tab is at the same distance from the cut 17 that is adjacent thereto as each tab 24 is distant from the adjacent free end edge of the bottom panel 2. Also the width of each tab 25 is substantially the same as the width of each tab 24 in the same dimension, or in the same direction as edge 23 or creases 18.

Offset relative to each pair of folding creases 18 in a direction toward the outer free end of each tab 25, is a pair of parallel, closely spaced folding creases 27, which creases are parallel to creases 18 that are adjacent thereto.

The distance between each pair of creases 18 is such that the panel 13 will lie fiat between the

panels

14, 15 when each panel 13 is folded upwardly (as seen in FIG. 1), over and against the central panel 14, and panel 15 is then folded upwardly and over and against the panel 13. FIG. 5 shows two such sections, after folding, the section at the upper right hand corner being fiat with the bottom panel 2, the latter being covered in FIG. 5 by another blank, as will be described later on.

The distance between the edge 23 of each panel 13 and the crease 16 adjacent thereto, is substantially equal to the distance between creases 16, and the crease 18 nearest thereto, while the distance between crease 16 and the crease 17 in tab that is nearest thereto is substantially equal to the distance between the outer free end edge of tab 24 and the crease 16, therefore, when the panel 13 is folded against panel 14, the outer free end of tab 24 will be at the above-mentioned crease 27, and upon folding panel 15 over panel 13, the tab 25 will project beyond the narrow strip 19 between creases 18, yet the outer end portion of tab 25 beyond creases 47 may be folded over the projecting tab 24, as seen in FIG. 5.

Two elongated slots are formed along each crease 7. These are ventilation slots in the finished box, and one or more slots 31 are formed in each narrow panel 4 for the same purpose.

On each end of each top panel 8 an outwardly projecting tab 32 is formed. These tabs 32 each have one tapered edge 33 to facilitate their entry into slots that are provided in the blank of FIG. 3 that is part of the finished box when said blank is assembled with the blank of FIG. 1 to form the box. This will later be described. Each tab 32 extends into each top panel 8 a short distance, and the base edge of each tab is defined by a folding crease 34. Each tab 32 extends into each panel 15, and therefore interrupts the cut 17 that is between the top panel 8 and each panel 15.

A small triangular portion of the blank is stamped out at the end of each narrow panel 4, to form a triangular opening 35, having its base in extension of the free edge 5 of the bottom panel, and the apex of each opening 35 is on the line of each crease 16, and at the end of each such crease that is adjacent to each narrow panel 4. The reason for this opening is to enable the narrow panels 4 to extend slantingly upwardly when the box is formed so that the ventilating openings 31 will not be blocked off when the boxes are in adjoining stacks. This is a highly desirable feature in a box of this type.

Along each of the free end edges 5 of the bottom wall or panel 2 is a pair of square, outwardly opening notches or recesses 36. These are equally spaced from the ends of creases 1, and will cooperate with certain structure in the panel of FIG. 3 when the latter is assembled with the panel of FIG. 1.

Also, along the edge 26 of each panel 15 is a relatively shallow square notch or outwardly opening recess 37 that is adapted to cooperate with the notch 36 that is nearest thereto and with structure in the panel of FIG. 3 when the box is assembled. Adjacent to each notch 37, each panel 15 is cut away to form a slanted edge 38 that is adapted to engage the upper surface of the narrow panel 4 when the box is set up with said narrow panel in an inclined position, as has already been mentioned, and an opening 39 is formed along each crease 16 adjacent to each opening 35, which opening extends into

panels

13, 14.

Referring to the blank of FIG. 3, this blank is elongated so as to extend across and over the bottom panel 2 of the blank of FIG. 1, and has a central portion 40 that is of the same width as the bottom panel 2, hence when the central portion 40 is positioned on the bottom panel 2 its free edges will be along and be parallel with the folding creases 1, to become the upper layer of the bottom of the carton, while panel 2 will be the lower layer.

Parallel folding creases 43 extend transversely across the panel of FIG. 3 and are spaced apart a distance substantially equal to the distance between the free end edge 5 of the bottom panel 2.

Outwardly of the pair of folding creases 43 are corresponding end portions each having a pair of relatively closely spaced folding creases 44 extending thereacross, which creases 44 are parallel with the crease 43 adjacent thereto. Each pair of creases 44 divides the end portion in which it is formed into a pair of substantially

oblong panels

45, 46, with the panel 45 being the one adjoining crease 43.

When the central panel 40 is secured on the bottom panel 2 of the blank of FIG. 1, the

panels

45, 46 will be folded to opposed relation along creases 44 and each panel 46 will become the inner layer of one of the end walls of the box, while the panel 45 will become the outer layer, and the narrow strip 47 between each pair of creases 44 will be the upper edge of one of said end walls.

The width of each panel 45 in the dimension of the width of the panel 40, which is transversely of the length of the latter, is slightly greater than the width of panel 40, and panel 45 is of the same width up to the folding crease 44that is remote from the central panel 40.

The width of each panel 46, in the dimension of the width .of the central panel 40 is slightly greater than the width of panel 45.

The outer free end edges of the main blank of FIG. 3 are the free longitudinally extending edges of the end panels 46, and are designated 48, and the outer corners of each panel 40 are cut off at 43 to have the same degree of inclination as the degree of inclination of the narrow panel 4 of the blank of FIG. 1 when the box is assembled. Also the corners of panel 45 at the ends of creases 43 in the blank of FIG. 3 are cut off at 50 at a similar angle.

A rectangular opening 53 is formed adjacent to each end of each crease 43, which openings extend across the creases and partly into panels 45 at one side of each crease, and partly into the central panel 40, with the major portion of each opening being in the central panel. These openings are equally spaced from the ends of the creases 43.

A pair of tabs 54 is formed in each of the narrow strips 47 between each pair of creases 44, with the base end of each tab integral with each panel 45 along the line of the crease 44 that defines the juncture between each panel 44 and each such strip 47. However, the tabs are not creased along the above-mentioned line of one of the creases 44, hence the latter creases are interrupted by the tabs. The remainder of tabs 54 are free from the portions 47 and the outer free edges of said tabs are slightly short of the openings that are cut in the blank to form the tabs, thereby leaving a slight slot 55 between the outer free edge of each tab and a line coincidental with the crease 44 that is remote from each panel 45.

The outer free edges 48 of the blank of FIG. 3 are formed with relatively slight outwardly projecting tabs 56 that are equally spaced from the ends of said edges 48.

The spacing between the openings 53 and between tabs 54 and tabs 55 is the same, and the pairs of said tabs and openings are aligned longitudinally of the blank of FIG. 3.

In forming the lug box, the central panel 40 of the blank of FIG. 3 is glued against the upper surface of the bottom panel 2 of FIG. 1 (FIG. 5) so that the free side edges of the central panel 40 will be substantially in registration with the folding creases 1 of the blank of FIG. 1, and so that the creases 43 of the panel of FIG. 3 will be substantially in registration with the free edges 5 of the blank of FIG. 1.

The

panels

13 and 15 of each section 11 are then folded in succession, over the panel 14 with the result that the notches 37 will be in registration with the openings 39 as seen in the upper right hand section 11 in FIG. 5.

The side panels or side walls 6 may then be swung upwardly to positions substantially at right angles to the bottom panel 2 about creases 1, and then the previously folded panels 13-15 are swung about creases 10 to positions over the central panel 10 and at right angles to the side walls 6.

The narrower widths of the side walls 6 between creases it than the width of the bottom panel 2 between cuts 17 will result in the assembled er prefolded panels 13-15 drawing the narrow panels 4 to upwardly inclined positions in which the slanted edges of openings 35 that are formed in

panels

13, 14, and which are in registration when the panels 13 are folded onto panels 14, will engage the upper surfaces of said narrow panels 4 when the assembled sections 11 are swung to positions over the central panel 44 After the folded sections 11 are swung to positions over the central bottom panel 40, the planes of the outer free surfaces of the panels 14 of sections 11 will be substan tially in registration with the folding creases 43. The right hand lower corner of FIG. 5 shows one of the sections 11 in a position preparatory to being swung upwardly and over the central bottom panel 40.

Either before or after the sections 11 are swung to positions over the central bottom panel 40 each of the tabs 25 on each panel 14 may be folded along creases 27 over the tab 24 that is adjacent thereto, since the tabs 24 will be in register with the portions of the tabs 25 that extend across the pairs of creases 18 when the panels 13, of each section 11 are folded over the panel 14 between them. The outer end of each tab 24 terminates at the crease lines 2'7 in the adjacent tab 25 to enable each tab 25 to fold over each tab 24.

It is pertinent to note that when each section 11 is swung over the central panel 40 the openings 53 will be in registration with the notches 37 formed in the free edges of the panels 15, and with the equivalent notches formed by openings 39 along creases 16. Also, when this is done, the portions of openings 53 that extend into the panels 46 will form downwardly opening recesses (FIG. 5) adjacent to each of the ends of the panels 46 along their lower edges.

The next step in forming the box is to swing the panels 45 upward and against the outer surfaces of the sections 11, which outer surfaces are at the outer sides of the panels 14 of said sections. The panels 46 are then swung over the upper edges of sections 11 and downwardly to lie against the inner surfaces of sections 11, which surfaces are one of the surfaces of the panels 15. In performing the foregoing step, the tabs 25, with the tabs 24 enclosed thereby, as indicated in FIG. 6, will enter and pass through the openings in which the tabs 54 are positioned, and the latter tabs will project upwardly alongside the tabs 25. At the same time the tabs 56 will spring into openings 53 to hold the panels 46 against the sections 11, with said sections disposed between

panels

45, 46. When the tabs 56 are sprung into the openings 53, they are quite firmly held so there is little, if any, chance for the panels 45 to be released accidentally. The free edges 48 of the panels 45 are snugly against the upper surface of the central panel 4! and the narrow strips 47 that are between

panels

45, 46 are snugly against the upper edges of the folded sections 11.

The box in this form will provide a satisfactory box, independently of the top panels 3 that are carried by the side walls 6, but these side walls contribute to greater rigidity by bending the tabs 32 to positions at right angles to the panels 8, and projecting toward each other when panels 8 are vertical, so that said tabs will enter the openings that interrupt the narrow strip 47 where tabs 51 are formed. When the top panels, which may be called closure flaps are folded downwardly they will extend over the upper open side of the box and tabs 32 and panels 3 will hold the upper portions of the panels 6 against any tendency to swing or bow outwardly relative to the contents of the box.

In stacking the boxes the upwardly extending projections formed by

tabs

24, 25, 54 will project into the openings 53 in the box thereabove, and the slanted panels 4 along the lower corners of the upper box will permit free ventilation to the upper box through openings 31, and also the fact that these panels 4 are inclined will present their blocking ventilation through the openings 30 in the lower box, or the box below the upper box.

Of material importance is also the fact that there are five layers of fiberboard in each of the end walls of each box (FIG. 7), and which layers extend to the corners of the box, where corrugated, double faced fiberboard is used, the corrugations in the layers of the sections 11 and in the

panels

45, 46 between which said sections are held, are vertical, hence present the maximum resistance to distortion or collapse against compression due to the loads in boxes superposed above others in a stack.

Where loaded boxes of the type described are held for a moderate length of time in a warehouse, and the fiberboard is not treated to resist adsorption of moisture from the atmosphere, the lower boxes Will not collapse.

Where boxes are to be held for relatively long periods of time, the structure of FIGS. 2, 4 and 8 may be used.

In this form of the invention, substantially the same blanks are employed as in FIGS. 1, 3, except that the sections 1.1 are cut off along parallel lines that are coincidental with the edges of

tabs

24, 25 that face away from the bottom panel 2, hence the same numbers used in describing the structures of the blanks of FIGS. 1 and 3 will apply to the blanks of FIGS. 2, 4 and to the box of FIG. 8, where the structures are identical.

The portions of

panels

13, 14 and 15 that remain in FIGS. 2 and 8 are numbered 113, 114 and 115 and after cutting off the

panels

13, 14, 15 of FIG. 1, as above described, the openings 39 in the blank of FIG. 1 become recesses 139 in FIG. 2.

With respect to the blank of FIG. 4-, this blank is identical with the blank of FIG. 3 except that a rectangular block of wood 100 is glued against the side of each panel 46 in a position to lie between the sections 111, which consist of

panels

113, 114, 115, when said sections are in folded relation as described with respect to the panels 13-15 of FIG. 1.

When said panels 113-115 are folded on each other in the same manner as described with respect to panels 13-15 of sections 11, it is apparent that the space between sections 111 (FIG. 8) will be substantially greater than the space between sections 1 (FIG. 6) hence the blocks 100 in FIGS. 4, 8 may be relatively long.

The thickness of each block 1% may be approximately the same as the thickness of the sections 111, but since the blocks will take the load of upper boxes in a stack, the boxes of the structure of FIGS. 2, 4 and 8 will retain their stability against collapse for an indefinite period of time.

The folding of the blanks of FIGS. 2, 4 to form the box of FIG. 8 is the same as the folding of the blanks of FIGS. 1, 3 to form the box of FIG. 6, hence the steps will not be repeated.

From the description of the boxes of FIGS. 6 and 8, it is seen that the boxes in a stack will be held in perfect vertical alignment to prevent upsetting of a stack due to inaccurate stacking. The projections formed by the

tabs

24, 25, 54 and openings 53 insure this result. In actual practice the panels 1315 and panels 113-115 are glued together, and when the tabs or projections 24 are enclosed by the tabs 25, they insure strong projections that will not be bent or torn, since each projection formed thereby consists of three layers of the fiberboard, to say nothing of the tabs 54 that are alongside tabs 25.

Being of two-piece construction, the present box can be laid out to use a minimum of material for applied application to a specific commodity and, if desired, the two portions can be of difierent board weights, for example, the blank of FIG. 1 could be of heavier weight than the blank of FIG. 3, in order to obtain the benefit of the strong sections 11 that are on the blank of FIG. 1. There are instances where a lighter weight blank of FIG. 3 may be used but such lighter weight would be inadequate to provide the strength required in the sections 11 and side walls.

The provision of

separate blanks

1 and 3, or 2 and 4, provides a box in which the length of the corrugations in the side and end walls are vertical, thus providing maximum resistance to compression in both end and side walls, and also the fact that the corrugations in the bottom layers extend, unbroken, at right angles to each other, insures against bottom sag under a load.

Furthermore, the employment of the separate blanks, as described, enables the manufacturer to imprint the blank of FIG. 1 as a stock item for all customers, to be held in stock, and the blanks of FIG. 3 could then be imprinted to customer orders. This would effect a substantial economy.

There are many other advantages to be derived from the two-piece construction, hence this structure is an important feature of the present invention.

I claim:

1. A lug box comprising:

(a) a pair of separate blanks of fiberboard, each having (b) substantially corresponding, horizontally disposed,

rectangular central portions,

() said central portions being secured together with their edges substantially in registration to provide a pair of bottom panels, one being an upper panel and the other being a lower panel,

(d) a pair of vertically disposed opposed end walls integral with one panel of said bottom panels;

(e) a pair of vertically disposed opposed side walls integral with the other panel of said bottom panels;

(f) said end walls being portions of one panel of said pair folded on themselves to provide an inner layer and an outer layer of fiberboard relative to the inside of said box with said inner layer and said outer layer at each end of the box integrally joined along a fold line defining the upper edge of each end wall;

(g) means integrally connecting said side walls with said other panel of said bottom panels comprising relatively narrow panels extending slantingly upwardly and outwardly relative to each other from said other panel of said bottom panels to said side walls,

(h) ventilating openings formed in said narrow panels,

(i) means integral with said side walls at their lower ends positioned at right angles to said side walls and disposed between the inner and outer layers of said end walls against which said narrow panels are held in their said slanted positions, and

(j) interlocking means at the upper edges of said end walls and integrally connected with said side walls for holding said side walls vertical and for holding said narrow panels in their said inclined positions,

(k) said inner layer of each end wall and the means integral with said side walls against which said narrow panels are held being disposed over and substantially in engagement with the uppermost of said bottom panels for supporting the box against collapse from superimposed loads.

(a) a pair of separate blanks of fiberboard, each having;

(b) a substantially corresponding, horizontally disposed, rectangular central portion;

(c) central portions being secured together with their edges substantially in registration to provide a pair of bottom panels, one being an upper panel and the other being a lower panel;

(:2) a pair of vertically disposed opposed side walls integral with the other panel of said bottom panels;

(g) extensions integral with said side walls at the corners of said box disposed between said inner and outer layers of said end walls;

(11) interlocking means respectively on said extensions and on said end walls at the junctures between said inner and outer layers in interlocking relation for holding said side Walls vertical and against movement from between said inner and outer layers;

(i) closure flaps integral with said side walls along their upper edges extending toward each other and over said bottom panels;

(j) said interlocking means being upward projections on said extensions substantially coplanar therewith, and openings formed in each of said end walls along said fold line through which said projections extend;

(k) tabs integral with said closure flaps extending at right angles thereto extending into said openings that are formed in each end wall along the upper edge of the latter for cooperating with said end walls to resist outward bowing of the latter under the force of contents of the box and to hold said extensions vertical;

(I) said interlocking means being spaced along the upper edge of each end wall from said side walls.

3. A lug box comprising:

(a) a pair of separate blanks of fiberboard, each having;

(c) said central portions being secured together with their edges substantially in registration to provide a pair of bottom panels, one being an upper panel and the other being a lower panel;

(g) extensions integral with said side walls at the corners of said box disposed between said inner and outer layers of said end walls; and

(h) interlocking means respectively on said extensions and on said end walls at the juncturcs between said inner and outer layers in interlocking relation for holding said side walls vertical and against movement from between said inner and outer layers;

(j) said interlocking means being upward projections on said extensions substantially coplanar therewith,

' 2. A lug box comprising:

and openings formed in each of said end walls along said fold line through which said projections extend; (k) tabs integral with said closure flaps extending at right angles thereto extending into said openings that are formed in each end wall along the upper edge of the latter for cooperating with said end walls to resist outward bowing of the latter under the force of the contents of the box and to hold said extensions vertical;

(1) said interlocking means being spaced along the up er edge of each end wall from said side walls;

(m) said projections extending upwardly above said closure flaps;

(n) openings formed in said bottom panels in vertical alignment below said projections adapted to receive the projections of the lower of a pair of vertically aligned superposed boxes of the same structure, in a stack thereof.

4. A lug box comprising:

(a) a pair of separate blanks of fiberboard, each having (b) a substantially corresponding, horizontally disposed rectangular central portion,

(c) said central portions being secured together with their edges substantially in registration to provide a pair of bottom panels, one being an upper panel and the other being a lower panel,

() a pair of vertically disposed opposed side walls integral with the other panel of said bottom panels;

(h) interlocking means respectively on said extensions and on said end walls at the junctures between said inner and outer layers in interlocking relation for holding said side walls vertical and against movement'frorn between said inner and outer layers;

(i) said extensions on said side walls extending substantially the full width of said end walls in a direction perpendicular to said bottom panels and comprising multiple layers of the fiberboard supported on said horizontally disposed panels atsaid end walls to thereby provide supports for said box at the corners thereof to resist collapse of said side and end walls under compression from the weight of a load on said side and end walls;

(j) said interlocking means comprising a pair of opposed upward projections respectively on the layers forming each of said extensions integrally united at their upper ends whereby each pair of opposed projections will be held together and whereby the projections of each pair thereof will reinforce each other against flexing and openings formed in said end walls along said lines of fold defining the upper edges of i said end walls through which said projections extend.

References Cited in the file of this patent UNITED STATES PATENTS 1,886,374 Breton Nov. 8, 1932 1,906,622 Kondolf May 2, 1933 2,246,097 lllges June 17, 1941 2,532,085 Carter Nov. 28, 1950 2,594,628 Evans Apr. 29, 1952 2,893,621 Harnish July 7, 1959 2,950,852 Hutchison Aug. 30, 1960 3,003,676 De Nola Oct. 10, 1961 3,015,431 Muicoy Jan. 2, 1962 FOREIGN PATENTS 862,060 Great Britain Mar. 1, 1961 GEORGE O. RALSTON, Primary Examiner.

Claims

1. A LUG BOX COMPRISING: (A) A PAIR OF SEPARATE BLANKS OF FIREBOARD, EACH HAVING (B) SUBSTANTIALLY CORRESPONDING, HORIZONTALLY DISPOSED, RECTANGULAR CENTRAL PORTIONS, (C) SAID CENTRAL PORTIONS BEING SECURED TOGETHER WITH THEIR EDGES SUBSTANTIALLY IN REGISTRATION TO PROVIDE A PAIR OF BOTTOM PANELS, ONE BEING AN UPPER PANEL AND THE OTHER BEING A LOWER PANEL, (D) A PAIR OF VERTICALLY DISPOSED OPPOSED END WALLS INTEGRAL WITH ONE PANEL OF SAID BOTTOM PANELS; (E) A PAIR OF VERTICALLY DISPOSED OPPOSED SIDE WALLS INTEGRAL WITH THE OTHER PANEL OF SAID BOTTOM PANELS; (F) SAID END WALLS BEING PORTIONS OF ONE PANEL OF SAID PAIR FOLDED ON THEMSELVES TO PROVIDE AN INNER LAYER AND AN OUTER LAYER OF FIBERBOARD RELATIVE TO THE INSIDE OF SAID BOX WITH SAID INNER LAYER AND SAID OUTER LAYER AT EACH END OF THE BOX INTEGRALLY JOINED ALONG A FOLD LINE DEFINING THE UPPER EDGE OF EACH END WALL; (G) MEANS INTEGRALLY CONNECTING SAID SIDE WALLS WITH SAID OTHER PANEL OF SAID BOTTOM PANELS COMPRISING