US2367410A - Carton corner construction - Google Patents

Description

5. LIGHTER CARTON CORNER CONSTRUCTION Filed Nov. 22, 1945 IN V EN TOR.

Patented Jan. 16, 1945 UNITED STATES PATENT OFFICE CARTON CORNER CONSTRUCTION Stephen Lighter, Milwaukee, Wis.

Application November 22, 1943, Serial No. 511,211

2 Claims.

The present invention relates generally to improvements in the art oi! manufacturing cartons, boxes or the like, and relates more particularly to improvements in the construction and operation of the corners for collapsible cartons formed of cardboard or similar material.

The primary object of this invention is to provide a new and useful carton corner construction which is simple and durable in construction, and which also facilitates assembly and collapse of the cartons to which it is applied.

Many different types of so-called collapsible or knock-down boxes or cartons have heretofore been proposed and used extensively for diverse purposes, and perhaps the majority of these prior cartons have been, formed of cardboard stock which is cut into unitary blanks properly scored for convenient assembly and collapse by folding along the score lines. During the formation of such boxes from cardboard stock, it is extremely desirable to utilize as little stock as possible for a carton of predetermined size, while maintaining maximum strength and rigidity of the assembled structures; and it is moreover exceedingly desirable to be able to assemble the receptacles quickly and conveniently in a manner whereby the assemblages will be automatically locked in assembled condition. While many prior attempts have been made to produce such self-locking carton assemblages, most of these prior devices are not commercially satisfactory either because they are too complicated and costly, or because they ton adapted to be formed of a single blank or sheet of material, and having in addition to the usual bottom and foldable side and endwalls, improved corner structures and locking devices which obviate the above mentioned objectionable features and difficulties.

Another specific object of the present invention is to provide animproved carton corner which may be formed of relatively thin cardboard stock or the like, to produce multiple reenforcement for the box to which the corner assemblages are applied.

A further specific object of my present invention is to provide an improved automatic lock and reenforcement for each corner of a box formed of a unitary blank of sheet material such as cardboard.

Still another specific object of this invention is to provide an improved carton comer construction which can be produced at moderate cost with minimum waste of stock, and which can be quickly and conveniently assembled to provide a strong and self-retaining box assemblage.

ihese and other specific objects and adyantages of the invention will be apparent from the following detailed description.

A clear conception of the several features constituting my present improvement, and of the mode of constructing and of assembling a carton corner involving the invention, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a plan view of a comer fragment of a blank for a collapsible carton, showing the same in collapsed or fiat condition, but cut and scored ready for folding;

Fig. 2 is a perspective view of the corner fragment of Fig. 1, with the side and end walls elevated approximately half-way;

Fig. 3 is another perspective view of the same co'rner fragment, showing the side and end walls almost, but not fully erected;

Fig. 4 is still another perspective view of the corner fragment, depicting the side and end walls fully elevated or erected, and also showing the corner construction almost assembled but not yet finally locked;

Fig. 5 is an additional perspective view of the corner fragment, illustrating the corner construction in finally assembled and locked condition; and v Fig. 6 is an enlarged transverse section through the assembled corner showing the locking tongue in action.

While the invention has been shown and de scribed herein as having been embodied in a single carton corner construction of specific dimensions and having vertical walls, it is not my desire or intent to thereby unnecessarily restrict the scope or utility vof the improvement, and it should be understood that more than one of the improved corners may be applied to the same carton or box.

Referring to the drawing, the improved carton shown therein may be formed of a single blank of cardboard and comprises in general, a flat rectangular bottom I having side walls 8 and end walls Sfoldably connected to its edges along score lines IO, II respectively; a triangular corner section I2 foldably connected to the end edge of the side wall 8 along a score line l3; a second triangular corner section It foldably connected to the end edge of the end wall 9 along a score line It, and also being foldably connected to the first mentioned corner section |2 along a diagonal score line IS; a third approximately triangular corner section i1 foldably connected to the free edge of the second corner section II along a score line l8 and having an integral locking tab or tongue l9 projecting outwardly from an edge thereof and cooperable with an opening 20 formed at the lower edge portion of the side wall 8; and a triangular panel 2| from which the tongue is has been cut, and which is foldably connected to the adjacent edge of the third corner section II along a score line 22.

All of the corner sections l2, I4, H, the bottom 1, the walls 8, 9, the panel 2|, and the tongue I9 are formed integral with each other and from a single blank, and in order to avoid waste of stock when producing these blanks, the corner sections l2, H, H and the panel 2| are all confined within the square bounded by the score lines l3, l5 and by the imaginary intersecting extensions of the outer upwardly swinging edges 23, 24 of the walls 8, 9 respectively. In order to insure proper folding of the corner sections l2, M when the side and end walls 8, 9 are swung into erect position, and in a structure wherein these walls are finally disposed perpendicular to the bottom I, the inclination of the score line l8 and f the corresponding free edge 25 of the triangular section |2 should each be disposed at an angle of 40 relative to the adjacent score lines I3, l5, and the fold line l6 should form an angle of 45 with each of the lines l3, IS. The locking tongue |9 should not be scored and should finally coact with the slot or opening 20 in the edge of the wall 8, as shown in Fig, 6, so as to provide a firm lock for the assembled corner; and while the panel 2| provides added strength and reeni'orcement for the assembled corner, this panel 2| may be omitted providing the fold line 22 properly coacts with the score line 3 in the finally erected assemblage as illustrated in Fig. 5. When the improved carton blanks have been properly cut and scored as shown in Fig. 1, they may be stacked in compact rectangular piles, and the self-locking corner assemblages may be applied to two or more corners of each blank. In order to erect or assemble a box from one of the blanks, it is only necessary to perform the several successive steps depicted in Figs. 2 to inclusive. During such assembly of a comer, the side and end walls 8, 9 should be swung upwardly away from the bottom 1 about their respective fold lines IO, N so as to cause the hingedly connected triangular corner sections l2, H to swing inwardly about their fold lines l3, l5 respectively, as illustrated in Fig. 2. Continued erection of the side and end walls 8, 9 will cause the corner sections i2, II to move toward overlapping position and these sections l2, H should be simultaneously pressed against the inner surface of the adjacent end-wall 9, see Fig. 3. As the overlapping or superimposed triangular sections l2, ll

approach their final position against the end wall s. the slot 20 will be opened; and the trian ular corner section II should be swung about the fold line l8, inwardly and downwardly over the free edge 25 of the comer section 2, as shown in Fig. 4. The panel 2| may be simultaneously folded in a reverse direction about its hinge line 22 so as to cause the locking tab or tongue l9 to project outwardly; and when the three corner sections I2, l4, H are finally pressed into snug superimposed position against the inner surface of the end wall 9 as in Figs. 5 and 6, the tongue I! will snap into the slot 20 to firmly lock the corner in assembled position. This final positioning of the corner sections I2, I4, I I will materially reenforce the wall 9 at the corner, and will also cause the panel 2| to hug the interior surface of the side wall 8 thereby likewise reenforcing this wall at the carton corner; and in order to dismantle or collapse the box, it is only necessary to withdraw the tongue I! from the slot 20 and to reverse the operations above described.

From the foregoing detailed description, it will be apparent that my present invention provides an improved carton corner construction which is simple, compact and sturdy in structure, and which is moreover adapted for rapid and convenient assembly and dismantling. The improved struc are is also self-locking and provides strong reenforcement for the corner of the carton to which it is applied, without undesirably obstructing the interior of the box. The new comer construction may be applied to any or all of the corners of a box, and besides eliminating waste of stock the corner structure utilizes the stock available within a rectangular blank to best advantage for reenforcing purposes. While the panel 2| may be omitted, it does serve to reenforce the. wall 8, and the corner section I! may also be widened at its outermost end in a direction toward the free edge 25 of the section I 2, if so desired. The blanks utilized in the formation of the improved cartons may also be produced of relatively thin cardboard stock and with the aid of simple equipment, and since these blanks lie flat when collapsed, they may be compactly stacked for storage and shipment. The automatically functioning locking tongues I9 serve to maintain the corners in assembled condition while also retaining the triangular sections |2, l4, l1 and the panels 2| snugly superimposed and against the adjacent walls, and the improved boxes can be manufactured at moderate cost and have proven highly satisfactory in actual use and are especially adapted for packaging laundry or the like.

It should be understood that it is not desired to limit this invention to the exact details of construction, or to the precise mode of assembly and dismantling, herein shown and described, for various modifications within the scope of the appeirzided claims may occur to persons skilled in the ar Iclaim:

1. A carton formed ofa single blank having a bottom provided with side and end walls foldably connected to the bottom and being disposable either perpendicular to or flatly collapsed into the plane of the bottom, the adjacent end edges of said side and end walls being foldably interconnected by a set of three approximately triangular corner sections one of which is foldably connected to one of said wall edges and another of which is likewise connected to the other or said wall edges and to said first mentioned section while the third section is foldably connected to said second mentioned section whereby said three sections are ioldable from flat position in the plane of said bottom into triple-ply substantially triangular formation lying flat against one of said walls, a tongue projecting from an edge of said third section and being insertible in a slot near the end edge of the wall which is not engaged by the folded corner sections so as to hold the three superimposed sections snugly against the other wall and to lock both walls inerected position, and a re-enforcing panel foldably connected to the edge of said third corner section from which the tongue projects and being adapted to lie fiat against the slotted wall when the tongue engages the slot, the direct connected edges of the first and second triangular corner sections being disposed at 45 angles with respect to the end edges of the walls when the blank is in flat condition and the other swinging edges of these two sections being disposed at 40 angles relative to the end edges of their supporting walls, and all three of the corner sections and the locking tongue and panel being formed from the blank stock originally disposed within the comer rectangle.

2. A carton formed of a single "blank having a bottom provided with side and end walls foldably connected to the bottom and being disposable either perpendicular to or flatly collapsed into the plane of the bottom, the adjacent end edges of saidvside and end walls being foldably interconnected by a set of three approximately triangular corner sections one of which is foldably connected to one of said wall edges and another of which is likewise connected to the other of said wall edges and to said first mentioned section while the third section is foldably connected to said second mentioned section whereby said three sections are foldable from flat position in the plane of said bottom into triple-ply substantially triangular formation lying flat against one of said walls, a tongue projecting from an edge of said third section and being insertible in a slot near the end edge of the wall which is not engaged by the folded comer sections so as to hold the three superimposed sections snugly against the other wall and to lock both walls in erected position, the direct connected edges of the first and second triangular corner sections being disposed at 45 angles with respect to the end edges of the walls when the blank is in flat condition and the other swinging edges of these tw sections being disposed at 40 angles relative to the end edges of their supporting walls, and all three of the corner sections and the locking tongue being formed from the blank stock originally disposed within the corner rectangle.

STEPHEN LIGHTER.

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