US2680558A - Opening device for cartons - Google Patents

Description

June 8, 1954 G. w. MAI 2,680,558 OPENING DEVICE FOR CARTONS Filed Jan. 10, 1951 2 Sheets-Sheet 1 INVENTORI GEORGE W MAI ATTORNEYS.

June 8, 1954 s. w. MAI 2,680,558 OPENING DEVICE FOR CARTONS Filed Jan. 10, 1951 2 Sheets-Sheet 2 INVENTOR: GEORGE w. MAI

wgwgw ATTORNEYS.

Patented June 8, 1954 UNITED STATE 2,680,558 OPENING DEVICE FOR CARTON S George W. Mai,

St. Loui lord Container Corpo corporation of Maryla s, Mo., assignor to Gayration, St. Louis, Mo., a nd Application January 10, 1951, Serial No. 205,332 1 Claim. (Cl. 229-5l) marginal portion of the sealing flap is free of glue so as to provide an unsecured grasping portion or tear tab which is torn therefrom thereby breaking the glue joint to open the carton. One of the principal objections to many of the conventional sealing flaps of ice cream and other food cartons arises from the frequent One of the principal objects of the present invention is to provide a device for cleanly detaching the glued sealing flap of folding cartons from the underlying wall to which it is attached without peeling portions of the surface of the paperboard in contact with the contents of the carton.

Another object of the invention is to provide a glued flap for closing a carton which will seecurely seal the package against any accidental or premature opening and which may be readily released from the glue bond without contaminating the contents or the package.

The invention provides means for readily and cleanly detaching a carton sealing flap connected to a free edge of one panel thereof, said sealing flap being attached to the margin of an adjacent wall panel by a longitudinal strip of glue of less Width than the sealing flap, said strip of glue being positioned slits therein, said means comprising a longitudipositioned between the glue strip and the inner longitudinal edge of the sealing flap, said slits being formed of perforations extending through the liner ply of the inner face of said sealing flap with the opposite ends of adjacent slits in substantially perpendicular alignment with said longitudinal series of slits.

In a preferred embodiment, the slits extend slit are in substantially substantially parallel to and are positioned between t breaking the glue joint to open the carton. The size of the perforations may be varied and still come within the scope of the invention.

comprise two adjacent rows of relatively short evenly spaced slits substantially parallel to the fold line of the sealing flap, the slits of the respective rows being in staggered overlapping relation. In other forms of the invention, the perforations may take the form of a row of Z-shaped slits, or a row of straight slits and a row of slits disposed at an angle to the straight slits adjacent to and parallel to the first mentioned row,

of diagonal slits. Regardless of the shape of the perforations the opposite ends of each staggered adjacent perpendicular alignment with the fold line of the sealing flap to provide the severed portions of adjacent staggered slit along a line perpendicw lar to the fold line of the sealing flap to insure an invariable clean tear of the liner along the end edge of the sealing severed by one of the bottom slits as illustrated in Figures 3 through 6.

The slits are preferably made from the outer or exposed face of the sealing flap, since the slits may be out simultaneously in one operation with the scoring and die cutting of the carton blank. Obviously, if desired they may be cut from the underiace of the blank, but this usually involves a separate operation.

The invention consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed. In the accompanying drawings which form part of this specification and wherein like numerals refer to like parts wherever they occur:

Fig. 1 is a plan view of a blank for a carton embodying this invention,

Fig. 2 is a perspective view of from the blank shown in Fig. 1 the tear tab severed,

the carton folded with a portion of Figs. 3, 4, and 6 are enlarged illustrations of several of the modified forms of the perforations of the invention.

Referring now to Figs. 1, 2 and 3 of the drawings in detail, it will be seen that the embodiment of the invention which is illustrated has been applied to a s andard one-piece ice cream carton. The blank is shown in Figure 1 wherein a cover panel l, a side or rear wall panel 2, a bottom panel 3, and a side or front wall panel l are defined by scores 5, t, 1, 8 and 9 and are provided with end flaps iii, H, i2 and [3 attached to the ends of wall panels I, 2, 3, and l, respectively. The cover panel l is provided with a sealing flap l4 defined by the score 6. A strip of glue I5 is applied to the undeiface of the sealing fiap M which in the erected position of the carton lies flatwise against front wall panel 4. The outer or free edge of the sealing flap it provides a sealing tear tab 16 which lies fiatwise against the front wall panel :2 in the assembled position of the carton. i'wo parallel lines of perforations or slits ii are substantially parallel to the free edge of the tear or peeling tab l5 and are near the score 8 along which the sealing flap Hi is folded to a position fiatwise against the front wall panel :3.

One way of assembling the carton comprises folding the bottom panel end flaps 12, the front panel A, and the rear panel 2 upwardly from the bottom panel 3, folding the front and rear wall end flaps i3 and i i inwardly and fastening them to each other, folding the cover panel end flaps ll! inwardly toward the box formed so that the lower edges of said end flaps it are positioned directly over the spaces between the upstanding bottom panel end flaps l2 and the joined front and rear wall end flaps is and ii, folding the cover panel l downwardly, applying an adhesive to form a glue strip l5, and folding the sealing flap l4 downwardly against the upper portion of the front wall panel 4. In a manufacturers variation of the assembly of the carton the tear tab it is secured first to the wall panel 6 whereupon the carton is shipped in llatwise condition. To open the carton the front and rear wall end flaps l3 and ii are disengaged and the tear tab it is grasped near one end thereof and pulled outwardly until the glue bond is broken, whereupon all portions of the carton may be readily opened and folded back into the plane of the bottom panel, thereby exposing the contents. The carton may also he opened by lifting upwardly at the center of the tear tab it. With this method of opening the tear tab it is not detached.

The parallel lines of perforations are spaced apart a sufficient distance to avoid the accidental breaking of the sealing flap i l by twisting but are sufiiciently close to insure an easy release of the sealing flap is. With this arrangement the liner on the underface oi the flap 34 does not tear at the extremities of the lower line of perforations and any tendency to tear is promptly arrested by the upper perforations, the ends of which slightly overlap the opposite ends of the lower perforations. Consequently, the liner on the inner face of the sealing flap M is completely severed by the staggered double row of perforations and any tendency to tear beyond the upper line of perforations is completely arrested.

Any tearing of the outer ply of the sealing flap [4 is arrested in a similar manner by each of the forms of perforations illustrated in Figures 4, 5 and 6.

In the embodiment described the distance between the two parallel lines of slits may be varied. Generally, the greater the thickness of the material the closer the rows of slits may be placed together. The space between the two rows is varied so as to allow for constant ease of opening for all grades of material.

It is to be understood that the embodiments herein described are illustrative and not restrictive, and it is also to be understood that the invention may be susceptible of embodiment in other modified forms, and that all such modifications which are similar or equivalent hereto come equally within the scope of the claim next appeering.

What I claim is:

A carton comprisng foldably, integrally connected bottom, side and top walls, the top and bottom walls having foldably connected, integral end flaps disposed right angularly inwardly in overlapping relation to form carton end walls, the side walls each having foldably, integrally connected end locking tabs disposed in releasably locked relationship and positioned against the outer face of the end flaps, the top wall having an integral sealing flap foldably connected to the front side margin thereof and disposed downwardly, flatwise against the upper portion of the outer f ce oi the adjacent side wall, the sealing flap secured to the adjacent side wall only by a longitudinal glue strip of substantially less width than the sealing and positioned parallel to spaced considerably inwardly from its free outer side edge thus leaving a free unsecured longitudinally extending marginal portion of the sealing nap, means for arresting tearing and peeling of the exposed liner ply on the underface of the sealin flap when the glue bond between sealing flap and the adjacent side wall is broken, said means comprising a row of closely spaced together, overlapping slits severing the exposed liner ply on the underface of the sealing flap, the row of slits being positioned closely adjacent and substantially parallel to the longitudinal glue strip, unsecured to the adjacent side wall, and spaced outwardly from the foldable connection between the glue strip and the top wall, whereby the said marginal portion of the sealing nap may be readily gripped with the fingers to enable the same to be pulled free from the adjacent side wall.

References sited in the file of this patent UNITED STATES PATENTS Number Name Date 1,961,375 McAleer June 5, 1934 2,181,837 Snyder et al Nov. 28, 1939 2,210,872 Ariail Aug. 13, 1940 2,218,599 Goodyear Oct. 22, 1940 2,285,542 Tasker June 9, 1942 2,535,531 Heywood Dec. 26, 1950 2,557,914 Miller June 19, 1951

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