US3037680A

US3037680A - Corner-lock carton

Info

Publication number: US3037680A
Application number: US46158A
Authority: US
Inventors: Robert J Hickin
Original assignee: Packaging Corp of America
Current assignee: Packaging Corp of America
Priority date: 1960-07-29
Filing date: 1960-07-29
Publication date: 1962-06-05
Anticipated expiration: 1979-06-05

Description

June 5, 1962 R. J. HICKIN CORNER-LOCK CARTON Filed July 29, 1960 IN VEN TOR United States Patent 3,037,680 CORNER-LOCK CARTON Robert J. Hickin, Seville, Ohio, assignor to Packaging Corporation of America, Rittman, Ohio, a corporation of Delaware Filed July 29, 1960, Ser. No. 46,158 Claims. (Cl. 229-435) This invention relates to cartons made from blanks of foldable sheet material such as paperboard, and it has reference particularly to cartons of the corner-lock type in which the mating edges of adjacent carton walls at the carton corners are joined in erected position by cooperating catches or hook members carried by one of such walls and slit means in the other wall, all as is well known in the carton art.

Ordinarily the catches or hook members are carried at the free edges of flaps hinged to one of the walls of the corner-forming pairs, and these flaps are disposed exteriorly of the other walls of the pairs with their catches inserted inwardly through the slit means of such other walls, but in some cases the flaps may be disposed interiorly with their catches passing outwardly through the slit means and hence disposed exteriorly of the other walls.

In paperboard cartons, to the production of which this invention is primarily directed, the characteristics of the material are such, due to lack of adequate rigidity, thickness or caliper, tear strength and the like, that the corner lock provided by the hook or catch and slit connection fails when the carton, particularly if loaded, is not carefully handled, by disengagement of the hook or catch from the slit means.

One object of the invention is to so improve the corner lock means that its failure will be guarded against.

Another object is to attain this desired improvement in a simple manner and without adding to the cost of the cartons.

A further object is to attain this desired object by means integral with the carton blank and produced in the blank during the blank-forming process.

Other objects and advantages of the invention will be apparent from the following description.

Broadly considered, the invention comprises the provision upon the hook or catch members of the corner locks of bosses which extend to their edges that engage the complemental edges of the slits, thus, in efleot, serving to increase the effective thickness of these edges in the zones of their cooperative engagement with the edges of the slits; and the said bosses may be, and preferably are, formed by a simple embossing operation such as may be performed with an ordinary creasing rule or score-forming tool, all as will be explained more in detail hereinafter and finally claimed.

In the accompanying drawing illustrating the invention, in the several figures of which like parts are similarly designated,

FIG. 1 is a plan view of the inner face of a carton blank embodying the invention,

FIG. 2 is an enlarged fragmentary section taken on the line 2--2 of FIG. 1, and

FIG. 3 is an enlarged fragmentary perspective view showing one end of the blank of FIG. 1 in erected condition.

'I he carton blank shown in FIG. 1 is more or less conventional, broadly considered, as related to cornerlock cartons or trays, and comprises a base, or bottom, panel member 1, side wall members 2 defined from the base panel member 1 by folding scores 3, and end wall members 4 defined from the base panel member by folding scores 5.

3,037,680 Patented June 5, 1962 'ice The opposite edges of the end wall members 4 are provided with flaps 6 foldable on hinge scores 7, and these flaps carry at their free edges the hooks or catch members 8 adapted, upon erection of the carton, to be engaged with the side wall members 2 by insertion through and engagement with the slit means 9--10 of these wall members.

In accordance with the invention the hooks or catch members 8 are provided with transverse bosses 11 which intersect their perimeters at two spaced locations and extend substantially vertically of them when in erected condition and serve, due to the fact that they offstand from the plane of the blank, to provide offsets which increase the eifective thickness of the flaps particularly in the zones of their edges 8 which engage the portions :10 of the slits 910. These bosses may be produced simply and cheaply during the blank-forming process by the operation of a conventional creasing rule or scoring tool as hereinbefore stated.

The carton or tray of the invention may be erected in the manner and with mechanisms conventionally used in the setting-up of corner-lock cartons, whereby, when the side walls 2 have been erected, the end walls are erected with their flaps 6 embracing the side walls and the hook or catch means 8 inserted through the slit means 9-10 to effect locking engagement of the parts.

Although, as shown particularly in FIGS. 1 and 3, the bosses 11 offstand inwardly from the inner faces of the hook or catch means 8, they may, particularly if the flaps 6 are disposed inwardly of the side wall members 2 as hereinbefore suggested, oifstand outwardly from the outer faces of the hook or catch means 8, if desired.

In addition to their function in enhancing the locking engagement of the hook or catch and slit means of the corner lock, the bosses 11 extending inwardly of the side walls will so space moist or greasy products packed in the carton from the edges of the books or catches and the edges of the slit means in the side walls as to prevent unsightly wicking of moisture or grease into these parts.

Various changes and modifications are considered to be within the principle of the invention and the scope of the following claims.

What I claim is:

l. A corner-lock carton, having a base panel member and a pair of wall members at a corner of said base panel member and olfstanding angularly from said base panel member, a flap hinged to the corner-forming edge of one of said wall members and cooperating with the other wall member to form said corner, said other wall member being provided with slit means spaced from the corner-forming edge thereof, said flap being provided with a catch member insertable through said slit means when said wall members are erected to corner-forming relation, said catch member having a perimetral portion thereof abuttingly engaging an edge of said slit means to effect interlocking of said wall members at said corner, said catch member being provided with a transverse boss offstanding from the plane of the catch member and intersecting the perimeter thereof at two spaced locations to provide an offset in the zone of its abutting engagement with said edge of the slit means,

2. A carton as defined in claim 1, in which said boss extends across said catch member in a direction substantially normal to said base panel member.

3. A carton as defined in claim 1, in which said flap is disposed against the outer surface of said other wall member with said catch member disposed against the inner surface thereof, the boss of said catch member offstanding therefrom inwardly of the carton wall.

4. In a corner-lock carton, having a base panel member, pairs of wall members otfstanding substantially normal to said panel member and having their meeting end edges forming corners for the carton with the said end edges of the walls of said pairs joined by corner locking means comprising catch means carried by flaps hinged to the corner-forming edges of one wall of a pair and complemental slit means in the other wall of the pair and spaced from the corner-forming edge thereof with an edge of the catch means abuttingly engaging a complemental edge of the slit means, the improvement which comprises boss means on said catch means extending transversely thereof and offstanding from the plane of the catch means and intersecting its perimeter at two spaced locations to provide an offset in the Zone of its abutting engagement with said edge of the slit means.

5. A blank for a corner-lock carton, comprising a sheet of foldable material provided with cuts and folding scores defining a base panel member, side and end wall members foldably attached to said base panel member at its borders and erectable substantially normal thereto with their end edges in juxtaposition at the corners of the base panel member, and corner-lock means for said members including slit means in one of said wall members spaced from a corner-forming edge thereof and catch means carried by a flap hinged to the corner-forming edge of the other wall member, said catch means having a perimetral edge and serving for insertion through said slit means and for abutting locking engagement with an edge thereof when said wall members are erected in corner-forming relation, said catch means being provided with a transverse boss otfstanding from the plane of the catch means and intersecting its perimetral edge at two spaced locations, said boss thus serving to provide an offset in the zone of abutting engagement of said catch means with the said edge of the slit means.

References Cited in the file of this patent UNITED STATES PATENTS 1,652,251 Oliver Dec. 13, 1927 1,796,035 Maier Mar. 10, 1931 2,677,493 Wanda May 4, 1954 2,901,158 Carpino Aug. 25, 1959