US2337198A - Carton - Google Patents

Description

Dec. 2l, 1943. M. E. HoLY 2,337,198,

CARTON Filed Sept. l5, 1941 2 Sheets-Sheet l f3 5f ff y 9 f:

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,Z3/; T" A .9 9 in f E? E 32 E 25 Dec. 21, 1943. M, How 2,337,198

CARTON Filed Sept. 15, 1941 2 Sheets-Sheet 2 Patented Dec. 21, 1943 CARTON Mitchel E. Holy, Philadelphia, Pa., assignor to Container Corporation of America, Chicago, Ill., a corporation of Delaware Application september 15.1941, serial No. 410,797

(ci. 22H9) 3Claims.

This invention pertains to cartons or contain; ers composed of paperboard, berboard and the like and, more particularly, -to so-called selflccking or snap-lock end closures for such articles wherein the closure ilaps are so constructed and arranged as to cause substantially automatic interengagement or interlocking of the end ilaps when they are infolded slightly beyond their intended nal relationship to one another;

One of the primary objects f the invention is to provide a self-locking or snap-lock end closure of such construction as to afford ease and speed of manipulation in eifecting closure of the carton end, the while providing a strong and relatively rigid carton end rmly resistant to forces tending to cause accidental opening.'

Another important object is to provide an inexpensive and simple snap-lock nap construction whereby all four of the naps at one end of a fourwalled carton may be interlocked with rapidity and sureness by easy manipulation. In this connection it should be stated that self-locking of four flaps of a carton end closure is not broadly new but prior structures of this sort are either complicated or expensive or inefficient or ineffective or otherwise unsatisfactory, the present invention avoiding all such defects of the prior art.

Still another important object is to provide a self-locking or snap-lock arrangement whereby all of the several locking iiaps may be interengaged simultaneously by a simple and practically single finger manipulation after the several interlocking flaps have been folded over the carton end in their proper order.

Many other objects and the advantages of the invention will be appreciated and understood, and numerous' uses will become apparent as the description and claims are read in conjunction with the drawings, in which:

Fig. 1 illustrates a certain blank, both ends of which embody the self-locking iiaps constituting a preferred form of the invention;

Fig. 2 is a perspective view of a carton formed from a blank such as that of Fig. 1 showing the rst closing operation with one pair of end closure ilaps folded inwardly over the carton end;

Fig. 3 is a View similar to that of Fig. 2 showing the second flap folding operation in process of being performed to effect the iirst lock;

Fig. 4 is a view similar to that of Fig. 2 showing the iinal flap folding operation to effect the iinal lock with the fourth flap; and

Fig. 5 is an end view of the carton with the though it is herein illustrated and described as applied to a. parallelepiped shape of iiberboard receptacle in which both ends embody the closure means of a preferred form of the invention. Obviously either end alone might be so equipped and the other end otherwise closed. A sheet of suitable material such as iiberboard is cut and scored in proper dimensions to provide the blank of Figure l including what willY be termed, for convenient reference, side panels 1 and 9, front and back panels 8 and I0, respectively, a securing strip II, and, at eachend, a series of interlocking closure naps designated I2, I3 and I4. Since the end closure flaps at one end are similar in shape, construction and function to those of the opposite end, a. description of one series should suiiice for both.

Score lines I5, I6, Il, I8, I9 and 2l segregate the several panels and closure aps from one another and permit, iirst, the panels to be folded into tubular body form with the adhesive carrying securing strip I I secured to the inner or outer face of side panel .l (depending on the direction of folding), and, second, the end closure naps to be folded at rightangles tothe side, back and front panels over the carton end and there interlocked with one another. Each of closure naps I2, at one end of the carton, has a kerf or slit, one part 22 of which intersects and extends from that free side edge of the iiap I2 which is adjacent to the front nap I3, to a, point, say onethird to two-fths of the width of the ap and there connects with a part 23 extending substantially at right angles to the first part and terminating a substantial distance short of the outer free edge of the nap. The two parts of each slit are joined, preferably by a fillet to avoid tearing of the liap and together provide a depressible tabblike part 24 normally occupying the plane of` the iiap but susceptible of being deected out of that plane momentarily during the locking operation to be described.

The inner portions 25 of the free side edges of rear closure ilap I4 converge outwardly and the outer portions are formed into what may be termed side or lateral locking tabs 26. The nap I4 is also provided with a U-shaped slit 21 disposed with the legs of the U directed toward the free outer edge 28 and the base of the U parallel or substantially parallel to the said free outer edge. The portion of flap I4 which is confined between the legs and base of the U-shaped slit, of course, normally occupies the plane oi the nap but, like the tab-like parts 24 defined by the slits 22-23, is susceptibleof being deflected out of such plane during certain locking operations hereinafter related. The flap I6 preferably is of a width, from score line 2| to its outer free edge 28, substantially equal to the width of the carton from front to rear'when set-up, i. e. equal to the width of the side wall panel 1 or 9, and the locking tabs 26 are so positioned withl respect to the slits 22-23`that the aps I2 and I4 may be interlocked with one another as will appear.

The front closure ap I3 preferably has arcuately converging free side edges 29 which terminate at a locking tab 3|v which, in turn, terminates the flap I3 and is designed to be passed through the slit 21 to effect interlocking of the ilaps I3 and |4. The width of flap I3, from the free terminal edge 32 of tab 3| to scoreline 2|, preferably is somewhat less than the perpendicular distance between the front and rear panels of the carton but in any event this flap I3 is proportioned suitably to t and interlock with the flap I4 as will be appreciated.

When the carton has been set-up into tubular form and its `end is to be closed the first operation is to fold the side ilaps I2 inwardly over the end of the package. Thereafter operations may progress in either of two ways, namely, the rear flap and front flap may be folded over the end and in the order mentioned, each being caused to lock with the underlying ilap or aps in succession or, the rear and then the front nap may be folded down over the end and the interlocking between the rear flap and the side aps and between the front ap and the rear flap effected simultaneously. In performing the locking operations by the successive method the rear ap I4 is folded down over and against the side flaps I2, whereupon pressure of the lingers of the operator applied along the center portion of the outer free edge 28 and in a direction tending to push `the aps into the tubular body of the carton, will cause the tabs 26 to depress these portions 24 which are bounded by the slits 22- 23 to positions out of the planes of the side aps and to positions where the outer ends of tabs 26 will pass through the slit parts 22. This operation is illustrated in Figure 3. Release of the finger pressure permits the natural resilience of the carton material to return the side and rear flaps to their normal flat positions across and square with the carton end, the three flaps being securely locked together.

A similar method of procedure serves to interlock the front and rear flaps. In this operation the front flap I3 is folded over and down against the outer surface of rear ap I4 and the operator presses against the outer surface of the front flap between the tab 3| and scoreline 2| (or I9 as the case may be) to bow the entire assembly of end aps inwardly of the carton body as is .illustrated in Figure 4. During this depressing or bowing of the aps the pressure of tab 3| against that portion of flap |4 -which is bounded by the base and legs of the U-shaped slit 21 will be depressed out of the plane of the flap to permit the tab 3| to pass through the slit 21. When the pressure is released after the outer edge or lip 32 of tab 3| has cleared the base of slit 21, the natural resilience of the material causes theilaps to return to their proper positions squarely across the carton end with all of the naps securely inter-locked in the manner intended.

Under some circumstances it may be desirable to effect the ap locking operations simultaneously as mentioned. ln such case the side llaps are first folded over and across the carton end and are followed in succession by the rear ap and then the front flap. After all of the ilapsvare in their end closing positions the operator presses against the front flap I3 in the same manner and to substantially the same extent (perhaps slightly more pressure is required) as that described above in connection with the interlocking of the front and rear flaps, whereupon all of the ilaps are bowed inwardly of the carton end and the tabs 26 caused to enter slit parts 22 and the tab 3| to enter slit 21. Release of nger pressure permits the aps to restore themselves to end closing positions at which time they will be securely fastened together as shown in Fig ure 5.

The double lock thus provided is particularly effective and gives a most secure and strong end closure of inexpensive and simple character. It is also of considerable significance that cartons so constructed may be set-up and closed with extreme rapidity by hand or by machine, it being a feature of the construction of the end closure that it lends itself to machine closing. Goods packaged in the carton, when forced against the end closure, do not cause the interlocked flaps to open but, on the contrary, tend to cause the interlock of the aps to become tighter and less susceptible of unlocking. Many other advantages might be mentioned.

Although the invention has been illustrated and described in a single preferred embodiment, it is capable of considerable modification and variation as well as of other adaptations. Consequently it is desired that the invention be limited only by its spirit and the scope of the appended claims.

I claim:

1. A self-locking end closure for cartons cornposed of foldable material and having two pairs of opposed side walls forming a tubular body comprising, an end closure flap attached to each of the side walls at one end of the body and adapted to fold inwardly over said carton and to close the same, each of one pair of oppositely disposed flaps having a slit including a part intersecting and extending from one of its free side edges intermediate of the ends of such edge toward the opposite free side edge of such nap and a part extending thence at an angle less than a straight angle toward but terminating short of the outer free edge of such flap, that one of the other pair of flaps which lies adjacent to those free side edges of the first said flaps opposite to the slit side edges of such flaps being provided with a laterally extending locking tab at the outer end portion of each free side edge thereof, said laterally extending tabs being adapted to be sprung through said slits, the last said flap being arranged to overlie the said slit flaps and having a slit therethrough wholly within its marginal bounds, the remaining closure ilap being adapted to overlie the third said flap and having a locking tab adapted to be sprung through the slit in the said third flap.

2. A self-locking end closure construction for cartons composed of foldable material and having two pairs of opposed side walls forming a tubular body comprising, an end closure nap attached to each of the side walls at one end of the body and adapted -to fold inwardly over said carton and to close the same, each of one pair oi oppositely disposed flaps having a slit including a part intersecting and extending from a free side edge intermediate o1' the ends of the edge toward the opposite free side edge of the iiap and a part extending thence at an angle less than a straight angle-to the first part toward but terminating short oi' the free outer edge of the nap, that one of the other pair of naps which lies adjacent to those free side edges of the rst side naps opposite to the slit side edges oi such flaps being provided with a laterally extending locking tab at the outer end portion of each tree side edge thereof, saidv laterally extending tabs being adapted to pass through the rst parts of said slits, the last said tlap being arranged to overlie the rst said pair of iiaps and having a U-shaped slit therethrough within its margins with the edges of the U directed toward the outer edge of the flap, the remaining closure iiap being adapted to overlie the third-mentioned flap and having a locking tab on its free outer edge adapted to be passed through said U-shaped slit in the third-mentioned ilap.

3. A self-locking end closure construction for cartons composed of foldable material and havF ing two pairs of' opposed side walls forming a tubular body comprising, an end closure iiap attached to each or the side walls at one end of the body and adapted to fold inwardly over said carton and to close the same, each of one pair of oppositely disposed naps having a slit including a part intersecting and extending from a free side edge intermediate of the ends of the edge toward the opposite free side edge of the iiap and a part extending thence substantially at a right angle to the first part toward but terminating short of the free outer edge of the nap, that one of the other pair of flaps which lies adjacent to said opposite free side edges of said pair of slit ilaps being provided with a laterally extending locking tab at the outer end portion of each free side edge thereof, said laterally extending tabs being adapted to pass through the first parts of said slits, the last said iiap being arranged to overlie the rst said pair oi' flaps and having a U-shaped slit therethrough within its margins with the edge of the U directed t0- ward the outer edge of the flap, the remaining closure flap being adapted to overlie the thirdmentioned ap and having a locking tab on its free outer edge adapted to be passed through said U-shaped slit in the third-mentioned nap. l MITCHEL E. HOLY.

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