US2568697A - Paper closure member for paper containers - Google Patents

Description

:azzlazzaz w. E. AMBERG PAPER CLOSURE man FOR PAPER couumnns Filed Sept. 24, 1948 Sept. 25, 1951 Z; M 5. W49 fly/flm pm;

Patented Sept. 25, 1951 PAPER CLOSURE MEMBER FOR- PAPER CONTAINERS Walter E. Amber'g, Beverly Shores, Ind., assignor to Lily-Tulip Cup Corporation, Chicago, 111., a corporation of Delaware Application September 24, 1948, Serial No. 51,043

2 Claims. (01. 229-43) This invention is directed to paper closure members for paper containers. The subject matter disclosed but not claimed herein is disclosed and claimed in my co-pending divisional applications Serial No. 120,965 and Serial No. 120,966, filed October 12, 1949.

Heretofore, various types of paper closure members for paper containers have been proposed and utilized but they have all, for various reasons, failed to produce satisfactory results. Openended paper containers to be closed by paper closure members are usually provided with an external rim at the open end thereof and an internal groove adjacent thereto. members for such paper containers have been generally of three types, a. stiff paper disc adapted to fit in the internal groove of the paper container, or a paper cover having a flange frictionally received in the open end of the paper container and overlying the rim thereof, or a paper cover having a depending flange adapted to snap over the external rim of the paper container.

In the first type of paper closure member, the stiff paper disc is diflicult to insert into'the annular groove of the paper container. Extreme care in application is required for any tilting of the paper disc or any application of uneven pressure usually results in plunging the paper disc into the contents of the paper container with consequent spilling and contamination of the contents. The fit of the paper disc in the annular groove is also critical for, if the fit is too tight. the paper disc is too difficult to apply, and if the fit is too loose leakage will occur. Extremely close tolerances must be maintained and this is diflicult and expensive to do with formed paper. After the paper discs are applied they are extremely difiicult to remove and in this connection it is necessary to provide removing tabs of the like to the paper discs to assist in removing the same from the paper container. Quite often these removing devices tear off from the paper discs during the removing operation. Further, the rims of the paper containers are not protected by the paper discs and they become dirty and contaminated and result in contamination of the contents when poured from the paper container. Some of the foregoing difliculties encountered with the use of the stiff paper discs are overcome by the use of the second type of paper closure member, but here other difficulties are encountered. Since the paper cover having a flange received in the open end of the paper container and overlying the rim thereof is merely frictionally held in place on the container, it may be Paper closure readily dislodged causing spilling of the contents of the container. Substantially any upward force applied to the flange, as during handling or packing the containers, will operate to dislodge the cover. It has been-found that the use of friction v alone for retaining the paper cover in place on the paper container is wholly inadequate. Here, also, tolerances are quite critical for if the fit is too loose leakage is bound to occur.

As a result of the foregoing difficulties, great efforts have been made toward the third type of closure member, but here again inherent di'fliculties have been encountered. The paper cover having a depending flange adapted to snap over the external rim of the paper container must, of necessity, project beyond and below the rim of the paper container. This requires extra space for the packing of the closed containers and also requires extreme care in handling and packing. If the projecting edge of the depending flange of the paper closure member is severely bumped or is hung up on the top of an adjacent container during packing, the closure member is almost invariably dislodged resulting in spilling and contamination of the contents of the container. Here, also, the tolerances are quite critical for, if the fit between the closure member and the container is too tight, the application and removal of the closure member becomes diflicult and, if too loose, leakage will occur. Since thegripping action of the closure member takes place at the extremity thereof, it may be readily diminished by rough handling.

The principal object of this invention is to provide an improvedpaper closure member for a paper container wherein the difficulties encountered by the foregoing paper closure members are eliminated, wherein the paper closure member may be easily applied to and removed from the paper container, wherein the paper closure member is securely held in place on the paper container, wherein the paper closure member cannot be dislodged during handling or packing, wherein critical fit tolerances are not required, wherein leakage between the paper closure member and the paper container is eliminated, and wherein the rim of the paper container is protected from dirt and contamination.

The paper closure of this invention is adapted for use with a paper container having an external rim at the open end thereof and an internal groove adjacent thereto, the closure being made from a single sheet of paperboard, and includin a closure end wall portion and an integral side flange portion extending upwardly therefrom throughout the periphery thereof. The juncture of the end wall portion and the side flange portion consists of a compressed solid peripheral bead in substantial planar alignment with the periphery of the end wall portion and extending beyondthe upwardly extending flange portion to form a reinforced peripheral extension of the end wall portion. The side flange portion lies adjacent the open end of the paper container and the compressed solid peripheral bead, forming an extension of the end wall portion, snaps into the internal groove of the paper container and is held flrmly therein. Thus, the paper closure member is positively retained in the paper container by the compressed solid peripheral bead.

Preferably, the upper edge of the side flange portion is formed outwardly into an external reentrant flange portion to overlie the rim of the paper container to protect the same from dirt and contamination. The side flange portion also operates to prevent plunging of the paper closure member into the contents of the paper container during application of the closure member and provides a strong and readily accessible means for removing the closure member from the paper container. Any application of force to the external reentrant flange portion of the paper closure member during handling or packing will not. dislodge the closure member for it is flrmly held in place by the external compressed peripheral bead engaging in the internal groove. Because of the seal formed by the side flange and external head of the paper closure member leakage of the contents of the paper container is eflectively prevented and close-fit tolerances are not required.

A further object of this invention resides in the cooperative relationship between the paper container and the paper closure member of this invention.

Other objects and advantages will become apparent to those skilled in the art upon reference to the accompanyin specification, claims, and drawing, in which Figure l is a side elevational view of a paper container with the paper closure member of this invention applied thereto.

Fig. 2 is an enlarged partial sectional view taken substantially along the line 2-2 of Fig. 1 illustrating the cooperative relationship between the paper container and the paper closure member.

Fig. 3 is a cross-sectional view showing suitable apparatus, with certain portions broken away, for forming the paper closure member with the parts in a position at the start of the forming cycle.

Fig. 4 is a view similar to Fig. 3 but showing the parts midway in the cycle of operation.

Fig. 5 is a view similar to Figs. 3 and 4 but showing the parts at the completion of the cycle of operation.

Referring first to Figs. 1 and 2 the paper container is generally designated at It and includes a side wall H which may be frustro-conical in contour for stacking purposes and provided at its bottom l2 with a bottom wall. The upper open end of the paper container is provided with an external rim l3 and adjacent the upper open end of the paper container it is indented outwardly at H to form an internal groove IS.

The paper closure member of this invention is generally designated at H and it includes a closure end wall portion I8 and an upwardly extending side flange portion [9. The upper edge of the side flange portion I 9 is provided with an external reentrant flange portion 20. The ,Iuncture of the closure end wall portion i8 and side flange portion I9 is deformed outwardly to form an external compressed solid peripheral bead 2! at the juncture. the bead being in substantial planar alignment with the periphery of the end wall portion l8 and extending beyond the side flange portion IS.

The paper closure member I! is adapted to be received in the open end of the paper container III. The external bead 2|, forming a reinforced extension of the closure end wall portion I8, is received in the annular groove l5 oi the paper container and the side flange portion ll may frictionally engage the side wall ll of the paper container adjacent its open end. The external reentrant flange portion 20 overlies the rim II to protect the same from dirt and contamination.

To apply the paper closure member to the paper container all that is necessary is to insert it in the open end of the paper container, whereupon the external compressed peripheral bead 2l snaps into and engages in the internalgroove l5 and the side flange portion may frictionally engage the side wall of the paper container. The side flange portion l9 and the external reentrant flange portion 20 operate during application of the closure member to prevent plunging of the same into the contents of the paper container. Because the external compressed peripheral bead 2| is a continuation. of the closure end wall portion It it is firmly held in engagement with the internal groove l5. This firm engagement, especially whentaken in conjunction with the triotional engagement of the side flange portion It, prevents the paper closure member from being dislodged during handling or packing, also provides an eifective seal between the paper closure member and the paper container and eliminates the necessity for extremely close-fit tolerances as heretofore required.

In order to remove the paper closure member from the paper container, all that is necessary is to uncurl a portion of, the external reentrant flange portion 20 so that it may be firmly grasped to pull the closure member from the container. Upon such pulling the external compressed peripheral bead 2| of the paper closure member is snapped vout of the internal groove I 5.

Referring more particularly to Figs. 3-5: apparatus suitable for making the paper closure of this invention includes a female die 25 having a bottom wall member 2! which is movable between a. retracted position illustrated in Figs. 3 and 4 and an advance position illustrated in Fig. 5; a male die 30 movable relative to said female die from a retracted position illustrated in Fig. 3 to an advance position illustrated in Fig. 4; and a die ring 3| surrounding said male die 30 and movable with the relative thereto. The female die 25 is undercut or recessed at 26 to provide an opening into which the bottom member 21 is slidably disposed and to provide a lip 29 defining a smaller opening for receiving the male die 30. The male die 30 and female die 25 being of complementary shape and of such relative dimensions as to provide, between the male die 30 and lip 29 on female die 25, a peripheral space approximately equal in width to the thickness of the paperboard 'to be operated upon (said thickness hereinafter being referred to as paperboard thickness) and so as to provide between the plunger 30 and peripheral wall of recess 20 a peripheral space whose width is substantially greater than one paperboard thickness and preferably less than two paperboard thicknesses.

The female die 25 is preferably provided with an upwardly extending shoulder 28 constitutin a male rim die cooperatively disposed with respect to a complementary groove, provided in the rin 3|, constituting a female rim die which surrounds the male die 30. The ring 3| is movable from a retracted position as illustrated in Fig. 3 to an advance position as illustrated in Figs. 4 and 5 an together with the complementary portion 28 of die 25 provides die means for forming the closure rim and serves for clamping the partially formed article during the latter part of the cycle of operations.

Fig. 3 illustrates the parts of the machine at the start of the forming cycle. A paper board blank IIA, circular in configuration for forming the paper closure member I1, is inserted on the top of the female die as illustrated in Fig. 3. The male die is then advanced to carry the paper blank with it into engagement with the movable bottom wall 21 of the female die when the bottom wall is in its retracted position- This operation forms the paper board blank into a closure end wall portion l8 and a side flange portion IS.

The die ring 3| is then advanced and cooperates with the male rim die 28 to form the external reentrant flange portion 20 on the upper edge of the side flange portion l9. At the end of these operations the machine parts take positions illustrated in Fig. 4 wherein the paper blank is formed into a closure end wall portion ill, a. side flange portion l9, and an external reentrant flange portion 29.

After the parts are in the position illustrated in Fig. 4 the movable bottom wall 21 is advanced simultaneously with retraction of the male die 30 to the positions illustrated in Fig. 5. This simultaneous movement of the movable wall 21 and the male die 30 operates to deform the juncture of the closure end wall portion and side flange portion of the paper closure member outwardly into the annular recess 26 to form the relatively rigid external peripheral bead 2 I. The simultaneous movement of the bottom wall I! and the male die 30 is such as to compress the deformed external peripheral bead 2| so that it becomes a relatively rigid external bead which permanently holds its shape.

To remove the formed paper closure member from the machine the bottom wall 21 of the female die, the male die 30, and the female rim die 3| are retracted and a plunger 32 is moved upwardly against the center of the closure wall [8 to snap the paper closure member from the annular recess 26. The parts are then in the position to repeat the cycle of operation. If desired, the female die 25 may be radially severed into a plurality of segments and they may be moved outwardly for the purpose of clearing the external peripheral bead 2! of the paper closure member to provide for ready removal of the paper closure member from the machine in the event that snap removal is not desired.

Thus, the method of forming the paper closure member includes forming a paperboard blank into a closure end wall portion and side flange portion, forming the edge of the side flange portion into an external reentrant flange portion, and outwardly deforming the juncture of the closure wall and side flange into a compressed solid peripheral external bead.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and therefore this invention isto be limited only by the scope of the appended claims.

I claim as my invention:

1. A paper closure member, adapted for use with a paper container having an internal groove adjacent the open end thereof, comprising a single sheet of paper board formed into a closure end wall portion and an integral side flange portion extending upwardly therefrom throughout the periphery thereof, the juncture of said portions consistin of a compressed solid peripheral bead in substantial planar alignment with the periphery of the end wall portion and extending beyond the upwardly extending flange portion to form a reinforced peripheral extension of the end wall portion for engagement in the internal groove of the paper container.

2. A paper closure member adapted for use with a paper container having an external rim at the open end therof and an internal groove adjacent thereto, comprising a single sheet of paper board formed into an end wall portion and an integral side flange portion extending upwardly therefrom throughout the periphery thereof, the juncture of said portions consisting of a compressed solid peripheral bead in substantial planar alignment with the periphery of the end wall portion and extending beyond the upwardly extending flange portion to form a reinforced peripheral extension of the end wall portion for engagement in the internal groove of the paper container, and said upwardly extending side flange portion having an external reentrant portion for receiving the external rim of the paper container.

WALTER E. AMBERG.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS France Feb. 4, 1935

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