US2595046A - Method of forming paper closure members for paper containers - Google Patents

Description

April 29, 1952 w. E. AMBERG 2,595,046

METHOD OF F ORMING PAPER CLOSURE MEMBERSk FOR PAPER CONTAINERS Original Filed Sept. 24, 1948 llliil N I////// //X/ l/ l/l I//m IN VEN TOR.'

Y ATTORNEYS.

Patented Apr. 29, 1952 METHOD F FORMING PAPER CLOSURE MEMBERS FOR PAPER CONTAINERS Walter E. Amberg, Beverly Shores, Ind., assgnor to Lily-Tulip Cup Corporation, Chicago, Ill., a corporation of Delaware Original application September 24, 1948, Serial PATENT CFF 2,595,046 I C E No. 51,043, now Patent No. 2,568,697, dated September 25, 1951. Divided and this application October 12, 1949, Serial No. 120,965

2 Claims. l

This invention is directed to the method of forming paper closure members for paper containers, and this application is a division of my co-pending application Serial Number 51,043 led September 24, 1948. The subject matter disclosed but not claimed herein is disclosed and claimed in my copending applications Serial No. 51,043, filed September 24, 1948, now U. S. Letters Patent No. 2,568,697, issued on September 25, 1951, and Serial No. 120,966, filed October l2, 1949, now U. S. Letters Patent No. 2,568,698, issued on September 25, 1951, the vsaid latter application also being a division of the former application.

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. Open-ended paper containers to be closed by pa-f per closure members are usually provided with an external rim at the open end thereof and an internal groove adjacent thereto. Paper closure 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 ange frictionally received in the open end of the paper container and overlying the rim thereof, or a paper cover having a dependingange adapted to snap over the external rim of the paper container.

In the first type of paper closure member, the stiff paper disc is diicult 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 flt 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 difficult and expensive to do with formed paper. After the paper discs are applied they are extremely difficult to remove and in this connection it is necessary to provide removing tabs or the like to the paper discs to assist in removing the same from the paper container. Quite often these removing devices tear o 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 difficulties encountered with the use of the stiff paper discs are overcome by the use of the second type of paper cloand, if too loose, leakage will occur.

sure member, but here other difficulties areencountered.- Since the paper cover having a flange received in the open end ofthe paper container and overlyingv the rim thereof is merely frictionally held in place on the container, it may be 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 alone for retaining the paper-cover in place on the paper container is Wholly inadequate. Here, also, tolerances Vare quite critical for if the fit is too loose leakage is bound to occur. v

As a result of the` foregoing diiiculties, great efforts have been made toward the third type of closure member, but here again iiherent difficulties 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 difficult Since the gripping action of thec'losure member takes place at the extremity thereof, it may be readily diminished by rough handling.

The principal object of this invention is t0 provide a suitable method for satisfactorily'producing an improved paper closure member free from the diiculties above referred to and providing the advantages of easy insertion into and removal from the container, secure engagement against dislodgement during handling and packing, not requiring critical t tolerances While at the same time providing a leak-proof seal with the container and serving to protect the rim or lip of the container from dirt and contaminaition.

thereof and an internal groove adjacent thereto,

the closure being made from a single sheet of paper board, and including a closureend 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 alignment with the end wall portion and extending beyond the 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 firmly 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 firmly held in place by the external compressed peripheral bead engaging in the internal groove. Because of the seal formed by the side flange portion and external bead of the paper closure member leakage of the contents of the paper container is effectively prevented and close-fit tolerances are not required.

Other objects and advantages will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawing, in which:

Figure 1 is a side elevational view of a paper container with the paper closure member made in accordance with this invention applied thereto;

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

Fig. 3 is a cross-sectional view of suitable apparatus for carrying out the method of this invention, with certain portions of the apparatus broken away and 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 I and includes a side wall I I which may be frusto-conical in contour for stacking purposes and provided at its bottom I2 with a bottom wall'. The upper open end of the paper container is provided with an external rim I3 and adjacent the upper open end of the paper container it is indented outwardly at I4 to form an internal groove I5.

The paper closure member adapted to be made by the method of this invention is generally designated at Il and it includes a closure end wall portion I8 and an upwardly extending side flange portion I9. The upper edge of the side flange portion I9 is provided with an external reentrant flange portion 20. The juncture of the closure end wall portion I8 and side flange portion I9 is deformed outwardly to form an external com-` pressed solid peripheral bead 2l at the juncture.

the bead being in substantial alignment with the end wall portion I8 and extending beyond the side flange portion I9.

The paper closure member Il is adapted to be received in the open end of the paper container In. The external bead 2l, forming a reinforced extension of the closure end Wall portion I8, is received in the annular groove I5 of the paper container and the side flange portion I9 may frictionally engage the side wall IIv of the paper container adjacent its open end. The external reentrant flange portion overlies the rim I3 to protect the same from dirt and contamination.

To apply the paper closure member to the paper container all that is necessary is to insertI it in the open end of the paper container, whereupon the external compressed peripheral bead 2I snaps into and engages in the internal groove I5 and the side flange portion may frictionally engage the side wall of the paper container. The side flange portion I9 and the external reentrant flange portion 20 operate during appligation of the closure member to prevent plunging of the same into the contents of the paper container. Because the external compressed peripheral bead 2l is a continuation of the closure end wall portion I8 it is rmly held in engagement with the internal groove I5. This firm engagement. especially when taken in conjunction with the frictional engagement of the side flange portion I9, prevents the paper closure member from being dislodged during handling or packing, also provides an effective 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 2H 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 out of the internal groove I5.

Referring more particularly to Figs. 3-5: suitable apparatus for carrying out the method includes a female die having a bottom Wall member 2'I which is movable between a retracted position illustrated in Figs. 3 and 4 and an advance position illustrated in Fig. 5; a male die 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 3 and movable with and relative thereto. The female die 25 is undercut or recessed at 26 to provide an opening into which the bottom member 2l is slidably disposed and to provide a lip 29 defining a smaller opening for receiving the male die 3i). The male die 3S and female die 25 being of cornplementary shape and of such relative dimensions as to provide, between the male die 36 and lip 29 on female die Z5, a peripheral space approximately equal in width to the thickness of the paper board to be operated upon (said thickness hereinafter being referred to as paper board thickness) and so as to provide between the plunger 30 and peripheral wall of recess 25 a peripheral space whose width is substantially greater than one paper board thickness and preferably less than two paper board thicknesses.

The female die 25 is preferably provided with an upwardly extending shoulder 28 constituting a male rim die cooperatively disposed with respect to a complementary groove, provided in the ring 3 I, 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 and together with the complementary portion 28 of die 25 provides die means for forming the closure rim and serves for confining or clamping the partially formed article during the latter part of the cycle of operations.

Fig. 3 illustrates the parts of the machine at g the start of the forming cycle. A paper board blank I'IA, circular in configuration for forming the paper closure member Il, is inserted on the top of the female die as illustrated in Fig. 3. The male die is then advanced to carry the paper board blank with it into engagement with the movable bottom wall 2l 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 i8 and a side ange portion I9. At this time the end wall portion lil is conned or clamped between the male die 30 and bottom wall member 2l and the upper margin of the flange i9 above the recess 25 is conned or clamped between the ring 3| and female die 25, with the intermediate zone of flange I9 relatively unconned because of the recess 26.

The ring 3| is then advanced and cooperates with the shoulder 28 on die 25 to form the external reentrant flange portion 29 on the upper edge of the side flange portion I9. At the end of these operations the machine parts take the positions illustrated in Fig. 4 wherein the paper board blank is formed into a closure end wall portion I8,

a side flange portion I9, and an external reentrant flange portion 20.

After the parts are in the position illustrated in Fig. 4 the end wall portion I8, the external reentranfi flange portion 20 and the side flange portion I9 remote from the juncture of the end wall and ilange portions are confined by the dies. Then 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 2l and the male die operates to deform and compress the side flange portion adjacent 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 solid compressed external peripheral bead 2|. The simultaneous movement of the bottom wall 27 of die 25 and the male die 39 is such as to compress the deformed external peripheral bead 2| in a vertical direction, between the shoulder 29 and bottom wall 21, while restraining it in a lateral direction, between the exteriorwall of male die 36 and the surrounding wall of recess 25, so that it becomes a solid compressed external peripheral bead which permanently holds its shape.

To remove the formed paper closure member from the machine the bottom wall 2l 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 IB 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 ember includes forming a paper board blank into a closure end Wall portion and a side 'flange portion, forming the edge of the side flange portion into an external reentrant ilange portion, and outwardly deforming the juncture of the closure end wall portion and side flange portion into a compressed solid peripheral external bead 2i in substantial alignment with the end wall portion Iii to produce a reinforced peripheral extension of the end wall portion.

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 is to be limited only by the scope of the appended claims.

I claim as my invention:

i. The method of making a paper closure member for a paper container comprising the'steps of forming a paper board blank into a closure end wall portion and an integral peripheral side flange portion, confining the end wall portion and a part of the flange portion remote from the juncture of the end wall and ange portions so as to leave an intermediate zone of said flange portion relatively unconllned, restraining said intermediate flange zone against inward radial movement while providing for limited restricted outward radial movement, and moving the confined end wall portion and the confined part of the flange portion toward each other to compress the material of the intermediate zone of said flange portion into a solid compressed external peripheral bead in substantial alignment with the end wall portion to produce a reinforced peripheral extension of the end wall portion.

2. The method of making a paper closure member for a paper container comprising the steps of forming a paper board blank into a closure end Wall portion and an integral peripheral side iiange portion, forming a part of the side flange portion remote from the juncture of the end Wall and flange portions into an external reentrant portion, confining the end wall portion and the remote part of the flange portion so as to leave an intermediate zone of said flange portion relatively unconilned, restraining said intermediate flange Zone against inward radial movement while providing for limited restricted outward radial movement, and moving the confined end wall portion and the confined part of the flange portion toward each other to compress the material of the intermediate zone of said ilange portion into a solid compressed external peripheral bead in substantial alignment with the end wall portion to produce a reinforced peripheral extension of the end w-all portion.

WALTER E. AMBERG.

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

UNITED STATES PATENTS Number Name Date 1,482,732 Calleson Feb. 5, 1924 1,575,300 Weeks Mar. 2, 1926 2,017,460 Hothershall Oct. 15, 1935 2,051,235 Willis Aug. 18, 1936 2,403,042 Bogoslowsky July 2, 1946 2,407,465 Zesbaugh Sept. 10, 1946

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