US3464575A - Container closure - Google Patents

Description

p 2, 1969 v. ARSLANIAN ET AL 3,464,575

CONTAINER CLOSURE Filed Jan. 26, 1967 INVENTOR5 VINCENT ARSLANIAN W. J WEBER nited States Patent 3,464,575 CONTAINER CLOSURE Vincent Arslanian and William J. Weber, Fulton, N.Y., assignors to Phillips Petroleum Company, a corporation of Delaware Filed Jan. 26, 1967, Ser. No. 612,000 Int. Cl. B6511 39/00 U.S. Cl. 215-41 12 Claims ABSTRACT OF THE DISCLOSURE A resilient container closure having a thickened discoidal stopper portion, serving to reinforce sealing of the cap inside the container opening, and an enclosing cap portion which seals against the outer diameter of the container opening.

This invention relates to a formed closure for a container. In one aspect, it relates to a closure formed of a thin sheet of resilient material having a reinforced internal stopper-type disk for effecting a tight seal to the opening of the container. In another aspect, it relates to a closure for a container which maintains a seal of the container internally by means of a reinforced sealing disk, and externally by means of resilent contact with the outside of the container. In another aspect, it relates to a reusable container closure which can be removed from a container without destruction because its reinforcing sealing member is integral with the closure. In another aspect, it relates to a closure of resilient sheet material having thickened portions for reinforcing the seal between the closure and the container, and for providing for easy removal of the closure from the container. In another aspect, it relates to a closure for a container having both reinforced integral stopper means to fit inside container opening, and a dependent skirt to fit outside the container opening. In a more specific aspect, it relates to a cap for a milk bottle formed of a single piece of material, and having a reinforced stopper portion made integral with the cap. In yet another aspect, it relates to closures made of resilient thermoplastic material. In another aspect, it relates to a closure having an integral reinforced sealing disk provided with venting means to prevent excessive pressure buildup within a container.

A great number of container closures have been formed of resilient sheet material, such as synthetic thermoplastics. Many of these closures have been of the covering type, which merely fits over the outside of a container opening and seals around a bead or other seating device provided on the exterior of the container opening. It has also been proposed to make such closures of a stopper type, fitting inside the bore of a container opening, as well is a combination type which comprises both a stopper portion and a dependent skirt which fits around the outside of the container opening. This invention is concerned with this latter type of closure.

Previous workers in the field have found that container closures made of a thin sheet of resilient material, such as thermoplastic, are not very effective for sealing the inside of the bore of a container opening. The resiliency of the material, which is the very factor that makes it possible to use in such an application, also makes it quite li able to he accidentally dislodged if the container is dropped or bumped. In order to maintain an effective seal in the stopper portion of such a closure, therefore, other workers have resorted to a reinforcing disk, as is shown in Wilcox, US. Patent 3,059,799, or a reinforcing ring, as is shown in Aldington, US. Patent 3,109,575. Such reinforcing disks or rings must be removed before the resilient cap is taken from the container, which represents an extra operation 3,464,575 Patented Sept. 2, 1969 in opening the container. Furthermore, in some cases, the reinforcing disk or ring is inherently destroyed in the process of removing it from the container, and thus the container cannot be rescaled as tightly as the original seal. Container closures of this type, therefore, do not represent either the maximum economy of manufacture or efliciency and convenience in use and reuse of the closures.

It is therefore an object of this invention to provide a new container closure having both stopper and covering portions. It is a further object of this invention to provide a container closure having an integral reinforced stopper portion. It is a further object of this invention to provide a reusable closure of resilient sheet material. It is a further object of this invention to provide an economical, tight-sealing, one-piece milk bottle cap. It is a further object of our invention to provide container closures of resilient sheet material which can be stacked for use in automatic capping machinery. It is a further object of this invention to provide a closure capable of venting excessive pressures which build up within a container. It is yet a further object to provide a closure for a plastic, metal or glass container.

These and other objects are achieved by the container closure of our invention as described in this specification, the drawings and appended claims.

According to the invention, a container closure is made of resilient sheet material having a thickened stopper portion which serves to reinforce the sealing of the stopper portion against the internal bore of the container opening, or to seal to the underside of an inwardly disposed lip in the internal bore of a container opening.

The closure of our invention can readily be seen by reference to the drawings. FIGURE 1 shows two closures of our invention in stacked relationship. FIGURE 2 shows a closure of our invention applied to a bottle. FIGURE 3 show the closure applied to a container opening having an inwardly disposed lip. FIGURE 4 shows an embodiment wherein the reinforced stopper portion is provided with venting means to vent excessive pressure from the container. FIGURE 5 is a different vieW of the embodiment shown in FIGURE 4.

Referring now to FIGURE 1, it will be seen that the closure of our invention is a one-piece closure, preferably made by thermoforming. The distinctive feature of the closures of our invention is the variation in the thickness in the different portions of the closure. The closure is formed having a central discoidal portion 11 of relatively thick material. At its perimeter, this discoidal portion is provided with a generally cylindrical, upstanding wall structure 12 which terminates at its top in an outwardly extending annular ring portion 13. At the outer extremity of ring 13 is a downwardly depending, skirt 14. In general, the skirt flares outwardly. FIGURE 1 shows such an outwardly flaring skirt 14. In a currently preferred embodiment, depending skirt 14 is formed of progressively thicker material in a downward direction, having maximum thickness at its lower extremity to provide reinforcement for grasping and removing the cap from a container.

In the embodiment shown in FIGURE 1, the outwardly flaring skirt portion terminates at the bottom with a cylindrical, upstanding portion 15 which is itself terminated at its lower extremity with outwardly extending annular bead 16. When a plurality of closures are in a stacked position, the interior lower face of bead 16 of an upper closure will contact shoulder 17 of a lower closure. It will thus be seen that a stack of closures which is accidentally compressed will not become stuck together because shoulder 17 prevents skirt 14 of the upper closure from contacting skirt 14 of the lower closure and becoming locked together because of the frictional forces.

In the currently preferred embodiment, an inwardly extending portion 19 is provided on cylindrical wall 12 to allow some axial and radial flexing of wall 12 to allow for the proper seating of disk 11 in a bottle. As is shown, cylindrical wall 12 is composed of lower cylindrical portion 18, which has an outer diameter equal to that of discoidal portion 11. Surmounting cylindrical portion 18 is inwardly extending ring portion 19. Above ring portion 19 is an upper cylindrical portion 21 which has an internal diameter greater than the external diameter of lower cylindrical portion 18. Thus, when the closures are stacked, discoidal portion 11 will fit inside of upper cylindrical portion 21. Because the external diameter of discoidal portion 11 and of lower cylindrical portion 18 are less than the inner diameter of upper cylindrical portion 21, the caps will not stick together, and a cap can readily be removed from either the top or the bottom of the stack.

FIGURE 2 shows the closure of our invention applied to a container opening. As is shown, stopper portion 11 has suiiicient strength and rigidity to form a. tight seal with the inside of bore 22 of the container opening. A second seal is provided outside the container opening where the thinner resilient material conforms itself to bead 23 to form a seal along 24. Thus, the closure of our invention provides a double seal to prevent leakage of the contents of the container. As is also shown in this figure, the outwardly flaring skirt portion of the closure terminates in head 16 which stands out considerably from the container. This bead is therefore easy to grasp for removal of the closure from the container and, furthermore, due to its thickened nature, is resistant to tearing during the removal operation. The closure of our invention may, therefore, be reused after removal from the container, and it will be seen that this closure provides as good a seal upon reuse as it did originally.

The closure of our invention can also be used with containers on which the opening is provided with an inwardly disposed lip on the internal bore. Such a con tainer is shown, for example, in FIGURE 3. The wall of container opening 26 is bent outwardly to form an out wardly disposed bead 27, and then inwardly to form lip 28. As is shown in FIGURE 3, the closure of our invention will form a double seal with this type of container opening also, having an external seal at 29, and forming an internal seal underneath lip 28. It should be noted that internal pressure in the container will cause the seal between the closure and the lower edge of lip 28 to become even tighter due to an accordion effect on the resilient closure material. Although a container having the opening such as that demonstrated in FIGURE 3 could be made of glass, it would far more likely be made of plastic or metal.

An embodiment of the closure of our invention which has provision for venting of internal pressures from the container is shown in FIGURE 4. In this embodiment, the thickened reinforcing disk portion of the closure is provided with a number of grooves 30 around its periphery. As pressure increases inside the container due to generation of gas or thermal expansion of the contents, gas and/or liquid from the top of the container will flow readily through grooves 30. The pressure of this fluid is sufficient to escape between the depending outer skirt 14 and the bottle wall because of the relative thinness and flexibility of the depending skirt wall at that point. The strength of the material in the depending skirt is such that it will maintain a tight seal under the pressure of liquid in the container if the container is merely inverted, but the material is sufficiently thin that fluid pressure within the bottle can escape before damage is done to the bottle itself. When the embodiment of the closure of our invention without venting grooves is placed on a standard glass milk bottle, reinforced disk 11 forms such a tight fit in the neck of the bottle that the bottle itself can be broken due to the thermal expansion of milk inside the bottle. It is, therefore, necessary to use the vented embodiment of the closure wherever it is expected that there 4 will be sufliciently large thermal change to cause damage to the container.

A cutaway view of the vented embodiment of our invention is shown in FIGURE 5, showing the position of the venting grooves around the periphery of the reinforcing disk.

As stated above, the resilient material used for forming the closure of our invention is generally a synthetic thermoplastic material. Materials which are particularly preferred for such an application are polystyrene, polyvinyl chloride and polyolefins, although the invention is not limited to these specific materials, but may include other thermoplastic materials alone or in laminated form, as for example a thermoplastic coated paper.

The closures of our invention can be used with containers of various types. As has been mentioned above, the invention is particularly applicable to closures for milk bottles. The closure can also be used, however, for cottage cheese-type containers, which generally are made of formed thermoplastic material, or of helically wound paper. The closure could also be applied to metal containers, such as metal cans for coffee or peanuts. The type and material of the container is therefore not limited, but may be any container which has an opening adapted to be closed by one of the closures of our invention.

The thickness of the discoidal portion of the closure can be varied depending upon the size of the container opening and the amount of reinforcement necessary to prevent accidental opening under the conditions of use of the particular container. In general, the discoidal portion will be at least twice as thick as the material in the cylindrical portion surmounting the discoidal portion.

Reasonable variation and modification are possible within the scope of the foregoing disclosure and the drawings, the essence of which is that we have provided a closure of resilient material having a thickened discoidal stopper portion and an outer depending skirt portion for effecting a reliable double seal of a container opening.

We claim:

1. A one-piece container closure of resilient material comprising a discoidal portion, a generally cylindrical wall portion extending upwardly from the periphery of said discoidal portion for insertion into the bore of a container opening, a radially outwardly extending annular portion attached to the top of said cylindrical portion, and a downwardly depending skirt formed of progressively thicker material in its downward direction and terminates at its lower extremity in an outwardly extending head of thickened material attached to the outer extremity of said annular portion, said discoidal portion being of relatively thickened material of substantially uniform thickness throughout said discoidal portion.

2. The closure of claim 1' wherein the tickness of said discoidal portion is at least twice the thickness of said generally cylindrical portion.

3. The closure of claim 1 in combination with a container provided with a bead at said opening, wherein said discoidal portion forms a tight seal within said bore and said depending skirt is adapted to seal tightly against the outside of said head.

4. The closure of claim 1 wherein said resilient mate'rial is a synthetic organic thermoplastic.

5. A container closure of resilient material comprismg:

(a) a discoidal portion, said discoidal portion being of relatively thickened material;

(b) a generally cylindrical wall portion extending upwardly from the periphery of said discoidal portion for insertion into the bore of a container opening, said generally cylindrical portion comprising a lower portion of outer diameter equal to the diameter of said discoidal portion, an inwardly extending ring portion surmounting said lower portion, and an upper portion above said ring having an inner diameter at least equal to the outer diameter of said lower portion;

() a radially outwardly extending annular portion attached to the top of said generally cylindrical portion at said upper portion; and

(d) a downwardly extending skirt attached to the outer extremeity of said annular portion.

6. The closure of claim in combination with a container having an opening with an inwardly disposed lip whereby said discoidal portion of said closure fits under said lip.

7. The closure of claim 5 in combination with a container provided with a bead at its opening wherein the discoidal portion of said closure forms a tight seal within the bore of said container and the depending skirt is adapted to seal tightly against the outside of the head at said opening.

8. A container closure of resilient material comprismg:

(a) a discoidal portion, said discoidal portion being of a relatively thickened material;

(b) a generally cylindrical wall portion extending up wardly from the periphery of said discoidal portion for insertion into the bore of a container opening;

(0) a radially outwardly extending annular portion attached to the top of said cylindrical portion; and,

(d) a downwardly extending flaring skirt attached to the outer extremity of said annular portion, said flaring skirt terminating at its lower extremity with a cylindrical portion having an inner diameter greater than the outer diameter of the lower terminus of said flaring skirt, said cylindrical portion on said flaring skirt being provided at its lower extremity with an outwardly extending annular bead whereby said closure is grasped for removal from a container.

9. A closure according to claim 8 wherein said generally cylindrical wall portion comprises a lower portion of outer diameter equal to the diameter of said discoidal portion, an inwardly extending ring portion surmounting said lower portion, and an upper portion above said ring having an inner diameter at least equal to the outer diameter of said lower portion.

10. The closure of claim 8 wherein said closure is provided with a plurality of venting grooves around the periphery of said discoidal portion.

11. The closure of claim 8 wherein the generally cylindrical portion comprises in an upward direction from said discoidal portion toward said radially outwardly extending annular portion, a first inwardly and upwardly tapering portion, and a second outwardly and upwardly tapering portion.

12. A container closure according to claim 8 provided with a stacking ledge on the exterior of said flaring skirt at the top of said cylindrical portion and further wherein said depending skirt is formed of progressively thicker material in its downward direction and terminates at its lower extremity with an outwardly extending head of thickened material to provide reinforcement for grasping to remove the closure from a container.

References Cited UNITED STATES PATENTS 1,619,509 3/1927 Groves 215-38 1,710,363 4/ 1929 Kramer 220-24 2,286,070 6/1942 Doe 215-38 2,808,957 10/ 1957 Bradley 220-24 2,922,563 1/ 1960 Aldington 220-97 XR 2,934,232 4/1960 Pesch et al. 215-41 3,263,724 8/1966 Mojonnier et al. 215-41 XR 3,335,901 8/1967 Edwards 220- 3,343,698 9/1967 Anderson et al. 215-38 XR DONALD F. NORTON, Primary Examiner U.S. Cl. X.R.

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