Tamper-proof Closure Arrangement

Abstract

A tamper-proof seal is located between a container and a cap received on a threaded open end of the container. The seal comprises a plurality of flexible ears integral with and distributed about the perimeter of the neck of the container and extending outwardly therefrom, then upwardly and then inwardly to provide a locking arrangement with a bead on the rim of the cap. The seal has a frangible portion to permit removal of the ears from the neck of the bottle.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of my copending application Ser. No. 182,073, filed Sept. 20, 1971, now U.S. Pat. No. 3,716,162, issued Feb. 13, 1973.

Description

BACKGROUND OF THE INVENTION

The use of tamper-proof seals between containers and caps has become increasingly prevalent in numerous industries in recent years because of the substantial losses that have been incurred while products are being displayed for sale. Examples of such devices are shown in Hogg U.S. Pat. No. 1,908,245; Merolle U.S. Pat. No. 2,062,271; and Cheeley U.S. Pat. No. 3,511,402.

Devices of the character disclosed in the above patents, while partially solving the problem of unauthorized removal of caps or containers, have several serious drawbacks. Tamper-proof seals of this type require a modification of the container and the cap as well as a separate element to provide an interlock between the container and cap. For example, the three patents referred to above, all require a separate band of metal or other material that is applied over enlarged cooperating flanges on the container and the cap to provide the tamper-proof seal. Such an arrangement is not only expensive in the initial manufacture of the container and closure, but also has inherent additional problems that increase the cost of filling the containers and sealing the cap to the container since they require a separate step for placing the tamper-proof band onto the container and cap after the filling and closure operations have been completed.

Another problem encountered with tamper-proof seals of the above type is that the containers and caps can be reused by applying a new tamper-proof band. In many areas, such as the milk industry, sanitation requirements dictate that the container be designed so as to be truly non-refillable. With devices of the above type, the containers can readily be reused any number of times.

While efforts have been directed towards the design of truly non-fillable containers with a tamper-proof seal, as evidenced by U.S. Pat. Nos. 3,088,617; 3,224,616; and 3,504,818, such devices have not found any degree of commercial success because of the manufacturing and assembly problems and/or number of parts that are required.

In my U.S. Pat. No. 3,716,162, referred to above, there is disclosed an improved tamper-proof seal for an open-ended container in which a flange integral with the container and adjacent its open end defines an upwardly opening recess with a reduced mouth at its upper end. The flange is divided into a fixed portion and a flexible, frangible portion. As a screw cap, with a skirt having an enlarged bead at its lower end, is threaded onto the open end of the container the enlarged bead, being larger than the mouth of the flange, causes outward deflection of the flangible portion so that the lower end of the skirt passes through the reduced mouth, causing the enlarged bead and the reduced mouth to serve as interlocking elements when the cap is placed in sealing engagement with respect to the open end of the container.

The closure described in said U.S. Pat. 3,716,162 is advantageous over the prior art tamper-proof closures in that it permits containers to be filled without any change in the filling line operation. However, because of the undercut geometry of the flange in said closure it is difficult to fabricate containers with such closures by high speed blow molding techniques. The manufacture of plastic bottles by conventional blow molding involves the closing and opening of mold sections about a parison, or gob, of molten or softened plastic, operations which do not permit mold cavities to be formed with substantial undercut portions. In accordance with the present invention, a closure is provided which maintains the advantages of the closure of said U.S. Pat. NO. 3,716,612 but which is nevertheless more readily fabricatable by high speed methods.

SUMMARY OF THE INVENTION

The present invention is a modification of the invention described in my U.S. Pat. No. 3,716,162, and similarly contemplates a tamper-proof seal between a container and a closure that requires only a modification of the container so that a conventional commercially available cap can be utilized with the container and the container can be filled and the closure applied thereto by well known filling and closure operations.

In place of the single flange of said U.S. Pat. No. 3,716,162, the container modification of this invention consists of a plurality of ears that are molded integral with the plastic container, each having an outwardly directed first portion, an upwardly directed second portion and an inwardly directed third portion adjacent the upper end of the second portion to define an upwardly opening recess having a reduced opening at its open end between the tip of the ear and the neck of the bottle. The inwardly directed third portion or wall has an interlocking element defined by a downwardly directed lip that cooperates with an interlocking element in the form of an enlarged bead on the bottom end of the cap so that a tamper-proof seal is created as the cap is threaded into sealing engagement with the open end of the container. The outwardly directed first portion of the ear has a weakened section that provides a frangible connection between the neck of the bottle and the first portion of the ear. In the preferred modification of the invention the ears are connected to each other by a bead of sufficient dimension to permit all the ears to be torn off the bottle neck in a single sustained motion when the seal is broken.

When the arrangement of the closure of this invention the cap can be inserted onto the container with a conventional type of closure machinery and the tamper-proof seal will automatically be provided between the cap and container.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF DRAWINGS

FIG. 1 is a plan view of a container and cap in the assembled condition;

FIG. 2 is a fragmentary elevation of the container and cap shown in FIG. 1;

FIG. 3 is a vertical section through the cap and the upper end of the container showing the cap as it is being assembled onto the container;

FIGS. 4 and 5 are fragmentary sections along planes 4--4 and 5--5 of FIG. 1, respectively; and

FIG. 6 is a plan view of another embodiment.

DETAILED DESCRIPTION

While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will herein be described in detail two specific embodiments, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.

FIGS. 3 and 4 of the drawings show a portion of a container 10 having an open upper end 12 with an external thread 14 on the periphery of the container adjacent the open end that receives a cap 16. The cap or closure 16 has a circular portion 18 with a sealing member 20 secured therein and a depending skirt 22 that has a cooperating thread 24 defined therein.

According to the present invention, the tamper-proof seal 30 is formed integral with the container 10 and comprises a plurality of ears 31 which cooperate with the closure or cap 16 to automatically interlock the container and cap as the cap is threaded into a sealing engagement with the open end 12 of the container. Furthermore, the cap may be of a conventional, commercially available type that can be assembled onto the container utilizing conventional assembly techniques. Each ear of the tamper-proof seal has a first outwardly directed substantially fixed portion 32 that is integral with the wall of the container and a second upwardly directed portion 34 with an integral inwardly directed third portion 36 along the upper end of the second portion. The first, second and third portions of the ear cooperate to define an upwardly opening recess 38 that is adapted to receive the lower end of the skirt 22 of the cap 16. In addition, the inwardly directed third portion 36 of the ear is of reduced cross section on the free end thereof to define a downwardly directed lip 40 that terminates adjacent the periphery of the container to define a reduced area opening or mouth for the recess and an undercut portion or groove 41 in the third portion or wall.

The first portion has a groove 42 that defines a frangible connection between the bottle neck and the first portion of the ear. The groove 42 also provides a flexing connection between the bottle neck and the first portion of the ear but has sufficient rigidity to maintain the portions in a predetermined position when no external forces are applied thereto.

Between ears 31, as best seen in FIG. 5, there is a relatively small bead 43 separated from the neck of the bottle by groove 42. The bead 43 is small enough and resilient enough so that the undercut portions of the mold corresponding to groove 42 can be removed from the formed container without difficulty, but it is strong enough to connect all of the ears to each other and hold them in a strip when the ears are removed.

As was indicated above, cap 16 is of a conventional, commercially available type that is normally formed of metal and has the free end of the skirt 22 curled outwardly to eliminate any sharp edges. This outwardly directed curl or bead 50 is utilized as one interlocking element that cooperates with the inwardly directed lip 40 to produce interlocking means between the container and the cap as the cap is threaded on the container. As more clearly shown in FIG. 3, the bead or enlarged portion 50 on the lower end of the cap has a transverse dimension which is greater than the mouth or opening for the recess 38 that is defined by the inwardly directed lip 40. With this arrangement, the threading of the cap on the container after a filling operation will cause the enlarged portion or curl 50 to be forced into opening 38. Since the opening on the upper end of the recess is of a dimension substantially less than the transverse dimension of the enlarged portion, the threading action or axial movement of the cap relative to the opening will cause an outwardly deflection of the free end portion of the ear to the position shown in FIG. 3. Continued rotation of the cap relative to the container will locate the enlarged bead 50 below the inwardly directed lip and when the cap is in sealing engagement with respect to the open end 12 of the container 10, the elastic memory of the plastic ear will return the first, second and third portions of the ear to their initial positions shown in FIG. 4. An inspection of FIG. 4 reveals that in this position the inwardly and downwardly directed lip 40 is positioned above the enlarged bead and the bead is received in the groove 41 and cooperates therewith to prevent removal of the cap without destroying the frangible seal.

When the purchaser desires to remove the cap, tab 60 integral with the second portion 36 of one ear 31 is utilized for severing the frangible connection incorporated into each ear. As each ear is severed, bead 43 interconnecting the ears is also torn and serves to begin tearing action for the next ear. After all ears are removed, it is impossible to reposition the frangible portion onto the remainder of the container which insures that the container will not be reused.

To insure that the bead or enlarged portion 50 enters the recess 38 with a minimum of force applied thereto, it is also desirable to have cooperating camming surfaces on the wall or third portion 36 and the bead 50. These surfaces are identified as arcuate surface 62 and 64.

It is to be noted that the arcuate surface 64 is shaped to produce an expansion of the opening or mouth for recess 38 as the cap is screwed into position on the container. In contrast, lip 40 is shaped to prevent expansion of the opening or mouth when the cap is unscrewed or moved upwardly and thus rupture of the seal is required to remove the cap.

In the embodiment of FIGS. 1 to 5 the closure has four ears evenly spaced about the neck of the container with the spaces between the ears being at least as wide as the ears, themselves. This arrangement permits several modes of fabrication which cannot be used for the closure arrangement of my earlier patent.

In one method of fabrication, each of the two mold halves has segments corresponding to two ear portions and two between-ears portions of the closure seal. Each of the ear portions of each mold half is shaped to correspond to the outer surfaces of each ear and each of the between-ears portions is shaped to correspond to bead 43 and groove 42. The mold is designed so that upon closing of the mold halves a telescoped projection emerges from one side of each between-ears portion to project into the space of an ear portion and to correspond to the undercut portion of recess 38. Upon opening of the mold halves, the projection, being spring-mounted retracts into the between-ears portion and presents no obstacle to the withdrawal of the container from the mold.

In another method of fabrication, each mold half has segments corresponding to two ear portions and two between-ears portions of the closure seal. The ear portions in this instance are shaped to correspond to the ears of the closure seal, including their undercut portions. Upon completion of the molding process and before separation of the mold halves, the container is rotated 45.degree. about its vertical axis so that each ear portion of the closure seal corresponds to a between-ears portion and the mold halves can thus be separated.

The closed mold has a threaded portion corresponding to thread 14 of the container, and the threaded portion of the mold moves the container axially downwardly to some extent when the container is rotated by 45.degree.. Because of this, portions of the mold corresponding to the undersurface of portions 32 of each ear are spring-mounted upwardly to permit some downward movement when the container is rotated.

FIG. 6 illustrates another embodiment of the invention, generally similar to the embodiment of FIGS. 1 to 5, but having only two ears 31a instead of the four ears of FIGS. 1 to 5. In this case, the container can be molded from two mold halves, each having end segments corresponding to half-widths of each ear. Because of the limited width of the ears of the FIG. 6 embodiment and the flexibility of the material of the container, e.g., polyethylene, the mold halves can be readily separated after the container is formed despite the undercut portions below each ear.

While the invention has been described in connection with a threaded cap, the invention is equally applicable to nonthreaded cap such as a press-fit or push-on cap. The material for the container may be any flexible plastic but polyethylene is preferred.

The tamper-proof seal provides a simple and inexpensive expedient for sealing the cap to the closure and gives an indication of whether the cap has been removed since the filling operation has taken place. All of this is accomplished with only a small additional amount of plastic material and a redesign of the plastic container without the need for separate additional elements. Also, the container having the tamper-proof seal can be used on existing filling lines for non-tamper-proof containers without modification of the filling line.

Claims

I claim:

1. In a container having an open upper end and a neck therebelow and having a cap to cover said open end while extending over the outer perimeter thereof, tamper-proof means comprising a plurality of flexible ears integral with and distributed about the perimeter of the neck of said container, extending outwardly therefrom and defining with said neck and upwardly opening recess about said neck, said tamper-proof means having a frangible portion whereby said ears may be removed from said neck, said ears and said cap having interlocking elements that engage each other when said cap is placed in sealing engagement with said open upper end to prevent removal of said cap without separating said frangible portion from said container.

2. The combination as defined in claim 1, in which said frangible portion has an upwardly and outwardly directed camming surface along the upper portion to guide the interlocking element on said cap into said recess.

3. The combination as defined in claim 1, in which said interlocking elements include an inwardly directed wall adjacent the upper end of said frangible portion defining a reduced area opening for said recess and an enlarged portion on the lower end of said cap having a dimension greater than the dimension of said opening, said frangible portion being temporarily deflected during threading of said cap onto said container to allow said enlarged portion to be received into said recess below said wall.

4. The combination as defined in claim 3, further including cooperating camming surfaces on said wall and said enlarged portion to cause outward deflection of said frangible portion when said cap is threaded on said container.

5. The combination as defined in claim 1 wherein tamper-proof means comprises four flexible ears of equal width separated by spaces at least as wide as said ears.

6. The combination as defined in claim 5 wherein a bead extends from the neck of said container in each of said spaces between said ears, said bead being connected to the ears on either side of each of said spaces.

7. The combination as defined in claim 1 wherein said tamper-proof means comprises two flexible ears of equal width separated by spaces wider than said ears.