EP0771290A1

EP0771290A1 - Tamper-evident closure system

Info

Publication number: EP0771290A1
Application number: EP94919421A
Authority: EP
Inventors: Sheldon Wilde
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-06-08
Filing date: 1994-06-08
Publication date: 1997-05-07
Also published as: EP0771290A4; PL174528B1; WO1994029186A1; JPH10500650A; AU7057794A; HUT76599A; PL317607A1; AU691184B2; HU9603381D0

Abstract

An inexpensive, multi-component closure for both pressurized and vacuum-packed containers (60), includes a closure disk (400) having a combination of features for forming an effective seal for the open mouth of such containers (60) and a screw cap (412), also with a combination of features, for carrying, by its rotation, the closure disk (400) into closing and sealing engagement with the open mouth (61) of the container (60). The closure disk (400) and screw cap (412), through their coaction, provide tamper evidence upon any subsequent counter-rotation of the screw cap (412), for example, as a user initiates opening of the container (60). Through their coaction, closure disk (400) and screw cap (412) also maintain an effective seal by controlling compression set of the seal, even if the closure is exposed to heavy top loads for long periods, such as in storage, and the subsequent removal of the load.

Description

TAMPER-EVIDENT CLOSURE SYSTEM

Technical Field

The present invention relates generally to tamper-evident closures, and more particularly to a new multi-component, tamper-evident closure particularly applicable to pressurized and partially evacuated containers, such as those used to contain carbonated beverages and vacuum-packed foods, and still more particularly to a new two-component cap arranged to maintain an effective seal and to provide tamper evidence from engagement with a container.

Background Art

Basic bottle caps for carbonated beverages have included cork and plastic liners and, metal fluted caps which are crimped around the radiused lip of a glass bottle. More recently, bottle caps have included a plastic or metal cap with a frangible ring which cooperates with the bottle neck to interlock the frangible ring and hold it in position while the upper cap portion twists free. Such bottle cap structures include a number of patented designs and some of the applicable patents are set forth hereinafter.

Listed below are a number of patents which are directed to closures, some of which disclose closures including an inner disk-element having a sealing liner and an outer plastic cap. Other listed references disclose multi-component tamper-evident designs.

Issued

06/02/08 05/17/10 06/14/27 08/03/37 03/19/40 05/27/69 Patent No. Inventor Issued

3,836,033 Podesta 09/17/74

3,974,928 Domaracki, et al. 08/17/76

4,473,163 Geiger 09/25/84

4,564,117 Herbert 01/14/86

4,640,428 Chang 02/03/87

4,721,219 Dullabaun, et al. 01/26/88

1,755,168 Carvalho 04/22/30

2,131,774 Waring 10/04/38

2,131,775 Waring 10/04/38

2,414,420 Sebell 01/14/47

2,560,793 Greene 07/17/51

2,939,597 Greene 06/07/60

4,220,250 Brownbill 09/02/80

4,446,979 Gach, et al. 05/08/84

4,505,399 Weiner 03/19/85

4,531,649 Shull 07/30/85

4,576,297 Larson 03/18/86

4,706,828 Zinnbauer 11/17/87

4,722,447 Crisci 02/02/88

4,747,500 Gach, et al. 05/31/88

4,801,028 Puresevic, et al. 01/31/89

Patent No. Country

1.068.346 French

523.527 Belgium

1 289 508 United Kingdom

1 087 035 German

Some of the above-listed references show that it is well-known to provide a closure including an inner disk having a container-engaging liner element and an outer screw cap for retaining the disk in position. Typically the liner element is secured to the lower face of the disk for engagement with the top of an associated container finish. Screw threads secure the outer plastic cap onto the container finish and advancement of the outer plastic cap onto the container advances the disk and the liner into sealing engagement with the container finish.

Other of the listed references disclose tamper- evident features, some of which include the provision of one or more breakable or frangible elements arranged in the top wall of the outer closure cap. The patents listed above are only part of the many issued patents having similar and related teachings. Notwithstanding the many issued closure patents, a need still exists for a closure that can be inexpensively manufactured, applied to both pressurized and partially evacuated containers, and provide an effective seal by closure rotation and tamper evidence by a subsequent counter-rotation, and that can maintain its effective seal even with the imposition and release of heavy top loading, such as that experienced in storage and shipment. The closure art, notwithstanding its extensive development activity, has not previously succeeded in providing a closure meeting this severe combination of requirements.

Disclosure of the Invention

This invention provides an easily manufactured and inexpensive, multi-component closure for both pressurized and vacuum-packed containers, with first means having a unique combination of features for forming an effective seal for the open mouth of such containers and second means, also with a unique combination of features, for carrying, by its rotation, the first means into closing and sealing engagement with the open mouth of the container. The first and second means, through their coaction, provide tamper evidence upon any subsequent counter- rotation of the second means, for example, as a user initiates opening of the container.

According to the present invention, a closure for the mouth-forming top of a threaded container comprises a screw cap and a closure disk. The screw cap includes a top panel and a skirt with thread means for engaging the threaded top of the container. The top panel spans the mouth-forming top of the container and includes at least one tamper-evident panel portion, defined by a frangible portion of the top panel, and an actuating tab extending from the tamper- evident panel portion.

The closure disk includes an elastomeric seal carried at its periphery and a peripheral portion extending radially outwardly from said periphery into engagement with said screw cap. The closure disk is sized to close the mouth-forming top of the container at its periphery and to be carried by the screw cap under and adjacent the top panel, with its upper surface adapted to engage the actuating tab.

Upon the advancement of the thread means of the screw cap on the threaded top of the container, the closure disk is carried downwardly onto the mouth- forming top of the bottle and the elastomeric seal is compressed between said closure disk and the mouth- forming top of the container and forms a seal. The peripheral portion of the closure disk is deformed into engagement with the mouth-forming top of the container. When the closure disk is engaged with the mouth-forming top of the container by the screw cap, it provides a significant "non-rotative" force that resists relative rotation with respect to the container.

During the initial rotation of the screw cap in its removal from the threaded top of the container, the non-rotative force immovably retains the closure disk in sealing engagement with the mouth-forming top of the container. The resulting relative rotation of the screw cap with respect to the closure disk results in breaking the frangible portion of the top panel and actuating the tamper-evident panel portion of the top panel through the engagement of the actuating tab with the top surface of the closure disk.

In one preferred embodiment of the invention, the closure disk forms a plug carrying an elastomeric seal that is configured to extend into and engage the threaded top of the container. The amount of non- rotative force can be controlled by the interference between the plug and the threaded top of the container.

In another embodiment of the invention, the closure plug forms a resilient peripheral portion that is deformed by the screw cap as it is threaded onto the container top to provide thereby a controllable non-rotative force. Furthermore, the closure disk and screw cap each include load bearing portions which are moved into engagement with each other and with the container to thereby, in combination, transfer stacking loads imposed on the screw cap to the container without affecting the sealing engagement of the closure disk with the open mouth of the container. For example, the closure disk can include a compression controlling means, such as a compression rib, adjacent the seal-forming material, and the screw cap can include one or more load-bearing ribs bearing on the closure disk adjacent its compression controlling means and, through the closure disk, the container adjacent its open mouth.

In another aspect of the invention, the actuating tab extends downwardly from the tamper-evident panel portion and terminates in an engagement surface disposed to contact a portion of the upper surface of the closure disk. The actuating tab includes a first end attached to the tamper-evident panel portion and an intermediate portion extending downwardly from the first end at an acute angle to the tamper-evident panel portion. The engaging surface includes a frictional or adhesive material to contact the upper surface of the closure disk in order to resist relative movement between the actuating tab and the closure disk when the screw cap is removed from the container and to effect removal of the tamper-evident panel from the top panel of the screw cap.

The actuating tab can further include resilient means for urging the actuating tab into contact with the closure disk. The resilient means includes a curved second end connected to the intermediate portion, wherein the second end curves upwardly from the intermediate portion and is sized to be deformed between the closure disk and the top panel when the screw cap is advanced onto the threaded top. When the screw cap is advanced onto the threaded top, the second end urges engagement of the actuating tab with the top panel adjacent the tamper-evident panel portion.

The closure of this invention includes a number of other unique features such as new interrupted thread means, new preferential venting means and others, which through their coacting with each other and with the features of the first and second means that are described above, provide other advantages, all as shown and disclosed by the drawings, and the more detailed description and claims that follow.

Brief Description of the Drawings

Fig. 1A is a perspective view of a tamper-evident closure of this invention and a threaded mouth-forming part of a container to which it will be applied by rotation in the clockwise direction; Fig. IB is a perspective view of the tamper- evident closure of Fig. 1A after it has been applied to close the container and after it has been counter- rotated about 45° counter-clockwise and demonstrates the tamper evidence of the closure;

Fig. 2 is a perspective view at the closure of Figs. 1A and IB, exploded to show its first and second means adjacent a threaded mouth-forming part of a container;

Fig. 3 is a bottom view of a preferred first means of the invention;

Fig. 4 is cross-sectional view of the first means of Fig. 3 taken at a plane through the center of the first means;

Fig. 5 is an enlarged partial cross-sectional view of a peripheral portion of the first means of Fig. 3 taken at plane 5-5 of Fig. 3;

Fig. 6 is a cross-sectional view of a preferred second means of the invention taken at a plane through its center;

Fig. 7 is a view from the underside of the second means of Fig. 6;

Fig. 8 is a cross-sectional view of the closure of this invention formed from the assembly of the first means of Figs. 3-5 and the second means of Figs. 6 and 7, taken at a plane through its center;

Fig. 9 is a partial cross-sectional view of peripheral portion of the closure of Fig. 8, loosely threaded onto a container;

Fig. 10 is a partial cross-sectional view of a peripheral portion of the closure of Figs. 8 and 9 seated on a container;

Fig. 11 is a partial cross-sectional view of closure of the invention, without a resilient peripheral portion, on a vacuum-packed container; Figs. 12A and 12B are views from below a second means to demonstrate a method of assembly of the first and second means;

Fig. 13 is a partial perspective view of a frangible tamper-evident portion of a second means of the invention as it may be formed by injection molding;

Fig. 14 is a partial perspective view of the frangible tamper-evident portion of Fig. 13 to illustrate its scoring to provide frangibility;

Fig. 15 is a partial perspective view of portions of the frangible tamper-evident portion of Fig. 14 and of the first means to illustrate the removal of the tamper-evident portion;

Figs. 16 and 17 are, respectively, a bottom view of a first means of the invention and a partial cross- sectional view of a portion of the periphery of the first means of Fig. 16 (taken at plane 17-17 of Fig. 16) to illustrate one means for providing preferential venting of one portion of the closure periphery;

Figs. 18 and 19 are, respectively, a bottom view of a first means of the invention, and a partial cross-sectional view of a portion of the periphery of the first means of Fig. 18 (taken at plane 19-19 of Fig. 18) to illustrate another means for providing preferential venting at one portion of the closure periphery; and

Fig. 20 is a perspective view of another closure of the invention including venting passageways formed between the threaded skirt of its screw cap and an outer surface.

Fig. 21 is a section view of an alternative embodiment of the first means taken at a plane through the center of the first means; Fig. 22 is a bottom view of the alternative embodiment of the first means of the invention;

Fig. 23 is a cross-sectional view of a closure threaded onto a container and thereby retaining the first means in position;

Fig. 24 is a partial perspective view of an alternative embodiment of the frangible tamper-evident portion of a second means of the invention as it may be formed by compression or injection molding;

Fig. 25 is a partial perspective view of the frangible tamper-evident portion of Fig. 24 to illustrate its scoring to provide frangibility; and

Fig. 26 is a partial perspective view of the frangible tamper-evident portion of Fig. 24 and the first means to illustrate the removal of the tamper- evident panel and partial bending back of the tamper- evident panel

Best Mode For Carrying Out The Invention

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Figs. 1A, IB and 2 show a closure 50 of the invention and a partial view of a container 60 having a threaded mouth-forming part 62, which is frequently called the container "finish". As shown in Figs. 1A, the closure 50 of the invention includes a tamper- evident portion 250 at its top, the tamper-evident portion being shown as a plurality of frangible tamper-evident panels 251, which, before application of the closure 50 to the container 60 are an integral part of the closure. After the closure 50 has been threaded onto the container 60 the tamper-evident portion 250 of the closure 50 becomes activated, as described more fully below, and counter-rotation of the closure 50 to initiate its removal from the container results in removal of the frangible tamper- evident portions 251 from the top of the closure to provide tamper evidence, as shown by the darkened voids 201 of Fig IB where the frangible tamper-evident panels 251 were before the counter-rotation. The invention permits the demonstration of tamper evidence upon counter-rotation of the closure through angles as small as 10° to 30°.

Fig. 2 is a perspective view of a closure 50 of this invention above the container 60. The closure 50 is exploded to show its multiple components. As shown in Fig. 2, closure 50 includes a first means 100 for forming a seal of the open mouth 61 of container 60 and a second means 200 for carrying the first means 100 into closing and sealing engagement with the container 60 adjacent its open mouth 61. As shown in Fig. 1, container 60 includes threads 62 adjacent its open mouth 61, and the second means 200 includes a downwardly extending skirt portion 202 including thread means 211 formed on the internal surface 202a of the skirt portion 202 to mate with threads 62 of the container 60 and carry the first means 100 into closing and sealing engagement with the container by rotation of the second means 200 with respect to the container 60. While the container shown in Fig. 2 includes a simplified depiction of the continuous threads of the type formed on the finish of containers used for carbonated soft drinks, the invention can be used with containers including an interrupted, ramp-like threads of the type used on the finish of containers for baby foods and other vacuum packed food stuffs. While the closure 50 is illustrated as having continuous thread means for mating with the continuous threads typically used on carbonated beverage containers, it may include a skirt formed with a plurality of container engaging lugs to engage the interrupted, ramp-like threads of the containers used for vacuum packed foods. The tamper-evident feature provided by the invention upon the initial counter-rotation of a closure on a container, may be specifically designed for application on either type of container, that is, a container which is under pressure when filled, such as soft drink and beer containers, or a container which is under partial vacuum when in use, such as containers for baby foods, ketchup and the like.

Figs. 3-5 show a preferred embodiment of the first means of the invention and the features by which it forms both means for generating internally a seal- maintaining force and means for maintaining a seal notwithstanding intermittent top loading of the closure 50. The first means 100, as shown in Figs. 3- 5, preferably comprises a closure disk formed from inexpensive steel. Such steel has an ultimate tensile strength in excess of 100,000 psi and costs only about .50 cents per pound. The preferred steel is 55-pound base weight DR-9CA tin-free sheet steel. The steel is preferably coated with an inert coating such as a modified epoxy. As shown in Figs. 3-5, the closure disk 100 comprises a central panel 101 having a sufficient size to cover the open mouth 61 of the container 60 (see Fig. 2) . The central panel 101 of closure disk 100 may be provided with a slight spherical-like deformation (not shown) to ensure the flatness of the closure disk 100. Closure disk 100 is provided, in the invention, with a compression controlling means 102, in the form of compression rib 102, which preferably completely encircles the central panel 101 in the form of a downwardly extending annular ring 102. As shown in Figs. 3-5, an elastomeric sealing material 103 is carried by the closure disk 100 around the central panel 101 at the base of the downwardly extending annular compression rib 102. Where in this application I use the term "upwardly", I mean a direction extending upwardly from the mouth of the container; and where in this application I use the word "downwardly", I mean a direction extending downwardly onto or into the container.

The closure disk 100 further comprises a resilient peripheral portion 104 extending outwardly from the lower end of the compression rib 102 and terminating in a circular outer edge 104a. The outer diameter of the circular terminating edge 104a of closure disk 100 has a size to fit within and engage one or more disk carrying surfaces of the second means or screw cap 200, as described below. While the preferable first means includes, as its compression rib, a downwardly extending annular ring as shown in Figs. 3-5, the compression rib may be formed by a plurality of downwardly extending compression rib portions extending uniformly and spaced about the closure disk 100, and while Figs. 3-5 show the resilient portion 104 of the closure disk 100 as an annular peripheral portion extending outwardly from the compression rib 102, the resilient peripheral portion may comprise a plurality of peripheral portions extending outwardly from a plurality of compression ribs spaced and extending substantially uniformly around the periphery of the closure disk 100.

The compression rib 102 of the first means 100 provides two important functions in the closure 50 of this invention. The lower portion of compression rib

102 carries the elastomeric sealing material 103 into sealing engagement with the portion of the container finish forming the open mouth and bears against and seats on the top surface of the container finish when the closure 50 is applied to the container, as shown Fig. 10. As described in further detail below, when the closure 50 is applied to the container, the compression rib 102 carries and transfers forces and loads applied on the top of container 50 to the container 60 relieving the seal-maintaining material

103 of load bearing and substantially controlling compression set of the elastomeric seal-maintaining 103 as a result of loads applied on top of the closure 50. It is common practice that filled and closed containers are stacked one upon the other during storage and shipment, and this practice has led to uncontrolled compression set in the sealing materials of prior art closures during shipment and storage. When such containers, with sealing materials having a high degree of compression set, are subsequently unstacked for display in grocery stores and other outlets, or when stored in the home of a user, the sealing materials of the prior art closures which have a high degree of compression set frequently fail to maintain a seal and allow a release of the carbonation of the contained beverage, for example of soft drinks and beer, and in vacuum packed containers, the leakage of air into the container. The employment of a compression rib 102 in closures 50 of this invention substantially controls compression set in the seal material 103 and substantially maintains a seal under these adverse conditions.

Compression rib 102, through coaction with the resilient peripheral portion 104 also applies a seal- maintaining force to the seal material 103. As shown in Figs. 8-10, the second means, or screw cap 200, includes a surface 220 engaging the resilient peripheral portion 104, and when the closure 50 is screwed onto the bottle, as shown in Fig. 10, deforms the resilient peripheral portion 104 by bending its periphery 104a downwardly as the closure 50 is rotated onto the container 60 and after the compression rib 102 is seated on the top of the container, as shown in Fig. 9. Through the resilience of the steel of the preferred closure disk 100 of this invention and its reaction against the second means or screw cap 200, a force is generated internally within first means 100 urging the compression rib 102 downwardly, maintaining the compression of the elastomeric seal material 103 and thereby providing a seal-maintaining force within the closure. The seal-maintaining force is particularly advantageous when the closure 50 is used on pressurized containers, such as the large containers of carbonated soft drinks and beer, where the internal pressure within the closed container can reach pressures in the range of 90-100 psi. Pressures in the range of 90-100 psi in typical soft drink and beer containers generate a force on the order of 50-60 pounds acting upwardly on the underside of closure disk 100 and against the seal material 103. In preferred designs of the closure of my invention, the closure disk 100 can generate a seal-maintaining force about twice the force acting from within a closed container which tends to unseal the container.

The preferred first means 100 of the invention thus includes means for maintaining a container seal in the presence of forces supplied downwardly on the top of the closure 50 and forces applied upwardly from within the container 50. In the preferred closure disk 100 shown in Figs. 3-5 such composite means are simply formed outwardly of the central panel 101 closing the open mouth of the container by a downwardly extending compression rib 102 and a resilient peripheral portion 104 extending outwardly from the compression rib 102. The compression rib 102 may extend downwardly from the plane of the closure disk about 0.02 to 0.03 inches. The preferred closure disk 100 of my invention can be easily formed by blanking and forming dies which can rapidly produce the preferred disks from coated steel about 0.006 inches thick, or other substantially resilient sheet material. It should be noted that while the preferred closure disk of my invention includes features permitting its applicability to both pressurized and vacuum formed containers, the use of the resilient peripheral portion 104 is unnecessary for vacuum filed containers, as shown in Fig. 11.

Figs. 6 and 7 show a preferred embodiment of the second means 200 of the closure 50 of my invention. As shown in Fig. 6 and 7, the second means preferably forms a screw cap 200 which includes a number of novel features.

As indicated in Figs. 6 and 7, a preferred screw cap 200 includes a top panel 201 including a portion 250 providing tamper evidence, internal means 221 adapted to engage and carry the first means or closure disk 100, internal load bearing means 230 to carry and transfer loads applied downwardly on the top panel of

201 to the container, and a downwardly depending skirt

202 including an internal thread means forming an interrupted thread for engagement of the threads formed on the container finish.

As illustrated in Fig. 12A the skirt portion 202 of the preferred screw cap 200 of my invention may be deformed from its circular configuration, as shown in Fig. 12B, to a somewhat triangular configuration to move a plurality, preferably three, tabs 204 (which form surfaces 221 adapted to engage and carry the closure disk 100) outwardly from the screw cap center, permitting closure disk 100 to be inserted into the cap, and upon release of the deformation and return of the skirt portion 202 to its original shape, surfaces 221 of tabs 204 engage and carry the closure disk 100 within screw cap 200, as shown in Fib. 13. Such a method of engaging the first and second means is made substantially easier by the interrupted thread means 210 of the skirt 202, which are described more fully below. In another embodiment (not shown) , the internal surface of the second means may be provided with a plurality of resilient tabs to carry the first means upon its assembly into the second means. The resilient tabs can be of such size and thickness that they are easily deformed by the closure disk 100 as it is pressed into the second means and, upon passage of the closure disk 100, return, through their resilience, to substantially their original position maintaining the assembly of the first and second means. For example, four thin locking tabs which are not necessarily equally spaced may be joined to the inside surface 202a at an approximate 20 degree angle. This 20 degree angle combined with the thin triangular shape of the tabs creates an easy assembly step in order to locate the closure disk 100 above the upper surfaces of the four tabs and below disk-locating surfaces 220, 230 of the screw cap. As the closure disk is pushed upwardly against the four thin tabs 204, the forces which are applied to the projections can cause the thin tabs to deflect sideways toward inside surface 202d. As this movement of the projections occurs, the clearance space increases and the closure disk is able to pass by the thin tabs. Once the disk is pushed past the thin tabs, the deflecting force on each of the thin tabs is relieved and the thin tabs then flip back to their beginning position so as to provide lower carrying surfaces for the closure disk 100.

As noted above, one of the features of the invention is a novel interrupted thread means 210 formed on the internal surface of the skirt 202. As shown in Fig. 6, a preferred container screw cap 200 of this invention includes a top panel 201 and a downwardly depending skirt 200 with a novel internal thread engaging surface 212a. As shown in Fig. 6, the internal thread means 210 forms a thread-engaging surface by a plurality of narrow projections 211 extending from the internal surface 202a of the skirt 202. Each of the narrow projections 211, includes an exposed surface 211a. The plurality of narrow projections 211 are arranged serially with their exposed surfaces 211a being serially arranged to form the internal thread engaging surface of the skirt 202. As further shown in Fig. 6, the skirt further forms a reinforcing rib 212 extending from the internal surface 202a of the skirt 200 between and interconnecting each of the plurality of narrow projections 211 at their junctures 211b with the internal surface 202a of the skirt 202. Preferably, as shown in Fig. 6, the reinforcing web 212 extends from the internal surface 202a only part of the distance from the junctures 211b of the plurality of narrow projections to their thread engaging surfaces 211a.

In preferable closures of the invention, the skirt forms from about 8 to about 10 narrow projections per inch of thread length, and each narrow projection has a width in the range of about 0.03 to about 0.05 inches. The thread enforcing rib 212 adds hoop strength to the skirt 202 and the thread means 210, and may be formed preferably with a thickness of about 0.02 to 0.04 inches and an extension from the internal surface 202a of the skirt 202 a distance of about 50 to 60 percent of the maximum distance from the junctures of 211b of the plurality of projections 211 to the inner most portion of their thread engaging surfaces 211a. Another feature of the novel interrupted thread means 210, is that the uniform narrow projections 211 forming the thread means 210 eliminate thick sections of the screw cap which are in slow cooling when the screw cap is injection molded, and the thread means 210 cools more rapidly and more uniformly so that injection molded screw caps 200 with such threads can be removed from the tooling more quickly. The interrupted threads formed on the skirt of 202 of the second means provide a pathway for gas when the sealing engagement of the first means, or closure disc 100, is broken.

As shown in Figs. 6-8, second means 200 includes at least one and preferably a plurality of internal surface portions 220 and 230 to engage and locate the first means 100 within the second means 200. In addition, the second means 200 includes at least one and preferably three internal tabs 204 for carrying the first means within the second means as shown in Figs. 12 and 13 and described above. As also shown in Figs. 6-10, the second means 202 also includes at least one and preferably a plurality, e.g. three, load bearing ribs 230 extending downwardly from the underside of the top panel 201. While ribs 230 are shown in the figures as comprising separate projecting internal surface portions, a continuous, uninterrupted internal rib will perform the equivalent function and prove suitable for use with this invention. The load bearing ribs 230 of the second means and the compression rib 102 of the first means 100 form compression controlling means that cooperate to transfer loads applied to the top of the closure 50 to the container 60 and to relieve the elastomeric seal material 103 from such loads that can form an uncontrolled compression set in the seal material 103 and lead to a loss of the container seal.

As noted above, an important feature of the invention is the means by which it provides tamper evidence. In the preferred closure of the invention the top panel 201 of the second means 200 includes preferably a plurality of frangible portions 251, such as the four shown in Fig. 1A and 7. As shown in Fig. 7 and more clearly indicated in Fig. 13, which is a perspective view of a frangible tamper-evident portion

250 of the second means 200, the tamper-evident portion 250 includes at least one tamper-evident panel

251 (preferably four) and each tamper-evident panel further comprises an actuating tab 251 extending downwardly from the tamper evident panel 251 for engagement by the first means 100 when the second means 200 has carried the first means 100 into sealing engagement with the container as shown, for example, in Fig. 10. In the preferred closures of the invention, the first means 100 comprises an upper surface carrying a contact adhesive, shown as 100a in Figs. 4 and 5, and the underside of actuating tab 251 also carries a cooperating contact adhesive 252a (Fig. 14) into engagement with the adhesive 100a on the upper surface of the first means 100 when the second means has carried the first means into sealing engagement with the container.

The actuating tabs 252 are provided, preferably, with side rails 252b to control the actuating thickness of the adhesive 252a applied to the actuating tab 252. As further indicated in Figs. 8 and 9, the internal tabs 220 and 230 of the second means 200 provide locating surfaces for the first means 100 and prevent engagement of the actuating tab

252 with the upper surface of the first means 100 until after rotation of the second means has carried the first means into closing and sealing engagement with the container.

As shown in Figs. 13-15, the actuating tab 252 extends from the tamper-evident panel 251 of the second means 200 in the direction of rotation as a second means 200 is threaded onto the container.

The actuating tab 252 also includes a fulcrum- forming portion 252c that extends from the upper surface of the actuating tab 252 to bear against the lower surface 201a of the second means 200 so that the tamper-evident 251 panel is pulled downwardly from the top 201 of the second means by the first means 100. As shown more clearly in Fig. 13, the tamper-evident panel 251 is defined by a segmented frangible portion

253 including segments 254-257 of reduced top panel thickness. As shown in Fig. 14, the segments of reduced thickness are, after molding of the screw cap, scored, at 254a, 255a, 256a and 257a so that the tamper-evident panel 251 is retained in the top panel 201 by only a plurality of spokes of material 260-263 to control the force required to tear the tamper- evident panel 251 from the top panel 201 of the screw cap. Thus, after the top panel 201 of the screw cap has been scored, each of the frangible panels 251 are held in place by the body of the top panel 201 remaining between the scored segments in spoke-like form, shown as spokes 260-263 as shown in Fig. 14.

Fig. 15 illustrates the tamper-evident panel 251 torn from its position in the top panel 201 by breaking of the spoke portions 260-263. In Fig. 15 the top panel 201 of the second means 200 has been counter-rotated in the direction drawn by arrow 275 and the first means 100 (shown only partially in Fig. 15 for clarity) has remained stationary on the container as described above. Because of the adhesive engagement of the actuating tab 252 and the first means 100, segments 260-263 (Fig. 14) have been broken and the actuating tab 252, through the coaction between fulcrum-forming portion 252c and the top panel 201, has removed the tamper-evident panel 251 from the top panel 201 of the second means 200 to provide tamper evidence as shown in Fig. IB.

As described above, the several internal portions of the screw cap 200 provide dual functions. The tabs 220 and 230 prevent engagement of the top surface of closure disk 100 with the actuating tabs 252 of the tamper-evident panels 251 until the closure 50 is screwed onto a container. The tabs 220 also deform the resilient peripheral portion 104 of the closure disk 100, and the tabs 230 seat on the closure disk 100, adjacent compression rib 102, and on the container top to transfer loads applied to the closure top of the container.

Thus, as shown and described above, a preferred container closure 50 of this invention includes a screw cap 200 including a top panel 201 and a skirt 202 with thread means 210 for engaging the threaded top 62 of the container 60. The top panel 201 spans the open top of the container and includes at least one, and preferably a plurality of tamper-evident panel portions 251 defined by frangible segments 260- 263 of the top panel 201. The closure of the invention further includes a closure disk 100 sized to close the open mouth 61 of the container 60 at its periphery which is carried by the screw cap 200 under and adjacent top panel 201 with its upper surface adapted for and in position to engage the actuating tabs 252 extending downwardly from under the tamper- evident panel portions 251 when the closure 50 is applied to a container. The closure disk 100 includes an elastomeric seal 103 carried at its periphery and a compression rib 102 and a resilient peripheral portion 104 extending radially outwardly from the compression rib 102 into engagement with the screw cap 200.

The screw cap 200 includes as shown in Figs. 8- 10, surfaces 220 and 230 which engage the first means 100 as the screw cap 200 is screwed onto the container 60. The compression rib 102 of the screw cap is advanced downwardly into engagement with the closure disk 100 immediately adjacent the compression rib 102 as shown in Fig. 9 to provide, with the tabs 230, a compression controlling means to control compression set of the elastomeric seal material 103.

Upon further advancement of the thread means 210 and the screw cap 200 on the threaded top 62 of the container 60 the closure disk 100 is carried downwardly onto the top 62 of the container 60 as shown in Fig. 10. The elastomeric seal 103 is compressed between the compression rib 102 of the closure disk 100, and the mouth-forming top of the container, as shown in Fig. 9 and 10, to form a seal. The compression rib 102 of the closure disk also seats on the mouth-forming top of the container 60 to transfer loads supplied to the top of the screw cap 200 to the container and to limit the further compression of the elastomeric seal 103. The resilient peripheral portion 104 is deformed by its engagement with the tabs 220 of the screw cap 200, and, through its deformation and by its engagement with the screw cap 200, generates a seal-maintaining force on the elastomeric seal 103 of the closure disk.

When an attempt is made to unscrew the screw cap 200 from the threaded top 62 of the container 60, the closure disk 100 is immovably restrained in sealing engagement with the mouth-forming top of the container 60 by engagement of the elastomeric seal 103 with the top of the container and by the seal-maintaining force generated by the closure disk 100. The resulting relative rotation of the screw cap 200 with respect to the closure disk 100 results in breaking the frangible portions 260-263 of the top panel 200 and actuating the tamper-evident panel portions 251 through the adhesive engagement of their actuating tabs 252 with the top surface of the closure disk 100 (as shown in Figs. IB and 15) .

As is noted above, the actuating tabs 252 of the second means 200 are maintained out of contact with the upper surface of the first means by one or more locating surfaces 220, 230 formed on the under side of the second means, and as the closure 50 is threaded onto a container, the actuating tabs 252 are moved into adhesive engagement with the first means. Any adhesive system may be used that creates adhesion of the actuating tabs 252 to the upper surface of the first means as the actuating tabs 252 are forced into contact with the first means. For example, adhesive 100a may be applied to the upper surface of the first means 100 as described above and/or may be placed upon the underside of the actuating tabs 252 themselves. One such adhesive system is a hot melt material sold by the Eastman Company by their No. 728S Hot Melt, but any contact adhesive may function in this application provided it develops sufficient adhesive force to break the frangible portions 260-263 of top panel 201 and remove the tamper-evident panels 251. Two-part adhesives may also be used, with one part of the two- part adhesive being applied to the top surface of the first means 100 and the second part of the two-part adhesive being applied to the actuating tabs 252 so that when they are brought into contact the adhesive may become catalyzed and set to join the actuating tabs 252 to the first means 100.

As further noted above, the actuating tabs 252 extend in the direction of the rotation of the screw cap as it is threaded onto the container, and as shown in Figs. 13-15, the forces imposed on the frangible peripheral portions 260-263 of the frangible tamper- evident panels 251 do not act to tear the frangible peripheral portions 260-263. Capping heads in use in the bottling industry have a flat rigid surface that bears down on the entire top surface of a cap as it is screwed onto the bottle finish. The closure of the invention uses the engagement of the top panel 201, and its tamper-evident portion or portions 251, with the flat rigid surface of the capping head to prevent the tamper-evident panels 251 from being torn or dislodged from the top panel 201. As the screw cap 200 is placed on the container, any relative motion between the top panel 201 and actuating tabs 252 and the fasteners or closure disk 100 in the opposite direction to that shown as 275 in Fig. 15, and any force imposed on the tamper-evident panels 251 by the actuating tabs 252 will be in a direction upwardly, rather than downwardly as illustrated in Fig. 15. The downward force applied to the tamper-evident portions 251 of the screw cap 200 by the capping head will prevent movement of the tamper-evident portion 251 upwardly out of position during capping.

When the screw cap is turned in a direction to unthread it from the container the forces imposed on the frangible peripheral portions 260-263 of the tamper-evident panel 251 by the actuating tabs 252 tear the unscored and unsevered portion, or spokes, 260-263 and remove the tamper-evident panels 251 from their place in the top panel 201 of the screw cap 200. To provide further clear evidence of the tampering with the container, the top surface of the first means 100 may be coated with a bright color which contrasts with a white color for the molded screw cap 200.

As shown in Figs. 16-17, the first means 100 may also include means to provide preferential venting of gas into and out of the container at one portion 110 of the periphery of the first means. For example, the thickness of the elastomeric seal material 103 of the first means 100 may be reduced over a preferential venting portion 110 of the first means 100 thereby providing a lesser seal at one portion 110 of its periphery. In addition to, or in place of, the reduced thickness of the seal material, the first means 100 may be provided with additional seal- maintaining material 103a adjacent one side 110' of its periphery as shown in Figs. 18 and 19, so that when the screw cap 200 is unthreaded from a pressurized container the internal compression force lifts preferentially the side of the closure disk 100 opposite the additional seal-maintaining material 103a. For example, a bead of hot melt may be applied in the 45° sector 110' of the periphery of the resilient peripheral portion 104 of the first means 100 where it is forced by deformation of the resilient peripheral portion 104 into engagement with the mouth- forming portion of the container as the closure 50 is threaded onto the container 60.

As noted in Figs. 14 and 15, the frangible portion, or spokes 260-263 are located outside of the actuating tab(s) 252 so that the top panel 201 of screw cap 200 may be supported from inside while the preformed channels 254-257 may be scored from above the screw cap as shown at 254a-257a, leaving only the plurality of ribs 260-263 retaining the tamper-evident panels 251 in position on the top panel 201 of the screw cap 200.

As noted above, the internal pressure of soft drink and beer containers can generate, for example, a force of about 58 pounds when the beverages are carbonated to 4.2 atmospheres and the temperature is about 100°. Preferred first means 100 of the invention can generate seal-maintaining forces of about 100-115 pounds and thus provide a 50-pound differential force maintaining the elastomeric seal- forming material 103 in engagement with the top of the container.

With the threads normally found on containers for carbonated beverages 3 degrees of rotation will lift the screw cap 200 approximately one-thousandths of an inch (0.001 inch) upwardly, which, of course, reduces the seal-maintaining force generated by the resilient portion 104 of the first means 100. In the worst case, approximately 8-12 degrees rotation of the screw cap 200 occurs before the seal-maintaining force generated by the resilient peripheral portion 104 of the first means 100 is reduced to the forces typically generated by the internal pressure of a soft drink container, for example, 58 pounds. The plurality of frangible portions or spokes 260-263 retaining the tamper-evident panel portions 251 connected with the top panel 200 must break and tear with a force of about one pound or less. To achieve such operation, top panel must be formed and scored to leave, for example, each of spokes 260-263 with a thickness of about 0.002 to 0.005 inches if the screw cap 200 is formed of polypropylene, thus providing about one- fourth pound to break each spoke or about one pound to remove each tamper-evident panel 251. With such embodiments, the tamper-evident panels are substantially removed from the top panel 201 before the seal is broken.

As shown in Fig. 7 the underside of the threaded cap 200 may be provided with alignment buses 270 so that the scoring tools can be aligned with the frangible channel portions 254-257 (Figs. 13 and 14) surrounding each tamper-evident panel 251'.

An inexpensive and preferable method of manufacturing a screw cap 200 is to injection mold the screw caps 200 including the features shown and described above, and, after removal of the screw caps 200 from the injection molding dies, to support the cap from within and score the peripheral portions 254- 257 defining the tamper-evident panels 251, and, after the scoring operation, to add adhesive to the actuating tabs 252, and thereafter insert the closure disks 100 within the screw caps 200 as described above.

The closure disks 100 may be easily manufactured by stamping the disks from coated steel or other such resilient material, into the preferred shape described above, and thereafter by compression molding or otherwise applying the elastomeric seal/friction forming material onto the periphery of the formed closure disk, and, if necessary, by applying hot melt, or a part of an adhesive, on the upper surface of the closure disk.

Fig. 20 is a perspective view of another form of closure 300 of my invention. Closure 300 includes a second means 310 that is formed with at least one and preferably a plurality of vent passages 311 between its skirt portion 302 and its outer surface 303. As shown in Fig. 20, the outer surface 303 of the screw cap 300 has a somewhat squared shape as a result of four vent passageways 311 formed outside of the skirt portion 302 and between the skirt portion 302 and the outer surface 303 of the screw cap. The four vent passageways 311 open into the exterior of screw cap 300 through one or more openings 312 at the top of each vent passageway 311. Closure 300 is otherwise identical with closure 50 and includes an identical first means or closure disk 100 described above and other than the passageway opening 312, the inner surfaces of screw cap 310 can be the same as those of screw cap 200. Thus, when the seal is broken between the closure disk 100 and the container, the vent gas travels through openings 312 and vent passageways 311 and exits the bottom of the closure 300. In closure 300, the thread formed within the skirt 302 may be continuous and need not provide a vent passage. While closure 300 is shown with four vent passageways 311 to provide an attractive and easily grasped, somewhat square outer surface 303, such closure may also be formed with an oval and elliptical outer surface 303 and two vent passageway 311, and, indeed, a single vent passageway 311 may be formed in the invention between the threaded skirt 302 portion and the outer surface 303, and in all such closures the non-round outer surface may facilitate rotation of the closure on the container.

An alternative preferred embodiment of the first means 400, as shown in Figs. 21-23, preferably comprises a closure disk manufactured from non- resilient, inexpensive metal or plastic so as to form a cup-shaped portion or plug 402. The plug 402 comprises a non-resilient central panel 404 encircled at its periphery by an upwardly extending annular collar 406, with a peripheral portion 408 extending radially outwardly from the peripheral annular collar 406. The plug 402 is sized to fit into the open mouth of the container 60 with the annular collar 406 extending concentrically within the inside surface of the mouth-forming top of the container a preferable distance of at least 0.030 inch (0.076 cm). The peripheral portion 408 extends radially outwardly sufficiently to engage the interior disk retaining tabs 221 of the screw cap 412 so as to be rotatably held within screw cap 412, as shown in Fig. 23.

A layer of elastomeric sealing material 410 is attached to the plug 402 by conventional methods and covers at least the peripheral annular collar 406 from the central panel 404 to the peripheral portion 408. The plug 402 is sized to squeeze the elastomeric sealing material 410 between the upwardly extending annular collar 406 and the interior surface 59 of the open mouth 61, as shown in Fig. 23, to provide an interfering and sealing engagement between the plug 402 and the container 60. It will be appreciated that the entire plug can be manufactured from the elastomeric sealing material 410, provided that the elastomeric sealing material 410 has sufficient stiffness to maintain an interfering seal when the plug 402 is inserted into the open mouth 61 of the container 60.

The elastomeric sealing material 410 serves a dual role. In addition to providing a seal, the sealing material 410 provides a non-rotative force that resists rotation of the plug 402 relative to the container 60 when the screw cap 412 is removed. This non-rotative force can be controlled by increasing or decreasing the interference between the plug 402 and the mouth-forming top of the container 60. For example, by increasing the height of the annular collar 406, the non-rotative force can be increased by providing a larger area of contact between the elastomeric material 410 and the interior surface 59 of the open mouth 60. It should be noted, however, that the height of annular collar 406 should not be decreased significantly below 0.030 inches (0.076 cm) because of the lifting effect that internal pressure, such as that caused by carbonated beverages, can have on control panel 404. Such internal pressures can lift an aluminum closure disk as much as 0.020 inches (0.051 cm). The non-rotative force can also be controlled by the selection of the elastomeric sealing material 410 and its thickness on annular collar 406.

While the first means 400 includes an upwardly extending annular collar 406, as shown in Figs. 21 and 23, the upwardly extending annular collar 406 may be formed by a plurality of upwardly extending annular collar portions extending uniformly and spaced about the central panel 404, provided that the elastomeric sealing material 410 between the plurality of upwardly extending annular collar portions is urged into sealing engagement with the container top through its thickness and support.

As shown in Fig. 21, the peripheral portion 408 extends upwardly at a small acute angle X with respect to the plane of central panel 404. The upward extension of peripheral portion 408 reduces the outside diameter of closure disk 400 permitting closure disk 400 to pass more freely the disk- retaining tops 221 of screw cap 412 upon assembly of the closure disk 400 and screw top 412 as described above and shown in Figs. 12A and 12B. As shown in Fig. 23, when closure disk 400 has been urged into engagement with the mouth-forming top 61 of the container, peripheral portion 408 is deformed into a plane more parallel to the plane of central panel 404, and the outside diameter of closure disk 400 is increased, for example, by as much as 0.008 inch (0.020 cm). Because of its increased diameter after application to the container 60, the interference between the outside diameter of closure disk 400 and the disk-retaining tabs of the screw cap 412 is increased and a greater lifting force can be imparted to closure disk 400 by screw cap 412 as it is removed from container 60. The greater lifting force permits increased interference between the closure disk collar 406 and mouth-forming top 61 of the container 60.

The screw cap 412 includes an alternative embodiment of the tamper-evident portions and actuating tabs. In all other respects, the second means of the alternative embodiment, which includes the screw cap 412, is substantially similar to the screw cap 200 described above with respect to Figs. 6- 11 and can be substantially similar to the screw cap 300 described above with respect to Fig. 20.

In the alternative embodiment shown in Figs. 24- 26, the screw cap 412 includes a top panel 420 having at least one tamper-evident panel portion 422. The tamper-evident panel portion 422 includes a frangible perimeter portion 424 and an actuating tab 452 extending downwardly from the tamper-evident panel portion 422 for engagement with the first means 400 when the screw cap 412 has carried the first means 400 into sealing engagement with the container 60 as shown, for example, in Fig. 23. A high friction material for frictionally engaging first means 400 and second means 412 is applied between the actuating tab 452 and the upper surface of central panel 404, preferably by applying high friction material to the upper surface of control panel 404 where it will be contacted by actuating tab 452. Such high friction material may be adhesively attached grit or abrasive or an adhesive or tacky material.

The actuating tab 452 extends downwardly from the tamper-evident panel portion 422 in the direction of rotation as a screw cap 412 is threaded onto the container and includes a first end 452a, an intermediate portion 452b and a second end 452c. The first end 452a is attached centrally to one end of the tamper-evident panel portion 422, and the intermediate portion 452b extends downwardly from the first end 452a at an acute angle to the top panel 420. The second end 452c curves upwardly from the intermediate portion 452b and extends to contact the top panel 420 at a position adjacent the other end of the tamper- evident panel portion 422, as shown in Figs. 24-25. The curved second end 452c provides resilient means to supply a downward force against the first means 400, thereby increasing the friction force between the actuating tab 452 and the first means 400 provided by the high friction material. Thus, when the screw cap 412 is rotated for removal from the container 60, the actuating tab 452 will have a tendency to stay with the non-rotative first means 400. Since the first means 400 is retained in position in the open mouth 61 of the container 60 during removal of the screw cap 412, as described above, the actuating tab 452 pulls the tamper-evident panel portion 422 out of the top panel 420.

As shown more clearly in Fig. 24, the tamper- evident panel portion 422 is defined by a segmented frangible portion 453 including segments 454-457 of reduced top panel thickness. As shown in Fig. 25, the segments of reduced thickness are, after molding of the screw cap, scored, at 455a, 456a and 457a so that the tamper-evident panel 451 is retained in the top panel 420 by only a plurality of spokes of material 460-463 to control the force required to tear the tamper-evident panel 451 from the top panel 420 of the screw cap. Thus, after the top panel 420 of the screw cap has been scored, each of the tamper-evident panels 451 are held in place by the body of the top panel 420 remaining between the scored segments in spoke-like form, shown as spokes 460-463, as shown in Fig. 25.

Fig. 26 illustrates the tamper-evident panel 451 torn from its position in the top panel 420 by breaking of the spoke portions 460-463 and tearing along the scored segments 455a, 456a and 457a. The tamper-evident panel 451, actuating tab 452, scored segments 454a, 455a, 456a, 457a, and spoke portions 460-463 interact to fold the tamper-evident panel 451 as shown in Fig. 26. As the top panel 420 is rotated by a user, actuating tab 452, which is stationary, imposes a force directed along the acute angle of its intermediate portion 452b on the one end 451a of the tamper-evident panel 451 to which it is attached. Because of the reinforcing effect of the first end 452a of the actuating tab 452 on the end 451a of the tamper-evident panel to which it is attached, end 451a of the tamper-evident panel 452 is inherently more rigid than the other end 452b of the tamper-evident panel 452. As a result, end 451a imposes the force from actuating tab 452 on scored segments 455a, 456a and 457a and on spoke portions 460-463, which break and permit relative movement between top panel 420 and the other end 452b, which remain attached to top panel 420 and end 451a and with the continuing movement of screw cap 412 and its top panel 420 in the direction 475 shown in Fig. 26, end 452b is progressively torn from top panel 420 and folded under the more rigid end 451a until it is finally separated from the top panel. To assist in the folding, the tamper-evident panel 451 may be provided with different thicknesses in its ends 451a and 451b. The spoke portions 460-463, and the scored segments 454a-457a can also be designed to allow the tamper-evident panel 451 to tear in a controlled manner. Segment 454 is more difficult to tear away because it is on the leading edge during removal, and it interferes with itself across the scored area, and thereby bends the tamper-evident panel 451 back onto itself so that the end 452b lies substantially parallel to the first portion to tear away, as shown in Fig. 26. Once torn, the rigidity of the material of the tamper-evident panel 451 maintains the panel 451 in the bent configuration. Advantageously, even if the tamper-evident panel 451 should align itself with one of the apertures 459 when the closure is reapplied to a container 60, the tamper evidence will be retained because of the folded configuration of the panel 451.

In Fig. 26 the top panel 420 of the screw cap 412 has been counter-rotated in the direction drawn by arrow 475 and the first means 400 (shown only partially in Fig. 26 for clarity) has remained stationary on the container as described above. Because of the frictional engagement of the actuating tab 452 and the first means 400, the actuating tab 452, through the frictional force caused by the high friction material, has torn the tamper-evident panel 451 from the top panel 420 to provide tamper evidence as shown in Fig. IB.

Capping heads in use in the bottling industry have a flat rigid surface that bears down on the entire top surface of a cap as it is screwed onto the bottle finish. The closure of the invention uses the engagement of the top panel 420, and its tamper- evident portion or portions 451, with the flat rigid surface of the capping head to prevent the tamper- evident panels 451 from being torn or dislodged from the top panel 420. As the screw cap 412 is placed on the container, any relative motion between the top panel 420 and actuating tabs 452 and the fasteners or closure disk 400 in the opposite direction to that shown as 475 in Fig. 26, and any force imposed on the tamper-evident panels 451 by the actuating tabs 452 will be in a direction upwardly, rather than downwardly as illustrated in Fig. 26. The downward force applied to the tamper-evident portions 451 of the screw cap 412 by the capping head will prevent movement of the tamper-evident portion 451 upwardly out of position during capping. To provide further clear evidence of the tampering with the container, the top surface of the first means 400 may be coated with a bright color which contrasts with a white color for the molded screw cap 400.

Although the invention has been described in detail with reference to a certain preferred embodiment, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.

Claims

1. A closure for the mouth-forming top of a threaded container, comprising a screw cap including a top panel and a skirt with thread means for engaging the threaded top of the container, said top panel spanning the mouth- forming top of the container, and including at least one tamper-evident panel portion defined by a frangible portion of the top panel and an actuating tab extending from said tamper-evident panel portion; and a closure disk being sized to close the mouth-forming top of the pressurized container at its periphery and carried by the screw cap under and adjacent the top panel with its upper surface adapted to engage the actuating tab, said closure disk comprising an elastomeric seal carried at its periphery and a peripheral portion extending radially outwardly from said periphery into engagement with said screw cap, wherein upon the advancement of the thread means of the screw cap on the threaded top of the container, the closure disk is carried downwardly onto the mouth-forming top of the bottle, the elastomeric seal is compressed between said closure disk and the mouth-forming top of the container to form a seal and the peripheral portion engages the mouth-forming top of the container, said closure disk providing a force resisting relative rotation between the closure disk and container when seated on said container top, and wherein upon initial rotation of the screw cap in its removal from the container, the force immovably retains the closure disk and the resulting relative rotation of the screw cap with respect to the closure disk breaks the frangible portion of the top panel and actuates the at least one tamper-evident panel portion of the top panel through the engagement of the actuating tab with the top surface of the closure disk.

2. The closure of claim 1 wherein the closure disk forms a plug that is configured to carry the elastomeric seal into engagement with the interior of the top of the container.

3. The closure of claim 1 wherein the screw cap includes one or more interior surfaces adjacent the underside of the top panel for engagement by and location of the closure disk and its upper surface from the top panel of the screw cap.

4. The closure of claim 1 wherein the actuating tab extends downwardly from the tamper-evident panel portion and terminates in an engagement surface disposed to contact a portion of the upper surface of the closure disk.

5. The closure of claim 4 wherein a friction material is located between the upper surface of said closure disk and the engagement surface of the actuating tab to resist relative movement between the actuating tab and the closure disk when the screw cap is removed from the container.

6. The closure of claim 5 wherein the actuating tab includes a curved portion extending upwardly from the engagement surface between the actuating tab and the closure disk to contact the screw cap at a point adjacent the at least one tamper-evident panel portion.

7. The closure of claim 1 wherein the actuating tab includes a first end attached to the tamper- evident panel portion and an intermediate portion extending downwardly from the first end at an acute angle to the at least one tamper-evident panel portion.

8. The closure of claim 7 wherein the actuating tab includes resilient means for urging the actuating tab into contact with the closure disk.

9. The closure of claim 8 wherein the resilient means includes a curved second end connected to the intermediate portion, the second end curving upwardly from the intermediate portion and sized to be compressed between the closure disk and the top panel when the screw cap is advanced onto the threaded top, the second end contacting the top panel adjacent the at least one tamper-evident panel portion.

10. The closure of claim 7 comprising means for resisting relative movement between the actuating tab and the upper surface of the closure disk to assist breaking the frangible portion of the top panel and actuating the at least one tamper-evident panel portion of the top panel in response to unthreading of the screw cap from the threaded top of the container.

11. The closure of claim 1 wherein said frangible portion of the screw cap comprises a scored channel extending at least partially around the at least one tamper-evident portion.

12. The closure of claim 11 wherein said frangible portion further comprises a plurality of frangible spoke-like portions extending across the scored channel between the top panel and the at least one tamper-evident panel portion, the spoke-like portions having a controlled cross-sectional area to provide a controllable breaking force for the tamper- evident panel portion.

13. The closure of claim 1 wherein the actuation of the at least one tamper-evident panel portion results in controlled removal of the at least one tamper-evident panel portion so that at least a part of the tamper-evident panel portion is bent back to lie in parallel relation to the remainder of the tamper-evident panel portion.

14. The closure of claim 1 wherein said frangible portion of the screw cap comprises a scored channel extending at least partially around the at least one tamper-evident portion and forming a plurality of frangible spoke-like portions extending across the scored channel between the top panel and the tamper-evident panel portion, the spoke-like portions having a controlled cross-sectional area to provide a controllable breaking force for the tamper- evident panel portion so that the actuation of the at least one tamper-evident panel portion results in controlled removal of the tamper-evident portion.

15. The closure of claim 1 wherein the closure disk includes a compression rib for engaging the mouth-forming top of the container and limiting compression of the seal.

16. The closure of claim 1 wherein the peripheral portion is resilient and is attached to a compression rib and wherein the resilient peripheral portion is deformed by engagement with said screw cap upon advancement of the thread means of the screw cap on the threaded top of the container to generate said force resisting relative rotation between the closure disk and container.

17. The closure of claim 1 wherein a plurality of disk retention tabs are located within the skirt of the screw cap to engage the peripheral portion of the screw cap and carry the closure disk within the screw cap, and wherein the peripheral portion extends radially outwardly at an acute angle with respect to said closure disk and is deformed upon advancement of the thread means of the screw cap onto the threaded top of the bottle to increase the outside diameter of the closure disk and the engagement of closure disk with the plurality of tabs.

18. The closure disk of claim 1 wherein the skirt portion of the screw cap is deformable and resilient and carries a plurality of disk retention tabs for retaining the closure disk in the screw cap; and the skirt portion, upon the application of deforming forces, permits the closure disk to be inserted past the disk retention tabs and, upon release of the deforming forces, returns to substantially its original shape where the disk retention tabs engage and retain the closure disk within the screw cap and adjacent the top panel.

19. The closure disk of claim 1 wherein the actuating tab extends from the at least one tamper- evident panel portion in the direction of rotation as the screw cap is threaded onto the container.

20. The closure disk of claim 11 wherein the underside of the top panel of the screw cap includes at least one projecting surface for location of the screw cap for scoring the top panel form above.

21. The closure of claim 15 wherein the closure disk and compression rib are formed to provide one or more channels allowing a flow of material of the elastomeric seat to adjacent the resilient peripheral portion of the closure disk.

22. A method of initially sealing a container such that a tamper-evident feature is readied for actuation, said container having an externally threaded, hollow neck finish which terminates in a circular top lip, said method comprising the following steps: providing a disk and an elastic seal combination which is suitably sized to cover said circular top lip; providing a cap having a frangibly attached tamper-evident panel portion and an internally threaded shell having retainers therein, which are suitable for snap-fit engagement with, and rotatable carriage of, said disk and elastic seal combination; pushing said disk and elastic seal combination upwardly into said shell, until said disk and elastic seal combination snaps into engagement in said shell; establishing threaded engagement between said shell and said neck finish; advancing said shell onto said neck finish so as to press said disk and elastic seal combination into sealing contact with said hollow neck and said disk into operable engagement with said frangibly attached tamper-evident panel.

23. The method of claim 22 wherein said disk and elastic seal combination forms a plug that is configured to extend into and engage the hollow neck of the container and provide a force to initially retain said disk and elastic seal combination immovable and detach said tamper-evident panel during removal of said cap from the container.

24. The method of claim 22 wherein said disk comprises a resilient peripheral portion and advancement of shell onto said neck finish deforms said resilient peripheral portion of said disk and provides a force to initially retain said disk and elastic seal combination immovable and detach said tamper-evident panel during removal of said cap from said container.

25. An open mouthed container closure, comprising first means for forming a seal of the open mouth of the container and for generating a rotation- resisting force; and second means for carrying said first means into closing and sealing engagement with the container adjacent its open mouth by rotation of said second means with respect to said container, and for providing tamper-evidence when said second means has been counter-rotated on said container, said first means, through its rotation- resisting engagement with the open mouth of the container, remaining fixed during the first counter- rotation of said second means and thereby, through an engagement with said second means, operating the tamper-evident portion of said second means as a result of relative rotation between said first means and said second means.

26. The closure of claim 25 wherein the first means includes a cup-shaped portion and a peripheral portion extending radially outwardly from the cup- shaped portion, the cup-shaped portion further including an elastic sealing material.

27. The closure of claim 26 wherein the elastic sealing material is disposed for engagement with the open top of the container and the peripheral portion is disposed for deformable engagement between said second means and the container adjacent its open top.

28. The closure of claim 27 wherein the peripheral portion of the first means is resilient and is deformed by said second means so the resilience of the peripheral portion generates said rotation resisting force.

29. The closure of claim 27 wherein the deformable engagement of said peripheral portion of said first means increases the outside diameter of said first means.

30. The method of claim 27 wherein an interference between said elastic sealing material and the inside of the open top provides said rotation resisting force.

31. The closure of claim 25 wherein said second means includes a tamper-evident panel portion and an actuating tab extending from said tamper-evident panel portion.

32. The closure of claim 31 wherein the actuating tab includes a first end attached to the tamper-evident panel portion, an intermediate portion extending downwardly from the first end at an acute angle to the tamper-evident panel portion and a second end extending from the intermediate portion and contacting the first means.

33. The closure of claim 32 wherein a material for providing a force for resisting relative movement between the actuating tab and the first means is provided between said actuating tab and the first means.

34. The closure of claim 33 wherein the second end includes a curved portion, the curved portion contacting the first means and curving upwardly from the point of contact with the first means to contact the second means at a position adjacent the tamper- evident panel portion when said second means has carried said first means into sealing engagement with said container, the curved portion being adapted to provide a downforce to increase the force between the actuating tab and the first means.

35. The closure of claim 33 wherein a friction material provides a friction retaining force between said first means and the actuating tab to resist relative movement between the actuating tab and the first means.

36. The closure of claim 31 wherein the tamper- evident panel portion is adapted to tear out of the second means in response to relative rotation between the first means and the second means so that a part of the tamper-evident panel portion bends back to lie in parallel relation to the remainder of the panel portion.

37. The closure of claim 28 wherein said first means and said second means each include load-bearing portions, said load bearing portions being moved into engagement with each other and with the container to thereby in combination, transfer stacking loads imposed on said second means to said container without affecting the sealing engagement of said first means with the open mouth of the container.

38. The closure of claim 25 wherein said first means includes a portion of its periphery adapted to preferentially release its sealing engagement with the open-mouth of the container as said second means is counter-rotated.

39. The closure of claim 25 wherein said second means includes at least one internal surface to engage and locate said first means within said second means.

40. The closure of claim 28 wherein the first means includes a plug sized and shaped to fit inside the open mouth of the container.