US20050092750A1

US20050092750A1 - Method of joining separable components and container closure system formed by the same

Info

Publication number: US20050092750A1
Application number: US10/854,925
Authority: US
Inventors: Richard Lohrman; Brian Adams
Original assignee: Individual
Current assignee: Portola Packaging Inc
Priority date: 2003-05-27
Filing date: 2004-05-26
Publication date: 2005-05-05
Also published as: WO2004106172A2; US20110100948A1; US7832579B2; NZ568141A; EP1636103A2; ZA200509843B; WO2004106172A3; CN1816480A; US20070095835A1; US20080179276A1; NZ543862A; US20080272084A1; AU2004243320B2; CN1816480B; US20110011821A1; CA2527007C; MXPA05012719A; CA2527007A1; AU2004243320A1

Abstract

A tamper-evidencing closure for a container including a first component having a first interlocking structure and a second, plastics injection molded component having a second interlocking structure molded in situ against the first interlocking structure. The second interlocking structure is complementary in shape to the first interlocking structure and is in mechanical interlocking engagement with the first interlocking structure. The mechanical interlocking engagement is releasable without fracture of at least one of the first and second interlocking structures. A method of using the tamper-evidencing closure is also disclosed.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 60/473,847 filed May 27, 2003, entitled METHOD OF JOINING SEPARABLE COMPONENTS AND CONTAINER CLOSURE SYSTEM FORMED BY THE SAME, the entire contents of which is incorporated herein by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates, in general, to a method of joining separable components and to container closure systems formed by the same, and more particularly to tamper-evidencing closure systems and methods for their use.
2. Description of Related Art
Tamper-evidencing closure systems are known and often include a closure having a removable tamper-evidencing portion that is monolithically formed with the remainder of the closure. Opening of such known closures generally involves fracturing the closure and tearing the tamper-evidencing portion from the remainder of the closure upon initial opening of the container.
One known type of closure system utilizes a cap having a skirt and a tamper-evident band dependent from and monolithically joined to a base of the skirt. The band is engaged with complimentary structure on a corresponding container and is severed from the cap skirt when the closure is initially removed. The severing is allowed by making the interconnection between the tamper-evident band and the cap skirt frangible and easily broken. Typically, discrete breakable “bridges” or a continuous thin “score line” is utilized to form the frangible connection.
One exemplar of the prior art is U.S. Pat. No. 5,480,045 to Molinaro et al. which discloses a cap including a frangible tear skirt 25 interconnected with a depending wall 22 by frangible connection members 27. Another exemplar of the prior art is U.S. Pat. No. 5,284,265 to Crisci which discloses a cap having a frangible tear skirt 14 interconnected with cap top 13 along a score line, that is, tear line 16.
Another known closure system involves monolithically molded pull-out membranes, as commonly employed on gable-top juice containers and some vegetable oil containers. This system incorporates a removable membrane initially closing a dispensing orifice of the container. The membrane is monolithically formed with additional structure appropriate for attachment to the container such as a weld flange or a snap attachment skirt. The membrane is integrally connected to the attachment structure through a frangible line of weakness. Upon initial opening by a consumer, a finger tab joined to the membrane is gripped and pulled by the consumer, thereby removing the membrane by fracturing the closure and tearing the membrane away from the additional structure along the frangible line of weakness.
An exemplar of the prior art is U.S. Pat. No. 5,810,184 to Adams et al. which discloses a fitment having a removable membrane 32 interconnected with a spout along a line of weakness or tear line 36.
While prior closure systems function quite successfully, current systems using frangible separation of integrally molded components have several disadvantages. In the case of dependent breakaway tamper-evidencing bands, the demands of application and retention of the tamper-evidencing band often conflict with the requirements of the primary closure portion. For example, when discrete bridges are employed, the mechanical characteristics required for bridge integrity during application often conflict with the mechanical characteristics appropriate for easy removal by a consumer upon opening the closure system. In the case of continuous frangible score lines or tear lines, material selection is normally restricted to forms of low density polyethylene, since this is the only commodity material exhibiting facile tear performance.
Similarly, pull-out membrane closure systems generally include a membrane, a frangible score line, and an attachment structure which are monolithically molded in a single integral shot during an injection molding operation. Such configuration significantly restricts possible material choices for forming the system. The frangible score line must easily and readily tear without excessive force. As noted above, the most applicable material in this regard is low density polyethylene, however, specifying that the frangible line be made of low density polyethylene further specifies that the membrane itself, and more importantly the attachment structure, be formed of the same low density polyethylene material. Disadvantageously, this can negatively impact potential applications, since the mechanical properties of low density polyethylene may not be appropriate to accomplish the performance required for package integrity.
A further problem intrinsic with pull out membrane technology is that substantial material flow is required across a thin frangible score line which connects the pull out membrane to the container attachment structure. This configuration may lead to unusual and unpredictable performance including, but not limited to, microscopic pin holes, lamination and difficult tearing resulting from physical properties of the material which may change as the material traverses the thin frangible scoreline.
What is needed is a new and improved tamper-evidencing closure system which overcomes the above and other disadvantages of known closure systems.

BRIEF SUMMARY OF THE INVENTION

In summary, one aspect of the present invention is directed to a method of joining separable components including: providing a first component having first interlocking structure; and molding a second component in a plastics injection molding process within a mold utilizing a surface of the first interlocking structure of the first component as a portion of the mold, the second component being formed with second interlocking structure complementary to the first interlocking structure which mechanically interlocks the first component and the second component, the mechanical interlock being releasable without fracture of at least one of the first and second interlocking structures.
In one embodiment, the molding step further forms the mechanical interlock to be releasable without fracture of the first and second interlocking structures. The molding step may form the first and second interlocking structures such that the interlocking structures cannot be reassembled after the mechanical interlock has been released. In one embodiment, the providing step is accomplished by providing the first interlocking structure with a recess having first trapezoidal cross-section and the forming step is accomplished by forming the second interlocking structure with a protrusion having a second trapezoidal cross-section complementary to the first trapezoidal cross-section.
Another aspect of the present invention is directed to a closure for a container including a first component having a first interlocking structure and a second, plastics injection molded component having a second interlocking structure molded in situ against the first interlocking structure. The second interlocking structure is complementary in shape to the first interlocking structure and is in mechanical interlocking engagement with the first interlocking structure. The mechanical interlocking engagement is releasable without fracture of at least one of the first and second interlocking structures.
In one embodiment, the mechanical interlocking engagement is releasable without fracture of the first and second interlocking structures. Preferably, the first and second interlocking structures cannot be reassembled after the mechanical interlocking engagement has been released.
Yet another aspect of the present invention is directed to a tamper-evidencing closure for a container having a container opening in which the closure includes a closure base having a dispensing aperture adapted for mounting on the container adjacent the container opening, a sealing member for closing the dispensing aperture and the container opening, and a connection member releasably interconnecting the closure base and the sealing member. One of the closure base and the sealing member is formed of a first material and the connection member is formed of a second material, the second material being more pliable than the first material.
In one embodiment, the closure base further includes an annular top, a well defined by an inner skirt depending downwardly from an inner perimeter of the annular top, and an annular bottom extending radially inward from the inner skirt, the bottom having a closure aperture for accessing the container opening, and the first interlocking structure including a recess located on the annular bottom. The recess may be an outwardly-extending trapezoidally-shaped recess. The closure base may include a retainer for securing the closure base to the container. The closure base may include an outer skirt depending downwardly from an outer periphery of the annular top, the retainer including a retaining band extending inwardly and upwardly from a lower portion of the outer skirt.
In one embodiment, the sealing member includes a pull-ring. One of the sealing member and the connection member may include a peripheral lip and the other one of the sealing member and the connection member may include a continuous ring having an engagement groove cooperating with the peripheral lip to mechanically interlock the connection member and the sealing member.
Either the closure base and/or the connection member may include a recess and the other of the closure base and/or the connection member may include a protrusion complementary in shape to the recess. The protrusion and/or the recess may have trapezoidally-shaped cross-sectional profiles.
The closure base may be formed of polypropylene, high-density polyethylene, and/or low-density polyethylene. The sealing member may be formed of polypropylene, high-density polyethylene, and/or low-density polyethylene. The connection member may be formed of low-density polyethylene and/or thermoplastic elastomer.
In one embodiment, the closure may be dimensioned and configured for use with a container having a container opening, a neck finish, and a locking surface on the neck finish. The closure may further include a plurality of retaining flaps extending radially inwardly and upwardly from a lower portion of an outer skirt of the closure base, each the retaining flap including an oblique wing having a arcuate inner edge adapted to engage the locking surface of the container, wherein each wing includes a concave lower surface dimensioned and configured to closely approximate the outer diameter of the neck finish below the locking surface allowing substantially the entire the inner edge to contact the locking surface. The neck finish may include an anti-rotation structure, and the closure may further include a vertically extending gusset extending along at least one of the flaps and being dimensioned and configured to abut against the anti-rotation structure of the neck finish. The closure may further include a plurality of biasing ribs extending radially inward from an inner surface of the outer skirt toward a respective one of the flaps to bias the inner edges into contact with the locking surface of the container.
In one embodiment, the closure may further include a plurality of lines of weakness extending upwardly along a lower portion of an outer skirt of the closure base, the lines of weakness being dimensioned and configured to split upon at least partial removal of the closure from the container. The lines of weakness may extend substantially vertically along the lower portion of the outer skirt.
Another aspect of the present invention is directed to a tamper-evidencing closure for a container having a container opening, a neck finish, and a locking surface on the neck finish. The closure includes a closure base having a top and an annular outer skirt depending from a periphery of the top, a plurality of retaining flaps extending radially inwardly and upwardly from a lower portion of the outer skirt, each the retaining flap including an oblique wing having a arcuate inner edge adapted to engage the locking surface of the container, wherein each wing includes a concave lower surface dimensioned and configured to closely approximate the outer diameter of the neck finish below the locking surface allowing a majority of the inner edge to contact the locking surface.
The neck finish may include anti-rotation structure and the closure may further include a vertically extending gusset extending along at least one of the flaps and being dimensioned and configured to abut against the anti-rotation structure of the neck finish. The closure may further include a plurality of biasing ribs extending radially inward from an inner surface of the outer skirt toward a respective one of the flaps to bias the inner edges into contact with the locking surface of the container when the closure is mounted on the container. The closure may further include a plurality of circumferentially spaced lines of weakness extending substantially vertically along the lower portion of the outer skirt, the lines of weakness being dimensioned and configured to split upon partial removal of the closure from the container.
Yet another aspect of the present invention is directed to a tamper-evidencing closure for a container having a container opening, a neck finish, and a locking surface on the neck finish. The closure includes a closure base having a top and an annular outer skirt depending from a periphery of the top, a retainer extending radially inwardly and upwardly from a lower portion of the outer skirt, and a plurality of circumferentially spaced lines of weakness extending biasing ribs extending upwardly along the lower portion of the outer skirt, the lines of weakness being dimensioned and configured to split upon partial removal of the closure from the container.
In one embodiment, the plurality of lines of weakness extend substantially vertically along the lower portion of the outer skirt. The plurality of lines of weakness may extend substantially parallel to one another. The plurality of lines of weakness may extend from a bottom edge of the lower portion of the outer skirt.
An object of the present invention is to provide a tamper-evidencing closure system having interconnected discrete components that can be separated in a facile manner by a consumer to yield individual components that cannot be reassembled.
Another object of the present invention is to provide a method of forming the above-mentioned tamper-evidencing closure system.
Another object of the present invention is to provide a closure base that securely engages a locking surface of a container neck finish.
Yet another object of the present invention is to provide means to resist rotation between a closure base and a container neck finish.
A further object of the present invention is to provide tamper evidencing means extending along a lower skirt portion of a closure.
The tamper-evidencing closure system of the present invention has other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain the principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tamper-evidencing closure system in accordance with the present invention.
FIG. 2 is a top plan view of the closure system of FIG. 1.
FIG. 3 is a side elevational view of the closure system of FIG. 1.
FIG. 4 is a cross-sectional view of the closure system of FIG. 1 taken substantially along line 4-4 of FIG. 2.
FIG. 5 is a cross-sectional view of the closure system of FIG. 1 taken substantially along the line 5-5 of FIG. 2.
FIG. 6 is a cross-sectional view of the closure system of FIG. 1 taken substantially along the line 6-6 of FIG. 2.
FIG. 7 is a perspective view of another tamper-evidencing closure system in accordance with the present invention.
FIG. 8 is a bottom perspective view of the closure system of FIG. 7.
FIG. 9 is a top plane view of the closure system of FIG. 7 showing a closure base having a reclosure cap mounted thereon.
FIG. 10 is a cross-sectional view of the closure system of FIG. 7 taken substantially along the line 10-10 of FIG. 9.
FIG. 11 is an enlarged detail of FIG. 10.
FIG. 12 is a cross-sectional view of the closure system of FIG. 7 taken substantially along the line 11-11 of FIG. 9.
FIG. 13 is an enlarged detail of FIG. 12.
FIG. 14 is a perspective view, similar to FIG. 7, of another tamper-evidencing closure system in accordance with the present invention.
FIG. 15 is a bottom perspective view of the closure system of FIG. 14.
FIG. 16 is a cross-sectional view, similar to FIG. 4, of another tamper-evidencing evidencing closure system in accordance with the present invention.
FIG. 17 is an upper perspective view of another tamper-evidencing closure system in accordance with the present invention.
FIG. 18 is a lower perspective view of the closure system of FIG. 17.
FIG. 19 is a cross-sectional view of the closure system of FIG. 17.
FIG. 20 is an upper perspective view of a neck finish of a container that may by used in combination with one or more of the above closure systems.
FIG. 21 is a side elevational view of the neck finish of FIG. 20.
FIG. 22 is a cross-sectional, fragmentary plan view of the neck finish of FIG. 20, taken substantially along line 22-22 of FIG. 21.
FIG. 23 is a cross-sectional, fragmentary side elevational view of the neck finish of FIG. 20, taken substantially along line 23-23 of FIG. 22.
FIG. 24 is a partial cross-sectional, side elevational view of the closure system of FIG. 17 applied to the neck finish of FIG. 20.
FIG. 25 is a cross-sectional, fragmentary plan view of the closure system of FIG. 17 applied to the neck finish of FIG. 20, taken substantially along line 25-25 of FIG. 24.
FIG. 26 is an upper perspective view of another closure system in accordance with the present invention.
FIG. 27 is an upper perspective view of a connection member of the closure system of FIG. 26.
FIG. 28 is a plan view of the closure system of FIG. 26.
FIG. 29 is an enlarged cross-sectional view of the closure system of FIG. 26 taken along line 29-29 of FIG. 28.
FIG. 30 is an enlarged cross-sectional view of the closure system of FIG. 26 taken along line 30-30 of FIG. 28.
FIG. 31 is an upper perspective view of another closure system in accordance with the present invention.
FIG. 32 is a lower perspective view of the closure system of FIG. 31.
FIG. 33 is a fragmentary cross-sectional view of the closure system of FIG. 31 taken substantially along line 33-33 in FIG. 31.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.
Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to FIGS. 1-6 which illustrate a tamper-evidencing closure system, generally designated 30, which is adapted to be secured to a container (e.g., container 31 a shown in FIG. 10).
As shown in FIG. 1, closure system 30 includes a closure base 34 that is adapted for mounting on the container, a sealing member 35 for sealing the opening and thus the contents of the container, and a connection member 36 for releasably connecting the sealing member 35 to the closure base 34.
The closure base is generally dimensioned and configured to be secured to a container adjacent the opening thereof. In the embodiment illustrated in FIGS. 1-6, closure base 34 is configured to mate with a container of the type having a non-threaded neck finish of the snap-on variety (see, e.g., FIG. 23). One should appreciate, however, that the closure base of the present invention is equally suited for use with other types of containers including, but not limited to, containers having threaded neck finishes as well as paperboard containers.
With reference to FIG. 4, closure base 34 includes an annular top 39 and an outer skirt 40 depending downwardly from an outer periphery of annular top 39. An upper portion of outer skirt includes external cap-engaging threads 43 configured and dimensioned to releasably engage internal threads (e.g., cap threads 44 a as shown in FIG. 10) of a reclosure cap (e.g., cap 45 shown in FIG. 10). One should appreciate that other means can be utilized to releasably secure the reclosure cap to the closure base in accordance with the present invention. Alternatively, one should appreciate that the tamper-evidencing closure system of the present invention need not incorporate a removable cap. For example, a resealable or reclosure cap would not be necessary if the closure system of the present invention is to be used with a school milk container or other type of single serving container.
With reference to FIG. 4, a lower portion 48 of skirt 40 includes retaining structure or a retainer 49 which securely engages closure base 34 on the container. In one embodiment, retainer 49 includes a retaining band 50 that extends radially inwardly and upwardly from lower portion 48 of skirt 40 and is configured to mate with the finish of the container. In the illustrated embodiment, lower portion 48 and retaining band 50 form a J-shaped structure that is dimensioned and configured to cooperate with a locking surface (e.g., locking surface 52 a shown in FIG. 10) on the container in a manner similar to that disclosed by U.S. Pat. No. 5,913,437 to Ma, the entire content of which is incorporated herein by this reference. Unlike the structure disclosed by the '437 patent, however, the retaining band 50 is configured to provide the primary engagement between closure base 34 and the container. The J-shaped configuration facilitates application of closure base 34 to a container neck in that such configuration requires lower axial application force than other conventional closures. Advantageously, this configuration also allows greater interference between the closure plug seal and the container, which in turn provides better sealing performance.
With continued reference to FIG. 4, retaining band 50 includes a plurality of gussets 51 which are configured and dimensioned to cooperate with corresponding structure on the container neck in order to restrict rotational movement of closure base 34 with respect to container neck. In this manner, the configuration of gussets 51 facilitates threading and unthreading the reclosure cap on closure base 34 because the gussets limit rotational movement between the closure base and the container.
As illustrated in FIGS. 3 and 4, retainer 49 includes a plurality of vertical lines of weakness 53 aligned with a corresponding number of drainage holes 53 located in retainer 49 adjacent the intersection of retaining band 50 and lower portion 48 of the outer skirt. The configuration of the drainage holes 54 and vertical lines of weakness 53 provides an additional tamper-evidencing feature that facilitates damage to or destruction of closure base 34 in the event that someone attempt to remove it from the container once the closure base has been applied to the container. In particular, should someone attempt to pry closure base 34 from the container neck, lower portion 48 of the outer skirt will split along one or more vertical lines 53 thus providing visible evidence that the contents of the container may have been accessed and/or tampered with. One should appreciate that the closure base need not be provided with such vertical lines of weakness and/or drainage holes 54. In the event that the closure base includes both vertical lines of weakness and drainage holes, one should appreciate that the vertical lines need not be aligned with the drainage holes in the retaining band to provide tamper-evidencing.
Turning to FIG. 4, closure base 34 also includes an inner skirt 56 depending from an inner edge of annular top 39 and cooperates by way of an interference fit with the inside bore of the container neck (e.g., container neck 57 a shown in FIG. 11) to define a plug seal which serves as the primary seal between the tamper-evidencing closure and the container. An annular bottom 58 extends radially inward from the bottom of inner skirt 56. Inner edge 61 of bottom 58 defines an aperture that is initially closed or sealed by sealing member 35 and connection member 36. As discussed in greater detail below, a consumer may remove the sealing member and the connection member in order to gain access to the contents of the container.
The plug seal configuration of the present invention provides improved sealing performance as inner skirt 56 is supported at the top and bottom thereof. In particular, the structural integrity of the top of inner skirt 56 is reinforced by annular top 39 while the structural integrity of the bottom is reinforced by annular bottom 58.
Although the amount of application force required to apply the plug seal configuration of the present invention may be greater than a standard hollow plug, such increased application force is possible because the retainer configuration of the present invention requires a lesser amount of application force. Keeping the overall application force necessary to apply a closure to a container constant, more force can be applied to the plug seal configuration of closure system 30 because the configuration of retainer 49 requires less force, as is noted above.
Although the sealing member and connection member of the illustrated embodiment are set within a well, one should appreciate that the closure base of the present invention need not be provided with a well. For example, the connection member may directly interconnect the sealing member to the annular top in accordance with the present invention. In this example, the primary seal may be located between the annular top and the container neck. Alternatively, one should also appreciate that connection member may directly interconnect the sealing member and the outer skirt and/or other portion of the closure base. For the purpose of the present invention, the term “closure base” broadly refers to the component used to secure the tamper-evidencing closure system to a corresponding container.
Preferably, closure base 34 is formed of polypropylene, high-density polyethylene (HDPE), low density polyethylene (LDPE), or other suitable material which provides the closure base with suitable structural integrity. One should appreciate that other materials can be used in accordance with the present invention.
As most clearly shown in FIG. 1, closure system 30 also includes a sealing member 35 which is dimensioned and configured to substantially seal the aperture formed by inner edge 61 of the closure base and thus seal the container. Sealing member 35 generally includes a relatively thin membrane 62 and a gripping member 63. Membrane 62 has an outer diameter that is slightly less than the inner diameter of the aperture formed by inner edge 61. For the purpose of the present invention, the term “membrane” is also intended to cover any relatively inflexible structure that is dimensioned to substantially cover the aperture formed by inner edge 61.
Sealing member 35 also includes a peripheral lip 67 extending along the outer perimeter of membrane 62, as shown in FIG. 4. Peripheral lip 67 includes an engagement groove 70, which is configured to cooperate with connection member 36 as is discussed in greater detail below.
In the embodiment illustrated in FIG. 4, gripping member 63 in the form of a pull-ring 71 and is of generally conventional design. Namely, pull-ring 71 is connected to membrane 62 by post 72 and forms a generally circular loop. The loop is dimensioned to receive the finger of a consumer thus allowing the consumer to grip and pull the pull-ring in order to remove sealing member 35 from closure base 34.
Preferably, sealing member 35 is formed of polypropylene, high-density polyethylene (HDPE), low-density polyethylene (LDPE), or other suitable material that provides the sealing member with suitable structural integrity. One should appreciate that other materials can be used in accordance with the present invention. Preferably, the sealing member is monolithically formed with the closure base.
Connection member 36 interconnects the closure base 34 and sealing member 35. The connection member includes a continuous ring 74 that has an engagement groove 75 which cooperates with engagement groove 70 of sealing member 35 to provide a strong mechanical joint between the sealing member and the connection member, as shown in FIG. 4.
As shown in FIG. 2, connection member 36 also includes a plurality of radially extending protrusions 76 that extend outwardly from continuous ring 74. In the illustrated embodiment, twelve protrusions are circumferentially spaced about continuous ring 74. One should appreciate, however, the number of protrusions as well as spacing of the protrusions may vary in accordance with the present invention. Alternatively, a complementary groove and shoulder arrangement similar to that between sealing member 35 and connection member 36 may be used to interconnect connection member 36 as closure base 34. Likewise, a radially extending protrusion/recess configuration may be utilized to interconnect sealing member 35 and connection member 36.
As shown in FIG. 5, each protrusion 76 has a trapezoidal cross-section that is complementary to the shape of a corresponding recess 79 formed on annular bottom 58. In essence, protrusion 76 forms a key that is received within the keyway that is formed by recess 79 and thus provides a strong mechanical joint which prevents sealing member 35 from moving axially with respect to annular bottom 58 of closure base 34. One should appreciate that the cross-sectional profile of the protrusions and recesses may vary in accordance with present invention. For example, the protrusions may include a semicircular cross-section, a triangular cross-section, or other suitable profile to provide an intimate mechanical connection between the connection member and the closure base. Such cross-sectional configurations allow ready release of the interengaging structures but renders reassembly extremely difficult.
Preferably, connection member 36 is formed of a tearable material such as a low-density polyethylene (LDPE) based material or a thermoplastic elastomer (TPE). One should appreciate that other suitable tearable materials can be used in accordance with the present invention.
Connection member 36 is formed of a material that is more pliable, that is, supple enough to bend freely or repeatedly without breaking, and that would more readily yield than the material forming at least one of the sealing member and the closure base. For example, closures used in hot-fill applications are often formed of polypropylene, a relatively rigid material that possesses significant structural integrity. Disadvantageously, polypropylene is unsuitable for forming structures having a continuous tear line that is intended to be torn by a consumer. In accordance with the present invention, the closure base and/or the sealing member may be formed of polypropylene while the connection member may be formed of a low-density polyethylene (LDPE) or a thermoplastic elastomer. This two material configuration allows the use of a pull-ring in a hot-fill application.
Connection member 36 connects and joins membrane 62 of sealing member 35 to annular ring 58 of closure base 34 in such a way that the connection member does not integrally bond to at least one of the sealing member and the closure base, namely, the component is formed of the different material. In the illustrated embodiment, connection member 36 is discrete from closure base 34 and sealing member 35. However, it is understood that connection member may be integrally molded of the same material and at the same time as either one of the closure base or the sealing member provided that a mechanical joint is formed that can be readily separated by a consumer.
In one embodiment, the tamper-evidencing closure of the present invention is manufactured utilizing multi-shot or over-molding injection molding technologies. For example, the embodiment of FIGS. 1-6 is produced by shuttle molding by molding connection member 36 in a first injected shot utilizing a first mold core and/or cavity followed by in situ molding of closure base 34 and sealing member 35 in a subsequent shot utilizing a second mold core and/or cavity. In this manner, a very precise and intimate joining of the complementary mechanical interlocking structures between connection member 36 and closure base 34, as well as between the connection member and sealing member 35, can be achieved. Such an intimate joint configuration of a closure could not be achieved or would be very difficult to accomplish by conventional closure manufacturing methods. For example, it is not commercially feasible to mold the sealing member and the closure base separately and then precisely assemble these components in a post-molding assembly operation.
The method of using the tamper-evidencing closure in accordance with the present invention can now be described. In operation and use, when a consumer is ready to access the contents of the container, the consumer will first remove the reclosure cap to access gripping member 63 of the sealing member. With the reclosure cap removed and gripping member 63 readily accessible, the consumer will insert his or her finger through pull-ring 71 and firmly grip the pull-ring. Next the consumer will pull the pull-ring, along with the remainder of sealing member 35, upwardly in such a manner that connection member 36 will tear away from annular bottom 58 of closure base 34. As connection member 36 tears away from annular bottom 58, protrusions 76 will tear away and/or otherwise disengage from recesses 79. Continued pulling of pull-ring 66 will completely disengage sealing member 35 and connection member 36 from closure base 34 thus providing access to the contents of the container.
Once the sealing member is removed, interlocking engagement between connection member 36 and annular bottom 58 is broken by physical separation. Once separated, it is virtually impossible to reassemble or otherwise engage connection member 36 to closure base from which it was separated due to the design of the interengaging structures, that is, the design of protrusions 76 and recesses 79.
In another embodiment of the present invention, closure system 30 a is similar to closure system 30 described above but includes a modified sealing member 35 a and a modified connection member 36 a as shown in FIGS. 7-13. Like reference numerals have been used to describe like components of closure system 30 a and closure system 30.
In this embodiment, connection member 36 a includes a center 84 and a spoke 85 interconnecting center 84 and continuous ring 74 a, as most clearly seen in FIGS. 8 and 10. The spoke configuration of connection member 36 a allows central positioning of a injection molding hot tip. Although only one spoke 85 is illustrated, one should appreciate that one, two, three or more spokes may be utilized to provide a path of material from the center to the continuous ring.
In the embodiment of FIGS. 7-13, recesses 79 a are in the form of channels which extend outwardly along a bottom surface of annular bottom 58 a and upwardly, along an outer surface of inner skirt 56 a, and to an annular seal 87 that is monolithically formed with connecting member 36 a. As shown in FIG. 11, the annular seal extends up and around the upper portion of container neck 57 a and provides a significant sealing surface. Optionally, annular seal 87 is provided with one or more sealing beads 88 to provide improved sealing performance.
With reference to FIG. 10, membrane 62 a of sealing member 35 a has a dome shape. The dome configuration of the membrane allows greater sealing force under vacuum and/or hot-fill applications. For example, the vacuum created within container 31 a during the application process may tend to draw membrane 62 a downward. With the plug seal configuration of the present invention, such downward force and/or motion may cause the outer perimeter membrane 62 a to slightly expand whereby a lower portion of inner skirt 56 a will exert a force against the insider surface of container neck 57 a and thus improve sealing performance.
In operation and use, closure system 30 a is used in substantially the same manner as closure system 30 discussed above.
In another embodiment of the present invention, closure system 30 b is similar to closure systems 30 and 30 a described above but includes an integral sealing and connection member generally designated by the numeral 91, hereinafter integral member 91, as shown in FIGS. 14 and 15. Like reference numerals have been used to describe like components of closure system 30 b and closure systems 30 and 30 a.
In this embodiment, integral member 91 incorporates membrane 62 b and gripping member 63 b as well as protrusions 76 b in a monolithically formed component. Preferably, integral member 91 is formed of polypropylene, high-density polyethylene (HDPE), low-density polyethylene (LDPE), or a thermoplastic elastomer (TPE). One should appreciate that other suitable materials can be used to form the integral member in accordance with the present invention.
Membrane 62 b of integral member 91 substantially seals the aperture formed by inner edge 61 b in a manner similar to that discussed above with reference to the embodiment shown in FIGS. 7-13. Likewise, protrusions 76 b releasably and mechanically interconnect membrane 62 b and closure base 34 b in a manner similar to that discussed above. The monolithic configuration of integral member 91 may simplify the design and production of the closure system, however, one will appreciate that the integral member must have sufficient structural integrity that protrusions 76 b will yield and separate from the corresponding structure of closure base 34 b before gripping member 63 b fails and is torn away from membrane 62 b.
One will also appreciate that the integral member may take other forms and configurations in accordance with the present invention. For example, an integral member may be formed by monolithically forming sealing member 35 and connection member 36 as a single component that is releasably connected to closure base 34. Alternatively, an integral member may be formed by monolithically forming connection member 36 and closure base 34 as a single component in which case sealing member 35 is releasably connected to the integral member.
In operation and use, closure system 30 b is used in substantially the same manner as closure systems 30 and 30 a discussed above.
In yet another embodiment, closure system 30 c is similar to closure systems 30, 30 a and 30 b described above but includes a retainer 49 c used in combination with a monolithically-formed closure base, sealing member and connecting member, hereinafter fitment member 95, as shown in FIG. 16. Like reference numerals have been used to describe like components of closure system 30 c and closure systems 30, 30 a and 30 b.
In this embodiment, fitment member 95 includes a connecting member in the form of a circular line of weakness 96 that interconnects sealing member 35 c and closure base 34 c in a manner similar to a conventional fitment of the type disclosed by U.S. Pat. No. 6,464,096 to Adams et al, the entire content of which is incorporated herein by this reference. In the illustrated embodiment, the circular line of weakness is formed by a downward facing groove, however, one will appreciate that an upward facing groove may be utilized. Preferably, fitment member 95 is formed of low-density polyethylene (LDPE), however, one should appreciate that other suitable materials can be used to form the fitment member in accordance with the present invention.
In this embodiment, retainer 49 c includes gussets 51 c that are modified in that the gussets include an upper spiked edge 99 extending above the top edge of retaining band 50 c. The spiked configuration of gussets 51 c not only allows the gussets to cooperate with corresponding structure on the container neck spaced radially inward from retaining band 50 c but also allows the gussets to cooperate with corresponding structure on the container neck that is axially space above retaining band 50 c.
Unlike prior fitments, fitment member 95 is applied to a container such that retainer 49 c engages the container in a snap-on manner similar to that of retainer 49 discussed above. In operation and use, closure system 30 c is used in substantially the same manner as closure systems 30, 30 a and 30 b discussed above.
In another embodiment of the present invention shown in FIGS. 17-25, closure system 30 d is similar to those described above but includes a modified closure base 34 d. Like reference numerals have been used to describe like components of closure system 30 d and those of the closure systems described above.
In this embodiment, closure system 34 d and sealing member 35 d are monolithically formed and are interconnected by a line of weakness 96 d in a manner similar to that discussed above. One will appreciate that one or more of the following features of closure system 30 d may be utilized on any one of the closure systems described above.
In this embodiment, closure base 34 d includes a retainer in the form of a plurality of retaining flaps 99 which extend radially inwardly and upwardly from a lower portion 48 d of outer skirt 40 d thus forming a J-shaped structure that is dimensioned and configured to cooperate with a locking surface of the container (e.g., locking surface 52 a shown in FIG. 10 and locking surface 52 d shown in FIG. 21). In the illustrated embodiment, the closure base includes eight retaining flaps, however, one will appreciate that the number of retaining flaps may vary.
Unlike the above described retainers or retaining means, each retaining flap 99 includes an oblique, inwardly directed wing 100 that is dimensioned to closely conform to neck finish 32 d of container 31 d and engage locking surface 52 d of the container neck finish 32 d when the closure base is mounted on the container. As the retaining flaps are relatively flexible, the retaining flaps are hinged with respect to lower portion 48 d, whereby wings 100 initially extend substantially horizontally (see FIG. 19) and upon application to the container, the lower portion of flaps 99 extend substantially vertically (see FIG. 24).
In the illustrated embodiment, wing 100 extends obliquely with respect to the lower portion of retaining flap 99, preferably in the range of approximately 120° to 150°, and more preferably approximately 135°. Wing 100 also includes a curved inner edge 102 and a lower concave face 103. The concave face is dimensioned to closely approximate the outer diameter of the container neck finish below the locking surface (see, e.g., locking surface 52 e in FIG. 21). The concave configuration of the face allows the majority of the inner edge to abut against locking surface instead of tangential contact if the face were flat. Thus, the concave configuration increases the amount of contact between inner edge 102 and locking surface 52 e when closure base 34 d is applied to the container 31 d as compared to prior restraining devices. Furthermore, the dogleg configuration of flap 99 (as shown in FIG. 24) ensures that an inner edge 102 of wing 100 remains positioned below locking surface 52 d.
With reference to FIG. 19, the closure base is also provided with a plurality of circumferentially spaced biasing ribs 104 that extend radially inward from an inner surface of outer skirt 40 d. The biasing ribs 104 are dimensioned and configured to abut against and bias retaining flaps 99 inwardly such that inner edge 102 of wing 100 remains below locking surface 52 d. The provision of biasing ribs 104 may also minimize the amount of material necessary to form the closure base. For example, since the biasing ribs 104 abut against and thus bias wings 100 inwardly, the wall thickness of flaps 99 and wings 100 need not be sufficiently thick to provide a rigid member.
Each retaining flap 99 includes a gusset 51 d that is dimensioned to cooperate with anti-rotation structure 105 located on neck finish 32 d of container 31 d. As shown in FIG. 20, anti-rotation structure 105 includes a plurality of teeth 106 circumferentially spaced about the neck finish of container 31 d below the locking surface 52 d. As the effective inner diameter of gussets 51 d is less than the effective outer diameter of teeth 106, gussets 51 d will abut against a respective tooth 106 and thus prevent rotation of closure base 34 d with respect to the neck finish of container 31 d.
The anti-rotation configuration not only facilitates removal of reclosure cap 45 d from closure base 34 d, the anti-rotation configuration also prevents removal of the closure base 34 d from the container 31 d. As one familiar with the field of closures will appreciate, removal of a snap-on closure may be facilitated by twisting or rotating the snap-on closure relative to the container while axially pulling the snap-on closure away from the container. Thus, preventing rotation of the closure base will further prevent removal of the closure base from the container.
Closure base 34 d is also provided with a plurality of vertical lines of weakness similar to those described above. In this embodiment, lines of weakness 53 d extend upwardly along lower skirt portion 48 d. In the illustrated embodiment, the lines of weakness extend substantially vertically, however, one will appreciate that the lines of weakness may extend obliquely with respect to the bottom of lower skirt portion. Also, lines of weakness 53 d are provided on an interior surface of lower skirt portion 48 d that extends below retaining flaps 99, however, the lines of weakness may be provided on an external surface of the lower skirt portion. Furthermore, one will appreciate that the lines of weakness may be symmetrically or asymmetrically around the outer skirt.
In this embodiment, the wall thickness of lower skirt portion 48 d is significantly thinner than outer skirt 40 d, and the wall thickness of vertical lines of weakness 53 d is thinner still. Thus, the force required to split lower skirt portion 48 d is minimal whereby substantially any attempt to pry closure base 34 d from the container neck 32 d will cause lower portion 34 d to split along one or more vertical lines of weakness 53 d thus providing visible evidence that the contends of the container may have been accessed and/or tampered with. One will appreciate that the wall thickness of the vertical lines of weakness and the wall thickness of the lower skirt portion may vary in accordance with the present invention. One will appreciate that the number of vertical lines of weakness, and the location (e.g., internal, external, or combination thereof) may also vary.
In this embodiment, annular top 39 d extends inwardly from the top of outer skirt 40 d, as shown in FIG. 19, and allows for a lower-profile reclosure cap configuration. For example, the plug 46 d of reclosure cap 45 d may be dimensioned to provide an interference fit with inner skirt 56 d. Such a configuration thus provides a primary sealing surface, once sealing member 35 is removed, between reclosure cap 45 d and closure base 34 d that is closer to the container aperture.
In operation and use, closure system 30 d is used in substantially the same manner as the closure systems discussed above.
In another embodiment of the present invention shown in FIGS. 26-30, closure system 30 e is similar in some aspects to those described above but includes a low-profile closure base that is designed for use with containers having a relatively wide-profile opening. Like reference numerals have been used to describe like components of closure system 30 e and those of the closure systems described above.
Closure system 30 e is dimensioned and configured such that it may be used with containers having a relatively low profile and a relatively large container opening. For example, closure system 30 e may be used in combination with cosmetics containers, however, one will appreciate that closure system 30 e may be used in combination with other types of containers including, but not limited to, beverage containers.
As shown in FIG. 26, closure system 30 e includes a closure base 34 e that is adapted for mounting on the container, a sealing member 35 e for sealing the container opening and thus the contents of the container, and a connection member 36 e for releasably connecting the sealing member 35 e to the closure base 34 e.
With reference to FIGS. 29 and 30, closure base 34 e includes an annular top 39 e and an outer skirt 40 e depending downwardly from an outer periphery of annular top 39. A lower portion of skirt 40 e includes retaining structure in the form of a retaining bead 109 which securely mounts closure base 34 e on a container in a well known manner.
As most clearly shown in FIGS. 29 and 30, closure system 30 e also includes a sealing member 35 e which is dimensioned and configured to substantially seal the aperture formed by inner edge 61 e of the closure base and thus seal the container. Sealing member 35 e generally includes a relatively thin membrane 62 e and a gripping member 63 e. Membrane 62 e has an outer diameter that is slightly less than the inner diameter of the aperture formed by inner edge 61 e.
In the illustrated embodiment, gripping member 63 e in the form of a pull-ring 71 e that is connected to membrane 62 e by post 72 e and forms a generally circular loop. The loop is dimensioned to receive the finger of a consumer thus allowing the consumer to grip and pull the pull-ring in order to remove sealing member 35 e from closure base 34 e.
Connection member 36 e connects and joins membrane 62 e of sealing member 35 e to annular ring 58 e of closure base 34 e in such a way that the connection member sealingly bonds but does not integrally bond to at least one of the sealing member and the closure base, namely, the component is formed of the different material.
In this embodiment, connection member 36 e includes a center 84 e and a plurality of spokes 85 e interconnecting center 84 e and a continuous ring 74 e, as most clearly seen in FIG. 27. The spoke configuration of connection member 36 e allows central positioning of a injection molding hot tip. Although four spokes 85 e are illustrated, one should appreciate that one, two, three or more spokes may be utilized to provide a path of material from the center to the continuous ring.
Frangible bridges 110 may be provided, however, that extend between closure base 34 e and sealing member 35 e. The frangible bridges may serve to provide a path for material to flow during the molding process from the sealing member to the closure base (and/or vise versa) and/or to position sealing member with respect to the closure base.
Preferably, closure system 34 e is manufactured utilizing multi-shot or over-molding injection molding technologies. For example, closure base 34 e and sealing member 35 e are formed with a first injected shot utilizing a first mold core and/or cavity followed by in situ molding of connecting member 36 e in a subsequent shot utilizing a second mold core and/or cavity. In this manner, a very precise and intimate joining of the complementary mechanical interlocking structures between connection member 36 and closure base 34, as well as between the connection member and sealing member 35, can be achieved.
In operation and use, closure system 30 e is used in substantially the same manner as those discussed above.
In another embodiment of the present invention shown in FIGS. 31-33, closure system 30 f, in some aspects, is similar to those described above. Like reference numerals have been used to describe like components of closure system 30 f and those of the closure systems described above.
As shown in FIG. 31, closure system 30 f includes a closure base 34 f that is adapted for mounting on the container, a sealing member 35 f for sealing the opening and thus the contents of the container, and a connection member 36 f for releasably connecting the sealing member 35 f to the closure base 34 f.
With reference to FIGS. 31 and 32, closure base 34 f is in the form of an annular ring 113 that is applied to a container about the opening thereof. The annular ring may be adhered, heat sealed, or otherwise affixed to the container by suitable well-known means.
As most clearly shown in FIGS. 29 and 30, closure system 30 f also includes a sealing member 35 f which is dimensioned and configured to substantially seal the aperture formed between inner edge 61 f of the closure base and the outer periphery of membrane 62 f of the sealing member, and thusly seal the container. Sealing member 35 f generally includes a relatively thin membrane 62 f and a gripping member 63 f. Membrane 62 f has an outer diameter that is slightly less than the inner diameter of the aperture formed by inner edge 61 f.
In the illustrated embodiment, gripping member 63 f in the form of a pull tab 114 that is connected to membrane 62 f adjacent the perimeter thereof. The tab is dimensioned to allow a consumer to grip and pull the pull tab in order to remove sealing member 35 f from closure base 34 f.
Connection member 36 f connects and joins membrane 62 f of sealing member 35 f to annular ring 58 f of closure base 34 f in such a way that the connection member sealingly bonds but does not integrally bond to at least one of the sealing member and the closure base, namely, the connection member is formed of the different material.
With reference to FIG. 33, connection member 36 f includes a continuous ring 74 f which extend circumferentially around the sealing member and fills the void between the sealing member and the closure base 34 f. The connection member 36 also includes an upper flange 116 and a lower flange 117 which provide the connection member with a substantially I-shaped cross-section. The I-shaped configuration enhances the structural integrity of the mechanical joint by providing opposing channels that receive and thus engage the closure base and the sealing member, respectively.
In the illustrated embodiment, the upper and lower flanges do not extend completely around the sealing member but instead terminate on either side of the pull tab. Such a discontinuous-configuration facilitates removal of the sealing member. Namely, the amount of force required to initiate separation of the portion of sealing member 35 f immediately adjacent the pull tab from connection member 36 f, and/or connection member 36 f from closure base 34 f, is significantly less than the amount of force which would be required if this portion of the connection member were channel or I-shaped. One will appreciate that the flanges may extend continuously 360° around the sealing member.
Connection member 36 f also includes a center 84 f and a plurality of spokes 85 f interconnecting center 84 f and a continuous ring 74 f, as most clearly seen in FIG. 32. The spoke configuration of connection member 36 f allows central positioning of a injection molding hot tip in the same manner as discussed above.
Preferably, closure system 34 f is manufactured utilizing multi-shot or over-molding injection molding technologies. For example, closure base 34 f and sealing member 35 f are formed with a first injected shot utilizing a first mold core and/or cavity followed by in situ molding of connecting member 36 f in a subsequent shot utilizing a second mold core and/or cavity. In this manner, a very precise and intimate joining of the complementary mechanical interlocking structures between connection member 36 f and closure base 34 f, as well as between the connection member and sealing member 35 f, can be achieved. To facilitate molding, frangible bridges (not shown) may be provided that extend between closure base 34 f and sealing member 35 f in the same manner discussed above.
In operation and use, closure system 30 f is used in substantially the same manner as those discussed above.
For convenience in explanation and accurate definition in the appended claims, the terms “up” or “upper”, “down” or “lower”, “inner” and “outer”, “vertically” and “horizontally” and other directionally relative terms are used to describe features of the present invention with reference to the positions of such features as displayed in the figures.
In many respects the modifications of the various figures resemble those of preceding modifications and the same reference numerals followed by the subscript “a”, “b”, “c”, etc. designate corresponding parts.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims

1. A method of joining separable components comprising:

providing a first component having first interlocking structure; and

molding a second component in a plastics injection molding process within a mold utilizing a surface of said first interlocking structure of said first component as a portion of the mold, said second component being formed with second interlocking structure complementary to said first interlocking structure which mechanically interlocks said first component and said second component, said mechanical interlock being releasable without fracture of at least one of said first and second interlocking structures.

2. The method of claim 1, wherein said molding step further forms said mechanical interlock to be releasable without fracture of said first and second interlocking structures.

3. The method of claim 2, wherein said molding step further forms said first and second interlocking structures such that the interlocking structures cannot be reassembled after said mechanical interlock has been released.

4. The method of claim 3, wherein said providing step is accomplished by providing said first interlocking structure with a recess having first trapezoidal cross-section and said forming step is accomplished by forming said second interlocking structure with a protrusion having a second trapezoidal cross-section complementary to said first trapezoidal cross-section.

5. A closure for a container comprising:

a first component including a first interlocking structure; and

a second, plastics injection molded component having a second interlocking structure molded in situ against said first interlocking structure and complementary in shape to said first interlocking structure, said second interlocking structure being in mechanical interlocking engagement with said first interlocking structure;

said mechanical interlocking engagement being releasable without fracture of at least one of said first and second interlocking structures.

6. The closure of claim 5, wherein said mechanical interlocking engagement is releasable without fracture of said first and second interlocking structures.

7. The closure of claim 6, wherein said first and second interlocking structures cannot be reassembled after said mechanical interlocking engagement has been released.

8. A tamper-evidencing closure for a container having a container opening, said closure comprising:

a closure base having a dispensing aperture adapted for mounting on the container adjacent the container opening;

a sealing member for closing said dispensing aperture and the container opening; and

a connection member releasably interconnecting said closure base and said sealing member;

wherein one of said closure base and said sealing member is formed of a first material and said connection member is formed of a second material, said second material being more pliable than said first material.

9. The tamper-evidencing closure of claim 8, wherein said closure base further comprises an annular top, a well defined by an inner skirt depending downwardly from an inner perimeter of said annular top, and an annular bottom extending radially inward from said inner skirt, said bottom having a closure aperture for accessing the container opening, said first interlocking structure including a recess located on said annular bottom.

10. The tamper-evidencing closure of claim 9, wherein said recess is an outwardly-extending trapezoidally-shaped recess.

11. The tamper-evidencing closure of claim 10, wherein said closure base further comprises a retainer for securing said closure base to the container.

12. The tamper-evidencing closure of claim 11, wherein said closure base further comprises an outer skirt depending downwardly from an outer periphery of said annular top, said retainer including a retaining band extending inwardly and upwardly from a lower portion of said outer skirt.

13. The tamper-evidencing closure of claim 8, wherein said sealing member comprises a pull-ring.

14. The tamper-evidencing closure of claim 8, wherein one of said sealing member and said connection member comprises a peripheral lip and the other one of said sealing member and said connection member includes a continuous ring having an engagement groove cooperating with said peripheral lip to mechanically interlock said connection member and said sealing member.

15. The tamper-evidencing closure of claim 8, wherein one of said closure base and said connection member includes a recess and the other of said closure base and said connection member includes a protrusion complementary in shape to said recess.

16. The tamper-evidencing closure of claim 15, wherein said protrusion and said recess have trapezoidally-shaped cross-sectional profiles.

17. The tamper-evidencing closure of claim 8, wherein said closure base is polypropylene, high-density polyethylene, and/or low-density polyethylene.

18. The tamper-evidencing closure of claim 8, wherein said sealing member is polypropylene, high-density polyethylene, and/or low-density polyethylene.

19. The tamper-evidencing closure of claim 8, wherein said connection member is low-density polyethylene and/or thermoplastic elastomer.

20. The tamper-evidencing closure of claim 8, wherein said closure is dimensioned and configured for use with a container having a container opening, a neck finish, and a locking surface on said neck finish, said closure further comprising:

a plurality of retaining flaps extending radially inwardly and upwardly from a lower portion of an outer skirt of said closure base, each said retaining flap including an oblique wing having a arcuate inner edge adapted to engage the locking surface of the container;

wherein each wing includes a concave lower surface dimensioned and configured to closely approximate the outer diameter of the neck finish below the locking surface allowing substantially the entire the inner edge to contact the locking surface.

21. The tamper-evidencing closure of claim 20, wherein the neck finish includes anti-rotation structure, said closure further comprising a vertically extending gusset extending along at least one of said flaps and being dimensioned and configured to abut against the anti-rotation structure of the neck finish.

22. The tamper-evidencing closure of claim 20, wherein said closure further includes a plurality of biasing ribs extending radially inward from an inner surface of said outer skirt toward a respective one of said flaps to bias said inner edges into contact with the locking surface of the container.

23. The tamper-evidencing closure of claim 8, wherein said closure further comprises a plurality of lines of weakness extending upwardly along a lower portion of an outer skirt of said closure base, said lines of weakness being dimensioned and configured to split upon at least partial removal of said closure from the container.

24. The tamper-evidencing closure of claim 23, wherein said lines of weakness extend substantially vertically along said lower portion of said outer skirt.

25. A tamper-evidencing closure for a container having a container opening, a neck finish, and a locking surface on said neck finish, said closure comprising:

a closure base having a top and an annular outer skirt depending from a periphery of said top;

a plurality of retaining flaps extending radially inwardly and upwardly from a lower portion of said outer skirt, each said retaining flap including an oblique wing having a arcuate inner edge adapted to engage the locking surface of the container;

wherein each wing includes a concave lower surface dimensioned and configured to closely approximate the outer diameter of the neck finish below the locking surface allowing a majority of the inner edge to contact the locking surface.

26. The tamper-evidencing closure of claim 25, wherein the neck finish includes anti-rotation structure, said closure further comprising a vertically extending gusset extending along at least one of said flaps and being dimensioned and configured to abut against the anti-rotation structure of the neck finish.

27. The tamper-evidencing closure of claim 25, wherein said closure further comprises a plurality of biasing ribs extending radially inward from an inner surface of said outer skirt toward a respective one of said flaps to bias said inner edges into contact with the locking surface of the container when said closure is mounted on the container.

28. The tamper-evidencing closure of claim 25, wherein said closure further comprises a plurality of circumferentially spaced lines of weakness extending substantially vertically along said lower portion of said outer skirt, said lines of weakness being dimensioned and configured to split upon partial removal of said closure from the container.

29. A tamper-evidencing closure for a container having a container opening, a neck finish, and a locking surface on said neck finish, said closure comprising:

a retainer extending radially inwardly and upwardly from a lower portion of said outer skirt; and

a plurality of circumferentially spaced lines of weakness extending biasing ribs extending upwardly along said lower portion of said outer skirt, said lines of weakness being dimensioned and configured to split upon partial removal of said closure from the container.

30. The tamper-evidencing closure of claim 29, wherein said plurality of lines of weakness extend substantially vertically along said lower portion of said outer skirt.

31. The tamper-evidencing closure of claim 29, wherein said plurality of lines of weakness extend substantially parallel to one another.

32. The tamper-evidencing closure of claim 29, wherein said plurality of lines of weakness extend from a bottom edge of said lower portion of said outer skirt.