Patent Application
20090283492
The present invention relates to container caps and, more particularly, to tamper-evident caps for containers.
Various types of caps exist for removably sealing containers, such as blow-molded or injection molded containers. One such cap has spiral threads extending along an interior surface which match spiral threads on the exterior of a compatible container neck. The threads enable a “screw-on” placement.
Caps may further provide a tamper-evident means, such as a tear band, that is intended to show evidence if the cap has been tampered with or previously removed. Many tear bands fit about the cap diameter and cooperate with ratchet teeth on the corresponding container neck finish. Typically, the tear band has a pull tab that must first be torn and then removed to permit the end user to twist the cap off from the neck. However, current cap threads and neck finish engagements are not always effective to prevent the removal of the cap without first tearing the tear band. In such case, a so called tamper-evident cap can be removed from and reapplied to a container without leaving any visual evidence that it has been tampered with.
Other tamper-evident bands, such as “drop bands,” are designed to remain on the container. When the cap is twisted the drop band drops down on the neck revealing that it has been separated from the cap. However, the band does not always drop down as it should and instead may falsely appear to be connected with the bottom of the cap when it is not.
In addition to failing to provide visual evidence of a tampering, such configurations are not always effective for self-centering the cap on the container thereby resulting in a potential to cross thread during the capping operations. Thus there is a need to provide a tamper evident cap for containers that attaches and releases with relative ease while preventing the cap to be removed without also tearing the tear band and still providing visual evidence of tearing at point of purchase.
In general, one aspect of the present invention is directed to a container cap including a closure member having an annular wall tapered or conically depending from the periphery of the closure member. At the other end of the depending annular wall is positioned a tamper-evident tear-off band. This band is secured to the annular wall by means of a raised boss at the bottom of the annular wall. The band includes a pull tab and ratchet teeth adapted to cooperatively engage teeth on the neck finish of the container to which it is fit to prevent removal of the cap without first removing the band. According to aspects, the pull tab is positioned within the circumference of the band, and, optionally, has a break-tie securing it to a part of the band. At least one of the teeth has an inner face at an acute angle relative to the bottom rim.
Another aspect of the invention is directed to a neck finish formed having a conical wall that defines an opening therethrough. The wall includes a first end that is typically open to the outside and adapted to receive a cap, and a second end that terminates at the container body. At the first end there is a vertical wall with a lip extending inwardly of the wall and preferably outwardly of the plane of the opening to provide a secondary seal when cooperating with a cap of the present invention.
In another aspect, embodiments of the invention include a bottle cap adapted to cooperatively engage the neck finish. In another aspect, the invention provides a tamper-evident cap having an outwardly conical annular wall in combination with a neck finish having substantially the same angular taper.
Other objects, features, aspects and advantages of the present invention will become better understood or apparent from the following detailed description, drawings, and appended claims of the invention.
As shown in
A visual tamper-evident band 34 extends around the bottom rim 35 of annular depending wall 32. In an embodiment, annular wall 32 tapers outwardly from closure member 31 to band 34 and/or has a generally conical shape. The degree of tapering or conical structure depends, in part, on the dimensions of the container, particularly the neck finish, with which the cap 30 is used. In an example, annular wall 32 tapers at an angle of about 5° to about 20°; and, in specific example, annular wall 32 tapers outwardly to rim 35 at about 8°. In tests involving an approximately 38 millimeter cap, annular walls having an angle greater than above 11° were less effective in providing the advantages of this invention. The angle can be further adjusted for a 28 or 48 millimeter cap, or other sized cap, as such size is commonly referred to in the industry. The taper or conical structure of the cap and neck finish permits the cap to self-center on the neck during the capping process. The cap can be made from plastic such as high or low density polyethylene or any other resilient material that is suitable for securing a cap to a container.
The visual tamper-evident band 34 includes a pull tab 36, extending from a part of the band 34, and ratchet teeth 39 aligned along an interior surface thereof. The band 34 attaches to the bottom rim 35 of the annular wall 32 with at least one boss 37 with a connection sufficient to affix the band thereto while also permitting the band to be torn from the wall to allow removal of the cap from the neck finish. In an example, multiple raised bosses 37 run horizontally radially across the bottom rim 35 of cap 30 and affix to the corresponding ratchet teeth 39. As shown for example in
Pull tab 36 is positioned within the circumference of the band 34 and attached continuous therewith at break-tie 38. Optionally, in an example, a second break-tie joins a top portion of band 34 to the bottom rim 35 of the cap opposite break-tie 38. In an example, the pull tab 36 is upwardly or downwardly extending. The extension of pull tab 36 in combination with the tapering or conical structure of annular wall 32 enables tab 36 to remain generally within the same circumference of the band 34 as shown, for example, in
In an example, a user removes cap 30 by sliding a finger down along annular wall 32 pushing tab 36 outward, and pulling tab 36 away from wall 32 and severing break-tie 38 from a portion of band 34. Absence of break-tie 38 provides the user with visual evidence that the cap has been tampered with or removed.
Ratchet teeth 39 are adapted to engage teeth 58 on the neck finish 50 of a container 10, as shown, for example, in
Cap 30 includes an annular flange 41 positioned on the annular wall 32 proximate to closure member 31. Annular flange 41 extends at an angle β relative to the closure member 31. In an example angle β is in the range of about 30° to about 60°. In another example, angle β is about 45°. According to aspects of the invention, inner face 40 and annular ring flange 41 are located and dimensioned to engage and cooperatively secure cap 30 onto the neck finish of a container. For example as illustrated in
Several sets of helically spaced threads 43 are positioned on the inner surface of annular wall 32 generally extending from the closure member 31 proximate to the annular flange 41 to the bottom rim 35. Each thread 43 has a respective lead opening 44 and tail 45. The threads 43 are tapered toward lead openings 44 and tails 45. The conical or taper design of annular wall 32 and threads 43 helps allow the cap 30 to self center on the neck of a container. Further, the tapered or conical design minimizes the chance that threads would over strip or cross thread. In an example, there are at least five thread leads 44 each one beginning at about 72 degrees around the inner surface of annular wall 32. Preferably, threads 43 extend more than 90 degrees and less than 360 degrees around the inner surface of annular depending wall 32. In an example, threads 43 extend around the inner surface about 180 degrees. According to an aspect of the invention, threads 43 project inwardly from annular wall 32 at an angle γ. Angle γ is in the range of about 30 degrees to about 90 degrees, and, preferably, angle γ is about 60 degrees, plus or minus five degrees.
Depending from closure member 31, is annular valve 48. Annular valve 48 is positioned at a distance from annular wall 32 that will permit insertion of the top portion of a container neck finish to fit therebetween. In an example, the valve 48 is spaced from an internal surface of the annular depending wall at a distance that is sufficient to engage an annular lip on the neck finish. In an example, this joinder creates a corner area 47 for accepting the “updraft” from the top rim of the neck of a container. Typically, the corner area 47 provides a right angle into which the top rim fits sufficiently to create a sealing engagement. In an example, this rim and the top portion of the container neck fit comfortably between the annular flange 41 and annular valve 48. The valve 48 extends to a point near to the start of threads 43. In an example, valve 48 includes a taper 49 which facilitates initial engagement of the valve to the inner periphery of the neck finish of a container opening.
In another example of cap 30, annular valve 48 may be eliminated. In this example it will be preferable to also eliminate annular ring valve 41. With removal of annular valve 48, and preferably ring flange 41, a circular sealing member, not shown, would be positioned substantially with closure member 31 to provide a seal between said closure member and opening 53. The sealing member is preferably a disk made of foils, foam, paper or the like. This example entails an additional step of the sealing member placement prior to the bottle capping operation.
In an example, cap 30 has outer ribs or serrations 46 extending along the exterior of annular wall 32. Generally serrations 46 extend from the perimeter of closure member 31 to the bottom rim 35. According to embodiments, serrations 46 taper toward the bottom rim 35 and have an outer spine that is substantially perpendicular to the plane of the closure member 31. In an example, sets of serrations 46 are positioned equidistant about the circumference of annular wall 32. In an example, each set contains two to four serrations. In an example there are eight sets of serrations, the majority of which sets contain about two, and preferably three, serrations 46. Serrations 46 in combination with threads 43 prevent the cap from nesting when stacked with other caps.
According to aspects of an embodiment, the present invention includes a conical neck finish 50 of a container 10, as illustrated for example in
In an example, when cap 30 is applied to the neck finish 50, annular valve 48 is spaced apart from annular wall 32 a distance which is represented by the difference in the radial distance from the outer edge of annular wall 32 at its closure end and the center of a container neck opening and the inner edge of the lip 57. The outer diameter of valve 48 together with annular flange 41 on the cap enhance sealability of cap closure member 31 by creating pressure on the container neck. In an embodiment, as the valve 48 penetrates the inner diameter 51 pushes inward to opening 53, updraft of 57 deflects inward and vertical wall 55 is pushed outward on the neck. Annular flange 41 actuates on the top portion of vertical wall 55 pushing it back thereby creating a secondary seal.
Positioned adjacent to the second end 56 is at least one set of annular ratchet teeth 58 to provide a tamper evident grip for the cap. Ratchet teeth 58 may be positioned around the entire circumference of the second end 56 of the neck or only a portion thereof. In an embodiment, there are two sets of teeth 58 positioned about end 56 with a flat wall 69 separating them at each end of both. Each set consists of eight to twelve teeth 58, although they need not have an equal number. In an example, each set has ten teeth. In an embodiment, the teeth 58 of two different sets of teeth 58 are positioned in opposing directions to prevent “backing off” the cap from the bottle neck. Ratchet teeth 58 are adapted to cooperatively engage corresponding teeth 39 on the tamper-evident band 34 positioned on the mating cap 30.
In an embodiment of the invention, an annular ring flange 59 is positioned substantially adjacent to the plane in which the annular ratchet teeth 58 are provided. This flange 59 in cooperation with annular lip 57 provides a means for securing the cap to the bottle. In an example, the cap snaps over and locks onto the neck finish.
Helically extending between the annular lip 57 and the annular ring flange 59, are at least three threads 64 leading at points 66 and terminating at points 67, adjacent first end 54 and annular ring flange 59, respectively. Threads 64 are helically spaced in contiguous relationship as shown in
In an example, when cap 30 is applied to the neck finish 50 of a container, the threads of the cap contact the top of the threads of the container neck finish before the valve 48 or flange 41 contact the inside dimension of the container. In an example, cap threads 43 engage the bottle threads 64 before the ratchet teeth 58 engage. The cap threads engage with the rotating of the cap engaging the threads of neck finish and engaging the cap 30. Valve 48 cooperates with flange 41 to seal contents when lip 57 pushes against the valve during engagement of the threads.
The protective rim 70 extends downwardly and outwardly from the ratchet teeth 58. The protective rim 70 protects the tamper-evident band 34 from intrusion, for example, by an object that could be used to dislodge the tamper-evident band 34 without tearing it and enable the cap to release from the container. The neck finish can be made of plastic such as high or low density polyethylene of any other material suitable for use with the contents of the container. The material may be the same as that of the container.
Cap 30 when used in combination with neck finish 50 of the present invention provides a seal that is particularly well suited to standard beverage containers, such as blow molded milk containers. When properly sealed, air will not penetrate through the container opening. Use of the tamper-evident band 34 with break tie 38 makes it extremely difficult, if not impossible, to tamper with the contents of the bottle without indicating evidence thereof on the cap. Use of optional second break-tie provides a further security seal.
The embodiments of the invention shown and described in the above figures are exemplary of numerous embodiments that may be made within the scope of the invention. It is to be understood that the detailed embodiments, figures and examples are presented for elucidation and not limitation. The invention may be otherwise varied, modified or embodied within the scope of the invention as defined in the appended claims.
