Tamper Indicating Container and Closure

This invention relates to tamper indicating closures and containers by which a tamper indicating ring formed as part of the closure is separated from the closure when an attempt is made to remove the closure thereby indicating tampering.

Tamper indicating closures and containers of a popular type typically employ a closure having an annular skirt with a tamper indicating ring connected thereto by frangible means so that any effort to remove the closure from the container causes the tamper indicating ring to be held against axial movement by engagement of retainer or stop means on the container and on the closure so that the tamper indicating ring separates from the closure giving evidence of an effort to remove the closure and therefore of tampering.

In one form of such tamper indicating closures and containers the stop means on the tamper indicating ring and on the container are in the form of complementary annular beads which engage each other after the closure is first applied to the container to resist removal of the ring from the container. Difficulties are encountered in applying the closure to the container because the interference of the beads on the container and closure sometimes results in premature fracture of the frangible means by which a tamper indicating ring is attached to the closure. In an effort to avoid this problem, attempts have been made to substitute flexible stop means or fingers or annular flanges for the fixed bead on the tamper indicating ring. An example of such structure can be found in U.S. Pat. No. 4,470,513 to Ostrowsky. In that patent the stop means on the tamper indicating ring are in the form of flexible fingers which engage the beads on the exterior of the container neck after the closure has been applied to the container. Any attempt to remove the closure from the container causes engagement of the free ends of the fingers with the underside of the container bead thereby causing a separation of the tamper indicating ring from the closure to indicate tampering.

Both forms of tamper indicating packages have deficiencies which the present invention overcomes.

The present form of the invention has advantages over the tamper indicating arrangements of the prior art in which beads on a tamper indicating ring cooperate with a bead on a container to resist removal of the tamper indicating ring. In those structures a high torque is required to snap the tamper indicating bead over the container bead and sometimes there is premature fracture of the ring and separation from the closure. In the present form of the invention there is a lower torque or load required to apply the cap to the closure. Also, the correct operation of the tamper indicating mechanism is constant over a relatively wide range of cap dimensions which is not tolerated in package forms employing co-acting beads.

The present form of the invention also has advantages over the form of the closure in the Ostrowsky structure. Such structures require formation of a closure and subsequent operations are required to fold the flexible fingers inwardly and upwardly relative to the closure. In the present form of the invention a large variety of tamper indicating closures can be used and the flexible fingers or retainer can be molded on the container in any position convenient to the molding operation because the fingers are automatically moved to their desired position upon application of the closure to the container so that the second operation of separately folding the fingers is eliminated.

These and other advantages of the invention contribute to satisfaction in use and economy in manufacture and will be more fully understood when considered in connection with the following description of preferred embodiments of the invention shown in the accompanying drawings in which:

FIG. 1 is a perspective view showing a tamper indicating container and closure embodying the invention with the closure separate from the container;

FIG. 2 is a cross-sectional view of the closure and container shown in FIG. 1;

FIG. 3 is a cross-sectional view of the closure and container showing the closure in a closed position on the container; and

FIG. 4 is a view of a container showing another embodiment of the invention .

Referring to the drawings a package embodying the invention is designated generally by the numeral 10 and includes a tamper indicating closure designated 12 and a container generally designated by the numeral 14.

Both the closure 12 and container 14 can be made of any conventional thermoplastic material such as polyvinyl chloride, polyethylene, polyethylene terephtyalate or similar materials. The closure 12 can be produced by injection molding and the thermoplastic container of this invention can be produced by either injection molding or injection blow molding techniques.

The closure 12 has a disk-shaped top wall 16 and an annular depending skirt or sidewall 18. The skirt 18 is provided with fastening means in the form of a thread 20 complementary to and engageable with a thread 22 formed on the neck portion 24 of the container 14.

Although threads 20 and 22 are preferred as the fastening means other means for detachably securing a cap to a container may be used.

The closure 12 is provided with a tamper indicating ring 30 which is disposed below the lower edge of the skirt 18. Typically, the skirt 18 and tamper indicating ring are connected to each other by means of frangible webs 32. The webs 32 form a line of weakening which permits easy fracture and separation of the tamper indicating ring 30 from the remainder of the closure 12.

The lower edge of the tamper indicating ring 30 is provided with an inwardly extending annular lip or flange 34 forming part of the stop or retainer means.

The container 14 of the present invention is formed of thermoplastic material and is provided with retainer means 40 disposed below the container threads 22 and completely encircling the neck portion 24. The retainer means 40 is relatively thin and is flexible relative to the thicker and more rigid neck portion 24. The retainer means 40 extends radially outwardly and downwardly in its as molded condition. The outer edge 42 of the retainer means projects outwardly and radially a distance greater than the internal diameter of the lip or flange 34.

The internal diameter of the lip 34 is no less than and preferably slightly greater than the outer diameter of the threads 22 on the neck portion 24. As a result upon application of the closure 12 to the container 14 the lip 34 passes freely over the threads 22 and after the neck threads 22 and skirt threads 20 engage, turning of the closure 12 to further engage the threads causes the closure 12 to move axially downwardly until a cam surface 44 seen in FIGS. 2 and 3 formed on the bottom of the lip 34 engages the top surfaces of the retainer means 40 causing it to be flexed downwardly relative to the neck portion 24. As the closure 12 approaches a closed position on container 14 the lip 34 passes downwardly beyond the outer edge 42 of the retainer means 40 permitting the retainer means 40 to resiliently return towards its as molded condition and to occupy a position such as that illustrated in FIG. 3. In that position the retainer means 40 is engaged with the top surface 46 of the lip or flange 34. This is the fully closed position of the package 10.

From the fully closed position illustrated in FIG. 3, any effort to remove the closure 12, for example, by unthreading the closure 12, causes the cap to move axially upwardly. However, the tamper indicating ring 30 is held axially fixed by the interference of retainer means 40 with flange 34. As a result the frangible web 20 fracture causing separation of the tamper indicating ring 30 from the remainder of the closure. Further unthreading of the closure 12 permits its complete removal from the neck portion 24 leaving the tamper indicating ring 30 held captive on the neck portion 24 by the retainer means 40. After the closure is returned to its closed position on the container 14 the separation of the tamper indicating ring 30 from the remainder of the closure 14 is evident, thereby indicating a prior opening or an attempt to open the package 10.

Another embodiment of the invention is disclosed in FIG. 4 in which retainer means 50 in the form of a plurality of fingers 52 are substituted for the retainer means 40 disclosed in FIGS. 1 through 3. The fingers 52 serve essentially the same function as the retainer means 40. The fingers have free ends 54 which engage the lip 34 on the tamper indicating ring 30 when the closure 12 is in a closed position on the container 14. An attempt to remove the closure 12 causes the fingers to resist axial upward movement of the tamper indicating ring 30 causing fracture of the webs 32 to place the tamper indicating ring 30 in its tamper indicating condition.

The configuration of the retaining means 40 and the fingers 52 of the retainer means 50 can vary in cross-section so long as they are sufficiently flexible relative to the container neck 14 and are sufficiently resilient to tend to return to an as molded condition so that when they are deflected downwardly and inwardly they tend to return to their as molded condition to locate the free ends or edge 42 or the free ends 54 on the upper surface 46 of the tamper indicating ring 30. The fingers also must be sufficiently stiff to resist upward movement of the ring 30.

Although the retainer means 40 and 50 are disclosed as extending radially outwardly and downwardly they can be molded to extend radially outwardly at any chosen angle to the container neck portion 24 so long as the outer edge 42 or the free ends 54 extend sufficiently to be engaged by the tamper indicating ring 30 during movement of closure 12 to its closed position.

Having thus described my invention, however, many modifications thereto will become apparent to those skilled in the art to which it pertains without deviation from the spirit of the invention as defined by the scope of the appended claims.