Tamper evident container

[0002] This invention relates generally to containers and more particularly to a container that is constructed in a manner to visually indicate when it has been opened or tampered with.

[0003] There have been a variety of tamper proof and tamper evident containers proposed for use in various applications. For example, in the case of foods, medicines and other consumer products, it is often desirable for the packaging to provide easily noted visual evidence when the package has been opened. The tamper evident packages that have been proposed in the past have generally been characterized by complexity that results in high costs and reliability problems. Further, many containers cannot be effectively closed again after they have been initially opened.

[0004] Containers with detachable tear strips have been proposed in various forms and typically provide a tear strip that must be removed in order to open the container. Thus, the presence of an intact tear strip indicates an unopened container and the absence or partial tearing of the strip indicates tampering. Although this type of construction has achieved some popularity, the techniques that have been used to construct the tear strips have resulted in high costs. Also, adequately closing and sealing the container once it has been opened has been a problem with this type of container construction.

[0005] In accordance with the present invention, a tamper evident container is equipped with a detachable tear strip that must be removed to open the container. The invention is characterized by a container body and a closure having a side wall that fits closely inside of the container body. The closure also includes a flange which is connected with the side wall, preferably by an annular neck. The tear strip is connected with the upper edge of the container body along a line of weakness that facilitates detachment of the tear strip when it is desired to open the container. The flange terminates in a lower edge that is heat sealed to the upper edge of the tear strip.

[0006] The container can be opened by tearing away the tear strip along the line of weakness which connects it with the container body. This also results in rupture of the heat seal so that the closure is released from the container body and can be removed to provide access to the contents of the container. The closure can be replaced on the container with the upper part of the container wall closely sandwiched between the flange on the outside and the closure wall on the inside. The neck on the closure seats on the upper edge of the container wall so that the closure has a tight fit on the container to effectively contain the contents.

[0007] Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.

[0008] In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

[0009] FIG. 1 is a perspective view of a tamper evident container constructed according to a preferred embodiment of the present invention, with the tear strip included on the upper portion of the container body shown partially detached from the container;

[0010] FIG. 2 is a fragmentary sectional view on an enlarged scale taken generally along line 2—2 of FIG. 1 in the direction of the arrows;

[0011] FIG. 3 is a fragmentary sectional view similar to FIG. 2, but showing the closure removed from the container after the tear strip has been detached; and

[0012] FIG. 4 is a fragmentary sectional view similar to FIGS. 2 and 3, but showing the closure replaced on the container after having been initially opened.

[0013] Referring now to the drawings in more detail and initially to FIG. 1, numeral 10 generally designates a container which may be used in a variety of applications, including holding various types of food items and particularly other, smaller containers which may contain foods and other materials. The container 10 includes a hollow container body 12 which holds the contents of the container. The container body has a cylindrical side wall 14 and a bottom 16 which may take the form of a disk closing the bottom of the side wall 14. As best shown in FIGS. 2-4, the side wall 14 of the container body has an upper end portion 18 which terminates in a circular upper edge 20. The container body 12 may be constructed of any suitable material such as paperboard coated with a thermoplastic material.

[0014] With reference to FIGS. 1 and 2 in particular, a detachable tear strip 22 has a lower edge 24 that is connected with the upper edge 20 of the container wall 14 along a circular line of weakness 26 which may be perforated or otherwise weakened. The tear strip 22 essentially forms an upward continuation of the side wall 14 extending above its upper end portion 18. The tear strip 22 also has an upper edge 28. The tear strip 22 is preferably provided with a tab 30 on one end which may be grasped with the fingers in order to detach the tear strip 22 from the container body 12.

[0015] A plug closure which is generally identified by numeral 32 is used to cover the otherwise open top of the container body 12. The closure 32 includes a discoidal lid portion 34 which is substantially flat. The closure 32 has a stepped construction and includes an inclined wall 36 which angles downwardly and outwardly from the outer periphery of the lid portion 34. An annular shoulder 38 extends outwardly from the lower edge of the inclined wall 36. The closure 32 has a cylindrical side wall 40 which extends downwardly from the shoulder 38 and has a size to fit closely inside of the container wall 14, as shown in FIG. 2. The lower edge of the side wall 40 is beveled at 42 to facilitate the fit of the side wall 40 inside of the container wall 14.

[0016] The plug closure 32 has a short annular neck 44 which extends outwardly from the upper edge of the side wall 40 and essentially forms an outer continuation of the shoulder 38. A downwardly extending flange 46 is connected at its upper end with the outer edge of the neck 44. The flange 46 is cylindrical and is spaced outwardly from and parallel to the side wall 40. The flange 46 is spaced away from wall 40 by the neck 44 a distance that is substantially equal to or slightly greater than the thickness dimension T (see FIG. 2) of the container wall 14.

[0017] The flange 46 terminates in a circular lower edge 48 which is adjacent to and connected with the upper edge 28 of the tear strip 22 by a heat scal 50. The closure 32 may be constructed of a suitable material such as paperboard coated with a thermoplastic which can be heated in order to provide the heat seal between the flange edge 48 and the tear strip edge 28.

[0018] In order to initially open the container 10, it is necessary to detach the tear strip 22 from the container body 12 by grasping the tab 30 and tearing the strip 22 away from the container body along the line of weakness 26. As the tear strip 22 is detached, the heat seal 50 is ruptured so that the flange 46 is released from its initial attachment to the tear strip. This releases the closure 34 and allows it to be lifted off of the top of the container body 12, thereby providing access to the contents of the container 10.

[0019] In order to replace the closure 32, it can simply be applied to the upper edge portion 18 of the container wall 14 by fitting the closure wall 40 inside of the container wall 14 with the flange 48 located adjacent to and outwardly of the container wall 14. The closure 32 can be lowered onto the upper edge portion 18 of the container until the underside of the neck 44 seats on the upper edge 20 of the container wall in abutting relationship with it, as shown in FIG. 4. The upper edge portion 18 of the container wall is closely sandwiched between the flange 46 on the outside and the closure wall 40 on the inside, with the seating of the neck 44 on edge 20 enhancing the tight fit of the closure 32 on the container body 12. When the closure 32 is replaced on the container body in this fashion after having been initially removed, it is located at a lower position than its initial position wherein the heat seal 50 holds the flange 46 at the position shown in FIG. 2 well above the edge 20 of the container side wall.

[0020] In this manner, the container 10 is constructed so that the presence of the tear strip 22 in an intact condition provides visual evidence that the container is unopened and has not been tampered with. At the same time, the closure 32 can be easily removed simply by tearing away the tear strip 22. Any remaining contents can be enclosed within the container body 12 by replacing the closure 32 and seating it in the position of FIG. 4 wherein it provides a tight fit on the top of the container to enclose the remaining contents of the container body.

[0021] From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.

[0022] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

[0023] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.