Patent Application
20190144171
The present invention relates to a tamper-evident lock for use with a one-piece thermoformed container having a one-step closure.
Lightweight resealable plastic containers, commonly referred to as clam-shell containers, are commonly used in the retail sale of fresh salads and a variety of other food products, and also for storing food items, such as dried fruits, nuts, spices and the like. To avoid problems resulting from tampering with the contents, a reclosable container can be provided with tamper-evident locking features which include structural elements that provide the merchant and customers with a readily apparent means for indicating whether any tampering with the closure of the container has occurred.
For example, U.S. Pat. No. 7,118,003 discloses a transparent, reclosable, plastic clamshell container provided with a tamper-evident feature. The container has a base that defines a storage area and a cover for closing the storage area. The cover has an outwardly extending peripheral flange, and the base has an upper peripheral edge that forms an upwardly projecting bead extending about the perimeter of the base for receiving the peripheral flange of the cover portion. The bead is configured to render the outwardly extending peripheral flange of the cover relatively inaccessible when the container is closed. The base is provided, beneath the peripheral edge, with a circumferential rib which is received in a circumferential groove formed in the cover beneath the peripheral flange in a closed position of the container. The bead hinders the relatively easy separation of the cover and base portion, impeding access to the cover's peripheral flange edge from fingers or any other object that can be used to pry the cover from the base portion. The base and cover have, respectively, projecting tabs substantially parallel to each other and spaced apart when the cover is in position on the base and their projecting ends are connected by a “pull strip” which initially serves as a hinge, but is also the tamper-evident element. The strip, upon being pulled off, severs the integral connection between the cover and base portion. The absence of the strip indicates tampering with the container.
A drawback of the solution proposed in U.S. Pat. No. 7,118,003 is the complicated structure of the lock arrangement. With the base bead extending over the cover flange, repeated closing and opening of the container is made more difficult. Further, the removal of the indicia strip requires an additional effort by a consumer in opening the container. Another drawback of the container disclosed in U.S. Pat. No. 7,118,003 is that it is formed of two separate components which complicate its closing after it has been opened.
A reclosable, transparent plastic clamshell container with a simplified one-step closure is disclosed in U.S. Pat. No. 7,597,206. The container has a base portion for receiving food items and a cover joined by an integral hinge that provides for access and closing of the container. The base, cover and hinge are formed from a single sheet of plastic in a thermoforming step.
The problem addressed by the present invention is to provide an improved thermoformed polymeric container with an easily removable tamper-evident locking closure, the absence of which is readily apparent to merchants and purchasers.
The above problem is addressed and other advantages are achieved by providing a one-piece reclosable thermoformed polymer container having a base for receiving a product, e.g., a consumable product, a cover for closing the base and an integral hinge portion dimensioned and configured to provide for relative movement between the base and the cover for access and closing the container, and a tamper-evident interface formed by two members which form parts of the base and the cover, respectively, extend outwardly from respective periphery of the base and the cover and which securely engage each other in the closed and locked position of the container, with one of the two members being releasably connected to the base or the cover and being separated therefrom upon initial access of the container. The separation of the respective member from the base or the cover indicates that an attempt to open the container has been made.
Generally, the two members are formed as tabs, with one of the tabs having a projecting male element and the other tab having a recess for receiving the projecting male element in a snap-fit interlocking relation. With the projecting male element of one tab being interlocked in the recess of the other tab, a snap-fit lock for fixedly securing the cover to the base in the initial closed position of the container is formed. When the container is initially opened, the tamper-evident member is torn away from the cover or base portion. The tamper-evident member, upon being torn away, removes the locking connection of the cover and base portions, so that the cover can be opened. The snap-fit lock is preferably located opposite the hinge center.
The locking members will be described in relation to a typical one-piece clam shell container. In an embodiment, the upper periphery of the base portion of the container terminates in an outwardly extending circumferential flange, below which is formed an outwardly projecting recess in the wall of the base proximate the circumferential flange and extending around the periphery of the base. The cover also terminates in an outwardly extending circumferential flange that is complementary to the circumferential flange of the base portion. An outwardly projecting ridge is formed in a depending rim that forms part of the cover below the circumferential flange, the projecting ridge being configured and dimensioned to sealingly engage the recess formed in the wall of the base in the closed position. As will be understood by one of ordinary skill in the art, the shape of the container and the particular means by which the cover is sealed joined to the base forms no part of the present invention, since the locking assembly is adaptable for use with a wide variety of such containers.
The pair of tamper-evident locking members for releasably securing the thermoformed cover and base portions of the container together in fluid-tight sealed relation extend from the periphery of the base and cover flanges, respectively, and are dimensioned and configured to closely engage in superposed relation when contents have been placed in the base and the cover is secured to the base. The locking members include:
(a) a male locking member having at least one integrally molded male element projecting upwardly from the surface, and
(b) a female locking member having at least one integrally molded enclosed recess projecting downwardly from the surface. The recess, or recesses, are being configured and dimensioned to receive and engage the corresponding projecting male element(s) in a secure, manually releasable snap-fit arrangement when the cover and base are in their sealed position in preparation for display and sale. The male locking member or the female locking member includes integrally formed laterally extending pull tabs on either side of the engaged portion of the locking member, and the pull tabs and intermediate engaged p on are joined to the periphery of the container along a line of manually separable perforations, so that when the locking members are separated by manually tearing and removing the pull tabs and intermediate engaged locking section along the line of perforations, the container can be opened. In a preferred embodiment, the line of perforations is spaced apart from the periphery of the container to provide a laterally projecting gripping tab dimensioned and configured with projecting elements and/or a textured surface to assist in manually separating the cover from the base.
In the initial closed and locked position of the container, the flanges of the cover and the base securely engage each other preventing any attempt to manually open the container, (e.g., by an individual using his/her fingers), until the releasably connected locking tab is torn away.
The tamper-evident interface according to the present invention provides a readily apparent means for the merchant and/or customers to identify any tampering with the container, while insuring an easy opening of the container by the user.
The novel features of the present invention, which are considered as characteristic of the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects, will be best understood from the following detailed description of a preferred embodiment, when read with reference to the accompanying drawings.
The invention will be further described below with reference to the drawings in:
To facilitate an understanding of the invention, identical numerals have been used, when appropriate, to designate the same or similar elements that are common to all of the figures. Further, unless stated otherwise, the features shown in the figures are not drawn to scale, but are shown for illustrative purposes only.
A one-piece thermoformed reclosable plastic container illustratively disclosed herein includes a base defining a chamber, a cover for closing the base, an integral hinge connecting the base and cover for relative movement, and a tamper-evident locking assembly formed by opposing members extending outwardly from the periphery of the base and cover that are configured to securely engage with each other in an initial closed and locked position of the container. At least one of the two locking members includes an engaged portion that is releasably connected to a periphery of the base and/or the cover and is manually removed when the container is initially opened, making it apparent to the merchant and/or customer that the locking assembly has been opened. The improved tamper-evident lock of the invention will he described in the context of a one-piece thermoformed plastic clam shell container that is illustrated in the series of
Referring now to
Referring to
The integral base 2, cover 3, hinge 4 and locking assembly 5 can be thermoformed from suitable polymeric materials known in the art that are conventionally used for producing clam shell containers.
The snap-fit locking assembly 5 is formed by the engagement of opposing locking members which, in the initial closed position, engage and interlock with each other forming the tamper-evident lock. A first member 10 can be fixedly secured to the base 2 and have an upwardly extending male projecting element 11 which, in the embodiment is shown in the drawings, is rectangular, but the male element can have any geometrical shape, e.g., oval, circular or square. The first member 10 is formed as a tab attached to the edge of the circumferential flange 6 of the base 2. For example, the first member 10 can have, e.g., a shape of a square with rounded corners and with the projection 11 being formed by indenting the tab, as illustratively shown in the drawings, Preferably, the first member 10 is formed together with the base 2 during the molding process.
A second member 12, which is also formed as a tab, is integrally formed as an extension of to the edge of the circumferential flange 8 of the cover 3 along a weakened separation line 14. The second member 12 is provided with a recess 13 complementary to the male projecting element 11, which is received in the secure snap-fit relation. The second member 12 preferably extends laterally beyond the first member 10 in the closed position of the container. In the initial closed position of the container, the circumferential flanges 6 and 8 of the base 2 and cover 3 are likewise securely engaged. For example, preferably one or more pull-tabs 15 extend laterally from the male locking member 11 and/or the female locking member 13 to permit a user to separate the locking members 10 and 12 from each other and open the container 1. The projection 11 and recess 13 are formed by surface areas having a predetermined coefficient of friction such that, when projection is inserted into the recess for the first time, i.e., the snap-fit lock 5 is initially closed, the frictional forces between the projection 11 of the first member and the recess 13 of the second member are greater than the shearing force or other separation forces required to detach the second member 12 from the cover 3 along the weaken line 14. In an embodiment, the female locking member 13 can include one or more indentations 19 formed in its sidewall.
Referring to
The second member 12 is, thus, formed as a pull-off member that is torn off when the cover 3 of the container 1 is initially opened to gain access to the contents after the container has been initially closed and locked. Thus, any disengagement of the second member 12 from the first member 10 and/or from the circumferential flange 8 of the cover 3 is an indication of an authorized or unauthorized opening of the container.
The foregoing description represents one of many possible embodiments of a tamper-evident interface formed by snap-fit lock according to the present invention.
In an alternative embodiment, the first member 10 is fixedly secured to the cover 3, whereas the second member 12 is secured to the base 2 along a weakened separation line 14. Further, the first member 10 can be provided with a recess, while the second member includes the complementary male projecting element. In another aspect, both members 10, 12 can be formed with interlocking tabs which are secured to the respective flanges along respective weakening lines 14.
As will also be apparent to those familiar with the art, while the container 1 shown in the drawings is formed as a bowl, a container of any shape (e.g., a rectilinear tray, box, and the like) can be provided with a tamper-evident locking assembly 5 according to the present invention.
Although the present invention has been shown and described with reference to a preferred embodiment, such is merely illustrative of the present invention and is not to be construed as limiting and various modifications of the present invention will be apparent to those skilled in the art. The scope of the present invention is therefore to be determined by the claims.
