WO2005082733A1

WO2005082733A1 - Tamper evident container

Info

Publication number: WO2005082733A1
Application number: PCT/GB2005/000657
Authority: WO
Inventors: Ewan Murray Wilson
Original assignee: Pregis Rigid Packaging Limited
Priority date: 2004-02-25
Filing date: 2005-02-24
Publication date: 2005-09-09
Also published as: GB0404145D0

Abstract

There is provided a tamper evident container (1) having a base (5) and a cover (20). The base (5) has an opening adapted to be closed by the cover (20). The cover (20) and base (5) have respective first and second anchoring formations (16, 42). One of the first and second formations (16, 42) is attached to the container (1) by means of a frangible connection (43). The anchoring formations (16, 42) are adapted to couple together to secure the base (5) and the cover (20) when the container (1) is closed to form a connection that is stronger than the frangible connection (43), such that after the anchoring formations (16, 42) are coupled together to close the container (1), opening the container (1) disrupts the frangible connection (43) leaving the anchoring formations (16, 42) coupled together. Thus the base (5) can be at least partially detached from the cover (20) leaving the disrupted frangible connection (43) to provide evidence that the container (1) has been opened.

Description

"Tamper Evident Container"

The present invention relates to a tamper evident container particularly suitable for foodstuffs .

Conventionally, there are many different types of containers used in the food industry for storing, transporting and showing foodstuffs on the shelves in shops and markets. One problem prevalent in supermarkets is that customers will occasionally attempt to obtain access to the contents of food containers in order to taste the foods. This is clearly undesirable since this action could cause contamination of the foodstuffs and furthermore, other customers do not wish to buy the affected products, and tamper-evident containers have been devised to address this problem.

US Patent Nos . 5145088 and 5507406 disclose known solutions, but it has been found that these and other conventional tamper evident containers have various drawbacks in terms of cost and manufacture, and also that significant proportions of important parts of the container and/or cover are destroyed when the cover is opened for the first time.

In accordance with the present invention there is provided a container having a base and a cover, the base having an opening adapted to be closed by the cover, the cover and base having respective first and second anchoring formations, one of the first and second formations being attached to the container by means of a frangible connection, the anchoring formations being adapted to couple together to secure the base and the cover when the container is closed to form a connection that is stronger than the frangible connection, such that after the anchoring formations are coupled together to close the container, opening the container disrupts the frangible connection leaving the anchoring formations coupled together.

Typically the anchoring formations comprise a socket on one of the base and cover and a protrusion on the other. The socket is typically adapted to receive and retain the protrusion. The socket is typically trapezoid in cross-section, with a narrow neck and a wider base. The protrusion is also typically trapezoid, with a distal end that is wider than the neck of the socket, so that pressing the protrusion into the socket deforms one or both of them, as the wide distal end of the protrusion passes the narrow neck of the socket. The protrusion is typically a tight fit in the socket and after the distal end has passed the neck, separating the socket and the protrusion is typically difficult and requires more force than can be withstood by the frangible connection.

Typically the socket is disposed on the cover and the protrusion is disposed on the base, but this could be reversed.

The socket is typically connected to the lid by means of the frangible connection, so that when the container is opened, the frangible connection between the socket and the lid is disrupted, the cover detaches from the base and the socket, which remains attached to the protrusion on the base and is retained there by means of the tight connection between the socket and the protrusion.

A ridge can be disposed on one of the base and the cover, and a channel to receive the ridge is disposed on the other. As the container is closed and the anchoring formations are engaged, the ridge can be accommodated within the channel. In other embodiments, a rim (preferably on the cover) can engage an undercut (preferably on the base) to reinforce the connection between the base and the cover.

Typically the base and the cover require some distortion of the engaging components before they will connect together, and in preferred embodiments, the cover is slightly oversized with respect to the opening on the base.

Preferably the interengaging walls of the cover and the base (typically in the region of the rim and undercut, and the socket and the protrusion) are set at different angles to one another, thereby increasing the deformation of the lid and base necessary for engagement of the two, which increases the rigidity of the container and the security of the seal. Typically the walls can diverge by 5-15°. In preferred embodiments the cover side wall deviates by 10° from the vertical and the side wall of the base deviates by 15°, giving a difference of 5°.

The base and cover can be connected by a hinge, or can be separate.

Typically the socket and protrusion are located adjacent a handle of the container, so that pulling on the handle exerts force on the container in the region of the frangible connection. Typically the handle or the area surrounding it deforms under the load applied during opening.

Typically the handle and socket are disposed at the edge of the cover, and the frangible connection typically surrounds a rim of the socket.

The socket can be oval, circular, rectangular, or any other suitable shape. Typically the frangible seam can adopt the same shape as the socket, but this is not necessary.

Kiss-cut seams are useful for the frangible connection.

Preferably, the cover and base are formed from resilient material, such as plastic.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: - Figs 1, and 2 show plan and side views of a container; Fig 3 shows a perspective view of a closed container; and Fig 4 shows a perspective view of an opened container.

Figs 1 and 2 show a first embodiment of a clear (see through) container 1 in accordance with the invention. The container is made of plastics material having a slight resistence and is particularly useful for holding foodstuffs such as fruit, vegetables and prepared foods such as salads etc.

The container comprises a base 5 and a cover 20. The base 5 is generally bowl-shaped with a flat bottom. The bowl is stepped to form a ledge 6 extending radially outward from the bowl in a horizontal plane, and a side wall 7 extends upward and radially inward at an angle of 15° (with respect to the vertical) from the outermost edge of the ledge 6. The side wall 7 continues inward and upward to apex 7a, where it then extends radially outward and upward to form a funnel 8 before reaching an outer ledge 9, which extends radially outward in the horizontal plane. A ridge 10 in the shape of an inverted U extends upward from the outer ledge 9.

The outer ledge 9 surrounds the base 5. The ridge 10 extends around a large portion of the base, apart from a region at the back of the container 1 where a hinge 3 connects the base 5 and the cover 20, and a tab region 15 at the side of the container 1. In the region of the hinge 3 and the tab 15 the outer ledge 9 not ridged.

The ridge 10 extends radially inward and upward as shown in Fig 2, to form an undercut facing radially inward.

The tab region 15 is generally flat and has a stud 16 standing proud of the upper surface of the ledge 9. The stud 16 has a generally oval shape in plan view, and is generally trapezoid in cross section, with a narrow base 16b, an apex 16a at its widest point, and a narrowing funnel 16f adjacent to its upper surface. The cover 20 has a generally flat central plate 25. The cover 20 dips downward (when considering the closed container) and radially outward from the central plate 25 to form an annular ridge 26 surrounding the plate 25. The ridge 26 has a radially inner wall 27 formed by the gradually outwardly extending surface of the cover 20; the inner wall 27 meets a horizontal lower wall 28. The horizontal wall 28 meets the radially outermost wall 29 at the apex 26a of the ridge 26. The outer wall 29 extends upward and radially inward at 29a at an angle of 10° (with respect to vertical) toward the central plate 25, before extending radially outward at 29b. The wall 29b meets a generally horizontal annular rim 35 at its radially outermost edge.

The annular rim 35 surrounds the ridge 26. The hinge 3 connects the rim 35 of the cover 20 and the outer ledge 9 of the base 5.

The cover 20 has a tab 40 portion in the annular rim 35 at a region of the periphery of the cover 20 that coincides with the tab 10 on the base 5 when the container 1 is closed. The tab 40 is generally flat with a handle 41 that extends radially outward from the rim 35, and has a socket 42 surrounded by a frangible kiss-cut seam 43. The socket 42 stands proud of the upper surface of the rim 35, and has an opening at its base at the level of the rim 35.

The socket 42 is adapted to receive and retain the stud 16. The socket opening is wider than the upper surface of the stud, but narrower than the apex 16a of the trapezoid section of the stud, so when the two are pressed together as the container is closed, they must deform before the stud 16 can fully enter the socket 42.

When the container 1 is filled and is to be closed, the cover 20 is pivoted about the hinge 3 relative to the base 5, until the ridge 26 on the cover approaches the funnel 8 on the base 5. The cover 20 is pushed down until the apex 26a of the ridge 26 moves past the apex 7a of the side wall 7. The angle between the side wall 7 and the ledge 6 forms an undercut, which secures the cover 20 in place. The cover 20 is over-sized with respect to the base 5, such that the base 5 will stretch somewhat when the cover 20 is closed in order for the base 5 to accommodate the cover 20. The deformation must be maintained while the cover 20 is in place on the base 1. This makes the seal between the cover 20 and the undercut more secure and less prone to leaks, and makes it less likely that the cover 20 will accidentally become detached from the base 5. Also, the resultant forces of tension created in the base and compression exerted on the cover increase the rigidity of the container when it is closed.

The wall 29 of the ridge 26 and the side wall 7 of the base 5 are typically set at different angles. For example, the angles between the side wall 7 of the base 5 is usually more acute than the angle between the wall 29 of the ridge 26 and the vertical. The mismatch of the angles between the walls means that each has to deform to snap together. This mismatch between the angles increases the deformation of the cover 20 and the base 5, and stretches out the walls of the base 5 when the cover 20 is in place as the two wall portions 7 and 29 seek to lie flat against one another in the closed container. This in turn increases the rigidity of the container and the security of the seal.

As the cover 20 is closed and the ridge 26 enters the undercut, the annular rim 35 lies flat on top of the outer ledge 9. The edge of the rim 35 is difficult to access around most of its circumference because of the ridge 10 that surrounds most of the ledge 9 and (in the closed container) most of the rim 35.

In the closed container 1, the tab 40 overlies the tab 15, and the socket 42 is positioned directly above the stud 16 in the tab 15. When the container 1 is to be sealed, the stud is pressed into the socket so that the two deform to allow the apex 16a to pass through the opening so that the stud 16 is fully received within the socket 42. The stud can be pulled from the socket after it has been inserted, but the force required to achieve this exceeds the force required to disrupt the frangible seam 43. When the container is to be opened, the handle 41 is pulled up as shown in Fig 4. Since the frangible seam 43 is weaker than the connection between the socket 42 and the stud 16, this action disrupts the seam 43 which typically separates allowing the socket 42 to detach from the cover 20 and be retained on the base 5.

The separation of the socket 42 from the rim 35 allows the container to be opened by further pulling on the handle 41. Once the perforation 43 has been broken for the first time the socket 42 cannot be reattached to the rim 35 and this serves as evidence of opening the container, or tampering with it. Thus a retail outlet can tell if the foodstuffs within the container have been accessed before sale.

Clearly the container can be rectangular or any other shape rather than oval. The container may be hinged or may a have separate cover and base. The socket does not need to be on the cover, and the stud does not need to be on the base. The ridge (when present) can optionally extend around the whole of the container, or just part of it.

Modifications and improvements may be made to embodiments of the present invention described herein without departing from the scope of the invention.

Claims

1. A container having a base and a cover, the base having an opening adapted to be closed by the cover, the cover and base having respective first and second anchoring formations, one of the first and second formations being attached to the container by means of a frangible connection, the anchoring formations being adapted to couple together to secure the base and the cover when the container is closed to form a connection that is stronger than the frangible connection, such that after the anchoring formations are coupled together to close the container, opening the container disrupts the frangible connection leaving the anchoring formations coupled together.

2. A container as claimed in claim 1, wherein the anchoring formations comprise a socket on one of the base and cover and a protrusion on the other.

3. A container as claimed in claim 2, wherein the socket is adapted to receive and retain the protrusion.

4. A container as claimed in claim 2 or claim 3, wherein the protrusion is arranged to form a tight connection in the socket so that in a first closed configuration, the protrusion is retained in the socket.

5. A container as claimed in any of claims 2 to 4 , wherein the socket is trapezoid in cross-section, with a neck portion and a wider base relative to the neck portion.

6. A container as claimed in claim 5, wherein the protrusion is trapezoid, with a distal end that is wider than the neck portion of the socket, so that the protrusion is deformably accommodated in the socket in the first closed configuration.

7. A container as claimed in any of claims 2 to 6, wherein the socket is disposed on the cover and the protrusion is disposed on the base.

8. A container as claimed in any of claims 2 to 6, wherein the socket is disposed on the base and the protrusion is disposed on the cover

9. A container as claimed in any of claims 2 to 7, wherein the socket is connected to the cover by means of the frangible connection, such that when the container is moved from a the first closed configuration to a second open configuration, the frangible connection between the socket and the cover is disrupted.

10. A container as claimed in any preceding claim, wherein a ridge is disposed on one of the base and the cover, and a channel to receive the ridge is disposed on the other.

11. A container as claimed in claim 10, wherein in the first closed configuration, the anchoring formations are interengaged and the ridge is accommodated within the channel .

12. A container as claimed in any preceding claim, wherein a rim formed on the cover is arranged to engage an undercut formed on the base to reinforce the connection between the base and the cover in the first closed configuration.

13. A container as claimed in any preceding claim, wherein the cover is oversized with respect to the opening in the base .

14. A container as claimed in any preceding claim, wherein interengaging walls of the cover and the base are set at different angles to one another, thereby requiring deformation of the cover and/or base for interengagement of the walls in the first closed configuration.

15. A container as claimed in claim 14, wherein the interengaging walls diverge by 5-15°.

16. A container as claimed in any of claims 14 or 15, wherein the cover has a side wall which deviates by 10° from the vertical and the base has a side wall which deviates by 15° from the vertical.

17. A container as claimed in any preceding claim, wherein the base and the cover are connected by a hinge .

18. A container as claimed in any of claims 2 to 17, wherein the socket and protrusion are located adjacent a handle of the container, so that in the first closed configuration, pulling on the handle exerts force on the container in the region of the frangible connection.

19. A container as claimed in claim 18, wherein the handle and/or an area surrounding the handle is deformable under applied load.

20. A container as claimed in any of claims 18 or 19, wherein the handle and socket are disposed at an edge of the cover.

21. A container as claimed in any of claims 2 to 20, wherein the frangible connection is the same shape as the socket.

22. A container as claimed in claim 21, wherein the frangible connection surrounds an edge of the socket.

23. A container as claimed in any preceding claim, wherein the frangible connection comprises kiss-cut seams.

24. A container as claimed in any preceding claim, wherein the cover and base are formed from resilient material .

25. A container as claimed in claim 24, wherein the resilient material is plastic.