P/00/01I Regulation 3.2(2) AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Application No. Lodged; Invention Title: Tamper Evident Means and Container The following statement is a full description of this invention, including the best method of performing it known to: 2 TAMPER EVIDENT MEANS AND CONTAINER FIELD OF THE INVENTION [0001] The present invention is directed to containers and tamper evident means for containers. [0002] In one form, the invention relates to containers for packaged food, such as ice-cream and margarine, and in particular, to containers including a base having a top opening, a id secured on the base and extending across the top opening and a means that provides evidence of tampering with the connection between the lid and the base. [0003] While the invention will be described with particular reference to food containers, the person skilled in the art will appreciate that the invention is not so limited and has a wide range of applications including containers of other types. BACKGROUND OF THE INVENTION [0004] Food containers often comprise a base and a lid that can be opened to provide access to the food and then re-closed. The lid can be securely held in place on the base by any convenient means such as a snap fitting or interference fit. Some container lids can be fully detached from the base while other containers such as those disclosed and claimed in Australian patent application 2010214759 or International patent application PCT/BR97/00030 have a lid that is hinged so that at all times the lid remains attached to the base to prevent its misplacement or possible contamination by foreign material if the lid is separated from the base. [0005] Many containers of the prior art include tamper evident means. This is particularly important for containers used in the retail sale of food because tamper evident means provide consumers with confidence that the connection between the base and lid has remained secure, and that the contents of the container has 3 not been contaminated. One of the problems associated with tamper evident means of the prior art is that the associated container, or parts of the container can be flexed sufficiently to enable access to the contents of the container without affecting the tamper evident means. [0006] Another problem associated with existing containers is that during manufacture there must be precise alignment of the lid and base when the tamper evident means is incorporated into the container. This can be difficult to achieve because containers are manufactured, handled and filled in a fully, or semi-automated fashion by machines. The machines have certain tolerances which provide leeway for imperfections and inherent variability. As a result of these tolerances there can be misalignment during handling of the container on the automated filling lines and/or imprecise alignment when the lid is applied to the base of the container. [0007 Another problem associated with existing tamper evident means is that they are often quite large, or are provided over a large portion of the container and can be difficult and/or expensive to manufacture. For example, conventional tamper evident closures for medium size plastic food containers such as ice cream tubs typically include a frangible strip or section located at the connection between the lid and base. The strip or section must be broken and torn away before the lid can be removed from the base. [00081 Tamper evident features of the prior art often have one or more of the following disadvantages including: * they are difficult to locate for the purposes of opening the container; * they are often not very visible, which counters their effectiveness as a warning that tampering has occurred; 4 * their physical manipulation can be quite difficult, hindering intentional container opening particularly for those who suffer conditions that affect hand movement, such as arthritis; and * users can find it difficult to figure out how to release them and to decide whether they are intended to be discarded or left partially attached to the container. [0009] Accordingly there is a need for improved tamper evident means for containers. [0010] Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art in Australia or elsewhere on or before the priority date of the disclosure and claims herein. [0011] An object of the present invention is to provide an improved tamper evident means and/or an improved container arrangement. [0012] A further object of the present invention is to alleviate at least one disadvantage associated with the prior art. SUMMARY OF THE INVENTION [0013] In a first aspect of the present invention there is provided a means for coupling a first portion of a container to a second portion of a container in a substantially tamper evident manner, the tamper evident means comprising; (i) a relatively rigid first connection between a first portion of the tamper evident means and the first portion of the container, 5 (ii) a frangible second connection between the first portion of the tamper evident and a second portion of the tamper evident means associated with the second portion of the container, and (iii) a third connection between the second portions of the tamper evident means and the second portion of the container, wherein flexing of the third connection will distort or rupture the second connection. [0014] In a second aspect of the present invention there is provided a means for coupling a first portion of a container to a second portion of a container in a substantially tamper evident manner, the tamper evident means comprising; (i) a relatively rigid first connection between a first portion of the tamper evident means and the first portion of the container, (ii) a frangible second connection between the first portion of the tamper evident and a second portion of the tamper evident means associated with the second portion of the container, and (iii) a third connection between the second and third portions of the tamper evident means and the second portion of the container, wherein application of sufficient force to the third portion cause flexing of the second portion at the third connection and distortion or rupture of the second connection. [0015] In a particularly preferred embodiment, the first and second portions of the tamper evident means are located proximate a shoulder or flange that projects from the main body of the first portion and/or second portion of the container. For example part of the peripheral edge of the lid or the base may project from the normal profile of the edge. In a particularly preferred 6 embodiment, when the peripheral edges of the container are rectangular in cross section, the first and second portions of the tamper evident means are proximate a shoulder or flange at a corner of a peripheral edge. The tamper evident means may include a third portion which is typically integral with the second portion and, for example, overhangs the flange or shoulder. [00161 In a third aspect of the present invention there is provided a means for coupling a first portion of a container to a second portion of a container in a substantially tamper evident manner, the tamper evident means comprising; (i) a relatively rigid first connection between a first portion of the tamper evident means and the first portion of the container, (ii) a frangible second connection between the first portion of the tamper evident and a second portion of the tamper evident means associated with the second portion of the container, and (iii) a flange associated with the first portion or the second portion of the tamper evident means, the flange projecting from the first portion or second portion of the container. [0017] Typically, upon rupture of the second connection, at least part of the first portion of the tamper evident means remains attached to the first portion of the container leaving clear visual evidence of tampering. The second and third connections are also typically configured so that even partial separation of the lid and base will cause visible damage to one or both connections. [0018] In a preferred embodiment the first portion of the container is the base, and the second portion of the container is the lid. However it will be readily apparent to the person skilled in the art that the invention could work by inversion wherein the first portion is the lid and the second portion is the base.
7 [00019] Preferably the relatively rigid first connection is formed by a mechanical connection such as a spot weld, barb or hook between the first portion and second portion of the container. For example, the barb or hook could be integral with the first portion of the tamper evident means in the lid and insert into a corresponding hole in the base. The barb or hook could remain in the hole by interference fit, interlocking fit, melt/welding or other adhesive means. [0020] Preferably the second frangible connection is chosen from the group comprising one or more of the following: perforations, weakening or thinning of material comprising the first or second portion of the container, or a membrane applied to or formed integrally with the first or second portion of the container. [0021] The third connection may be configured in a number of different ways. For example, the connection may comprise thinning of the material of construction of the container, or a membrane applied to or formed integrally with the first or second portion of the container. The membrane may be made of any convenient material or combination of materials and may be laminated. Where used herein the reference to the second portion 'flexing' at the third connection is intended to include hinging, rotation, bending or other distortion at the hinge when force is applied to separate the lid and base of the container. [0021] A membrane associated with the second connection may also be associated with the first or third connection of the tamper evident means. [0023] Furthermore, the membrane(s) may have other functions, such as acting as a label or visible tamper indicator. In a particularly preferred embodiment the third connection provides highly visible evidence of tampering by distorting, changing colour or tearing in response to force applied to the tamper evident means. [0024] In a preferred embodiment, the frangible second connection comprises numerous perforations in the second portion of the container that encircle the first connection and define the first portion of the tamper evident means. If force is 8 applied to the third portion to separate the base and lid, the second connection ruptures, leaving the first portion and first connection mechanically coupled to the first portion of the container. [0025] In one embodiment the third portion of the tamper evident means is adjacent the periphery of a lid where it connects with the base of the container. For example, the third portion may comprise a section of the peripheral edge of the lid or base. When force applied to the third portion, there is bending or flexing at the third connection, concomitantly rupturing the second connection. In a particularly preferred embodiment, the second frangible connection can be broken by a user applying pressure from a single finger to the second or third portion of the tamper evident means. The breakage, deformation or other changes to the tamper evident means in the initial opening of the container is subsequently evident to a user of the container. [0026] The lid of the container may be of a type that can be fully removed from the base. Alternatively, the lid may have a hinge provided on one side of the base portion. For example, the lid may be secured to one portion of the base such that it is able to flex or pivot relative to another portion of the base. The flexing or pivoting may be facilitated by a hinge line, with a membrane applied to or formed integrally with a portion of the lid and extending over the hinge line of the lid, to thereby support repeated flexing of the lid about the hinge line. The hinge itself may be a web-type hinge formed integrally with a central web of the lid, or alternatively, the hinge may be a groove extending across the central web of the lid. In this case, the membrane will typically have an initially orientated internal structure which resists damage caused by repeated flexure of the material, In the lid according to the present invention, the provision of the membrane provides support along the hinge line of the lid thereby allowing for the repeated flexure along that hinge line. [0027 According to another aspect, the present invention provides a container base having a lid secured thereto and incorporating tamper evident means, and/or a method of securing the lid to the base and the tamper evident means.
9 Typically, the lid is secured at one or more points proximate the area of contact between the container lid and the base, for example, by welding. One or more of the points at which the lid is secured may include the tamper-evident means. In one form, the lid may be 'welded' at a point which thus forms the relatively rigid connection between the first portion of the tamper evident means and the first portion of the container. [0028] In a particularly preferred embodiment, the peripheral edge of the container lid is configured to form an interference fit with a correspondingly shaped peripheral edge defining the opening in the base. It is important that the when the container is closed, contact between the respective peripheral edges of the lid and base resists leakage of food from the container. [0029] Typically, the tamper evident means is also located proximate the area of contact between the container lid and base. In a particularly preferred embodiment, the tamper evident means is associated with a relatively flat or planar area of the first or second portion of the container. Typically, for rectangular containers the flattened portion is adjacent a corner. [0030] In a further aspect, the present invention provides a method of providing a tamper evident means according to the present invention in plastic container made by a thermoform process. The frangible second connection may be provided by weakening a portion of the plastic container, or by a cutting, laser etching, or drilling process. [0031] Other aspects and preferred aspects are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention. [0032] In essence, in one aspect, the present invention is based on the inventor realizing that a tamper evident means can be provided by a combination of three connections. In another aspect the present invention is based on providing a mechanical barrier which is incorporated in, made from a part of 10 and/or integral with the lid and/or base of a container which, when force is applied, indicates breach in a tamper evident manner. In another aspect, the present invention is based on the inventor realizing that the combination of three connections can be configured to provide a tamper evident means that can be opened using the force from a single finger. In another aspect the present invention is based on utilising a membrane (such as a membrane formed by the manufacturing method known as "in-mould labeling") to provide a connection of a tamper evident means. The membrane may, in one embodiment, be provided as a label or as part of a hinge as well as providing additional tamper evident benefits. [0033] The tamper evident present invention has a number of advantages, such as: * providing a highly visible indicator of container tampering a does not hinder intentional opening of the container, and can be configured for easy opening, applying force by a single finger/thumb; * the manner in which the tamper evident means can be used to open the container is readily understood by users; 0 adaptability for use on a wide range of different shapes of containers, enabling containers to be designed more with customer and/or product needs in mind; and * relatively convenient and/or cost effective to manufacture. [0034] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, 11 since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0035] Further disclosure, objects, advantages and aspects of the present application may be better understood by those skilled in the relevant art by reference to the following description of preferred embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only in which: [0036] Figure 1 illustrates a container having a hinged lid and a tamper evident means having two connections; [0037] Figure 2 illustrates the operation of the hinged lid attached to the base of the container of Figure 1; [0038] Figure 3 illustrates an embodiment of a container and tamper evident means according to the present invention wherein, * Figure 3a is a perspective view of the lid and base of the container including a tamper evident means, 0 Figure 3b is a detailed view of the tamper evident means shown in Figure 3a, 0 Figure 3c is a plan view of the top of the lid of the container of Figure 3a, 0 Figure 3d is a cross sectional view along AA' of Figure 3e, showing how the lid an base of Figure 3a fit together, 12 * Figure 3e is plan view of one side of the container of Figure 3a, * Figure 3b is a plan view of the bottom of the container of Figure 3a, * Figure 3g is a cross sectional view of the tamper evident means of the container of Figure 3f along BB'. [0039] Figure 4 illustrates a further embodiment of a container and tamper evident means according to the present invention wherein, * Figure 4a is a perspective view of the lid and base of the container including a tamper evident means, * Figure 4b is a detailed view of the tamper evident means shown in Figure 4a, * Figure 4c is a cross sectional view through the tamper evident means of the container of Figure 4b. [0040] Figure 5 illustrates a further embodiment of a container and tamper evident means according to the present invention wherein, * Figure 5a is a perspective view of the lid and base of the container including a tamper evident means, a Figure 5b is a detailed view of the tamper evident means shown in Figure 5a, * Figure 5c is a cross sectional view through the tamper evident means of the container of Figure 5b.
13 DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT [0041] Figure 1 illustrates a container comprising two portions, namely an open-topped base I and a hinged lid 3 with a tamper evident means having two connections. [0042] Figure 1 shows that the lid 3 has a central web 11 and a peripheral rim formation 13. The rim formation 9 of the base 1 includes a horizontal flange 15 extending outwardly from an upper edge of the sidewalls 7 and preferably a skirt 17 depending from an outer edge of the flange 15. The rim formation 9 preferably extends around the entire periphery of the base, and may be continuous or only provided at certain locations. [0043] The hinge may enable at least one portion of the lid to pivot or flex relative to another portion of the lid. The hinge may extend across or partially across the lid. The hinge 2 serves to divide the lid into two portions, a hinge portion 21 on one side 40 of the hinge 2 and a lid portion 23 on the other side 41 of the hinge 2. The hinge 2 may be parallel to at least one of the sides 40 or 41. [0044] Figure 2 shows the hinge 2 is provided on one side of the base portion 1. The lid 3 is secured to one portion 42 of the base 1, and is able to flex or pivot relative to another portion 43 of the base. [0045] During the manufacturing process, a flexible membrane 38 is incorporated into lid. The membrane 38 may be a label. The membrane may be itself flexible, providing all or some of the hinging or flexing effect. In one embodiment, the membrane 38 is made of a plastic material having an initially oriented internal structure. The plastic material can also be polypropylene. The membrane may otherwise be a label of paper or other material, depending on the requirements for the lid 3 and/or container 1. This membrane 38 can be attached or secured over the hinge line 2 and thus act to support the lid 3 for repeated flexure along the hinge line 2. This enables the lid portion 23 of the lid 3 to be repeatedly rotated away from the base 1. In a particularly preferred embodiment 14 the membrane 38 visibly distorts, or changes colour or tears in response to being flexed along the hinge line 2. [0046] The two points also fastened the lid 3 to the base 1 in a suitable manner as disclosed herein or as known in the art, such as by ultrasonic means. However, in accordance with an aspect of invention, the point(s) include a tamper evident feature, such as a frangible section. That is, in addition to the fastening points on the lid portion 23 of the lid 3, there are perforations extending through the web 11 of the lid 3. The effect of the perforations is that when a user opens the lid 3 away from the base 1 at the location of the welds 12, the lid will fracture at perforations leaving a piece 45 of the web 11 still welded to the flange 15 of the base 1 (see Figure 1) while the remainder of the lid 3 is flexed open via hinge 38 from the base 1. Material between the individual perforations is broken during opening. This is evident in Figure 1 showing the piece 45, and a corresponding hole 46 where the piece 45 was formerly attached to the lid 3. The container is thus tamper evident, in that once first opened in the manner described above, the fact that its having been opened is readily apparent from the pieces 45 being broken from the lid and remaining attached to the flange 15 of the base, holes 46 in the lid 3 and also by virtue of deformation or fracture of the regions 31 of the skirt of the rim formation 16 of the lid. [0047] Figure 3 illustrates a further embodiment according to the present invention comprising two portions, namely an open-topped base 107 and a lid 103 (which is not hinged in this embodiment) with a single tamper evident means 110 located at one corner of the rectangular container 101. [0048] Figure 3 shows that the lid 103 has a central web 104 and a peripheral rim formation 105. The peripheral rim 106 of the base 107 has a cross sectional shape that is complementary to the cross sectional shape of the peripheral rim 105 of the lid 103, so that the two peripheral rims form an interference fit where they contact, thus sealing the container. In this embodiment, the peripheral rims are generally rectangular, except at one corner where the tamper evident means 15 is located. At this corner the normal profiles of the peripheral rims are changed to incorporate flanges that project from the lid 103 and base 107 respectively. [0049] Figure 3g shows the cross sectional shape of the peripheral rims adjacent the tamper evident means 101 viewed at BB' of Figure 3f. The flange on the lid 103 forms part of the first portion 113 of the tamper evident means 101 which is rigidly connected by welding to the flange 125 of the base 107. A frangible second connection (not visible in this illustration) is located between the first portion 113 and the second portion 115 of the tamper evident means. The third portion of the tamper evident means overhangs the flange, and can be easily accessed for the application of force to open the lid 103. In use, application of force to separate the lid and base at any position along the periphery may cause flexion or distortion at the third connection 121, and rupture of the second connection. Typically the second connection comprises perforations extending through the web 104 of the lid 103. When the webbing between the perforations ruptures and the second portion 115 and third portion 117 of the tamper evident means hinges about the third connection 121, the first portion 113 is left still welded to the 125 the base 107. There is thus evidence of opening of the lid 103. [0050] One of the advantages of the tamper evident means is that it will provide a deterrent or barrier to attempts to tamper with the container, but will not unduly hinder a consumer from deliberately opening the container. Specifically, a consumer need only apply upwards pressure to the third portion 117 using a single finger or thumb to allow the lid to be deliberately removed. [0051] While the tamper evident means in this embodiment is provided at one corner of the container, it will be appreciated that it can be provided at any position along the periphery of the lid or base, and more than one tamper evident means could be included in a container. [0052] Figure 4 illustrates a further embodiment according to the present invention comprising two portions, namely an open-topped base 207 and a lid 203 16 with a single tamper evident means 210 located at one corner of the rectangular container 201. [0053] Figure 4 shows that the lid 203 has a central web 204 and a peripheral rim formation 205. The peripheral rim 206 of the base 207 has a cross sectional shape that is complementary to the cross sectional shape of the peripheral rim 205 of the lid 203, so that the two peripheral rims form an interference fit where they contact, thus sealing the container. Similar to the embodiment shown in Figure 3, the tamper evident means 201 depicted in Figure 4 is located at one corner of the container where the peripheral rim 106 of the base 107 and the peripheral rim 205 of the lid 203 each include a flat tab or flange. In contrast to Figure 3, Figure 4 shows the tamper evident means to form an acute angle relative to the walls of the base 207. The flange on the lid 203 forms part of the first portion 213 of the tamper evident means 201 which is rigidly connected by welding to the flange 225 of the base 207. A frangible second connection (not visible in this illustration) is located between the first portion 213 and the second portion 215 of the tamper evident means. The tamper evident means works in a manner similar to that of the tamper evident means of Figure 3. However one significant difference is that the third connection 221 comprises flexible membrane 216 incorporated into the lid 203, and which also acts as a label. The membrane 216 is flexible, providing all or some of the flexing effect at the third connection 221 and allowing the second portion 215 and third portion 217 of the tamper evident means 210 to be repeatedly rotated about the third connection 221. [0054] Figure 5 illustrates a further embodiment according to the present invention comprising an open-topped base 307 and a lid 303 with a single tamper evident means 310 located at one corner of the rectangular container 301. [0055] Figure 5 shows that the lid 303 has a central web 304 and a peripheral rim formation 305. The peripheral rim 306 of the base 307 has a cross sectional shape that is complementary to the cross sectional shape of the peripheral rim 305 of the lid 303, so that the two peripheral rims form an interference fit where 17 they contact, thus sealing the container. Similar to the embodiment shown in Figure 4, the tamper evident means 301 depicted in Figure 5 is located at one corner of the container where the peripheral rim 306 of the base 307 and the peripheral rim 305 of the lid 303 each include a flat tab or flange. In contrast to Figure 4, Figure 5 shows the first portion 313 to be recessed within the second 315 and third portions 317 of the tamper evident means. The flange on the lid 303 forms part of the first portion 313 of the tamper evident means 301 which is rigidly connected by welding to the flange 325 of the base 307. A frangible second connection 320 is located between the first portion 313 and the second portion 315 of the tamper evident means. The tamper evident means 301 works in a manner similar to that of the tamper evident means of Figure 4. [0056] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth. [0057] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures. For example, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure 18 wooden parts together, whereas a screw employs a helical surface to secure wooden parts together, in the environment of fastening wooden parts, a nail and a screw are equivalent structures. [0058] "Comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof." Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".