The present invention relates to a packaging of the kind featured in the preamble of claim 1.
Packagings of this kind are widely used within eg the food industry for packaging foodstuffs. In this connection a need has been identified to provide safety measures that enable the consumer to ascertain that the packaging has not previously been opened by removal of the lid, eg with a view to contaminating the contents. Examples of such will appear from EP 365,823 A, WO96/27534 A and WO 95/ 06600 A. However, none of the prior art solutions have gained a complete footing, which is presumably due to problems in connection with ensuring a desired reliability of the packaging when the lid is refitted, and relatively elevated costs of manufacture.
The present invention provides a simplified and inexpensive packaging that yields improved reliability that unauthorized removal of the lid can be detected, and which is - despite of this - easy to open and allows reliable and sealing attachment of the lid upon renewed fitting. This is obtained by the features stated in the characterising part of claim 1.
Thus, the engaging portions are configured such that the cooperating third and fourth engaging portions provide an attachment force that exceeds the force necessary to rupture the weakening zone.
By means of the features given in claim 2 it becomes possible to provide a particularly sealing closure of the packaging.
By providing the receiving channel of the container with a bottom wall, as featured in claim 3, unauthorized opening of the packaging is rendered even more difficult.
In accordance with feature 6, arrangement of the weakening zone along only about 90% to 95% of the peripheral expanse of the skirt allows a hinge-like connection to be provided between the central portion of the lid and the container.
Configuration of the receiving channel of the container as featured in claim 8 enables a construction that is advantageous from production-technical point of view in that the configuration of the lid skirt enables arrangement of the weakening zone such that it becomes particularly easy to break. By further configuring the packaging as featured in claim 9, it becomes even extremely difficult to obtain unauthorized access to the container interior without such removal of the lid being clearly visible.
The invention will now be described in further detail with reference to two preferred embodiments. In the drawing:
In Figure 1, reference numerals 10 and 50 are used to designate a lid and a container, respectively, according to a first embodiment of the invention and intended for forming a packaging for eg a food product. The container 50 is configured as a circular cylindrical body and has an outer wall 54 and a bottom 52 as shown in Figure 2. Opposite the bottom 52, the wall 54 has a free end 56. As shown in Figure 3 the lid 10 is in a conventional manner configured with a substantially disc-shaped surface portion 12 with an annular skirt 20 that originates therein. The lid 10 and the container 50 are both made of a plastics material.
As shown in Figures 2 and 3, on the outside of the outer wall 54 and adjoining the free end 56 a protrusion 58 is provided that extends along the peripheral wall 54. This protrusion 58 forms a first engaging portion for the packaging, the protrusion 58 as shown in Figure 4 being configured to cooperate in a conventional manner with an engaging portion 28 on the lid 10. The engaging portion 28 that forms a second engaging portion for the packaging is arranged interiorly of an annular receiving channel 21 that is provided on the skirt 20 and is configured for being able to receive said free end 56.
Said receiving channel 21 is more specifically defined by an interior sidewall 22, an exterior sidewall 26 and a bottom wall 24. The exterior sidewall 26 comprises said second engaging portion 28 that might - even very well - be arranged on the interior sidewall 22 by simultaneously arranging the engaging portion 58 on the interior side of the exterior wall 54 of the container instead. Application of the lid 10 makes use of the elastic properties of the plastics material to provide a releasable snap-locking engagement between the first engaging portion 58 and the second engaging portion 28.
In addition to said walls 22, 24 and 26, the annular skirt 20 comprises a lip arranged in extension of the exterior sidewall 26. This lip consists of a first lip portion 30 and a second lip portion 34. As shown in Figure 4, the first lip portion 30 extends substantially perpendicular from the exterior sidewall 26, whereas the second lip portion 34 preferably extends approximately parallel with the exterior sidewall 26. The first lip portion 30 comprises a weakening zone that preferably extends along the entire circumference of the lid 10 and that is provided by the provision of perforations 42 separated by connecting portions 40, as will appear most clearly from Figure 1. However, the weakening zone can be manufactured in many other ways, eg by use of varying material thicknesses. The exterior sidewall 26 of the skirt 20 also has a protruding gripper flap 32 that is shown in further detail in Figure 5. This gripper flap 32 is configured such that a user of the packaging can apply an upwards force to the lid 10 with a view to removing the lid 10 as described more detailed below.
On the outside, the second lip portion 34 of the skirt 20 is provided with a number of oppositely arranged, annular and protruding chins 36 that preferably extend along the entire circumference of the lid 10. These chins 36 combine to form a fourth engaging portion for the packaging, which engaging portion 36 is configured for snap-lockingly engaging with the third engaging portion 64 described below for the packaging while using the elastic properties of the plastics material.
As shown most clearly in Figures 1, 2 and 4, the container 50 also has an annular and upwardly open receiving 60 arranged on the outside of the outer wall 54 below said first engaging portion 58, configured for being able to receive the second lip portion 34 of the skirt 20. The receiving channel 60 is more specifically formed of a portion of the outer wall 54 of the container, a bottom wall 66 and a wall 62. In the receiving channel 60 a number of box-like protrusions 67 are provided that ia provide a convenient reinforcement of the receiving channel 60 in a very simple manner from an manufacturing point of view. Interiorly of the wall 62 of the receiving channel 60 a number of annular, oppositely arranged chins 64 are arranged that constitute a third engagement portion for the packaging.
The mentioned box-like protrusions are downwardly open and each of them has a front wall 68, a top wall 69 and sidewalls 71. As will appear the front walls 68 and the wall 62 of the receiving channel 60 combine to form a groove in which the second lip portion 34 is located when the lid 10 is fitted on the container 50. It will be understood that the wall 62 and the second lip portion 34 are configured and dimensioned such that a powerful attachment is provided of the second lip portion 36, since the force of attachment is preferably selected to be considerably more comprehensive, eg 25-75% more comprehensive, than the force of attachment established by the snap-locking engagement between the first 58 and the second 28 engaging portions. The lip portion 34 is furthermore configured such that the transition from the wall 62 to the lip portion 34 is relatively even such that it is difficult to introduce a tool down towards the chins 36 and thus seek to release the engagement between the third and the fourth engaging portion. Besides, the bottom wall 66 will make it extremely difficult to release the engagement when a tool is introduced from below.
In use of the packaging, the lid 10 is applied following filling of the container since the snap-locking engagements between the first 58 and the second 28 engagement portions and the third 64 and the fourth 36 engaging portion, respectively, are established by depression of the lid. In this context, the top walls 69 of the protrusions 67 can be used to limit depression of the lid 10 when the underside of the lip portion 30 abuts on the top walls 69. As a consequence of the above-described smooth transition between the wall 62 and the second lip portion 34, the circular shape of the wall 62 that makes it difficult to evert the wall 62 outwards, and since the receiving channel 60 is downwardly closed at the bottom wall 66, it will be extremely difficult, without ensuing permanent and visible destruction of the packaging, to release the snap-locking engagement between the third 64 and the fourth 36 engaging portions. Thus it will be extremely difficult to obtain unauthorised access to the contents of the packaging without such access being visible.
In order to gain access to the contents of the packaging the above-described weakening zone with the perforations 42 are, as mentioned, either arranged all the way along the circumference of the lid, or alternatively with an unweakened area opposite said gripper flap 32. Such unweakened area will be able to serve as a hinge connection whereby the surface portion 12 of the lid will at any time be secured to the container 50 via the second lip-shaped portion 34. Due to the weakening zone 42 being arranged in the first lip portion 30 that extends substantially perpendicular to the sidewall 26, an upwardly and relatively well-defined pull in the gripper flap 32 will give rise to rupture of the weakening zone by tearing of the connecting portions 40.
It will be understood that the force necessary to rupture the weakening zone is less comprehensive than the force necessary to interrupt the snap-locking engagement between the third 64 and the fourth 36 engaging portions whereby it is ensured that a pull in the gripper flap 32 does not entail release of the latter engagement. The preferred location for the weakening zone in an area of the lid that extends approximately perpendicular from the container will, as mentioned, give rise to special advantages of the invention, and the described configuration of the receiving channel 60 is convenient in this context. During or simultaneously with rupture of the weakening zone, the snap-locking engagement between the first 58 and the second 28 engagement portions is released, whereby the lid 10 can be removed. Such snap-locking engagement could be re-established by renewed fitting of the lid 10, eg with a view to storage of residual contents in the container.
Figure 6 shows an alternative embodiment of the invention that is particularly suitable in connection with packages having a non-circular cross-section. Thus the shown packaging has a rectangular cross-section and by use of the invention an evenly distributed attachment force can be established on the lid. It is a well-known problem with the known, rectangular packagings that often different forces occur from the lid on the container at the corner areas relative to along the sides. Thus, the sides are generally more resilient than the corner areas.
Figures 6 through 9 use identical reference numerals for corresponding elements as in Figures 1 through 5, the value 100 however being added, since only the elements that deviate considerably constructively from the previously mentioned elements will be subject to further study.
It will appear from Figure 6 that the container 150 also comprises box-shaped protrusions 167 in the receiving groove 160. The protrusions 167 have front walls 168 that are, however, in this embodiment provided with openings 168'. Such openings 168' combine with annular chins 164 located on the opposite wall 162 of the receiving channel 160 to form the third engagement portion of the packaging, as shown in Figures 8 and 9 that show cross-sections along respective lines A and B in Figure 7. The second lip portion 134 of the skirt comprises separate chins 136 and 138 that are arranged on that side of the lip portion 134 that faces outwards and inwards, respectively, relative to the outer wall of the container 150. When the lid 110 is correctly fitted, the chins 138 are configured for snap-lockingly engaging with the apertures 168' of the front walls 168. It will appear that this solution provides a particularly potent attachment of the second lip portion 134 since the presence of the chins 138 will presuppose a relatively large outward deformation of the wall 162 to release this engagement. This configuration of the lip 134 also makes it even more difficult to release the engagement by introduction of a tool into the receiving channel 160.
It will appear from Figures 7, 8 and 9 that the weakening zone comprises perforations 142 configured as elongate areas and as relatively small areas. The connecting portions 140 are preferably arranged such that, the lid 110 fitted on the container 150, they primarily extend above the spaces between the box-shaped protrusions 167. Thereby the lifting force generated when the gripper flap 132 is pulled will primarily be transferred to the chins 164, said chins 138 - by their abutment on the underside of the top walls 169 - serving in particular to prevent that the lip portion 134 is pulled out by means of a tool. For the packaging described with reference to Figures 6 through 9 the same properties apply inasmuch as the mutual strength of the engaging portions and the weakening zone are concerned, as described with reference to Figures 1 through 5.
It will appear from the above, that preferably the engaging portions are arranged continuously along the entire periphery of the packaging, but obviously the engaging portions can extend discontinuously along the periphery, as is the case with eg the chins 138.