Patent Application
20090078703
The invention concerns a container comprising a container body having a primary opening which is closed by a metal plate portion acting as a first lid element, wherein the metal plate portion includes a lid tab which is defined by a separation line and which after being broken open opens a discharge opening, and the lid tab has an inclined surface co-operating with a first projection arranged on an opening means movable substantially parallel to the plate portion for applying a force to the lid tab in order to break open the separation line. The invention further concerns a lid for a container of that kind and a method of opening such a container.
Such a container of the general kind set forth is disclosed for example in U.S. Pat. Nos. 3,726,432 and 5,816,427 and in EP 1 265 792 B1. In that case the lid of the container is of such a configuration that a projection of a lid element is moved in the plane of the plate portion and can be guided on an inclined surface on the lid tab so that a force extending substantially in a normal direction relative to the lid tab can be produced, whereby the metal plate portion breaks open along a separation line so that the discharge opening is opened. With such a container of the general kind set forth therefore it is possible to dispense with the breaking-open ring which nowadays is frequently used at least in relation to disposable drinks cans and which in the opening operation is pivoted out of the plane of the plate portion and acts by way of a lever on the lid tab to break open the separation line. With such a container of the general kind set forth however care has to be taken to ensure that the force applied by the co-operation of the projection with the inclined surface is sufficient, even when flexing of the plate portion occurs, to break open the plate portion at the separation line. Such flexing of the plate portion can scarcely be avoided, particularly in the case of the disposable drinks cans which are used nowadays, as the wall thicknesses of the container are very small. Usually, such an inclined surface is provided in the lid plate portion by means of the flank of a bead which is shaped in the metal plate portion. In order to ensure that the plate portion breaks open at the separation line in the opening process and the lid tab is bent out of the plane of the plate portion, the travel distance, governed by the system involved, must be greater than the flexing of the plate portion. In that respect it is advantageous if that travel distance, governed by the system concerned, that is to say the bead height or depth, is as great as possible. However, limits are imposed on just prolonging the bead flank serving as the ramp, as much as may be desired, as the small thickness of the plate portion means that severe deformation of the material of the plate portion occurs as from a given bead height or depth. It is precisely in the region of the separation line however that there is only limited material for shaping the inclined surface as the region of the lid tab is precisely surrounded by the separation line.
The object of the invention is to ensure that, in a container of the general kind set forth, it is possible to provide a sufficiently high force for breaking open the plate portion at the separation line of the lid tab.
That object is already attained by the present invention in a surprisingly simple fashion by a container having the features of claim 1, an associated container lid having the features of claim 20, and a method of opening such a container having the features of claim 21.
In that respect a container according to the invention has a lid tab which includes both a depressed bead and also adjacent thereto a raised bead, wherein the inclined surface is composed at least of a portion of a flank of the depressed bead and at least a portion of a flank of the raised bead.
The fact that the inclined surface, that is to say the ramp along which the projection is guided in the opening operation is composed of the flanks of two beads directed in different directions means that ultimately it is possible to provide a greater ramp length and thus ramp height. In that respect the term ramp height is used to denote the extent of the inclined surface parallel to the axis of the container. The adjacent formation of a depressed bead and a raised bead means that it is possible to precisely compensate for deformation forces and stress which can cause folding of the material so that, with the combination of two oppositely formed beads, it is possible to provide a greater effective ramp height in comparison with the configuration of a raised bead or a depressed bead on the lid tab for providing an inclined surface, acting as a control surface, for the projection. Such a configuration of the container according to the invention is particularly suitable in those cases in which it is not possible to carry out a deep-drawing process with holding-down means (folding holder) in the shaping procedure on the lid, but it is only possible to effect shaping of the lid plate portion with a positive or negative shaping means.
The separation line on the first lid element for defining the lid tab can be for example in the form of a weakening line such as a tear line, but it is also possible for the plate portion to be cut through along the separation line and for the cut subsequently to be closed again for example by applying a plastic material to the inside of the lid in the region of the separation line. In the art a discharge opening prepared in that way is referred to as a ‘post-repair’ opening. In that case, in the opening process, that plastic material layer and therewith the separation line are ruptured by application of the force to the lid tab and subsequently the lid tab is bent inwardly into the container.
The container according to the invention can include a container body of a material which in particular is stable in respect of shape such as metal, plastic material such as polyethylene, cardboard or also a composite material. The plate portion acting as the first lid element for closing the container body is generally made from metal to permit the usual shaping processes to be performed to produce the lid configuration.
The term ‘bead’ is used to generally denote a depression or raised configuration in the plate portion of the lid, the bead height or depth generally being related to the main plane of the plate portion.
A large number of different design configurations are also possible in accordance with the invention for the opening means which is movable substantially parallel to the plate portion and on which the first projection is disposed. By way of example that opening means can be in the form of a linear slider or a rotary slider, wherein the projection performs a linear or a rotary movement, on the control surface.
Advantageous embodiments of the invention are recited in the appendant claims.
In order to provide for the best possible compensation of the stresses in the material in the region of the lid tab during production of the inclined surface, it can be provided that the depressed bead and the raised bead go into each other without a step, wherein the transitional region is formed substantially without a bead bottom. In that respect the flank of the raised bead directly adjoins the flank of the depressed bead, in which respect it may be desirable if both flanks in the transitional region involve the same gradient in relation to the surface of the plate portion.
The bead width, the bead flank and the bead height of the depressed bead and the raised bead respectively can be matched to the respective requirements involved. An oval shape in plan view can be advantageous for example if a projection co-operating with the bead or a flank of the bead is of a predetermined configuration so that the bead is adapted to that configuration or to the curve which the projection describes during the opening movement.
It may be desirable if the bead depth of the depressed bead is substantially equal in magnitude to the bead height of the raised bead. In that case the stresses in the material of the plate portion, which occur by virtue of shaping the beads in the lid tab, can be particularly symmetrically compensated. The stress compensation effect afforded by the adjacent arrangement of the raised and depressed beads also permits in particular a simplified method of manufacturing the container of the invention in the region of the lid as by means thereof it is possible for the depressed bead and the raised bead to be respectively produced in the lid tab in one shaping operation without the use of a hold-down arrangement.
The transmission of force to the lid tab can be adjusted very accurately and in dependence on for example the material of the plate portion of the lid and the thickness thereof, by setting predetermined flank angles for the beads. It has proven to be advantageous for a conventional plate portion if the depressed bead and/or the raised bead in the operative region of the inclined surface with the associated first projection has or have a flank angle of 30° to 70°, in particular 40° to 50°. The flank angle denotes the angle of the flank of the bead relative to the main plane of the lid tab or the surface of the plate portion.
In order to prevent an increased internal pressure in the container increasing the force required to break open the separation line defining the lid tab and thus the necessary ramp height, it may be desirable to provide a venting means connected in respect of motion to the opening means for venting of the container prior to the separation line defining the lid tab being broken open. That ensures that the container is vented before the actual operation of breaking open the separation line and opening the discharge opening. That is desirable in particular in relation to those containers which contain a carbonated drink. As the opening means and the venting means are moved simultaneously and with each other, it is possible with a single movement of one element firstly to vent the container and subsequently then to open the discharge opening by breaking open the separation line defining the lid tab.
It is particularly desirable if the lid tab includes a vent tab which is defined by a separation line extending on the lid tab, wherein the venting means includes a second projection which in the movement of the opening means co-operates with the vent tab to produce a force approximately perpendicular to the plate portion on the vent tab in order to break open the separation line of the vent tab. That design configuration aspect has on the one hand the advantage that, in spite of the provision of a venting means, the plate portion does not have to be designed to provide a further opening as that vent opening is disposed precisely on the lid tab which defines the actual discharge opening. Such a design configuration is particularly advantageous if the container is designed to be re-closable.
To ensure that the vent tab opens the vent opening before the separation line of the lid tab is broken open, it can be provided that the first projection which is arranged at the opening means and which is associated with the inclined surface on the lid tab in its starting position before the separation line of the lid tab is broken open projects into the depressed bead and has therein a free travel, within which the first projection does not contact the inclined surface in the movement of the opening means in the opening direction. In that respect it may be advantageous if the second projection which is arranged on the venting means and which co-operates with the vent tab in its starting position before the separation line of the lid tab is broken open is arranged in the immediate proximity of the vent tab. That structural feature provides that the second projection, during the opening movement, co-operates directly with the vent tab for opening the vent opening before the first projection cc-operates with the inclined surface formed by the depressed and raised beads to open the discharge opening. In that respect the second projection advantageously has a free travel during the opening movement, which is less than that of the first projection.
It may be desirable if the vent tab has a raised bead which in plan view is for example of a circular configuration.
Various measures can be envisaged for connecting the plate portion which includes the lid tab to the container body. For example the plate portion can be connected to the container body by a fold configuration, adhesive means or soldering means.
A particularly compact structure in the region of the lid can be achieved if the opening means which is movable substantially in the plane of the plate portion for applying a force to the lid tab is in the form of a second lid element which is arranged over the first lid element and is mounted rotatably relative thereto, wherein the second lid element has an eccentric opening which can be brought over the discharge opening by rotation of the second lid element. In that respect it may be desirable if the second lid element is of substantially the same radial extent relative to the axis as the first lid element and is rotatable relative to the container body about the axis thereof. In that respect the second lid element can have a peripheral annular groove which receives the container edge and/or an edge of the first lid element, which is in the form of an annular flange or an annular bead, wherein the second lid element is mounted rotatably relative to the container body and the first lid element. The second lid element can include a material of the container body and/or a material of the first lid element.
To permit re-closure of the opened container, it can be provided that disposed between the first and second lid elements outside the separation line of the lid tab is a sealing means, in particular in the form of a bead of a sealing material which extends in peripheral relationship at the edge of the discharge opening. On the other hand it can also be provided that seals having a sealing action together are arranged not only at one of the lid elements but at both lid elements.
To prevent the first projection being moved through the seal and thus damaging it after the separation line of the lid tab has been broken open, upon continuing rotation of the opening means, it can be provided that the first projection at the opening means comes to bear against the edge of the discharge opening, thereby stopping the rotary movement in the opening process. Particularly if the lid is adapted for re-closure of the container, it can be provided that the first projection also comes to bear against the edge of the discharge opening and is stopped in that way if the opening means, after the opening operation, is moved back into the starting position again or therebeyond.
In order to provide the first projection on the opening means, which co-operates with the inclined surface on the lid tab, in a fashion which is easy to manufacture, it can be provided that the first projection is in the form of a depressed bead, in particular a depressed bead in the second lid element, which in a starting position extends with its bead head into a depressed bead on the lid tab.
If the depressed bead and the raised bead of the inclined surface are oval, it may be desirable if they are arranged relative to each other in such a way that the large profile semi-axes are substantially tangential to a circular path on the lid tab. That design configuration is particularly advantageous if the opening means or the second lid element is mounted rotatably about the axis of the container body.
The invention also concerns a container lid for use for a container of a configuration as described. That container lid can include a first and a second lid element which can be of a configuration as described hereinbefore.
The object according to the invention is also attained by a method of opening a container comprising a container body of a material which is stable in respect of shape such as metal, PE or cardboard, having a primary opening which is closed by a metal plate portion as a first lid element, wherein in the opening operation for opening a discharge opening a separation line on the plate portion is broken open, which defines a lid tab, and for breaking open the separation line a first projection arranged on an opening means movable substantially parallel to the plate portion is guided along an inclined surface of the lid tab, whereby a force is produced on the lid tab substantially in a normal direction relative to the plate portion. The method according to the invention is distinguished in that the first projection in the opening operation is guided at least portion-wise along flanks of a depressed bead and a raised bead adjacent thereto. Preferably in the opening operation a venting means is moved together with the opening means in order to vent the container prior to breaking open the separation line of the lid tab. In that respect it may be desirable if a separation line on the lid tab is broken open for venting the container, that separation line defining a vent tab. In that respect the vent tab is broken open before the lid tab is broken open, thereby making the subsequent operation of opening the outlet opening easier.
The invention is described hereinafter by the description of an embodiment of a container according to the invention and further features according to the invention with reference to the accompanying drawings wherein:
a-c show the function of the elements on the can lid with the elements on the rotary lid by a section along line VIII-VIII in
a-d show the function of the elements on the can lid with the elements on the rotary lid by a section along line IX-IX in
The can body 10 comprises tin plate and has a conical bottom portion 11 which goes into a surface for the can to stand on. In the upper region the can 1 tapers to afford a can neck 12, wherein the opening is closed by a plate portion 20 which is in the form of a can lid and which co-operates in that way with a second lid element in the form of a rotary lid in a manner still to be described.
Arranged in the plate portion at a position outside the axis thereof is a circular lid tab 30 defined by an almost closed separation line 27. That separation line 27 is interrupted by a leg hinge 31. After the separation line 27 is broken open, the lid tab 30 opens the discharge opening in the can lid, in which case, in the opening operation, the lid tab is bent downwardly into the interior of the container in a manner to be described hereinafter, but still remains connected to the plate portion by way of the leg hinge 31.
In a first embodiment the separation line 27 is in the form of a score line which acts as a weakening line and which can be broken open by applying a force to the lid tab 30. Arranged within the lid tab 30 is a vent tab 40 defined by a further separation line 39 which is in turn of a configuration like the separation line 27. By virtue of the separation line 39 being broken open, the vent tab 40 opens a vent opening, wherein the vent tab 40 is non-losably secured to a leg hinge 42 in the same manner as the lid tab, even if the vent tab 40 moves downwardly into the can from the lid tab 30. Arranged on the vent tab 40 is an approximately circular raised bead in the form of a projection extending upwardly out of the drawing. The edge of the vent tab 40 and thus the vent opening is completely within the lid tab 30.
In addition two beads 32, 36 which are oval in plan view are arranged in mutually adjacent relationship on the lid tab 30, wherein the long semi-axes thereof are each disposed substantially tangentially on a notional circle identified by IX-IX in the drawing. Starting from the base surface of the plate portion 20 or the lid tab 30 the depressed bead 32 extends projection-like into the interior of the container while the raised bead 36 extends upwardly out of the plane of the plate portion or the lid tab. The two beads 32, 36 are arranged relative to each other in such a way that the flank of the depressed bead 32 goes substantially without a transition into the flank of the raised bead 36, thereby providing a control surface acting as a ramp for a projection in order to generate an approximately axially directed force on the lid tab to break open the separation line 27. The axial height or depth of the beads are the same in the specified example so that ultimately it is possible to provide a ramp height which corresponds to double the height of an individual bead in the direction of the axis of the can.
The rotary lid has a kidney-shaped opening 53 which, by rotation of the rotary lid relative to the can lid, can be aligned with respect to the discharge opening which is afforded by breaking open the separation line 27 and bending the lid tab 30 downwardly. The rotary lid 50 also has radially and peripherally spaced projections 54, 55 which are in the form of depressed beads, that is to say beads which extend into the plane of the drawing and serve as projections which co-operate with the raised bead 41 and the depressed bead 32 and the raised bead 36 respectively in the opening operation. In
Hereinafter reference is made to
If now a rotary movement of the lid 50 is produced in the opening operation, then the projection 55 firstly co-operates with the raised bead of the vent tab 40 by the projection 55 being rotated against the raised bead 41 (see
In a similar fashion
Arranged at the edge of the discharge opening 35 is a sealing bead 26, see also
The depressed bead 32 and the raised bead 36 are arranged adjacent in such a way that they go directly into each other without a step and involve the same slope in the transitional region. The flank angle in the operative region of the inclined surface, that is to say in the region in which the projection 54 is in contact with the flanks 33, 37 is about 45° in the illustrated embodiment.
In the embodiment illustrated in the Figures the separation lines 27, 39 are in the form of score lines so that the metal is weakened there in order to be broken open as described. In an embodiment which is not illustrated, those separation lines can also be produced by the material in the can lid 30 being cut through to define the lid tab and the vent tab and by the plate portion being coated on the inside with plastic material, at least in the region of the cut lines. In that case, the projections 54, 55 co-operate with the respective control surfaces to break open that plastic material layer, in the opening movement of the rotary lid. In that respect it can also be provided that the edges of the opening of the lid tab or the opening of the vent tab respectively are enlarged radially inwardly by shaping, so that both tabs bear from the inside against the enlarged plate portion material. That ensures that even an increased internal pressure in the can cannot have the result that the tabs are moved outwardly beyond the plane of the plate portion, whereby under some circumstances the inwardly disposed plastic material layer could break open at the separation lines.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 060 835.3 | Dec 2005 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/DE2006/002291 | 12/20/2006 | WO | 00 | 10/7/2008 |
