This application claims the priority of Swiss Patent Application Nos. 01920/04 and 275/05, which were filed respectively on 19 Nov. 2004 and on 15 Feb. 2005 and the entire disclosures of which are herewith incorporated by reference.
The present invention concerns a method according to claim 1, a processing machine according to claim 9 and a cover ring according to claims 23 and 24.
Packages made of different materials, especially packages made of sheet material, or packages made of hybrid materials, are known and are used in many ways. A mass market exists for many packages, for example, for foods or in the field of colors and oils; however special packages are also requested.
Plastic packages and plastic package parts such as covers, closable spouts, tear-off outlets, threaded closures etc. can be made cheaply by injection molding methods and are suited for the packaging of easily spoiled food materials. Such packages are mechanically rather simple; but nevertheless have complexly shaped parts, often movable parts, which must be made with high precision.
Sheet metal packages have high mechanical stability and serve for the long time storage of different contents such as food materials, colors and paints up to munitions or further for the short or long time protection of their contents. According to the nature of things reclosable sheet metal packages are difficult to make and are rare, especially when the contents after the reclosure are to be reliably isolated and sealed against environmental influences.
Hybrid packages can combine various advantages: a tear off foil associated with the cover can then be first removed when the contents after an eventual long storage period are to be consumed. Above all plastic covers are suited for providing a renewed closure since their comparatively pliant outer surface lies in the way of a sealing element at the edge of the opening of the package if the edge through use or during storage is not very much deformed. Above all in the case of large packages it is accordingly necessary that the package body be rigidly made which, can be achieved if necessary through the use of expensive composite material.
For some applications packaging elements have become known which include a spanning cover carrier, for example, a cover ring made of sheet metal such as tin plate or aluminum, which is covered by a foil. The foil spans over and closes the removal opening of the package. After removal of the foil, a reusable cover can be used as a temporary closure for the removal opening, with the stability of the cover ring influencing the closure effect. Independently of the question of reclosability such cover rings can be formed from sheet metal, for example, by beading onto a package body, with the advantage, that then the need is removed for providing a cover of sheet metal which must either be opened by a can opener or must be made expensively as a scored tear-off cover.
Cover rings of the mentioned kind are preferably made on a linear machine (or also on expensively constructed carrousel machines). Involved in the case of linear machines is an arrangement of processing stations disposed behind one another, which processing stations are connected with one another by a step controlled transport for the parts to be processed and which processing stations are likewise controlled in stepwise manner so that during each step each processing station carries out its working procedure on the then involved work piece.
A known machine of the mentioned kind is shown in
A magazine 3 is provided for the lid rings 20 (
A positioning station 4 is formed as a combination station for several working steps and is illustrated in more detail in
In this station 5 an eventual tongue is provided on the foil blank by folding, so that it lies on the foil blank, and as the case may be an embossing is applied to the foil blank. The station 6, as explained, is the discharge station for the lid rings 20 which each have been covered by a foil.
Instead of the terms “adhering or to adhere” in the state of the art for the present connecting techniques the terms “sealing or to seal” are also used.
The foil blank 30 can consist of a composite foil with different layers; it has in any case, as mentioned above, as one of its outer sides a layer of adhesive, such as polyethylene or polypropylene, etc., which is preferably activateable by heat. It is, however, completely within the bounds of the invention that the adhesive is not applied fixedly to the foil and that it can, for example, be separately delivered. The other layers can be of metallic or non-metallic nature, in keeping with the desired properties of the foil in respect to mechanical rigidity, corrosion resistance or conservation capabilities, etc.
As shown in the figure, the foil blank 30 and the shoulder 23 overlap one another in an overlapping zone indicated by the arrow 31. The adhesive connection 32 is indeed not formed in the entirety of the overlapping zone 31, but only in a connecting zone 33. An outermost edge section 34 of the foil blank 30 remains unsecured by adhesive. The zone 33 and the section 34 are likewise shown by arrows in the figure.
The foil blank 30 covers the opening 25 of the lid ring 20. Although in the figure a rotationally symmetric cover carrier is shown, non-circular, that is oval, rectangular and other shapes, can be covered by a foil blank and used for the mentioned purpose; the teaching according to the invention can be used in unlimited manner on all configurations of covered carriers and is not limited to the round lid ring 20 illustration the figure. The term “lid ring” is to be understood in this wider sense. The overlapping zone 31 has a width of 3 mm and the connecting zone 31 a width of 2 mm, which in the case of a frequent outer diameter of the lid ring 20 of for example 76 mm or even more, permits a bursting pressure (that means a pressure at which the adhesively secured foil blank breaks from the lid ring) of 2 bar or higher.
The figure shows a conveyor dog 17 of the conveyor 2 which support the lid ring 20 for processing. Under the lid ring 20 is a support 40 with a supporting surface 41 for the shoulder 23 of the lid ring 20. When the support 40 moves upwardly it engages the shoulder 23 with the support surface of 41 and lifts the lid ring 20 likewise upwardly.
A foil web 43 is indicated by the broken line and runs transversely through the positioning station 4.
A foil cutting work tool 45 with a knife 46 and a gripper 47 having gripping tongs is so arranged that the foil web 43 runs through the gripping tongs and by a closing movement of these is clamped fast and lifted.
Above the gripping tongs 47 is the knife 46 which has a downwardly facing cutting edge 48. The cutting edge 48 has the shape of the foil blank 30 to be stamped out.
By the gripping of the gripping tongs 47 the foil web 48 is fixed in its position. When the gripping tongs 47 subsequently move upwardly, the foil web 43 comes into contact with the cutting edge 48; when the gripping tongs 48 moves still further upwardly, the knife 46 stamps the foil blank 30 from the foil web 43. The circumference of the foil blank 30 corresponds to the outer contour of the cutting edge 48.
Further illustrated in the figure is a positioning means formed as a stamp 50 for the foil blank 30 with an effective outer surface region 51, and a low pressure section 42 surrounded by the region 51, in which low pressure section 52 a low pressure is created by the sucking away of air through a conductor not illustrated in the figure.
During the stamping procedure the stamp 50 is arranged at an upper end position so that with respect to the gripping tongs and the knife 46 its effective surface region 51 lies in the plane defined by the cutting edge 48 of the knife 46. The foil web 43 during the stamping procedure lies next to the outer surface area 51. The simultaneous activation of a low pressure in the low pressure section 52 has the result that the stamped out foil blank 30 remains held to the outer surface area 51. The stamp 50 now moves with the held foil blank 30 downwardly into its lower end position and positions the foil blank 30 in the adhering position onto the shoulder 23 of the lid ring 20 resting on the support 40. The stamp 50 and the support 40 are at this time in their adhering positions and clamped between themselves, by way of their outer surface area which directly face one another, namely the outer surface region 51 and the support surface 41, are the foil blank 30 and the lid ring 20 which are now in contact with one another for an adhesion joining. Heating elements not illustrated in the drawing, which preferably are arranged in the support 40 and in the stamp 50 create the needed heat so that in this adhesion position of the foil blank 30 and the seal ring 20 the adhesive layer of the foil is fluidized and enables the adhesion of the foil blank to the lid ring. In this procedure the stamp 50 and the support 40 work as means for the adhesion or gluing of the foil blank 30 and the lid ring 22 one another.
According to the kind of foil used and the amount of adhesive used for the adhering step additional pressure may be applied to the connecting zone 33. By a corresponding drive the stamp 30 is pressed with the needed force against the blank 30 between the outer surface areas 41 and 51.
Together the support 40 an the stamp 50 move away from one another so that the conveyor 2 can bring a new lid ring 20 into the working position and so that at the same time the lid ring 20 now covered by the foil blank 30 can be taken from the station 4, so that then again the support 40 and stamp 50 can be moved to stamp out a foil blank 30, to position it on the lid ring 20 and to subsequently adhere the blank and ring to one another.
It is especially advantageous in the configuration illustrated in
A disadvantage of the configuration shown in
Accordingly it is the object of the present invention to provide a processing machine allowing a stepping rate of more than 100 steps per minute.
This object is solved by a method according to claim 1 and by a processing machine according to claim 9.
Therefore in that the adhering procedure is broken up into several partial steps, more time is made available for the adhesion itself since it corresponds to one individual timewise step of the processing machine. Therefore, the stepping time can be shortened and the stepping rate increased. Also, since for the positioning of the foil blank 30 onto the lid ring 20 the above described conventional positioning station can be used again, the positioning of the foil blank 30 on the lid ring 20 can be accomplished in a simple way without additional positioning means.
In a preferred embodiment of the method of the invention according to claim 3, in regard to the stated object, an improved lid ring 20 according to claim 23 and an improved foil covered lid ring 20 according to claim 24 can be made. Since the first adhesion step in the positioning station 4 takes place on a predetermined partial area 56 (see
The reduced width of the shoulder effects on one hand a considerable saving of material expense, since in the mass production of packages, the material consumption forms the highest part of the involved costs; and on the other hand, an improved functionality is achieved since the package in use when tipped over can now be better or almost entirely emptied.
As previously stated, the advantages of the invention come into play especially in the case of a processing machine formed as linear machine, since the stepping time is reduced and accordingly the stepping rate can be increased. In the case of a carrousel machine the problem is not so much the stepping time, since the diameter of the carrousel has to be suited to the needed processing time. Where for example on grounds of space the diameter of carrousel is limited, the advantages of the invention also apply analogously to a carrousel machine.
Independently of the processing time and the geometric layout it is evident that as above described by the method according to claim 3 improved lid rings according to claim 23 or claim 24 can also be used newly in a carrousel machine or made in a carrousel machine.
Further implementations, advantages and uses of the invention will be apparent from the dependent claims and from the following description based on the accompanying figures. The figures are:
a a cross section through a lid ring 20 which in the positioning station 4 is adhesively bonded with the foil blank 30 in a predetermined partial region 56 of the connecting zone 33,
b a cross section through the lid ring of
In
Heating means are provided in the pre-warming station 8 which, for example, by induction, preheat the lid rings 20 supplied to the positioning station 4 by the conveyor 2. Likewise the pre-warming station 8′ includes such heating means for the purpose of maintaining heat in the lid rings 20 discharged from the positioning station 4 (which lid rings have already for example have a foil blank 30 adhered to a predetermined partial region of the connecting zone 33), for example to hinder a cooling of the lid rings or to bring them to a desired temperature before they are taken into the further processing station 7 for the supplemental adhesion step.
As in the positioning station 4 in the processing station 7, when the support 49 and the stamp 55 have been moved away from one another, the lid ring 20 can be moved into and between these parts or can be moved out of these parts; likewise the support 49 and the stamp 52 are movable toward one another into the adhering position for the advancement of the adhesion and sealing of the lid ring 20 to and by its foil blank 30 in the adhering position and in contact between the support 49 and stamp 55.
The effective outer surface areas 60, 70 preferably have another shape and geometry as compared to that of the effective outer surface areas 41, 51, and work correspondingly preferably on dissimilar regions of the connecting zone 33 of the lid ring 20 and foil blank 30, as is for example shown in
To clarify the sequentially occurring adhering steps,
Between the broken and the crossed lines the overlapping zone 31 of the shoulder 23 and foil blank 30 is noted. In the illustrated case, and preferably, the overlapping zone 31 corresponds exactly to the connecting zone 33 between the lid ring 20 and foil blank 30. This is different from the conventional lid ring 20 according to
As mentioned,
Heating means (which for simplification of the figure have been omitted) are located in the support 40 and/or in the stamp 50 and heat the outer surfaces 41, 51 facing one another, so that in the covered zone 53, an adhesion is created. Since this covered zone is of less width then the connecting zone 33 there results for the time being an adhesion only in the corresponding predetermined partial region 56 of the connecting zone 33.
Since the sleeve-like shaped knife 46 located inside of the stamp 50 for the stamping out of the foil blank 30 has to be withdrawn, its outer diameter can not be larger than the internal diameter of the knife edge 48 carrying portion of the knife 46, with the result, that the still un-adhered edge section 34 can not be avoided.
b shows the lid ring 20 in the further processing station 7, where the additional adhesion step is carried out. The lid ring 20 in the region of the covered zone 52 is clamped between the support surface 60 of the support 49 and the effective outer surface 70 of the stamp 55. For simplifying the figure the heating means in the support 45 and/or in the stamp 55 for heating the outer surface 60, 70 have been omitted, insofar as such heating is needed for the adhesion. Since the overlapping zone 52 corresponds to the connecting zone 33 (and therefore is wider than the overlapping zone 53), the connecting zone 43 is now entirely adhered and the predetermined partial region 56 (
Preferably, but nor compellingly, the overlapping zone 52 can be of such measurement that a comparatively very small edge region 36 still remains un-adhered, so that during the adhering process at the edge of the connecting zone 33, no flowing mass of adhesive eventually escapes outwardly and dirties the lid ring.
Preferably the connecting zone 33 has a width of 2 mm, which in the case of known foils (for example ALUFIX from Alcan) for stamped foil blanks 30 having a diameter up to 96 mm makes possible a bursting pressure of more than 2 bar. A higher burst pressure is for example necessary, if the packaging contents are to be sterilized.
The thickness of the cutting edge 48 carrying portion of the knife 46 as is to be found in the state of the art and as is illustrated in
In the additional adhesion step the predetermined partial region 56, as already indicated, can without further ado be once again re-adhered (that is, by the heating effect be once again subjected to the adhering process). Alternatively, according to the foil and the used adhesive material the position of the overlapping zone 52 can also be exclusively (or partially) complementary to the predetermined partial region 56, so that the overlapping zone 52 and the predetermined partial region 56 complete the connecting zone 33 (see
By the use of the above described, preferred embodiment of the inventive teaching it is sufficient to form the shoulder 23 of the lid ring 20 with a width of only 2 mm, and in contrast to the state of the art where the necessary shoulder width is 3 mm.
In a further embodiment the connecting zone 33 has a width of less than 2 mm, down to 1.0 mm and the predetermined partial area a width of 1.5 to 0.5 mm.
The subsector A 1 shows the relationship according to
In contrast to this, sector A 2 shows a complementary adhesion, in that after the predetermined partial region 56 a completing partial area 62 is adhered by the further adhering step. A re-adhesion does not take place. The recess zone of stamp 55 and/or the support 49 (in the further processing station 7) corresponds in its contour to the contact effective outer surface region of stamp 50 and/or the support 50 of the positioning station 4, that is of the covered zone 53.
A re-adhesion can be advantageous, if during the first adhesion in the predetermine partial region 56 the adhesion is not completely formed, be this because of a too short a period of time in the processing station 4 or because of an insufficient delivery of heat to the predetermined partial region 56.
An amount of time for remaining in the processing station 4 which is too short for a complete adhesion can be chosen if the stepping rate is so high, which means the period of each step is so short, that the stamping out and positioning of the foil blank 30 consumes too much of the step time remaining available and insufficient heat transfer can then occur if the temperature gradiant has to be chosen to be so high that within the in the remaining step time available an entire thorough warming of the adhesive mass cannot be assured or for different reasons the temperature is below that at which it should be held for a complete fluidizing of the adhesive mass.
A specialist in the art can in a concrete case, that is according to the foil used, the step time, the geometric shape of the predetermined partial region 56 and the required performance of the adhesion (burst pressure), and as the case may be by trials, make a choice between complementary adhesion and re-adhesion (or possibly partial re-adhesion).
Sector B shows a predetermined partial region 57 which no longer lies at the inner edge of the connecting region 33, but which is smaller and displaced toward the middle of connecting region 33. Preferably the width of the partial region 57 is 0.5 mm, but it can also deviate from this value. Such a configuration can be chosen if the foil blank 30 in the positioning station 4 after its positioning is to be only attached and the adhesion is to be principally carried out in the processing station 7. Again the subsector B 1 shows the predetermined partial region 57 as well as the region of the further adhesion 64 in the case of re-adhesion, and the subsector B 2 shows the complementary partial regions 63, 63′ in the case of a complementary adhesion.
Sector C shows several predetermined subregions 58 divided into a regular pattern which are adhered in the positioning station 4. A complementary partial region 65 is then complementarily adhered in the further processing station 7. As in the above examples a complete re-adhesion can also be carried out. Separated, predetermined subregions 58 are created in the effective outer surface region 51 (
Separated outer surface regions 58 can be provided by the specialist in the art, for example, in place of the small unbroken partial region 57 depending on the foil and adhesive parameters. For example then, if a foil in the adhesion process is not inclined to fail, point wise adhesion may be sufficient or indicated for other reasons.
A further implementation possibility is shown in sector D where the predetermined partial region 59 extends along and transversely through the adhesion region 33, which may be of significance in the case of a foil which in the adhesion process or upon the subsequent transport is inclined to failure. The region of the further adhesion 66 can be adhered complementary or by way of re-adhesion. As the case may be in this arrangement an unadhered edge region may be unavoidable or the partial region 59 may not extend over the entire width of the zone 33.
Further, for certain applications it may be beneficial if both the first adhesion in the positioning station 4 and also the second adhesion in the processing station 7 takes place over the entire connecting zone 33, with the consequence, that the entire adhesion connection is made twice. The overlapping zones 52 and 53 are then identical and likewise identical are the recesses in the effective outer surface regions of the stamp and of the support.
In the case of short step times, for example, it is advantageous to preheat the lid ring 20 by the preheating station 8 and to maintain the heat in or to again heat up the lid ring with the partially connected foil blank 30 by way of the preheating station 8′, so that the adhesive mass is optimally heated, preferably almost up to the condition of fluidity, before the further adhesion process is executed.
The invention, although by way of example a linear machine has been explained, is, as above mentioned, not limited to use in a linear machine. The method or the construction of the processing stations can be used in other processing machines, such as a carrousel machine.
It is within the scope of the invention to divide the adhesion process into more than 2 steps and correspondingly still further processing stations can be provided for the additional adhesion steps.
Although the inventive method as well as the inventive apparatus has been explained in connection with the making of a foil blank covered lid ring made of tin plate, these inventions are not limited to tin plate. For example, aluminum or some other shaped materials are suitable for use in the teaching of the invention, including non-metal lid rings, insofar as they have the necessary mechanical properties, for example, in respect to temperature stability.
Moreover not only lids can be covered with foil in accordance with the present invention, but also wall sections of a package, which for example have a ribbed structure, which are to be covered with foil blanks or a foil web.
While in the present application preferred embodiment of the invention have been described it should be clearly noted that the invention is not limited to these and that it can be carried out in other ways within the scope of the following claims.
Number | Date | Country | Kind |
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1920/04 | Nov 2004 | CH | national |
275/05 | Feb 2005 | CH | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CH05/00675 | 11/15/2005 | WO | 00 | 5/16/2007 |