EP1776286A1

EP1776286A1 - Receptacle comprising a lid

Info

Publication number: EP1776286A1
Application number: EP05773895A
Authority: EP
Inventors: Hans Franzen
Original assignee: Huhtamaki Alf Zweigniederlassung der Huhtamaki Deutschland GmbH and Co KG
Current assignee: Huhtamaki Alf Zweigniederlassung der Huhtamaki Deutschland GmbH and Co KG
Priority date: 2004-08-12
Filing date: 2005-08-12
Publication date: 2007-04-25
Anticipated expiration: 2025-08-12
Also published as: EA010245B1; MX2007001771A; CA2576591A1; DE102004039814A1; WO2006018239A1; EP1776286B1; US20070187408A1; EA200700218A1

Abstract

Disclosed are a top shell (1) or bottom shell (2) made from a deep-drawn molded plastic part as well as a receptacle which is composed of the two joined shells. The invention further relates to a method and a device for producing a top shell or bottom shell (1, 2). The aim of the invention is to create a first and a second shell (1, 2) which can be produced inexpensively as a disposable item while allowing the same to be locked together in a fixed but easily removable manner by joining the two shells together so as to create a largely tight receptacle. Said aim is achieved, among other things, by embodying a reducing collar (5) between the holding edge (4) and the pot-type central part (3) on the top shell (1) while disposing at least two identically pitched threads (7a, 7b, 7c, 7d, 7e, 7f) on the inner face (6) of the holding edge (4). The reducing collar (5) delimits the at least two threads (7a, 7b, 7c, 7d, 7e, 7f) on one side while said at least two threads (7a, 7b, 7c, 7d, 7e, 7f) are provided with an open thread inlet (48).

Description

Container with lid

description

The invention relates to a lid shell and a base shell made of a thermoformed plastic molded part and a container composed of two shells. The invention also encompasses a method and an apparatus for producing a lid or bottom tray.

From a combination of a first shell, for example a lid shell, with a second shell, for example a bottom shell, a container is produced in which, in the assembled state, the first shell engages the second shell from the outside, the second shell having a second shell circular opening edge is formed, and in which the first shell with a retaining edge projects beyond the second shell. Such containers are used for storing and transporting small parts of all kinds, especially of foods, such as cream cheese, yogurt and the like, and in the latter of salad compositions that are provided with dressing or to which the dressing must be added. A generic foreign, as produced by injection molding container disclosed in US 5,638,976. The injection molding process offers the advantage that the conditions can be produced with a large variety of variants with respect to their geometry. The disadvantage of this manufacturing method lies in the comparatively high unit costs in the production.

Since the containers are usually disposed of after the contents have been used up, only containers that are particularly inexpensive to produce come into consideration for this purpose, which can be produced by thermoforming from a thermoplastic material. A container made of a thermoformed plastic material with two halves which can be screwed together is described in US Pat. No. 3,322,262. For screwing the first half is provided with an external thread and the second half with an internal thread. This structural design with two complementary matched threads is manufacturing technology but expensive to manufacture. Moreover, the tightness of the container screwed together is realized solely via the threaded connection, which leads to considerable leakage in the case of the unavoidable manufacturing tolerances during deep drawing. This is particularly unacceptable when packaging food.

Conventional resealable containers, for example for Jo¬ ghurt, with simple and inexpensive closure or Ver¬ locking means have a bottom shell with associated De¬ ckelschale, the cover shell in the region of the opening edge has a so-called lid skirt with locking elements, which under the Grab the edge of the bowl. When opening the container, the lid skirt is pulled over the opening edge. To do this, grasp under the cover apron and release the snap lock to remove the cover. This is not only unwieldy, but there is also the danger that the fingers come into contact with the container contents.

Accordingly, it was the object of the invention to provide a first and a second shell, which can be produced inexpensively on the one hand as disposable articles and on the other hand by joining together allow a firm but easily releasable locking to a substantially tight container.

Other subtasks are to develop a method and apparatus for making the first trays. The object is achieved according to the invention with a first shell, spielsweise a cover shell on which a fastening means for Her¬ a threaded connection is arranged, wherein the Befesti¬ supply means between the retaining edge and the cup-shaped Mittel¬ part formed Reduzierbund and at least two the Innensei¬ te of the retaining edge with the same pitch arranged threads comprises, wherein the Reduzierbund the at least two threads bounded on one side and the at least two threads each ei¬ NEN open threaded inlet.

Each thread is bounded in a flange by the Reduzierbund, so that in the transition region from the thread to the Re¬ duzierbund a tapered gusset is formed, in which complementary with the thread cooperating elements of a second shell are fixed by a clamping action. For this purpose, the reducing collar is formed circumferentially with a constant width. Such a clamping attachment is particularly suitable for thermoformed plastic molded parts.

Advantageously, the threads are each diametrically angeord¬ net. This results in a diametrically arranged complementary elements of the second shell, such as holding wings, a uniform distribution around the opening edge clamping effect, combined with a uniformly distributed pressure force of Deckel¬ shell on the bottom shell. This in turn increases the tightness over a longer period of use.

Preferably, the threads have a pitch of 5 ° to 30 °. Even if in principle all pitches of the threads can be realized, this results in the aforementioned range a comparatively small overall height of the retaining edge with a simultaneous low Verschwenkweg for releasing the first and second shell.

It has also proved to be favorable to equip the first shell with a gasket. The seal may be formed, for example, as a concentric circumferential sealing cone on the underside of the first shell between the cup-shaped central part and the Reduzierbund. When assembled first and second shell of the sealing cone is supported against the second shell at its transition region of Öffnungs¬ edge and inner wall and thereby produces a sealing effect. Instead of the encircling sealing cone, this can also be dispensed with and a sealing film can be welded onto the opening edge.

The second shell has a cup wall, which is formed in its upper Ab¬ section with a circular opening edge and is permanently closed in its lower portion with a bottom plate. According to the invention, a fastening means for producing a threaded connection is arranged on the second shell, wherein the fastening means comprises at least two rigid retaining wings projecting radially at the circular opening edge. The term rigid is understood to mean a rigidity which allows a functional opening and closing of the second shell without a reversible or irreversible deformation of the retaining wings.

The retaining wings of the second shell cooperate with the threads of the first shell in such a way that the retaining wings protrude into the threads when joined together and the first and second shell are mutually guided during a rotational movement. The main advantage over known threaded connections lies in the fact that a complex thread that is complementary to the thread of the first shell can be dispensed with at the second shell, as a result of which the outlay during production is markedly reduced. The Halteflügei should be arranged diametrically around the opening edge. This, together with also uniformly distributed in the circumferential direction retaining wings, a uniformly distributed around the opening edge surface pressure between the first and second shell is achieved. This contributes to a good seal and prevents unintentional release of the cover shell of the bottom shell.

With regard to the geometries of the holding wings, a large number of configurations is possible. In a preferred embodiment, the retaining wings have a front edge and trailing edge extending radially relative to the second shell, which edges are connected to one another via an outer edge which is curved concentrically with respect to the second shell.

As an alternative to the embodiment described above, the retaining wings can have a front edge extending radially to the second shell and a convexly curved rear edge.

It has also proved favorable if the retaining wings are formed from a square or polygonal retaining surface projecting beyond the opening edge.

In a further advantageous embodiment, the retaining wings may be formed as a retaining cam.

The further sub-task is solved by a resealable container with a first shell and with a second shell attachable thereto, in which a Reduzierbund is formed between the retaining edge and the pot-like middle part and in which the first and the second shell are screwed together via a threaded connection, wherein the threaded connection to the first Scha¬ le on the inside of the retaining edge at least two threads equal pitch, which are bounded on one side by the Reduzierbund and each having an open threaded inlet, and at the zwei¬ th shell at least two of the circular opening edge radially projecting retaining wings comprises.

The combination of the first shell with a second shell ent¬ is a largely dense container. As a complementary component to the above-described at least two thread turns engage in this radially projecting retaining wing arranged on the second shell.

Preferably, the number of retaining wings is less than or equal to the number of An¬ threads. This facilitates the connection of the first and second shell, without holding wings without an associated thread in the way and cause a locking effect when screwing.

Conveniently, the at least two threads in the circumferential direction of the retaining edge have a greater width than the retaining wings. As a result, in particular in the entrance area of the threaded passages, it is possible to insert the retaining wings in the corresponding thread in an accurate manner.

The first shell may have a nominal diameter in the area of the retaining edge and between the opposing threads which is slightly larger than the full circle diameter of the retaining wing.

It may also be advantageous if the first shell in an area between thread teeth of the threads has an internal diameter which is slightly larger than the outside diameter of the opening edge. By means of the inner diameter of the holding edge, which is larger than the opening edge, it is possible for the second shell to spread over the first shell. Only in the area of the threads is this, with approximately the same wall thickness, visible to the outside. This inner diameter widening is matched to the dimensioning of the retaining wings such that the retaining wings are guided in the thread over the entire length of the thread turn. The inner diameter in the region of the threads should only be selected to be slightly larger than the full circle diameter of the retaining wings so that there is as much overlap as possible between the flank of the respective thread and the retaining wing guided therein.

The sub-task is solved by a deep-drawing process, using a molding tool with a rotatably arranged Haltehül¬ se and a pivotable to the holding sleeve in the circumferential direction threaded sleeve in which initially in a starting position of Halte¬ sleeve and threaded sleeve a slide over the mold, the film is introduced, clamped and formed into the mold for forming a first shell, the threaded sleeve is brought into an end position by being unscrewed and the shell is denied by the retaining sleeve.

The method according to the invention is exclusively the shaping process for creating a shell with a thread located thereon, for example a cover shell. After positioning the film over the mold, the film is preferably acted upon from its upper side with compressed air and nestles against the mold. In this operation, the shell is formed with the threads. To loosen the shell of the mold, in particular of the contours of the threads, the threaded sleeve is spindled. Below this is a preliminary gear understood comparable to a nut and a screw, where the mother is the first shell and the screw is the threaded sleeve. By unscrewing the screw from the nut or the threaded sleeve from the first shell, the threaded sleeve loses contact with the first shell and thereby releases it, so that the first shell can be lifted off the top of the molding tool.

In a preferred embodiment of the method, the shell is held during the unwinding of the retaining sleeve and / or of the film. In principle, it is possible to fix the first shell during unwinding exclusively over the film, thereby preventing the shell from rotating with the threaded sleeve. However, this is problematic, especially in the case of soft or thin materials, since the film can not absorb the forces occurring during unscrewing and deformations occur on the first shell. For this reason, it is advantageous to counter the first shell at least zus¬ Lich also with the retaining sleeve.

In the method described above, the shell can be stripped together with the film from the holding sleeve. In a further step, the film embossed with the first shells is fed to another conventional punching machine and the shells are cut out of the film.

By transporting the film to a punching machine located at a remote location, however, there is a further cooling of the film and the first shells already formed therein, so that a removal does not occur concentrically around the intended shape of the first shell but offset therefrom. This disadvantage occurs especially in the case of materials with high material-related shrinkage in the foreground, for example in the case of polypropylene (PP). The material PP is included Cooling an irregular shrinkage of about 2%. Less critical is a time-delayed separation with polystyrene (PS), which calculably shrinks by a maximum of 0.5%.

For strongly shrinking materials, it is therefore advantageous if the first shell is punched directly out of the film on the molding tool after the threaded sleeve has been spooled out. This reduces the committees to a considerable extent, since now an exact alignment of the shell with the punching tool is possible and an intermediate transport from the forming tool to the punching tool falls.

A qualitatively even more precise concentric shaping can be achieved if the shell is already punched out of the film on the molding tool before the threaded sleeve is unwound. In this case, the first shell, since it is already detached from the film composite prior to unwinding, can be fixed exclusively against the threaded sleeve by means of the retaining sleeve against rotation. For this purpose, the holding sleeve is provided with a geometrical structure which, after the shaping process, is designed to be complementary in the first shell and enables a positive force transmission.

If the first shell is completely dissolved out of the film, it is a form cutting process.

As an alternative, however, it has also proved to be favorable to punch the first shell only partially out of the film and to leave residual webs between the film and the shell. This method is band steel cutting. In this case, forces are at least partially still taken up by the film during unwinding and nevertheless very precise concentric parts are produced. The remaining webs are broken in subsequent stacking processes. One a significant advantage is the lower manufacturing costs compared to the form cutting. A disadvantage compared with the shape cutting lies in the possibly remaining, not completely broken residual webs with dangerous cut edges.

The third sub-task is solved by a molding tool for producing a first shell with a fixed holding sleeve and a sleeve rotatable in the circumferential direction from a starting position to an end position threaded sleeve, wherein in the Ge threaded sleeve contours for forming at least two Gewinde¬ courses are formed ,

Advantageously, a Innenstem¬ pel is arranged centrally within the retaining sleeve. The inner punch is used to shape the inner cup-shaped middle part and can be pushed ver¬ in a particular embodiment alone or together with the retaining sleeve in the axial direction. Due to the displaceability, it is possible after lifting the threaded sleeve, the first shell relative to the Form¬ tool to lift and transported away.

Preferably, the threaded sleeve is arranged concentrically around the holding sleeve, so that the threaded sleeve rotates symmetrically around the holding sleeve during unwinding. The retaining sleeve should be inside and the threaded sleeve outside.

In a favorable embodiment, the holding sleeve has a sloping wall section, in which holding ribs are arranged. Depending on the angle of the inclined wall section, the retaining ribs can be aligned in the axial or radial direction of the retaining sleeve. In each case, the retaining ribs should be as perpendicular as possible to the direction of rotation of the threaded sleeve, so that one of the pivoting movement the threaded sleeve on the shell acting torque is absorbed by the retaining ribs.

For the pure molding process, it is sufficient if a holding device is arranged around the threaded sleeve, with which the film can be clamped outside the mold and thereby fixed. The holding device may comprise, for example, a fixed punching counter and a lowerable holding plate.

In the event that the mold cutting or band steel cutting is to be performed, instead of Halte¬ device a holding and punching device can be arranged circumferentially around the Gewin¬ dehülse.

The mold cutting can be carried out particularly advantageously with a holding and punching device which comprises a stripper plate, a knife plate which can be lowered and a fixed knife sleeve concentrically surrounding the threaded sleeve, the stripper plate and the knife plate being vertically movable. The knife sleeve is preferably arranged between the threaded sleeve and the stripper plate.

With the aid of the lowerable knife plate, the film is clamped between the knife plate after it has passed over the mold. Following the forming process and after unwinding the threaded sleeve, the latter is moved upwards, thereby shearing off the film with the knife plate.

It is particularly favorable if the knife sleeve slightly projects relative to the stripper plate during the process of the film, so that a step forms in the film in the transition of the stripper plate to the knife sleeve, which serves to seal during the shaping process. If the forming process is to be supplemented with the band steel cutting, the holding and punching device can comprise a fixed stamping counterpiece, a lowerable holding plate and a band steel knife which can be lowered to the stamped position. The belt steel blade is a steel strip sharpened on one or both sides, which is closed annularly in the circumferential direction and is formed on its sharpened underside with recesses for the whereabouts of remaining webs. The holding plate for holding the film and the strip steel blade are two separate Bau¬ parts, so that a worn strip steel blade can be exchanged individually in a simple manner. As a result, particularly favorable production costs are possible.

It is particularly advantageous if venting bores are arranged in the retaining sleeve. During deep drawing usually the mold is pressurized from above with compressed air, so that the film conforms to the forming tool and assumes a shell shape. This nestling is supported by the vent holes. It is also possible to connect a vacuum line to the ventilation bores and to suck the film onto the shaping tool.

In a particularly favorable embodiment, the threaded sleeve between the initial and end position during demolding a Ver¬ path of 10% to 25% of its circumference.

The invention will be explained in more detail below with reference to 14 drawing figures. It shows the Fig. 1: a perspective outside view of a first

Shell as a cover shell with circumferential Dichtke¬ gel;

FIG. 2 shows a side view of the first shell according to FIG. 1; FIG.

3 shows a cross section of the first shell according to FIG. 1;

4 shows a detail of an enlarged cross-section of retaining edge, reducing collar, sealing cone and pot-shaped middle part of the first shell as cover shell;

Fig. 5: an external perspective view of a first

Shell as cover shell without sealing cone;

Fig. 6: an external perspective view of a first

Shell as a cover shell with only innen¬ lying rippled structure;

Fig. 7: an external perspective view of a second

Shell as a bottom shell with symmetrically shaped retaining wings;

FIG. 8 shows a plan view of the second shell according to FIG. 7; FIG.

Fig. 9: a side view of the second shell according to

Fig. 7;

Fig. 10; a plan view of a second shell as Boden¬ shell with asymmetrically shaped retaining wings; 11 ac: a partial cross section through a forming tool in various functional positions;

FIGS. 12a-c: a partial cross section through a forming tool in various functional positions for forming cutting;

13 shows a partial plan view of the shaping tool according to FIGS. 12a-c;

14a-d: a partial cross section through a forming tool in various functional positions for steel strip cutting.

1 shows a first shell in the form of a cover shell 1. The cover shell 1 has a convexly outwardly arched pot-shaped middle part 3, the peripheral wall 29 of which merges into a retaining edge 4. The reduction collar 5 is located stepwise between the cup-shaped central part 3 and the retaining edge 4. The circumferential wall 29 is provided with a ribbed structure 30, which also protrudes on the inside 29a (see FIG. 4).

The retaining edge 4 is provided with a fastening means 47 in the form of a total of four threads 7a, 7b, 7c, 7d whose contours are formed both on the inside 6a (see FIG. 3) and on the outside 6b of the retaining edge 4 , By means of the threads 7a, 7b, 7c, 7d, for example, a second shell (see FIG. 7) which is designed as a base shell 2 can be fastened to the cover shell 1. The retaining edge 4 is also surrounded to the outside with a circumferential punching edge 49. This has a larger diameter than the cover shell 1, since this is dissolved out during manufacture, for example, with a holding and punching device 43 described in more detail from a sheet 23, wherein the holding and Stanzvor¬ direction 43 surrounds the cover shell 1 like a sleeve ,

In the side view of Figure 2, in particular, the course of Ge¬ windings 7a, 7b, 7d can be seen. The thread 7c is not visible in this view, since it is located on the back of the cover shell 1. The four threads 7a, 7b, 7c, 7d project outward and are delimited from one another by thread teeth 17a, 17b, 17c, 17d. The thread teeth 17a, 17b, 17c, 17d protrude inwardly on the inner side 6a (see FIG. 3) of the retaining edge 4 and form a running surface for complementary elements of the base shell 2. The elements can be used, for example, as holding wings 11a, 11b , 11c, 11d be formed according to Figure 5.

On the inlet side 31 of each thread 7a, 7b, 7c, 7d there is in each case a threaded inlet 48, which widens in the manner of a funnel in the direction of the inlet side 31 in order to facilitate reception of, for example, a retaining leaf 11a, 11b, 11c To allow 11d. In addition, the thread teeth 17a, 17b, 17c, 17d lying in the direction of rotation are correspondingly rounded on the inlet side 31.

All threads 7a, 7b, 7c, 7d run at an acute angle of less than 45 ° against the Reduzierbund 5. This area represents a clamping area 32, in which, for example, holding wings 11a, 11b, 11c, 11d are fixed with their front edge 12 (see FIGS. 7 to 10) in a combined state of lid and bottom pan 1, 2 ¬ the. FIG. 3 shows, in a cross section running through the center of the round cover 1, the course and the dimensioning of the threads 7a, 7b, 7d and the arrangement of the seal 8 formed as a sealing cone 8a.

The inner diameter 18 of the retaining edge 4 is defined by the clearance between two opposing thread teeth 17a, 17b, 17c, 17d. In FIG. 3, the inner diameter 18 is determined by the distance between the thread teeth 17b, 17d. The clear diameter within two opposite thread turns 7a, 7b, 7c, 7d is designated as the nominal diameter 15 of the retaining edge 4. In the figure 3, the nominal diameter 15 can be seen for example between the threads 7b, 7d. The nominal diameter 15 is always greater than the inner diameter 18.

Between the reducing collar 5 and the peripheral wall 29 of the cup-shaped middle part 3, the sealing cone 8a projecting in the direction of the underside 9 is visible, which runs closed around the cup-shaped central part 3. In the assembled state of the cover shell 1 and a bottom shell 2, the sealing cone 8a abuts from the inside against an opening edge 10 (FIGS. 7, 9) or the top section 34a (FIG. 9) of the cup wall 33 of the bottom shell 2, thereby producing a seal.

FIG. 4 shows, in an enlarged view, the area around the holder 4 in accordance with the sectional plane in FIG. 3. The thread 7a shown in this view has a profile that is open to the inside 6a and otherwise largely rectangular.

The reducing collar 5 runs horizontally and is thus essentially perpendicular to the upper section 34a of the cup wall 33 (see FIG. Between the reducing collar 5 and the peripheral wall 29 there is the sealing cone 8a, which projects beyond the clamping region 32 in the embodiment shown.

FIG. 5 shows a cover shell 1 without circumferential sealing cone 8a. This embodiment is provided for bottom shells 2, the opening edge 10 is to be closed with a sealing film. A sealing cone 8a, which in the assembled state of the cover shell 1 and the bottom shell 2 engages under the opening edge 10 of the bottom shell 2 (see FIG. 7), would push into the sealing film stretched over the opening edge 10 and is therefore suitable for such an embodiment form unsuitable.

Moreover, the embodiment of the cover shell 1 shown in FIG. 5 has a total of six threads 7a, 7b, 7c, 7d, 7e, 7f, which are distributed uniformly on the inside 6a (see FIG. 3). Such a cover shell 1 can also be screwed onto a bottom shell 2, not shown, with six retaining wings 11a, 11b, 11c, 11d.

FIG. 6 shows a further embodiment of the cover shell 1 with a cylindrical circumferential wall 29 perpendicular to the reducing collar 5. For reasons of better illustration, the cup-shaped central part 3 was shown without a central cover. On the inner side 29a of the circumferential wall 29, a toothing is arranged as a corrugated structure 30. The corrugated structure 30 does not extend through the peripheral wall 29. The outer side 29b of the peripheral wall 29 has rather a smooth surface. Due to the corrugated structure 30 aligned in the axial direction of the cover shell 1, it is possible to record torques acting on the cover shell 1 in circumferential direction over the corrugated structure 30 and a complementary formed forming tool 20 during the production process. FIG. 7 shows a bottom shell 2 as a second shell, with a slightly conically opened but substantially cylindrical baffle 33, which merges into an opening edge 10 in its upper section 34a. The lower section 34b of the cup wall 33 merges into a more conically tapered base region 35. On the underside, the bottom shell 2 is closed on one side with a bottom plate 36.

The opening edge 10 of the second shell has a fastening means 47 in the form of a total of four equally outwardly projecting retaining wings 11a, 11b, 11c, 11d. These retaining vanes 11a, 11b, 11c, 11d can be engaged in correspondingly formed threads 7a, 7b, 7c, 7d, 7e, 7f, as shown in FIGS. 1 to 6, and by a rotational movement between the shell 1 and the shell denschale 2 in the threads 7a, 7b, 7c, 7d, 7e, 7f fixed. The fixing takes place on the part of the holding wing 11a, 11b, 11c, 11d in the case of the usually used right-hand threads at the front edge 12 thereof.

The retaining wings 11a, 11b, 11c, 11d are located in a plane to one another and close up with the opening edge 10 plan.

The distance from the outer edge 14 of a retaining wing 11 b to the outer edge 14 of the opposite retaining wing 11 d is referred to as a circle diameter 16. The full circle diameter 16 is slightly smaller than the nominal diameter 15 of the cover shell 1. The outer diameter 19 of the opening edge 10 is measured outside the retaining wings 11a, 11b, 11c, 11d. So that the cover shell 1 can grip over the base shell 2, the outer diameter 19 is selected to be slightly smaller than the inner diameter 18 of the Halteran¬ of 4 (see Figure 3). The symmetrical distribution of the holding wings 11a, 11b, 11c, 11d can also be seen from the plan view according to FIG. In this view, the symmetrical configuration of each holding wing 11a, 11b, 11c, 11d is clear. Starting from a rounded outer edge 14 adapted to the curvature of the opening edge 10, the leading edge 12 and the trailing edge 13 of each retaining wing 11a, 11b, 11c, 11d extend at the same angle in the direction of the opening edge 10.

FIG. 9 shows a side view of the bottom shell 2. On the bottom plate 36, a conically opening base region 35 engages, which merges into the essentially cylindrical cup wall 33, which opens only slightly conically. In the upper section 34a of the cup wall 33, the latter passes into a counter-conical wall which in turn closes with the opening edge 10 or the holding wings 11a, 11b, 11c, 11d arranged thereon. The retaining wings 11a, 11b, 11c, 11d have the same material thickness as the opening edge 10. In addition, it can be seen that the retaining wings 11a, 11b, 11c, 11d lie in a horizontal plane with the opening edge 10. However, it is also possible to form the retaining wings 11 a, 11 b, 11 c, 11 d with a material thickness which is greater than the opening edge 10. The retaining wings 11 a, 11 b, 11 c, 11 d can then also on their underside a ramp-like bevel, approximately at the thread pitch, have.

FIG. 10 shows a top view of a bottom shell 2 with four holding wings 11a, 11b, 11c, 11d projecting radially from the opening edge 10. However, the retaining wings 11a, 11b, 11c, 11d have an asymmetric shape in relation to the embodiment shown in FIGS. 8 and 9. In this case, the leading edge 12 rises steeply in the radial direction. The angle is about 45 to 60 degrees. The leading edge 12 closes a uniformly convex curved common outside and Trailing edge 13, 14, which passes directly te in the nearest Vorderkan¬ 12.

In the following Figures 11 to 14, the production of a first shell in the deep-drawing process with a thread as well as different embodiments of the inventive mold 20 will be described. The shell in the present case is a cover shell 1.

A molding tool 20 in three different functional positions with a film 23 already formed into a cover shell 1 shows in section in a cross section the FIGS. 11a to 11c.

In the figure 11a are an inner punch 39, a holding sleeve 21 and a threaded sleeve 22 in an initial position to each other. At the same time, the threaded sleeve 22 surrounds the holding sleeve 21 and the inner punch 39 from the outside, both of which are arranged non-rotatably in the forming tool 20. The threaded sleeve 22 is pivotally mounted about the retaining sleeve 21. In the threaded sleeve 22, a contour 25 for creating a thread 7a, 7b, 7c, 7d, 7e, 7f is formed, so that a heated film 23 has adapted according to the shape of the Formwerk¬ tool 20 and in particular contours 25 of the threaded sleeve 22 ,

With the aid of the multi-part molding tool 20, comprising the retaining sleeve 21 and the threaded sleeve 22, it is possible, in a first step Ver¬ according to the figure 11a first, the at least two thread turns 7a, 7b, 7c, 7d, 7e, 7f to form and then the De¬ cokelschale 1 free from the mold 20. This is done in accordance with Figure 11b by unscrewing the threaded sleeve 22 relative to the stationary holding sleeve 21 in the direction of movement 37. After unscrewing the threaded sleeve 22 is below the level of Stamped counter 41 depressed and is no longer engaged with the thread 7a.

During the shaping shown in FIG. 11a and during the unwinding according to FIG. 11b, the film 23 is fixed via a holding device 40 arranged concentrically around the forming tool 20. For this purpose, the holding device 40 comprises a stationary stamping counter 41 and a holding plate 42, which can be lowered in the direction of the stamping counter 41. For fixing the film 23, this is clamped between the stamping counter 41 and the holding plate 42.

A twisting of the lid shell 1 formed in the film 23 is prevented by the holding sleeve 21 in addition to the holding device 40. For this purpose, the holding sleeve 21 is provided in its wall section 28 with Halte¬ ribs 26, which are particularly well visible in Figure 13. The retaining ribs 26 are formed in the peripheral wall 29 of the cover shell 1 as a ribbed structure 30 and permit a positive force transmission.

In a last method step shown in FIG. 11c, the holding sleeve 21 is moved back together with the inner punch 39 in the axial direction and the lowerable holding plate 42 is raised, so that the foil 23 with the lid shell 1 pronounced therein is released from the forming tool 20 and can be removed. In weite¬ Ren, known in the art steps then the Deckel¬ shell 1 can be dissolved out of the film 23.

Various functional positions of a mold for cutting mold 20 are also shown in Figure 12 in a partial cross-section. In this case, the assembly comprising the centrally located inner punch 39, the retaining sleeve 21 and the therefore pivotable threaded sleeve largely identical to the mold 20 shown in FIG. 11.

However, the molding tool 20 is concentrically surrounded by a holding and punching device 43 with which the cover shell 1 can be punched directly on the molding tool 20 from the film 23.

The holding and punching device 43 comprises the knife sleeve 24 immediately adjacent to the threaded sleeve 22, the stripper plate 44 arranged around the knife sleeve 24 and the knife plate 45 located above the stripper plate 44. Both the stripper plate 44 and the knife plate 45 are vertically movable.

The shaping of the cover shell 1 in the film 23 takes place according to the position of the molding tool 20 in FIG. 12a. Here, the film is fixed by the lowered in the direction of the stripper plate 44 blade plate 45 by a clamping action. After fixing stripping and knife plate 44, 45 were lowered together, so that in the transition stripper plate 44 to the knife sleeve 24 forms a step in the film 23 aus¬.

In FIG. 12b, the threaded sleeve is spinded out in accordance with the direction of movement 37 and a thread 7a in the cover shell 1 is visible. Before unwinding, the knife sleeve 24 was moved upward, whereby the film 23 is sheared at its entire outer circumference on the blade plate 45. In this embodiment, the torque transmitted when unwinding onto the film resting loosely on the molding tool 20 is taken up solely by the corrugated structure 30 formed in the peripheral wall 29 and the retaining ribs 26 complementarily shaped in the retaining sleeve 21, thereby turning the film from the film 23 dissolved lid shell 1 during unwinding avoided. Finally, as shown in FIG. 12 c, the inner punch 39 is axially advanced relative to the fixed holding sleeve 21 and the holding and punching device 43 is opened. By advancing the inner punch 39, the cover shell 1 can be very easily removed from the mold 20. The knife sleeve 24 has moved back to a lowered position.

In the partial plan view of FIG. 13 on the forming tool 20, the holding ribs 26 arranged in the holding sleeve 21 can be seen, which allow holding the lid shell 1 which has already been completely released from the film 23, or a holding of the still connected with the film 23 Support standing lid shell 1. For this purpose, the holding ribs 26 are in their axial alignment perpendicular to the direction of movement 37 of the threaded sleeve 22. The holding ribs 26 are located in the oblique wall portion 28 of the holding sleeve 21. The holding ribs 26 are found after the manufacturing process as a corrugated structure 30 on the finished molded lid shell. 1 again.

The holding sleeve 21 is provided with a plurality of vent holes 27, through which air between the film 23 and mold 20 escape or can be removed.

FIG. 14 shows a further alternative concerning the holding and supporting device 43 arranged around the forming tool 20 in a cut-out cross-sectional view for carrying out the band steel cutting.

The central assembly of the molding tool 20 also represents the inner punch 39, the shank 21 and the threaded sleeve 22. The forming tool 20 is surrounded by the holding and supporting device 43, which has a stationary punching counter 41, a lowerable holding plate T / EP2005 / 008779

24

42 and a guided on the holding plate 42 strip steel knife 46 summarized.

In a first method step, according to FIG. 14 a, the film 23 is moved over the forming tool 20 and fixed around the forming tool 20, in which the holding plate 42 is lowered and thereby the film 23 resting on the stamping counterpart 41 is clamped.

Subsequently, as can be seen in FIG. 14 b, the threaded sleeve 22 is spindled in the direction of movement 37. In this procedure, the film 23 is held by both the retaining sleeve 21 and the Folienver¬ bund.

Another method step illustrated in FIG. 14 c comprises lowering the strip steel blade 46 onto the film 23, as a result of which the cover shell 1 is removed in a peripheral manner from the film 23. However, the belt steel knife 46 is formed on its underside at discrete intervals with recesses, so that the cover shell 1 remains connected to the film 23 via rest webs 38. These residual ridges 38 break out in a controlled manner in subsequent stacking processes.

After punching out the cover shell 1 from the film 23, the holding plate 42 is raised and the inner punch 39 moves together with the holding sleeve 21 down to a uniform level of Stanzge¬ genlage 41 and lowered threaded sleeve 22 (Figure 14d). In this position, the film 23 can be removed together with the cover shell 1 in a simple manner horizontally from the mold 20 and the holding and punching device 43. 08779

25

LIST OF REFERENCE NUMBERS

1 lid shell

2 bottom shell

3 pot-shaped middle part

4 retaining edge

5 reducing collar

6a inside retaining edge

6b outside retaining edge

7a, 7b, 7c, threads

7d, 7θ, 7f

8 seal

8a sealing cone

9 underside first shutter

10 opening second!

11a, 11b, 11c, 11d retaining wing second shell

12 leading edge retaining wing

13 rear edge retaining wing

14 outer edge retaining wing

15 nominal diameter retaining edge

16 full circle diameter holding wings 17a, 17b, 17c, 17d thread tooth

18 inner diameter retaining edge

19 outer diameter opening edge

20 mold

21 retaining sleeve

22 Swiveling threaded sleeve

23 foil

24 knife sleeve

25 contour thread

26 holding ribs

27 breather holes Wall section retaining sleeve

Peripheral wall cup-shaped central part a inside peripheral wall b outside peripheral wall

Corrugated structure peripheral wall

Inlet side thread

Clamping range thread

Cup wall Bottom cup a Upper section Cup wall b Lower section Cup wall

Base area Cup wall

baseplate

Direction of movement threaded sleeve residual webs

inside the temple

holder

Punching counter support

Lowerable retaining plate

Holding and punching device

stripper

blade plate

Strip steel knife

fastener

Open thread inlet

punching edge

Claims

claims

1. First shell, for example a lid shell (1), made of a deep-drawn plastic molded part with an inner cup-shaped middle part (3) and an outer retaining edge (4), characterized ge indicates

in that a fastening means (47) for producing a threaded connection is arranged on the first shell (1, 2), wherein the fastening means (47)

a between the retaining edge (4) and the cup-shaped central part (3) formed Reduzierbund (5) and

at least two threads (7a, 7b, 7c, 7d, 7e, 7f) arranged on the inside (6) of the holding edge (4) with the same pitch

comprising, wherein the Reduzierbund (5) the at least two Ge¬ windegänge (7a, 7b, 7c, 7d, 7e, 7f) bounded on one side and the at least two threads (7a, 7b, 7c, 7d, 7e, 7f) a of¬ have thread inlet (48).

2. First shell according to claim 1, characterized in that the threads (7a, 7b, 7c, 7d, 7e, 7f) are each arranged diametrically an¬.

3. First shell according to claim 1 or 2, characterized gekennzeich¬ net, that the threads (7a, 7b, 7c, 7d, 7e, 7f) have a Stei¬ supply of 5 ° to 30 °.

4. First shell according to one of claims 1 to 3, characterized ge indicates that the shell (1, 2) with a seal (8) aus¬ is permitted.

5. First shell according to claim 4, characterized in that the seal (8) is formed as a concentric circumferential sealing cone (8a) on the underside (9) between the cup-shaped central part (3) and the Reduzierbund (5).

Second shell, for example, a bottom shell (2), from a deep-drawn plastic molded part with a cup wall (33), where the cup wall (33) in its upper portion (34a) with ei¬ NEM circular opening edge (10) is formed and in its lower portion (34b) with a bottom plate (36) permanently closed ver¬, characterized

in that a fastening means (47) for producing a threaded connection is arranged on the second shell (1, 2), wherein the fastening means (47) comprises at least two rigid retaining wings (11a, 11b) radially projecting on the circular opening edge (10). 11 c, 11 d).

7. Second shell according to claim 6, characterized in that the retaining wings (11 a, 11 b, 11 c, 11 d) are each arranged diametrically ange¬.

8. Second shell according to claim 6 or 7, characterized gekennzeich¬ net, that the retaining wings (11 a, 11 b, 11 c, 11 d) have a radially extending to the second shell leading edge (12) and trailing edge (13), which connected to each other via a concentric with the second shell curved outer edge (14).

9. resealable container with a first shell, spielsweise a cover shell (1) according to one of claims 1 to 5, and a second shell attachable to the first shell, for example a bottom shell (2) according to one of claims 6 to 8,

in which the first shell (1, 2) has an inner cup-shaped middle part (3) and an outer retaining edge (4),

in which the second shell (1, 2) comprises a cup wall (33), wherein the cup wall (33) is formed in its upper section (34a) with a circular opening edge (10) and in its lower portion (34b) a bottom plate (36) is permanently closed and

in which, in the assembled state, the first shell (1, 2) acts on the second shell (1, 2) from the outside and projects with a retaining edge (4) the second shell (1, 2),

characterized,

a reduction collar (5) is formed on the first shell (1, 2) between the retaining edge (4) and the cup-shaped central part (3), and

in that the first and second shells (1, 2) can be screwed together by means of a threaded connection (47), wherein the threaded connection (47)

at the first shell (1, 2) on the Innensei¬ te (6) of the retaining edge (4) at least two Threads (7a, 7b, 7c, 7d, 7e, 7f) have the same pitch, which are each bounded on one side by the reducing collar (5) and have an open threaded inlet (48), and

on the second shell (1, 2) comprises at least two of the circular opening edge (10) radially projecting rigid retaining wings (11a, 11 b, 11c, 11d).

10. Container according to claim 9, characterized in that the number of retaining wings (11 a, 11 b, 11 c, 11 d) is less than or equal to the number of threads (7 a, 7 b, 7 c, 7 d, 7 e, 7 f).

11. Container according to claim 9 or 10, characterized in that the at least two threads (7a, 7b, 7c, 7d, 7e, 7f) in the circumferential direction have a greater width than the retaining wings (11a, 11b, 11c, 11d).

12. Container according to one of claims 9 to 11, characterized gekenn¬ characterized in that the first shell (1, 2) in the region of the Halteran¬ of (4) and between the opposite Gewindegän¬ gene (7a, 7b, 7c, 7d, 7e, 7f) has a nominal diameter (15) which is slightly larger than the full circle diameter (16) of the holding wings (11a, 11b, 11c, 11d).

13. Container according to one of claims 9 to 12, characterized gekenn¬ characterized in that the first shell (1, 2) in a region between thread teeth (17 a, 17 b) of the threads

(7a, 7b, 7c, 7d, 7e, 7f) has an inner diameter (18), which is slightly larger than the outer diameter (19) of the opening edge (10).

14. Deep-drawing method for producing a first shell (1, 2), spielsweise a cover shell (1) according to one of claims 1 to 5, using a mold (20) with a rotatably mounted holding sleeve (21) and one to the holding ¬ sleeve (21) pivotable in the circumferential direction Gewindehül¬ se (22), in which

- In a starting position of retaining sleeve (21) and Ge threaded sleeve (22) a film (23) on the Formwerk¬ tool (20) is driven,

- The film (23) for forming the shell (1, 2) in the mold (20) is introduced, clamped and ausge¬ formed,

- The threaded sleeve (22) is brought by spindling in an Endstel¬ ment and

- The shell (1, 2) is stripped from the retaining sleeve.

15. thermoforming method according to claim 14, wherein the shell (1, 2) during the unwinding of the holding sleeve (21) and / or of the film (23) is held.

16. deep drawing method according to claim 14 or 15, wherein the Scha¬ le (1, 2) is stripped off together with the film (23) of the holding sleeve (21).

17. deep-drawing method according to claim 14 or 15, wherein the Scha¬ le (1, 2) on the mold (20) after the unwinding of the threaded sleeve (22) from the film (23) is punched.

18. deep-drawing method according to claim 14, wherein the shell (1, 2) on the mold (20) before the unwinding of the Gewinde¬ sleeve (22) from the film (23) is punched.

19. deep drawing method according to claim 17 or 18, wherein the Scha¬ le (1, 2) is completely punched out of the film (23).

20. deep drawing method according to claim 17 or 18, wherein the Scha¬ le (1, 2) is partially punched out of the film (23) and Restste¬ GE (38) between the film (23) and the shell (1, 2) stay standing.

21. Forming tool (20) for carrying out the method according to ei¬ nem of claims 14 to 20 with a rotatably mounted holding sleeve (21) and to the holding sleeve (21) in the circumferential direction from a starting position in an end position spindelba¬ ren threaded sleeve ( 22), wherein in the threaded sleeve (22) Kontu ren (25) for forming at least two Gewindegän¬ gene (7a, 7b, 7c, 7d, 7e, 7f) are formed.

22. The mold according to claim 21, wherein an inner punch (39) is arranged centrally within the holding sleeve (21).

23. A mold according to claim 22, wherein the Innenstem¬ pel (39) and / or the retaining sleeve (21) in the axial direction ver¬ pushed.

24. Shaping tool according to one of claims 21 to 23, wherein the threaded sleeve (22) concentrically around the retaining sleeve (21) is arranged ange¬.

25. Forming tool according to one of claims 21 to 24, wherein the retaining sleeve (21) has an inclined wall portion (28), in which retaining ribs (26) are arranged.

26. The mold according to claim 25, wherein the holding ribs (26) are aligned in the axial or radial direction of the holding sleeve (21).

27. Forming tool according to one of claims 21 to 26, wherein a holding device (40) is arranged around the threaded sleeve (22).

28. The mold according to claim 27, wherein the Haltevorrich¬ device (40) comprises a fixed punching counterpart (41) and a ab¬ lowerable retaining plate (42).

29. Forming tool according to one of claims 21 to 26, in which circumferentially around the threaded sleeve (22) has a holding and Stanzvor¬ direction (43) is arranged.

30. A mold according to claim 29, wherein the holding and Stanz¬ device (43) comprises a stripper plate (44), a lowerable Mes¬ serplatte (45) and a threaded sleeve (22) concentrically um¬ giving fixed knife sleeve (24) , wherein the Ab¬ streifplatte (44) and the knife plate (45) are vertically movable.

31. A mold according to claim 30, wherein the knife sleeve (24) between the threaded sleeve (22) and the stripper plate (44) is arranged an¬.

32. Forming tool according to claim 29, wherein the holding and Stanz¬ device (43) comprises a fixed punching counterpart (41), a lowerable holding plate (42) and on the punching counterpart (41) can be lowered tubular steel knife (46).

33. Forming tool according to one of claims 21 to 32, wherein in the retaining sleeve (21) vent holes (27) are arranged.

34. Forming tool according to one of claims 21 to 33, wherein the threaded sleeve (22) travels between the initial and final position a travel path, which speaks ent speaking 10% to 25% of its circumference.