DE3439212A1 - Screw closure with originality safeguard made of plastic and injection mould for producing caps - Google Patents

Abstract

The screw cap (6) is connected at its lower end via a tear line (16) to a locking ring (18). The tear line (16) is formed by a connecting skin (20) and contains at least one moulded-in driving tooth (22). The latter has a steep flank (24) which is effective in the screwing-on direction (A). A shallow flank (26) acts in the unscrewing direction (B). This design permits simple production. Furthermore, the screw closure provides particular security against destruction during handling. The screw closure ensures a good originality function while still permitting simple first-time opening of the screw cap. <IMAGE>

Description

Screw cap with tamper-evident plastic

and injection molding tools for producing caps. The invention relates to a screw cap with a tamper-evident seal made of plastic according to the generic term of claim 1; and an injection molding tool for producing caps according to Preamble of claim 6.

Screw closures of the type mentioned are known several times, for example from DE-OS 27 04 461. With this screw cap, the Connection between the screw cap and the locking ring along the tear line formed by radial webs, which the connection between the lower edge of the Make the screw cap and the upper edge of the locking ring. As driving elements axially protruding cams are arranged on the upper edge of the locking ring, which are upstream of the connecting webs.

On the inside of the locking ring is a locking element Composed locking bead arranged, which can engage behind a container bead.

This screw cap has various disadvantages.

So is the connection between the screw cap and the locking ring relatively complicated and requires a complicated injection molding tool for production. The screw cap also has the disadvantage that the connecting webs between the screw cap and the locking ring when handling the screw cap can easily be destroyed during sorting and machine placement.

This has the consequence that the tamper-evident already from In the beginning is at least partially destroyed. On the other hand, arise through additional Control and re-sorting work high costs when processing this screw cap. There is also the risk that the locking ring will become jammed if the screw cap is tilted can slide with its locking bead on one side over the container bead and thus easily is removable from the container, which is undesirable.

Injection molding tools for the production of caps of the types mentioned at the beginning Kind, in particular for the production of such screw closures, are for example from DE-OS 29 43 717 known. The screw cap is in an external molded part produced, which is retractable to the opening of the mold.

The locking ring is formed in a fixed base plate. The inner shape of the screw cap is formed by a core, which is in the axial Direction is movable.

This injection molding tool is very simple, but has crucial features Disadvantages on. In order to form the produced cap, the mold must first go through Retraction of the outer molded part are opened. Then the core must be withdrawn the screw cap must move radially outwards so that the radial Profile parts engaging in the core can come freely. After all, he has to screw cap still hanging with the circlip on the lower part of the tool of the ejector advancing through the core can be released from the lower mold. Again, this is only possible by radial displacement of the locking ring from the Form recess possible. Since the displacement of the shape takes place radially inward, what a compression of the screw cap results in the molding Trouble. This leads in particular to the fact that the one provided along the tear line Connection skin can tear off during molding. If this is to be avoided, it would have to the connection dung skin can be made particularly strong, but what again the forming and tearing off of the locking ring when opening the screw cap would make it difficult. Furthermore, this device can only be used for simple profiling be formed between the screw cap and locking ring.

The object of the invention is to provide a screw cap and an injection molding tool of the type mentioned in such a way that they do not have the disadvantages mentioned exhibit.

In the case of a screw cap, the task at hand is the one at the beginning mentioned type solved by the characterizing features of claim 1. At a Injection molding tool of the type mentioned at the outset accomplishes the task set the characterizing features of claim 6 solved.

The fact that in the screw cap, the tear line through a axial connecting skin formed between the screw cap and the locking ring is, the locking ring does not protrude radially, so that this alone creates a risk the separation of the locking ring when the screw cap is mechanically processed is prevented. This risk is compounded by the continuous connecting skin reduced.

The driving tooth integrated in the tear line also prevents it Destruction of the connecting skin when the screw cap is put on. Still will the flat flank ensures that the locking ring is securely separated along the tear line when unscrewing the screw cap, i.e. when opening the screw cap.

Advantageous designs of the screw cap are in the claims 2 to 5 described.

The security against destroying the screw cap along the tear line on the one hand when mechanical placement and the safe tearing off of the locking ring along the tear line when opening the screw cap for the first time is through a training of the screw cap according to claim 2 promoted.

The steep flank of the driver tooth can form an angle to the longitudinal axis exhibit. However, an embodiment according to claim 3 is particularly advantageous. There are also various possibilities with regard to the design of the flat flank.

However, an embodiment according to claim 4 is particularly useful.

A design of the screw cap is particularly expedient according to claim 5. By the axially spaced locking beads ensures that even if the screw cap is tilted during handling, especially when opening for the first time, even then a secure hold of the locking ring on the container is guaranteed if the Screw closure a locking bead should have slid over the container bead. Further sliding is then prevented by the second locking bead.

The new injection molding tool is characterized by a particularly simple one Structure and also enables the production of caps, in particular screw caps of the present type, with drawn-in profile parts. By the side Collet chuck-like moldings are ensured when the mold is opened that too these side moldings are opened and release the molding. Leave with it Complicated laterally drawn-in profile parts on the molding can also be found in a simple manner produce and it can also be gently ejected such moldings. A In particular, such an injection molding tool enables screw closures of the above gently manufacture mentioned type.

Advantageous configurations of the injection molding tool are shown in Claims 7 to 11 described.

The collet-like molded parts can be arranged in any way be and be operated. For example, there is also an arrangement of the collet chuck-like Molded parts in the retractable outer molded part possible. Appropriately they are Collet-like molded parts, however, in the fixed molded part of the injection molding tool arranged. An arrangement and design according to the claim are particularly advantageous 7th

A simple design and arrangement of the centering ring or the Collet-like molded parts describes claim 8. Particularly simple and advantageous however, is an embodiment according to claim 9. The collet-like molded parts can either be preloaded in the closed position or according to claim 10 in the open position be. The latter is usually more beneficial.

Claim 11 describes an expedient embodiment of the injection molding tool, the ejection sleeve either assisting or bringing about the opening of the collet can. The latter especially when the collet is preloaded in the closed position is.

Embodiments of the subject matter of the invention are given below described in more detail with reference to the drawings, in which: FIG. 1 shows a screw cap in side view and cut on one side; Figure 2 the neck of a container for Attachment of a screw cap according to Figure 1; Figure 3 shows the detail of a Circlip with two locking beads in view of the inside; Figure 4 a first injection molding tool with open mold in vertical section; FIG. 5 the injection molding tool FIG. 4 in section V-V of FIG. 4; FIG. 6 the injection molding tool of the figure 4 with closed shape; FIG. 7 a further injection molding tool with an open Shape in vertical section; FIG. 8 the injection molding tool of FIG. 7 in section VIII-VIII of Figure 7; and FIG. 9 shows the injection molding tool of FIG. 7 with the closed Shape.

Figure 1 shows a screw cap 2, as it is for a container 4 according to Figure 2 is suitable. The screw cap contains a screw cap 6, which has an internal thread 8 and on the outside ribs 10 for better gripping of the Has screw cap 6. The screw cap can be completely customized be designed accordingly and have, for example, a sealing lip 12, or be equipped with pouring devices and the like. At the lower edge 14 of the screw cap 6, a locking ring 18 is connected via a tear line 16.

The tear line 16 is formed by a connecting skin 20, which the screw cap 6 connects to the locking ring 18. In this tear line 16 is a driver tooth 22 is formed, which has a steep flank effective in the screwing-on direction A. 24 and a flat flank 26 effective in unscrewing direction B. The steep flank 24 is preferably parallel to the axis 28 of the screw cap 6. The flat flank 26 on the other hand, forms an angle Ci with the circumferential line, which is preferably 4 to 100, is expediently 70. The screw cap 2 at least two driver teeth 22 evenly distributed around the circumference, of which in Figure 1, however, only one is shown.

The locking ring 18 contains a locking bead on its inside 30, which is preferably divided into locking bead elements 32 on the circumference of the locking ring 18 and spaced from each other. The locking bead 30 with its locking bead elements When the screw cap 2 is screwed on, 32 engages behind the container 4 a container bead 34 and holds the locking ring 18 there.

The latter also when the screw cap 2 is opened, i. E. the screw cap 6 is unscrewed. Then the locking ring 18 remains by means of the locking bead 30 hang on the container bead 34 and the screw cap 6 is over the tear line 16 with destruction of the connecting skin 20 from the securing ring 18 separated. The driver tooth 22 supports the cutting process by means of the flat flank 26th

Figure 2 shows a further embodiment of the locking ring, wherein at an axial distance from the first latching bead 30, a second latching bead 36 made of latching bead elements 38 is arranged. This is considered to be an additional safeguard against the locking ring slipping off 18 from container 4.

Figures 4 to 6 show a first injection molding tool for production of caps in general, which in particular also for the production of caps according to Figure 1 is suitable.

The injection molding tool contains a machine frame 42 on the one fixed molded part 44 is arranged, to which a movable outer molded part 46 assigned. In the latter, the mold engages in the closed state (Figure 6) a core 48 which is attached to a core holder 50 which in turn is attached to the Machine frame 42 is held. Coaxial with the core 48 and core holder 50 is in this an ejector 52 mounted so as to be axially displaceable and fastened to an ejector plate 54 is. The latter interacts via bolts 56 with a further plate 58, which an ejection sleeve coaxial with the core 48 and core holder 50 and axially displaceable wearing. In the embodiment of Figures 4 to 6 are collet-like Molded parts 62 are present, which are arranged coaxially to the ejection sleeve 60 and in the axial direction Direction are shiftable.

Conical outer surfaces 64 of the collet-like molded parts 62 act with a centering ring 66, which is arranged in the fixed molded part 44 is. The collet-like molded parts 62 are biased outward and are held in its centered position by the movable outer molded part 46 when this is in the closed position shown in FIG. The collet-like Mold parts 62 have ribs 68 which, together with the core 48, to the mold cavity Production of the connecting skin 20 between the screw cap 6 and the locking ring 18 form. The collet-like molded parts 62 are in the fixed molded part 44 freely movable. To open the collet-like molded parts 62 must first the movable outer molded part 62 can be retracted (FIG. 4). When pushing forward the ejection plate 54 is pushed forward at the same time the ejection sleeve 60, which over a conical shoulder 70 on a conical shoulder 72 on the collet-like Attacks molded parts 62 and this also pushes forward until a rear flange in the recess 74 of the fixed molded part 44 is present.

The collet-like molded parts 62 open because of their Spring preload to the outside and release the screw cap 2 produced. This opening movement of the collet-like molded parts 62 can be achieved by the interaction the conical paragraphs 70, 72 are still supported.

Due to the synchronous movement of the ejector 52 and the ejector sleeve 60, the cap or screw cap 2 produced in this way is gently removed from the core 48 removed.

FIGS. 7 to 9 show a further injection molding tool that is analogous the injection molding tool of Figures 4 to 6 is constructed so that the same parts are provided with the same reference numerals and reference is made to the statements there will. In contrast to the injection molding tool of FIGS. 4 to 6, the Injection molding tool of FIGS. 7 to 9, collet-like molded parts 76 are used, which are fixed in the fixed mold part 44, i.e. not axially displaceable are. The centering ring used to close the collet-like molded part 76 78 is arranged on the movable outer molded part 46 in this exemplary embodiment.

When the mold is closed (FIG. 9), the centering ring 78 presses the collet-like Molded parts 76 against the core 48. When the movable outer molded part is retracted 46, the centering ring 78 releases the collet-like molded parts 76 again (FIG 7). In this embodiment, the collet-like molded parts 76 can also be biased against the core 48, the opening movement then being exclusive by the extension of the ejection sleeve 60 and the interaction of the conical shoulders 70, 72 of the ejection sleeve 60 and the collet-like molded parts 76 can take place.

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Claims (11)

Patent claims t) screw cap with tamper-evident security Plastic, with a screw cap at the bottom over a tear line with a Circlip is connected, the at least one container bead on its inside Has engaging locking bead and the effective in the unscrewing direction Driving elements is connected to the screw cap, characterized in that that the tear line (16) is formed by an axial connecting skin (20) and Contains at least one driver tooth (22) molded in, one in the screwing-on direction (A) effective steep flank (24) and a flat flank effective in unscrewing direction (B) (26). 2. Screw closure according to claim 1, characterized in that the tear line (16) at least two driver teeth evenly distributed around the circumference (22). 3. Screw closure according to claim 1, characterized in that the steep flank (24) at least approximately parallel to the longitudinal axis (28) of the screw cap (2) is. 4. Screw closure according to claim 1, characterized in that the flat flank (26) forms an angle CC of 4 to 100 with the circumferential line. 5. Screw closure according to claim 1, characterized in that the locking ring (18) on its inside at least two with an axial distance having mutually arranged locking beads (30, 36), which are preferably each made of formed on the circumference of the locking ring (18) distributed locking bead elements (32, 38) are. 6. Injection molding tool for the production of caps with retracted Profile parts, with an outer molded part that can be retracted to the opening of the mold and a core as well as lateral moldings for the production of the drawn-in profile part, furthermore with an ejector, characterized in that the lateral molded parts (62, 76) are designed like collets and when the mold is closed by means of a Centering ring (6, 78) can be held together. 7. Injection molding tool according to claim 6, characterized in that the collet-like shaped parts (62, 76) coaxially over an ejector sleeve (60) are arranged, the ejection sleeve (60) in turn being coaxial and displaceable arranged over a core holder (50) and movable synchronously with the ejector (52) is. 8. Injection molding tool according to claim 6, characterized in that the centering ring (66) is stationary and the collet-like molded parts (62) are axial are arranged displaceably, the whole preferably in such a way that the collet-like Molded parts (62) closed by means of these when the outer molded part (46) is closed are durable and with the outer molded part (46) open by means of the ejector (52) are axially displaceable in the open position. 9. Injection molding tool according to claim 6, characterized in that the collet-like molded parts (76) are stationary and the centering ring (78) is axial are arranged displaceably, the centering ring (78) preferably on the movable Outer molding (46) is arranged. 10. Injection molding tool according to claim 6, characterized in that the collet-like molded parts (62, 76) are biased in the open position. 11. Injection molding tool according to claim 7, characterized in that the collet-like molded parts (62, 76) have a conical shoulder on the inside (72), in the closed position of the mold with a counter-conical shoulder (70) of the ejection sleeve (60) cooperates.