EP0147423B1 - Plastic closure - Google Patents

Abstract

The plastic closure which may be placed on solid or deformable containers or which may be an integral part of a container, has a lower portion (1) and a cover or cap (2). The cap (2) is integrally connected to the lower portion (1) by at least one securing band (3). The securing bands (3) are arranged within a plane (E) intersecting the plastic closure, i.e. the cap (2) and the lower portion (1) when the closure is closed. It is possible to make the closure with or without a hinge (5). The arrangement of the securing bands according to the disclosure generates a closing force. Such closures may be used for a plurality of different containers or be integral with a box.

Description

The present invention relates to a plastic closure for solid or deformable containers, which closure is an integral part of the container or can be placed thereon, with a lower part and a cap or a cover which is integrally connected to the lower part via at least one tensioning strap.

From CH-PS 619413 a plastic closure of the above type is known. The function of the tightening strap or the tightening straps is described as a retainer which, when it is opened, holds the cap in the open position. Such arrangements have long been known in the closure technology ik in various designs. The tensioning straps according to the above-mentioned patent lie in the closed position of the closure in a plane outside the closure. However, because the tensioning straps are tensioned in the closed position of the closure, they have a tendency to open the closure, and the closure should therefore always be provided with corresponding locking members opposite the tensioning straps, which counteract this effect.

Another known solution to counteract the unwanted opening effect of the straps is shown in the same patent. In this case, an integral film hinge is arranged on the lower part and cap in such a way that the axis of rotation is located further from the center of the closure outside of the latter.

• a) Beim Öffnungs- und Schliessvorgang resultieren erhebliche Kräfte, die enorme Anforderungen an das Filmscharnier stellen. Folglich lassen sich solche Verschlüsse nur aus hochwertigem, teurem Kunststoff realisieren, wie zum Beispiel aus Polypropylen.
• b) Die Anordnung des Filmscharniers relativ weit ausserhalb des eigentlichen Verschlusses erfordert erhebliche Anpassungen an die Verschliessmaschine einer Abfüllanlage. Nicht nur müssen die Greifer entsprechend formlich gestaltet werden, sondern auch die Zuführung des Verschlusses muss exakt positioniert erfolgen.
• c) Die Verschliesskraft der Spannbänder ist auch bei relativ entfernter Anordnung des Filmscharniers ausserhalb des Verschlusses nur gering.
• d) Das Erfordernis, ein Filmscharnier überhaupt haben zu müssen, führt zu einem zwingenden Bewegungsmechanismus, der äusserst einschränkend auf die geometrische Gestaltung von Unterteil und Kappe wirkt. Insbesondere Verschlüsse mit Aufbauten am Unterteil, wie zum Beispiel eine hochgezogene Ausgussöffnung, in die ein in der Kappe angeordneter Zentrierzapfen eingreifen soll, haben sich kaum bewerkstelligen. Auf jeden Fall erfolgt beim Schliess- beziehungsweise Öffnungsvorgang eine erhebliche Beanspruchung des Filmscharniers, und der gesamte Verschluss wird dabei ständig leicht deformiert. Insbesondere werden die Kanten des Zentrierzapfens und der Ausgusslippeverletzt, wodurch sowohl der Dichteffekt wie die Ausgusseigenschaften des Verschlusses leiden.

This solution has several disadvantages:

• a) The opening and closing process results in considerable forces that place enormous demands on the film hinge. As a result, such closures can only be made from high-quality, expensive plastic, such as polypropylene.
• b) The arrangement of the film hinge relatively far outside the actual closure requires considerable adjustments to the capping machine of a filling system. Not only must the grippers be designed appropriately, but the closure must also be fed precisely positioned.
• c) The closing force of the tensioning straps is only slight even when the film hinge is arranged relatively away from the closure.
• d) The requirement to have a film hinge at all leads to a mandatory movement mechanism that has an extremely restrictive effect on the geometric design of the lower part and cap. In particular, closures with structures on the lower part, such as, for example, a raised pouring opening, into which a centering pin arranged in the cap is to engage, have scarcely been able to be accomplished. In any case, there is considerable strain on the film hinge during the closing or opening process, and the entire closure is constantly slightly deformed in the process. In particular, the edges of the centering pin and the pouring lip are injured, as a result of which both the sealing effect and the pouring properties of the closure suffer.

The object of the invention is to provide a closure of the type described at the outset which eliminates the disadvantages mentioned.

This object is achieved by a closure according to the preamble of the patent claim, which is characterized in that in the closed state of the closure the tensioned strap or the tensioned straps run or run in a plane that intersects the plastic closure.

With this arrangement, the resulting force of the tensioning straps acts as the closing force of the closure, even when the closure is closed.

In a preferred embodiment of the closure, the strap level can run parallel to a perpendicular to the parting plane between the lower part and the cap. This has the effect that the resulting force in the closed position is also introduced vertically onto the parting plane.

Further embodiments and their advantages are evident from the claims and the description below. Various design variants are shown in the drawing and explained in the description.

• Figur 1 einen zylindrischen Verschluss in Aufsicht, und
• Figur 2 denselben Verschluss in Seitenansicht,
• Figur 3 stellt einen gleichen Verschluss zum Aufsatz auf ein Behältnis mit prismatischer Form dar, und
• Figur 4 zeigt wiederum den Verschluss nach Figur 3 in Seitenansicht,
• Figur 5 verdeutlicht die geneigte Lage von Spannbändern an einem zylindrischen Verschluss,
• Figur 6 ist eine Aufsicht auf eine mit dem erfindungsgemässen Verschluss ausgestaltete Dose, und
• Figur 7 zeigt den Schnitt durch die Dose nach Figur 6 entlang der Linie A-A, während
• Figur 7a einen Detailausschnitt der Figur 7 zeigt. In den
• Figuren 8a-d werden vier Öffnungspositionen eines scharnierlosen Verschlusses dargestellt.

It shows:

• Figure 1 is a cylindrical closure in supervision, and
• FIG. 2 shows the same closure in a side view,
• FIG. 3 shows an identical closure for attachment to a container with a prismatic shape, and
• FIG. 4 again shows the closure according to FIG. 3 in a side view,
• FIG. 5 illustrates the inclined position of tensioning straps on a cylindrical closure,
• FIG. 6 is a top view of a can designed with the closure according to the invention, and
• Figure 7 shows the section through the can of Figure 6 along the line AA, while
• Figure 7a shows a detail of Figure 7. In the
• FIGS. 8a-d show four opening positions of a hinge-free closure.

The closure according to the invention always consists of a lower part 1 and a cap or lid 2. Depending on the use of the closure, the lower part 1 is placed on a solid or deformable container, not shown in the drawing, or represents the lower part of the container itself.

In Figures 1 -5 and 8a to d closures for attachment to solid or deformable containers are shown. In the closed state of the closure, the lower part 1 and the cap 2 are in direct contact with one another. The contact surface lies in the so-called parting plane, which is designated T in the drawing. The lower part 1 and the cap or lid 2 are integrally connected to one another via at least one tension band 3. The tensioning straps 3 are from the lower part 1 or from the cap 2 via sprues 4 slightly distant. The straps 3 run in a plane E. The plane E intersects the closure parallel to its axis of rotation a. In the variant according to FIGS. 1 and 2, the lower part 1 and the cap 2 are connected to one another via a film hinge 5.

The pivot axis of the film hinge 5 is on the one hand in the parting plane T and on the other hand parallel to the plane E in which the tensioning straps 3 are located.

In the closed position of the closure, the tensioning straps 3 are tensioned, as a result of which there is a resultant force which lies within the outline of the closure of plane E and maintains a closing pressure between the lower part 1 and the cap 2. If the closure is intended for use on a container with a gas content, the closing pressure should be as large as possible.

This can be adjusted accordingly by dimensioning and positioning the straps. Material-related physical properties such as modulus of elasticity and strength must not be neglected. An optimal solution can often only be found empirically. The variable sizes in their dimensioning are the width and the thickness of the tensioning straps 3 and the distance of the plane E in which the tensioning straps 3 lie to the axis of rotation a of the closure.

Nothing is explained in this description of the possible locking members that can be combined with the closure according to the invention.

Of course, the closure according to the invention can be combined with any type of known locking element, for example also with a childproof locking element.

The closure according to the invention can be attached to any design of the lower part and the cap if appropriately adapted. Figures 3 and 4 show a lower part 1 and a congruent cap 2 with a twelve-sided plan.

The tensioning straps 3, which in turn are attached to the cap 2 or the lower part 1 via sprues 4, are in turn in a plane E which cuts the closure. The hinge 5 should run approximately in the parallel side surface 6 closest to the plane E.

In FIGS. 1-4, the plane E, in which the tensioning straps 3 lie, runs parallel to a vertical to the parting plane T, which in the present case is identical to the axis of rotation a. However, this is by no means mandatory, as the embodiment according to FIG. 5 shows. Here, too, the straps 3 run in a plane E, which in turn cuts the closure, but this time the plane E is inclined to the vertical v to the parting plane T. In the example shown in FIG. 5, the sprues 4 are also arranged asymmetrically to the parting plane T, in contrast to the examples described above. The inclined straps 3 cause two things. On the one hand, the resulting pressure force between the lower part 1 and the cap 2 acts increasingly towards the center of the closure, on the other hand, this arrangement influences a slight change in the closing movement, as a result of which a centering pin which may be arranged in the cap provides a more precise introduction into a spout to be sealed by the centering pin receives.

This applies in particular if the closure is designed without a hinge, as will be described with reference to FIGS. 8a-8d.

Due to the asymmetrical arrangement of the sprues 4 on the lower part and on the cap 2, the position of the maximum expansion of the tensioning straps 3 can be shifted accordingly. From the position of maximum expansion 3, the cap folds in the direction of the closed or open position. The desired opening position of the cap 2, in which the tensioning straps 3 are relaxed, can be desired differently depending on the type of closure, the shape of the spout or the type of container to be closed.

FIG. 6 shows a can which is designed with the closure according to the invention. The can and thus also the lower part 1 and the cap 2 have an approximately rectangular plan. The lower part 1 and cap 2 are connected to one another here via three tensioning straps 3 arranged on the same side surface. Instead of the three tightening straps shown here, the closure can of course also be formed from a single, somewhat wider tightening strap. Here again, the tensioning straps 3 are arranged inclined to a vertical v on the parting plane T. For this purpose, the straps 3 are in niche-like recesses 7 which are inclined to the longitudinal side 8 of the can.

FIG. 7 shows a section along line A-A according to FIG. 6. The conditions in the area of the niche-like recess 7 are illustrated in detail in FIG. 7a. The arrangement of tensioning straps 3 in niche-like recesses 7 can of course also be realized with other forms of closure, such as those in the figures described above. The arrangement of the straps 3 in niche-like recesses 7 has the advantage that no parts of the closure protrude beyond the contour of the lower part or the cap. This is particularly advantageous if the closure is mechanically placed on a container, since the closure then no longer has to be aligned with a gripper, in accordance with the above parts.

In Figures 8a - a hinge-less closure is shown in different openings. Again, this is a closure with a cylindrical lower part 1 and cover 2 with the same cover. The sprues 4 for the tensioning straps 3 are in turn asymmetrical to the parting plane T. Of course, the level E in which the tensioning straps 3 lie also intersects the closure here.

The special feature of the present closure is that it has no hinge, so that the cap 2 and the lower part 1 only on the instep bands 3 are interconnected. In the closed position according to FIG. 8a, the closing forces which are exerted by the tensioning straps 3 behave in the same way as in the variants described above. The closing force lies within the plane E and is represented by an arrow F indices I.

Figure 8b shows the same closure in a slightly open intermediate position. The tensioning straps 3 are now somewhat more stretched and now produce a somewhat increased resulting force F 2. The resulting force F 2 still runs in the plane of the tensioning straps, which is however now inclined in accordance with the degree of opening of the cap 2. Consequently, the resulting force F 2 can be broken down into a component FS, which tends to close the cap 2, and into a component FZ, which tends to pull the cap 2 towards the center or the axis of rotation a. In this position it can already be seen that the lower part 1 has a structure 9 which is offset inward about the wall thickness of the cap 2 concentrically with the axis of rotation a. The structure 9 runs conically to a central pouring opening 10.

In the position according to FIG. 8b, the fictitious axis of rotation is parallel to plane E and runs exactly through the point of contact between cap 2 and lower part 1.

As the opening angle of the cap 2 increases, the component FS decreases and the component FZ increases accordingly. This continues until the force component FZ overcomes the static friction between the lower part 1 and the cap 2, whereupon the cap 2 abruptly abuts against the set-back structure 9. The cap 2 is completely opened, as shown in FIG. 8c, and the tensioning straps 3 relax largely, but not completely, so that a small resulting force remains which holds the cap 2 in the open position according to FIG. 8c. If the structure 9 has only a low overall height, as shown in FIG. 8c, the tensioning straps 3 could pull the cap 2 onto the structure 9 and thus make it much more difficult to close the cap 2 again. In this case, a stop 11 is molded onto the structure 9, which is located in the area between the two sprues 2 of the lower part 1. The sequence of movements when opening and in particular when closing the closure is optimized in that the transition 12 from the lower part 1 to the structure 9 is rounded. If the structure 9 is relatively low, as shown in FIG. 8c, the rounded transition 12 can run directly from the parting plane T to the stop 11.

In FIG. 8d, the closure according to the invention is finally shown in the spray position. The parting plane T here is also the parting plane of the injection mold. The tensioning straps 3 are injection molded so that they have a greater length than the distance between the two corresponding sprues 4, which corresponds to the injection mold.

The hinge-free design is of course not only possible with rounded closures, but in principle with any design of the closure. In the embodiment according to FIGS. 6 and 7, one would then only have to speak of a line of contact instead of a point of contact. If the closure has an odd number of tensioning straps, as can be seen in FIG. 6, then if the structure 9 is too low, an even number of stops 11 would have to be provided. In the case of a can, the structure 9 would, for example, only correspond to an inwardly offset edge. As is known from many boxes.

Claims (10)

1. Syntheticplasticsclosureforsolidordeform- able containers which is an integral component of the container or is settable thereupon, having an under part (1) and a cap or lid (2) integrally connected with the under part through at least one tie strap (3), characterised in that when the closure is in the closed condition the tensioned tie strap (3) or the tensioned tie straps (3) extends or extend in a plane (E) which intersects the synthetic plastics closure.

2. Synthetic plastics closure according to Claim 1, characterised in that the plane (E) extends perpendicularly of the plane (T) of separation between under part (1) and cap (2).

3. Synthetic plastics closure according to Claim 1, characterised in that the plane (E) extends at an inclination to the plane (T) of separation between under part (1) and cap (2).

4. Synthetic plastics closure according to Claim 1, characterised in that the under part (1) and the cap (2) are additionally connected with one another through a hinge (5) the axis of which forms at least approximately a tangent to the body of the closure and lies parallel to the plane (E) in which the tie strap (3) or tie straps (3) extends or extend.

5. Synthetic plastics closure according to Claim 1, characterised in that under part (1 ) and cap or lid (2) are hingelessly connected with one another through the tie strap or straps (3).

6. Synthetic plastics closure according to Claim 5, characterised in that the under part (1) of the closure comprises an added part (9) elevated in relation to the plane (T) of separation between cap (2) and under part (1 ), which part (9) is narrowed approximately by the wall thickness of the cap (2).

7. Synthetic plastics closure according to Claim 6, characterised in that an imaginary axis, in the closed position, extends through the point in the plane (T) of separation between under part (1) and cap or lid (2) which is placed closest to the plane (E) in which the tie strap or straps (3) lies or lie, while the point of contact travels on a line along the added part (9) during the opening and closing operation.

8. Synthetic plastics closure according to Claim 5, with polygonal circumferential line, characterised in that the tie strap or straps (3) lies or lie in a plane (E) which extends parallel to the nearest edge (6) of the circumferential line.

9. Synthetic pfastics closure according to Claim 6, characterised in that the elevated, narrowed under part (1) comprises, in the region between two tie straps (3), a rounded transition (12) from the plane (T) of separation to the added part (9).

10. Synthetic plastics closure according to Claim 5, characterised in that a stop (11) rising above the plane (T) of separation between cap and under part is arranged on the under part (1) of the closure, in teh region between two tie straps (3).

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