MXPA99007465A - Plastic screw top - Google Patents

Abstract

The invention relates to a plastic screw top for bottles, consisting of a cap with a substantially cylindrical casing (1), with an internal screw thread (8) for screwing onto the external screw thread (11) of a bottle neck (10), and with a substantially disk-like top plate, (2) and a substantially cylindrical sealing strip (4), extending axially from the inside of the top plate (2), and having an outside diameter approximately equal to the bottle neck outside diameter, or slightly larger, and having an inside diameter (2R2) clearly smaller than the bottle neck outside diameter (D). The invention seeks to create a plastic screw top having the above described properties, and which, in the case ofslight damage or deformation of the bottle neck edge, prevents leakage in a more reliable manner, and which should furthermore, if possible, be slightly deformable. The invention also seeks to simplify its production with an injection moulding tool that is as simply built as possible. To this end, the invention proposes that inside the cylindrical sealing strip (4), a further, substantially cylindrical sealing olive-shaped button (3) is radially fitted, the outside diameter (2R1) of which, at least in the area near the top plate and opposite the sealing strip (4), is bigger than the inside diameter (d) of the bottle neck (10) for which the top is intended.

Description

SCREW-CLOSED PLASTIC CLOSURE DESCRIPTION OF THE INVENTION: The present invention relates to a screw-type plastic closure for bottles, consisting of an essentially cylindrical sleeve with an internal thread for screwing onto the external thread of a bottle neck and with a plate essentially a circular disc-shaped upper part as well as a sealing strip extending from the inner side of the upper plate axially inward, the outer diameter of which corresponds approximately to the outer diameter of the neck of the bottle or is slightly larger and whose Internal diameter is clearly smaller than the outer neck edge of the bottle. Such a screw-type plastic closure for bottles is already known from DE 41 28 474. The known screw-in plastic closure has been provided for screwing onto the screw neck of bottles and has such a shape that the approximately cylindrical sealing strip is supported from up and outside on the neck edge of the bottle and thus remains supported by essentially sealing along the rounded upper outer edge of the neck of the bottle or the mouth of the bottle. For this the sealing strip is additionally glued between an approximately cylindrical outer flange and the neck of the bottle and pulled and pressed to REF .: 31091 to remain in a fixed sealing grip with the neck edge of the bottle. Basically, it would also be possible to use plastic bottles, such as PET bottle. In the case of bottles of multiple use of glass is examined visually together and especially also neck and mouth of the bottle before it is used again. However, this can not be prevented by allowing damage to the edge of the neck of the bottle in the area, where the edge comes into engagement with the sealing hood sealing elements, especially if those damages are relatively small and not frequent. Basically it is also for plastic bottles, especially for PET bottles that are finding an extended application. The plastic bottles also have to take into account the damage in the course of manufacturing or handling with some larger manufacturing tolerances that may already come from manufacturing. Small damages, especially in the form of cracks or gaps, are visually difficult to recognize. It can also be presented that full and closed bottles whose neck edge presents slight damage, present deformations or manufacturing inequalities, which when examined are easily seen, but which are enough to influence the sealing grip between the bottleneck edge and the elements sealing the closure lid. This is especially important if the inside of the bottle is under pressure, for example in the case that bottles are used for beverages containing carbonic acid. It is defective sealing can in those bottles lead to the gas leaking from the bottle and in this way lower the pressure, which leads to the disappearance of the carbonic acid contained in the drink, and that after a few days or week of storage the Carbonic acid is completely lost and has correspondingly bad taste. From WO 96/02430 a closure cap is already known, which guarantees a good sealing grip. Instead of an approximately cylindrical seal, this known closure plug has a sealing strip extending approximately horizontally, which is supported on the upper edge of the neck of the bottle, where additionally ring-shaped projections have been provided on the top of the bottle. The top plate or floor of the closure cap, which come into engagement on the side of the sealing strip opposite the neck edge of the bottle, exert a linear sealing pressure on the sealing strip. The expression "olive" gives an intuitive idea of the lower cross section of that part, which has a projecting area towards the outside, which likewise enters into a grip in a linear fashion with the internal cylindrical surface of the neck of the bottle, the internal surface of a neck of the bottle, is less in the PET bottles in the Generally quite accurate, but may present damage, so that the left out of the hermetic olive despite its grip in line with the inside of the neck of the bottle, did not guarantee any secure sealing. The sealing projection on known closure is provided at a considerable distance from the sealing foil in the upper plate so that no high pressure or elastic reaction force is produced in the region of the projection. A sealing foil, which generally extends radially, partially covers the edge of the rounded neck, which is generally well defined, but which may also be damaged. These parts arranged on the axis of the crank in a different manner define a collapse in the form of a blind hole with an important rear cut, which in the manufacture and in the necessary expulsion of the air present serious problems. WO 96/26121 discloses a corresponding screw closure, which has a peripheral sealing foil facing outwards, which must come into engagement with the neck edge of the bottle and additionally a centered application or lobe , whose outer diameter is however somewhat smaller than the internal diameter of the neck edge of the bottle. The lobe thus does not enter in a sealing grip with the inside of the neck of the bottle and especially not with the upper inner edge of the neck of the bottle. Due to the conical shape of the sealing foil is the withdrawal of the mold from that closure from a particularly difficult and complicated injection casting tool. This applies even more for the closure mentioned above according to WO 96/02430, where the sealing foil extends parallel to the upper plate radially in approximately one plane and together with sealing olive which remains inside, with which they define a hollow space almost closed. From EP 0076 778 it is known to cover a closure with a sealing ring and an olive sealing. The sealing ring is narrowed in the diameter directed in an inclined manner inward, so that here too the removal is difficult and also the seal connection of the sealing ring is more bad, since the sealing ring only under pressure rests the bord of the bottleneck and not as in the sealing strip that extends inwardly in the cylindrical essentials from the inner side of the upper plate, and that expands on the neck of the bottle. The known closures have therefore partial problems in the manufacture and especially in the removal of mold and on the other hand they do not guarantee any absolutely secure sealing in the case of small damages deformations of the edge of the neck of the bottle. In contrast to the state of the art, the present invention proposes the task of creating a bolt-on plastic closure with the characteristics mentioned at the beginning. that in case of light damages or deformations of the neck edge of the bottle, better prevent leaks and which can be easily removed from the mold, to facilitate the fabrication in an injection molding tool of the simplest possible construction. This task is solved because the bolt-on plastic closure, in addition to the characteristics mentioned at the beginning, has the additional feature that radially inside the cylindrical sealing strip has provided another essentially cylindrical sealing olive, the outer diameter of which is placed at least in The closeness of the upper plate the region opposite to the sealing strip d is greater than the internal diameter of a bottle neck, for which the closure is provided. While the sealing strip, which is formed approximately as in the case of the granted DE 4 28 474, which achieves a good sealing of the upper edge of the neck of the upper outer bottle, a sealing olive was additionally provided which additionally also seals the internal surface at the upper edge of the neck of the bottle. The latter is achieved because, that sealing olive is also placed in the vicinity of the upper plate and in the opposite region the sealing strip, that is in the region, in which e where the closure applied to a bottle also touches the upper edge of the neck of the bottle, always has an external diameter greater than the inner diameter of the neck of the bottle or the edge of the neck of the bottle, so that the oliv internal sealing is pushed radially inward and with that sealing It rests on the inner surface of the neck edge of the bottle. Due to the diametric conditions for the sealing strip and the sealing olive, it is produced that at a given axial position, especially in the axial region, at which the edge of the neck of the upper bottle is located, the small distance between the sealing strip and the sealing olive should be less than the thickness of the edge of the bottleneck. It is especially preferred in a preferred form of the invention that the light distance between the sealing strip and the sealing olive in the sealed area be less than two thirds, under certain circumstances, to less than half the thickness of the bottle neck. , since the sealing olive as the sealing strip consists preferably of the plastic material of the closure will have sufficient elasticity to apply or screw tightly the closure, or pushed by the edge of the neck of the bottle away, where however, due to the elastic return force that is present, a very strong strong sealing grip with the upper edge of the neck of the bottle will be reached. Additionally, in the preferred embodiment of the invention, it is provided that the sealing olive on the external side has a flat bulge, which in the transversal section has approximately the shape of a triangle with an obtuse angle. Here it must be observed that the thrust of the internal application inwards also means a compression of the material, of which the sealing olive is made. The bulge that has a correspondingly larger external diameter, enters a sealing grip with the inner surface of the bottle neck edge and forces out a strong compression of the material of which the sealing olive consists, and with this an increase in the elastic recovery force, which finally guarantees the secure hermetic grip. At its free end is the sealing olive preferably rounded and / or inclined, so that during axial movement in the direction of the neck of the bottle the sealing olive is actually pressed radially inward and does not settle on the neck edge d bottle or only radially pushed out. Similarly, in the preferred embodiment, the sealing strip at its free end also has a rounded and / or inclined shape, so that with axial movement in the direction of the neck of the bottle s pressed radially outwards, if it enters in grip with the edge of the bottleneck. As a whole, the variants of the sealing strip and the sealing olive can be characterized, because their deviations from an exact hollow cylindrical shape are essentially limited to the external wall of the application or lobe and to the internal wall of the strip. sealing. This is the olive in the preferred embodiment approximately twice as thick or at least 50% longer (in the axial direction) than the sealing strip. Preferably the axial length of the olive becomes up to twice the axial length of the sealing strip. Because of this relatively massive conformation of the sealing olive, in the preferred embodiment of the invention, the deviation of the external diameter of the sealing olive from the diameter of the neck edge of the bottle is weaker, in any case, in the region where the sealing is essentially present, which the corresponding deviation of the internal diameter of the sealing strip with respect to the external diameter of the neck edge of the bottle; since the sealing strip is thinner and shorter and with this it is easily stretchable elastically and movable away from it. Preferably, the outer surfaces of the sealing olive and the internal surface of the sealing ring are spread over the axial stretching of the sealing strip and essentially parallel, that is, the width of the sealing strip is at the length of the sealing strip. approximately constant light between the sealing olive and the sealing strip, and the external surface of the oil thus runs first of all in the axial height of the end of the sealing strip parallel to and to the rounded inclined mold thereof. In the cross-section, the hollow space formed between the sealing olive and the sealing strip has a slightly rounded and concave upper round shape, the lower end of which is open and the upper end closed. The hollow space extending from the bottom up slightly rotated has thus the cross section an essentially constant width only narrows at its rounded closed upper end, where the upper section, in reference to the axis of the closure, is approximately cylindrical, and the lower section is conical widened to the outside, the axial length hollow space is clearly narrower than the thickness of the neck of the corresponding bottle, which defines the length of the outer sealing strip, which in turn is relatively short , so that in its state screwed to the neck of the bottle evenly covers the neck edge of the outer rounded bottle completely. With this, the narrow hollow space between the sealing olive and the sealing strip axially correspondingly short remains, which facilitates the manufacturing process and also the forming of a tool d cast by injection. Specifically, this hollow space has an axial depth (corresponding to the axial length of the sealing strip) of less than 4 mm, preferably less than 3 mm and especially approximately 2 to 2.5 mm. The free end of the sleeve of the screw-type closure is preferably a piece provided with a guarantee or tear strip. As also in general, the closure in the preferred embodiment is made of a single piece of a homogeneous synthetic material by a casting technique or injection. The essentially cylindrical forms of the sealing gasket and the sealing strip and the short axial length thereof allow a relatively simple and easy removal of the mold and correspondingly a tool or mold of correspondingly simple manufacture. Other advantages, characteristics and possibilities of application of the present invention are clearly set forth by means of the following description of a preferred embodiment in relation to the corresponding figures. Don shows; Figure 5 shows the screw closure according to the invention in an enlarged section showing the axis; Figure Ib the bolt-on closure according to the figure in a side view approximately in the original size; and Figure 2 the closure according to Figure 1 in the same axial cutting plane, but in a screwed state on the neck of the bottle. The figure to the screwed closure according to the invention is recognized in a longitudinal section containing the axis. The bolt-on closure consists essentially of a cylindrical liner 1 with a disc-shaped upper plate 2 which is connected to it in one piece. At the free end of the cylindrical liner 1 also sits, in one piece, with the liner 1, a strip of guarantee and tear 7, which s tear by the loosening twist of the screw cap of a bottle or of the shirt 1 and with this characterizes an already open bottle. The cylindrical jacket or layer has a thread interrupted in parts as well as on its external side a grip 9 which must facilitate the application of a moment of rotation to grasp the closure cap with the fingers. The two elements that cause the hemetisation with bottleneck are the sealing strip 4 peripheral cylinder 4 and the olive 3 peripheral sealing equally annular and parallel. How it is recognized, the outer side of the cylindrical sealing strip 4 also runs like the inner wall of the cylindrical olive 3 in a rec cut and with this quite accurately cylindrical. The inter wall of the cylindrical sealing strip 4 runs only p a relatively short section parallel to the axis and is then the direction of the rounded free end and runs inclined outwards. The outer wall of the cylindrical "olive" has a flat edge in the cross section approximately the shape of an obtuse angle triangle, where the obtuse vertex of that triangle defines the maximum external diameter of the application 3 or of the flange and approximately coincides with the free end of the sealing strip 4. Towards the upper plate 2 then the outer wall of the cylindrical sealing olive runs from the flange almost parallel to the end section running inclined and rounded, before it runs again almost parallel to the axis and then transform into an arc in the inner wall of the sealing strip 4. In FIG. 1b the closing is shown approximately the natural size in a side view. It clearly recognizes the bevelling 9 on the outer side of the bolt, which should facilitate the screwing and unscrewing of the closure, as well as the guarantee and tear band 7. In general the closure is shown in figures 1 and 2 exactly on the scale, where the medi R3 is somewhat less than 31 mm. Hence, due to fidelity of the scale in the representation, all the other measurements can be deduced in an exact way and the absolute and relative measurements of all the elements are evident in terms of real scale representation by the Figures. It is understood, however, that the invention is not limited to maintaining absolute and relative measurements of the individual closure lid elements. Also the free end of the sealing olive 3 is clearly rounded, so that the free end of the sealing olive 3, if it hits the edge of a bottle neck, deviates towards and is pushed away. In Figure 2, the plastic screw lock is recognized again in the same cutting plane but in the state of complete screwing on the neck of the bottle. As can be seen, the sealing olive 3 is provided by an internal grip from its rounded libr end with the front surface of the bottle neck 10 pushed forward, the rim remaining on the internal cylindrical surface of the bottle neck. As can be recognized, here the cylindrical olive 3 is pushed in and compressed, so that an elastic recovery force is produced, which causes a firm grip sealing. At the upper outer edge of the neck of the bottle, the sealing is produced by the grip with the sealing strip 4, which by the execution of an internal grip its inclined or rotated free end with the front side d neck of the bottle is pushed out and then into the outer surface of the neck of the bottle and a cylindrical flange 5 is held and the flange is pulled around the upper outer bottle rim, where this rim 5 has provided in the passage between the lid jacket and the upper pla and presents an essentially cylindrical internal surface. With regard to the particularities achieved with the good sealing grip we refer to the DE 41 2 474. Since the sealing olive 3 is clearly coarse and preferably almost has twice as thick (if considering the flange or bulge) that the sealing strip 4, has been provided in the preferred embodiment of the invention, that the external diameter 2RX of the sealing olive, in the area in which the upper edge of the bottleneck enters, grasps, a small difference to the internal diameter of the bottleneck edge in that area, than the sealing strip 4 with internal surface relative to the outer edge of the bottle neck, since the sealing strip 4 with an effect of equal force is more easily deformable than the sealing olive 3. This can also be clearly recognized in Figure 2 and by comparison with Figure i. The diameter difference - 2R between the sealing olive and internal bottleneck edge in the closure does not screw on the bottle neck is only one third to one quarter of the diameter difference D-2r2 between internal surface of the strip of sealing and the edge d external bottleneck. By the closure according to the invention, both the upper outer edge and also the inner surface of the neck of the bottle neck are between two opposite sealing elements. And so be sealed. With this we have two sealings almost equal value and independent of each other, so that in case of damage or defects or tolerances that remain undetectable, there is a high probability that when one of the two hemetizations guarantees a sufficient seal, and that it is unlikely that a deformation damage, which will affect both the upper outer edge and the inner surface of the bottleneck edge, goes unnoticed.

It also exerts the bottleneck on the sealing elements radially opposed forces, which cancel each other. With this, it is avoided that in the usual sealing which is supported on the one hand, the upper plate (or floor of the lid) that receives these forces slowly weakened and with this the sealing grip slowly softens.

It is noted that in relation to this date, the me. ::. Method known by the applicant to take to the prac :; The aforementioned invention is the conventional one for the manufacture of the objects to which it refers.

The invention being described as above, it is said. : omc crcoiedad io content in the following.

Claims (13)

1. CLAIMS 1.- Screw-on plastic closure for bottles consisting of a lid or hood with an essential cylindrical sleeve with internal thread for screwing on the external thread of a bottle neck and with a circular disc-shaped upper plate as well as essentially cylindrical sealing strip extending from the inner side of the upper plate axially, whose outside diameter corresponds approximately to the outer diameter of the bottle neck or slightly exceeds and whose internal diameter is clearly smaller than the outer diameter of the bottle neck characterized in that it is has provided radially inside the cylindrical sealing strip another piece in the form of a sealing oil in essentially cylindrical, whose outer diameter is at least in the vicinity of the upper plate and the region opposite the sealing strip is greater than the internal diameter of the neck bottle, for which the closure was intended, and it provides a bulge or rim radially outwardly of the sealing strip in the passage from the upper plate to the jacket of the closure, which has an inner surface approximately cylindrical, whose internal diameter when equal is greater than and preferably somewhat less than the sum the diameter of the bottleneck and twice the thickness of the sealing strip.
2. 2. Screw-lock plastic closure according to claim 1, characterized in that, the separation distance between the sealing strip and the sealing olive in the sealing region is less than thirds and selectively less than half the thickness of the neck of the seal. bottle.
3. 3. Screw-lockable plastic closure according to claim 1 or 2, characterized in that the sealing olive on its outer side has a planar rim with the cross-section of an obtuse triangle
4. 4. -Closing of screw-retained plastic according to one of the claims 1-3 characterized in that the olive d sealing on a free end in the cross section is so rounded and / or inclined, in its course, that in axial movement on a bottleneck the olive d sealing is pushed radially towards in.
5. 5. - Screw-lock plastic closure according to one of claims 1-4, characterized in that the sealing strip d at its free end is so round and / or inclined, in the axial movement of the closure on the neck of the The bottle is injected radially outwards.
6. 6. Screw-lock plastic closure according to one of claims 1-5, characterized in that the deviations of the cylindrical shape by the olive sealing of the sealing strip are essentially limited to the outer wall of the seal. sealing olive d and the internal wall of the sealing strip
7. 7. Screw-on plastic closure according to claim 1, characterized in that the opposing surfaces of the sealing strip and the sealing oil run parallel to one another. in most of the axial length of the sealing strip.
8. 8. Screw-lock plastic closure according to claim 1, characterized in that the axial length of the sealing olive is at least 50% and preferably 100% greater than the axial length of the sealing strip. .
9. 9. Screw-lock plastic closure according to one of claims 1-8, characterized in that the average thickness of the sealing olive is approximately twice the thickness of the sealing strip.
10. 10. Screw-lock plastic closure according to claim 9, characterized in that the deviation of the external diameter of the sealing olive with respect to the internal diameter of the bottle neck is clearly less than the deviation of the internal diameter of the sealing strip. with respect to the external diameter of the bottleneck.
11. 11. Screw-lock plastic closure according to claim 10, characterized in that the ratio of the deviation is at least 1: 2, preferably from 1: 3 to 1: 5.
12. 12. - Bolt-on plastic closure according to one of claims 1 - 11, characterized in that, lower edge of the jacket is provided with a guarantee and tear band.
13. 13. Screw-lock plastic closure according to one of claims 1-12, characterized in that it is manufactured in one piece and preferably in a homogeneous material.