Title of Invention

CHEMICAL COMPOUNDS

Abstract

A plastic cap(16) with a tamper-evident screw threaded closure for containers(l0), said closure comprising a cap having a top wall(18) and a depending skirt(14) and an internal screw thread, the lower edge of said skirt being joined to an integral detachable tamper-evident band(24) by a plurality of circumferentially spaced frangible elongated straight web bridges(26) across a breaking line(13) separating the lower edge(30) of the skirt and the tamper evident band, and at least one co-operating driving tooth(22) on said skirt and another at least one wedge shaped notch(28) on said band which come into mutual spaced apart contact when said closure is fitted or screwed onto the neck of a co-operating container, wherein said space between the tooth and the notch constitute a detent when the cap is screwed around the neck over the mouth of the containment means to prevent the cap from being prized off and to be held in place independent of the beading and to allow for a play to create a torque to be generated for circumferential rotation for unscrewing a sealed cap to facilitate breaking of the web bridges(26) between the skirt and the cap.

Full Text

FORM-2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE Specification SECTION-10 A PLASTIC CAP WITH A TAMPER EVIDENT SCREW THREADED CLOSURE FOR CONTAINERS ORIGINAL 114/MUM/2000 MIPAK PLASTICS PRIVATE LIMITED of 16 Khetan Bhavan, 198, J.Tata Road, Churchgate, Mumbai 400 020, Maharashtra, India, an Indian Company THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED:- GRANTED 14-9-2004 This invention relates to a plastic cap for containers and more particularly, to a plastic cap with a tamper-evident screw-threaded closure. The present invention also relates generally to tamper-indicating plastic closures for containers, and more particularly to a tamper-indicating closure having a preferentially strengthened frangible connection between a skirt portion of the closure and the closure tamper-evident band to facilitate high-speed closure application while resisting premature detachment of the tamper-evident band. Numerous plastic caps are known which are used to close any type of container. The caps have a tamper-evident band, which serves to indicate that the closed container has not been previously opened. During a first attempt at opening the container, the tamper-evident band will snap open, so that a consumer can readily note that the container is no longer closed in the original way. Tamper-indicating plastic closures have found widespread acceptance in the marketplace for use on containers for beverages and food products, as well as for non-food items. The invention relates to tamper-evident closures for containers. In recent years, it has become increasingly desirable, and indeed necessary, to provide such containers with sealed closures, which cannot be opened and then re-closed without the fact being apparent to a subsequent user. Even with non-pharmaceutical products it is desirable to prove to purchasers that the goods he is buying have not been tampered with before sale. Many such closures have been proposed, almost all of them involving some kind of web or webs which break when the closure is first removed. The problem lies not only in arranging that the webs should break reliably and inevitably when intended, but also in designing the closure so as to be easy to fit to the container, preferably by automatic machinery, and in designing the closure so as to be easy to fit to the container, preferably by automatic machinery, and in particular without involving any delicate or additional steps, such as swaging or welding or heat-sealing. A further problem lies in making the closure assembly easy to mould and in particular to strip from the mould after forming i.e. preferably to is able to mould it in a two-part tool substantially free of undercuts. Finally, metal caps are known which are subjected to a forming as well as a cutting process during a single manufacturing operation. However, processes of this type cannot be applied to plastic caps of the type addressed here because the plastic forming process cannot be combined with a cutting operation. A typical example of a screw-threaded closure designed with these points in mind is one in which a separate skirt on an internally threaded cap is joined integrally by thin breakable webs to a band which engages under an annular bead formed on the neck of the container below the external screw thread on the latter. When the cap is first screwed onto the container the band expands sufficiently to snap over the bead on the neck of the container, the profile of inside of the band and of the bead being appropriate to assist this, that is to say, being of saw-tooth shape in cross-section. In another similar construction the inside of the band has a saw-tooth profile to allow it to pass over the bead on the neck of the container when the cap is first applied but to resist upward movement of the band when the cap is first unscrewed. Again there are interengaging driving teeth between the skirt of the cap and the tamper-evident band to act as drivers on first fitting of the cap, relieving the breakable webs of the driving torque. In one version these teeth are of saw-tooth profile as viewed radially, so that when the cap is unscrewed and the webs are broken the co-operating inclined surfaces of the teeth assist in forcing the cap upwards away from the band. With the known arrangements there is still the danger that a determined and careful tamperer can lever the cap and band off together without breaking the webs. This is partly because the cap has to be of material, which is sufficiently flexible to allow the band to stretch and pass over the bead on the neck of the container on first assembly. It is also attributable to the fact that in practice it is difficult to make either the bead on the inside of the band or the bead on the neck of the container truly sharp and square in profile; more often than not they are both of appreciably rounded shape, and so one can be forced one over the other also in the releasing direction. Tearable tamper-evident bands are also provided in containers with a tearable tongue extending from the band. Often the tongues break off during the tearing operation making it difficult for the user to tear off the band which has to be then manually cut off or excessive force has to be applied to prize off the cap. The aim of the invention is to overcome these drawbacks and to provide a tamper-evident screw-threaded closure assembly of the kind described which is easy to apply using existing automatic machinery, and without the webs being Inadvertently broken during the capping step, yet is almost impossible to remove without breaking the webs. According to the invention there is provided a plastic cap with a tamper-evident screw threaded closure for containers, said closure comprisirig a cap having a top wall and a depending skirt and an internal screw thread, the lower edge of said skirt being joined to an integral detachable tamper-evident band by a plurality of circumferentially spaced frangible elongated straight web bridges, and at least one co-operating driving tooth on said skirt and another at least one wedge shaped notch on said band which come into mutual spaced apart contact when said closure is fitted or screwed onto the neck of a co-operating container, said tooth and notch providing a detent that resists rotation in the sealed configuration of the closure and wherein said space between the tooth and the notch constitute a play to allow a torque to be generated for circumferential rotation for unscrewing a sealed cap to facilitate breaking of the web bridges between the skirt and the cap. Thus sealing engagement is achieved in that the tamper-evident closure is in the form of a tamper-evident band which does not rely on a bead that resists upward movement but on circumferentially spaced one or more detents that resist rotation, and furthermore the webs extend in vertical or inclined directions between the skirt and the tamper-evident band. By having detents, which resist rotation of the band, it is ensured that the webs are broken positively as soon as the user starts to unscrew the cap, as there is a direct circumferential load on the webs, and no reliance is place on resisting upward movement of the band. In practice there may be at least a vestigial bead on the neck of the container, but this is merely to prevent the band falling off after cap has been removed. According to the invention this is achieved in that the tamper-evident band does not rely on a bead that resists upward movement but on circumferentially spaced detents that resist rotation, and furthermore the webs extend in straight or inclined directions between the band and the skirt of the side wall of the cap . Therefore in accordance with this invention there is provided a plastic cap with a tamper-indicating screw threaded plastic closure which includes a tamper-evident band at least partially detachably connected to a skirt portion of the closure by a frangible connection. The frangible connection comprises a plurality of circumferentially spaced frangible bridges, which fracture attendant to removal of the closure from an associated container to provide visually discernable evidence of opening. In order to facilitate high-speed application of the closure to a container, one or more regions of the frangible connection are preferentially strengthened by the provision of relatively strengthened frangible bridges. In a tamper-evident screw-threaded closure of the kind in which the skirt of a cap is joined at its lower edge to a band by integral elongated breakable webs the webs are associated with co-operating teeth and notches that drive the band during the unscrewing and bridge breaking operation. It is, therefore, the object of the invention to create a plastic cap, with which the above-stated disadvantages do not occur. Particularly preferred is an exemplified embodiment of a cap, which is characterized in that the position of the vertical incisions is chosen in dependence on the arrangement of the holding webs, which hold the band, segments that occurs during the snapping open onto the skirt of the cap. By choosing the distance between the vertical incisions in dependence on the holding webs, which do not tear off during the snapping open of the tamper-evident band, the vertical incisions are placed in an area of the tamper-evident band which during the first opening experiences a maximum deflection, in the axial as well as in the radial direction. This ensures a snapping open of the vertical incisions. Particularly preferred is an embodiment of the cap, with which the vertical incisions are bridged by webs. This avoids that after manufacture of the cap, during its storage or transport, but also during the first putting on, the vertical incisions can be damaged, so that a consumer could possibly draw false conclusions about the container having been interfered with. This increases the certainty of the indication of manipulations even further. According to this invention therefore is provided a plastic cap with a tamper-evident screw threaded closure for containers, said closure comprising a cap having a top wall(18) and a depending skirt(14) and an internal screw thread, the lower edge of said skirt being joined to an integral detachable tamper-evident band(24) by a plurality of circumferentially spaced frangible elongated straight web bridges(26) across a breaking line(13) separating the lower edge of the skirt and the tamper evident band, and at least one co-operating driving tooth(22) on said skirt and another at least one wedge shaped notch(28) on said band which come into mutual spaced apart contact when said closure is fitted or screwed onto the neck of a co-operating container, wherein said space between the tooth and the notch constitute a detent when the cap is screwed around the neck over the mouth of the containment means to prevent the cap from being prized off and also to be held in place independent of the beading and to allow for a play to create a torque to be generated for circumferential rotation for unscrewing a sealed cap to facilitate breaking of the web bridges between the skirt and the cap. Typically, the web bridges may be operatively vertical or inclined across the end of said breaking line and the web bridges are thinner than the teeth . BRIEF DESCRIPTION OF THE DRAWINGS In the following the invention will be explained in greater detail with reference to the figures, wherein: FIG. 1 shows a front elevation of the container in accordance with this invention having a sealed cap in its sealed configuration; FIG. 2 shows a front elevation of the cap for the container shown in Fig 1; FIG. 3 is a top view of the container and cap according to FIG. 1. Figure 4 are a partial sectional view of the container of Figure 1 showing the various headings and steps provided at the mouth region of the container to secure the cap thereto; Figure 5 shows a sectional view of the container shown in Figure 1; and Figure 6 shows the tamper-evident band secured to the skirt of the cap shown in Figure 1 and 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings a container in accordance with this invention is indicated generally by the reference numeral 10. The container 10 comprises a containment element 12 and a cap 16. The containment part 12 may be a bottle or a jar resting on a base 34. The cap 16 described in the following can be used universally. It is used preferably to close bottles or jars which are provided on the outside, underneath their mouth area, with a screw thread [not particularly illustrated but which will be obvious to one skilled in the art] and furthermore have a stepped area and headings which co-operates with cap and the tamper-evident band. FIG. 1 shows a cross-section through a cap 1 before it is put onto a to be closed container. The cap has a flat top 18 and a round closed side wall skirt 14. In the bottom edge part 30 of the skirt 14 a tamper-evident area is provided, in this case in the form of a tamper-evident band 24, which is joined to the rest of the skirt by tear-off webs 26, the tear-off webs bridging a predetermined breaking line 13 which is provided by making a horizontal incision in the wall of the skirt 14 in the region separating the bottom edge part 30 and the tamper-evident band 24. In the sealed configuration seen in FIG 1, the cap 16 and particularly the tamper-evident band extending therefrom tightly abuts against beading 32 formed in the wall of the containment element 12. The web bridges 26 furthermore bridge the predetermined breaking line 13 which extend practically circumferentially over the entire length of the tamper-evident band 24. The tear-off webs 26 are formed by material strips, which are provided on the inside surface of the skirt and extend in the longitudinal direction of the cap 16. From FIG. 1 it can be noted that the tear-off webs are considerably narrower than the, which is in each instance associated with a band segment produced by the snapping open of the tamper-evident band 24. On the outer surface of the skirt, ribs 20 are provided extending in the axial direction, which improve the grip of the cap. Between the web bridges 26 there are vertical incisions, which extend over the entire height of the breaking line 13. Between the lower edge 30 of the skirt 14 and the band 24, at least at two regions the edge 30 extends into a tooth formation 22. Complementary to these two tooth formations the tamper evident band 24 has a wedge shaped notch 28. The tooth 22 is seated in the wedge notch 28 in a spaced apart configuration. This tooth and wedge combination form a detent relation ship effectively locking the cap on the neck region of the mouth of the container 12. However the spaced after configuration also permits play to generate torque when a user grips the cap at the skirt region assisted by the ribs 20 and tries to unscrew a sealed cap. Application of a little torque causes the web bridges 26 to break and the cap is then unscrewable from the mouth of the container 12 the cap separating from the tamper evident band 24 along the breaking line 13. The bridging webs 26 can be formed in that during the making of the vertical incisions, a knife provided with a groove is used (not shown), which leaves part of the wall of the tamper-evident band 24 intact. It has been found that especially with the particularly stable design of the cap is further aided with the help of gripping and reinforcing ribs 20 provided on the sidewall of the cap 20. Very high snapping open forces can be introduced into the gripping actions by the play provided in the detent region formed between the notch and the tooth. An extremely high operational reliability is obtained, based on which any interference with the cap will with a particularly great certainty lead to a snapping open of the vertical incisions, so that the consumer can securely recognize an originally closed container. Figure 4 illustrates a front plan view of a jar 12 having an open mouth region 36 defined in a neck region over which the cap 16 seen in Figures 1 and 2 can be mounted. The neck region was a series of headings 38 and 32 and recesses 40r42 and 44 in which the cap and the dependent skirt of the cap 16 can be fitted and screwed on as seen in Figure 1 and 5. Figure 6 shows a plan view of the tamper evident band 24 showing the web bridges 26 and the notch 28. Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. We Claim: 1. A plastic cap(16) with a tamper-evident screw threaded closure for containers(lO), said closure comprising a cap having a top wall(18) and a depending skirt(14) and an internal screw thread, the lower edge of said skirt being joined to an integral detachable tamper-evident band(24) by a plurality of circumferentially spaced frangible elongated straight web bridges(26) across a breaking line(13) separating the lower edge(30) of the skirt and the tamper evident band, and at least one co-operating driving tooth(22) on said skirt and another at least one wedge shaped notch(28) on said band which come into mutual spaced apart contact when said closure is fitted or screwed onto the neck of a co-operating container, wherein said space between the tooth and the notch constitute a detent when the cap is screwed around the neck over the mouth of the containment means to prevent the cap from being prized off and to be held in place independent of the beading and to allow for a play to create a torque to be generated for circumferential rotation for unscrewing a sealed cap to facilitate breaking of the web bridges(26) between the skirt and the cap. 2. The plastic cap as claimed in Claim 1, wherein the web bridges(26) may be operatively vertical or inclined across the end of said breaking line. 3. The plastic cap as claimed in Claim 1, wherein the web bridges are thinner than the teeth . 4. A plastic cap with a tamper evident screw threaded closure for container as claimed in claim 1 and as described herein with reference to the accompanying drawings. Dated this 19th day of December 2000. Mohan Dewan Of R. K. Dewan&Co., Applicants' Patent Attorney

Documents:

114-mum-2000 - claims (granted) - (14-9-2004).doc

114-mum-2000 -form 2 (granted) - (14-9-2004).doc

114-mum-2000-cancelled pages(20-05-2003).pdf

114-mum-2000-claims(granted)-(14-09-2004).pdf

114-mum-2000-correspondence(10-06-2004).pdf

114-mum-2000-correspondence(ipo)-(11-08-2006).pdf

114-mum-2000-drawing(14-09-2004).pdf

114-mum-2000-form 1(20-12-2000).pdf

114-mum-2000-form 19(28-08-2003).pdf

114-mum-2000-form 2(granted)-(14-09-2004).pdf

114-mum-2000-form 3(20-12-2000).pdf

114-mum-2000-power of attorney(20-12-2000).pdf

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