GB2187177A

GB2187177A - Safety screw cap with break-open seal, for bottleneck type containers

Info

Publication number: GB2187177A
Application number: GB08702231A
Authority: GB
Inventors: Giovanni Celaschi; Emilio Morini
Original assignee: Bormioli Metalplast SpA
Current assignee: Bormioli Metalplast SpA
Priority date: 1986-02-28
Filing date: 1987-02-02
Publication date: 1987-09-03
Also published as: IT8628929V0; ES2002969A6; NL8700436A; IT207686Z2; DE3703007A1; GB8702231D0; FR2595082A1; FR2595082B1

Abstract

A child-resistant screw cap with a tamper-indicating seal comprises a first cylindrical element (1) and a second cylindrical element (2) that interlock by way of ratchet teeth (6, 7), and by way of dogs (8, 10) only on relative axial movement of the two elements. A composite collar (3) is fitted in conjunction with the cap; this consists in a first ring (15) which is gripped by the first cylindrical element, a second ring (16) that constitutes the tamper-indicating seal, and an additional component taking the form of a web (17) which is separated from the collar when the cap is fitted to the neck of the container. <IMAGE>

Description

SPECIFICATION Safety screw cap with break-open seal, for bottle-neck type containers The invention relates to a safety screw cap with a break-open seal for use with containers exhibiting a conventional bottle-neck design.

The main purpose of screw caps of the general type in question, ofwhich numerous embodiments exist, is to provide evidence of the container's having been opened from new, and thus safeguard the consumer in the event of the contents being tampered with. Such screw caps must also afford protection against any unwarranted opening, especially by chiidren, given the potential hazards where access may be gained to toxic or otherwise dangerous contents. Accordingly, the generai practice is to design safety type screw caps in such a way that a combina- tion of more than one movement is required to open them.

Work on the design of these screw caps is aimed at making the cap easier and cheaper to manufacture and assemble, and more readily applicable to the neck of a container by means of automatic machinery.

The object of the invention is that of optimizing the design of such screw caps in such a way as to provide an embodiment that incorporates a break-open seal, affords a reliable guard against unwarranted opening, and is easy and cheap to manufacture whilst being readily and speedily applicable to the neck of a container, employing automatic machinery if so desired.

The stated object can be achieved with a screw cap according to the invention, which is of the type consisting in a first cylindrical element, which con stitutes the cap proper, and a second cylindrical el ementfitted coaxiallyto the first cylindrical element and affording a guard against unwarranted opening, and is characterized in that it comprises a plurality of first teeth issuing from theoutercylindrical wall of the first element, each ofwhich coincides with are lative straight-line cylindrical generator and has one flank merged into the cylindrical profile ofthe wall; a plurality offirst radial dogs arranged in a circular pattern on the topmost outer surface of the first cylindrical element, and a frusto-conical projection located within the circle of dogs and disposedcoaxiallywith the first element; a plurality of second teeth issuing from the inner cylindrical wall ofthe second element, each coinciding with a relative straight-line cylindrical generator and having oneflankmerged into the cylindrical profile of the wall, the purpose of which is to engage with the first plurality of teeth and thus cause the first element to rotate as one with the second element when the second element is screwed onto the neck ofthe container; a plurality of second radial dogs arranged in a circular pattern on the topmost inner surface of the second cylindrical elementand contained within the same circular band as that occupied by the first radial dogs, and a flexible annular projection that registers with the frustoconical projection and is of depth such thatthefirst dogs are held clear of the second dogs by a small margin; a composite collar consisting in a first ring which is gripped inside and underneath the first cylindrical element, a second ring which is connected coaxially with the first ring byway of perforations and constitutes the break-open part of the screw cap, and awebofdiametersmallerthanthe minimum internal diameter of the collar, which is connected coaxiallyto the collar by way of perforations and can be easily separated therefrom. The invention will now be described in detail, byway of example, with the aid of the accompanying drawings, in which: Figure lisa section through the screw cap disclosed, seen in vertical elevation; Figure2 is the horizontal section through ll-ll in figure 1.

The screw cap shown in the drawings comprises a first cylindrical element that constitutes the cap proper, and serves to re-seal the container once hav- ing been opened initially. The type of cap in question will generally be embodied in a relatively rigid moulded plastic, and, as in the case of the cap 1 illustrated, provided with an internal thread that pairs with an external thread offered by the neck of a standard type of container.

The outer cylindrical wall of the first element 1 exhibits a plurality of first teeth 6that coincide with relative straight-line cylindrical generators; one flank of each such tooth 6 is merged into the cylindrical profile of the wall (seefigure 2). The topmost surface of the first element, or cap 1, exhibits a plurality of first radial dogs 8 arranged in circular pattern, and a frusto-conical projection 9 located within the circle of dogs Band disposed coaxiallywith the element 1 itself.

The screw cap comprises a second cylindrical el ement 2, similarly embodied in moulded plastic, which fits over and encapsulates the first cylindrical element, the two elements being coaxiallydisposed following assembly.

The inward-facing cylindrical wall ofthe second element 2 exhibits a plurality of second teeth 7 coinciding with relative straight-line cylindrical generators; one flank of each tooth 7 is merged into the cylindrical profile of the wall. These second teeth 7 are designed to engage the first teeth6 offered bythefirst element 1.

The two sets of teeth 6 and 7 are arranged in such a way as to create a catch mechanism, embodied such that their dissimilar flanks will allow relative anticlockwise rotation of the two elements 2 and 1, but inhibit relative clockwise rotation. In short, the effect of the two sets of teeth 6 and 7 is to permit of screwing the cap onto the neck ofthe container (clockwise rotation), whilst preventing its removal by unscrewing (anticlockwise rotation); it will beobserved, in fact, thatthe merged flanks of the teeth simply ride over oneanotherwhen the second element2 is rotated anticlockwise, such thatthe first element 1 remains stationary.

Itwillbeobservedalsothatthethicknessofthe cylindrical wall of the second element 2 is reduced at the points where the teeth 7 are located, to the end of facilitating passage of the flanks of the second teeth 7 over those of the firstteeth 6. The effect of this reduction in thickness is to enhance flexibility, hence def- ormability, ofthe cylindrical element 2, and thus favour passage of the one set of teeth over the other.

In the event of an attempt being made, forexample, by a small child,to open the container simply byturning the second cylindrical element 2, the parts of the second element2thathave been reduced in thickness will snap back into shape once contact between the merged flanks of the teeth 6 and 7 has ceased, thereby causing the second teeth 7 to strike againstthe outer cylindrical surface ofthefirstel- ement 1 and produce audible warning of such an attempt.

The topmost internal surface ofthe second element 2 exhibits a plurality of second radial dogs 10; these are arranged in a circular pattern similartothat ofthe first dogs Band twill be seen from figure 1 thatthetwo sets of dogs 8 and 10 occupyacommon circular band. The same top internal surface also exhibits a flexible annular projection 11 that comes to rest on the aforesaid frusto-conical projection 9 when the second cylindrical element 2 is fitted over the first cylindrical element 1.

The depth of the annular projection 11 is such that thefirstdogs Swill normally remain clear of the second dogs 10 by a small margin, and no contact can occur between the two sets of dogs 10 and 8 when the second element2 is rotated. Applying light downward pressure to the second element 2, on the other hand, the annular projection 11 will flex and spread over the conical surface of the projecting frustum 9, and thus shorten the distance between the two surfaces from which the sets of dogs 10 and 8 project.

Rotating the second element 2 with downward pressurethus applied, the second dogs 10engage the first dogs 8 and cause the two elements to turn as one,thus enabling the cap 1 to be twisted off, and the container opened.

Releasing downward pressure on the second element 2, the flexible annular projection 11 will spring back into shape and distance the second element 2 from the first 1 once again, thereby disallowing contact between the first and second dogs 8 and 10.

Deformability of the flexible annular projection 11 is enhanced by inclusion of a plurality of slots 12 coinciding with respective axial generators.

To recapitulate, the screw cap can be twisted onto the neck of the container simply rotating the second cylindrical element 2 clockwise, by virtue of the positive contact created between the teeth 6 and 7, whereas to unscrewthe cap 1, downward pressure must be applied to the second element 2 before turning anticlockwise, in order to ensure positive contact between the second dogs 10 andthefirstdogs8.

The screw cap disclosed further comprises a collar 3which, in its turn, incorporates a first ring 15, a second ring 16,andawebl7.

The first ring 15 is gripped inside and underneath the first cylindrical element 1 whereas the second ring 16, which is connected coaxiallywith the first ring 1 5 via perforations, constitutes the break-open seal.

Atthe momentwhen the screw cap isfittedtothe neck of the container, the second ring 16 will lodge beneath a rim with which the neck of a conventional container is generally provided, and cannot thus be twisted offtogetherwith the cap 1 when unscrewed.

Accordingly, the perforations that connect the first ring 15 and the second ring 16will breakapartwhen the cap is removed forthefirsttime, and one is provided with clear evidence of the container's having been opened.

The web 17 is of diameter smailerthan the internal diameter of the collar 3, and rendered integral with the collarvia perforations; more precisely, the perforations connectthe web 17 to the second ring 16, and are designed to break during fabrication of the screw cap, or alternatively, during fitment of the assembled cap to the neckofthecontainer.

The web 17 would therefore be moulded together with the collar3 as a single piece, and mightassume any one of a given variety of shapes according to the ultimate purpose envisaged. In the embodiment of the screw cap illustrated, the web takes the form of a substantially flat disc which, on separating from the second ring 16, is pushed up into the top of the cap, i.e. the first element 1, and provides a simple washer.

In this instance, the cap 1 will be embodied with an internal groove 19 in which the peripheral partofthe disc 17 may lodge.

The web might also be embodied as a dropper, a non-drip pourer, or other contrivance, in which case it will fit snugly into the neck of the container and remain lodged there.

In addition to offering the advantage of permitting fabrication ofthe break-open seal and the web in a single moulding, the embodiment of the screw cap illustrated considerably simplifieS the operations of fitting the cap and the break-opep seal assemblyto the neck of the container. As often as not, such operations are carried out by automatic machinery, and in the case of the disctype web 17 illustrated, which becomes a simple washer, the step of locating the disc in the top of the cap 1 would normally be implemented as a separate stage, prior to fitment of the screw cap to the neck of the container; this is a step which can be eliminated according to the invention, whatever might be the ultimate embodiment ofthe web.

The screw cap disclosed provides signal advantages over conventional types of screw cap, inasmuch as it incorporates a break-open seal and affords a guard against unwarranted opening; a screw cap according to the invention also permits of fabricating an additional componenttogetherwith the cap itself, and fitting both to the neckofa con- tainer in a single operation.

Claims

1. Safety screw cap with break-open seal for bottle-neck type containers, of the type consisting in: - a first cylindrical element (1) constituting the cap proper; - a second cylindrical element (2) fitted coaxiallyto the first element and affording a guard againstun- warranted opening, characterized in that it comprises:: - a plurality of firstteeth (6) issuing from the outer cylindrical wall of the first element, each of which coincides with a relative straight-line cylindrical generator and has one flank merged into the cylindrical profile ofthewall; - a plurality of first radial dogs (8) arranged in a circular pattern on the topmost outer surface of the first cylindrical element, and a frusto-conical projection (9) located within the circle of dogs and disposed axially with the first element;; - a plurality of second teeth (7) issuing from the inner cylindrical wall of the second element, each coinciding with a relative straight-line cylindrical generator and having one flank merged into the cylindrical profile of the wall, the purpose of which is to engage with the first plurality of teeth (6) and thus cause the first element to rotate as one with the second element when the second element is screwed onto the neck of the container; -a plurality of second radial dogs (10) arranged in a circular pattern on the topmost inner surface of the second cylindrical element and contained within the same circular band as that occupied by the first radial dogs, and a flexible annular projection (11 )that registers with the frusto-conical projection and is of depth such thatthe first dogs are held clear of the second dogs by a small margin;; - a composite collar (3) consisting in a first ring (15) which is gripped inside and underneaththefirst cylindrical element, a second ring (16)which is connected coaxially with the first ring by way of perforations and constitutes the break-open partofthe screw cap, and a web (17) of diameter smallerthan the minimum internal diameter of the collar, which is connected coaxially to the collar by way of perforations and can be easily separated therefrom.

2. Screwcap as in claim 1,wherein the thickness ofthe cylindrical wall ofthe second element is reduced immediately adjacent to each ofthe second teeth in order to provide increased flexibility and enhanced deformability.

3. Screw cap as in claim 1, wherein the flexible annular projection exhibits a plurality of slots 112) coinciding with respective axial generators.

4. Screw cap as in claim 1, wherein the top part of the first cylindrical elemept incorporates an internal annular groove (19) in which the peripheral part of the web may lodge.

5. Safety screw cap with break-open seal for bottle-necktype containers substantially as hereinbefore described with reference to the accompanying drawings.