EP0127943B1

EP0127943B1 - Tamper-resistant press-and-turn closure

Info

Publication number: EP0127943B1
Application number: EP84302933A
Authority: EP
Inventors: Eugene Edward Davis
Original assignee: Johnsen and Jorgensen Plastics Ltd
Current assignee: Johnsen and Jorgensen Plastics Ltd
Priority date: 1983-05-09
Filing date: 1984-05-01
Publication date: 1987-03-04
Also published as: ZA843474B; CA1283628C; GB8312691D0; AU563242B2; DE3462473D1; AU2764684A; EP0127943A1

Description

This invention is concerned with the provision of a child-resistant and tamper-resistant "Press and Turn" closure for a container. As a typical example of a Press and Turn closure Zeller Plastik in their British Patent No. 1529999 have described a very effective child resistant closure which works on the press and turn principle. That closure can be screwed on to the neck of a container to close the mouth but it cannot be unscrewed without at the same time applying top pressure to the closure.
For the sake of brevity and clarity the expression "a closure with a child-resistant press and turn feature" will be used in this specification to indicate that this invention includes a child-resistant part of the closure incorporating a press and turn feature. The expression "the Press and Turn part of the closure" will also be used to refer to that part of the closure in accordance with this invention that incorporates the press and turn feature i.e. that part of the closure that is above the arrow A in Figure 1 of the appended drawings. In more detail Patent No. 1529999 for example provides a child-resistant press and turn closure for a container having an externally screw- threaded neck, the closure being made from plastics material and comprising a screw cap and overcap being relatively movable both axially and angularly, projections on one of said caps and cooperating projections or recesses on or in the other of said caps, said projections or recesses having first faces on one side thereof which cooperate to transmit rotational movement from the overcap to the screw cap when the overcap is rotated in a direction to screw the closure onto the neck of a said container and second faces on the opposite sides thereof, the second face of each projection or recess of one of said caps being a cam face whereby, in use, the overcap will rotate relative to the screw cap with said projections or recesses of the different caps camming past one another when the overcap is rotated in a direction to unscrew the closure from the neck of a said container unless the overcap is moved axially relative to the screw cap so that each said cam face is engaged by an edge of the second face of a projection or recess of the other cap with a force sufficient to overcome the cam action.
The Press and Turn closure is very efficient as a child-resistant closure but it is not tamper-resistant and recent events in USA have shown that it is desirable to sell certain products e.g. food, medicaments, toilet preparations and so on in containers with tamper-resistant closures so that purchasers can see whether the container has been opened. However, once opened legitimately by the purchaser, it is essential with products hazardous to children that the package remains child-resistant. It is therefore an object of the present invention to provide a Press and Turn closure with a tamper-resistant feature.
In USA Patent No. 3837518 there is disclosed a tamper proof and child proof closure for a medicine bottle or the like. One problem with the closure disclosed in USA Patent No. 3837518 is that the closure can be used only with a container having a shoulder on which the band initially rests. In Patent No. 3837518 it is essential that the safety band has an axial length such that it is interposed between the bottom of the overcap and the shoulder on the container to prevent the overcap from being pressed down until the band is removed. This is rather a disadvantage because many customers now prefer to use substantially cylindrical containers.
Therefore, the present invention relates to a Press and Turn closure of the type defined in the first part of claim 1 and known e.g. from US-A-3 837 518 and having all the features specified in the second part of claim 1, such that when the Press and Turn closure is in position the safety band may be held down by engagement of said anchor-means with an annular projection on an associated container so that when the closure is removed the frangible means, which connect the band to the skirt of the screw cap of the Press and Turn part of the closure, are broken. The safety band may be connected by the frangible means to the skirt of the inner-screw cap or to the skirt of the outer overcap. In each embodiment the upper edge of the safety band is provided with the serrations or fine teeth for co-operation with the serrations or fine teeth on the skirt to which the safety band is connected.
Each of the two embodiments may be assembled and applied to the container in one screwing- on operation.
In order that the invention may be more clearly understood reference is now directed to the accompanying drawings given by way of example in which:

Figure 1 is a sectional side elevation of a first embodiment of the invention, and
Figure 2 is a sectional side elevation of a second embodiment of the invention,

Referring first to Figure 1, the closure may conveniently be divided into two parts, firstly a child-resistant part disposed above the arrow A and secondly a tamper-resistant part disposed below the arrow A.
The child-resistant part is a standard Press and Turn closure as described in UK Patent No. 1529999 and comprises an overcap 1 and a screw cap 2, the screw cap 2 can move axially within the overcap 1 and when once in position on the neck of a container 3 overcap 1 can be turned freely in relation to the screw cap 2 as long as projections on the screw cap and the overcap are not caused to interlock by the application of axial pressure to the overcap.
To provide a tamper-evident feature for the closure the screw cap 2 has a tamper-evident band 4 connected to the bottom of the skirt of the screw cap 2 by frangible bridge members 5 disposed in gaps 6 in the band 4. The band 4 also has an internal annular bead 7 to engage below an external annular bead 8 on the neck of the container 3. The lower edge of the skirt of the screw cap 2 has serrations or fine teeth 9 to engage with serrations or fine teeth 10 on the upper edge of the band 4 when the closure is being screwed onto the container.
In operation the closure is applied to the mouth or neck of the container and is screwed on in the usual way. The act of screwing the closure onto the container causes the screw cap 2 to move slightly towards the band 4 due to pressure being applied to the closure and this causes the fine teeth or serrations 9 to engage positively with the fine teeth or serrations 10 on the band 4 so that the band 4 turns with the screw cap 2 and the bridge members 5 flex but do not break. At the end of the movement of the closure the bead 7 passes over the bead 8 and snaps into position below the bead 8 as shown in Figure 1. When the closure is to be unscrewed axial downward pressure is applied to the closure so that the projections or engaging dogs engage with matching recesses on the screw cap 2, the two parts begin to turn together and the screw cap 2 with the overcap 1 begin to rise. However, the band 4 resists turning, because the bead 7 has settled firmly below the bead 8. The frangible bridge members 5 therefore break as the closure is being removed.
It will therefore be understood that if a closure is in position with the bridge members 5 intact that gives evidence that the closure almost certainly has not previously been removed but if the bridge members 5 are broken the closure has probably been removed and the contents of the container may have been tampered with or contaminated. In order to minimise the risk of a child removing the overcap altogether the overcap has an annular projection 11 which, in operative position, is disposed below an annular projection 12 on the screw cap in such a position that the overcap 1 can undergo limited upward and downward movement relatively to the screw cap 2, in a manner described in greater detail in UK Patent No. 1529999.
It will be noted that the bridge members 5 have a reduced or weakened portion at their point of connection to the skirt of the screw cap 2. An annular deformable sealing member is arranged for co-operation with the rim around the mouth of the container 3 as shown in drawing.
The second embodiment of the invention differs from the first embodiment in that the tamper-evident band 4 is connected to the overcap 1 instead of to the screw cap 2. The same references are used in Figure 2 as in Figure 1, for the same parts. When the closure is applied to the container the fine teeth or serrations 9 engage with the fine teeth or serrations 10 and the band 4 turns with the screw cap 2 until the bead 7 is in the position shown in Figure 2, below the bead 8 on the container 3. Alternatively, the screw cap 2 can be first applied and the overcap 1 can be applied by top pressure only as a secondary sealing operation. When axial pressure is applied to the overcap 1 and the ciosure is turnea ₁₀ unscrew ii, the oeaa _/ engages with the bead 8 as the overcap 1 is moved upwardly and the band 4 is held down so that the frangible bridge members break as in the first embodiment.
The closure in both its embodiments is preferably made of a suitable resilient plastics material by a moulding operation and as shown we prefer to provide the overcap with vertical serrations. The container is preferably made of glass with a special neck profile, as shown, for co-operation with the closure, but can, of course, be made from any appropriate alternatives moulded in various plastic materials or fabricated in aluminium or sheet metal.

Claims

1. A closure with a child resistant press and turn feature for closing the mouth of a container having a screw-neck finish wherein the closure has an inner screw-cap (2) with a depending inner skirt adapted to engage with the screw-neck of the container, an outer overcap (1) with an outer skirt surrounding the screw-cap (2) and, a tamper evident safety band (4) held in position by frangible means (5) and drive means on the inner screw-cap (2) and the outer overcap (1) of the closure which are interengageable with another in use to allow the inner part (2) to be unscrewed from the container only when the safety band (4) has been removed and only be related axial engagement between the outer overcap (1) and the inner screw-cap (2) during unscrewing, whereby the closure is tamper-evident and child-resistant until the separation of the safety band characterised in that the safety band (4) is adapted when in position to engage with the container to form anchor means (7, 8) and to be held down thereby so that the closure can if desired be used with a container with a substantially cylindrical outer profile i.e. without a projecting collar and further characterised in that the upper edge of the safety band (4) is provided with fine teeth (10) for co-operation with fine teeth (9) on the lower edge of the skirt to which the safety band (4) is connected.

2. A closure according to claim 1 characterised in that the safety band (4) is held down against upward movement by engagement with an annular projection on an associated container so that when the closure is removed frangible means (5) are broken.

3. A closure according to Claim 1 characterised in that the safety band (4) is connected by the frangible means (5) to the skirt of the inner screw cap of the Press and Turn part of the closure.

4. A closure according to Claim 1 characterised in that the inner screw cap (2) of the Press and Turn part of the closure has a tamper evident safety band (4) connected to the bottom of the skirt of the screw cap (2) by frangible bridge members (5) disposed in gaps (6) in the safety band (5).

5. A closure according to Claim 7 characterised in that the band (4) has an internal annular bead (7) to engage below an external annular bead (8) on the neck of an associated container.

6. A closure according to claim 1 characterised in that the overcap (1) has an annular projection (11) which, in operative position, is disposed below an annular projection (12) on the screw cap.

7. A closure according to claim 1 wherein the frangible means (5) have a reduced portion at their point of connection to the skirt.