Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TAMPER-RESISTANT PRESS AND TURN CLOSURE
This invention i3 concerned with ~he provision of a
child-re~i~tant and tamper-resistant clo~ure for a container.
Zeller Plaqtik in their ~ri~ish Patent No. 1,529,999
have described a very effec~ive child resi tant closure which
works on a 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. This invention uses the features of
the press and turn closure as described in Patent
No~ 1,529,999 as the child-resistant feature.
In more detail Patent No. 1,529,999 provides a
child-resistant press and turn clo ure for a container having
an externally screw-threaded neck, the closure being made
rom pla6tics material and comprising a screw cap and overcap
being relatively ~ovable both axially and angularly,
projections on one of said caps and co-operating projections
or recesses on or in tbe other of said caps, said projections
or recesses having irst faces on one side thereof which
co-operate to transmit rotational movement from the overcap
to ~he ~crew cap when the overcap is rotated in a direction
to Acrew the clo~ure onto the neck of a ~aid container and
second faces on the oppo~it ~ides thereof, the ~econd 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
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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 SQ 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 purchas0rs 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.
According to the present invention there is provided
a press and turn closure with a child-resistant press and
turn feature characterized in that the closure is also
provided with tamper-resistant means including a
tamper-evident band connected to the press and turn part of
the closure by frangible means.
In one embodiment when the closure is in position the
tamper-evident band may be held down by engagement with an
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annular projection on an associated container so that when
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. In another similar embodiment
the tamper-evident band is connected by the frangible means
to the skirt of the overcap. In each embodiment the upper
edge of the tamper-evident band is provided with serrations
or fine teeth for co-operation with serrations or fine teeth
on the skirt to which the tamper-evident 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. 1,529,999 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
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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. Full details
of the construction and operation of the press and turn
closure are given in UK Patent 1,529,999 and so further
description will not be given here.
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. ~he 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 ~ith 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 of
the container and is screwed on in the usual way. The act of
screwing the closure onto the container causes the
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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
5 4 turns with the screw cap 2 ~nd the bridge members 5 flex
but do not break. At the end of the movement of the
closure the bead 7 passes over t~e bead 8 and snaps into
I position below the bead 8 as shown in Figure 1. When the
clos~re is to be unscrewed axial downward pressure is
applied to the closure so that the projections or engaging
; dogs with matching recesses on 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 S intact that gives-
evidence that the closure almost certainly has not
previously been removed but if ~he bridge members 5 are
broken the closure has probably been removed an~ 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
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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 lim;ted upward and downward
movement relatively to the screw cap 2, in the manner
described in greater detail in UK Patent No. 15~9999.
It will be noted that the bridge members S have a
reduced or weakened p~rtion at their point of connection
to the skirt of the screw cap 2. An annular deformable
ssealing member is arranged for co-operation with the rim
around the mouth of the container 3 as shown in the
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.
Ihe same references are used in Figure 2 as in ~igure 1,
for the same parts. When the closure is applied to the
container the fine teeth or serrations 9 engage wqth the
fine teeth or serrations 10 and the band 4 turns ~ith
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 ~o the overcap 1 and the closure is turned to
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unscrew it 9 the bead 7 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 serrationsO The container
is preferably made of glass with a special neck
profile, as shown, for co-operation with ~he closure,
but can9 of course, be made from any appropriate
alternatives moulded in various plastic materials or
fabricated in aluminium or sheet metal.
