[0001] This invention is concerned with the provision of an improved tamper-resistant and
tamper-evident container body and closure assembly. The invention also includes an
improved closure for application to the neck of a container body.
[0002] A standard form of container body has a mouth at the top and an external annular
bead around the neck of the body below the mouth and such container bodies are hereinafter
referred to simply as standard container bodies and the external bead around the neck
is hereinafter called a neck ring.
[0003] Manufacturers already have a very substantial investment in moulds and machines for
making such standard container bodies which are made in millions in several sizes
and a demand has grown up to provide an improved tamper-resistant capability for assemblies
using such standard container bodies. In this connection it has already been proposed
in our European Patent No.0080846 to provide a closure comprising a cap part and a
tamper-resistant safety band connected to the cap part by frangible means and provided
with an internal annular bead around the inside of the band so that the bead on the
band snaps over the neck ring on the body when the closure is first applied to the
body whereby the closure cannot be removed from the body to open the mouth until the
band is torn away leaving the cap part free for removal. An arrangement as described
above in general works very well but we have found that the moulding tolerances are
sometimes unduly exacting in the sense that if either the bead on the band or the
neck ring or both is/are oversize difficulty may be experienced in applying the closure
to the body without breaking the frangible means.
[0004] In recent years more and more products have been offered for sale in tamper-resistant
assemblies because of high product value or risk of adulteration and a demand has
grown up for a simple, relatively inexpensive and effective closure for application
to the neck of standard container bodies, whatever the product contained, so that
the product can be offered for sale in tamper-resistant assemblies, using standard
container bodies. In accordance with a feature of this invention we provide a closure
comprising a cap part with a top and a depending skirt and a tamper-resistant safety
band connected to the skirt by frangible means characterised in that the tamper-resistant
band is provided with a plurality of windows hereinafter simply called openings into
which inwardly and upwardly inclined resilient lugs formed on the band project in
such a way that when the closure is first applied to the neck of a standard container
body the lugs are deflected so as to pass over the neck ring on the body and then,
due to their resilience, the lugs snap back inwardly to their original position so
that the upper end or the top of each lug is disposed below the lower surface of the
neck ring.
[0005] It will be understood therefore that in our containuing quest to find tamper-resistant
closures for application to standard container bodies with a neck ring below the thread,
we have in accordance with this invention designed an improved closure that includes
all the required features namely:
1. It has a smooth line exterior profile.
2. It is moulded using 'conventional' splits and thread forms that are 'bumped off'
the core pins so special moulding techniques are not needed.
3. It can be screwed onto the container body or applied axially using conventional
capping machines with no secondary operations or special purpose equipment.
4. It will fit the neck of a standard container body with no special features required
on the neck ring.
5. The frangible nibs will not break during application of the closure but will break
when the closure is first removed.
[0006] To achieve this we have produced for the first time a safety band which incorporates
all the break nibs and driving ratchet/teeth/dog features on its uppar part with a
smooth interior while the locking lugs, which may be formed with the same pair of
splits, are on a lower part. The locking lugs preferably consist of 2 or 3 pairs of
lugs angled inwards and upwards from near the bottom edge of the break ring skirt
and adapted to bend readily out of the way when passing the thread and/or neck ring
of the container. However, once the lugs have clicked past the neck ring into the
normal recess below the ring, the lugs will work like a spring and revert to their
original horizontal top edge so that they become locked beneath the horizontal 'roof'
above them formed by the neck ring and no amount of 'fiddling' will move all the lugs
clear of the neck ring, and the ring must break off whilst unscrewing the closure.
The precise shape of the lugs is not important and they may be produced using mould
side wall openings and the shape of the opening is not important either. Suffice to
say that the openings may be formed by 'conventional splits' in e.g. one, two or three
opposing pairs. The lugs preferably have a 'radial' arrangement in plan view simply
for ease of application to standard container bodies despite the fact that the lugs
are preferably formed by plain opposing splits meeting an inner core pin at 180 to
each other.
[0007] Preferably the lower horizontal edge of each opening is slender, so that each lug
can swivel readily about its pivot point. Otherwise, it will be appreciated that the
lower edge of a lug may jam against the neck ring as the lug passes the ring whilst
swivelling.
[0008] In order that the invention may be more clearly understood, reference is now directed
by way of example to the accompanying drawings in which:
Figure 1 is a part section through a closure according to the invention and a standard
container body forming an assembly according to the invention.
Figure 2 is a part side elevation, part longitudinal section of the closure.
Figure 3 is a part cross-section on A-A part plan of the closure.
[0009] Referring to the drawings it will be noted that the closure has a cap part 1 with
a top 2 and a depending skirt 3, the lower edge of which is connected by frangible
tongues 4 to the upper edge of a tamper-resistant band 5. Teeth 6 are provided on
the lower edge of the skirt 3 for engagement with teeth 7 on the upper edge of the
band 5 to push the band 5 round with the cap part 1 when the closure is being screwed
on for the first time. The cap part 1 has an internal screw thread 8 for engagement
with an external screw thread 9 on the neck of an associated container body.
[0010] The band 5 is provided with openings 10 in the lower part 14 of the band 5, see e.g.
Figure 1.
[0011] An inwardly and upwardly inclined lug 12 is formed on the band 5 along the lower
edge 13 of each opening 10 and each lug 12 may be shaped as shown to avoid sharp pointed
corners that might hinder correct positioning of the lugs as the closure is being
screwed on.
[0012] In operation the closure is initially screwed down on to a filled container body
until the lugs 12 on the band 5 engage with the neck ring 11 on the container body.
Further screwing on causes the resilient lugs 12 to be deflected from their inclined
position into a substantially vertical position as they move pas the neck ring 11.
Finally as soon as the top of each lug 12 has moved past the bottom of the neck ring
11 each lug snaps back into its normal inclined position as shown in Figure 1, so
that each lug 12 then projects into the associated opening 10 with the top of each
lug 12 immediately below the neck ring 11. The closure is now in its tamper-resistant
position because the closure cannot be removed from the container body without mutilation
of the lugs and/or other parts of the closure. For example, an attempt to unscrew
the closure from the body will cause the cap part 1 to rise but the band 5 cannot
rise very far with the cap part 1 because the top of each of the lugs will abut against
the underside of the neck ring 11 and this will lead to the breaking of the frangible
tongues 4.
[0013] It will be understood that a screw-on, screw-off cap has been described as an example.
A push on, push off cap may also be provided in accordance with the invention in which
case on removal of the closure, the band 5 would be separated from the cap part 1
by breaking of the frangible nibs which would make it immediately evident that tampering
or opening had occurred.
1. A closure comprising a cap part with a top and a depending skirt and a tamper-resistant
safety band connected to the skirt by frangible means characterised in that the tamper-resistant
band is provided with a plurality of openings into which inwardly and upwardly inclined
resilient lugs formed on the band project in such a way that when the closure is first
applied to the neck of a standard container body the lugs are deflected so as to pass
over the neck ring on the body and then, due to their resilience, the lugs snap back
inwardly to their original position so that the upper end or the top of each lug is
disposed below the lower surface of the neck ring.
2. A closure for application to a standard container body with a projecting neck ring
wherein the closure has a top, a depending skirt and a tamper-resistant safety band
connected to the skirt by frangible means characterised in that the tamper-resistant
band is provided with a plurality of openings arranged around the band and disposed
in an upper part thereof and further characterised in that a lower part of the band
is provided with a plurality of inwardly and upwardly inclined resilient lugs formed
on the band in such away that when the closure is first applied to the neck of a standard
container body the lugs are deflected so as to pass over the neck ring on the body
and then, due to their resilience, the lugs snap back inwardly to their original position
so that the upper end or the top of each lug is disposed below the lower surface of
the neck ring.
3. A closure according to claim 1 or 2 wherein the lugs are shaped substantially as
shown in Figure 1.
4. A container body and closure assembly comprising a closure as claimed in claim
1 or 2 and a standard container body.