BACKGROUND TO THE INVENTION
[0001] This invention relates to a child resistant closure assemblies comprising a co-operating
container and cap in which anti-rotation means must be overcome to enable the cap
to be rotated to a predetermined angular orientation on the neck of the container
(this position being referred to herein as 'the aligned position') at which one side
of the cap (referred to herein as the 'front of the cap') can be pushed off the neck
in order to open the container.
[0002] In such closure assemblies the cap comprises a top wall and a depending skirt, and
a co-operating circumferential bead and a lug are provided which engage to prevent
the container from being opened, except at the aligned position. At the aligned position
the lug, which is on the inside of the skirt at the front of the cap or on the neck
of the bottle, can pass though a gap in the circumferential bead which is located
on the neck of the container or inside the skirt at the front of the cap, so enabling
the front of the cap to be pushed off the neck of the container in order to open the
container.
[0003] Closure assemblies as described above are referred to herein as closure assemblies
of the kind described.
[0004] In closure assemblies of the kind described, further engageable means are typically
provided on the opposite side of the cap ('the rear of the cap') which disengage from
the container neck on opening, so enabling the cap to be completely removed from the
container. However, said further engageable means could be replaced, for example,
with hinge means which attach the cap permanently to the container.
[0005] The present invention relates particularly, but not exclusively, to a closure assembly
of the kind described which is the subject of our European patent application published
as EP 0500265. In this closure assembly, the further engageable means are provided
on the rear of the cap and which disengage from the container neck on opening, to
enable the cap to be completely removed from the container, and the skirt of the cap
is connected by a number of breakable webs to a circumferentially extending tear-off
band which in its turn is joined by further breakable webs to a continuous circumferentially
extending captive band on the neck of the container. Lugs on the captive band and
on the neck of the container engage to provide the anti-rotation means of the closure
assembly. In this closure assembly the anti-rotation means prevent the cap from being
rotated to the aligned position until the captive band has been disconnected from
the cap by removal of the tear-off band, and removal of the band is tamper-evident.
[0006] Provision of the anti-rotation means in closure assemblies of the kind described
is an additional child-resistant safety feature to that of arranging for the cap to
be removable only in the aligned position.
[0007] However, these child-resistant safety features may be compromised in random instances
of capping in the factory, if it is possible for the cap to be put onto the container
already in the aligned condition, since it could then be possible for a child to remove
the cap without difficulty. Moreover, where there is a tear-off band, it may be possible
to replace the cap without damaging the tear-off band, thereby overcoming the tamper-evidence
normally provided by such a band.
[0008] In the closure assembly which is the subject of our European patent application published
as EP 0500265, there is still some significant child-resistance in instances of capping
in the aligned position, since, until the tear-off band has been removed, the tear-off
band and the captive band make the cap less flexible, and add to the depth of the
skirt, so making it difficult to push up the front of the cap to open the container.
[0009] Nevertheless, development work has been undertaken to increase the child-resistance
of the closure assembly should capping occur in the aligned position, and to promote
tamper-evidence in such a situation. The present invention arises from this development
work.
[0010] According to the present invention, a child-resistant closure assembly of the kind
described is provided with separable means attached to the cap of the assembly by
way of a frangible connection, the assembly comprising detent means on the separable
means and on the neck of the container of the assembly, surfaces of the detent means
being engageable in the cap aligned position to resist the cap being pushed off the
neck of the container until the frangible connection has been broken, said surfaces
being engageable in the cap aligned position.
[0011] Preferably breaking of the frangible connection is arranged to be tamper-evident.
It may, for example, involve the removal of a tear-off band, the absence of which
would be clearly visible.
[0012] Said separable means may itself comprise such a tear-off band, but most preferably
comprises a band such as a captive band which is spaced from the cap by a tear-off
band.
[0013] The detent means on the separable means preferably comprises a surface of the separable
means.
[0014] The detent means on the neck of the container conveniently comprises a projection.
Most preferably a surface of the projection is obliquely angled relative to the direction
of capping of the container, in order to facilitate passage of the separable means
over the projection without damaging the frangible connection of the separable means.
In a preferred embodiment of the invention the detent means on the neck of the container
comprises a projection in the form of a rib which extends around the neck through
less than a quarter of the neck circumference. The detent means on the neck may comprise
a plurality of projections disposed around the neck. Where the neck of the container
is injection moulded, the detent means on the neck is preferably provided on a circumferential
bead on the neck.
[0015] Where the cap is provided with a tear-off band, the detent means on the neck of the
container is desirably located in a gap between the ends of the tear-off band when
capping has occurred in the aligned position. Where the detent means on the neck is
disposed underneath a portion of a tear-off band, the tear-off band is preferably
arranged to deform over the detent means without damaging its connection or connections
to other parts of the closure assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] By way of example only, specific embodiments of the invention applied to the closure
assembly which is the subject of our European patent application published as EP 0500265
will now be described with reference to the accompanying drawings in which:
Figure 1 is a front view of such a closure assembly according to the present invention in
which the cap has been put on in the aligned position,
Figure 2 is a front view of the closure assembly of Figure 1 in which the start of the tear-off
band has been lifted to reveal detent means in the form of a projection on the container
neck,
Figure 3 is a front view of the container assembly of Figure 1 in which the cap and the tear-off
band have been removed, leaving behind a captive band on the neck,
Figure 4 is a front view of part of the container of Figure 1, showing the neck finish of
the container,
Figure 5 is a partial plan view of the container of Figure 1 showing the neck finish of the
container,
Figure 6 is a side view of the neck of the container shown in Figure 4 according to a first
embodiment of the invention,
Figure 7 is an enlargement of part of Figure 6,
Figure 8 is a side view of the neck of the container shown in Figure 4 according to a second
embodiment of the invention,
Figure 9 is an enlargement of part of Figure 8,
Figure 10 is a front view of part of the container according to a third embodiment of the invention,
showing the container with an injection-moulded neck finish,
Figure 11 is a plan view of the neck finish of Figure 10,
Figure 12 is a plan view of a modified closure assembly in which the cap, tear-off band, and
captive band have been removed, and
Figure 13 is a fragmentary side view in section and showing, in area XIV, a fragmentary front
view of the assembly container.
[0017] In the figures, like reference numerals refer to like features and components.
DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
[0018] The closure assembly of Figure 1 comprises an injection-moulded container 1, a cap
2 having a skirt portion 3, and a captive band 4 attached via a tamper-evident tear-off
band 5 and a pair of frangible connections 6 and 7 to the skirt portion 3. Arrows
8 on the skirt 3 and 9 on the container 1 show that the cap has been put on in the
aligned position. The container 1 may be blow-moulded, at least in part.
[0019] A tab 10 on one end of the tear-off band 5 provides a grip for the fingers in removing
the band.
[0020] In Figure 2 the tab 10 has been lifted away from the surface of the container neck
and partly torn away to reveal a detent means on the container neck in the form of
a projection 11. This is partly situated in a gap under the tab 10 before this has
been lifted away, between the ends of the tear-off band 5, and partly under the start
end of the tear-off band 5, which is adapted to flex slightly to accommodate the projection
11 without any significant damage to the frangible connections 6 and 7.
[0021] In this example, the projection 11 comprises a rib which extends around the neck
of the container 1 through less than a quarter of the neck circumference.
[0022] If an attempt is made to remove the cap in the aligned position, before the frangible
connections 6 and 7 have been torn, the lower surface 11a of the projection will be
brought into abutment with an upwardly directed surface 4a of captive band 4, which
constitutes a detent means on the captive band, so resisting removal of the cap.
[0023] Resistance is also offered when the cap 2 is non-aligned.
[0024] Figure 3 shows the closure assembly after the tear-off band 5 has been torn away
and the cap removed, leaving the captive band 4 on the neck. A lug on the cap normally
engages beneath circumferential bead 13 on the container neck to prevent removal of
the cap, except in the aligned position in which the lug can pass through the gap
14 in the bead. The term 'captive band' is normally used to refer to a band which
passes continuously around the neck of a container, but which is left behind after
removal of a tear-off band. In this instance, after having been left behind, the captive
band has no further role, and is free to fall off the neck of the container should
the container be inverted.
[0025] Figure 4 shows the neck finish when the captive band 4 has also been removed. Lugs
12 on the neck, which are normally covered by the captive band, interengage with lugs
on the inside surface of the captive band to form the anti-rotation means of the closure
assembly.
[0026] As can be seen from Figures 5 to 7, the projection 11 in one embodiment has sides
which are substantially rectangular. However, in a second embodiment, shown in Figures
8 and 9, the projection is substantially wedge-shaped in vertical cross section, so
as to present an obliquely angled surface 11b to the tear-off band 5 and the captive
band 4 during capping, so that these can pass easily over the projection without damaging
the frangible connections 6 and 7.
[0027] In the embodiment of Figures 10 and 11, like reference numerals refer to similar
parts to those of the embodiments of Figures 1 to 9. Since the container in this embodiment
is injection moulded, the lower portion of the neck finish has a surface 15 of reduced
diameter in proportion to that of the lower portion of the neck finish of the embodiments
of Figures 1 to 9, to limit material mass and thereby improve the speed of moulding.
However a land 16 is left in the form of a circumferential bead, which protrudes from
surface 15 to a diameter where it lies closely adjacent to the inside surface of a
tear-off band and corresponding in function to tear-off band 5 of the other embodiments.
The projection 11 in this embodiment is provided on land 16.
[0028] In Figures 12 and 13 a container 101 of an injection-moulded closure assembly is
illustrated thereby, the container cap, tear-off band and captive band having been
removed for reasons of clarity. Like the container 1 of Figures 1 to 11, the container
101 may be blow-moulded, at least in part.
[0029] The container 101 is provided with detent means on the neck of the container, comprising
three equi-spaced projections 111 disposed in a ring which is coaxial about the central
longitudinal axis 25 of the container. A single gap 114 is provided in the circumferential
bead 113. One of the projections 111 is aligned with the gap 114 when capping takes
place.
[0030] The non-illustrated container cap, the tear-off band and the captive band of the
assembly are of substantially the same form as cap 2, tear-off band 5 and captive
band 4 of Figures 1 and 2.
[0031] The provision of the plurality of lugs 111, spaced apart around the neck of the container
101 are for three reasons. Firstly, the lugs 111 serve to prevent the captive band
(not shown, but corresponding to captive band 4 of Figure 1) from falling off if the
container, when opened, is inverted. Secondly, the plurality of spaced-apart lugs
111 serve to increase resistance to the container cap (not shown, but corresponding
to cap 2 of Figure 1) being removed, particularly in the cap aligned position, when
the tear-off band is present.
[0032] Increased, that is, compared to the resistance provided by a single lug 11 of Figures
2 and 3. A single lug 11 offers resistance at a single, localised position, whereas
the lugs 111 each offer substantially the same resistance, but at a number of spaced-apart
positions.
[0033] Thirdly, the spaced-apart lugs 111 assist machine-capping, as the cap is centralised
as it sits on the three lugs 111, before being pushed down into place.
[0034] Use of a single lug 11 can result in the associated cap assuming a tilted position
before being pushed down into place, which is undesirable.
[0035] Where possible, any of the features disclosed herein may be added to, or substituted
for other features. For example, the single lug 11 of Figures 10 and 11 could be replaced
by a plurality of lugs, as in Figure 12.
[0036] Other modifications are possible. For example, containers of increased neck size
may employ more than three lugs corresponding to lugs 111. Furthermore, lug dimensions,
particularly width, may vary according to requirements.
1. A child-resistant closure assembly of the kind described is provided with separable
means (4, 5) attached to the cap (2) of the assembly by way of a frangible connection
(6, 7), characterised in that the assembly comprises detent means on the separable
means (11) and on the neck (15) of the container (1) of the assembly, surfaces (4a,
11a) of the detent means being engageable in the cap aligned position (8/9) to resist
the cap (2) being pushed off the neck of the container until the frangible connection
has been broken.
2. A closure assembly as claimed in claim 1, wherein the surfaces of the detent means
are also engageable in a non-aligned position of the cap (2).
3. A closure assembly as claimed in claim 1 or claim 2 wherein the frangible connection
(6/7) is arranged to be tamper-evident.
4. A closure assembly as claimed in claim 3 wherein tamper evidence is apparent by the
removal of a tear-off band (5).
5. A closure assembly as claimed in any one of claims 1 to 4, wherein said separable
means comprise a tear-off band (5).
6. A closure assembly as claimed in claim 5, wherein the closure means comprise a band
(4) which is spaced from the cap (2) by a tear-off band (5).
7. A closure assembly as claimed in any one of claims 1 to 6, wherein the detent means
on the separable means comprise a surface of the separable means.
8. A closure assembly as claimed in any one of claims 1 to 7 wherein the detent means
on the neck of the container comprises one or more projections (11, 111).
9. A closure assembly as claimed in any of claims 1 to 8, provided with a plurality of
said projections (111), distributed around the neck of the container (101) of the
assembly in an equi-spaced manner.
10. A closure assembly as claimed in claim 8 or 9, wherein a surface (11b) of said one
or more projections (11) is obliquely angled relative to the direction of capping
of the container, in order to facilitate passage of the separable means (4, 5) over
the projection (11) without damaging the frangible connection of the separable means.
11. A closure assembly as claimed in claim 8, 9 or 10, wherein said one or more projections
comprise a rib (11) which extends around the neck of the container through less than
a quarter of the neck circumference.
12. A closure assembly as claimed in any one of claims 1 to 11 wherein the neck of the
container is injection moulded, and said detent means (14) on the neck is provided
on a circumferential bead (13) on the neck.
13. A closure assembly as claimed in any one of claims 6 to 12, wherein the detent means
on the neck of the container is located in a gap (14) between the ends of the tear-off
band (5) when cap (2) ping has occurred in the aligned position.
14. A closure assembly as claimed in any one of claims 6 to 13 wherein the detent means
(11) on the neck is disposed underneath a portion of the tear-off band.
15. A closure assembly as claimed in claim 14, wherein the tear-off band (5) is arranged
to deform over the detent means without damaging its connection or connections to
other parts of the closure assembly.