Container and closure

The invention relates to a container neck (10) and closure (12), particularly useful for foil-sealed containers. The neck (10) and closure (12) include complementary threads (14, 16) or projections and complementary tapered surfaces (18, 20) which are adapted to form an interference fit and seal the closure (12) to the neck (10) at a region clear from the lip (30) of the neck (10) and the crown (120) of the closure (12). Any foil seal (28) present on the container neck (10) remains free from contact with the closure (12) during application and tightening. Preferably the neck (10) includes a recessed lip (30, 32) further to protect the seal and to inhibit drop formation. An outer edge of the container lip may be chamfered to provide a pull tab on the foil seal. Additionally, the foil may be of a larger diameter than the lip of the container, so that it provides an overhanging edge of foil to facilitate the removal of the foil, but not of such a large diameter that it touches the inner surface of the closure.

This invention relates to a container closure assembly comprising a 
container neck and a complementary closure. In particular, the invention 
relates to such an assembly in which the neck is adapted to carry a 
sealing web, e.g. a foil seal. 
Foil sealed containers are used for a variety of different purposes, 
particular examples being medicine bottles, coffee jars and drinks 
containers. Commonly, they are used in applications in which the contents 
of the container are consumed or exhausted over a fixed or well-defined 
period of time. In such cases, the foil seal provides that the contents of 
the container remain uncontaminated, or that they retain their original 
quality, until the foil seal is broken. A secondary seal, between the 
container and its complementary closure ensures a degree of protection for 
the contents of the container which is sufficient to preserve the quality 
of the contents throughout its consumption or usage period. 
It has been common practice for the secondary seal to be provided between 
the lip of the container neck and the crown of the closure, which has the 
effect of sandwiching the foil seal between the two. Overtightening of the 
closure can tear or rupture the delicate foil seal. 
This invention seeks to overcome this problem, and accordingly provides a 
container closure assembly comprising a container neck, a container 
closure and a thread for retaining the closure on the container neck, 
wherein the inner surface of a skirt portion of the closure is adapted to 
seal against the outer surface of the container neck. 
With the above arrangement, the secondary seal remains entirely clear of 
the lip of the container neck, and therefore of any foil seal or other 
sealing web which may be provided thereon. 
For additional protection of the sealing web, the assembly may be such 
that, when the closure is engaged with and sealed to the container neck, a 
clearance exists between the outer surface of the lip of the container 
neck and the corresponding inner surface of the closure. 
The invention also provides a container closure assembly comprising a 
container neck, a container closure and means for retaining the closure on 
the container neck, wherein the inner surface of a skirt portion of the 
closure is adapted to seal against the outer surface of the container neck 
and, when the closure is engaged with and sealed to the container neck, a 
clearance exists between the outer surface of the lip of the neck and the 
corresponding inner surface of the closure. 
This clearance may be afforded by providing the outer surface of the lip 
with a recess. Preferably, the recess includes a substantially outwardly 
facing surface which is inclined to the longitudinal axis of the container 
neck so as to form an overhanging rim on the container. Preferably the 
inclination of the recess surface is between about 1.degree. and about 
45.degree., preferably about 20.degree.. 
Preferably, the container neck includes an outwardly tapered portion and 
the inner surface of the skirt portion of the closure is adapted to form 
an interference fit with that tapered portion. This will ensure that no 
contact, other than accidental contact, occurs between the closure and the 
lip of the container neck, or any sealing web thereon, during application 
or tightening of the closure. The skirt portion of the closure can be made 
large enough to pass over the relatively narrow lip of the container neck 
and only seal with the neck in a region where the tapered portion is 
wider. 
To provide a good seal, the skirt portion of the closure preferably 
includes an inwardly tapered surface so as to correspond to the tapered 
neck. Preferably, the angle of taper is between about 1.degree. and about 
45.degree., most preferably about 1.degree. and about 25.degree., and in 
particular about 5.degree.. 
In a case where the container neck and closure are of circular section, the 
means for retaining the closure on the neck preferably includes a thread. 
Most preferably a thread is provided on the closure and a complementary 
thread on the container neck. 
Alternatively, the skirt portion of the closure may be provided with an 
inwardly facing deformable projection to engage a complementary outwardly 
facing projection on the neck. This provides a snap fit closure. 
Preferably, the projections comprise one or more outstanding beads. 
The invention also provides a container neck, adapted to receive a 
complementary closure and having a sealing web sealed thereto, in which at 
least a circumferential portion of an outer edge of the lip of the 
container neck is cut away. This provides that the part of the sealing web 
which overlies the cut away edge may be used as a pull away tab for the 
web. Such an arrangement is particularly useful for webs which are adapted 
to be peeled off. 
Preferably the sealing web is at most coextensive with the lip of the 
container neck. Thus, when the closure is applied, the sealing web is not 
fouled by the closure. 
The cut away edge of the lip may be chamfered, and the container neck, with 
or without the sealing web may form part of a closure assembly according 
to the invention.

The closure consists of a crown portion (120) and a skirt portion (122). 
The skirt portion (122) includes an inwardly tapered surface (20) and the 
container neck (10) includes a corresponding outwardly tapered surface 
(18). A seal (22) exists between the tapered surfaces (18, 20) by virtue 
of an interference fit between the two. 
The lip (30) of the container neck (10) is sealed by a sealing web (28) 
which, in this exemplary embodiment is a foil seal. The neck (10) and 
closure (12) are constructed of materials common in the art, e.g. glass, 
plastics, metal etc. 
As can be seen a clearance (24) exists between the outer surface (26) of 
the lip (30) and the inner surface of the closure (12). The clearance is 
of about 1mm and corresponds to a recess (32) in the lip (30). As can be 
seen, the closure is held away from the edges of the foil seal, to reduce 
the likelihood of tearing the seal. 
Whilst in the embodiment shown in FIG. 1 the clearance (24) is afforded by 
a recess (32) in the lip (30), it will be appreciated by one skilled in 
the art that such a clearance may be provided by an appropriate profile on 
the inner surface of the closure (12), or a combination of profiles on the 
closure (12) and the neck (10). 
The recess (32) includes a substantially outwardly facing surface (26) 
which tapers inwardly away from the open end of the lip. This forms a 
drip-free, overhanging rim. 
The diameter of the inside surfaces of the closure threads (16) is greater 
than that of the sealing web or foil (28). The complementary threads (14, 
16) may therefore be engaged without any portion of the closure (12) 
contacting the sealing web (28). Rotation of the closure (12) advances it 
axially until its tapered surface (20) interferes with that (18) on the 
neck (10). No stress is applied to the sealing web (28). 
The secondary seal (22) between the tapered surfaces (18, 20) has been 
found in shelf tests to be, for practical purposes, of equal integrity to 
the foil seal itself. This offers a substantial improvement over the prior 
art. 
A container closure assembly according to this, or any other embodiment of 
the invention may for example be applied to the container and closure 
which forms the subject of our international patent application PCT 
GB91/00850. 
FIG. 2 illustrates an assembly similar to that shown in FIG. 1, but which 
includes a snap-fit closure. The closure (12) is, in this embodiment, 
formed of deformable plastics material. Its skirt portion (122) is 
provided with an inwardly facing outstanding bead (52) which cooperates 
with an outstanding projection (50) on the container neck. 
Once again, tapered surfaces (18, 20) are provided on the neck and closure 
to provide an interference seal (22). The outer surface of the container 
lip (30) is again provided with a recess (32) which is, practically, 
identical to the recess shown in FIG. 1. The inside diameter of the bead 
(52) is greater than the diameter of the sealing web (28). 
As can be seen, the foil is of a larger diameter than is the recessed 
container lip so as to provide an overhanging edge of foil to facilitate 
the removal of the foil. Nevertheless, the foil diameter is not so large 
that the foil makes contact with the inner surface of the cap. 
FIG. 3 shows the embodiment of FIG. 2 an edge (66) of the lip (30) of which 
is chamfered. The chamfer results in an inclined surface (62) which 
creates a space (64) beneath a peripheral portion (60) of the web (28). 
This peripheral portion (60) performs the function of a pull tab on the web 
(28).and is particularly useful when the web (28) is adapted to be peeled 
off the container lip (30). Of course, the web (28) is still fully sealed 
to the horizontal surfaces of the lip (30). 
It will of course be appreciated that the invention has been described 
above purely by way of example and that modifications of detail may be 
made without departing from its scope.