[0001] The present invention relates to the capping of bottles, and in particular to the
use of crown closures. Such closures are long established for the capping of glass
and, more recently, plastics bottles. They traditionally consist of a top panel lined
with a sealing compound, and a peripheral skirt which is crimped onto the bottle to
close it. The closure is removed with a traditional bottle opener, or in some cases
can be twisted off of a threaded finish on the bottle.
[0002] The present invention seeks to provide an improved method for the capping of bottles,
and an improved closure for use therein.
[0003] Accordingly there is provided a method of capping a bottle comprising the steps of:
i) providing a metallic crown closure including a centre panel, and a peripheral skirt
portion depending downwardly therefrom, the distal end of the skirt portion being
curled to form a curl portion;
ii) locating the crown closure over the neck of a bottle, the neck of the bottle including
an outwardly extending capping bead; and
iii) reforming of the crown closure to move at least a part of the curl portion under
the capping bead, thereby securing the crown closure onto the neck of the bottle.
[0004] The above method results in a bottle closed with a crown closure which creates a
distinctive appearance. Furthermore, the curl portion serves to maintain the cut edge
of the metallic closure away from the surface of the bottle. Thus, even if rust starts
to form on the edge of the closure, e.g in hot and humid climates such as the Far
East, this rust is not deposited on to the bottle surface when the closure is removed.
[0005] The crown closure is preferably provided with an outwardly facing curl portion, and
preferably also comprising more than 360° of material when viewed in cross section.
Typically the reforming step acts to roll the curl portion downwardly with respect
to the centre panel. The curl portion is partially unrolled during the reforming operation
as it is moved under the capping bead. Preferably the reforming step acts to roll
the curl portion such that there is still more than 270°, and preferably 360° of material
when viewed in cross section, after the curl portion has been moved under the capping
bead. Optionally the reforming step also acts to tighten the curl portion as it is
moved.
[0006] According to one arrangement, the reforming step moves the entire curl portion under
the capping bead. The method preferably includes a reforming step comprising contacting
the curl portion with an annular tool having a tapered infeed portion, and moving
the annular tool downwardly to move the curl portion under the capping bead on the
bottle. Conceivably, the tool has a generally conical shape, at least in respect of
its curl contacting surface.
[0007] Alternatively the reforming step comprises contacting the curl portion with a tool
having a plurality of projections thereon, and moving the projections with respect
to the curl portion so as to form a fluted arrangement in which a plurality of sections
of the curl portion are moved under the capping bead of the bottle. This arrangement
is particularly suited for the capping of crown closures having significantly more
than 360° of material in their curl portion.
[0008] The invention further resides in a metallic crown closure including a centre panel,
and a peripheral skirt portion depending downwardly therefrom, the distal end of the
skirt portion being curled outwardly to form a curl portion, the curl portion comprising
more than 360° of material when viewed in cross section. The metallic crown closure
is conveniently formed of aluminium, steel, or of metal coated with a polymer material.
[0009] The invention provides a crown closure with a distinctive appearance, and significant
functional advantages. For example, the curled skirt has several advantages over the
conventional corrugated skirt, not least in that it provides less of a safety hazard
if discarded inappropriately. Furthermore, the uncurled corrugated crown closures
are prone to a problem known as 'dusting', in which closures contact each other during
transit and the sharp edges of the crown closures chip off small particles of coating
materials, producing dust particles which can cause contamination. The curled periphery
of the crown closures of the present invention help to avoid this problem.
[0010] It is conceivable that the use of a curled portion which on application is moved
under the capping bead, may allow the use of thinner material. The curl adds strength
to the closure, giving an opportunity for lightweighting. Another possible advantage
is that, by providing a relatively plain skirt portion as opposed to the corrugated
skirts used previously, the skirt portion may be used for printing decorative or promotional
material.
[0011] The invention will now be further described by way of example only, with reference
to the accompanying drawings, in which:-
Fig.1 is a schematic sectional view of capping apparatus for carrying out the method
of the present invention, shown in a first position;
Fig.2 is a schematic sectional view of the apparatus of Fig.1, shown in a second position;
Fig.3 is an enlarged view of a part of Fig.1;
Fig.4 is an enlarged view of a part of Fig.2;
Fig.5 is a schematic sectional view of apparatus for carrying out an alternative embodiment
of the invention;
Fig.6 is a perspective view of a capping tool for use in the apparatus of Fig.5;
Fig.7 is a schematic sectional view of the apparatus of Fig.5, shown in a second position;
Fig.8 is a perspective view of a crown closure affixed to a bottle using the apparatus
of Figs.5 - 7;
Fig.9 is a schematic sectional view of an alternative embodiment of the crown closure
for use in accordance with the apparatus of Figs. 1 to 4; and
Fig.10 is a schematic sectional view of the closure of Fig.9, shown after it has been
sealed on to a bottle.
[0012] Referring to Fig.1, capping apparatus shown generally at 1 comprises a capping tool
2 reciprocal on a central shaft 3. The capping tool is generally cup shaped and comprises
a cylindrical sidewall 4 depending from an upper end 5. A central hole 6 allows the
shaft 3 to pass therethrough. The lower end of the tool is open, the opening 7 being
provided with a tapered infeed section 8. The shaft 3 has a piston plate 9 at the
lower end thereof and a spring 10 is constrained between the piston plate and the
upper end 5 of the tool.
[0013] A bottle shown generally at 11 is presented to the apparatus 1, with a crown closure
12 placed thereon. The crown closure comprises a centre panel 13 and a peripheral
skirt 14 depending therefrom. The skirt 14 terminates in an outer curl 15 which, as
shown in Fig.3, comprises a complete curl including at least 360° of material. A gasket
of sealing compound 16, typically a plastisol material, is attached to the underside
of the centre panel between the panel and an annular top surface 17 of the bottle.
The bottle also includes an annular capping bead 18, and the outer curl 15 lies adjacent
the capping bead 18.
[0014] To attach the crown closure 12 to the bottle 11, the piston plate 9 holds the closure
in position, and the capping tool 2 is lowered on the central shaft from the position
shown in Figs.1 and 3 to that shown in Figs. 2 and 4. As the capping tool 2 is lowered,
the tapered infeed section 8 progressively contacts the outer curl 15, moving it downwardly
and inwardly to the position shown in Fig.4, in which it lies under the capping bead
18. During this movement the outer curl 15 is partially uncurled, but remains curled
to the extent that at least 270° of material is contained within the curl. In this
way the crown closure 12 is attached to the bottle 11 having a distinctive slimline
appearance. Furthermore, the cut edge 19 of the closure is hidden so as not to pose
a danger to users, and yet it is also maintained in a position away from the surface
of the bottle so that if rust starts to form on the cut edge 19, it is not in contact
with the bottle 11.
[0015] Figs.5 to 7 show an alternative embodiment of apparatus in which features similar
to those in Figs. 1 to 4 are designated with like reference numerals. The apparatus
is suitable for capping crown closures 12 in which the outer curl 15 is provided with
substantially more than one turn of material, in this case approximately 1½ turns
of metal. The capping tool 2 differs from that described previously in that the tapered
infeed section 8 is castellated, and has inwardly extending segments 20 separated
by land portions 21. This tool is shown in Fig.6.
[0016] The operation of the apparatus is similar to that previously described, with the
capping tool 2 being lowered on the central shaft 3 as shown in Fig.7. The segments
20 contact the outer curl 15 so as to urge it under the capping bead 18 at those positions
around its circumference in which contact is made. The result is the petaloid structure
of Fig.8, in which reformed areas 22 alternate with plain areas 23 around the circumference
of the skirt 14.
[0017] In both of the above embodiments, the crown closure 12 may be removed from the bottle
11 using a conventional bottle opener. In the arrangement of Fig.8, the plain areas
23 provide particularly good sites on which the bottle opener can be employed.
[0018] Figs. 9 & 10 show an alternative crown closure having a centre panel 13, peripheral
skirt 14 and sealing compound 16 etc. as previously described. In the closure of Figs.
9 & 10, however, the skirt 14 is flared outwardly and the curl at the end thereof
is an inwardly facing curl 24. The closure 12 is placed on a bottle 11 as before,
and presented to apparatus as previously described with reference to Figs. 1 to 4.
The capping tool moves downwardly reforming the skirt 14 into the position shown in
Fig.10, in which the inner curl 24 is rolled under the capping bead 18 on the bottle
11, securing the crown closure on to the bottle as previously described.
1. A method of capping a bottle comprising the steps of:
i) providing a metallic crown closure including a centre panel, and a peripheral skirt
portion depending downwardly therefrom, the distal end of the skirt portion being
curled to form a curl portion;
ii) locating the crown closure over the neck of a bottle, the neck of the bottle including
an outwardly extending capping bead; and
iii) reforming of the crown closure to move at least a part of the curl portion under
the capping bead, thereby securing the crown closure onto the neck of the bottle.
2. A method according to claim 1, characterised in that the crown closure is provided with an outwardly facing curl portion.
3. A method according to claim 1 or claim 2, characterised in that the crown closure is provided with a curl portion comprising more than 360° of material
when viewed in cross section.
4. A method according to any of claims 1 to 3, characterised in that the reforming step acts to roll the curl portion downwardly with respect to the centre
panel.
5. A method according to claim 4, characterised in that the reforming step acts to tighten the curl portion as it is moved.
6. A method according to claim 4 or claim 5, characterised in that the reforming step acts to roll the curl portion such that there is still more than
270° of material when viewed in cross section, after the curl portion has been moved
under the capping bead.
7. A method according to any preceding claim, characterised in that the reforming step moves the entire curl portion under the capping bead.
8. A method according to claim 7, characterised in that the reforming step comprises contacting the curl portion with an annular tool having
a tapered infeed portion, and moving the annular tool downwardly to move the curl
portion under the capping bead on the bottle.
9. A method according to any of claims 1 to 6, characterised in that the reforming step comprises contacting the curl portion with a tool having a plurality
of projections thereon, and moving the projections with respect to the curl portion
so as to form a fluted arrangement in which a plurality of sections of the curl portion
are moved under the capping bead of the bottle.
10. A metallic crown closure for use in the method of any of claims 1 to 9.
11. A metallic crown closure including a centre panel, and a peripheral skirt portion
depending downwardly therefrom, the distal end of the skirt portion being curled to
form a curl portion, the curl portion comprising more than 360° of material when viewed
in cross section.
12. A metallic crown closure according to claim 11, characterised in that the curl portion is an outwardly facing curl portion.
13. A metallic crown closure according to claim 11 or 12, characterised in that it is formed of aluminium.
14. A metallic crown closure according to claim 11 or 12, characterised in that it is formed of steel.
15. A metallic crown closure according to claim 13 or claim 14, characterised in that it is formed of metal coated with a polymer material.