[0001] This invention concerns a container finish, a container with a container finish and
a combination of a container finish and a closure cap according to the preamble to
the independent patent claims.
[0002] In the case of containers that are filled with beverages containing carbon dioxide,
the internal pressure will be raised when such a container is in the closed condition.
Upon opening the container, sudden ejection of the closure due to the raised internal
pressure should be avoided. Such ejection is accompanied by a risk of injury to the
consumer.
[0003] Thus usually containers or closures are provided with means to vent the closure during
unscrewing, allowing a venting time that lasts long enough to prevent an intentionally
rapid unscrewing and the risk of a high-speed ejection of closures.
[0004] In order to facilitate opening, short opening angles are preferred.
[0005] Various closure arrangements with multi-start threads on the closure and the container
finish are state of the art for such purpose. With short opening angles, the opening
time until full release of the closure is reduced and the venting capacity thus needs
to be increased.
[0006] WO 97/28057, for example, discloses a closure that possesses a twin-start thread. Two outwardly
protruding threads are displaced by 180 DEG. Each thread preferably extends over an
angle of 240 DEG to less than 360 DEG.
[0007] The distribution of the force exerted from the container finish onto a closure is,
with such an arrangement, point-symmetrical and diagonally opposed so that the risk
of tilting or one-sided ejection is reduced.
[0008] Recently there has been an increased demand for short and lightweight finishes.
US 7,866,496 discloses a finish for a hot fill container with a weight from about 3.5 to 8 g.
US 4,242,398 concerns a pressure resistant thermoplastic container, wherein in order to reduce
the centre of gravity the material or wall thickness in the neck and shoulder region
is redistributed to the lower portion of the container. Whereas a typical upper neck
or finish weighs about six grams, a lightweight finish weighs as low as two grams.
Short finishes are also known for non carbonated beverages.
[0009] The object of the invention is to avoid drawbacks of the state of the art, and in
particular to create a short lightweight container finish and a combination of container
finish and a short closure cap which nevertheless possesses venting properties for
reduction of the internal pressure during the opening sequence of containers containing
beverages with a carbon dioxide content.
[0010] According to the invention, these and other objects are solved with a closure finish
and a combination of a closure cap and a container finish according to the independent
patent claims.
[0011] A container finish according to the present inventions possesses an essentially cylindrical
outside surface with one single thread. All parts of the single thread are arranged
on one virtual continuous screw line which has no kink and no step.
[0012] The thread is arranged on the outside surface so as to extend over an angle less
than 550 DEG and more than 360 DEG. During opening, such an arrangement prevents tilting
or one-sided opening of the closure, and its ejection from the finish, since the force
exerted from the container finish onto a closure is evenly distributed around the
whole circumference of the finish. Thus the risk of premature and one-sided ejection
is reduced. On the other hand the opening angle is still small ' enough for providing
a quick and comfortable opening.
[0013] The container finish according to the present invention further comprises at least
one venting recess, said venting recess interrupting the thread. During the opening
sequence, the venting recess permits reduction of the internal pressure within the
container at a time when a closure is still firmly engaged with the container finish.
[0014] According to the present invention the thread has a pitch of less than 3mm, in particular
2 to 3 mm, in particular 2.5 mm.
[0015] The relatively small pitch results in a high percentage of the holding force acting
in axial direction and therefore supports the prevention of ejection. The low pitch
further allows the design of a short and thus lightweight container finish.
[0016] In a preferred embodiment of the invention at least two venting recesses are aligned
to each other, preferably in axial direction.
[0017] The alignment of the venting recesses, preferably in a vertical arrangement, results
in a "slot", which interrupts the thread twice and thus good venting behaviour is
attained. A certain lateral displacement of the superimposed "slots" is possible as
long as the free passage for exiting gas is not essentially restricted.
[0018] Preferably the venting recess has a certain circumferential aperture. The at least
one venting recess interrupts the base line of the thread over a circumferential aperture
angle around the finish axis. In a sectional top view said aperture angle is between
4 DEG and 10 DEG at the bottom of the venting recess.
[0019] Advantageously the at least one venting recess is defined by two lateral surfaces,
wherein at least one lateral surface in a radial cross section includes an angle with
respect to a radial line. In the present context a radial line is a line running from
the axis of the finish to a centre of the bottom of venting recess in a plane perpendicular
to the axis. Said angle is being between half of the aperture angle and 90 DEG in
a plane perpendicular to the axis, preferably said angle being 30 DEG or 60 DEG.
[0020] The individual venting recesses are thus formed to taper outwardly and to open from
the base line of the thread towards an outer line of the thread.
[0021] In a favourable embodiment a plurality of venting recesses or venting slots is arranged
at regular spacings in the circumferential direction, in particular six venting recesses
are arranged with a 60 DEG spacing between the radial lines.
[0022] The object of the present invention are also solved with a closure finish, preferably
as described above, wherein the container finish comprises at least one thread and
at least one venting recess. At least one venting recess has a first lateral surface.
Said first lateral surface in a radial cross section includes a first angle with respect
to the radial line. The at least one venting recess further has a second lateral surface,
said second lateral surface in a radial cross section includes a second angle with
respect to the radial line.
[0023] According to a further aspect of the present invention the first angle and the second
angle are different.
[0024] Thus the venting recess tapers outwardly and opens asymmetrically.
[0025] Preferably the first angle is equal or smaller than 30 DEG and preferably the second
angle is longer than 30 DEG, more preferably is about 60 DEG.
[0026] Preferably asymmetric venting recesses are arranged near opening lines of the mould
splits. The lateral surfaces of the venting recesses are arranged in a way that there
is no undercut in the moving direction of the mould splits. Thus the asymmetric openings
enable an easy de-moulding of the container finish, especially in the region of a
venting recess.
[0027] Particularly the container finish is formed in a mould with two parts forming the
outer surface of the finish. Thus there is a single parting line for de-moulding.
The lateral surfaces of a venting recess shall be parallel to or taper outwardly from
the moving direction, thus in a direction perpendicular to the parting line. This
is achieved by asymmetrically arranged lateral surfaces for venting recesses close
to the parting line.
[0028] According to a further aspect of the present invention the thread comprises a truncated
thread end, preferably a basi-cally horizontal surface on the lower side of the thread
end.
[0029] The shorter the distance between the lower container thread end and a retaining bead
for retaining a tamper.evident strip of a closure, the shorter the distance that can
be selected between the lower thread end of the closure and an anti-tamper strip on
the closure. A longer distance between the lower container thread and the retaining
bead leads to a longer passage of the gas. The exiting gas thus will be subject to
higher resistance. By selecting a longer distance a worsened gas-release behaviour
results.
[0030] In order to allow the thread to pass into the fully screwed on position, even with
a small distance between lower thread end and retaining bead, the lower side of the
thread end is truncated. Preferably the lower side of the thread end is flattened,
thus the thread end has a smaller axial extension than the rest of the thread.
[0031] The truncation typically extends over the first tread segment.
[0032] Preferably the axial distance between the lower side of the thread end and the upper
side of the retaining bead is smaller than the distance between the upper side of
the thread and the lower side of the thread part which is axially above.
[0033] Hence the thread engagement between closure and neck finish is maximized with at
the same time allowing an appropriate venting time when the closure gets unscrewed.
[0034] In a beneficial embodiment the finish has a weight of 2.0 g - 2.1 g, in particular
2.05g.
[0035] The container finish comprises a cylindrical wall with a thickness of about 2-2.5mm
and is preferably made from PET.
[0036] In a preferred embodiment the container finish beneath the threads, possesses a circumferential
retaining bead for an anti-tamper strip of a closure cap. Said bead protrudes radially
outwards, in particular more than the thread, in particular more than 1.25 times the
radial extension of the thread.
[0037] When capping the container finish the anti-tamper strip may easily pass the thread
and only bulge when passing the raining bead.
[0038] Preferably the retaining bead has an axial extension which is smaller that the axial
extension of the thread, in particular less than 70% of the axial extension of the
thread.
[0039] The closure is held on the container by the threads. The threads therefore need to
withstand high axial forces due to internal pressure. Depending on the frangible connection
between the main part of the closure cap and the taper evident strip the retaining
bead being responsible for breaking this connection needs not to be as strong as the
thread.
[0040] The objects of the present invention are also solved with a container finish, preferably
as described above, which has at least one thread and a circumferential retaining
bead for an anti-tamper strip, said bead protruding radially outwards. At least a
part of the upper side of the retaining bead in an axial cross section includes an
angle of less than 10 DEG, in particular 5 DEG to 10 DEG, more particularly 8 DEG,
with a plane perpendicular to the axis.
[0041] Preferably, the lower side of the sealing bead is basically horizontal. The angle
between the lower side of the retaining bead and a plane perpendicular to the axis
may deviate up to 3 DEG, is preferably 2 DEG.
[0042] A small angle between the upper side and the lower side of the retaining bead provides
for a flat retaining bead.
[0043] In a favourable embodiment the upper side of the retaining bead comprises a radially
inner part arranged close to the essentially cylindrical outside surface of the finish
and an outer part arranged adjacent and exterior with respect to the inner part of
the upper side. In an axial cross section the inner part and the outer part have different
angles to a plane perpendicular to the axis.
[0044] Whereas the inclination of the inner part defines the axial extension of the retaining
bead, the radially outer part provides a sliding face for the tamper evident strip
passing the retaining band.
[0045] Preferably the outer part of the upper side in an axial cross section includes an
angle of 35 DEG - 45 DEG, in particular 40 DEG, with a plane perpendicular to the
axis.
[0046] It turned out that this angle being arranged only on the outer part of the retaining
bead is suitable to allow the tamper evident strip passing the retaining bead without
breaking the frangible connection.
[0047] Advantageously the ratio between the radial lengths of the inner part of the upper
side and the radial length of the outer part of the upper side is between 1:1 and
2:1.
[0048] The basic shape of the retaining bead is determined by the inclination of the inner
part of the upper side. Since the inner part of the surface includes a small angle
with the plane perpendicular to the axis, the retaining bead has a small axial extension
and has a flat appearance.
[0049] The finish comprises a total axial height extending from the underside of a transfer
ring to the upper open end and an axial closing height extending from the underside
of the retaining bead to the upper open end. Preferably, the ratio between the total
axial height and the axial closing height is between 1.5:1 and 1.75:1.
[0050] Preferably the total axial height is 12 mm and the axial closing height is 7.4 mm.
These measures correspond to measures for finishes of containers for non carbonated
products. Finishes for non carbonated beverages usually have a more simple form since
there is no need for closing forces suitable to withstand internal pressure or for
venting properties.
[0051] Thus the finish may be run on the same swing lines which are also used for bottling
non carbonated beverages without considering huge handling equipment changeover.
[0052] A further aspect of the invention concerns a container with a container finish as
described above.
[0053] A further aspect of the invention concerns in combination, a container finish as
described above and a closure cap. The closure cap comprises a top panel, a cylindrical
skirt depending from the periphery of the top panel, said skirt possessing an essentially
cylindrical inside surface with at least one thread protruding radially inwards.
[0054] Beneficially the closure cap comprises a tamper indicating band, frangibly connected
to the open end of the skirt.
[0055] The tamper indicating band has a locking element with a retaining surface, which
abuts against the lower surface of the retaining bead of the closure finish when the
closure cap is applied to the container and opened for the first time.
[0056] Preferably the thread start of the closure, located at the bottom end of the closure
skirt has a truncated thread profile, in order to allow proper passage along the truncated
thread end of the closure finish. Preferably the lower side of the thread start of
the closure is flattened. Thus the thread start of the closure has a smaller axial
extension than the rest of the thread and matches with the upper side of the retaining
bead.
[0057] With a truncated thread an optimal closing is provided whereas the de-moulding constraints
are as low as possible.
[0058] The invention will now be further described and illustrated by way of the following
description of preferred embodiments with reference to the accompanying drawings,
in which
- Figure 1
- is a first side view of a container finish;
- Figure 2
- is a second side view of the container finish;
- Figure 3
- is a sectional view of a part of the container finish;
- Figure 4
- is a top view of the container finish;
- Figure 5
- is a sectional view of a combination of a closure finish and a closure cap.
[0059] Figure 1 is a first side view of a container finish 1 according to the present invention.
[0060] The container finish 1 has an essentially cylindrical outside surface 2 with one
single thread 3.
[0061] The container finish 1 comprises several venting recesses 4, said venting recesses
4 interrupting the thread 3. Some venting recesses 4 are axially aligned and form
a venting slot 5.
[0062] In this embodiment the thread 3 has a pitch 6 of 2.5 mm.
[0063] The container finish 1 possesses a circumferential retaining bead 7 for an anti-tamper
strip, said bead protruding radially outwards.
[0064] The container finish 1 further comprises a transfer ring 8 also protruding radially
outwards.
[0065] The total axial height 9 extending from the underside 10 of the transfer ring 8 to
the upper open end 11 is 12mm. The axial closing height 12 extending from the underside
13 of the retaining bead 7 to the upper open end 11 is 7.4mm. Thus the ratio between
the total axial height 9 and the axial closing height 12 is about 1.5:1.
[0066] The typical inner diameter of the finish 1 is 21.74mm, the maximal outer diameter
including the transfer ring 8 is 29.25mm. Thus the finish 1 is compatible to standard
bottling lines.
[0067] Figure 2 is a second side view of the container finish 1.
[0068] The thread 3 comprises a horizontal truncated thread end 16, a flattened surface
14 on the lower side 15 of the thread end 16. The truncation typically extends over
the first thread segment.
[0069] The retaining bead 7 has an axial extension 17 which is smaller that the axial extension
18 of the thread 3.
[0070] Figure 3 is a sectional view of a part of the container finish 1.
[0071] The upper side 19 of the retaining bead 7 comprises a radially inner part 21 arranged
close to the essentially cylindrical outside surface 2 of the finish 1 and an outer
part 22 arranged adjacent and exterior with respect to the inner part 21 of the upper
side 19.
[0072] The inner part 21 of the upper side 19 of the retaining bead 7 includes an angle
20 of 6 DEG, with a plane perpendicular to the axis of the finish.
[0073] The inner part 21 and the outer part 22 in an axial cross section include different
angles with the lower side 13 of the retaining bead 7.
[0074] The outer part 22 includes an angle 23 of 40 DEG, with plane perpendicular to the
axis.
[0075] The ratio between the radial lengths 24 of the inner part 21 and the radial length
25 of the outer part 22 is 1.5:1.
[0076] Figure 4 is a top view of the container finish 1.
[0077] The thread 3 is arranged on the outside surface 2 so as to extend over an angle 26
of 500 DEG.
[0078] The venting slots 5 are arranged at regular circumferential spacings 27 of 60 DEG.
[0079] The venting recesses 4 interrupt the thread 3 over an aperture angle 28 around the
outside surface 2. The aperture angle 28 is 10 DEG at the bottom 29 of the recess
4.
[0080] A first venting recess 104 is delimited by two lateral surfaces 30.
[0081] The lateral surfaces 30 include an angle 32 with respect to the radial line 33 connecting
the centre 34 of the finish 1 and the centre 35 at the bottom of the venting recess
4 of 30 DEG.
[0082] A further venting recess 204 has a first lateral surface 230, including in a radial
cross section a first angle 236 with respect to the radial line 233.
[0083] The venting recess 204 has a second lateral surface 231, including a second angle
237 with respect to the radial line 233.
[0084] The first angle 236 and second angle 237 are different: The first angle 236 is 30
DEG and the second angle is 60 DEG.
[0085] Asymmetric venting recesses 204 are arranged close to the parting line 38 of the
moulding tool (not shown in the figure), whereas symmetric venting recesses 104 are
arranged perpendicular to the parting line. The orientation of the lateral surfaces
30, 230, 231 pointing away from the parting lines facilitates the de-moulding.
[0086] Figure 5 is a sectional view of a combination of a closure finish 1 and a closure
cap 40 comprising a top panel 41, a cylindrical skirt 42 depending from the periphery
of the top panel 41. The skirt 42 possesses an essentially cylindrical inside surface
with at least one thread 43 protruding radially inwards and a tamper indicating band
44, frangibly connected to the open end 45 of the skirt 42 (bridges are not explicitly
shown in this sectional view).
[0087] The thread 3 of the finish comprises a horizontal truncated thread end 16. A flattened
surface 14 is arranged on the lower side 15 of the thread end 16. The flattened surface
provides more axial space between the lower side 15 of the thread end 16 and the retaining
bead 7.
[0088] Correspondingly the thread start 46 of the closure cap 40 which is located near the
open end 45 of the skirt 42 is also truncated. The thread start 46 has a flattened
surface 47 on its lower side 48. Thus the thread start 46 as a smaller axial extension
than the rest of the thread 43. The thread start 46 may be located in the axial gap
between the thread end 16 of the closure finish and the retaining bead 7. The lower
side 48 of the thread start matches with the upper side of the retainer bead 7.
[0089] Hence the closure cap 40 may be brought to the fully screwed on position.
1. In combination:
a container finish (1) with an essentially cylindrical outside surface (2) with one
single thread (3), said thread (3) being arranged on the outside surface (2) so as
to extend over an angle of less than 550 DEG and more than 360 DEG, the container
finish comprising at least one venting recess, said venting recess (4; 104, 204) interrupting
the thread (3), wherein the thread (3) has a pitch (6) of less than 3 mm, in particular
2 to 3 mm, in particular 2.5mm; and
a closure cap (40) comprising a top panel (41), a cylindrical skirt (42) depending
from the periphery of the top panel (41), said skirt (42) possessing an essentially
cylindrical inside surface with at least one thread (43) protruding radially inwards
and a tamper indicating band (44), frangibly connected to the open end (45) of the
skirt (42).
2. A combination according to Claim 1, wherein at least two venting recesses (4; 104,
204) of the container finish (1) are aligned in an axial direction.
3. A combination according to claim 1 or 2, wherein the at least one venting recess (4;
104, 204) of the container finish (1) interrupts the thread (3) over an aperture angle
(28) around the outside surface (2), said aperture angle being between 4 DEG and 10
DEG at the bottom (29) of the recess (4; 104, 204).
4. A combination according to Claim 3 wherein the at least one venting recess (4; 104,
204) of the container finish (1) has two lateral surfaces (30, 230, 231), wherein
at least one lateral surface (30, 230, 231) in a radial cross section includes an
angle (32, 236, 237) with respect to a radial line (33, 233), said angle (32, 236,
237) being between half of the aperture angle (28) and 90 DEG, preferably said angle
(32, 236, 237) being 30 DEG or 60 DEG.
5. A combination according to at least one of the preceding claims, characterized in that a plurality of venting recesses (4; 104, 204) of the container finish (1) are arranged
at regular spacings (27) in the circumferential direction, in particular six venting
recesses (4; 104, 204) with a 60 DEG spacing.
6. A combination according to claim 3, 4 or 5, the container finish comprising one thread
(3) and at least one venting recess (4; 104, 204), at least one venting access (204)
having a first lateral surface (230), said first lateral surface (230) in a radial
cross section including a first angle (236) with respect to a redial line (233), the
at least one venting recess (204) having a second lateral surface (231), said second
lateral surface (231) in a radial cross section including a second angle (237) with
respect to the redial line (233), wherein the first angle (216) and second angle (237)
are different, preferably the first angle (236) is equal or smaller than 30 DEG end
preferably the second angle (237) is greater than 30 DEG, more preferably 60 DEG.
7. A combination preferably according to at least one of the preceding claims, the container
finish comprising a thread (3) and, preferably, a circumferential retaining bead (7)
for an anti-tamper strip, said bead protruding radially outwards, characterised in that the thread (3) comprises a truncated thread end (14), preferably a horizontally truncated
surface (14) on the lower side (15) of the thread end (16).
8. A combination according to at least one of the preceding claims characterised in that the finish (1) has a weight of 2.0g - 2.1g, in particular 2.05g.
9. A combination according to at least one of the preceding claims, characterized in that container finish (1) beneath the thread (3), possesses a circumferential retaining
bead (7) for an anti-tamper strip, said bead (7) protruding radially outwards, in
particular more than the thread (3), in particular more than 1.25 times the radial
extension of the thread (3).
10. A combination according to Claim 9, characterized in that the retaining bead (7) of the container finish (1) has an axial extension (17) which
is smaller than the axial extension (18) of the thread (3), in particular less than
70% of the axial extension (18) of the thread (3).
11. A combination according to claim 9 or claim 10, the container finish comprising one
thread (3) and a circumferential retaining bead (7) for an antitamper strip, said
bead protruding radially
outwards, wherein at least a part of the upper side (19) of the retaining bead (7)
in an axial cross section includes an angle (20) of less than 10 DEG, in particular
5 DEG to 10 DEG, more particularly 6 DEG, with a plane perpendicular to the axis of
the finish.
12. A combination according to claim 9, 10 or 11, characterized in that the upper side (19) of the
retaining bead (7) of the container finish (1) comprises a radially inner part (21)
arranged close to the essentially cylindrical outside surface (2) of the finish (1)
and an outer part (22) arranged adjacent and exterior with respect to the inner part
(21) of the upper side (19), the inner part (21) and the outer part in an axial cross
section including different angles (20,23) with a plane perpendicular to the axis
of the finish.
13. A combination according to Claim 12, characterized in that the outer part (22) of the upper side (19) of the container finish (1) in an axial
cross section includes an angle (23) of 35 DEG - 45 DEG, in particular 40 DEG, with
a plane perpendicular to the axis of the finish.
14. A combination according to claims 12 or 13, characterized in that the ratio between the radial lengths (24) of the inner part (21) of the upper side
(19) and the radial length (25) of the outer part (22) of the upper side (19) of the
container finish (1) is between 1:1 and 2:1.
15. A combination according to at least one of the claims 9-14, characterized in that the finish (1) comprises a total axial height (9) extending from the underside (10)
of a transfer ring (8) to the upper open end (11) and an axial closing height (12)
extending from the underside (13) of the retainer bead (7) to the upper open end (11),
wherein the ratio between the total axial height (9) and the axial closing height
(12) is between 1.5:1 and 1.75:1.
16. Container with a container finish (1) with an essentially cylindrical outside surface
(2) with one single thread (3), said thread (3) being arranged on the outside surface
(2) so as to extend over an angle of less than 550 DEG and more than 360 DEG, the
container finish comprising at least one venting recess, said venting recess (4; 104,
204) interrupting the thread (3), wherein the thread (3) has a pitch (6) of less than
3 mm, in particular 2 to 3 mm, in particular 2.5mm.
17. A combination according to Claim 1, characterized in that the at least one thread (43) protruding radially inward from the cylindrical inside
of the cylindrical skirt (43) of the closure cap (40) is designed to match with the
lower end (16) of the thread (3) of the container finish (1) in a closed position
preferably with a truncated thread end on the lower side (15) of the thread end (16),
more preferably the at least one closure thread (43) comprises a truncated thread
start (46) on the upper and/or lower side (48).
18. A closure cap (40) comprising a top panel (41), a cylindrical skirt (42) depending
from the periphery of the top panel (41), said skirt (42) possessing an essentially
cylindrical inside surface with at least one thread (43) protruding radially inwards
and a tamper indicating band (44), frangibly connected to the open end (45) of the
skirt (42), characterised in that a thread start (46) of the cap (40) located at the bottom end of the closure skirt
(42) has a truncated thread profile.
19. A closure cap (40) as claimed in claim 18, characterised in the thread start (46) has a flattened surface (47) on its lower side (48).
20. A closure cap (40) as claimed in claim 18 or 19, characterised in that the thread start (46) has a smaller axial extension that the rest of the thread (43).