U.S. patent application number 11/571401 was filed with the patent office on 2008-04-10 for method for peeling off or separating a sealing film sealed onto the rim of the neck of a bottle or the like and screw cap for carrying out said method.
Invention is credited to Rainer Ammann.
Application Number | 20080083694 11/571401 |
Document ID | / |
Family ID | 35044761 |
Filed Date | 2008-04-10 |
United States Patent
Application |
20080083694 |
Kind Code |
A1 |
Ammann; Rainer |
April 10, 2008 |
Method For Peeling Off Or Separating A Sealing Film Sealed Onto The
Rim Of The Neck Of A Bottle Or The Like And Screw Cap For Carrying
Out Said Method
Abstract
In a method for the at least partial detachment or separation of
a sealing film or foil 14 that is sealingly attached to a rim 11 of
a neck 3 of a container, vessel, bottle 1, or the like, which rim
11 has a circular sealing surface 12 and the neck 3 has a male
thread 4 and a center axis 5, and a screw cap 7 having a female
thread 6 complementary to said male thread 4 is screwed down onto
the male thread 4 of the sealed neck 3 whilst the screw cap 7 can
be unscrewed at any later point in time, as desired, when the screw
cap 7 is unscrewed from the neck 3, said sealing film 14 is at
least partially detached from said rim 11 of the neck 3, radially,
starting from the periphery of the rim and progressing inwardly
toward the center axis 5, to be subsequently lifted off from said
rim 11.
Inventors: |
Ammann; Rainer; (Bobingen,
DE) |
Correspondence
Address: |
BROOKS KUSHMAN P.C.
1000 TOWN CENTER, TWENTY-SECOND FLOOR
SOUTHFIELD
MI
48075
US
|
Family ID: |
35044761 |
Appl. No.: |
11/571401 |
Filed: |
June 30, 2005 |
PCT Filed: |
June 30, 2005 |
PCT NO: |
PCT/EP05/07056 |
371 Date: |
December 28, 2006 |
Current U.S.
Class: |
215/316 |
Current CPC
Class: |
B65D 2251/0015 20130101;
B65D 2251/0093 20130101; B65D 51/228 20130101 |
Class at
Publication: |
215/316 |
International
Class: |
B65D 41/00 20060101
B65D041/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 1, 2004 |
DE |
10 2004 032 100.0 |
Claims
1. A method for the at least partial detachment or separation of a
sealing film or foil that is sealingly attached to a rim of a neck
of a container, vessel, bottle, or the like, which rim has a
circular sealing surface and the neck has a male thread and a
center axis, and a screw cap having a female thread complementary
to said male thread is screwed down onto the male thread of the
sealed neck while the screw cap can be unscrewed at any later point
in time, as desired, characterized in that when the screw cap is
unscrewed from the neck, said sealing film is at least partially
detached from said rim of the neck, radially, starting from the
periphery of the rim and progressing inwardly toward the center
axis, to be subsequently lifted off from said rim.
2. A method as defined in claim 1, characterized in that prior to
the initial screwing of the screw cap onto the male thread of the
neck, a reinforcement disk coated on one side with an adhesive is
inserted into the screw cap and, when the cap is subsequently
screwed onto the neck, said disk will be pressed with its adhesive
against the sealing film that is sealingly attached to the rim of
the neck, while a surface-to-surface bonding of the reinforcement
disk with the sealing film is achieved after the cap has been
screwed down.
3. A method as defined in claim 2, characterized in that induction
welding is used for surface-to-surface bonding of the reinforcement
disk to the sealing film, a thermoplastic compound being used as
adhesive.
4. A method as defined in claim 1, characterized in that
reinforcement of the sealing film has been achieved by using a
sealing film which has already been reinforced by a
surface-to-surface bonded reinforcement disk, or a sealing film
that has been stiffened or is resistant to bending.
5. A method as defined in claim 1, characterized in that a glue,
lamination, or sealing wax composed of substantially PE, PET,
polyester, or polystyrene, or a combination of these substances,
may be used as an adhesive on the surface of the reinforcement disk
facing the sealing film.
6. A screw cap for the implementation of the method as defined in
claim 1, comprising a top section and also a sleeve section having
an female thread and an open end to enable screwing of the cap
onto, and unscrewing thereof from, a male thread of a neck having a
rim of a bottle or the like, which neck is hermetically sealed by a
sealing film which has a radially overlapping circumferential zone
and which is sealingly attached to a circular sealing surface of
the rim of the neck, and which is capable of being detached and/or
destroyed in order to expose the contents of a bottle,
characterized in that it has at least one detachment knife disposed
on the sleeve section between the female thread and the top section
and along the inside periphery of the sleeve section, which knife,
in its starting position prior to being screwed down, extends
obliquely toward the open end of the screw cap and inwardly toward
the center axis of the neck or of the screw cap, wherein the
distance of the detachment knife from the center axis prior to
screwing down is less than the outside diameter (D) of the rim of
the neck, which detachment knife is resiliently displaced as the
screw cap is screwed down onto the neck of the bottle, and, due to
the pressure imposed by the rim of the neck and the circumferential
zone of the sealing film the detachment knife with its knife edge
resiliently bends upwardly and comes to rest on the outer periphery
of the neck above the male thread and beneath the
radially-overlapping circumferential zone of the sealing film, and
is resiliently deformed and resiliently pre-stressed toward the
center axis once the cap is screwed down, further characterized in
that, when the cap is unscrewed, the knife edge of the detachment
knife is disposed initially obliquely in relation to the sealing
film and toward the center axis, and then, due to its resiliency by
springing back, continuously penetrates further radially inwardly
toward the center axis between the overlapping circumferential zone
of the sealing film and the rim of the neck of the bottle, wherein
the sealing film is adapted to be progressively separated from the
rim of the bottle toward the center axis and to be stored in the
screw cap between the detachment knife and the top section.
7. A screw cap as defined in claim 6, characterized in that a
plurality of individual detachment knives is fixed to the sleeve
section and distributed around the inside periphery of the sleeve
section in the circumferential or rotational direction (A), which
knives, being disposed radially about the center axis in a common
plane, leave a clearance (W) in the zone of the center axis which
has a smaller diameter than that of the circular sealing surface of
the rim of the neck of the bottle or the like.
8. A screw cap as defined in claim 6, characterized in that each
individual detachment knife has a knife edge that partially extends
in the unscrewing direction (A) or a component thereof pointing in
said unscrewing direction (A).
9. A screw cap as defined in claim 8, characterized in that each
knife edge of the detachment knife is concavely curved and has a
radially projecting, pointed cutting projection trailing in the
rotational unscrewing direction (A).
10. A screw cap as defined in claim 6, characterized in that at
least one circular pressure lip is formed on the inside surface of
the top section of the screw cap, disposed about the center axis
opposite to the circumferential zone of the sealing film with its
reinforcement disk, if present, which lip presses the
circumferential zone of the sealing film and the reinforcement
disk, if present, onto the rim of the neck and nestles thereon as
the screw cap is screwed down.
11. A screw cap as defined in claim 6, characterized in that the
detachment knife is configured to extend around the inside
periphery of the sleeve section in the form of an annular
knife.
12. A method for the at least partial detachment or separation of a
sealing film or foil that is sealingly attached to a rim of a neck
of a container, vessel, bottle, or the like, which rim has a
circular sealing surface and the neck has an male thread and a
center axis, and a screw cap having a female thread complementary
to the male thread and capable of being screwed down onto the male
thread of the sealed neck unscrewed at any later point in time, as
desired, characterized in that an intermediate layer of a
thermoplastic compound, glue, and/or a sealing wax is introduced
between the top section and the neck before the screw cap is
screwed down onto the neck of the container or the like, the
intermediate layer being pressed onto the sealing film by the
inside surface of the top section as the screw cap is screwed down
onto the neck of the container, and the inside surface is glued or
welded to the surface of the sealing film in such a way that the
sealing film firmly adheres to the inside surface and the sealing
film is at least partially entrained by the screw cap when the
latter is unscrewed from the neck of the container or bottle.
13. A method as defined in claim 12, characterized in that the
sealing film has, at least at certain points, embossments or
perforations configured as breaking points in the circumferential
direction within the clearance (W) of the neck, and with the aid of
the intermediate layer, the inside surface of the top section is
only glued or welded to the surface of the sealing film in the
region of the surface surrounded by said embossments or
perforations.
14. A method as defined in claim 13, characterized in that a disk
consisting of at least two layers is used as the sealing film,
wherein the layer facing the inside surface of the top section is
composed substantially of PE, PET, or aluminum and the layer facing
the neck is composed substantially of PE, PET, or sealing wax, or a
combination of the aforementioned substances.
15. A method as defined in claim 14, characterized in that only the
layer of the sealing film facing the inside surface a of the top
section is embossed or perforated, at least at certain points,
within the clearance (W) of the neck.
16. A method cap as defined in claim 13, characterized in that an
embossment or perforation forming a complete circle is used.
17. A screw cap for implementing the method as defined in claim 12,
especially one of plastics material, having a top section and a
sleeve section having a female thread and an open end for screwing
onto, and unscrewing from, a male thread of a neck with a rim of a
bottle or the like, which is hermetically sealed with a sealing
film that is sealingly attached to a circular sealing surface of
the rim of the neck, characterized in that the top section has an
inverted, anvil-like, inner, plate-like projection facing its
inside surface, so configured that the inside surface is capable of
bringing the intermediate layer to bear against the surface of the
sealing film when the screw cap is screwed down.
18. A method or screw cap as defined in claim 1, characterized in
that the vessel, container, bottle or the like used is composed of
plastics material or glass or the like.
19. A method or screw cap as defined in claim 1, characterized in
that the sealing film, especially when made of aluminum and/or
plastics material, has a circumferential zone radially overlapping
the rim of the neck.
20. A screw cap as defined in claim 1, characterized in that it is
itself composed of plastics material.
21. A screw cap as defined in claim 1, characterized in that the
degree of lift between the screw cap and the neck given by the
thread pitch and the mating of a male thread with a female thread
used is, in the fully screwed-down position of the screw cap on the
container, at least equal to the length of the detachment knife or
knives, this length in turn being at least equal to the radial
distance between the inside periphery of the sleeve section, from
which the detachment knife projects outwardly, and an imaginary
circle on the sealing surface between the sealing film and the
rim.
22. A screw cap as defined in claim 21, characterized in that the
circumference of the imaginary circle is formed by the inside
periphery of the rim of the neck.
23. A screw cap as defined in claim 21, characterized in that the
thread pitch and the thread mating are dimensioned in such a way
that each 360.degree. turn of the screw cap raises the screw cap
approximately 9 mm from the neck.
24. A screw cap as defined in claim 21, characterized in that the
female thread is configured as a triple thread.
25. A screw cap as defined in claim 21, characterized in that the
at least one detachment knife is disposed on the inside periphery
of the sleeve section above the female thread toward the top
section, and the thread path of the female thread has gaps, the
width u of which is substantially equal to, or slightly greater
than, the width of the detachment knife or detachment knives in the
circumferential direction of the inside periphery, so that when the
screw cap is removed upwardly from the mold (not shown), the at
least one detachment knife can be pressed downwardly into the gaps
and remain briefly therein until they emerge from the mold and are
exposed.
26. A screw cap as defined in claim 21, characterized in that the
detachment knife or each of the detachment knives used always has a
free end provided with a knife edge, which end is curved or bent
toward the rim when the sealing surface is penetrated between the
sealing film and the rim.
27. A screw cap as defined in claim 26, characterized in that the
free end of the at least one detachment knife is also curved on
both sides in such a way that it has a spoon-like, concave
curvature.
28. A screw cap as defined in claim 27, characterized in that a
counter-pressure lip (FIG. (16) in the form of an annulus is
provided on the inside of the top section between at least one
concentrically disposed pressure lip and the inside surface of the
sleeve section.
Description
[0001] The invention relates to a method for the at least partial
detachment or separation of a sealing film or foil that is
sealingly attached to a rim of a neck of a container, vessel,
bottle, or the like, which rim has a circular sealing surface and
the neck has an male thread and a center axis, and a screw cap
having a female thread complementary to the male thread and capable
of being screwed down onto the male thread of the neck sealed in
the aforementioned manner and the cap can be unscrewed at any later
point in time, as desired.
[0002] The invention further relates to a screw cap for the
implementation of this method.
[0003] If it is required to protect possibly sterile contents of,
say, a bottle for a prolonged period of time from outside
influences, for example from the penetration of microbes or other
contaminants, it is still necessary, as in the prior art, to apply
a sealing film that is impermeable to the aforementioned substances
to the rim of the mouth of the bottle in such a way that the actual
sealing surface also cannot be penetrated by these substances.
[0004] In general, aluminum foils that have a coating of, for
example, HDPE (high duty polyethylene) or a similar material on
their sealing side are used for standard plastics material bottles
made of, for example, polyethylene (PE) or polyethylene
terephthalate (PET). After such a sealing film is placed on the rim
of the bottle, the coating of the sealing film is welded to the rim
of the bottle. The sealing film then adheres firmly and forms an
impervious seal with the rim. Gluing rather than welding is another
option.
[0005] According to this prior art, a screw cap is screwed down to
protect the sealing film, and the user then loosens or peels off
this film by hand after unscrewing the screw cap and pulling off
any originality seal ring that may be present, on the screw cap in
order to allow access to the contents of the container. In
particular when only part of the bottle's contents have been used,
the bottle with its remaining contents can then be resealed by
screwing the screw cap back on.
[0006] With every bottle containing, say, fresh milk or juice, the
consumer finds it awkward not only to have to unscrew the screw
cap, but also to have to grasp a piece of the sealing film
projecting beyond the rim of the neck of the bottle and then to
peel off the sealing film, an operation that requires a certain
amount of dexterity.
[0007] The object forming the basis of the invention can thus be
regarded as comprising the creation of a method, and also a screw
cap for the implementation of said method, in which it is no longer
necessary to grasp the sealing film and peel it off by hand once
the screw cap has been unscrewed.
[0008] This object is achieved with a method defined above in a
first embodiment of the invention, in which, when the screw cap is
unscrewed from the bottle neck, the sealing film is at least
partially detached from the rim of the neck, radially, starting
from the periphery of the rim and progressing inwardly toward the
center axis, to be ultimately lifted off from the rim.
[0009] If appropriate, means can be provided for storing the
detached sealing film within the screw cap.
[0010] According to the invention, the process of unscrewing the
screw cap thus includes the detachment of the sealing film from the
rim of the container or the bottle and, if appropriate, subsequent
storage of the sealing film in the screw cap, which cap can then be
screwed onto, or unscrewed from, the neck in the usual manner a
number of times, as required, until the contents of the container
have been consumed due to removal thereof each time. Separate
detachment of the sealing film by hand is thus no longer
necessary.
[0011] Prior to the initial screwing of the screw cap onto the male
thread of the neck, a reinforcement disk coated on one side with an
adhesive can advantageously be inserted into the screw cap and,
when the cap is subsequently screwed onto the neck, said disk will
be pressed with its adhesive against the sealing film that is
sealingly attached to the rim of the neck, in which case a
surface-to-surface bonding of the reinforcement disk with the
sealing film is achieved after the cap has been screwed down.
Advantageous reinforcement of the generally rather thin and
flexible sealing film is thus achieved, which in turn enables the
screw top to grip the sealing film more easily.
[0012] Preference is given to the use of induction welding for
surface-to-surface bonding of the reinforcement disk to the sealing
film, a thermoplastic compound being used as adhesive.
[0013] Alternatively, reinforcement of the sealing film may be
achieved by using a sealing film which has already been reinforced
by a surface-to-surface bonded reinforcement disk, or a sealing
film that has been stiffened or is resistant to bending.
[0014] Furthermore, a glue, lamination, or sealing wax composed of,
say, PE, PET, polyester, or polystyrene, or a combination of these
substances, may be used as an adhesive on that surface of the
reinforcement disk which faces the sealing film.
[0015] A screw cap for the implementation of the method of the
invention has a top section and also a sleeve section having a
female thread and an open end to enable screwing of the cap onto,
and unscrewing thereof from, a male thread of a neck having a rim
of, say, a bottle, which is hermetically sealed by a sealing film
having a radially overlapping circumferential zone and which is
sealingly attached to a circular sealing surface of the rim of the
neck, and which is capable of being detached and/or destroyed in
order to expose the contents of the bottle.
[0016] According to the invention, the screw cap, and thus a first
device solution according to the aforementioned object, is
characterized by having at least one detachment knife disposed on
the sleeve section between the female thread and the top section
and along the inside periphery of the sleeve section, which knife,
in its starting position prior to screwing down the screw cap,
extends obliquely toward the open end of the screw cap and inwardly
toward the center axis of the neck or of the screw cap, wherein the
distance of the detachment knife from the center axis prior to
screwing down is less than the outside diameter of the rim of the
neck, which detachment knife is resiliently displaced as the screw
cap is screwed down onto the neck of the bottle, and, due to the
pressure imposed by the rim of the neck and the circumferential
zone of the sealing film, the detachment knife with its knife edge
resiliently bends upwardly and comes to rest on the outer periphery
of the neck above the male thread and beneath the radially
overlapping circumferential zone of the sealing film, and is
resiliently deformed and resiliently pre-stressed toward the center
axis when the cap is screwed down, and is further characterized in
that, when the cap is unscrewed, the knife edge of the detachment
knife is disposed initially obliquely in relation to the sealing
film and toward the center axis, and then, due to its resilience,
continuously penetrates further radially inwardly toward the center
axis between the overlapping circumferential zone of the sealing
film and the rim of the neck of the bottle, wherein the sealing
film is adapted to be progressively separated from the rim of the
bottle toward the center axis and stored in the screw cap between
the detachment knife and the top section.
[0017] As may be seen, the screw cap of the invention detaches the
sealing film that has been sealingly attached to the exposed rim of
the neck of the bottle or the like in that the detachment knife
progressively penetrates inwardly between the rim of the neck of
the bottle and the sealing film, if necessary to beyond the inside
diameter of the neck, toward the center axis of the neck, and
entrains the sealing film after detachment thereof, and the
separated sealing film is held firmly between the detachment knife
and the top section.
[0018] In a preferred embodiment, a plurality of individual
detachment knives is fixed to the sleeve section and distributed
around the inside periphery of the sleeve section in the
circumferential or rotational direction, which knives, being
disposed radially about the center axis in a common plane, leave a
clearance in the zone of the center axis which has a smaller
diameter than that of the annular region of the sealing film, or
than the outside diameter of the rim of the neck of the bottle or
the like. Depending on the properties of the adhesive used and thus
on the strength of the bond, it may be sufficient if the detachment
knife only partially severs the sealing film by its spiral cutting
action, while the remainder of the film is simply removed or torn
off on account of the tension exerted on the sealing surface of the
sealing film when the circumferential zone of the sealing film is
further raised as the cap is progressively unscrewed.
[0019] Each individual detachment knife advantageously has a knife
edge that partially extends in the unscrewing direction and that in
each case effects a spiral movement producing an inward incision at
the sealing surface between the sealing film and the rim of the
neck.
[0020] Each knife edge can advantageously be concavely curved and
have a radially projecting, pointed cutting projection trailing in
the rotational unscrewing direction, which favors penetration at
the sealing surface.
[0021] It is particularly advantageous if at least one circular
pressure lip is formed on the inside of the top section of the
screw cap, disposed about the center axis opposite to the
circumference of the sealing film with its reinforcement disk, if
present, which lip presses the circumferential zone of the sealing
film and the reinforcement disk, if present, onto the rim of the
neck and nestles thereon as the screw cap is screwed down.
[0022] This deformation of the circumference of the sealing film on
the one hand and the reinforcement disk, if present, on the other
hand also favors the penetration of the detachment knife or knives
into the space between the sealing film and the rim, because the
circumference of the sealing film and the reinforcement disk, if
present, forms a guide for the detachment knife or knives extending
obliquely toward the sealing film and toward the center axis in
such a way that the at least one detachment knife, as it slides in
between the sealing film and the rim and assumes an increasingly
horizontal detachment plane, and penetrates between the sealing
film and the rim and, if necessary, into the free space in the
clearance of the neck, can completely remove the sealing film. If
the at least one detachment knife then becomes increasingly erect
from the rim of the neck of the bottle or the like as the cap is
progressively unscrewed, it can usually return to the position that
it originally had prior to the cap being screwed down, namely
extending obliquely toward the open end and toward the center of
the cap.
[0023] If there is only one detachment knife, it can be configured
to extend around the inside periphery of the sleeve section, in
other words as an annular knife. The elasticity of the screw cap
material provides the necessary deflectability of this annular
knife toward the center axis.
[0024] However, it must be emphasized that the alignment of the at
least one detachment knife described above such that it extends in
its initial position obliquely toward the open end and inwardly
toward the center axis, of the cap, is not obligatory. In fact, the
alignment can alternatively be achieved by designing the knife
shape, on the one hand, and connecting it to the sleeve section
along the inside periphery thereof, on the other hand, such that
the at least one detachment knife extends obliquely upwardly toward
the top section and inwardly toward the center axis, of the screw
cap. In this case the at least one detachment knife already has
substantially the alignment required for the process of severing
the sealing film from the neck.
[0025] Furthermore, the aforementioned object is also achieved with
a method of the aforementioned type in a second embodiment of the
invention, wherein an intermediate layer of a glue and/or sealing
wax is introduced between the top section and the neck before the
screw cap is screwed down onto the neck of the container or the
like, the intermediate layer being pressed onto the sealing film by
the inside surface of the top section as the screw cap is screwed
down onto the neck of the container, and the inside surface is
glued or welded to the surface of the sealing film in such a way
that the sealing film firmly adheres to the inside surface and the
sealing film is at least partially entrained by the screw cap when
the latter is unscrewed from the neck of the container or the
bottle.
[0026] This entrainment occurs in the rotational direction of the
screw cap. The entrained section of the sealing film remains
affixed to the inside surface of the top section.
[0027] When the screw cap has been unscrewed, the container is thus
completely or at least partially opened so that the contents
thereof can be removed.
[0028] The sealing film advantageously has, at least at certain
points, embossments or perforations configured as breaking points
in the circumferential direction within the clearance of the neck,
and with the aid of the intermediate layer, the inside surface of
the top section is only glued or welded to the surface of the
sealing film in the region of the surface surrounded by the
embossments or perforations.
[0029] This makes it possible to tear off a central zone of the
sealing film in a controlled manner by unscrewing the screw
cap.
[0030] A disk consisting of at least two layers is advantageously
used as a sealing film, wherein the layer facing the inside surface
of the top section can be composed substantially of PE, PET, or
aluminum and the layer facing the neck can be composed
substantially of PE, PET, or sealing wax, or a combination of the
aforementioned substances.
[0031] The construction can be such that only the layer of the
sealing film facing the inside surface of the top section is
embossed or perforated, at least at certain points, within the
clearance of the neck.
[0032] Preference is given to an embossment or perforation forming
a complete circle.
[0033] A preferred screw cap for the implementation of the method
of this second embodiment of the invention and thus a second device
solution of the aforementioned object according to the invention,
especially one of plastics material, comprises a top section and a
sleeve section having a female thread and an open end for screwing
onto, and unscrewing from, a male thread of a neck with a rim of a
bottle or the like, which is hermetically sealed with a sealing
film that is sealingly attached to a circular sealing surface of
the rim of the neck, is characterized according to the invention in
that the top section has an inverted, anvil-like, inner, plate-like
projection facing its inside surface, so configured that the inside
surface is capable of being reliably positioned on the surface of
the sealing film when the screw cap is screwed down onto the neck
of the container or the like.
[0034] The vessel, container, bottle, or the like used can be
composed of glass or plastics material or the like.
[0035] Preferably, the sealing film, especially when made of
aluminum and/or plastics material, has a circumferential zone
radially overlapping the rim of the neck. The resulting
circumferential zone forms an additional guide for the detachment
knife or knives and forms, as it were, a barrier forbidding
intrusion into the top space of the screw cap, particularly when
the pressure lip, if present, is raised as the screw cap is
unscrewed to progressively expose such a circumferential zone,
against which it had formerly nestled, in such a way that the at
least one detachment knife bearing against the circumferential zone
is then guided below the circumferential zone toward the sealing
surface.
[0036] Preferably, the screw cap of the invention is made of made
of plastics material.
[0037] The invention is explained in greater detail below with
reference to the preferred exemplary embodiments illustrated in the
drawings, in which:
[0038] FIG. 1 shows a side view of a first embodiment of a screw
cap of the invention prior to placement thereof on the neck of a
bottle and prior to it being screwed down onto the neck, in a
partially cutaway side view of the screw cap and of the neck;
[0039] FIG. 2 shows a view according to FIG. 1 of a position after
starting to screw the screw cap onto the neck of the bottle in
which the knife edge of a detachment knife is just touching the
surface of the sealing film on the rim of the neck;
[0040] FIG. 3 shows the screw cap according to FIG. 2 in a middle
screwed-down position, in which the detachment knife is resting in
a substantially horizontal position on the sealing film;
[0041] FIG. 4 shows the screw cap according to FIG. 3 screwed down
beyond the middle position in which the detachment knife, however,
is not yet completely bent upwards;
[0042] FIG. 5 shows the screw cap according to the previous figures
in the final, fully tightened position, in which the detachment
knife is also in a final, erect position and a pressure lip
disposed on the inside of the top section of the screw cap has
positioned itself on the sealing film under resilient
deformation;
[0043] FIG. 6 shows a detail of FIG. 5 on an enlarged scale;
[0044] FIG. 7 shows the screw cap according to FIG. 5 after
unscrewing has commenced, in a position at which the knife edge of
the detachment knife has started to penetrate between the rim of
the container and the sealing film;
[0045] FIG. 8 shows the screw cap according to FIG. 7 after further
unscrewing, in a position in which the detachment knife has already
partially penetrated the sealing surface;
[0046] FIG. 9 shows the screw cap according to the previous figures
after further unscrewing, in a position in which the detachment
knife is in a substantially horizontal position and has already
detached the sealing film;
[0047] FIG. 10 shows the arrangement of the screw cap of the
previous figures after removal thereof from the neck of the
container, with the sealing film detached and retained in the screw
cap by the detachment knife;
[0048] FIG. 11 is a bottom view of the screw cap in the direction X
indicated by the arrow in FIG. 10;
[0049] FIG. 12 shows a screw cap according to the previous figures,
in which a reinforcement disk is being force fitted with a
plunger.
[0050] FIG. 13 shows a second embodiment of the invention with a
modified screw cap in a side view corresponding to FIG. 1;
[0051] FIG. 14 is a top view of the screw cap according to FIG. 13,
partially cut away along the line XX-XX;
[0052] FIG. 15 is a sectional drawing of the sealing film according
to FIGS. 13 and 14;
[0053] FIG. 16 is a longitudinal section of another embodiment of
the screw cap of the invention in which the turns of the female
thread have gaps in the region of the detachment knives for the
accommodation of the detachment knives during the demolding
process.
[0054] The shoulder zone 2 of a bottle 1 with a neck 3 is shown in
FIG. 1, which shoulder zone has a male thread 4 and a center axis
5. In addition, a screw cap 7 having a female thread 6 is shown,
which screw cap, like the bottle, can be made, say, of a plastics
material such as PE or PET. The screw cap 7 has a top section 8,
and a sleeve section 9 that has a female thread 6 and a open end 10
so that it is capable of being screwed down onto, and unscrewed
from, the male thread 4 on the neck 3 of the bottle 1, which neck
has a rim 11.
[0055] The neck 3 is hermetically sealed by a sealing film 14
having a radially overlapping circumferential zone 13, which is
sealingly attached to an annular sealing surface 12 (FIG. 10) of
the rim 11 of the neck 3. The sealing film 14 is capable of being
detached and/or destroyed in order to allow access to the
respective contents of the bottle.
[0056] According to the invention, at least one detachment knife 15
is provided, which knife is disposed between the female thread 6
and the top section 8 at the inside periphery 9' of the sleeve
section 9, and, in the starting position shown in FIG. 1, extends
radially and obliquely toward the open end 10 and inwardly toward
the center axis 5 and which has a knife edge 16 disposed at a
distance from the center axis 5 of the neck 3 of the bottle 1 which
is smaller than the outside diameter D of the rim 11 of the neck 3
before the cap is screwed down.
[0057] When the screw cap 7 is screwed down onto the neck 3 of the
bottle 1, it will arrive at a position, as shown in FIG. 2, at
which it is sufficiently screwed down onto the neck 3 for the knife
edge 16 to touch the surface of the sealing film 14. As the cap is
tightened, the detachment knife 15 will be elastically displaced in
an upward direction, as shown in FIG. 3, in which the detachment
knife 15 is shown as being in a substantially horizontal position.
Further tightening of the screw cap causes the detachment knife 15,
as in FIG. 4, to bend upwardly, and in the final, fully tightened
position of the screw cap 7, the detachment knife 15 with its knife
edge 16 will have moved resiliently to an oblique erect position as
a consequence of the pressure exerted by the rim 11 of the neck 3
via the circumferential zone 13 of the sealing film 14. The
detachment knife 15, resiliently deformed and under spring tension,
comes into position on the outer periphery 17 of the bottleneck 3
above the male thread 4 and below the radially overlapping
circumferential zone 13 of the sealing film 14. Its final position
is also discernible in FIG. 5.
[0058] This final position shown in FIG. 5 is such that, as the
screw cap 7 is unscrewed, the sealing film 14 will be progressively
detached and stored in the screw cap 7 between the detachment knife
15 and the top section 8 due to the action of the knife edge 16 of
the detachment knife 15, which circumferentially penetrates between
the overlapping circumference 13 of the sealing film 14 and the rim
11 of the neck 3 of the bottle 1, and initially extends obliquely
toward the sealing film 14 and toward the center axis 5, and then,
due to its continual springback action, penetrates more and more
radially inwardly toward the center axis 5. The commencement of the
action of the knife edges 16 on the sealing surface between the rim
11 or its sealing surface 12 and the sealing film 14 is shown in
FIG. 7.
[0059] In the preferred embodiment, as shown, there is, as
illustrated in the bottom view shown in FIG. 11, a plurality of
individual, single knives 15 distributed along the inside periphery
9' of the sleeve section 9 in the circumferential or screwing
direction (double arrow A) and firmly attached to the sleeve
section 9, which knives leave a clearance W in a two-dimensional
radial position in a common plane in the zone of the center axis 5,
as shown in FIG. 3, which clearance has the same diameter as, or a
diameter smaller than that of, the circular sealing surface 12 of
the rim 11 of the neck 3 of the bottle 1 or the like. In the
exemplary embodiment shown, the clearance W of the single knives 15
is equal to the inside diameter of the rim 11 of the neck 3.
Furthermore, three detachment knives are provided in this case.
[0060] It is unnecessary to emphasize that the invention is not
limited to the three detachment knives 15 shown in FIG. 11, and
that, in fact, the number of detachment knives 15 can be varied
depending on the materials used for the sealing film 14 and its
mode of attachment to the sealing surface 12 of the neck 3.
[0061] When there is only one detachment knife 15, it can be
circumferentially configured around the inside periphery 9' of the
sleeve section 9, ie, as an annular knife (not shown), in which
case the elasticity of the material of the screw cap 7 and that of
the annular knife will provide the necessary deflectability of the
latter toward the center axis 5.
[0062] Finally, concavely curved knife edges 19 have been employed
in the embodiment shown in FIG. 11, which knife edges have a
radially projecting, pointed cutting projection 20 that is trailed
in the unscrewing, rotational direction B so that the knife edges
19 extend partially in the unscrewing direction A or have a
component that points in the unscrewing direction A. This design
would appear to be suitable for facilitating the transaction of the
sealing surface. There are other conceivable geometries of the
detachment knives 15 that are suitable for achieving the object of
the invention.
[0063] A pressure lip 23, circumferentially disposed about the
center axis 5 and the sealing surface 12 and thus also disposed
opposite to the sealing film 14, for which a reinforcement disk 22
is employed in this embodiment, is formed on the inside surface 21
of the top section 8 of the screw cap 7, which lip presses the
circumferential zone 13 of the sealing film 14 and said
reinforcement disk 22 against the rim 11 of the neck 3 such that it
nestles against the rim.
[0064] Due to its length and its tendency to spring back to
substantially its initial position as the screw cap 7 is unscrewed,
the pressure lip 23 initially remains in partial contact with the
upper surface of the sealing film 14 or the reinforcement disk 22
before it detaches itself completely from the sealing film 14 or
the reinforcement disk 22 as the screw cap 7 is progressively
unscrewed.
[0065] If it proves to be necessary from the start to reinforce the
sealing film 14, due to the fact that the circumferential zone 13
is too flexible, in order to ensure optimal sliding of the
individual knives 18 beneath the sealing film 14, a reinforcement
disk 22 can also be attached flush with the upper surface of the
sealing film 14 prior to sealing, for example, by welding with a
thermoplastic compound or by gluing, in other words before the
sealing film 14 is sealingly attached to the sealing surface 12 of
the rim 11 of the neck 3 of the bottle 1.
[0066] In the present preferred embodiment shown in the figures,
however, a reinforcement disk 22 is advantageously inserted in a
screw cap according to FIG. 12 and pressed in place with a plunger
24 past the detachment knives 15 toward the top section 8. The
screw cap 7, with the stiffening or reinforcing disk 22 held in
place by the detachment knives 15, ultimately assumes the position
shown in FIGS. 1 and 2.
[0067] Unscrewing of the screw cap 7 of the present embodiment from
the position shown in FIG. 5 or FIG. 6 to the position shown in
FIG. 10 proceeds as follows:
[0068] Due to the action of the restoring forces of the three
detachment knives 15, the knife edges 16 initially nudge into the
region below the circumferential zone 13 of the sealing film 14 and
thus raise the latter together with the edge of the superimposed
reinforcement disk 22, as illustrated in FIG. 7.
[0069] On the one hand, this process is facilitated in the
preferred embodiment shown in that a concave fillet 25 designed to
fit around the rounded edge of the rim 11 of the neck 3 is provided
on that side of the erect detachment knives 15 which face the neck
3, while on the other hand those regions of the detachment knives
15 near to the knife edges 16 are rounded on the side remote from
the neck 3. In other words, the zones of the detachment knives
adjacent to the knife edges 16 are always curved, thus favoring the
penetration of the knife edges 16.
[0070] During this process, the pressure lip 23, which initially
exerted pressure against the entire zone 26 indicated by dots (FIG.
6), partially lifts from the surface of the edge of the sealing
film 14, ie, in the case illustrated here, outwardly from the edge
of the reinforcement disk 22.
[0071] As the cap is unscrewed further, the knife edges 16, due to
the elastic bending of the knife edges 16, penetrate into the
region of the sealing surface 12 which is also indicated by dots in
FIG. 6, cf FIG. 8.
[0072] In the illustrated embodiment, the detachment knives 15,
when the position shown in FIG. 9 has been attained, have pushed
their way along the entire sealing surface 12 and have completely
detached the sealing film 14 with the reinforcement disk 22.
Because the detachment knives 15 have a tendency to spring back to
their initial positions occupied on the neck 3 prior to screwing
down the screw cap 7, the situation illustrated in FIG. 10 with the
detached sealing film 14 plus the reinforcement disk 22 within the
removed screw cap 7 is achieved.
[0073] A second embodiment of the invention is illustrated in FIGS.
13 to 15. The parts corresponding to those of the first embodiment
are designated by the same reference numerals.
[0074] This embodiment also relates to a method for the at least
partial removal or detachment of a sealing film or foil 14', in
particular a film or foil composed of aluminum and/or plastics
material, sealingly attached to a rim 11 of a neck 3 of a
container, especially a bottle 1 or similar container made of
plastics material, glass, or the like, wherein the rim 11 has a
circular sealing surface 12, the neck 3 has a male thread 4 and a
center axis 5, and wherein a screw cap (7') having a female thread
(6) complementary to the male thread (4) is screwed down onto the
male thread (4) on the neck (3) sealed in the aforementioned
manner, the cap being unscrewed at a later date as required.
[0075] According to the invention, an intermediate layer 33
consisting of a thermoplastic compound, a glue, and/or a sealing
wax is introduced between the top section 8' or the inner surface
21 thereof and the sealing film 14' prior to screwing down the
screw cap 7' onto the neck 3 of the container or the bottle 1. As
the screw cap 7' is screwed down onto the neck 3 of the container
1, the intermediate layer 25 is pressed onto the sealing film 14'
by the inner surface 21 of the top section 8' and the inner surface
21 is then welded or glued to the surface of the sealing film 14'
in such a way that the sealing film 14' adheres tightly to the
inner surface 21 and, as a consequence of such adhesion, the
sealing film 14' is at least partially entrained by the screw cap
7' when the screw cap 7' is unscrewed from the neck 3 of the
container or bottle 1.
[0076] A sealing film 14' having embossments or perforations
configured as breaking points disposed at least at certain points
in a circumferential direction within the clearance W of the neck 3
is advantageously used, the inner surface 21 of the top section 8'
only being glued or welded to the surface of the sealing film 14'
in the region of the surface 32 surrounded by the embossments or
perforations 28.
[0077] The embossments or perforations considerably reduce the
effort needed to tear the sealing film 14' when unscrewing the
screw cap 7'.
[0078] A disk 31 (FIG. 15) is used as a sealing film 14' in this
exemplary embodiment, the disk being constructed of two layers 26
and 27. The layer 26 facing the inner surface 21 of the top section
8' can be composed of PE, PET, or aluminum and the layer 27 facing
the neck 3 can be composed of PE, PET, or sealing wax.
[0079] Preferably, the layer 26 of the sealing film 14' that faces
the top section 8' is embossed or perforated at its circumference
(double arrow Z, FIG. 14), at least at certain points, within the
clearance W of the neck 3.
[0080] Furthermore, the perforation (28) in the preferred exemplary
embodiment illustrated follows a circular line around the
circumference.
[0081] In a screw cap 7' for the implementation of the method
described according to this second embodiment, which is also
especially one composed of plastics material, there is a top
section 8' and a sleeve section 9', the sleeve section having a
female thread 6 and an open end 10 for screwing onto, and
unscrewing from, a male thread 4 of a neck 3 of a bottle 1 or
similar container composed of plastics material, glass or the like,
the neck 3 having a rim 11, which is hermetically sealed with a
sealing film 14' sealingly attached to a circular sealing surface
12 of the rim 11 of the neck 3 of the container 1, which sealing
film is capable of being detached or destroyed to allow access to
the contents of the bottle, and the top section 8' of the invention
has an inverted, anvil-like, inner, plate-like projection 32 that
extends toward the inner surface 21 and is configured in such a way
that the intermediate layer 33 can be pressed into position on the
surface of the sealing film 14' when the screw cap 7' is screwed
down onto the neck 3 of the container 1 or similar vessel.
[0082] In this manner, optimal gluing or welding and thus a
corresponding optimal adhesion of the top section 8' to the sealing
film 14' and reliable entrainment of the latter is achieved when
the screw cap 7' is unscrewed.
[0083] In general it has been shown to be advantageous to dimension
the thread pitch and the thread mating 4, 6 in such a way that each
3600 turn of the screw cap 7, 70 raises the screw cap 7, 70
approximately 9 mm from the neck 3.
[0084] In order to achieve this, the female thread 6 can be
configured as a triple thread.
[0085] FIG. 16 shows another embodiment of the invention involving
a screw cap 70.
[0086] In principle, it is advantageous if the degree of lift
between the screw cap 7, 70 and the neck 3 given by the thread
pitch and the mating of a male thread 4 with a female thread 6 used
is, in the fully screwed position of the screw cap 7, 70 on the
container 1, at least equal to the length of the detachment knife
or knives 15, this length in turn being at least equal to the
radial distance between the inside periphery 9' of the sleeve
section 9, from which the detachment knife 15 projects outwardly,
and an imaginary circle on the sealing surface 12 between the
sealing film 14 and the rim 11.
[0087] Preferably, the circumference of the imaginary circle is
formed by the inside periphery of the rim 11 of the neck 3 in such
a way that the at least one detachment knife 15 always completely
detaches the sealing surface 12. However, this is in no way
obligatory. In fact, it may also be sufficient not to detach the
sealing surface 12 completely, ie, not to let the knife edge(s) 19
penetrate so far, but only as far as the imaginary circle in the
zone of the sealing surface 12 on the rim 11 of the neck 3, and
complete detachment of the sealing film 14, 14' occurs as a result
of the latter being peeled off by the action of unscrewing the
screw cap 7 with the at least one detachment knife 15 then lying
under the edge of the sealing film 14'.
[0088] According to a preferred embodiment of the screw cap 70, the
at least one detachment knife 15 is disposed on the inside
periphery 9' of the sleeve section 9 above the female thread 6 and
remote from the top section 8, and the thread path of the female
thread 6 has gaps 71, the width u of which is substantially equal
to, or slightly greater than, the width of the detachment knife 15
or detachment knives in the circumferential direction of the inside
periphery 9', so that when the screw cap 70 is removed from the
mold (not shown), the at least one detachment knife 15 can be
pressed downwardly into the gaps 71 and remain briefly therein
until they emerge from the mold and are exposed.
[0089] This design involving the gaps 71 permits considerable
shortening of the height of the screw cap 70 and consequently a
saving of plastics construction material, because the detachment
knives 15 can be disposed in greater proximity to the female thread
6, which simultaneously avoids problems concerning the removal of
the screw cap 70 from the mold in which it was injection-molded,
especially in the case of the preferred use of plastics materials.
Without the gaps 71, the height of a screw cap would inevitably
have to be greater, because the detachment knives 15 inevitably
bend downwardly when the cap is removed from the mold, and without
the gaps the only place where the detachment knives could be
accommodated would be in the space above the threads.
[0090] Furthermore, it is preferable that the detachment knife 15
or each of the detachment knives used always has a free end
provided with a knife edge, which end is curved or bent toward the
rim 11 when the sealing surface 12 is penetrated between the
sealing film 14 and the rim 11 (this can be discerned particularly
clearly from FIGS. 3 and 6). This favors the penetration of the
knife edge(s) 19 between the sealing film 14 and the rim 11, not
only when the sealing film 14, which in particular is
advantageously composed of aluminum and/or plastics material, has a
circumferential zone 13 radially overlapping the rim 11 of the neck
3.
[0091] Preference is given to an embodiment in which the free end
of the at least one detachment knife 15 is also curved on both
sides in such a way that it has a spoon-like, concave curvature
(not shown) facing the rim 11.
[0092] It has been shown that such a shape makes the detachment
knife ends particularly effective in detaching the sealing film 14,
because the ends are resiliently flattened as they penetrate the
sealing surface 12 and, due to their inherent restoring forces,
they exert, in addition to the existing wedge effect, an upward and
downward separating force normal to their surface, which force
acts, on the one hand, on the sealing film 14 and, on the other
hand, on the rim 11.
[0093] Finally, the screw cap 70 can also have a counter-pressure
lip 72 (FIG. 16) in the form of an annulus disposed on the inside
of the top section 8 between at least one concentrically disposed,
in this case relatively short, ie, low-height, pressure lip 23 and
the inside surface 9' of the sleeve section 9, which
counter-pressure lip presses against the sealing film 14 when the
screw cap is screwed down onto the neck 3, and which, when the
screw cap is unscrewed, is designed to support the edge of the
sealing film 14 against the pressure of the ends of the detachment
knife or knives 15 with its restoring force in such a way that said
ends are more able to slide under the circumferential zone 13 of
the sealing film 14 and penetrate the sealing surface 12.
[0094] It must be emphasized that the circumferential zone 13 does
not necessarily have to overlap the rim 11 of the neck 3. It also
does not necessarily have to have an unglued or unsealed
circumferential edge in order to ensure optimal penetration by the
knife edge(s) 19 of the detachment knife/knives 15.
[0095] The respective design of the embodiment of the invention is
in this regard dependent on the parameters specified in each case,
of which mention may be made of the material of the screw cap
itself, the material of the sealing film 14, the material of the
adhesive used, and the elasticity of the detachment knife/knives by
way of example only. In the case of the screw cap 70, for example,
no reinforcement disk 22 is used for a sealing film 14, although
the film may require such reinforcement, as described in previous
embodiments, which is why the counter-pressure lip 72 is
advantageous in this embodiment.
[0096] In conclusion, it should be mentioned that the pressure lip
23, whether in the embodiments according to FIGS. 1 to 10 or in the
embodiment according to FIG. 16, serves not only to exert pressure
on a circumferential zone 13 of the sealing film 14, should such a
circumferential zone be present, but also to reseal the neck 3 of,
say, a bottle 1 after the sealing film 14 has been removed and when
the bottle is reclosed each time the screw cap 7, 7', or 70 is
unscrewed for the removal of part of the contents, by which means
the bottle is resealed.
* * * * *