[0001] The present invention relates to a closure for mounting on a liquid container and
comprising a tap valve and air reflux means to allow vent air to enter the container
as the liquid exits so as to avoid low pressure to build up within the container,
resulting in an air lock and a possible collapse of the container.
BACKGROUND OF THE INVENTION
[0002] Dispenser tabs for liquid containers are advantageously combined with a vent opening
for allowing reflux air to enter the container so as to avoid low pressure to build
up within the container, resulting in an air lock and a possible collapse of the container.
A vent opening may be provided as a second opening arranged at the opposite end of
the container as the tap opening. Such a vent opening may however have the drawback
that the plug for sealing the opening during transportation of the container is removed
when the container is prepared for dispensing and there is a risk that the plug is
lost when the container has been emptied and is to be sealed off and returned for
refilling or destruction, which results in spillage of remaining liquid and possible
contamination of the interior of the container with external contaminants entering
through the non-sealed vent opening.
[0003] Closures integrating a dispenser tap and an opening for letting vent air into a container
as liquid is drained from it are well known in the prior art. These tabs are primarily
intended for use with single-opening containers that are not vented by a second opening
arranged at the opposite end of the container as the tap opening.
[0004] A spigot tap is known from US 3,378,035, comprising a spigot with two openings, one
for pouring out liquid and one for taking in reflux air, wherein the tap is opened
by aligning both with the respective openings to the interior of the liquid container
and open concurrently, so that reflux air is let into the container only while liquid
is poured out. A rigid air tube extends into the container and upwards from the opening
for reflux air, so as to provide an air exit above the level of the tap at running
conditions.
[0005] A tap with a similar rigid air tube is disclosed in FR 2608722.
[0006] A beverage dispenser is disclosed in US 4,664,297, in which a dispensing valve can
be coupled with the threaded necks of bottles. A rigid vent tube connected with the
dispensing valve extends deeply into the beverage bottle to avoid an air lock impeding
flow through the valve. The bottle is when the dispensing valve is in use, arranged
in an upside-down inclined position, so that the vent tube extends upwards and into
the air filled space at the bottom of the bottle opposite the neck portion of the
bottle.
[0007] An improved venting of the liquid container, resulting in an increased dispensing
rate, is advantageous to obtain and it is an object of the present invention to provide
such improved venting.
[0008] The closure according to the present invention integrates a dispenser tap and an
opening for letting vent air into a container as liquid is drained from it, and provides
an improved venting, as at least a part of the vent air conduct is made from a flexible
tube and buoyancy means are provided near the distal, open end of the conduct extending
in the interior of the container from the vent opening in the closure, so that the
open end will be near below, at or above the free surface of the liquid inside the
container. Hereby, the pressure of the vertical liquid column between the opening
of the conduct and the free surface is reduced or eliminated and the reflux air may
flow more freely and an improved venting is provided.
[0009] The known integrated closures comprises rigid vent air conducts that are shaped and
positioned so as to ensure that the opening at the distal end is situated within the
liquid container at a position that is higher than the position of the liquid outlet.
Thereby, it is made certain that a difference in pressure between the opening of the
vent air conduct and the liquid outlet exists which counteracts an outflow through
the vent air conduct. The length of the vent air conduct has to be limited for the
integrated closure to be applicable to containers of various sizes and shapes.
[0010] By providing a flexible vent air conduct combined with buoyancy means near the distal,
open end of the conduct according to the invention, an integrated closure is obtained
that provides improved venting of the container while being flexible with respect
to size and shape of the container to which it may be applied. In fact, the venting
may be improved to such a degree that the integrated closure according to the present
invention may render the use of a second vent opening in the container redundant.
The closure according to the invention may also be used in combination with such second
vent opening to improve the venting rate of the container.
DESCRIPTION OF THE INVENTION
[0011] Thus, the present invention relates to a closure suitable for mounting on a mouth
situated on the lower part of a liquid container, the closure comprising
tap valve means for controlling the flow of liquid out of the liquid container,
and
air reflux means for admitting vent air into the liquid container, the air reflux
means comprising a vent air conduct for extending into the liquid container from a
vent opening in the closure connecting to the exterior,
wherein
the vent air conduct comprises an elongated, flexible tube and is at a distal, open
end provided with buoyancy means so as to bias the open end towards the free surface
of the liquid in the container.
[0012] The tap valve means may be a spigot tap, e.g. as the one disclosed in US 3,378,035,
a ball valve, a globe valve or any other type of valve that is suitable for the intended
use, e.g. with respect to flow rate, requested adjustment features, durability and
price.
[0013] The air reflux means comprises one or more vent openings in the closure, either in
the mounting cap part of the closure, through the tap valve or both. Each vent opening
is connected to the vent air conduct that may comprise one or more elongated, flexible
tubes as described, each provided with buoyancy means. In a preferred embodiment,
each vent opening is connected to a separate flexible tube.
[0014] The buoyancy means is means that in the relevant liquid will create sufficient buoyancy
to lift the flexible tube or tubes upwards towards the free surface. The open end
may not actually reach the free surface if the distance between the mouth of the liquid
container and the free surface of the liquid exceeds the length of the tube; the venting
of the liquid container is still improved substantially. However, it is preferred
that the open end reaches the free surface. It is also preferred that the buoyancy
means is arranged such that the open end of the vent air conduct extends from and
opens above said free surface, so that the liquid will not enter the tube opening.
It is under most conditions sufficient that the tube end extends 5 to 10 millimetres
upwards from the free surface of the liquid, but under operational conditions where
the container moves, e.g. on board a ship, it is preferred that the tube extends up
to 25 to 30 millimetres from the free surface.
[0015] The buoyancy means may be made from natural materials, such as cork, wood or sponge,
or from man made materials, such as foam made from polyurethane, polyethylene, polypropylene,
etc. In embodiments of the present invention employing more than one flexible tube,
a common buoyancy means is preferably used for all tubes.
[0016] The free surface of the liquid is defined as the upper, horizontal surface between
the liquid and the air, as opposed to the surfaces bonded by container walls.
[0017] The tubes connected with the vent openings are flexible as opposed to the rigid tubes
used in the prior art to ensure that the tube opening was above the level of the liquid
discharge opening in the tap. The flexibility of the present tubes together with the
buoyancy created by the buoyancy means has the effect that the open, distal end of
the vent air conduct is biased towards the free surface of the liquid, i.e. that the
open end is actually moved towards the free surface when the closure is mounted onto
the liquid container. The required degree of flexibility is thus determined by the
effect of the buoyancy means, so that the desired outcome is achieved. The flexible
tube constitutes in preferred embodiments only a part of the vent air conduct, as
the conduct leading from the vent opening and inside the container is constituted
by a rigid tube, and the tubing through the buoyancy means is also preferably constituted
by a rigid tube. The flexible tube may be made from any suitable material, such as
natural or synthetic rubber, and the inner diameter of the tube is preferably in the
range of 2-10 mm for most application, more preferred within the range of 4-6 mm,
but inner diameters deviating from these ranges may also be applied in accordance
with the invention.
[0018] The buoyancy effect of the buoyancy means it influenced by the density of the liquid
within the container, i.e. whether it is a light liquid containing e.g. alcohol, oil
or gasoline, a medium density liquid with a density around that of water, or whether
it is a heavy liquid containing high density components, e.g. as suspended particles
in a liquid. However, the buoyancy means may be selected for a specific liquid, or
the closure may be formed with all-round buoyancy means suitable for a wide range
of liquid densities.
[0019] It has proven to be an advantage that the buoyancy means is formed with a distance
between its centre of gravity and its centre of buoyancy, so as to ensure a given
spatial orientation of the open end of the vent air conduct relative to the buoyancy
means. The spatial orientation may be that the opening is at the uppermost possible
position, which may be advantageous when the opening is below the free surface as
well as when the opening is at or above the free surface, or another specific orientation
for openings above the free surface may be preferred in order to prevent liquid from
entering the openings.
[0020] The distance between the centre of gravity and the centre of buoyancy may be obtained
by having a non-uniform density distribution of the buoyancy means. This may e.g.
be of the form of a gradually changing density of the material the buoyancy means
is formed from, or it may be obtained by including a member of a deviant density,
preferably a high-density member such as a lump of metal, e.g. lead, in the buoyancy
means displaced from the buoyancy centre thereof. The deviant density member may alternatively
be a section of a lower-density material, e.g. an air-filled cavity, or the buoyancy
means may comprise a plurality of high-density and/or lower-density members, the terms
high-density and lower-density refer to the density relative to the average density
of the material of the buoyancy means.
[0021] The risk of spillage of liquid through the vent opening or openings is highest during
the operation of mounting the closure on the container and during transportation of
the container with the closure mounted thereon. As one solution to this problem, the
vent opening or openings may be provided with a plug or plugs that may be inserted
when there is a risk of spillage through the vent opening or openings. The air reflux
means may comprise one or more non-return valves arranged in some of or all of the
tubes constituting the vent air conduct for preventing liquid from flowing out of
the one or more vent openings.
[0022] As another alternative that may be used alone or in a combination with the non-return
valve or valves and/or the plug or plugs, a vent valve means may be operational connected
to the tap valve means to control the passage between at least one vent opening and
the open end of the corresponding vent air conduct concurrently with the control of
the flow of liquid out of the liquid container. An examples hereof is given below
and may also be found in the prior art, e.g. in US 3,378,035.
[0023] The closure comprises preferably connecting means for providing a releasable, sealed
connection between the closure and a liquid container, such as a releasable snap-in
socket. However, it is preferred the connecting means comprises an externally or internally
threaded part on the closure means for engaging with a corresponding threaded part
on the liquid container. The connecting means may comprise a mounting cap as discussed
in the examples below.
[0024] The present invention further relates to a liquid container having a closure according
to the above described mounted on a mouth at a lower part thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0025] The present invention is further explained by means of the examples of embodiments
shown in the enclosed drawing, of which Figs. 1-4 show a prior art tap known from
US 3,378,035,
Fig. 1 is an exploded elevation of a spigot tap, part being shown in cross-section,
Fig. 2 is a section taken along II-II of Fig. 1,
Fig. 3 is a cross-section taken along III-III of Fig. 1,
Fig. 4 is a cross-section taken along IV-IV of Fig. 1,
Fig. 5 is a cross-section of a first embodiment of the closure of the present invention
mounted on a liquid container,
Fig. 6 is a cross-section of a second embodiment of the closure of the present invention
mounted on a liquid container, and
Fig. 7 is a mounting cap for the closure according to the second embodiment of the
present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0026] The tap shown in Figs. 1-4 is a prior art tap that may be employed in a closure according
to the present invention. However, other types of taps may as discussed previously
be employed as well.
[0027] The tap shown in the drawing consists of a spigot part 1 rotatable in fluid-tight
engagement within a sleeve part 2. The sleeve part 2 has integral therewith a tubular
gland 3, whose axis is perpendicular to the rotational axis of the spigot part and
which is formed to engage within the mouth or other delivery opening of the liquid
container. Obviously the form of the gland 3 depends upon the kind of opening with
which it is to be engaged and the form shown in the drawing is shown by way of example
only. A mounting cap may be provided to mount the tap on a specific kind of container
opening.
[0028] Communication between the gland 3 and the sleeve part 2 is provided by a large liquid
part 4. An integral tubular projection 6 within the gland communicates with the sleeve
part by an air port 5 and has secured thereto a separately formed air tube 7 shaped
to enter the container and provide an air exit at 8 above the level of the tap under
running conditions.
[0029] The spigot part consists of a tubular moulding open at its lower end 9 and having
a handle 10 at its closed upper end. Adjacent to the upper end the spigot part is
formed externally with circumferential ridge of enlarged diameter between a pair of
grooves, which ridge and grooves co-operate with complementary formations 12 within
the liner to locate the spigot part axially.
[0030] Formed in the wall of the spigot are a liquid entrance port 13 shaped and positioned
to correspond with the port 4 and an air exit port 14 positioned to correspond with
the small air port 5.
[0031] Internally the spigot part is divided by a septum 15 having a tight sliding fit within
a pair of longitudinal grooves 16 and 17. The lower end of the spigot part is cut
through at the bases of the grooves to provide short slots for the reception of transversely
projecting lugs 18 and 19 provided at the lower en of the septum 15. The slot for
the reception of lug 19 is shown at 20 in Fig. 3.
[0032] At its upper end the septum 15 has a segmental part 21, the curved edge of which
is a close mating fit at 21' with the inner surface of the spigot between the ports
13 and 14.
[0033] By the septum 15, the spigot part is divided to provide a liquid delivery passageway
leading from the entrance port 13 to a liquid exit at the open end of the spigot part
and an air reflux passageway, of smaller cross-sectional area than the liquid delivery
passageway, leading from the open end of the spigot part to the exit port 14. The
open end of the spigot part is of course divided to form the liquid exit and air entrance
by the lower edge of the septum.
[0034] With the spigot 1 rotated to position the ports 13 and 14 out of communication with
the ports 4 and 5, the tap provides a satisfactory seal for the container. On turning
the spigot within the sleeve part, the exit port 14 is placed in communication with
air port 5 and entrance port 13 with the liquid port 4. The circumferential displacement
of the edge 21A of the exit port 14 beyond the edge 22 of the entrance port 13, by
an amount equal to the circumferential displacement between the corresponding edges
of the port 4 and 5, ensures that the air and liquid passageways begin to communicate
with the container at the same moment. When the liquid is being delivered, air passes
into the container via end 8 of the tube, or from the end of tubular projection 6
if tube 7 is omitted.
[0035] In Fig. 5, a first embodiment of the present invention is disclosed, in which the
tap 23 as discussed above and shown in Figs. 1-4 is mounted by means of a mounting
cap 24 (only indicated) on the mouth of a container 25 containing a liquid 26. The
use of the known tap 23 is made for illustrative purposes and other kinds and types
of taps could be employed, either integrating or not integrating a vent opening 5
that is closed by a valve 1.
[0036] A flexible tube 27 is at one end connected to the air tube 7 of the tap 23 and at
the other end connected to a rigid tube 28 passing through a float 29 made from polyurethane
foam. The float 29 has outer dimensions that allow it to pass the standard openings
of containers 25. The length of the flexible tube 27 and dimensions of the container
25 allow the float 29 to reach the free surface 30 of the liquid 26. However, it is
also within the scope of the present invention to provide embodiments in which the
float does not reach the surface 30 but only bias the outlet of the open end 31 of
the vent air conduct 14, 5, 7, 8, 27, 28 towards the free surface 30 of the liquid
26.
[0037] A second embodiment of the present invention is shown in Fig. 6, in which a further
vent opening 32 is provided in the mounting cap 24 and a further rigid air tube 33
extends from the vent opening 32 and into the container 25. A second flexible tube
34 is at one end connected to the air tube 33 and at the other end to a rigid tube
35 passing through the float 29 that also provides buoyancy for the first flexible
tube 27, and the rigid tube 35 is open 36 towards the air filled space 37 at the top
of the container 25. The parts referred to as 32, 33, 34, 35 and 36 thereby establish
a second path of the vent air conduct.
[0038] Two separate floats could has been provided as well, and the use of rigid tubes 7,
28, 33, 35 at the two ends of the flexible tubes 27, 34 may be omitted and the flexible
tubes 27, 34 may extend all the way from the vent openings 5, 32 to the open ends
31, 36 of the vent air conduct. More corresponding vent openings and thereto communicating
open ends may also be added if further venting of the container is required.
[0039] Fig. 7 shows a mounting cap 24 for use with the second embodiment shown in Fig. 6.
The mounting cap 24 is above seen from the outside of the container 25 and below seen
in a cross-section. The cap 24 has a central opening 38 for receiving the gland 3
of the tap and holding the gland 3 in a tight and sealing connection. The mounting
cap 24 is at the outer periphery 39 provided with indentations 40 to enhance the user's
grip of the mounting cap during the mounting and dismounting operation. One vent opening
32 is provided in the middle section 41 of the cap 24 between the central opening
38 and the periphery 39, but more similar vent openings may be provided.
[0040] The mounting cap 24 is provided with an internal thread 42 for cooperating with a
corresponding external thread of the mouth of the container 25, but other means of
releasable, sealed connections between the cap 24 and the container 25 may be provided.
[0041] The mounting cap 24 may be provided with various types of connection means and diameters
to mount the tap on various types of container mouths. However, the mounting cap is
not a required or essential part of the present invention, and the closure may be
integrated in the tap valve or the tap valve a shown in the first example may be mounted
directly to a container having a suitable mouth.
1. A closure suitable for mounting on a mouth situated on the lower part of a liquid
container (25), the closure comprising
tap valve means (23) for controlling the flow of liquid (26) out of the liquid
container (25), and
air reflux means (5, 14, 7, 27, 28, 31, 32, 33, 34, 35, 36) for admitting vent
air into the liquid container (25), the air reflux means comprising a vent air conduct
(7, 27, 28, 33, 34, 35) for extending into the liquid container (25) from a vent opening
(5, 32) in the closure connecting to the exterior,
characterised in that
the vent air conduct comprises an elongated, flexible tube (27, 34) and is at a distal,
open end (31, 36) provided with buoyancy means (29) so as to bias the open end (31,
36) towards the free surface (30) of the liquid (26) in the container (25).
2. A closure according to claim 1, wherein the buoyancy means (29) is arranged such that
the open end (31, 36) of the vent air conduct opens above said free surface (30).
3. A closure according to claim 1 or 2, wherein the buoyancy means (29) is formed with
a distance between its centre of gravity and its centre of buoyancy, so as to ensure
a given spatial orientation of the open end (31, 36) of the vent air conduct relative
to the buoyancy means (29).
4. A closure according to claim 3, wherein said distance is obtained by including a member
of deviant density in the buoyancy means (29), displaced from the buoyancy centre
thereof.
5. A closure according to any of claims 1 to 4, wherein the air reflux means comprises
a non-return valve for preventing liquid from flowing out of the vent opening (5,
32).
6. A closure according to any of claims 1 to 5, wherein the air reflux means comprises
a plurality of vent openings (5, 32) in the closure and the vent air conduct comprises
a corresponding number of elongated, flexible tubes (27, 34) provided with buoyancy
means (29).
7. A closure according to any of claims 1 to 6, wherein a vent valve means operational
connected to the tap valve means (23) controls the passage between at least one vent
opening (5) and the open end (31) of the corresponding vent air conduct concurrently
with the control of the flow of liquid out of the liquid container (25).
8. A closure according to any of the preceding claims, further comprising connecting
means for providing a releasable, sealed connection between the closure and a liquid
container.
9. A closure according to claim 8, wherein the connecting means comprises a threaded
part (42) on the closure means for engaging with a corresponding threaded part on
the liquid container (25).
10. A liquid container (25) having a closure according to any of claims 1-9 mounted on
a mouth at a lower part thereof.