Liquid Dispensing Tap And Liquid Container Provided With Said Tap

Abstract

Liquid dispensing tap 1 connectable to a liquid container 70, e.g. a bag in box, for controlled dispensing of a liquid therefrom. The tap includes a housing 10 forming an inlet of the tap and including a dispensing chamber wall portion 13 delimiting a dispensing chamber 14 with a valve seat 15 at an axial end and forming a dispensing outlet 17 in communication with the dispensing chamber 14. The tap 1 includes a plunger 30 with a stem 31 and a valve portion 32. The stem having an actuator engagement portion 33 outside the dispensing chamber and extending along an axis 15 through a bore 18 in the dispensing chamber wall portion and throughout the dispensing chamber. The plunger moves axially between a closed and an open position. A manually operable plunger actuator 50 engages the engagement portion of the stem to open the tap.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation in part of PCT International Application Serial No. PCT/2015/142164, entitled “Liquid Dispensing Tap And Liquid Container Provided Therewith,” filed Feb. 19, 2015, the entire specification of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE DISCLOSURE

The present invention relates to a liquid dispensing tap adapted to be connected to a liquid container, e.g. to a pouch, e.g. a pouch of a bag in box container, for controlled dispensing of a liquid from said container.

Bag in box containers are commonly used to package beverages, like wine, fruit juice, milk, and other liquids, e.g. detergents, motor oils, etc. In order to allow a user to controllable dispense the liquid from the container, e.g. to fill a glass of wine, it is known to provide the packaging with a manually operable tap. The tap can be prefitted on the pouch of the bag in box packaging or supplied along with the packaging so that the user can fit the tap.

Examples of a liquid dispensing tap are shown in GB 2 138 544 and GB 2 169 061. These known taps comprise a housing with a connector portion that is adapted to connect the tap to a liquid container and that forms an inlet of the liquid from the container into the tap. The housing further comprises a dispensing chamber wall portion which delimits a dispensing chamber. This wall portion comprises a valve seat at an axial end thereof and also forms a dispensing outlet of the tap in open communication with the dispensing chamber. The outlet is commonly downwardly directed in use, so that one can pour the liquid directly into a glass or other receptacle.

The known taps also comprises a one piece molded plastic plunger with a valve portion that is integrally molded with a stem of the plunger. The stem has an actuator engagement portion outside the dispensing chamber. The stem extends along an axis, through a bore in the dispensing chamber wall portion and through the dispensing chamber. The valve portion is embodied to cooperate with the valve seat and the plunger is movable along the axis between a closed position, wherein the tap is closed, and an open position.

The known taps comprise a push-button that serves as a manually operable plunger actuator. The push-button is connected to the engagement portion of the stem of the plunger and by depressing the push-button the user opens the tap to dispense the liquid.

Such liquid dispensing taps are mass produced, low cost products as they are commonly disposed when the container has been emptied. Cost price is therefore one issue associated with such taps. However other issues, such as the closing effect of the tap in order to guarantee the quality of the liquid in the container or the behaviour of the tap as it is operated by the user also play a role.

The present invention aims to propose measures that provide improvements over the known taps and liquid containers provided with such taps.

SUMMARY OF THE DISCLOSURE

According to a first aspect thereof the present invention provides a liquid dispensing tap adapted to be connected to a liquid container according to claim 1, wherein the axis along which the stem extends is a vertical axis and the plunger has an integrally molded annular flexible sealing lip that extends around the stem, and wherein the bore, here the first bore, forms a first cylinder along said axis, and wherein the sealing lip slides within and sealingly engages the first cylinder in any position of the plunger.

The above inventive measure provides a reliable seal between the dispensing chamber through which the liquid flows towards the outlet on the one hand and the location of the plunger actuator on the other. Furthermore the sealing structure provides an enhanced guidance of the stem relative to the housing with frictional forces being governed by the sealing lip. This e.g. allows for enhanced control by the user when opening the tap and/or for enhanced retraction of the plunger to its closed position, e.g. retraction by means of a resilient material push button acting as actuator of the tap.

In an embodiment the stem has a small diameter section connected to the actuator engagement portion and large diameter section within the dispensing chamber. The stem has a shoulder between these small and large diameter sections.

In an embodiment the annular flexible sealing lip extends from the shoulder of the stem of the plunger concentrically about the small diameter section of the stem. This design provides in an efficient manner a stable base for the flexible sealing lip and allows for efficient injection molding of the plunger.

In a preferred embodiment the valve seat has a substantially cylindrical valve seat surface, wherein the valve portion is embodied as a dish with a flexible peripheral rim that is primarily compressed in radial direction when contacting the valve seat surface. In contrast to valves with a conical valve seat, this valve design does not require an exact axial position of the plunger in order for the tap to be reliably closed, nor does the design require the valve portion mating with the valve seat to be very flexible in order to absorb any tolerances in the parts of the tap or any axial misalignment of the plunger. Therefore this tap design allows the designer, when desired, to embody the valve portion semi-rigid or at least with a relative rigidity that enhances the closing effect of the tap compared to a very flexible conical valve.

In a preferred embodiment the axial movement of the plunger between the closed position and the open position is a vertical movement. In this embodiment the valve portion of the plunger in the closed position sealingly engages with the valve seat, while in the open position one or more openings are formed between the valve portion and the dispending chamber. These openings may for instance be formed between the valve portion and the dispensing outlet thereof. The openings allow the fluid to be dispensing from said tap.

In a preferred embodiment the dispensing chamber comprises a second bore forming a second cylinder. Said second bore and second cylinder are preferably coaxially with and offset axially with respect to said first bore and first cylinder. The stem and the valve portion of the plunger extend through said second bore, and the valve seat and dispensing outlet are formed at the axial end of said second cylinder.

In this embodiment the dispensing outlet is thus downwardly directed in use.

In this embodiment the valve seat is provided adjacent the dispensing outlet.

The provision of the first and second cylinder, wherein said second cylinder comprises said valve seat and wherein the dispensing outlet is formed at the axial end of said second cylinder, allow for efficient injection moulding of the dispensing chamber.

The provision of the valve seat in the second cylinder is advantageously combined with the the valve seat having a substantially cylindrical valve seat surface, wherein the valve portion is embodied as a dish with a flexible peripheral rim that is primarily compressed in radial direction when contacting the valve seat surface. In an embodiment comprising a valve seat within the second cylinder and a valve portion embodied as a dish as described above, the substantially cylindrical valve seat surface is a portion of the inner surface of the second cylinder. Preferably the inner surface of the second cylinder is at the site of the valve seat embodied as a smooth cylindrical surface without any indentations or protrusions. Such an embodiment of the valve seat provides further ease of manufacturing.

In an embodiment comprising the second cylinder as described above the internal cross-sectional area of the second cylinder is enlarged at the dispensing outlet, so as to provide the abovementioned one or more openings between the valve portion and the dispensing outlet. The enlargement of the internal cross-sectional area may be effected in various ways, such as to provision of a conical inner surface at the end of the second cylinder, the provision of indentations in the inner surface of the second cylinder or the provision of a non-linear, e.g. curved or stepwise, increase of the internal cross-section.

In an embodiment comprising the second cylinder as described above the housing has an outer wall portion forming an exterior of the tap. Said outer wall portion comprises a portion of the second cylinder, for instance the dispensing outlet thereof, for instance the dispensing outlet and the valve seat thereof. The first cylinder on the other hand is provided within and radially spaced from said outer wall portion. The first cylinder is preferably connected to the outer wall portion by cylinder connecting portions that substantially extends radially outwards with respect to the first cylinder.

In a preferred embodiment, liquid can enter from the connector portion into the dispensing chamber unobstructed. In other words, no stops, e.g. valves, are provided at said interface between the connector portion and the dispensing chamber.

In a further development hereof the stem has a hollow cavity that extends from an open end at the side of the valve portion through the large and small diameter sections to a blind end at the side of the engagement portion. This is advantageous in view of rigidity of the valve stem and in view of injection molding the plunger. In an embodiment the greater diameter section of the stem has a diameter that is at least 35% of the diameter of the valve portion, e.g. between 35% and 75%, thus providing a stable base for the valve portion. In an embodiment the stem has one or more axial reinforcement ribs within the hollow cavity, e.g. only in a larger inner diameter section of the hollow cavity corresponding to the larger diameter section of the stem.

In an embodiment the valve seat has a substantially cylindrical valve seat surface and the valve portion is embodied as a dish with a flexible peripheral rim that is primarily compressed in radial direction when contacting the valve seat surface. Preferably the rim extends away from the dish in the direction of opening the tap. For example the dish is conical, arranged at an angle in the opening direction relative to the stem, and the rim is substantially cylindrical, e.g. with a spherical ring sector contour.

In an embodiment the stem is hollow with an open end at the valve portion and a blind end at the side of the engagement portion. This enhances the manufacture of the plunger by means of injection moulding and allows to obtain increased rigidity whilst efficient use is made of plastic material. In an embodiment the stem has one or more axial reinforcement ribs within the hollow cavity.

In an embodiment, as known from the mentioned prior art and common in the field, the actuator is a manually depressable push button, that is exposed to allow operation by a user's finger, e.g. a thumb. Preferably the exterior of the housing has one or more finger grip members allowing a user to grip the housing with one or more fingers and depress the push button using the thumb.

Other embodiments of the actuator are also possible, e.g. a depressable lever, a rotary knob, etc.

In an embodiment, as known from the mentioned prior art and common in the field, the actuator comprises a resilient biasing member providing a biasing force on the plunger urging the plunger to the closed position thereof. Preferably the push button is embodied as a one piece resilient material push button providing said biasing force. For example the push button is made of polypropylene (PP) or Polyoxymethylene (POM).

In an embodiment the actuator comprises a one piece resilient polypropylene material push button providing said biasing force. It has been found that polypropylene as material for the push button offers the desired resiliency and form restoring properties to obtain the biasing of the plunger to the closed position. Also polypropylene offers desired durability for use in the tap. In an alternative the push button is made of an elastomer, e.g. a thermoplastic elastomer (TPE).

In an embodiment the one piece resilient material push button has a collar portion that is secured to the housing of the tap and a depressable wall bridging the collar portion. In an embodiment the collar portion is held on a tubular retention wall portion of the housing, e.g. the collar portion clamping elastically on said inner retention wall portion, e.g. the collar portion having circular ridges on the inner face thereof that enhance the retention of the tubular retention wall portion, e.g. said wall portion having mating circular grooves.

In an embodiment a depressable wall portion of the one piece molded resilient plastic material push button has a user engagement face with a central area and has a stem connector portion at the opposite face. In non-mounted condition of the push button the central area is axially raised relative to the outer perimeter of the wall portion. Between the central area and the outer perimeter the depressable wall portion has multiple concentric undulations that enhance the resiliency and form restoring effect of the wall portion. As is preferred the outer perimeter is integral with a collar portion described above.

In an embodiment an undulation is formed by three concentric and integral regions:

• • a first conical annular region, widening towards the outer perimeter of the wall portion,
  • an intermediate radial annular region, adjoining the first conical annular region and extending substantially in a radial plane of the push button,
  • a second conical annular region, adjoining the intermediate radial annular region and widening towards the outer perimeter of the wall portion.

For example, the push button has two undulations between the central area and the outer perimeter.

In an embodiment, as known from the mentioned prior art, the push button comprises a snap fit collar serving as stem connector. The snap fit collar having an outer diameter, which snap fit collar is snap fitted over a snap fit head forming an engagement portion of the stem of the plunger.

In an embodiment, the snap fit collar has an outer diameter that is smaller than the inner diameter of the first cylinder of the dispensing chamber wall portion, so as to allow to be partially inserted into said first cylinder when the plunger actuator, e.g. manually depressable push button, has been actuated and in response thereto the plunger is displaced in downward direction along the vertical axis.

In an alternative embodiment, the snap fit collar has an outer diameter that is larger, e.g. slightly larger, than the inner diameter of the first cylinder of the dispensing wall portion, so that the top end of the first cylinder is a cylinder stop end face and the end of the snap fit collar is a snap fit collar stop end face.

According to a second aspect thereof the present invention relates to a liquid dispensing tap according to claim 13, wherein the stem has a small diameter section connected to the actuator engagement portion and large diameter section within the dispensing chamber, wherein the stem has a shoulder between said small and large diameter sections, and wherein the stem is hollow cavity that extends from an open end at the valve portion through the large and small diameter section to a blind end at the side of the engagement portion.

As the stem is the structural backbone of the plunger, this design allows to create a robust stem even if relatively resilient, e.g. semi rigid plastic material is used to manufacture the stem, or, as is preferred, a one piece plunger having the stem, the valve portion and, if desired, the flexible sealing lip according to the first aspect of the invention.

In an embodiment the greater diameter section of the stem has a diameter that is at least 35% of the diameter of the valve portion, so that the stem provides a stable base for the valve portion. For example the stem has a diameter about 50% of the valve portion diameter.

It will be appreciated that the tap of the second aspect of the invention may include any of the details, including optional details, discussed herein with reference to the tap according to the first aspect of the invention.

According to a third aspect thereof the present invention relates to a liquid dispensing tap according to claim 15, wherein a manually operable push button is connected to the engagement portion of the stem of the plunger allowing a user to open the tap for dispensing of liquid, which push button is embodied as a one piece resilient material push button providing a biasing force on the plunger urging the plunger to the closed position thereof, and wherein the push button is made of polypropylene (PP) or a thermoplastic elastomer (TPE).

It has been found that polypropylene as material for the push button offers the desired resiliency and form restoring properties to obtain the biasing of the plunger to the closed position. Also polypropylene offers desired durability for use in the tap. A thermoplastic elastomer (TPE) can be used also as material for the push button.

It will be appreciated that the tap of the third aspect of the invention may include any of the details, including optional details, discussed herein with reference to the tap according to the first aspect of the invention.

According to a fourth aspect thereof the present invention relates to liquid dispensing tap according to claim 16, wherein the push button is embodied as a one piece resilient material push button providing a biasing force on the plunger urging the plunger to the closed position thereof, wherein the push button has a depressable wall portion with a user engagement face having a central area and with a stem connector portion at an opposite face of said central area, wherein the push button has an outer perimeter secured to the housing of the tap,

and wherein the push button has multiple concentric undulations between the central area and the outer perimeter of the depressable wall portion, preferably the central area being axially raised relative to the outer perimeter of the depressable wall portion.

The provision of undulations enhances the resiliency and form restoring effect of the wall portion, e.g. allowing for the advantageous use of polypropylene (PP), or a thermoplastic elastomer (TPE), to manufacture the push button.

It will be appreciated that the tap of the fourth aspect of the invention may include any of the details, including optional details, discussed herein with reference to the tap according to the first aspect of the invention.

The present invention also relates to a container, e.g. a pouch, e.g. a pouch of a bag in box container, provided with a liquid dispensing tap according to one or more of the aspects of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be discussed with reference to the drawings. In the drawings:

FIG. 1 shows a perspective view of an example of a liquid dispensing tap according to the invention,

FIG. 2 shows the tap of FIG. 1 from below in perspective view,

FIG. 3 shows the tap of FIG. 1 in cross-section, with the tap being closed,

FIG. 4 shows a detail of FIG. 3 on a larger scale, and

FIG. 5 shows in perspective view the housing of the tap of FIG. 1.

DETAIL DESCRIPTION OF THE DRAWINGS

In the drawings a liquid dispensing tap 1 is shown that is adapted to be connected to a liquid container, e.g. to a pouch of a bag in box container, for controlled dispensing of a liquid from the container. For example the pouch of the bag in box container is filled with a beverage, e.g. wine. The pouch may be provided with a fitment to which the tap 1 is connected or the tap 1 can be directly connected to the pouch. Instead of a pouch the container may also have another design, e.g. as a bottle, canister, etc.

The tap 1 is, as is preferred, assembled from just three one piece plastic components:

• • a housing 10,
  • a plunger 30,
  • a push button 50.

As is known in the art the tap 1 can be provided with a removable covering seal that extends over the outlet in order to an opening any ingress of foreign matter.

The housing 10 is preferably a rigid and one piece injection molded plastic part.

The housing 10 comprises a connector portion 11 that is adapted to connect the tap to a liquid container and forms an inlet 12 of the tap via which liquid from the container enters the tap 1.

The housing 10 further comprises, as integral part thereof as is preferred, a dispensing chamber wall portion 13 delimiting a dispensing chamber 14 having a vertical axis 15. This dispensing chamber wall portion 13 comprises a valve seat 16 at an axial end thereof and forms a dispensing outlet 17 of the tap 1 that is in open communication with the dispensing chamber 14.

The plunger 30 is, as is preferred, a one piece molded plastic plunger. Preferably the plunger is made of a plastic material that is less rigid than the plastic material of the housing 10, e.g. of a semi rigid plastic material.

The plunger 30 has a stem 31 and a valve portion 32 that is integrally molded with the stem 31. The stem 31 has an actuator engagement portion 33 outside the dispensing chamber, generally at the front side of the tap 1 in practical use. The stem 31 extends along the vertical axis 15 through a first bore 18 in the dispensing chamber wall portion 13 and through the dispensing chamber 14.

The valve portion 32 is embodied to cooperate with the valve seat 16. The plunger 30 is axially movable or reciprocable along the axis 15 between a closed position, wherein the tap 1 is closed, and an open position, wherein the tap is open.

As a third and here final component the tap 1 comprises the push button 50 that acts as manually operable plunger actuator of the tap 1. The button 50 is coupled to the engagement portion 33 of the stem 31 of the plunger 30 and allows a user to open the tap 1 for dispensing of liquid from the container.

The first bore 18 forms a first cylinder 19 along the axis 15. The plunger 30 has an integrally molded annular flexible sealing lip 34 that extends around the stem 31. This lip 34 slides within and sealing engages the first cylinder 19 in any position of the plunger 30.

The stem has a small diameter section 31a connected to the actuator engagement portion 33 and large diameter section 31b within the dispensing chamber 14. The stem 31 has a shoulder 35 between the small and large diameter sections 31a, 31b.

The annular flexible sealing lip 34, that provides a seal and support where the plunger 30 extends through the wall portion 13, extends from the shoulder 35 and is concentric about the small diameter section 31a of the stem 31.

The valve seat 16 has a substantially cylindrical valve seat surface, e.g. with none or a minimal tapering, e.g. less than 6 degrees taper.

The valve portion 32 is embodied as a dish 36 with a flexible peripheral rim 37 that is primarily compressed in radial direction when contacting this cylindrical valve seat surface of the valve seat 16.

The axial movement of the plunger 30 between the closed position and the open position is a vertical movement, wherein the valve portion 32 of the plunger in the closed position sealingly engages with said valve seat 16. In the open position a opening, here an annular opening, is formed between the valve portion 32 and the dispensing outlet 17 of the dispensing chamber.

The dispensing chamber 14 comprises a second bore 21 forming a second cylinder 20, wherein said second bore 21 and second cylinder 20 are coaxial with and offset axially with respect to said first bore 18 and first cylinder 19. This is most apparent in FIGS. 3-5. The stem 31 and the valve portion 32 of the plunger extend through said second bore, and the valve seat 16 and dispensing outlet 17 are formed at the axial end of said second cylinder.

In the embodiment of FIGS. 1-5 the dispensing chamber further comprises a conduit chamber 22 in between the connector portion 11 of the housing and the second bore 21. An aperture in the surface of the second cylinder provides fluid communication between the second bore and the conduit chamber 22. Thus, in order to be dispensed the fluid flows through the connector portion 11, the conduit chamber 22, the second bore 21 and through the dispensing outlet 17 of the dispensing chamber 14.

The internal cross-sectional are of the second cylinder 20 is enlarged at the dispensing outlet 17 through the provision of a conical inner surface to the second cylinder at the end thereof, so as to provide the annular opening between the valve portion and the dispensing outlet when the plunger is in the open position.

The housing 10 has an outer wall portion forming an exterior of the tap 1. Said outer wall portion comprises a portion of the second cylinder 20, here the dispensing outlet 17 and a portion of the valve seat 16 thereof. The first cylinder 19 is provided within and radially spaced from said outer wall portion of the housing 10.

The stem 31 is a hollow cavity stem, or a tubular stem, with a hollow cavity 38 that extends from an open end at the valve portion 32 through the large and small diameter sections 31a,b to a blind end at the side of the engagement portion 33.

The manually depressable push button 50 is exposed to allow operation by a user's finger, e.g. a thumb. In the shown embodiment the push button 50 is embodied as a one piece resilient material push button, as is preferred of polypropylene (PP) material, providing a biasing force on the plunger 30 urging the plunger to the closed position thereof. In an alternative the push button is made of an elastomer, e.g. a thermoplastic elastomer (TPE).

The push button 50 comprises a snap fit collar 51 having an outer diameter. This snap fit collar 51 is snap fitted over a snap fit head 33 forming the engagement portion of the stem 31.

The snap fit collar 51 has an outer diameter that is smaller than the inner diameter of the first cylinder 19 of the dispensing chamber wall portion 13, so as to allow said snap fit collar 51 to be partially inserted into said first cylinder when the plunger actuator 50, e.g. manually depressable push button, has been actuated and in response thereto the plunger 30 is in the open position.

The push button 50, embodied as a one piece resilient material push button, provides the biasing force that urges the plunger 30 to the closed position. So when the user release the button 50, the button 50 exerts said biasing force, e.g. the button being made of polypropylene (PP).

The push button 50 has a collar portion 53, here circular as is preferred, that is secured to the housing of the tap 1 and a depressable wall 54 bridging the collar portion 53.

The collar portion 53 is held on a tubular retention wall portion 29 of the housing, here a cylindrical wall portion 29 protruding axially from the chamber wall portion 13, opposite the chamber 14.

The collar portion 53 here clamps elastically on the inner retention wall portion 29. To enhance the retention the collar portion has circular ridges 53a on the inner face thereof and the wall portion has mating circular grooves. In another embodiment the collar portion 53 is fitted within a tubular retention wall, e.g. with mating formations on the outside of the collar portion and the inside of the retention wall.

The depressable wall portion 54 has a user engagement face, or front face, with a central area 56. The collar 51 is integral with said area at the opposite or rear side of the button 50. As shown in FIGS. 7 and 8, in the non-mounted condition of the push button, the central area 56 is axially raised relative to the outer perimeter 57 of the wall portion, which perimeter 57 adjoins the collar 53.

Between the central area 56 and the outer perimeter 57 the depressable wall portion 54 has multiple concentric undulations 58, 59 that enhance the resiliency and form restoring effect of the wall portion 54.

As shown here each undulation 58, 59 is formed by three concentric and integral regions:

• • a first conical annular region 58a, widening towards the outer perimeter of the wall portion,
  • an intermediate radial annular region 58b, adjoining the first conical annular region and extending substantially in a radial plane of the push button,
  • a second conical annular region 58c, adjoining the intermediate radial annular region and widening towards the outer perimeter of the wall portion.

In the embodiment shown here the push button 50 has two undulations 58, 59, whereas in another embodiment the button may have a single undulation.

Claims

1. A liquid dispensing tap (1) adapted to be connected to a liquid container, e.g. a pouch (70), e.g. a pouch of a bag in box container (75), for controlled dispensing of a liquid from said container, the tap comprising:

a housing (10) comprising: a connector portion (11) adapted to connect the tap to a liquid container and forming an inlet of the tap, a dispensing chamber wall portion (13) delimiting a dispensing chamber (14) having a vertical axis (15), which dispensing chamber wall portion comprises a valve seat (16) at an axial end thereof and forms a dispensing outlet (17) of the tap in open communication with said dispensing chamber,

a one piece molded plastic plunger (30) having a valve portion (32) that is integrally molded with a stem (31) of the plunger, wherein the stem has an actuator engagement portion (33) outside said dispensing chamber (14) and wherein the stem extends along said axis (15) through a first bore (18) in said dispensing chamber wall portion (13) and through the dispensing chamber, wherein the valve portion (32) is embodied to cooperate with the valve seat (16), and wherein the plunger is axially movable between a closed position, wherein the tap is closed, and an open position, wherein the tap is open,

a manually operable plunger actuator (50) which engages said engagement portion of the stem of the plunger allowing a user to open the tap for dispensing of liquid,

characterized in that the plunger (30) has an integrally molded annular flexible sealing lip (34) that extends around the stem (31),

and in that the first bore (18) forms a first cylinder (19) along said axis (15), and wherein the sealing lip (34) slides within and sealing engages the first cylinder (19) in any position of the plunger (30).

2. A tap according to claim 1, wherein the stem (31) has a small diameter section (31a) connected to the actuator engagement portion (33) and large diameter section (31b) within the dispensing chamber (14) and wherein the stem (31) has a shoulder (35) between said small and large diameter section.

3. A tap according to claim 2, wherein the annular flexible sealing lip (34) extends from said shoulder (35), concentrically about the small diameter section (31a) of the stem.

4. A tap according to claim 1, wherein the valve seat (16) has a substantially cylindrical valve seat surface, and wherein the valve portion is embodied as a dish (36) with a flexible peripheral rim (37) that is primarily compressed in radial direction when contacting said valve seat surface.

5. A tap according to claim 1, wherein the axial movement of the plunger between the closed position and the open position is a vertical movement, wherein the valve portion of the plunger in the closed position sealingly engages with said valve seat and wherein in the open position one or more openings are formed between the valve portion and the dispensing chamber, e.g. the dispensing outlet of the dispensing chamber, which openings allow fluid to be dispensed.

6. A tap according to claim 1, wherein the dispensing chamber comprises a second bore forming a second cylinder, said second bore and second cylinder coaxial with and offset axially with respect to said first bore and first cylinder, wherein the stem and the valve portion of the plunger extend through said second bore, and wherein the valve seat and dispensing outlet are formed at the axial end of said second cylinder.

7. A tap according to claim 6, wherein the internal cross-sectional area of the second cylinder is enlarged at the dispensing outlet, e.g. through the provision of a conical inner surface or indentations to the second cylinder at the end thereof, so as to provide one or more openings between the valve portion and the dispensing outlet.

8. A tap according to claim 6, wherein the housing has an outer wall portion forming an exterior of the tap, wherein said outer wall portion comprises a portion of the second cylinder, e.g. the dispensing outlet thereof, e.g. the dispensing outlet and the valve seat thereof, and wherein the first cylinder is provided within and radially spaced from said outer wall portion.

9. A tap according to claim 1, wherein the stem (31) is hollow with an open end at the side of the valve portion (32) and a blind end at the side of the engagement portion (33).

10. A tap according to claim 1, wherein the actuator is a manually depressable push button (50), that is exposed to allow operation by a user's finger, e.g. a thumb.

11. A tap according to claim 1, wherein the actuator comprises a resilient biasing member providing a biasing force on the plunger urging the plunger to the closed position thereof, preferably in an embodiment of claim 11 the push button (50) being embodied as a one piece resilient material push button providing said biasing force.

12. A tap according to claim 10, wherein the push button (50) comprises a snap fit collar (51) having an outer diameter, which snap fit collar is snap fitted over a snap fit head (33) forming the engagement portion of the stem of the plunger.

13. A liquid dispensing tap (1) adapted to be connected to a liquid container, e.g. a pouch (70), e.g. a pouch of a bag in box container (75), for controlled dispensing of a liquid from said container, the tap comprising:

a housing (10) comprising: a connector portion (11) adapted to connect the tap to a liquid container and forming an inlet of the tap, a dispensing chamber wall portion (13) delimiting a dispensing chamber (14) having a vertical axis (15), which dispensing chamber wall portion comprises a valve seat at an axial end thereof and forms a dispensing outlet (17) of the tap in open communication with said dispensing chamber,

a plunger (30) comprising a stem (31) and a valve portion (32), wherein the stem has an actuator engagement portion (33) outside said dispensing chamber and wherein the stem extends along said axis through a first bore in said dispensing chamber wall portion and through the dispensing chamber (14), wherein the valve portion (32) is embodied to cooperate with the valve seat, and wherein the plunger (30) is axially movable between a closed position wherein the tap is closed and an open position wherein the tap is open,

a manually operable plunger actuator (50) which engages said engagement portion of the stem of the plunger allowing a user to open the tap for dispensing of liquid,

characterized in that the stem (31) has small diameter section (31a) connected to the actuator engagement portion (33) and a large diameter section (31b) within the dispensing chamber (14), wherein the stem has a shoulder (35) between said small and large diameter sections, and wherein the stem has a hollow cavity (38) that extends from an open end at the valve portion (32) through the large and small diameter sections (31a,b) to a blind end at the side of the engagement portion (33).

14. A tap according to claim 13, wherein the greater diameter section (31b) of the stem has a diameter that is at least 35% of the diameter of the valve portion (32).

15. A liquid dispensing tap (1) adapted to be connected to a liquid container, e.g. a pouch (70), e.g. a pouch of a bag in box container (75), for controlled dispensing of a liquid from said container, the tap comprising:

a housing (10) comprising: a connector portion (11) adapted to connect the tap to a liquid container and forming an inlet of the tap, a dispensing chamber wall portion (13) delimiting a dispensing chamber (14) having a vertical axis (15), which dispensing chamber wall portion comprises a valve seat (16) at an axial end thereof and forms a dispensing outlet of the tap in open communication with said dispensing chamber,

a plunger (30) comprising a stem (31) and a valve portion (32), wherein the stem has an actuator engagement portion (33) outside said dispensing chamber and wherein the stem extends along said axis through a first bore (18) in said dispensing chamber wall portion and through the dispensing chamber, wherein the valve portion (32) is embodied to cooperate with the valve seat (16), and wherein the plunger is axially movable between a closed position wherein the tap is closed and an open position wherein the tap is open,

a manually operable push button (50) which is connected to said engagement portion of the stem of the plunger allowing a user to open the tap for dispensing of liquid, which push button is embodied as a one piece resilient material push button providing a biasing force on the plunger urging the plunger to the closed position thereof,

characterized in that the push button (50) is made of polypropylene (PP) or a thermoplastic elastomer (TPE).

16. A liquid dispensing tap (1) adapted to be connected to a liquid container, e.g. a pouch (70), e.g. a pouch of a bag in box container (75), for controlled dispensing of a liquid from said container, the tap comprising:

a housing (10) comprising: a connector portion (11) adapted to connect the tap to a liquid container and forming an inlet of the tap, a dispensing chamber wall portion (13) delimiting a dispensing chamber (14) having a vertical axis (15), which dispensing chamber wall portion comprises a valve seat (16) at an axial end thereof and forms a dispensing outlet (17) of the tap in open communication with said dispensing chamber,

a plunger (30) comprising a stem (31) and a valve portion (32), wherein the stem has an actuator engagement portion (33) outside said dispensing chamber and wherein the stem extends along said axis through a first bore (18) in said dispensing chamber wall portion and through the dispensing chamber, wherein the valve portion (32) is embodied to cooperate with the valve seat, and wherein the plunger (30) is axially movable between a closed position wherein the tap is closed and an open position wherein the tap is open,

a manually operable push button (50) which is connected to said engagement portion of the stem of the plunger allowing a user to open the tap for dispensing of liquid, which push button is embodied as a one piece resilient material push button providing a biasing force on the plunger urging the plunger to the closed position thereof,

wherein the push button has a depressable wall portion (54) with a user engagement face having a central area (56) and with a stem connector portion (51) at an opposite face of said central area, wherein the push button has an outer collar portion (53) secured to the housing of the tap,

characterized in that

the push button (50) has multiple concentric undulations (58,59) between the central area (56) and the outer perimeter (57) of the depressable wall portion (54), preferably the central area being axially raised relative to the outer perimeter (57) of the depressable wall portion (54).

17. A container, e.g. a pouch (70), e.g. a pouch of a bag in box container (75), provided with a liquid dispensing tap (1) of claim 1.