GB2537471A

GB2537471A - A fluid coupling

Info

Publication number: GB2537471A
Application number: GB1603258.3A
Authority: GB
Inventors: Gerard O'brien Michael
Original assignee: Packaging Innovation Ltd
Current assignee: Packaging Innovation Ltd
Priority date: 2016-02-25
Filing date: 2016-02-25
Publication date: 2016-10-19
Anticipated expiration: 2036-02-25
Also published as: GB2537471B; GB201603258D0

Abstract

A fluid coupling 10 comprises a first portion 9 and a second portion 11. The first portion 9 comprises neck 15 which sealingly engages with the second portion 11, and a bung 18 which seals the neck 15 when the first portion 9 is not connected to the second portion 11. The second portion 11 comprises an inlet and an engagement mechanism 22, 27, 28 which is located in or extending through the inlet. The engagement mechanism 22, 27, 28 displaces bung 18 relative to the neck 15 allowing fluid to flow through the neck 15 when the two portions are engaged, and it replaces bung 18 to reseal the neck 15 when the two portions are disengaged. The neck 15 can seal with the inlet prior to the engagement mechanism 22, 27, 28 displacing the bung 18, in a dry break type arrangement. The engagement mechanism 22, 27, 28 can comprise arms extending towards the first portion which can be forced radially outwards to engage with the surface of the bung 18 by a locking element when the two portions 9, 11 are brought together, the engagement mechanism 22, 27, 28 thereby gripping the bung 18.

Description

A fluid coupling A first aspect of the present invention relates to a fluid coupling and particularly, but not exclusively, to a fluid coupling suitable for use with a disposable fluid container. A second aspect of the invention relates to a dispenser comprising such a coupling.

Quick connect fluid couplings are known and examples are disclosed in US Patent Application Publication Number U52016/0003394 Al and UK Patent Application Publication Number GB2528013A1. These are commonly used to connect hoses together or to connect a hose to an outlet for a fluid and typical applications include garden, pneumatic or hydraulic hoses and fittings.

With quick connectors of the above type, it is often desirable that these be what is termed "make before break" or "dry break couplings", where each part of the coupling, normally male and female, comprises a mechanism for sealing that part of the coupling before a seal between the two parts is broken.

In applications where the coupling is arranged to be separated with pressurised fluid in the line, it is normally necessary to seal both parts of the coupling, for the upstream part of the coupling may still be receiving pressurised fluid and both the upstream and downstream parts of the coupling are still likely to contain pressurised fluid, even when the supply has been terminated.

Another common type of fluid coupling is that used for connecting containers, (possibly intended to be disposable) to a dispenser. The container may be rigid or in the form of a collapsible bag and the dispenser will often be arranged such that a liquid drains from the container under gravity. Couplings for such containers typically employ a first part of the coupling mounted to the dispenser and a second part of the coupling forming part of the container. Often, placing the container in the dispenser, or on the dispenser, causes the first and second parts of the coupling to seal prior to the part of the coupling on the dispenser rupturing, or otherwise breaking, the seal of that part of the coupling attached to the container.

With the type of couplings described immediately above, it is not normally possible to subsequently close the container, but this is not problematic for it is not normally desirable to remove the container until it is empty. Even if the container should not be empty, then it is normally acceptable to drain the container through the dispenser, as the requirement to change the container will normally be necessitated by the fluid in the container, having passed its serviceable life, as for example in the case of a reservoir on a drinking water dispenser.

An advantage of the above type of coupling is that the portion of the coupling in the container, which may be disposable, can be relatively cheap to produce having no moving parts, other than some type of membrane which may be ruptured, or a similar "one shot" arrangement.

With a dispenser arranged to dispense chemicals, there may be a requirement for the chemicals be delivered in a non-returnable container to be mounted in a dispenser, which when empty is then disposed of. For many applications a coupling as described above, where a membrane is broken, is desirable due to the low cost. However in some applications, it would be desirable to be able to reseal the container to prevent smells emanating from the container and also to prevent any residual liquid seeping out of the container, while the container is awaiting disposal. This can be done by having an auxiliary cap, which can be manually replaced, but this requires the cap to be retained and a person to ensure this task is performed.

It is an object of the present invention to provide an improved fluid coupling.

According to a first aspect of the present invention there is provided a fluid coupling comprising a first portion and a second portion arranged to releasably couple together to establish a fluid path through the two portions, the first portion comprising: a neck arranged to sealingly engage with a second portion of the coupling; and a bung arranged to seal the neck when the first portion is not connected to the second portion, the second portion comprising an inlet for sealing with and receiving fluid from the neck of the first portion, the second portion further comprising an engagement mechanism in or extending through the inlet, the engagement mechanism being arranged to engage with the bung to displace the bung relative to the neck to allow fluid to flow through the neck and to subsequently replace the bung in the neck to reseal the neck.

An advantage of the invention described above is that the first portion of the coupling only requires an appropriately shaped neck and a bung to seal the neck and no other components. This may be particularly advantageous if the first portion of the coupling is intended to be disposable, where for example it forms the outlet of a disposable container, with the second portion of the coupling intended to be reusable, for example it may form part of a dispenser for receiving successive disposable containers. The advantage of the invention is that the mechanical components for opening and closing the neck of the disposable first portion of the coupling are retained in the second portion of the coupling which may be intended to be reusable.

Advantageously the engagement mechanism is arranged such that the action of moving the first and second portions of the coupling together causes the neck to seal with the inlet, prior to the engagement mechanism displacing the bung from the neck, with a subsequent action of moving the first and second portions of the coupling apart, causing the engagement mechanism to replace the bung in the neck and reseal the neck prior to the seal between the neck and the inlet being broken. This is advantageous, for the action of moving the first and second portions of the coupling together may be arranged to displace the bung and open the neck of the container, with the action of subsequently pulling the first and second portions of the coupling apart causing the engagement mechanism to first replace the bung prior to the seal between the first and second couplings being broken, providing a substantially dry lock mechanism, although there may be some liquid retained in the second portion of the coupling. This may all be achieved without any action being taken, other than pushing the two portions of the coupling together and subsequently pulling them apart Advantageously the engagement mechanism displaces the bung relative to the neck in a direction away from the second portion of the coupling and replaces the bung by drawing the bung relative to the neck in a direction towards the second portion. This permits the direct action of moving the two portions of coupling together to displace the bung and the direct action of moving the two portions of the coupling apart to replace the bung.

Preferably the bung has an outer face, facing towards an open mouth of the neck, the outer face of the bung being shaped to permit the engagement mechanism to engage with the outer face and hold the bung. This permits the engagement mechanism in the second part of the coupling to directly engage with the bung.

Advantageously the coupling has a longitudinal axis and the engagement mechanism comprises a plurality of arms extending generally in the direction of the longitudinal axis towards the first portion of the coupling, the second portion of the coupling further comprising a locking member arranged such that it adopts a first position relative to the arms as the two portions of the coupling are brought together, the locking member in the first position permitting: the two portions of the coupling to be brought together; a seal to be made between the neck of the first portion of the coupling and the inlet of the second portion of the coupling; and the arms to contact, or almost contact the bung, wherein continuing to move the first and second portions of the coupling closer together, causes the locking member to move to a second position relative to the arms, where the locking member extends the arms in a substantially radial direction so that they engage and hold the bung, wherein continuing to move the first and second portions of the coupling together causes the bung to be displaced in the neck away from the second portion of the coupling. This permits a single movement drawing two portions of the coupling together axially, to first make the seal between two portions of the coupling and then subsequently release the bung.

It is particularly advantageous if subsequently moving the first and second portions of the coupling apart, causes the bung to be moved by the engagement mechanism to reseal the neck, with subsequent continued movement causing the locking member to release the arms from engagement with the bung and then causing the neck to move in an axial direction away from the inlet, breaking the seal between the neck of the first portion of the coupling and the inlet of the second portion of the coupling.

Advantageously the second portion of the coupling comprises: a main body to which the locking member is fixed; a clip comprising the plurality of arms slideably mounted in the axial direction relative to the main body; a first biasing means biasing the clip to an extended position in the axial direction relative to the main body, in use towards the first portion of the coupling; a connector slideably mounted in the axial direction relative to the main body having the inlet on a face of the connector distal to the main body; and a second biasing means biasing the connector in the axial direction relative to the main body, in use towards the first portion of the coupling, wherein: the second biasing means is arranged to permit the inlet to receive the neck of the first portion and seal with the neck prior to the second biasing means permitting the connector to move axially with the neck until the arms come into contact with, or nearly come into contact with, the bung with the arms and clip being held in the extended position by the first biasing means, the first biasing means then permitting the arms and clip to move axially with the neck relative to the main body and the locking member, causing the locking member to force the arms into engagement with the bung and hold the bung.

The above arrangement permits the direct forces applied to bring the two portions of the coupling together, to also perform the tasks of sealing the two portions of the coupling and opening the bung, all in one linear axial motion. (Although it is to be noted that the axial movement of the clip relative to the locking member will cause displacement of the arms in a non-axial, radial direction to hold the bung).

Preferably the main body, connector and clip are generally tubular and coaxially arranged one in side of the other, with the locking member also extending coaxially within the clip.

The outer face of the bung may have a circumferential rim with a recess on a radially inward facing surface of the rim, with the arms arranged to be expanded radially by the locking member, when in the second position, to lock the arms into the recess of the bung. This permits the bung to be relatively simple in construction and avoids the bung having to have any particular alignment with the locking mechanism, thus avoiding the need for the first portion of the coupling to have any particular alignment with the second portion of the coupling, other than for the two portions to be axially aligned.

Advantageously the locking means is resilient and in the second position is arranged to resiliently engages the arms to act to retain the arms axially in position relative to the locking member, until a force is applied to the first and second portions of the coupling acting to axially separate them, which force is sufficient to overcome the resilience of the locking member to permit the locking member to move axially relative to the arms away from the second portion of the coupling, to permit the arms to release the bung. This results in the locking mechanism keeping the arms in engagement with the bung until a significant force is applied and thus ensures the bung is firmly replaced in the neck of the first portion of the coupling prior to the arms releasing the bung.

According to a second aspect of the invention there is provided a disposable container for use with the coupling in accordance with the first aspect of the invention, wherein the first portion of the coupling comprises a straw of the container and preferably the container comprises only the straw, a membrane heat welded or otherwise sealed to the straw and a fluid to be dispensed, thereby providing a particularly cost effective resealable container which may be desirable for disposable applications.

According to the third aspect of the present invention there is provided a dispenser comprising a coupling in accordance with the first aspect of the invention, the dispenser further comprising a housing having the second portion of the coupling mounted thereto and a container, the container having the first portion of the coupling in the form of a straw of the container. The dispenser has an intended upright orientation where the second portion of the coupling is located below the first portion of the coupling, with a longitudinal axis of the coupling aligned vertically and with the inlet of the second portion of the coupling facing vertically upwards. With such an arrangement, the second portion of the coupling may form part of the dispenser and be intended to be used with multiple disposable containers. Furthermore the vertical axial alignment of the coupling, with the second portion below the first portion, ensures that on separation of the first portion from the second portion of the coupling, the bung sealing the neck of the container prior to the seal between the two portions of the coupling being broken will ensure the container can be removed even if it is still partly full. It is also particularly advantageous if any residual fluid in the coupling is retained in the second portion of the coupling.

The dispenser may comprise means for engaging the first portion of the coupling, to locate it in the dispenser and to then move the first and second portions of the coupling axially together along a substantially vertical axis. In this manner the dispenser can ensure that the two portions of the couplings are correctly aligned and furthermore the dispenser can be arranged to provide a convenient and possibly mechanically advantageous mechanism, by which a user may insert a container into the dispenser and reliably make the coupling. For example, the operation of closing a front panel on the dispenser housing may be arranged to bring the two portions of the coupling into engagement with one another, with the action of subsequently opening the front panel then separating the two portions of the coupling.

One embodiment of the present will now be described by way of example only with reference to the accompanying figures of which; Figure 1 illustrates a coupling in accordance with the first aspect of the invention, where a first portion of the coupling forms part of a container in accordance with the second aspect of the invention and the container forms part of a dispenser in accordance with a third aspect of the invention; Figure 2 is a cross section through the coupling of the dispenser of Figure 1, with two portions of the coupling aligned but not connected; Figure 3 corresponds to Figure 2 but with the two portions of the coupling engaged and sealed together; Figure 4 corresponds to Figures 2 and 3 but with the second portion of the coupling engaging the bung of the first portion of the coupling; Figure 5 corresponds to Figures 2 to 4 but with the bung removed from a neck of the first coupling; Figure 6 corresponds to Figures 2 to 5 but with the bung replaced in the neck of the first coupling; Figure 7 corresponds to Figures 2 to 6 but with the second portion of the coupling released from the bung of the first portion of the coupling; and Figure 8 corresponds to Figures 2 to 7 but with the second portion of the coupling separated from the first portion of the coupling, returning to the position shown in Figure 2.

Referring now to the Figure 1, a dispenser is indicated generally as 1 which has a handle 2 on the top by which the dispenser 1 is to be held in an upright position as shown.

The handle 2 has a button 3 on the top thereof which controls a valve 4 in a main housing of the dispenser for releasing fluid through the base of the dispenser. Within the housings there is a container, indicated generally as 6, which comprises a collapsible fluid filled bag 7 having a straw 8 at the bottom thereof. The straw 8 forms a first portion 9 of a coupling, indicated generally as 10, with a second portion 11 of the coupling attached to a base 12 of the dispenser 1. The housings of the dispenser 1 has a pair of lugs 13 extending from a rear wall of the housing, which lugs 5 engage the first portion 9 of the coupling 10 and retain the first portion 9 in a fixed position relative to the housing 5.

The housings of the dispenser 1 of Figure 1 has a front panel (not shown) attached to the housing S by a hinge mechanism 14. The hinge mechanism 14 raises and lowers the base of the dispenser 12 relative to the housings and thus, when the front panel opens a disposable container 6 may be inserted being retained in place by lugs 13. Then the action of closing the front panel causes the base 12 of the dispenser to be raised bringing the first and second portions 9, 11 of the coupling 10 together, as described below with reference to Figures 2 to 5. Subsequently opening the front panel pulls the first and second portions 9, 11 of the coupling 10 apart, as described below with reference to Figure 6 to 8.

Referring to Figure 2 the coupling, indicated generally as 10, is shown in greater detail and from Figure 2 it can be seen that the first portion of the coupling, indicated generally as 9, is formed from part of the straw 8 of container 6. The first portion 9 of the coupling 10 has a neck 15 at a lower edge thereof which has an outer sealing surface 16 and an inner surface 17, the inner sealing surface 17 sealing with a bung 18 to retain fluid in the container 6. The first portion 9 of the coupling also has two circumferential ridges 19 for engaging with the lugs 13 extending from the rear wall of the housings of the dispenser 1 as described above with reference to Figure 1.

With continued reference Figure 2, the second portion of the coupling, indicated generally as 11, is fixed to the base of the dispenser 12, which base 12 may be raised in the direction of the arrows 20 by the action of closing the front panel of the dispenser once the container 6 has been inserted. The second portion 11 of the coupling 9 comprises a main body 21 which is generally in the form of a cylinder with a closed bottom end. An outlet (not shown) connects the internal space defined by the cylindrical main body 21 to the valve 4 of Figure 1, for controlling the dispensing of fluid stored in the container 6.

A cylindrical connecter 22 is coaxially slideably mounted in the cylindrical main body 21 and sealed to the main body by a seal 23. The connector 22 has, at an upper distal end thereof, a sealing surface 24 for sealing with the outer sealing surface 16 on the neck 15 of the first portion 9 of the coupling 10. The connector 22 is retained in the position shown in Figure 2, by spring 25 acting between the main body 21 and a step 26 formed on an inner surface of the connector 22.

Extending from the bottom of the main body 21 is a locking member 27. This is formed of a resilient plastic material and has an outer cylindrical surface with a profile as shown. Coaxially mounted on this is a cylindrical clip 28. This generally has the form of a cylindrical tube with a circumferential protrusion 29 on an inner surface thereof. The clip 28 is biased upwardly as shown relative to the locking member 27 by a second spring 30. The clip 28 is retained in place on the locking member 27 by the circumferential protrusion 29 on the clip 28 engaging with a circumferential protrusion 31 on the outer surface of the locking member 27.

The upper portion of the clip 28, above the circumferential protrusion 29, has a number of equally spaced vertical slits dividing the substantially cylindrical wall of the clip 28 into a plurality of arms 32. These are described in greater detail below with reference to Figure 3.

Referring now to Figure 3, this shows the coupling 10 as the front panel of the dispenser 1 starts to close, raising the base 12 of the dispenser 1 in direction of the arrows 20. This causes the neck 15 to engage and seal with the connector 22, against the force of the second spring 30. In the position shown in Figure 3 bulbous heads 33 at the distal ends of the arms 32 of the clip 28 come into contact with the bung 18. The bung 18 has a circumferential rim 34 with a recess 35 on an inward facing surface thereof. As seen from Figure 3 the bulbous heads 33 of the arms 32 extend into the circumferential rim 34 of the bung 18, being biased to this position by the action of the first spring 25, urging the clip 28 upwards as shown.

Referring now to Figure 4, further closing of the front panel causes the base of the dispenser 12 to continue moving in the direction of the arrows 20, raising the main body 21 of the second portion 11 of the coupling 10 as shown in Figure 3. This causes the neck 15, which is fixed in position relative to the housings of the dispenser 1 of Figure 1, to move the connector 22 downwards as shown, relative to the main body 21 of the coupling, against the action of the second spring 30. At the same time the bung 18, being in contact with the bulbous heads 33 of the arms 32, urges the clip 28 downwards relative to the main body 21 of the second portion 11 of the coupling 10, against the action of the first spring 25 which is relatively weak. Further travel of the clip 28 is limited, by the clip 28 coming into contact with the bottom of the main body 21, as shown in Figure 4.

From a comparison of Figures 3 and 4 it can be seen that the above described movement of the second portion 11 of the coupling 10 axially towards the first portion 9 of the coupling 10, causes the bulbous heads 33 of the arms 32 to move effectively downwards on the external surface of the locking member 27, until they engage with a recess 36 in the outer surface of the locking member 27. The locking member 27 forces the bulbous heads 33 of the arms 32 outwards, into engagement with the recess 35 on the bung 18 and these act to lock the bung 18 to the arms 32 and thus the clip 28, as shown in Figure 4.

With reference now to Figure 5, further movement of the base 12 of the dispenser, in the direction of the arrows 20, raises the second portion 11 of the coupling further, with the connector 22 sliding down the inside of the main body 21, effectively raising the bung 18 out of the neck 15 of the container 6 to permit fluid to flow from the container 6 to the internal space within the main body 21 and thus to the valve 4 of Figure 1.

Referring now to Figure 6, when the container 6 is empty, or when it is otherwise desired to replace the container, the front panel of the dispenser is opened, lowering the base of the dispenser 12 in the direction of arrows 37. This causes the bung 18 to be drawn by the clip 28 back into sealing engagement with the neck 15. During this action the bung is firmly retained in place on the bulbous heads 33 of the clip 28, by the action of the locking member 27, with the profile of the recess 36 on the locking member 27 being such that the bulbous heads 33 cannot easily be displaced from the recess 35 of the bung 18.

With reference now to Figure 7, further movement of the base 12 of the dispenser, in the direction of arrows 37, results in the bung 18 being firmly sealed within the neck 15 before the bung 18, engaged with the bulbous heads 33 of the clip 28, draws the bulbous heads 33 out of the recess 36 of the locking member 27. The protrusion 29 on the clip 28 then engage with the protrusion 31 on the locking member 27, as shown in Figure 7 whereby further displacement of the base 12 in the direction of the arrows 37 causes the first portion of coupling 9 to separate from the second portion of the coupling 11, as shown in Figure 8. Here the seal between the neck 15 and connector 22 has been broken, but only after the bung 18 is firmly in place and sealing the neck 15 of the container 6.

With reference to Figure 8, it will be noted that even if the container 6 is not empty, at the point at which the first portion 9 of the coupling separates from the second portion 11 of the coupling, due to gravity there will be no residual fluid from the container retained on the outside of the container. Furthermore, even if the valve 4 of Figure 1 is closed and there is residual fluid in the second portion 11 of the coupling 10, on breaking of the seal between the first portion 9 and the second portion 11 of the coupling 10, all residual fluid will be retained within the second portion 11 of the coupling.

If the fluid Gin the container is particularly odorous, then the coupling illustrated avoids any residual fluid being on the outside of the container 6 and ensures that the container 6 is sealed so that any residual fluid on the inside of the container is sealed within the container 6. Residual fluid in the second portion 11 of the coupling is not problematic, for this will be sealed by the next replaceable container 6 being installed in the dispenser 1, or alternatively any residual fluid can be drawn out of the second portion 11 of the coupling via the valve 4 of Figure 1.

Although one embodiment of the invention has been described above with reference to the accompanying figures, it will be appreciated that many modifications may be made which fall within the scope of the appended claims. Particularly, an embodiment has been illustrated where the coupling is employed in a dispenser, but the coupling may have many other applications. Also in the dispenser application illustrated, a first portion of the coupling is brought into engagement with the second portion of the coupling by mechanical means. However it will be appreciated that the two portions of the coupling may be brought together manually by a user.

Claims

Claims 1. A fluid coupling comprising a first portion and a second portion arranged to releasably couple together to establish a fluid path through the two portions, the first portion comprising: a neck arranged to sealingly engage with a second portion of the coupling; and a bung arranged to seal the neck when the first portion is not connected to the second portion, the second portion comprising an inlet for sealing with and receiving fluid from the neck of the first portion, the second portion further comprising an engagement mechanism in or extending through the inlet, the engagement mechanism being arranged to engage with the bung to displace the bung relative to the neck to allow fluid to flow through the neck and to subsequently replace the bung in the neck to reseal the neck.
2. A fluid coupling as claimed in claim 1 wherein the engagement mechanism is arranged such that the action of moving the first and second portions of the coupling together causes the neck to seal with the inlet prior to the engagement mechanism displacing the bung from the neck, with a subsequent action of moving the first and second portions of the coupling apart, causing the engagement mechanism to replace the bung in the neck and reseal the neck prior to the seal between the neck and the inlet being broken.
3. A fluid coupling as claimed in claims 1 or 2 wherein the engagement mechanism displaces the bung relative to the neck in a direction away from the second portion of the coupling and replaces the bung by drawing the bung relative to the neck in a direction towards the second portion.
4. A fluid coupling as claimed in any preceding claim wherein the bung has an outer face, facing towards an open mouth of the neck, the outer face of the bung being shaped to permit the engagement mechanism to engage with the outer face and hold the bung.
5. A fluid coupling as claimed in claim 4 wherein the coupling has a longitudinal axis and the engagement mechanism comprises a plurality of arms extending generally in the direction of the longitudinal axis towards the first portion of the coupling, the second portion of the coupling further comprising a locking member arranged such that it adopts a first position relative to the arms as the two portions of the coupling are brought together, the locking member in the first position permitting: the two portions of the coupling to be brought together; a seal to be made between the neck of the first portion of the coupling and the inlet of the second portion of the coupling; and the arms to contact, or almost contact the bung, wherein continuing to move the first and second portions of the coupling closer together, causes the locking member to move to a second position relative to the arms, where the locking member extends the arms in a substantially radial direction so that they engage and hold the bung, wherein continuing to move the first and second portions of the coupling further together causes the bung to be displaced in the neck away from the second portion of the coupling.
6. A fluid coupling as claimed in claim 5 wherein subsequently moving the first and second portions of the coupling apart causes the bung to be moved by the engagement mechanism to reseal the neck, with subsequent continued movement causing the locking member to release the arms from engagement with the bung and then causing the neck to move in an axial direction away from the inlet, breaking the seal between the neck of the first portion of the coupling and the inlet of the second portion of the coupling.
7. A fluid coupling as claimed in claims and 6 wherein the second portion of the coupling comprises: a main body to which the locking member is fixed; a clip comprising the plurality of arms slideably mounted in the axial direction relative to the main body; a first biasing means biasing the clip to an extended position in the axial direction relative to the main body, in use towards the first portion of the coupling; a connector slideably mounted in the axial direction relative to the main body having the inlet on a face of the connector distal to the main body; and a second biasing means biasing the connector in the axial direction relative to the main body, in use towards the first portion of the coupling, wherein: the second biasing means is arranged to permit the inlet to receive the neck of the first portion and seal with the neck prior to the second biasing means permitting the connector to move axially with the neck until the arms come into contact with, or nearly come into contact with, the bung with the arms and clip being held in the extended position by the first biasing means, the first biasing means then permitting the arms and clip to move axially with the neck relative to the main body and the locking member, causing the locking member to force the arms into engagement with the bung and hold the bung.
8. A fluid coupling as claimed in any one of claims 5 to 8 wherein the main body, connector and clip are generally tubular and coaxially arranged one in side of the other, with the locking member extending coaxially within the clip.
9. A fluid coupling as claimed in any one of claims 5 to 8 wherein: the outer face of the bung has a circumferential rim with a recess on a radially inward facing surface of the rim and the arms are arranged to be expanded radially by the locking member, when in the second position, to lock the arms into the recess of the bung.
10. A fluid coupling as claimed in any one of claims 5 to 9 wherein the locking means is resilient and in the second position resiliently engages the arms to act to retain the arms axially in position relative to the locking member until a force is applied to the first and second portions of the coupling acting to axially separate them, which force is sufficient to overcome the resilience of the locking member to permit the locking member to move axially relative to the arms away from the second portion of the coupling to permit the arms to release the bung.
11. A disposable container for use with a coupling as claimed in any preceding claim, wherein the first portion of the coupling comprises a straw of the container.
12. A disposable container as claimed in claim 11 comprising only the straw, a membrane heat welded or otherwise sealed to the straw and a fluid to be dispensed.
13. A dispenser comprising a coupling as claimed in any preceding claim, the dispenser further comprising a housing having the second portion of the coupling mounted thereto and a container, the container having the first portion of the coupling in the form of a straw of the container, wherein the dispenser has an intended upright orientation and when in the upright orientation the second portion of the coupling is located below the first portion of the coupling, with a longitudinal axis of the coupling aligned vertically and with the inlet of the second portion of the coupling facing vertically upwards.
14. A dispenser as claimed in claim 13 comprising means for engaging the first portion of the coupling to locate it and to move the first and second portions axially together along a substantially vertical axis.
15. A dispenser as claimed in claim 13 or 14 wherein the container may be removed prior to being empty without spillage, with any residual fluid in the coupling being retained in the second portion of the coupling.
16. A coupling substantially as hereinbefore described with the reference to, or as illustrated in, one or more of the accompanying figures.
17. A dispenser substantially as hereinbefore described with reference to, or as illustrated in, one or more of the accompanying figures.Amendments to the claims have been made as follows: Claims 1. A fluid coupling comprising a first portion and a second portion arranged to releasably couple together to establish a fluid path through the two portions, the first portion comprising: a neck arranged to sealingly engage with a second portion of the coupling; and a bung arranged to seal the neck when the first portion is not connected to the second portion, the second portion comprising an inlet for sealing with and receiving fluid from the neck of the first portion, the second portion further comprising an engagement mechanism in or extending through the inlet, the engagement mechanism being arranged to displace the bung relative to the neck to allow fluid to flow through the neck and to subsequently replace the bung to reseal the neck, wherein the engagement mechanism is arranged to engage and lock with the bung prior to the engagement mechanism displacing the bung relative to the neck to allow fluid to flow through the neck.O 2. A fluid coupling as claimed in claim 1 wherein the engagement mechanism is (r) arranged such that the action of moving the first and second portions of the coupling CD together causes the neck to seal with the inlet prior to the engagement mechanism displacing the bung from the neck, with a subsequent action of moving the first and second portions of the coupling apart, causing the engagement mechanism to replace the bung in the neck and reseal the neck prior to the seal between the neck and the inlet being broken.3. A fluid coupling as claimed in claims 1 or 2 wherein the engagement mechanism displaces the bung relative to the neck in a direction away from the second portion of the coupling and replaces the bung by drawing the bung relative to the neck in a direction towards the second portion.4. A fluid coupling as claimed in any preceding claim wherein the bung has an outer face, facing towards an open mouth of the neck, the outer face of the bung being shaped to permit the engagement mechanism to engage with the outer face and hold the bung.5. A fluid coupling as claimed in claim 4 wherein the coupling has a longitudinal axis and the engagement mechanism comprises a plurality of arms extending generally in the direction of the longitudinal axis towards the first portion of the coupling, the second portion of the coupling further comprising a locking member arranged such that it adopts a first position relative to the arms as the two portions of the coupling are brought together, the locking member in the first position permitting: the two portions of the coupling to be brought together; a seal to be made between the neck of the first portion of the coupling and the inlet of the second portion of the coupling; and the arms to contact, or almost contact the bung, wherein continuing to move the first and second portions of the coupling closer together, causes the locking member to move to a second position relative to the arms, where the locking member extends the arms in a O substantially radial direction so that they engage and hold the bung, wherein continuing to (r) move the first and second portions of the coupling further together causes the bung to be CD displaced in the neck away from the second portion of the coupling.6. A fluid coupling as claimed in claim 5 wherein subsequently moving the first and second portions of the coupling apart causes the bung to be moved by the engagement mechanism to reseal the neck, with subsequent continued movement causing the locking member to release the arms from engagement with the bung and then causing the neck to move in an axial direction away from the inlet, breaking the seal between the neck of the first portion of the coupling and the inlet of the second portion of the coupling.7. A fluid coupling as claimed in claims and 6 wherein the second portion of the coupling comprises: a main body to which the locking member is fixed; a clip comprising the plurality of arms slideably mounted in the axial direction relative to the main body; a first biasing means biasing the clip to an extended position in the axial direction relative to the main body, in use towards the first portion of the coupling; a connector slideably mounted in the axial direction relative to the main body having the inlet on a face of the connector distal to the main body; and a second biasing means biasing the connector in the axial direction relative to the main body, in use towards the first portion of the coupling, wherein: the second biasing means is arranged to permit the inlet to receive the neck of the first portion and seal with the neck prior to the second biasing means permitting the connector to move axially with the neck until the arms come into contact with, or nearly come into contact with, the bung with the arms and clip being held in the extended position by the first biasing means, the first biasing means then permitting the arms and sa) 15 clip to move axially with the neck relative to the main body and the locking member, causing the locking member to force the arms into engagement with the bung and hold (r) the bung.8. A fluid coupling as claimed in any one of claims 5 to 8 wherein the main body, connector and clip are generally tubular and coaxially arranged one in side of the other, with the locking member extending coaxially within the clip.9. A fluid coupling as claimed in any one of claims 5 to 8 wherein: the outer face of the bung has a circumferential rim with a recess on a radially inward facing surface of the rim and the arms are arranged to be expanded radially by the locking member, when in the second position, to lock the arms into the recess of the bung.10. A fluid coupling as claimed in any one of claims 5 to 9 wherein the locking means is resilient and in the second position resiliently engages the arms to act to retain the arms axially in position relative to the locking member until a force is applied to the first and second portions of the coupling acting to axially separate them, which force is sufficient to overcome the resilience of the locking member to permit the locking member to move axially relative to the arms away from the second portion of the coupling to permit the arms to release the bung.11. A disposable container for use with a coupling as claimed in any preceding claim, wherein the first portion of the coupling comprises a straw of the container.12. A disposable container as claimed in claim 11 comprising only the straw, a membrane heat welded or otherwise sealed to the straw and a fluid to be dispensed.cr) 13. A dispenser comprising a coupling as claimed in any preceding claim, the dispenser 1- further comprising a housing having the second portion of the coupling mounted thereto a) 15 and a container, the container having the first portion of the coupling in the form of a 0 straw of the container, wherein the dispenser has an intended upright orientation and (r) when in the upright orientation the second portion of the coupling is located below the CD first portion of the coupling, with a longitudinal axis of the coupling aligned vertically and with the inlet of the second portion of the coupling facing vertically upwards.14. A dispenser as claimed in claim 13 comprising means for engaging the first portion of the coupling to locate it and to move the first and second portions axially together along a substantially vertical axis.15. A dispenser as claimed in claim 13 or 14 wherein the container may be removed prior to being empty without spillage, with any residual fluid in the coupling being retained in the second portion of the coupling.16. A coupling substantially as hereinbefore described with the reference to, or as illustrated in, one or more of the accompanying figures.17. A dispenser substantially as hereinbefore described with reference to, or as illustrated in, one or more of the accompanying figures.