Keg closure with venting mechanism

Abstract

A closure (10) for use with a beverage keg (20) is disclosed. The closure (10) comprises an inlet, a barrier (1) and a housing (2) that defines a venting hole (11). The barrier (1) seals the venting hole (11). The closure (10) comprises an unvented configuration in which a keg to which the closure is fitted can be pressurized. The closure (10) also comprises a vented configuration in which the barrier (1) is unsealed from the venting hole (11) to permit depressurization of the keg (20).

Claims

1. A closure for a beverage keg, the closure comprising a housing defining: an inlet for admitting a pressurised gas into a headspace of a beverage keg; and a venting hole separate from the inlet, the venting hole communicating with a gas vent path between the headspace of the keg and an exterior of the closure; the closure further comprising a barrier for sealing the venting hole; wherein, when fitted to the keg, the closure is configured to be switchable from: an unvented configuration in which the barrier seals the venting hole so that the closure is able to retain a pressurised gas within the keg; to a vented configuration in which the venting hole is no longer sealed by the barrier so that a pressurised gas in the headspace of the keg can escape along the gas vent path via the venting hole to the exterior of the closure; thereby permanently depressurising the keg, wherein the barrier is engaged to the housing defining the venting hole when the closure is in the unvented configuration, and the barrier is arranged to be dislodged from its engagement with the housing defining the venting hole so as to switch the closure to the vented configuration.

2. The closure of claim 1, wherein the barrier is a discrete member which, when dislodged, separates from the housing defining the venting hole, and further comprises a retention portion for retaining the barrier to the closure when the closure is in the vented configuration, and the barrier is unsealed from the venting hole.

3. The closure of claim 1, wherein at least one of the barrier and housing defining the venting hole are shaped to restrain the barrier against movement in an outward direction towards the exterior of the closure.

4. The closure of claim 3, wherein the barrier and housing defining the venting hole are tapered relative to one another so as to restrain the barrier against movement in the outward direction toward the exterior of the closure.

5. The closure of claim 1, further comprising a venting member arranged to act on the barrier to dislodge the barrier from the venting hole thereby to switch the closure from the unvented to the vented configuration.

6. The closure of claim 5, wherein at least a portion of the venting member is arranged to fit within the venting hole, and wherein the portion of the venting member that is arranged to fit within the venting hole defines a conduit shaped and arranged to permit gas released during depressurisation of the keg to flow through the venting hole.

7. The closure of claim 5, wherein the venting member is arranged to drive the barrier in an inward direction away from the exterior of the closure, and in towards the gas vent path.

8. The closure of claim 5, wherein the venting member comprises a drive member for transmitting a manually-applied force to the barrier.

9. The closure of claim 5 further comprising at least one latch member arranged to be movable between: a latched position at which the latch member blocks movement of the venting member preventing the venting member from acting on the barrier; and an unlatched position at which the venting member is free to move to a position at which the venting member can act on the barrier to unseal the venting hole.

10. The closure of claim 9, wherein the at least one latch member is biased towards the latched position.

11. The closure of claim 1, further comprising at least one ratchet formation that locks the venting member at a position at which the venting member has acted on the barrier to unseal it from the venting hole.

12. The closure of claim 11, wherein the at least one ratchet formation is integrally-formed with the venting member.

13. The closure of claim 1, further comprising a valve element for opening and closing the inlet.

14. The closure of claim 13, wherein the first valve element is biased towards a closed position.

15. The closure of claim 13, further comprising an outlet through which a beverage may be extracted from the keg to which the closure is fitted.

16. The closure of claim 15, wherein the valve element is for opening and closing the outlet of the closure.

17. The closure of claim 15, further comprising a dip-tube positioned so that when the closure is fitted to a keg, a fluid flow path extends between the outlet of the closure and an internal base region of the keg.

18. The closure of claim 15, wherein the closure is arranged to receive a pressurised gas via the inlet and to dispense beverage from a keg to which the closure is fitted via the outlet when in the unvented configuration.

19. A keg, supplied or fitted with a closure of claim 1.

20. A method of controlling the pressurisation of a beverage keg, the method comprising: fitting a closure to the keg, the closure defining a venting hole communicating with a gas vent path between a headspace of the keg and an exterior of the closure, the closure being provided with a barrier to seal the venting hole so as to retain a pressurised gas within the keg; and dislodging the barrier from the venting hole to permanently depressurise the keg.

21. A method of improving the safety of a draught beverage keg comprising: fitting a closure to the keg, the closure comprising a venting hole and being in an unvented configuration in which the venting hole is sealed by a barrier and thereby the closure is able to retain a pressurised gas within the keg; filling the keg with beverage to be dispensed on draught; transporting the filled keg to a dispensing location; injecting a pressured gas into the keg to dispense beverage from it; and after dispensing of beverage: permanently depressurising the keg by switching the closure from the unvented configuration to a vented configuration by dislodging the barrier from the venting hole.

Description

(1) In order that the invention may be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which:

(2) FIG. 1 is a perspective exploded view of a closure according to a first embodiment of the present invention, to be fitted to the neck of a plastics keg;

(3) FIG. 2 is a side view of the closure of FIG. 1 fitted to the keg, the closure being in an unvented configuration;

(4) FIG. 3 is a top plan view of the closure and keg of FIG. 2;

(5) FIG. 4 is a cross-sectional view of the keg and closure of FIG. 3, the cross-section being taken along section plane A-A that bisects the keg and closure and intersects a central longitudinal axis shared by the keg and closure;

(6) FIG. 5 corresponds to FIG. 4 but shows the closure in a vented configuration;

(7) FIG. 6 is a perspective view from above and one side of the closure of FIG. 1, the closure being shown here in isolation from a keg, with the closure being in an unvented configuration;

(8) FIG. 7 is a perspective view from below and one side of the closure of FIG. 6;

(9) FIG. 8 is a further perspective view from below the closure of FIG. 6;

(10) FIGS. 9 to 11 correspond to FIGS. 6 to 8 respectively but show the closure when in a vented configuration;

(11) FIG. 11a shows a front perspective view of a push button of the closure of FIG. 1, the push button being shown in isolation from the closure.

(12) FIG. 11b shows a reverse perspective view of the push button of FIG. 11a.

(13) FIG. 12 is a perspective view from above and one side of a closure according to a second embodiment of the present invention, the closure again being shown in isolation from a keg, with the closure being in an unvented configuration;

(14) FIG. 13 is a perspective view from below and one side of the closure of FIG. 12;

(15) FIG. 14 is a further perspective view from below the closure of FIG. 12;

(16) FIGS. 15 to 17 correspond to FIGS. 12 to 14 respectively but show the closure when in a vented configuration.

(17) FIG. 17a shows a reverse perspective view of the closure of FIG. 12, the push button being shown in isolation from the closure.

(18) The embodiments of the present invention relate to a keg closure corresponding functionally and in key dimensions with existing keg closures known in the art as Flat Type, Type A or Flat Type A keg closures. As such, standard dispensing or filling heads suitable for use with such Flat Type A keg closures can also be used in conjunction with the closure of the first and second embodiments of the present invention.

(19) FIGS. 1 to 11b relate to the first embodiment of the present invention and FIGS. 12 to 17a relate to the second embodiment of the present invention. The same reference numerals are used to refer to similar features in these embodiments. In particular, each show a closure 10 adapted to be push-fitted to the neck 8 of a keg 20, the closure 10 having components that allow the keg 20 to be vented after use for safe disposal of the keg 20, the vented state of the keg being clearly indicated by the closure 10.

(20) The components of each closure 10 are made predominantly of injection-moulded plastics materials such as polyester, polyolefin, polyamide or the like. The keg is formed from PET, stretch blow-moulded from a preform. It is emphasised that the materials used for the keg 20 and the closure 10 and their methods of manufacture are merely preferred and are not essential to the broad inventive concept.

(21) A closure 10 according to the first embodiment of the present invention will now be described in more detail with reference to FIGS. 1 to 11b. Referring firstly to FIGS. 1 to 3, the closure 10 comprises a barrier in the form of a rubber bung 1, a generally annular housing 2, a venting member in the form of a push button 3, an annular seal 4, a valve mechanism 5, a coil spring 6 and a basket 7.

(22) The annular seal 4, the valve mechanism 5 and the coil spring 6 share many features in common with the aforementioned previously-known keg closures. In particular, they allow movement of a valve element to open and close concentric flow paths to allow the keg 20 to be filled with beverage, and also allow dispensing of beverage from the keg 20.

(23) For example, during dispensing, a dispense head is fitted to the closure 10 and operated to open the valve element of the valve mechanism 5. Accordingly, the concentrically-outermost flow path allows pressure to be introduced into a headspace 21 internal to the keg 20 thereby allowing a beverage such as beer to be dispensed under super-atmospheric pressure from the concentrically-innermost flow path which is in communication with a dip-tube 29.

(24) It should be noted that FIG. 1 does not show the whole of the keg 20 and the dip-tube 29. However, it will be appreciated that the upper end of the dip-tube 29 connects to the underside of the valve mechanism 5 (as shown in FIGS. 4 and 5), and the lower, open end of the dip-tube 29 is positioned at a lowermost position within the keg 20. This ensures that substantially all the beverage within the keg 20 can be drained from it. Accordingly, the closure 10 together with the dip-tube 29 defines a fluid flow path that extends between the outlet and a lowermost position of the keg.

(25) For the avoidance of doubt, the keg 20, the dip-tube 29 and certain features of the closure are similar to those described in International Publication Number WO2007/064277 the contents of which are hereby incorporated by reference.

(26) After dispensing of beverage, when a dispense head is removed from the closure 10, the valve mechanism 5 automatically closes the valve element. Accordingly, this super-atmospheric pressure remains inside the keg 20. Some of the remaining components of the closure 10, in particular the bung 1 and the push button 3, cooperate to define a safety mechanism that allows this pressure to be vented to allow safe disposal of the keg 20 after use as will be described in greater detail below.

(27) The closure 10 and keg 20 have complementary engagement structures which allow the closure 10 to be push-fit onto the keg 20. In the present embodiment, the complementary engagement structures include a circumferential flange 28 on the neck 8 of the keg 20, and a complementary snap-ring 18 on the closure. During push-fitting of the closure 10 to the keg 20, the snap-ring 18 is arranged to snap-fit into place underneath the circumferential flange 28. Advantageously, in contrast with other screw-thread arrangements, such a snap-fit connection between the closure 10 and the keg 20 can more easily be automated and also provides a more reliable and tamper-proof engagement between the closure 10 and keg 20.

(28) FIG. 4 shows a sectional view of the closure 10 in an unvented configuration, the bung 1 being at a position sealing a venting hole 11 defined in the wall of the housing 2. The bung 1 is positioned adjacent to the push button 3. The push button 3 is slidable in a radially-inward direction towards the bung 1 along a channel 13 which is also defined in the sidewall of the housing 2. The bung 1 and the venting hole 11 are shaped to restrain the bung 1 against movement in an outward direction away from the interior of the closure 10. This is by virtue of an enlarged inwardly-directed head of the bung 1 and a slight relative tapering between the bung 1 and the venting hole 11.

(29) FIG. 5 shows the same view as FIG. 4, but with the closure 10 in a vented configuration. As the closure 10 is switched from the unvented configuration of FIG. 4 to the vented configuration of FIG. 5, the push button 3 displaces the bung 1 from the venting hole 11. Specifically, a drive member in the form of a rod portion 16 of the button 3 extends through the venting hole 11 to drive the bung 1 in a radially-inward direction unsealing it from the venting hole 11. The bung 1 thereby detaches from the venting hole 11 defined in the housing 2 and falls into the basket 7.

(30) As can be seen clearly in FIGS. 10 and 11, holes in the basket 7 are sized to ensure that the bung 1 cannot fall through them and into the keg. Thus, the basket 7 together with the other internal structures of the closure 10, define a retention portion in the form of a cage that retains the bung 1 to the closure, preventing the bung 1 from falling into the beverage, potentially spoiling it or introducing a choking hazard to a consumer of the beverage.

(31) The opening of the venting hole 11 ensures a gas can flow along a gas vent path between the headspace 21 of the keg 20 and the environment external to the keg 20 and closure 10. Accordingly, if there is super-atmospheric gas remaining in the keg 20, this will be vented through the venting hole 11. Specifically, gas is able to pass from the headspace 21, via holes in the basket 7 into an annular chamber defined between the housing 2 and the valve mechanism 5 and through the venting hole 11 communicating with that chamberthe gas flowing around the outside of the rod portion 16.

(32) Moreover, although the rod portion 16 is inserted into the venting hole 11, the rod portion 16 defines a conduit through which the gas being vented can flow. This can be more clearly seen in FIG. 11b. The rod portion 16 of the push button 3 has a frustoconical tip with an end-surface 16a which contacts with the bung 1 when the closure 10 is being switched from the unvented to the vented configuration. The rod portion 16 also comprises a pair of indents 16b. These, together with the taper of the frustoconical tip define said conduit.

(33) It will be noted that the end-surface 16a which contacts with the bung 1 is far smaller than the region of the push button 3 that a user pushes. Accordingly, the manually-applied force of the user can be easily transferred to the bung 1 to dislodge it.

(34) As the bung 1 falls away from the venting hole 11, the effect of pressing the push button 3 to depressurise the keg 20 is permanenti.e. whilst the closure is fitted to the keg, it is not possible to repressurise the keg 20 once the push button 3 has been pressed. Thus, the closure 10 is configured to switch irreversibly from an unvented configuration to a vented configuration.

(35) In view of this, it is desirable to prevent accidental or premature pressing of the button 3. To this end, the push button 3 comprises latch members in the form of a pair of jaws 32 integrally-formed with the push button 3.

(36) Referring to FIG. 2, the jaws 32 protrude vertically beyond the extent of the opening defined by channel 13 to block the movement of the push button 3 radially-inward towards the bung 1. The jaws 32 are disposed above and below the main body of push button 3, and are able to flex resiliently relative to the rest of the push button 3 to which they are attached. To enable the push button 3 to slide into the channel to vent the keg 20, a user must first squeeze the jaws 32 together to deflect them inward so they no longer extend beyond opening of the channel 13; only then can the push button 3 be driven into the channel 13 to displace the bung 1.

(37) Referring back to FIG. 1, the push button 3 also comprises a resilient pair of prongs 33 that have ratchet formations 33a at their tips. The ratchet formations 33a of the prongs 33 cooperate with a first outward pair of openings 14 and a second inward pair of openings 15 defined in the channel 13 to ratchet the push button 3 into the channel 13. In particular, during assembly, but before venting, the push button 3 is slid into the channel 13 so that ratchet formations of the prongs 33 lock into the first pair of openings 14. This retains the push button 3 in the channel 13, preventing it from moving radially outward from the channel 13 and so possibly falling out of the channel 13 during transit. As mentioned, and at the same time, the jaws 32 prevent the push button 3 from moving radially further into the channel 13.

(38) When moving the push button 3 inwardly to displace the bung 1 to switch the closure 10 from the unvented to the vented configuration, the ratchet formations 33a of the prongs 33 slide past the first pair of openings 14 and latch into the second pair of openings 15. The push button 3 thereby latches into a position where it is permanently recessed with the channel 13, providing a visual indication to a user that the closure 10 has been vented, and the keg 20 can safely be disposed. Furthermore, the user is provided with a tactile and audible cue that the closure 10 has been latched into the vented position when the prongs 33 spring out and their ratchet formations 33a click into place within the openings 14.

(39) FIGS. 12 to 17a show a closure according to the second embodiment of the present invention, the main difference over the first embodiment being the shape of the push button 3. Here, the push button 3 has a chamfered profile, with a ramped upper surface. Unlike the first embodiment, the upper surface does not consist of a jaw; only the lower surface of the push button 3 supports a jaw 32a. This configuration reduces the profile of the closure 10 and simplifies its operation. Furthermore, the closure of the second embodiment allows one of the user's fingers to operate the jaw 32a on the lower surface of the push button 3 whilst an opposing finger on the ramped upper surface of the push button 3 simultaneously provides a reaction force to enable the jaw 32a to be squeezed upwardly while pushing the push button 3 in a radially-inward direction to vent the keg 20.