The invention relates to kegs for housing fluid and in particular to improvements in so called fittings for such kegs which fittings house a valve which operably enables ingress and egress of fluid in and out of the keg. The keg is used throughout to refer generally to containers for fluids.
It is known to provide many different types of fittings for kegs wherein the fitting principally comprises an upper flange for attachment to a connector at the end of a feed line from a supply of fluids such as beer during loading, or to a dispensing tap such as in a public house during use.
The valve generally comprises a rubber (or other elastomeric material) seal which is urged against a seat on the inside face of the upper flange by a coiled spring which reacts against a housing for the spring, which housing is connected to the flange.
However, in known keg fittings, the arrangement of the flange and housing is relatively complex requiring considerable machining of parts and number of components. The invention seeks to provide a simplified fitting over the known art and in particular a relatively easy to manufacture fitting which is relatively easy to attach to a keg. Moreover, it is sometimes known for the valve seal sometimes to incorrectly locate against the valve seat. The prior art tries to mitigate this problem by providing a relatively long guide in the flange adjacent the valve seat for directing the valve seal into position. Nevertheless, problems are known to occur and the invention seeks to mitigate such problems.
EP-A-25682 discloses a valve fitting in accordance with the preamble of Claim 1.
According to the invention, as defined in claim 1, there is provided a valve fitting for a keg of fluid, comprising a substantially flat upper flange adapted for attachment to a neck of the keg at a first annular part which upper flange comprises an aperture, and a support arrangement for co-operating with a biasing device such as a spring to urge a valve seal against a valve seat provided on the inside of the upper flange adjacent the aperture, and characterised in that the support arrangement comprises at least two legs which depend from the upper flange from a separate and radially inward position with respect to the first annular part thereby to position the support arrangement radially inwardly of the keg neck in use.
Preferably the flange and support arrangement are integrally formed. Preferably the upper flange is adapted to weld to the upper rim of a keg neck.
Preferably the support arrangement comprises a lower ring for co-operating with the spring. The ring can be cup shaped thereby to seat the circular end of a helical spring within the arrangement. Preferably the support arrangement comprises more than two legs extending between a flange and lower ring. Preferably the legs are adapted to guide the valve seal in an axial manner during opening and closing of the valve. In a preferred form three legs are provided.
Preferably the flange comprises a seal guide proximal the valve seat. Preferably the depth of the seal guide is less than 50% of the thickness of the valve seal. Preferably the depth of the seal guide is in the order of the thickness of the bulk of the flange body. Preferably the depth of the guide is in the order of 3 mm.
Preferably, the major element and/or percentage of reactive force against the biaising means (ie. in opposition to the force urging the seal against the valve seat) is relayed via the fitting through to the keg. Preferably, the fitting comprises a support arrangement for co-operating with the spring (or biaising device) which support arrangement is only connected to a flange fitting in the valve fitting for attachment to the container.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Referring to Figure 1 there is shown a keg K for housing pressurised fluid such as beer. Keg K comprises a top wall T having a central aperture in which is mounted a fitting F enabling the ingress and egress of fluid into and out of the keg K. Fitting F comprises an upper flange to which a connector is clamped during filling and emptying operations. Fitting F further comprises a spring S for urging a valve seal against a valve seat in the under side of the upper flange. The spring S is supported by a support arrangement A. Alternatively, the spring is supported on lugs which extend radially from downtube D proximal the lower end of support arrangement A as described later. Fitting F further comprises a downtube D to assist in siphoning fluid out of keg K during use.
Referring more particularly to a first embodiment of a fitting F according to the invention there is shown in Figures 2 and 3, a fitting F attached to a neck 10 in the top wall T of a keg K, which neck 10 is formed by deep drawing the top wall T of the keg into a somewhat hollow frusto-conical shape providing an upper rim 12 against which fitting flange 14 can be attached in use. For example flange 14 can be attached to rim 12 using a rebated annulus 16 which can be welded to the rim 12. In another form annulus 16 and rim 12 can comprise co-operating threading for example.
Flange 14 comprises an outer rim 18 for co-operation with a connector on a feed or outlet pipe. Flange 14 further comprises a central aperture 20 to allow ingress and egress of fluid to and from the keg K which aperture 20 has a valve seat 22 about its periphery. Flange 14 also provides a valve seal guide 24 adjacent seat 22 to assist in locating a valve seal against seat 22 in use.
Depending from flange 14 is a spring support arrangement consisting of three legs 26 which in this embodiment extend away from seal guide 24. At the lower end of legs 26 there is provided a ring or cage base 28 which in this embodiment is cup shaped and comprises a lip 30 for locating a coiled spring S. Support arrangement A further comprises an aperture 32 for passing downtube D into the bottom of the keg K. Alternatively, radially protruding lugs can be provided on a downtube D for contacting ring 28 on the underside. The upper side of the lugs on downtube D can be used to engage the lower end of coil spring S such that the reactive force of spring S which urges a valve seal to engage valve seat 22, is conveyed through to support arrangement A via the lugs on the downtube D. This arrangement is shown in Figure 6 described later.
In use, a downtube D or centrepiece is located within fitting F below aperture 20 down through aperture 32 into the bottom of keg K. A spring S is provided between base 28 and flange 14 which spring carries at its upper end an annular seal adapted to engage on its inside edge with the downtube D and on an outer edge with annular seat 22 in flange 14. By attaching a connector to flange 14, it is possible to manipulate the valve by causing spring S to move axially away from upper aperture 20 thereby causing the valve seal to move away from seat 22 and enable ingress and/or egress of fluid to or from the keg. When allowing the valve to close, the spring S urges the valve seal towards seat 22 and beneficially legs 26 act to guide the valve seal axially towards aperture 20. This guiding action is further assisted by annular guide 24 surrounding seat 22.
Referring to Figures 4 and 5 there is shown a second embodiment of a fitting F according to the invention wherein the fitting comprises like components with the fitting shown in Figures 2 and 3 which are accordingly labelled using the same two digit reference number prefixed with the digit 1. However, in this arrangement an open ended cylindrical neck 110 is provided having a rebated lower end for engaging the rim of the aperture provided in the centre of a substantially flat top wall T of a keg. The rebated lower end 111 of neck 110 can for example be welded into the aperture and top wall T. Similarly, the upper end 112 can be connected to flange 114 as described earlier. Thereafter, fitting F shown in Figures 4 and 5 has like components such as legs 122 and spring support arrangement base 128 identical to that shown in the first embodiment.
Accordingly, once fitted to a keg, the operation of filling or emptying a keg using a fitting F housing a suitable valve spring and downtube components is the same as described earlier.
Beneficially, the length of legs 26 and/or 126 can protrude beyond the lower edge of top wall T for example by a distance of more than 20 mm. Further, there is no need to provide any obstructions to fluid flow between legs 26 and base 28 and the inside wall of the top of the keg thereby providing a large cavity about the valve and spring arrangement for the ingress and the egress of fluid into and from the keg.
Referring to Figure 6 there is shown part of a downtube D for passing through aperture 32 (or 132) in a fitting F according to the invention. As can be seen from the exploded view, the downtube forms a centrepiece in the arrangement wherein spring S is passed over the upper part of the downtube such that the lower end of spring S contacts some radially protruding lugs L which can be provided with a suitable curved recess for engaging the lower edge of spring S. The underside of lugs L engages the upper surface of ring 28 (or 128) of the earlier embodiments thereby to locate the centre-piece in position. Additionally, a lower set of protruding lugs L can be provided for engaging the underside of cage 28 (or 128) thereby better to locate downtube D in position. The lower set of lugs L can be passed through slots such as slots 33 in ring 28 forming part of the premature of aperture 32. Additionally, a slot 40 can be provided in this shoulder arrangement which forms the series of lugs L in order to engage a downwardly protruding tip 42 at the end of spring S. Finally, at the top of spring S there is provided a cup C in which is located a valve seal VS which is operably urged against valve seats 22 (or 122).