GB2157783A

GB2157783A - Beer keg valve

Info

Publication number: GB2157783A
Application number: GB08410130A
Authority: GB
Inventors: Roger John Hyde
Original assignee: Alumasc Ltd
Current assignee: Alumasc Ltd
Priority date: 1984-04-18
Filing date: 1984-04-18
Publication date: 1985-10-30
Also published as: GB8410130D0; GB2157783B

Abstract

A poppet valve for a gas- pressurized beverage vessel 16 has a cup 10 housing the valve and for mounting within the neck 12 of the vessel. A resiliently deformable sealing ring 46 has an elliptical cross-section and is arranged around a tubular stem 30 with the ellipse major axis radially of the stem; a spring-loaded support 48, 50 is provided for the sealing ring. <IMAGE>

Description

SPECIFICATION Valve This invention relates to a valve for a gas pressure dispensed, beverage vessel such as a beer cask or keg.

Whilst there are many different designs of such valves, one type known as a "poppet" valve generally comprises: a cup housing the valve and for mounting within the neck of the vessel, the inner periphery of the cup mouth being formed as a first, downwardly-directed valve seat; a tubular stem, co-axially located in the cup, and having a port or ports through the wall at the upper end portion of the stem; a cap closing the upper end of the stem and presenting around the stem a second, downwardly-directed valve seat; a resiliently deformable sealing ring around the stem; and a spring-loaded support for the ring; the valve being closed when the sealing ring is urged upwardly against the valve seats by the spring-loaded support and open when the ring is forced by a valve-opening member down the stem below the port or ports.This type of poppet valve has the advantage that the necessary seal between the ring and the stem when the vale is open is not against a valve seat on the stem but generally against the stem wall; thus permitting a measured of tolerance for the length of normal operational opening of the valve. The shapes of the first and second valve seats and of the crosssection of the sealing ring are complicated and hence expensive, one example being shown in our European Patent Specification No. 0056295 and another in United Kingdom Patent Specification No. 211 7071A.

It is an object of the present invention to provide a simplified, but still effective, design of poppet valve for a gas-pressure dispensed, beverage vessel.

According to the present invention, in a poppet valve for a gas-pressure dispensed, beverage vessel as described above, the sealing ring has an ellipitical cross-section and is arranged with the ellipse major axis radially of the stem so that the outer and inner margins of the upper surface of the ring seal against said first and second valve seats respectively, when the valve is closed, and the inner peripheral surface of the ring seals against the stem wall, when the valve is open.

At first sight, it may seem that a simple 0ring would suffice but we have discovered that such an O-ring does not adequately and consistently seal against the first and second valve seats.

In an embodiment of the invention, the stem is an integral extension of the extractor or down tube, the upper end of the tube being closed by a welded cap, the stem diameter being reduced at the upper end portion so that the sealing ring can pass the ports with clearance.

The above and other features of the invention are shown, by way of example, in the Drawing of an axial section of a valve in both closed and open positions.

As shown, a valve housing cup 10 is screwed into the neck 1 2 that it welded about the bung hole 14 of a cask or keg 16. An 0ring seal 1 8 is trapped between a radially inwardly directed flange 20 of the neck 1 2 and a radial shoulder 22 on the cup 1 0. A radially outwardly extending flange 24 is welded about the mouth 26 of the cup 10 which is shown to curve generally, radially inwardly so that the diameter of the mouth is smaller than that of the cup itself. The inner periphery of the cup mouth is chambered to form a downwardly-directed valve seat 28.

A stem 30 of formed tubing is located within the cup 10 by means of a radial flange 32 welded to the tube and trapped between a radial shoulder 34 in the ported skirt 36 that depends from the cup 10 and a circlip 38.

The stem extends downwardly to form the extractor or down tube by which beverage is dispensed from the keg. The upper end portion of the stem 30 has a reduced diameter, has a series of ports 40 punched through the stem walls and is closed by a welded-on cap 42 that flares upwardly and outwardly away from the tube end. The cap is chamfered to present a downwardly-directed valve seat 44 around the stem.

A sealing ring 46 of resilient-deformable material and an elliptical cross-section is arranged around the stem with the ellipse major axis radially of the stem. The sealing ring is supported by an annular washer 48 and is loaded by a helical spring 50 compressed between the support member 48 and the radial flange 32 on the stem.

The valve is normally closed (as shown by the left-hand side of the figure), the spring 50 urging the support washer and sealing ring upwardly so that the outer and inner margins of the ring's upper surface respectively seal against valve seats 28 and 44; whilst having a clearance between the inner periphery of the ring and the stem ports. When the valve is opened, by the central column 52 of a conventional dispense head (not shown) the sealing ring is forced down the stem, past the ports 40, to encounter the larger diameter of the stem proper; the inner peripheral surface of the ring sealing against the stem wall (as shown by the right hand side of the figure). At the same time, the upper surface of the ring seals against the mouth of the column 52 to prevent gas, that is delivered about the column 52 through the cup 10 and out through the ports in the cup's skirt 36, from leaking through to the dispense pipe and stem 30.

Trials with conventional O-ring seals have shown these to be liable to failure, one reason being that the O-ring tends to be forced up through the annular space between the cup mouth and the stem cap. The elliptically sectioned sealing ring of the present invention has been shown to provide a better, more consistent seal in both the closed and the open positions of the valve.

Claims

1. A poppet valve for a gas-pressure dispensed, beverage vessel comprising: a cup housing the valve and for mounting within the neck of the vessel, the inner periphery of the cup mouth being formed as a first, downwardly-directed valve seat; a tubular stem, co-axially located in the cup, and having a port or ports through the wall at the upper end portion of the stem; a cap closing the upper end of the stem and presenting around the stem a second, downwardly-directed valve seat; a resiliently deformable sealing ring having an elliptical cross-section and arranged around the stem with the ellipse major axis radially of the stem; and, a spring-loaded support for the sealing ring; the valve being closed when the sealing ring is urged upwardly by the spring-loaded support so that the outer and inner margins of the upper surface seal against said first and second seats respectively and open when the ring is forced by a valve-opening member down the stem below the port or ports, the inner peripheral surface of the ring sealing against the stem wall.

2. A valve as claimed in claim 1, wherein the stem is an integral extension of an extractor or down tube for the vessel, the upper end of the stem being closed by a welded cap.

3. A valve as claimed in claim 1 or claim 2, wherein the stem diameter is reduced at the upper end portion so that the sealing ring can pass the port or ports with clearance.

4. A poppet valve for a gas-pressure dispensed, beverage vessel substantially as described with reference to or as shown by the Drawing.