WO2006021753A1

WO2006021753A1 - Valve fitting for a keg

Info

Publication number: WO2006021753A1
Application number: PCT/GB2005/003234
Authority: WO
Inventors: Kenneth Leonard Simpson
Original assignee: Spears Limited
Priority date: 2004-08-24
Filing date: 2005-08-19
Publication date: 2006-03-02
Also published as: EP1796999A1

Abstract

The invention concerns a valve fitting (1;30) for a keg used for the storage of liquids under pressure, the valve fitting being of the kind known as a well type spear: .The valve fitting includes a body (2;2') having an opening (3) therethrough with a body valve seat (5) around the opening, a tube (11) with a fluid path therethrough an upper portion of which is located within the centre of the body opening (3) and which is moveable axially relative to the body (2;2') to open and close a first valve, and a main seal element (18) secured to the top of the tube (11) and providing a seal surface to co-operate with the body valve seat (5) to seal the first valve. The valve fitting (1;30) further includes a valve member (17;32) located within the upper portion of the tube (11) which is moveable axially relative to the tube (11) to open and close a second valve, and a valve seat (19;34) within the upper part of the tube (11) with which the valve member (17;32) co-operates to seal the second valve. The valve fitting 1;30) is assembled through the opening (3) in the body (2;2'). The valve fitting (1;30) further includes a washer (22;22') located on the top of the main seal element (18), the washer (22;22') having a diameter greater than the diameter of the opening (3) in the body (2;2') and the washer (22;22') and/or the body (2;2') are specifically adapted to permit the washer (22;22') to pass through the opening (3) in the body (2;2’).

Description

Title: Valve fitting for a keg

Description of Invention

This invention relates to a valve fitting for a keg of the kind generally used to store beer or other liquids under pressure. The valve fitting is of the kind referred to within the trade as a well type spear and in use may be permanently secured to the keg, typically by welding, or removably secured to the keg by appropriate means such as a screw thread or circlip.

Such well type spears comprise a body, and located within an opening in the body are other components of the valve fitting the top surfaces of which are recessed into the body, hence what is known as a "well type" spear. The other components of the spear include a tube which is located in the centre of the opening in the body and which extends to a point close to but not at the bottom of the keg. The valve fitting includes two valves, a first to control flow through the opening in the body around the top of the tube, and a second to control flow through the tube itself.

When the keg is full and liquid is dispensed the first valve admits pressurised gas which forces liquid up the tube, through the second valve, and thus out of the keg. When the keg is empty and to be filled, it is turned upside down and the liquid is forced in through the first valve while the gas in the keg is forced down the tube, out of the second valve, and out of the keg. The particular construction of the body, and in particular the shape of the opening in the body, is designed to minimise frothing of the liquid during filling of the keg, which enables rapid filling. However, as the present invention is' not concerned with this aspect of the valve fitting it will not be discussed further.

The valve fitting also includes a main seal element located on the top of the tube which seals around the opening in the body to close the first valve, and a spring which acts between the bottom of the body and the top of the tube to bias the tube upwards in the keg and thus to bias the first valve closed. A safety washer is provided on the top of the main seal element which is larger than the opening in the body and thus prevents the removable spear components being blown out in an accident.

The valve fitting also includes a valve member for closure of the second valve, this may be a second seal element which closes onto a valve seat at the top of the tube, or a rigid valve member which seals against the underside of the main seal element. In either case the valve member is biased upwards in the tube to close the second valve by a second spring acting between a formation in the tube and the underside of the valve member.

In the past most spears of this kind of general construction have been removably secured to the keg, meaning that they could be assembled from the bottom before being secured to the keg. Examples of such spears are described in US 6,367,660 B1 , GB 2072290 A and WO 03/093163 A1.

However, in some circumstances, such as when the body of the spear is welded to the keg the spear has to be assembled and disassembled from the top, through the hole in the body.

This requirement has led to problems as the traditional safety washer could not be included, and thus there has been a danger that, if the main seal element failed whilst the keg was pressurised, the other components including the tube, have been liable to fly out of the keg at high speed and cause injury to anyone nearby, or damage to items in the vicinity. The applicant's earlier European Patent, EP 1 003 687 B1 , provided one solution to this problem by including an alternative form of washer which could be inserted through the top and which prevented the spear components from being forced out of the body if the main seal element should fail. However, it was found that in spears made according to that patent the main seal element did not have as long a working life as is desirable, often suffering damage and leaking after a relatively short period.

It is an object of the present invention to provide a well type spear which seeks to address the above described problems.

According to a first aspect of the invention there is provided a valve fitting for a keg used for the storage of liquids under pressure, the valve fitting being of the kind known as a well type spear and including a body having an opening therethrough with a body valve seat around the opening, a tube with a fluid path therethrough an upper portion of which is located within the centre of the body opening and which is moveable axially relative to the body to open and close a first valve, a main seal element secured to the top of the tube and providing a seal surface to co-operate with the body valve seat to seal the first valve, a valve member located within the upper portion of the tube which is moveable axially relative to the tube to open and close a second valve, a valve seat within the upper part of the tube with which the valve member co¬ operates to seal the second valve, wherein the valve fitting is assembled through the opening in the body, characterised in that the valve fitting further includes a washer located on the top of the main seal element, the washer having a diameter greater than the diameter of the opening in the body, and the washer and/or the body are specifically adapted to permit the washer to pass through the opening in the body.

The washer may conveniently have a portion cut-away over a small part of the circumference to enable it to be passed through the valve seat in the body. The washer may have a portion cut from its periphery to provide a secant edge or a rounded notch cut in its periphery. Alternatively the periphery of the opening in the body may have a cut-away portion to enable the washer to be passed through the valve seat in the body. The periphery of the opening in the body may have two cut-away portions.

Preferably the periphery of the washer is in contact with the body valve seat when the first valve is closed.

The main seal element has an opening therethrough to provide a continuation of the fluid path through the tube, and preferably the washer includes a downwardly extending portion which fits into the opening in the main seal element and thereby covers the surface of the main seal element.

Preferably the valve seat within the upper part of the tube is provided on a lower surface of the main seal element.

The valve fitting further includes a main valve spring which biases the first valve closed the main valve spring which preferably has a plurality of tightly spaced coils at each end and a plurality of widely spaced coils in a central portion.

These and other features of the invention will now be described by way of example with reference to the accompanying drawings, of which:-

Figure 1 illustrates a first valve fitting according to the invention shown in (a) partial section exploded view and (b) partial section assembled view; Figure 2 illustrates a second valve fitting according to the invention shown in (a) partial section exploded view and (b) partial section assembled view;

Figure 3 illustrates a first safety washer for use in the valve fittings of

Figure 1 or 2 in (a) plan view and (b) section; Figure 4 illustrates a second safety washer for use in the valve fittings of Figure 1 or 2 in (a) plan view and (b) section; Figure 5 illustrates a spring for use in the valve fittings of Figure 1 or 2; Figure 6 illustrates a body of a third valve fitting according to the invention, and is shown in (a) plan view and (b) sectional view; and

Figure 7 illustrates a safety washer for use in the valve fitting of Figure 6.

Referring first to Figure 1 , a valve fitting 1 having a body 2 which in use is permanently secured to a keg (not shown), by means such as welding, such that the upper part 2a forms a neck upstanding from the keg and the lower part 2b is within the keg. The body 2 is generally cylindrical with an opening 3 through the middle thereof. The opening 3 in the upper part 2a provides a well 4, in which in use the connector (not shown) for extraction of the liquid is received, and at the base of the well 4 an inwardly extending angled valve seat 5. The narrowest part of the opening 3 is just above the valve seat 5. Below the valve seat 5, also in the upper part 2a of the body 2, opening 3 provides a chamber 6. The lower part 2b of the body comprises a plurality of legs 7 which connect a fluid diversion plate 38 and bottom cup portion 8 to the upper part 2a of the body, and which between them provide outlet apertures 9. The number of legs 7 and their width is minimised to maximise the total area of the outlet apertures 9. The cup portion 8 has an aperture 10 which completes the opening 3 through the body 2.

The fluid diversion plate 38 is curved rather than being flat to assist in non- turbulent diversion of the fluid through the outlet apertures 9 during filling of the keg. However, this form of fluid diversion plate 38 does mean that there are recesses 39 around the cup portion 8 which when the keg is cleaned before being refilled, which is undertaken with the keg inverted (as for filling) can trap the cleaning fluid or rinsing water. A plurality of drainage apertures 37 are therefore provided around the junction of the fluid diversion plate 38 to prevent this retention of cleaning fluid or water. The valve fitting 1 also includes a tube 11 which provides a flow path 12 therethrough. The tube 11 is of a first diameter A for most of it's length and of a wider diameter B in an upper portion 11a such that a ledge 13 is provided within the tube 11 at the base of the upper portion 11a. The upper portion 11a may be formed integrally with the rest of the tube as shown in Figure 1 or may be manufactured separately and the two parts joined together. The tube 11 is located within the opening 3 in the body, such that it passes through the aperture 10 in the cup portion 8, the upper portion 11a of the tube being a close but not tight fit in the aperture 10. The top of the tube 11 is flared outwardly to provide a Hp 14.

A main valve spring 15 is located around the upper portion 11a of the tube 11 between the cup portion 8 of the body 2 and the lip 14 at the top of the tube 11. A poppet valve spring 16 is located within the upper portion 11a of the tube 11 , resting on the ledge 13. A poppet valve member 17 is located on the top of the poppet valve spring 16, also within the upper portion 11a of the tube 11.

A main seal element 18 is located on the top of the tube 11. The main seal element 18 has a downwardly extending portion 18a which is a tight push fit into the top of the tube 11 , such that the main seal element 18 is retained in the top of the tube 11 and moves with it, and an upper outwardly extending portion 18b which extends outwardly over lip 14 at the top of the tube 11. The downwardly extending portion 18a provides an angled valve seat 19 for the poppet valve on the inner surface of its lower edge. The outwardly extending portion 18b provides a valve sealing surface 20 on its outer edge, this may be angled or radiused. It has been found that better sealing is achieved with a radiused valve sealing surface 20, as this ensures that the seal member 18 deforms when abutting the angled valve seat 5, rather than simply coming into contact with it. A step 21 is provided inwardly of the valve sealing surface 20. The main seal element 18 also has an opening 18c through the middle thereof, to provide a continuation of the fluid path 12 through the tube 11.

The valve fitting 1 also includes a safety washer 22 which is located on the top of the main seal element 18. The safety washer 22 has a downwardly extending part 22a which fits into the opening 18c in the main seal element

18, and an outwardly extending flange part 22b which fits across the top of the outwardly extending portion 18b of the main seal' element 18 to the step 21 , into which the edge 23 of the safety washer fits such that the edge 23 of the upper surface of the safety washer 22 is then continuous with the valve sealing surface 20.

The valve fitting 1 is assembled after the body 2 is welded to the keg, and therefore all the other components of the valve fitting 1 must pass through the body 2, and in particular through opening 3 just above the valve seat 5. The diameter of the safety washer 22 is greater than the diameter of the opening 3 in the body just above the valve seat 5, and thus once the valve fitting 1 is assembled the safety washer 22 cannot be forced out of the body and nor can any of the other components as they are retained below the safety washer 22. To enable the valve fitting 1 to be assembled, the safety washer 22 has a portion cut-away to reduce the diameter over a small part of the washer such that with care and a special tool it can pass through the opening 3 just above the valve seat 5. Alternative forms of safety washer 22 are illustrated in Figures 3 and 4. In Figure 3 the washer 22 has a secant edge 24, whilst in Figure 4 the washer 22 has a rounded notch 25.

Thus, as can be seen from Figure 1 b, when the valve fitting 1 is fully closed, i.e. both the first and second valves are closed, the edge 23 of the safety washer is in contact with a portion of the angled valve seat 5 and then the valve sealing surface 20 is in contact with a further portion of the angled valve seat 5, also the poppet valve member 17 is in contact with the valve seat 19. This means that the safety washer 22 covers the main seal element 18 such that none of the main seal element 18 is exposed to be damaged. The first valve can be opened by pushing the tube 11 down against the bias of spring 15, and when doing this the connector contacts the safety washer 22 rather than the main seal element 18, again preventing damage occurring. The second valve is opened by pushing the valve member 17 down within the tube 11 against the bias of the spring 16, and when doing this the connector cannot contact the main seal element 18 because the safety washer 22 is again covering it and protecting it.

As can be seen a safety washer 22 of this form and in this location provides a considerable improvement over the prior art, virtually preventing any damage to the main seal element and thus greatly prolonging it's working life. This in turn greatly reduces wastage and maintenance costs.

Referring now to Figure 2, an alternative embodiment of a valve fitting 30 according to the invention is illustrated. The body 2, main valve spring 15 and the safety washer 22 are identical to those described above with reference to Figure 1 , and thus are like referenced. The tube 11 is substantially the same ^■ as the tube 11 from Figure 1 , the only difference being that the upper portion 11a is shorter, but is like referenced in any event. The other components differ from those described with reference to Figure 1 and thus will now be described.

A poppet valve spring 31 is of a slightly conical form in order to operate effectively against a valve member 32 of different form. Also, as the valve member 32 is different, a main seal element 33 is also of modified form. It has a downwardly extending portion 33a which is a tight push fit into the top of the tube 11 , such that the main seal element 33 is retained in the top of the tube 11 and moves with it, and an upper outwardly extending portion 33b which extends outwardly over lip 14 at the top of the tube 11. The downwardly extending portion 33a provides a downwardly facing substantially flat valve seat 34 for the valve member 32 of the poppet valve on the bottom surface of its lower edge. The outwardly extending portion 33b provides a valve sealing surface 35 on its outer edge. A step 36 is provided inwardly of the valve sealing surface 35. The main seal element 33 also has an opening 33c through the middle thereof, to provide a continuation of the fluid path 12 through the tube 11.

The operation of the valve fitting 30 is as for the valve fitting 1 , with the same advantages over the prior art.

Referring now to Figure 5, an alternative from of main valve spring 15' is illustrated. It differs from the main valve spring 15 of Figures 1 and 2 in that, rather than having evenly spaced coils along it's length it has coils at either end which touch each other and very few widely spaced coils in between. This has been found to provide improved ease of assembly of the valve fittings 1 and 30, whilst still providing correct performance in the operation of the first valve.

The conventional main spring 15, as shown in Figures 1 and 2, is difficult to insert through the opening 3 of the body, and retain in position whilst the tube 11 is being inserted. To assist in assembly it is desirable to reduce the outer diameter C of the spring 15', but to do this without making the inner diameter smaller (and thus making it overly tight on the tube 11 ), it is necessary to use a wire of smaller diameter. To provide the same spring force this means that the wire must have fewer active coils, but to fit with the other components of the valve fittings the spring 15' must be of the same length. Thus, the alternative form of main spring 15' has fewer active coils in the middle portion, in this case two, and inactive closely spaced coils at either end to make the spring of the correct length. Although the poppet valves of the valve fittings described above operate by a valve member sealing against a lower part of the main seal member, embodiments of the invention may be constructed including a rigid valve seat within the tube and a poppet valve seal member which is moveable.

Referring now to Figures 6 and 7, Figure 6 illustrates a body 2' for use in a third embodiment of a valve fitting according to the invention. The body 2' is identical to the body 2 with the exception that two cut-away portions 40 are provided around the periphery of the opening 3 just above the valve seat 5. Figure 7 illustrates a safety washer 22' for use with the body 2¹ of Figure 6. The washer 22' does not include any cut-away around its circumference as for the washers 22. Other components of the third embodiment of the valve fitting according to the invention will be as previously described with regard to the first or second embodiment.

It will be appreciated that the third embodiment of the valve fitting according to the invention can still be assembled through the opening 3 just above the valve seat 5 because, although no cut-away part is provided on the washer 22', cut-away portions are provided at the narrowest point of the openings 3 in the body 2\ just above the valve seat 5, through which the other components of the valve fitting have to pass during assembly.

Although two cut-away portions 40 are illustrated in Figure 6, valve fittings according to the invention could be designed incorporating a single cut-away portion in the body, and this is acceptable provided that the washer 22' can be passed through the opening 3 just above the valve seat 5 during assembly of the valve fitting.

Although the embodiments of valve fittings according to the invention have been described whereby the body is permanently secured to the keg by welding, it is equally possible for embodiments of valve fittings according to the invention to be removably secured to the keg. Removable well type valve fittings are known, and can be secured by screw thread, circlip or by other means. Clearly, with a removable valve fitting it is not strictly necessary to assemble the valve fitting through the opening in the body, but there may be circumstances in which it is advantageous to do this in any event. When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A valve fitting (1;30) for a keg used for the storage of liquids under pressure, the valve fitting being of the kind known as a well type spear and including a body (2;2') having an opening (3) therethrough with a body valve seat (5) around the opening, a tube (11) with a fluid path (12) therethrough an upper portion of which is located within the centre of the body opening (3) and which is moveable axially relative to the body (2;2') to open and close a first valve, a main seal element (18) secured to the top of the tube (11) and providing a seal surface to co-operate with the body valve seat (5) to seal the first valve, a valve member (17;32) located within the upper portion of the tube (11 ) which is moveable axially relative to the tube (11 ) to open and close a second valve, a valve seat (19;34) within the upper part of the tube (11) with which the valve member (17;32) co-operates to seal the second valve, wherein the valve (1 ;30) is assembled through the opening (3) in the body

characterised in that the valve fitting (1 ;30) further includes a washer (22;22') located on the top of the main seal element (18), the washer (22;22') having a diameter greater than the diameter of the opening (3) in the body (2;2^!), and the washer (22;22') and/or the body (2;2^r) are specifically adapted to permit the washer (22;22') to pass through the opening (3) in the body (2;2^J).

2. A valve fitting (1 ;30) according to claim 1 characterised in that the washer (22) has a portion (24,25) cut-away over a small part of the circumference to enable it to be passed through the valve seat (5) in the body (2;Z).

3. A valve fitting (1;30) according to claim 2 characterised in that the washer (22) has a portion cut from its periphery to provide a secant edge (24).

4. A valve fitting (1 ;30) according to claim 2 characterised in that the washer (22) has a rounded notch (25) cut in its periphery.

5. A valve fitting (1 ;30) according to claim 1 characterised in that the periphery of the opening (3) in the body (2') has a cut-away portion (40) to enable the washer (22') to be passed through the valve seat (5) in the body (2').

6. A valve fitting (1 ;30) according to claim 5 characterised in that the periphery of the opening (3) in the body (2') has two cut-away portions (40).

7. A valve fitting (1 ;30) according to any one of the preceding claims characterised in that the periphery of the washer (22;22') is in contact with the body valve seat (5) when the first valve is closed.

8. A valve fitting (1;30) according to any one of the proceeding claims characterised in that the main seal element (18) has an opening (18c) therethrough to provide a continuation of the fluid path (12) through the tube (11), and wherein the washer (22;22') includes a downwardly extending portion (22a) which fits into the opening (18c) in the main seal element (18) and thereby covers the surface of the main seal element (18).

9. A valve fitting (1;30) according to any one of the preceding claims characterised in that the valve seat (19;34) within the upper part of the tube

(11 ) is provided on a lower surface of the main seal element (18).

10. A valve fitting (1 ;30) according to any one of the preceding claims characterised in that it further includes a main valve spring (15) which biases the first valve closed the main valve spring (15) having a plurality of tightly spaced coils at each end and a plurality of widely spaced coils in a central portion.