BLOW OUT SAFETY

Description of Invention

This invention relates to a vaive fitting for a keg, and particularly to safety features therefor. This invention to a valve fitting for a keg of the kind generally used to store beer, or other liquids, under pressure. The valve fitting may be of any kind but in particular, although not exclusively, may be of the kind referred to within the trade as a 'spear'. The valve fitting to which this invention applies is one which is removable from the keg by the appropriate means such as a screw thread. The valve fitting includes a tube which extends downwardly into the keg and this provides a passage for delivery of fluid into the keg, and for exiting of the fluid from the keg.

Spears are well known as the valve mechanism and extraction tube for dispensing pressurised liquids from containers. There are a number of different types of spears and they have different configurations and shapes and this invention can be applied to any of the different types of spears. However for all the different types of spear in principle the valve mechanism has two valves one has a larger diameter than the other and there is a tube which extends to within a few millimetres from the bottom of the container. The larger diameter vaive opens up into the top of the container whereas the smaller valve opens up and is connected to the tube. The two valves reverse their rolls when filling the container to that of dispensing from the container. In the case of filling, the container it is upside down with the spear at the bottom and the two valves are then opened. The liquid to be stored in the container is forced in through the iarger valve and this pushes any gas in the container via the tube and out through the smaller valve. When dispensing the liquid in the container the container is the right way up with the spear at the top. The two valves are open and gas under pressure comes in through the larger valve and forces the liquid via the tube out through the smaller va!ve. At all stages in its life the container whether it is empty or full it is under pressure. Therefore the pressure in the container can be dangerous to any unqualified person that attempts to remove a spear that does not have any safety features to prevent the spear from blowing out.

According to a first aspect of the invention, we provide a valve fitting for a keg including:- a valve body;

a valve for permitting/preventing flow of fluid through the fluid conduit, a connection formation for engagement with a corresponding formation on a keg for securing the fitting to the keg; and

an abutment member for preventing the valve fitting from becoming completely disconnected from the keg once the connection formation of the fitting has been disengaged from the corresponding formation on the keg.

According to a first aspect of the invention, we provide a vaive fitting for a keg including:- a valve body; and

a valve for permitting/preventing flow of fluid through the fluid conduit, wherein

an externa! surface of the valve body includes first and second threaded sections which are spaced from each other along an axis of the fitting.

According to a first aspect of the invention, we provide a tamper evident member for positioning around a circumference of a formation of a keg which supports a valve fitting, the member being elongate and having means for connecting its free ends to each other, wherein the member includes a projection adapted to extend through an aperture in the neck of the keg. According to a fourth aspect of the invention, we provide a keg including a formation for supporting a valve fitting, the formation having an upstanding circumferential wail which has an aperture for receiving a part of a tamper evident member- Further features of the various aspect of the invention are set out in the dependent claims appended hereto. Accordingly to the present invention, which can be applied to any of the spear configurations and shapes, it provides two independent blow out safety features that prevent any unqualified/unauthorised persons from becoming injured should they attempt to remove the spear from a keg. The invention preferably includes tamper evident means that has to be destroyed/damaged before the spear can be removed to show that someone has tampered with the spear and attempted to remove it.

It should be noted that an authorised person will always make the spear safe from blow out by first releasing the gas pressure from the keg before any attempt is made to remove the spear from the container. However, unauthorised persons often do not know that the keg needs to be depressurised prior to the spear being removed.

The invention will now be explained by way of example using a trilobe spear but it will be appreciated that the invention can be applied to many other types of valve fitting. It should be appreciated, therefore, that the specific embodiment of the invention is described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a side cross-sectional view of an embodiment of a valve fitting according to the present invention its valves open; Figure 2 is a side, part cross-sectional, view of a neck of a keg in accordance with the present invention;

Figure 3a is a side view of a tamper evident member according to the invention;

Figure 3b is a plan view of a tamper evident member according to the invention;

Figure 4 is a side cross-sectional view of a valve fitting according to the present invention fully engaged with a neck of a keg; and Figure 5 is a side cross-sectional view of a valve fitting according to the present invention partially disengaged from a neck of a keg; and

Referring to figure 1 this shows a valve fitting 1 (a 'trilobe' spear) in accordance with the present invention. The seal is item 2 and it is in the open position showing the large valve 7 and the small valve 8 in the open position. These two valves 7 and 8 are opened when filling or dispensing by the appropriate mechanisms (Note neither the filling or dispensing devices are shown in figure 1 ). The spring 4 pushes closed the seal 2 and closes the two valves 7 and 8 when the filling and dispensing mechanisms are removed from the spear 1. There is a washer 3 that prevents the spring from damaging the softer seal 2 material. The body 5 contains all the parts of the spear with the tube assembly 6 being positively fixed to the body 5 and it holds all the spear 1 parts in place. On the outside of the body 5 there are two helical threads 9 and 10. The longer length thread 9 with a thread length W is for holding and sealing the spear in place in conjunction with the formation (or 'neck' as it is commonly known) of the keg 20 (only part shown hi Figure 2). The neck seal 11 ensures that a fluid-tight seal is created {see figure 4). The function of the threaded sections 9, 10 is explained below with reference to Figure 2. The smaller length thread 10 and the undercut with a length Y are features that will be described in detail when referring to figures 4 and 5

Referring to figure 2 this shows the keg neck 12 with an internal thread 13 with a thread length W that is used in conjunction with the longer length thread 9 on the spear 1 for screwing the spear 1 into the neck 12 and forming a seal with the spear 1 neck seal 11 against the sealing face 14 in the keg neck 12. There is an aperture 15 in a circumferentially extending wall of the neck. This aperture 15 together with its position vertically {with respect to the threads 9, 10) and the Internal length X between the bottom of the thread 13 and the seal face 14 are features that will be described in detail when referring to figures 4 and 5

Referring to figures 3a and 3b these show a tamper evident member 16 with sufficient length to go around the circumference of the keg neck 12 where the aperture 15 is located. The member 16 has a cylindrical projection 17 which is configured to extend into and through the aperture 15. One end of the member 16 is tapered to permit easy insertion into the aperture 18a provided in the formation 18 at the opposite end of the member 16. The formation 18 includes holding means for preventing the tapered end of the member 16 from being withdrawn from the aperture 18 once it has been inserted therethrough. In other words, the holding means only permit movement through the aperture 18 in one direction. This means that the tamper evident member 16 needs to be cut in order to remove it.

Referring to figure 4 this shows the spear 1 screwed into the neck 12 which is the position for the spear 1 when it is in use. The member 16 is shown extending around the neck and with the projection 17 in position extending through the aperture 15. The projection 17 protrudes into the neck space X and it is of sufficient length so the projection 17 almost touches the body 5 diameter V of the spear 1. In this position the projection 17 is positioned in the spaced defined between the threaded sections 9, 10. The aperture 15 is positioned vertically as close as possible to the bottom of the thread 13 in the keg neck 12.

If an unauthorised person (e.g. a thief attempting to steal the fluid in the keg or to dilute the liquid in the keg fill with water) attempts to unscrew the spear 1 from the keg neck 12 the first thing that wil! happen after the spear has been unscrewed by about 30% to 40% is that the smaller length thread 10 will be prevented from moving upwards by the projection 17. The unauthorised person can continue unscrewing the spear 1 until it jams solid with the projection 17. At this point the spear 1 cannot be removed and it will not blow out (i.e. be pushed out by the pressure of the fluid in the container). However the unauthorised person could remove the member 16, by cutting it, and then the projection 17 can be pulled out of the aperture 15 in the keg neck 12. Removal of the member 16, however, shows that someone has tampered with the spear 1 and that there has been an attempt to remove, or actual removal of, the spear 1, In addition when the projection 17 has been removed pressurised gas will start to escape from the keg via the aperture 15. An addition feature is that the member 16 could be made in a number of colours and the colouring could be used for date-coding or showing when a specific event has occurred to the spear. Referring to figure 5 this shows the spear 1 and keg neck 12 in the position after the member 16 and the projection 17 have been removed and when ail of the longer length thread 9 of the spear 1 has been unscrewed out of the thread 13 in the neck. The spear 1 has no thread engagement at this point as the length Y the distance between the two threads on the body 5 is longer than W the length of the thread 13 in the keg neck 12. Again if this were an unauthorised person the abutment member in the form of the small length i thread 10 now prevents the spear 1 from coming out of the keg neck 12 as the small length thread 10 is held in the keg neck 12 by a lower most part of the thread 13. Also the small length thread 10 will not easily engage with the thread 13 in the keg neck 12, which prevents simply removal by the unauthorised person. In the position shown in figure 5 there is a large leakage path for pressurised gases from the keg chamber to escape through the aperture 15 in the keg neck 12. The arrows Z shows the escaping pressurised gas. The escaping pressurised gas Z renders the spear 1 safe from being blown out and injuring the unauthorised person. This second safety feature is the combination of permitting the escaping pressurised gas Z from the keg through the aperture 15 while at the same time the smaller thread 10 abuts the thread 13.

Features of the invention as described above, with reference to the accompanying figures, are set out in the following clauses.

1. A spear and keg neck with tamper evident and two blow out safety features. The first blow out safety device occurs when the spear 1 is partly unscrewed out of the neck 12 and the smaller length thread 10 on the spear 1 body 5 prevents the spear 1 from coming out because the smaller length thread 10 comes up against the projection 17 on the member 16 which is held in the neck 12 aperture 15. The second blow out safety feature is when the member 16 is cut and the projection 17 is removed from the aperture 15 in the keg neck 12. So now the spear 1 is unscrewed out of the neck 12 but then the smaller length thread 10 on the spear 1 body 5 prevents the spear 1 from coming out when it comes in contact with the keg neck 12 thread 13. Also without the projection 17 in place in the keg neck 12 the pressurised gas in the keg can escape through the keg neck 12 aperture 15. This renders the spear 1 safe from blow out and the cutting and removal of the member 16 acts as a tamper evident device. 2. A spear and keg neck with tamper evident and two blow out safety features in clause 1 characterised in that there is a thread 13 at the top of the neck 12 with sufficient length of thread W to hold the spear in place as well as creating a screw force that is able to compress a neck seal 11 to prevent any gases escaping from the keg.

3. A spear and keg neck with tamper evident and two blow out safety features in clauses 1 and 2 characterised in that there are two screw threads on the spear 1 body 5 one a longer length thread 9 with a length W and the other a smaller length thread 10. The longer length thread 9 works in conjunction with the screw thread 13 in the keg neck 12 and the longer length thread 9 has the mating thread form and thread length as the keg neck 12 thread 13. 4. A spear and keg neck with tamper evident and two blow out safety features in clauses 1, 2 and 3 characterised in that the smaller length thread 10 is positioned as close as possible to the keg neck 12 sealing face 14 and it has the same mating thread form as the keg neck 12 thread 13 but the length of the thread is as short as possible while ensuring the spear 1 cannot blow out in the event of the longer length thread 9 being totally disengaged from the keg neck 12 thread 13.

5, A spear and keg neck with tamper evident and two blow out safety features in clauses 1 , 2, 3 and 4 in that there is a cut away with a length Y in the spear 1 body 5 that is between the longer length thread 9 and smaller length thread 10 with a diameter V which is less than the route diameter of both the longer length thread 9 and the smaller length thread 10 and the length Y is longer than W the keg neck 12 thread 13. 6. A spear and keg neck with tamper evident and two blow out safety devices in clauses 1 to 5 characterised in that there is a cut away with a length X in the keg neck 12 with a diameter greater than the route diameter of the keg neck 12 thread 13 and the length X equal to the cut away length Y plus the smaller length thread 10 in the spear 1 body 5. 7. A spear and keg neck with tamper evident and two blow out safety devices according to any preceding clause characterised in that there is one a horizontal aperture 15 in the keg neck 12 that is positioned as close as possible to the keg neck 12 thread 13 without impinging into the keg neck 12 thread 13.

8. A spear and keg neck with tamper evident and two blow out safety devices according to any preceding clause characterised in that there is a member 16 as commonly used in tylng electrical cables together that has sufficient length to operate around the diameter of the keg neck 12 where the aperture 15 is.

9. A spear and keg neck with tamper evident and two blow out safety devices according to any preceding clause characterised in that there is a projection 17 on the member 16 that fits into the keg neck 12 aperture 15. The projection 17 has sufficient length so it almost touches the spear 1 cut away diameter V.

10. A spear and keg neck with tamper evident and two blow out safety devices according to any preceding clause characterised in that the member 16 can be any colour but the colour can be used as a specific code for dating or identifying a particular spear 1 maintenance event.

11. A spear and keg neck with tamper evident and two blow out safety devices according to any preceding clause characterised in that the above can be used on all types and configurations of spears in the drinks and chemical industry where the spear is held in with a screw thread. 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.