IMPROVED LOCKING RING

Abstract: A valve mechanism for application to a liquid container such as a beer keg to enable liquid in the container to be dispensed through a connector by the application of top pressure to the liquid within the container wherein the valve mechanism includes a locking ring by means of which the connector may be secured in position on the valve mechan­ ism and wherein the locking ring has arcuate teeth which are inclined on the underside and arcuate openings between the teeth characterised in that the teeth of the locking ring are specially shaped so that the locking ring can be removed only by using a specially shaped unlocking tool adapted to fit the locking ring and further characterised in that the special shaping of the locking ring includes the provision of inclined surfaces between the teeth and the openings so that the teeth merge into the openings at one end of each tooth, the inclined surfaces being so positioned that any attempt to remove the locking ring by means of an unauthorised tool is frustrated due to the fact that the unauthorised tool simply rises up on the inclined surfaces and does not turn the locking ring.

Description: IMPROVED LOCKING RING This invention broadly relates to apparatus for delivering a liquid from a container to a dispenser. One example of the apparatus which we have in mind is apparatus for delivering beer from keg to a dispensing tap. For many years beer was delivered from the brewery to the public house in wooden casks and what was called a beer engine was used to pump the beer from the cask to a dispenser. Then so called keg bitter was developed and the beer is often now delivered in. metal casks with a closed valve at the top. At the public house a connector is attached to the valve and the connector is then operated so that the valve is opened and the beer can be dispensed. The valve mechanism and the connector are well known and it might be thought that little difficulty would be experienced with such equipment. However one problem that has arisen is that it has been found that a part of the connector can be used as a tool to open the valve on the cask by removing a locking ring. This is dangerous from two points of view: a) the beer inside the keg may be under high pressure and may injure someone who is trying to tamper with the valve. b) If the valve be removed so that a drayman can have an unauthorised drink the beer in the keg may become contaminated. It is therefore an object of the invention to provide an improved form of valve which will not allow the connector to be used as a tool for removing the locking ring of the valve mechanism. Another difficulty is that the connector includes sealing means including a resilient washer that is expanded as the connector is connected to the valve which is normally done by screwing the connector into the valve. This works very well but if the connector be screwed too tightly into the valve it has been found that the mechanism locks solid and it is then very difficult to disconnect the connector from the valve when the keg to which the valve is connected is empty. Another object of the invention is therefore to provide means to prevent the connector being screwed so tightly on to the valve mechanism as to cause the two to be virtually locked together. In known apparatus the locking ring which holds the valve mechanism in position within another casing is substantially smooth at the top and has arcuate teeth, usually a pair, which are inclined on the underside to locate the connector and expand and seal the resilient washer. The locking ring also has two arcuate cut outs or openings between the teeth which may be used when screwing the locking ring into position the two ends of each arcuate cut out or opening being substantially vertical. It is these cut outs or openings which enable the connector to be used as a tool to remove the locking ring in an unauthorised way. According to a feature of the invention we provide a valve mechanism with a special form of locking ring that can be removed only by using a special tool designed to fit and to remove the ring. Our new locking ring has arcuate teeth and arcuate cut outs or openings assbefore but as the teeth merge into the cut outs or openings at one end of each tooth we provide an inclined surface, the inclined surface being so positioned that any attempt to use the connector as a tool to remove the locking ring is frustrated because the connector simply rises up on the incline and does not turn the ring to unscrew it. According to another feature of the invention the locking ring is provided with a stop or stops adapted to engage with a lug normally provided on a lug ring on the connector so that when the connector is being applied to the valve a stop on the locking ring engages with a lug on the lug ring before the connector can be turned too far. In this way it is almost impossible to turn the connector so far that it cannot easily be removed when it is necessary to apply the connector to a new cask. In order that the invention may be more clearly understood reference is now directed to the accompanying drawings given by way of example in which: Fig. i is a longitudinal sectional view of a known form of valve mechanism or down. tube assembly as it is known in the trade. This part of the equipment is fitted to a beer keg at the brewery so that a keg should arrive at a public house with this equipment in position. Fig. 2 is a longitudinal sectional view of a known form of connector usually called a lever type connector in the trade. At the public house the keg is usually placed in the cellar and a cellar man connects the connector to the valve mechanism shown in Fig. i by a downward and turning movement. Fig. 5 includes detail vieafs of a known form of locking ring which is applied to the valve mechanism at the brewery and Fig. 4 includes detail views of the new form of locking ring according to the invention. Referring to the drawings Fig. 1 shows a valve mechanism including a locking ring 1, a centre sleeve seal 2, a rubber valve 3, a spring 4, a centre sleeve 5, a circlip 6, a beer or other liquid valve 7 and a depending spear 8. The operation of this equipment is well known and will not be described in detail. The principle is that when top pressure is applied to the liquid e.g beer in the keg and when the valve 7 is open i.e lowered against the action of the spring, the beer will flow up the spear 8 and through the valve. -The beer flows through the locking ring into the lever type connector shown in Fig 2 and up through a ball valve 21 into a centre tube 7' and so to a beer dispenser in the bar. The connector has a valve housing 19 which terminates at its lower end in two horizontal lugs that are inserted into the locking ring through the arcuate cut-outs or openings which are shown at-23 in Fig 3. After insertion the connector is turned clockwise (viewed from the top) to secure the connector in position. It is this turning movement that can be overdone by an over zealous cellar man. Fig. 4 shows a locking ring 30 with arcuate teeth 33 and arcuate openings 32 between the teeth, the openings merging into the teeth as shown by an inclined or sloping shoulder 31 so positioned that any attempt to unscrew the locking ring 50 by a normal tool is frustrated because the tool simply runs up the incline. Looking at the locking ring from above therefore the inclined or sloping shoulder 31 is at the right hand end of each tooth or at the left hand end of each opening. The shoulder 31 may be a simply inclined straight surf###S we prefer to make the shoulders 31 so that they each form a part of a helix so that the inclined surface merges gently into the top of the adjacent tooth. The feature of the invention therefore comprises an improved form of locking ring and also a valve mechanism including an improved form of locking ring. It will be understood that the locking ring is secured to the valve mechanism at the brewery by using a special tool devised for the purpose and that the locking ring is not thereafter removed until the keg is returned to the brewery whereupon the special tool can be used to remove the locking ring to enable the valve mechanism to be removed for periodical maintainance. (Cleaning and refilling can be carried out with the valve in situ.) In order to prevent the connector being screwed too tightly into the valve mechanism we may provide, according to the second feature of the invention a stop or as illustrated stops 34 below each of the inclined surfaces. The stops, or one of them, engage(s) with the lugs on the lug ring and so prevent over tightening of the connector when applied to the valve mechanism. While we have described the invention mainly in relation to beer kegs - and by beer we include bitter and other forms of ale, lager and stout - it will be understood that the invention may be used with other equipment e.g. apparatus for dispensing other beverage liquids such as cider as well as other liquids when required. To complete the description of the invention it should be understood that a locking ring with two teeth or lugs 33 and two openings 32 has been given purely by way of example. For some purposes it may be useful to use three or even four teeth 33 with a corresponding number of openings between the teeth and by way of example Figure 5 illustrates an embodiment of locking ring with three teeth and three openings. Finally reference has been made above to the use of a special tool shaped to fit the locking ring so that the locking ring can be unlocked only by means of the special tool which can be regarded as a key to unlock the ring by unscrewing it from the rest of the valve mechanism. Figure 6 is a view of the special tool for use with the locking ring illustrated in Figure 4. Although in Figure 4 quite a long thread has been shown it will be realised that a short or long thread, as desired, may be used to connect the ring to the body of the valve mechanism. The operation of the unlocking tool shown in Fig. 6 is as follows. A slideable sleeve 56 and Åa slideÅable drive collar 54 are moved up i.e. to the right in Figure 6 to the position in which they are shown and the tool is then ready for insertion into the locking ring. The main body 57 of the unlocking tool has a rectangular projection or lug 53 which is shaped to fit the openings 32 in the locking ring 30 and the lug 53 is accordingly pressed into one of the openings 32. The unlocking tool is then turned in a clockwise direction until the lug 53 contacts one of the stops 34 on the locking ring 30. The drive collar 54 is then turned in a clockwise direction so as to mesh a helix 60 on collar 54 with one of the helical sloping shoulders 31 on the locking ring 30. The slideable sleeve 56 is then pressed down and turned clockwise which locks the drive collar 54 in its down position i.e. to the left in Figure 6 due to the engagement of a pin 55 on the body in slot 61 in sleeve 56. The unlocking tool is now ready to remove the locking ring 30 and to do that the unlocking tool is turned anti-clockwise by means of a tommy bar 59 so that the sleeve 56 is turned anti-clockwise and is pulled upwards, i.e. to the right in Figure 6, and the drive collar is also pulled upwards. This has the effect of rotating the locking ring 30 clockwise and it is thus released and extracted from the valve.

Claims: CLAIMS: 1. A valve mechanism for application to a liquid container such as a beer keg to enable liquid in the container to be dispensed through a connector by the application of top pressure to the liquid within the container wherein the valve mechanism includes a locking ring by means of which the connector may be secured in position on the valve mechanism and wherein t#he locking ring has arcuate teeth which are inclined on the underside and arcuate openings between the teeth characterised in that the teeth of the locking ring are -specially shaped so that the locking ring can be removed only by using a specially shaped unlocking tool adapted to fit the locking ring and further characterised in that the special shaping of the locking ring includes the provision of inclined surfaces between the teeth and the openings so that the teeth merge into the openings at one end of each tooth, the inclined surfaces being so positioned that any attempt to remove the locking ring by means of an unauthorised tool is frustrated due to the fact that the unauthorised tool simply rises up on the inclined surfaces and does not turn the locking ring. 2. A valve mechanism according to claim 1 characterised in that the locking ring is provided with a stop or stops adapted to engage with a lug on a lug ring on the connector so that when a connector is being applied to the valve mechanism the stop or one of the stops on the locking ring engages with the lug on the lug ring before permitting the connector to be turned too far. 3. A valve mechanism according to claim 2 characterised in that the locking ring has two teeth and two openings. 4. A valve mechanism according to claim 3 characterised in that a stop is provided below each inclined surface. 5. A locking ring for use in a valve mechanism for application to a liquid container to enable liquid to be dispensed through a connector by the application of top pressure to the liquid within the container wherein the locking ring is adapted to secure the connector in position by the provision of arcuate teeth which are inclined on the underside and arcuate openings between the teeth characterised in that the teeth of the locking ring are specially shaped so that the locking ring can be removed only by using a specially shaped unlocking tool adapted to fit the locking ring and further characterised in that the special shaping of the locking ring includes the provision of inclined surfaces between the teeth and the openings so that the teeth merge into the openings at one end of each tooth, the inclined surfaces being so positioned that any attempt to remove the locking rings by means of an unauthorised tool is frustrated due to the fact that the unauthorised tool simply rises up on the inclined surfaces and does not turn the locking ring. 6. A locking ring according to claim 5 characterised in that the locking ring is provided with a stop or stops adapted to engage with a lug on a lug ring on the connector so that when a connector is being applied to the valve mechanism the stop or one of the stops on the locking ring engages with the lug on the lug ring before permitting the connector to be turned too far. 7. A locking ring according to claim 6 characterised in that the locking ring has two teeth and two openings. 8. A locking ring according to claim 7 characterised in that a stop is provided below each inclined surface. 9. A liquid container such as a beer keg provided with a valve mechanism as claimed in any of claims 1 to 4. 10. A valve mechanism substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings in combination with a special unlocking tool as shown.

Inventors: COOK, ROBERT BERNARD
Applicants: UNIVERSAL EQUIPMENT CO (LONDON) LTD
Application year: 1982
Main classification: B67D1
IPC codes: F16L37, B67D1