CONNECTOR FOR PRESSURISED GAS

Abstract: Home carbonation apparatus and a carbon dioxide supply vessel (2) are provided with inter-engageable connector parts (10,16). The part on the apparatus includes a hollow cylindrical male member (14) which has an external seal (18) and within which an axially movable valve actuating plunger (30) is positioned. The part on the vessel includes a female member (12) having a cylindrical internal surface (22) for sealing engagement with the seal (10). The bottom surface (26) of the female member (12) acts as a positive stop so that when the parts are connected and locked together the position of the plunger (30) is precisely defined in relation to the position of an axially movable valve actuating rod (6) provided in the vessel (2).

Description: This invention relates to connectors for pressurised gas and is particularly concerned with such connectors for connecting a vessel containing pressurised carbon dioxide to an apparatus for carbonating water, such as a home carbonation apparatus. Conventional connectors of this type comprise a first part which is integral with a valve housing provided on the carbon dioxide supply vessel and which includes an axially displaceable valve operating member and a second part which comprises a portion of the carbonation apparatus and includes a gas conduit for receiving gas from the vessel, a sealing member forming a gas seal between the two parts and a plunger which may be actuated to effect movement of the valve operating member. The two parts are conventionally screw-threaded together. Known connectors suffer from the problem that proper operation of the valve is not assured. Further, the sealing surface of the vessel may be damaged in use, for example, by dropping, and as a result a proper seal is not achieved. The invention aims to overcome these disadvantages. In one aspect, the invention provides a two-part connector provided with positive stop means acting in the direction of relative movement of the two connectors when they are being joined together so as precisely to define the relative dispositions of the two parts when locked together. It has been found that with this feature, particularly when in accordance with the preferred embodiment of the invention, proper operation of the valve may be assured. In another aspect, the invention provides a two-part connector with a gas seal, wherein at least one of said parts has an internal sealing surface. The invention also resides in the individual parts of the two-part connectors independently of each other. The invention is described further by way of example with reference to the accompanying drawings in which: Figure 1 diagrammatically represents a carbonation apparatus in which the invention is embodied; Figure 2 shows a two-part connector according to a preferred embodiment of the invention, partly in section, with the parts connected together; Figure 3 shows the connector of Figure 2 with the two parts connected together but not locked; Figure 4 shows the parts separated; Figure 5 shows a part of the preferred embodiment of the invention in further section, to show more detail; Figure 6 is a detail of part of the preferred embodiment; and Figure 7 is a detail similar to Figure 6 but with the parts in a different position. With reference to Figure 1, the carbonation apparatus, for home use, is adapted for carbonating relatively small quantities of water such as sufficient to form one or two drinks, and comprises a carbonation chamber 100 to which is connected a water supply means 102 for supplying water to be carbonated, and which has a discharge valve arrangement 104 for discharging carbonated water into a vessel such as a glass 106. A carbon dioxide supply means 108 is connected to the chamber 100 by a conduit 110 for supplying carbon dioxide thereto. A concentrate supply arrangement 112 is connected to the discharge arrangement 104 by one or more conduits 114 for supplying flavouring to the carbonated water. The chamber 100 contains a carbonating device which may be of conventional form e.g. a nozzle for injecting carbon dioxide into the water, or is preferably as described in our published British Patent Application No. 2,161,089. The water supply arrangement and concentrate supply arrangement may also be as described in that published British patent application. With reference to Figures 2 to 5, the carbon dioxide supply arrangement 108 includes a pressurised carbon dioxide bottle 2 provided at its top with a valve housing 4 containing a valve 5 (Fig. 5 only) which is normally closed by a compression spring 7 (Fig. 5 only) but which can be opened by depressing an axially movable valve operating rod 6 which extends through a passage 8 in a connector part 10 which is secured to the valve housing 4 by threads 11 (Fig. 5 only). The connector part 10 includes a cylindrical female element 12 which receives a cooperating male element 14 of a second connector part 16 which is a permanent part of the home carbonation apparatus. The male element 14 carries an external O-ring 18 in a groove 20, the O-ring forming a gas seal with the internal cylindrical surface 22 of the female element 12. When the connector parts 10 and 16 are fully locked together, an end surface 24 of the male element 14 abuts the bottom surface 26 of the female element 12. Surfaces 24 and 26 thus form a positive stop. The second connector part 16 includes a gas passage 28 which contains a plunger 30. Inter-engaging shoulders 32 and 34 are provided on the plunger 30 and in the gas passage 28 respectively to define the retracted position of the plunger 30 as shown in Figure 2. Passage 28 communicates with conduit 110 as shown diagrammatically in Figure 2. A number of locking fingers 36 (for example three fingers) of resilient material, preferably synthetic plastics, are carried by the second connector part 16 by means of a ring 38 with which the fingers are integral and which is mounted in a groove 40 in the connector part 16. The ring 38 may be split so that it may be easily assembled with the connector part 16. The fingers 36 are formed so that in their unstressed condition they assume the position shown in Figures 3 and 4. Each finger is provided at its lower end with an inwardly directed projection 42 which, when the two parts 10 and 16 are locked together as shown in Figure 2, engages an inclined surface 44 provided at the lower side of a locking rim 46 of the valve housing 4. An axially slidable collet 48 is provided on the second connector part 16 for holding the fingers 36 in the position shown in Figure 2 in which the two parts are locked together. The inclined surface 44 is such as to draw the connector parts together as the fingers 36 are moved inwardly. When the two parts are in the locked position shown in Figure 2, and the plunger 30 is not actuated, an end protrusion 50 of the plunger 30 which is adapted to engage the valve operating rod 6 is precisely positioned a predetermined distance above the surface 26, by virtue of the engagement between the shoulders 32 and 34 and between the surfaces 24 and 26, and is therefore precisely positioned in relation to the upper end of the valve rod 6. When gas is to be discharged from the bottle 2, the plunger 30 is actuated so as to move downwardly as shown in Figure 2 into engagement with the rod 6 so as to press the rod 6 downwardly also. This is achieved by means diagrammatically shown in Figure 3 comprising a solenoid 41 connected to one end of a lever 43 whose other end 47 is connected to the plunger 30, the lever being pivoted at a point 45 between its ends. Thus, energisation of the solenoid 41 opens the valve and permits carbon dioxide gas to travel upwardly through the passage 8 and the passage 28, to be used for carbonating water. Further, since the O-ring 18 seals against the internal surface of the female element 12, there is no risk of damage to that internal surface so that a good seal may be always assured. With reference to Figure 6, when the connector is in the condition shown in Figure 2 i.e. the plunger 30 is not actuated, the surface 50 is preferably positioned about 2mm above the surface 26 and the valve rod 6 is arranged so that when the valve is closed the top surface 6a of the valve rod 6 projects about 1mm above the surface 26 so that there is a spacing of about 1mm between the surface 6a and the surface 50. Preferably the stroke of the actuator 30, when the aforesaid solenoid is actuated, is sufficient to force the rod 6 downwardly into a recess 26a in the surface 26. This stroke may, for example, be about 3mm. The distance between the surface 50 and a shoulder 30a on the actuator 30 may be about 1.5 mm so that the shoulder 30a does not quite contact the surface 26 when the valve is fully opened. These dimensions have been found to be particularly advantageous but of course it is possible to depart from them within the scope of the invention. However, where the actuator 30 is arranged with dimensions as described, the top surface 6a of the rod 6 should not project more than 2mm above the surface 26 when the valve is fully closed. It may be approximately flush with the surface 26 when the valve is fully closed or may even be slightly below the surface 26 when the valve is fully closed. Thus, the precise positioning of the actuator 30 in relation to the surface 26 achieved by the invention assures reliable actuation of the valve 5 at all times. If the bottle is to be disconnected, the collet 48 is slid upwardly from the position shown in Figure 2 to that shown in Figure 3. This permits the fingers 36 to move outwardly under their own resilience to the position shown in Figure 3 and thereafter the connector part 10 may be separated from the connector part 16 by drawing the bottle downwardly as shown in Figure 4. Thus, when the carbon dioxide in the bottle 2 has been used up, a fresh bottle may be easily installed. Various modificiations are possible within the scope of the invention. For example, the O-ring 8 could be mounted in an internal groove in the element 12 instead of being mounted on the exterior of the male element 14. A good seal would still be assured because, the element 14 being part of the apparatus for carbonation, there is little risk of damage to it: it is the bottle itself, and parts attached to it, which are most susceptible to damage due to the bottle being inadvertently dropped, for example. Although the use of resilient fingers such as illustrated at 36 in the drawings is a convenient locking means, other locking means may be employed. Further, forms of positive stop other than the surfaces 24,26 and the shoulders 32,34 may be employed for precisely positioning the end of the plunger in relation to the valve actuating rod although the arrangement shown in the drawings is particularly advantageous. Although it is particularly advantageous to use the surfaces 24 and 26 as a positive stop limiting the mnovement of the male connector part 14 into the female connector part 12, other positive stop means could be provided. For example, an inward projection such as a circumferential rib could be provided inside the cylindrical surface 22 near to the bottom to serve the purpose of a stop by cooperation with the end surface 24 of the element 14. As a further alternative, the upper end surface of the female element 12 could cooperate with a stop surface provided on or adjacent the male element 14.

Claims: 1. The combination of carbonation apparatus and a carbon dioxide supply vessel detachably mounted therein, the apparatus having a carbonation chamber, a conduit for supplying carbon dioxide to said chamber, a male connector communicating with said conduit for connecting the conduit to the vessel, the male connector including a hollow cylindrical member, and a valve actuator movably positioned inside the male connector; the vessel having a normally closed valve, a female connector for receiving the male connector and having an internal cylindrical surface, and an axially movable valve operating member arranged to be moved by said valve actuator; said combination further including positive stop means limiting axial movement of the male connector into the female connector, seal means providing a gas seal between said male and female connectors, locking means for locking said connectors together, and means for moving said valve actuator for selectively opening and closing said valve when said connectors are locked together. 2. Apparatus according to claim 1, wherein said positive stop is provided by end surfaces of each of said male and female members. 3. Apparatus according to claim 1, wherein said positive stop is provided by a radial projection or rib inside said female connector. 4. Apparatus according to claim 1 or 2, wherein said locking means comprises a plurality of locking elements movable generally radially for effecting locking between two said parts. 5. Apparatus according to claim 4, wherein each of said elements has and/or engages an inclined surface effective to draw said connector parts to the fully engaged position during locking. 6. Apparatus according to any preceding claim, wherein said actuator is a plunger have a retracted position defined by further stop means. 7. Carbonation apparatus comprising a carbonation chamber, a conduit for supplying carbon dioxide to said chamber; a male connector communicating with said conduit for connecting the conduit to a carbon dioxide supply vessel, said connector including a hollow cylindrical member having a sealing member on its outside; an axially movable plunger positioned inside the male connector for operating a valve operating member of a vessel when connected thereto; and locking means for locking a vessel to said connector. 8. A carbon dioxide supply vessel for use with apparatus according to claim 7, having a normally closed valve and a female connector adapted to receive the male connector by axial sliding movement, said female connector having an internal cylindrical surface adapted to be sealingly engaged by said sealing member and a positive stop for limiting axial movement of said male connector into said female connector, said bottle further including an axially movable valve operating member positioned adjacent the bottom of said female connector to be acted on by said plunger. 9. A vessel according to claim 8, wherein said stop is constituted by an end surface of said female connector. 10. A vessel according to claim 8 or 9, having, below said female connector, a circumferential rib engageable by said locking means for locking the male and female connectors together. 11. A vessel according to claim 10, wherein said circumferential rib has an inclined surface engageable by said locking means, the inclination being such as to draw the male and female connectors into their fully engaged position upon operation of the locking means.

Inventors: CLARK, PETER FEDERICK, SCOTT, ALISTAIR
Applicants: ISOWORTH LIMITED
Application year: 1987
Main classification: F16L37
IPC codes: F16L37, B67D1, B01F1