GB2089954A

GB2089954A - Valve means for dispensing gas

Info

Publication number: GB2089954A
Application number: GB8111196A
Authority: GB
Original assignee: ESSER C DRUCKGASARMATUR
Current assignee: ESSER C DRUCKGASARMATUR
Priority date: 1980-12-23
Filing date: 1981-04-09
Publication date: 1982-06-30
Also published as: DE3048732A1; EP0054717A1; GB2089954B; DE3176132D1; ATE26757T1; EP0054717B1

Abstract

Valve means for the withdrawal of gas, at a low pressure suitable for a domestic appliance from a high- pressure vessel (11) includes a main closure valve (13) for connection to the vessel (11). The valve (13) has a displaceable closure element (22) which is actuated by a tappet (81) which is connected to the spring- loaded diaphragm (76) of an attached reducing valve (14). When the pressure of gas at the outlet side falls, the diaphragm (76) deforms, thus moving the tappet (81) to cause displacement of the closure element (22) to open the main valve (13). The reducing valve (14) may be installed at the lower end (92) of a receiving chute (91), in which a gas cylinder (11) with the main valve (13) attached is slidable downwards, to cause engagement of the main (13) and reducing (14) valves by means of a simple push-in connection. <IMAGE>

Description

1

SPECIFICATION Valve means for dispensing gas

The invention relates to a valve means for the withdrawal of gas at a low pressure (which may be suited to a domestic appliance) for a highpressure vessel.

A valve assembly has been proposed (in German Auslegeschrift 2,830,147), in which a main valve is connected to a high-pressure vessel and has a closure element which is openable by a tappet of a reducing valve by means of a control rod which is pressed down by an eccentric lever to be actuated from outside. During operation, the main closure valve of the high-pressure vessel is constantly open, and the withdrawal of gas is monitored by a secondary closure valve which is located in the reducing valve and the opening and closing movements of which are controlled by the low-pressure diaphragm of the reducing valve.

There is a back-flow preventer consisting of a spring-loaded diaphragm valve which is located in the high-pressure portion of the reducing valve and which closes that gas-inflow orifice of the reducing valve which faces the high-pressure vessel, when the pressure in the high-pressure vessel falls below the low pressure.

The construction of the known valve arrangement is complicated and necessitates a fixed connection, appropriate to the internal pressure of the high-pressure vessel, between the main valve and the reducing valve. Moreover, it is necessary to open the main valve by hand whenever gas is to be tapped, and to close it again by hand if it is intended to remove the reducing valve from the high-pressure vessel. Since the main valve on the high-pressure vessel is constantly open during operation, there is a risk of gas losses, if the secondary closure valve (which is controlled only by the low pressure) does not close in a completely leak-tight manner.

According to the invention there is provided a valve means for the withdrawal of gas at a relatively low pressure from a high-pressure reservoir, said valve means comprising: a main closure valve for connection to the reservoir, said 110 main valve having a closure element displaceable to close or open said main valve; a reducing valve unit connectable with said main valve, said reducing valve unit including a diaphragm arranged so that its configuration is variable in response to the pressure of said gas in said unit; and displacement means constructed and arranged to actuate displacement of said closure element in response to said variation of the configuration of said diaphragm when said main valve and reducing valve unit are mutually connected, whereby said main valve is openable when the pressure of said low pressure gas falls below a desired value.

Preferred embodiments of the invention can substantially avoid the disadvantages of the prior art, and provide a valve means which has a very simple construction, works without danger and can be handled easily by the user.

GB 2 089 954 A -1 Preferred embodiments have the advantage that, when combined with the reducing valve, the main valve is automatically opened by the tappet of said reducing valve and remains open until the desired low pressure is reached in the reducing valve and its low pressure outlet line. The main valve of the high-pressure vessel then closes again automatically, to be opened again thereafter when the set low pressure in the reducing valve falls as a result of consumption on the low-pressure side.

In preferred valve means according to the invention, the diaphragm, stressed by the low pressure in the reducing valve, controls the closure elements of the main valve directly. Therefore, no secondary closure valve is necessary, and the reducing valve can have a very simple and compact construction, since it has itself only the control portion, and no closure valve portion. Since the diaphragm tappet of the reducing valve may act directly on the closure element, of the main valve (or via a valve stem connected to that element), it is not necessary to provide a control linkage such as is required in known valves to transmit the movements of the low-pressure diaphragm to the withdrawal valve.

Since the main valve is normally closed and is opened only when gas is drawn by a consumer, for example a domestic appliance, the high-pressure vessel is always shut off even when the reducing valve is attached and consumer appliances are connected. Consequently, the appliances, connecting lines and reducing valve are always subject only to the reduced pressure.

Since the reducing valve is not subject to high pressure, a simple pushin connection may suffice to connect the reducing valve. The handling of the valve arrangement is, therefore, very simple and reliable. When bottles (gas reservoirs) are changed, it is not necessary to open or close the main valve in a separate step, e.g. by means of an eccentric lever or a handwheel, since the main valve is opened and closed automatically.

In a particularly convenient construction, the tappet passes through the low-pressure diaphragm (and a diaphragm disc, if present) and is screwed into a spring-plate cover or boss which is urged by the diaphragm spring, said tappet clamping the diaphragm, by means of a shoulder, between itself and the diaphragm disc and/or the cover, so as to make a seal. Such a design is especially simple and favours perfect functioning both during connection of the valves and during use.

An especially handy construction is obtained if the reducing valve, a back-flow preventer and a low-pressure safety valve, are assembled in a common housing to form a reducing-valve unit. No connecting lines with joints in which leaks can occur are then required between the individual valves, since the lines leading to the valves can be simple bores in the housing.

In a valve means embodying the invention, a back-flow preventer can be located in the connecting branch of the low-pressure withdrawal line. It is easily accessible there and, also, 2 - GB 2 089 954 A '2 undergoes only a small amount of wear, since it is subject only to low pressure.

The reducing valve unit can be screwed on to the main valve. However, especially convenient is a push-in connection between the main valve and the reducing-valve unit, permitting simple handling especially for technically unskilled per sons such as housewives and children.

In an especially convenient embodiment, the reducing-valve unit is fixedly installed at one end of the receiving means for the high-pressure vessel, e.g. a suitable cavity, said receiving means having at the opposite end a support which abuts the high-pressure vessel, so as to hold its main valve in proper connection with the reducing valve. In this case, the reducing-valve unit is advantageously built into a receiving means for the high-pressure vessel, in such a way that the tappet of the reducing valve points upwards and presses from below against the closure element of 85 the main valve of the high-pressure vessel when this is inserted upside down in the receiving device.

A valve arrangement of this type is especially suitable forthe supply of a gas in a household, since it is especially simple to exchange an empty gas bottle for a full one. For example, the valve arrangement according to the invention can be applied to advantage for supplying carbon dioxide to appliances which dispense drinks containing carbon dioxide. Here, it is merely necessary to allow the gas bottle to slide into the receiving means with the main valve, serving as filling and shut-off valve, foremost, the main valve pushing itself, under the weight of the bottle, into engagement with the reducing valve. By means of the support, which can be, for example, a flap closing the receiving cavity or a sloping surface delimiting the top thereof, a sufficiently high force can then be exerted on the upward-pointing bottom of the bottle, said force being sufficient to open the main valve when the tappet of the reducing valve presses on the closure element and the main valve slides completely into the receiving location provided for it in the reducing valve. 110 Further features and advantages of the invention emerge from the following description and the drawings, in which a preferred embodiment of the invention is described in more detail: 115 Figure 1 shows, in longitudinal section, a valve means according to the invention placed on a high-pressure vessel, Figure 2 is a view similar to Figure 1, but showing the reducing valve separated from the 120 main valve, and Figure 3 shows a partial view, in a vertical section, of a kitchen cupboard or bar cabinet with a receiving device for a high-pressure gas bottle, with the reducing valve of the valve means built in. 125 In the drawings, 10 designates a valve means or arrangement for a high-pressure vessel 11 which is designed as a gas bottle and which contains CO, gas under high pressure.

The valve arrangement 10 comprises a main valve 13, which is screwed into the bottle neck 12 of the high pressure vessel 11, and a reducing valve 14 pushed on to this main valve.

The main valve 13 serves as a filling and shut- off valve for the gas bottle 11 and acts, together with the reducing valve 14, as a withdrawal valve, by means of which C02 gas, at a low pressure adjusted to a consumer appliance not shown in more detail, can be withdrawn from the highpressure vessel 11, as wi!i be explained in more detail below.

The main valve 13 consists of an essentially cylindrical valve body 15 which is screwed in a sealing manner by means of a conical external thread 16 into the neck 12 of the gas bottle 11. The valve body 15 has an axial valve bore 17 which widens outwards in several stages or steps 1 7a, 1 7b, 1 7c and 1 7d from that end face 18 of the valve body 15 which reaches into the interior of the high pressure vessel 11. Located on the shoulder 19 between the first step 17a and the second step 1 7b is a sieve 20. on the outer margin of which is supported a valve spring 21, which bears with its other, outer end on the inner end face of a valve-closure piece 22 located in the section 1 7b of the valve bore 17.

The valve-closure piece 22 is an essentially cylindrical body which is movable to and fro in an axial direction in the valve bore 17 with peripheral play and which has a blind hole 23 which emerges from the outer end face of said valveclosure piece and is provided with an internal thread, and into which a valve stem 24 is screwed. The valve stem 24 is surrounded on the outer end face 25 of the closure piece 22 by a sealing ring 26 lying in an annular widening of the blind hole 23, said widening starting from the outer end face of the closure piece 22 and ending flush with the sealing ring 26.

The valve stem 24 passes through a valve-seat screw 27 in which it can slide in an axial direction and which is screwed into an internal thread of the step 17c of the valve bore 17. The valve-seat screw 27 is stepped in its outside diameter and is sealed off from the valve bore 17 by means of an 0-ring 28. This valve-seat screw engages over the shoulder between the steps 1 7c and 1 7d of the valve bore 17 by means of a continuous flange 29 and forms with its inner margin, facing the closure piece 22, an annular valve-seating face 30 which surrounds the valve stem 24 and which lies opposite the sealing ring 26 let into the valve closure piece 22. With its upper end 31 the valve seat screw 27 projects into the step 1 7b of the valve bore 17 with the largest diameter and terminates a little below the outer end face 32 of the valve body 15, whereas, when the valve closure piece 22 lies against the valve seat 30, the valve stem 24 projects a little above the outer end face 33 of the valve-seat screw 27.

Next to the axial valve bore 17 is an eccentrically arranged axial bore 34 which leads to a high-pressure safety device designated as a whole by 35.

The high-pressure safety device 35 is screwed z 3 into a laterally moulded-on projection 36 of the valve body 15 and consists essentially of a bursting disc 37 clamped between a copper ring 38 and a sliding ring 39. A cup-shaped securing screw 40, the bottom 41 of which has an orifice 42 and is covered with an inspection disc 44, presses on the sliding ring 39. The inspection disc 44 is clamped into a turned-up rim 45 on the securing screw 40. When the maximum permissible pressure is exceeded on the inside of the high-pressure vessel 11, the bursting disc 37 is destroyed, so that the inspection disc 44 jumps out. It is then possible to recognise from outside that the maximum permissible pressure on the inside of the bottle has been exceeded.

The reducing valve 14 can be seen best in Figure 2. It forms, together with a low-pressure safety valve 46 and a back-flow safety valve 47, a structural unit which is designated below as a "reducing-valve unit" and which will, as a whole, be given the reference numeral 50.

The reducing valve 14, the low-pressure safety valve 46 and the back-flow safety valve 47 have a common valve housing 48 which consists of a cylindrical outer part 48a of a relatively large diameter and of a cylindrical inner part 48b of a relatively small diameter, these parts being on opposite axial sides of a radially inwardly extending wall portion 49.

Located on diametrically opposite sides of the 95 inner housing part 48b are the connecting nozzle 51 for the low-pressure withdrawal line 52 and an appropriately designed housing nozzle 53 receiving the low-pressure safety valve 54 which will be described in more detail below. The wall portion 49 has a central orifice 55 surrounded by an annular flange 56 located at a distance from the inner peripheral wall 57 of the inner housing part 48b, said distance being adapted to the thickness of the wall 58 of the valve body 15 of the main valve 13 in the region of the outermost step 1 7d of the valve bore 17.

It will be seen from Figure 1 that, when the reducing-valve unit 50 is placed on the main valve 13, the annular wall 58 of the valve body 15, on the one hand, and the upper part 31 of the valveseat screw 27, on the other hand engage into (a) the annular space 59 (Figure 2) between the outer wall of the inner housing part 48b and the annular flange 56 and, (b) into the central orifice 55 enclosed by this annular flange 56, respectively. The valve-seat screw 27 is sealedly engaged within the annular flange 56 of the reducing-valve housing 48 by means of an O-ring 60, when the reducing-valve unit 50 is pushed on to the main valve 13.

The low-pressure safety valve 46 and the backflow safety valve 47 have the same design, so that only one of these two valves will be described below. The only difference is the force of the valve 125 spring, which is very much greater in the lowpressure safety valve 46 than in the back- flow safety valve 47, since this last-mentioned valve serves only to prevent a back-flow out of the connecting line 52 into the interior of the valve GB 2 089 954.A 3 arrangement 10 and, if appropriate, also into the interior of the high- pressure vessel 11, when the pressure in the high-pressure vessel 11 and in the valve arrangement 10 falls below the set low pressure.

It will be seen from Figure 2 that an annular seating face 61 is formed at the base of the connecting nozzle 51, said seating face surrounding a radial bore 62 opening into an axial bore 63 which extends through the wall portion 49 outwards into the low- pressure space 64 enclosed by the housing 48. Located in the radially extending cylindrical inner space 65 of the connecting nozzle 51 is a cup- shaped valve- closure piece 67, in the bottom 68 of which is embedded a sealing washer which rests on the valve-seat face 61. The valve-closure piece 67 can be displaced axially in the interior 65 of the connecting nozzle 51 and is loaded by a valve spring 69 which is supported with its one end against the valve-closure piece 67 and with its other end against a closure cap 70 which is screwed into the outer end of the connecting nozzle 51 and has a gas-outlet orifice 71 through which the gas which is under low pressure can enter the withdrawal line 52.

As already mentioned, the low-pressure safety valve 46 is designed in exactly the same way. A radial bore 62' connected via an axial bore 63' to the low-pressure space 64 leads into the valve space 65.

The reducing valve 14 will now be described in more detail below. It should first be pointed out, in this context, that only the regulating portion of this reducing valve is present in the reducing-valve unit 50, whilst the association valve portion is formed by the main valve 13, when the reducingvalve unit 50 is pushed on to the main %alve 13.

The reducing valve 14 has a cap 72, open on one side, which is screwed by means of an external thread 73 into the cylindrical wall of the outer housing part 48a. A valve diaphragm 76 made of an elastomer is clamped between the free end margin 74 of the cap 72 and a shoulder 75 of the wall portion 49, said shoulder adjoining the - wall of the outer housing part 48a. Located on - that side of the diaphragm 76 which faces the inner space 77 of the cap 72 is a diaphragm disc 78 on which a spring-plate cover 79 is, in turn, arranged. The spring-plate cover 79 has an approximately frustum-shaped design and has a threaded bore which is open towards the diaphragm 76 and into which the threaded shank 80 of a valve tappet 81 is screwed, said valve tappet bearing with a shoulder 82 on the underside of the diaphragm 76 and passing through the latter and the diaphragm disc 78 and, as a result, clamping the diaphragm 76 in a gas-tight manner between its shoulder 82 and the diaphragm disc 78.

Supported on the outer margin of the springplate cover 79 is one end of a compression spring 84, the other end of which bears on the outer rim of a cup-shaped spring plate 85. The cup bottom 86 of the spring plate 85, in turn, bears on the tip 4 --- GB 2 089 954 A 4 of an adjusting screw 86' which is screwed from outside into a thread of the reducing-valve housing cap 72 and which is closed by a dummy plug 87. The tension of the spring 84 can be varied by means of the adjusting screw 86, and the desired low pressure can thus be set.

The main valve 13 also has a protective cap which is placed on the main valve 13 while the high-pressure vessel is being transported and which engages into the annular groove 88 provided for this purpose, but which is not shown in the drawing.

The mode of operation of the valve arrangement is as follows:

To enable CO, gas, at a low pressure adjusted to a consumer appliance, to be withdrawn from the high-pressure vessel 11, the reducing-valve unit 50 is pushed on to the main valve 13 from above, or is screwed on to it if those parts 58 and 48b of the main valve 13 and the valve housing 48 which engage with one another are provided with a thread. In the last phase of attachment, the tappet 81 presses on to that end of the valve stem 24 which projects out of the valve-seat screw 27 and pushes said valve stem, together with the valve-closure piece 22 fastened thereto, inwards, that is to say, in the direction of the interior of the high-pressure gas bottle 11. As a result, the sealing ring 26 of the valve-closure piece 22 lifts off from its seating face 30, and the C02 gas which is under high pressure flows through the valve bore 17 past the peripheral wall of the valveclosure body 22 and the seating face 30 along the valve stem 24 into the low-pressure space 64 of the reducing valve 14, and thence through the bores 63 and 62 past the valve-closure piece 67 of the back-flow safety valve 47 into the withdrawal line 52. Since, as a result, the pressure in the low-pressure space 64 rises above atmospheric pressure and the set low pressure, the diaphragm 76 and, with it, the tappet 81 are pressed upwards against the action of the diaphragm spring 84, as a result of which the tappet 81 lifts off again from the valve stem 24, and the valve-closure piece 22 is pressed on to its 110 seat again by the valve spring 21 and, consequently, the high-pressure vessel 11 is shut off again.

When the pressure in the low-pressure space 64 then falls again, because gas is withdrawn through the withdrawal line 52 by a consumer, the diaphragm 76 is pressed downwards by the compression spring 84, together with the valve tappet 8 1, so that the valve stem 24 and, with it, the valve-closure piece 22 are pushed downwards, and the main valve is opened until the desired low pressure is restored in the low pressure space 64.

It will be seen from this that the main valve 13 opens only when gas is withdrawn through the withdrawal line 52, but that the main valve 13 always remains closed when the consumer is disconnected.

If the pressure in the high-pressure vessel falls below the low pressure, which is the case when 130 the gas bottle becomes empty, the reducing valve will open the main valve 13 via the tappet 81. In order, in such a case, to prevent a back-flow of gas and, possibly, of liquid mixed therewith into the valve arrangement 10 and the high-pressure vessel, the back-flow safety valve 47 is provided. Here, the closure body 67 is pressed on to its seat by the valve spring 69, as soon as the pressure in the low-pressure space 64 of the valve arrangement 10 falls below the set low pressure.

If a fault occurs in the valve arrangement 10 and, in this case, a prescribed maximum pressure of approximately 5 to 6 bars is exceeded, the lowpressure safety valve responds in such a way that its valve-closure body lifts off from its seat against the action of the spring set to this safety pressure and allows the gas to escape through the bores 63' and 62' and the interior 65' of the low pressure safety valve 46.

Figure 3 shows an especially appropriate arrangement of the valve according to the invention when this is used in a household for attaching to an appliance. The arrangement illustrated here is provided, for example, for use in a bar where carbon dioxide gas supplied in small gas bottles is to be fed to a dispensing device for drinks.

A shaft 91 slightly inclined to the vertical, the lower end 92 of which narrows like a funnel with sloping walls 93, is provided as a receiving device in a table or cabinet 90 for receiving the highpressure vessel 11, namely the gas bottle filled with COV The reducing-valve unit 50 together with the withdrawal line 52 leading to the appliance is located in a fixed position under the relatively narrow funnel orifice 94. On the top side the receiving shaft 91 is closed by the table top 94' of the table, which presses against the high pressu re vessel 11 when this is pushed, with its main valve 13, into the reducing valve 50, which is permanently mounted. Located on the front side 95 of the table is a drop-in orifice 96 for the gas bottle, which orifice can be closed by means of a flap 97 on which is located a lever 98 which can pivot together with said flap and which positions itself laterally next to the bottle 11 when the flap 97 is closed.

When the high-pressure vessel 11 is empty, it is merely necessary to open the flap 97 and take the gas bottle 11 out of the shaft 9 1. This causes the main valve 13 to close automatically, since the valve spring 21 immediately presses the valve closure piece 22 on to its seat 30, when the valve stem 24 is no longer loaded by the tappet 8 1.

A new, filled gas bottle 11 can then be allowed to slide again through the loading orifice 96 into the receiving device 9 1, the main valve 13 sliding along the sloping faces 93 of the funnel and being introduced automatically into the reducing valve.

The initially high resistance when the main valve 13 is being opened is easily overcome, when the flap 97 is closed, due to the fact that the lever 98 connected to the flap 97 pushes the rear end of the bottle so that it slides along the underside of the table top 94, so that the bottle is pushed z down into the shaft 91 until the parts 31 and 58 of the main valve 13, on the one hand, and the parts 48b and 56 of the reducing-valve unit 50, on the other hand, engage completely with one 65 another.

In the arrangement described a special advantage is that, during operation, that is to say, after the main valve has just been opened for the first time and the low pressure set in the valve arrangement has been reached, never to be substantially exceeded even when gas is withdrawn, the pressure exerted by a conventional gas bottle is greater than the low pressure. For this reason, a simple push-in connection between the main valve and reducing-valve unit is sufficient, and it is possible, at any time, to remove the high pressure vessel out of the s6ft and to reintroduce it, without danger. There is no danger of an accident even if the table top 94' becomes loose 80 during operation or is removed from the table 90.

The invention is not restricted to the exemplary embodiments, but a number of changes and additions are possible, without departing from the scope of the invention. As already indicated, a screw connection, a bayonet lock or the conventional ball-retaining ring can also be provided between the main valve and the reducing-valve unit. It is also possible to make the valve arrangement without the safety valves, e.g.

if other safety devices are present. The upside down arrangement of the high-pressure vessel and reducing valve can also be designed somewhat differently, without departing from the idea of the invention.

Claims

1. Valve means for the withdrawal of gas at a relatively low pressure from a high-pressure reservoir, said valve means comprising:

a main closure valve for connection to the reservoir, said main valve having a closure element displaceable to close or open said main valve; a reducing valve unit connectable with said main valve, said reducing valve unit including a diaphragm arranged so that its configuration is variable in response to the pressure of said gas in said unit; and displacement means constructed and arranged to actuate displacement of said closure element in response to said variation of the configuration of said diaphragm when said main valve and reducing valve unit are mutually connected, whereby said main valve is openable when the pressure of said low pressure gas fails below a desired value.

2. Valve means according to claim 1 wherein said configurational variation of said diaphragm is urged by spring means in a sense to cause opening of said main valve, the spring force of said spring means being selected to determine said desired value of the low-pressure.

GB 2 089 954 A 5 Valve means according to claim 1 or claim 2 wherein said displacement means comprises a tappet mounted to said diaphragm.

4. Valve means according to claim 3 when dependent on claim 2, wherein the tappet passes through the diaphragm and is secured to a boss, the diaphragm being sealedly clamped between a shoulder on the tappet and said boss; said spring means acting on said diaphragm via said boss, which is displaceable to allow said variation of the diaphragm.

5. Valve means according to any one of the preceding claims wherein said reducing valve unit includes back-flow prevention means.

6. Valve means according to claim 5 wherein said reducing valve unit includes said back-flow prevention means, a low-pressure safety valve, and said diaphragm in common housing.

7. Valve means according to claim 6 or claim 7 wherein said back-flow prevention means is located at or adjacent the outlet for said lowpressure gas from the valve means.

8. Valve means according to any one of the preceding claims wherein the reducing valve unit and the main valve are threaded for mutual connection.

9. Valve means according to any one of claims 1 to 7 wherein said reducing valve unit and main valve are connectable by means of complementary formations enabling a push-in connection.

10. Valve means according to any one of the preceding claims wherein the reducing valve unit is located in a fixed position at one end of receiving means for a said high-pressure reservoir, said receiving means having at the opposite end an abutment, the receiving means being dimensioned to receive a said high- pressure reservoir with a said main valve mounted thereto with the main valve connected to the reducing valve and the remote end of the reservoir abutting said abutment.

11. Valve means according to claim 3 or any of claims 4 to 10 when dependent thereon, wherein the reducing valve unit is built into a receiving means for the high-pressure reservoir with the tappet extending upwardly from the unit so as to press directly or indirectly from below against the closure element of the main valve when said main valve is mounted to the high-pressure reservoir and this is arranged upside down in the receiving means.

12. Gas dispensing means comprising a valve means according to any one of the preceding claims and a high pressure reservoir to which said main valve is connectable.

13. Means according to claim 12 wherein said reservoir is a gas cylinder. 120

14. Valve means for the withdrawal of gas at a relatively low pressure from a high pressure reservoir substantially as described herein with reference to and as illustrated in Figures 1 and 2 or Figures 1 to 3 of the accompanying drawings.

6 GB 2 089 954 A 6

15. Gas dispensing means substantially as described herein with reference to and as illustrated in Figures 1 and 2 or Figures 1 to 3 of the accompanying drawings.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1982. Published by the Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.

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