GB2125518A - Gas inlet device for pressure vessel - Google Patents

Abstract

An inlet device for use with a domestic brewing keg, to enable gas to be introduced from a pressurised cylinder, comprises a tubular body 10 defining an inlet 24 adapted to receive a nose portion of a gas cylinder. An externally threaded insert 28 is mounted in the body to provide an abutment with which the cylinder nose portion can be forcibly engaged to cause release of gas from the cylinder. A screw-driver slot 32 enables removal of the insert for substitution by another of different form. The alternative insert is suitable for use with a cylinder of the kind comprising a breakable seal, the insert comprising a protruding piercing tube. <IMAGE>

Description

SPECIFICATION Inlet device to enable pressurisation of a vessel from a gas container This invention is concerned with an inlet device suitable for use in association with a pressure vessel to enable gas to be introduced as required into the vessel from a pressurised gas container. The invention may find application especially in apparatus for use in domestic brewing and winemaking.

An inlet device is known which is suitable for use in association with a domestic brewing keg to enable gas (e.g. carbon dioxide) to be introduced into the keg from a pressurised gas cylinder. Pressurisation of the keg may be desirable both to prevent beer in the keg from going flat, and also to assist with dispensing the beer from the keg through a tap. The known inlet device comprises a tubular, externally-threaded, body which can be screwed into an internally-threaded connecting portion of a pressurised gas cylinder to cause a nose portion of the cylinder to enter an inlet in the body and be forcibly engaged against a surface of the body at the bottom of the inlet.

Such forcible engagement causes actuation of a valve of the cylinder to release gas from the cylinder. A gas flow passage leads from the inlet, and flow controlling means of the device is adapted to allow gas to pass along the passage to a keg to be pressurised but to prevent depressurisation of the vessel, through the device, when the container is removed from the inlet. The flow controlling means of the known device comprises a safety valve arrangement to allow escape of gas from the keg should overpressurisatiovi of the keg tend to occur.

A disadvantage of the known device is that it is suitable for use only with gas containers comprising a certain form of gas-releasing arrangement viz. one in which the nose portion comprises a valve-operating plunger which is so arranged in relation to the surface at the bottom of the inlet that that surface will depress the plunger to actuate the valve when the device and the cylinder are screwed together. Should it be desired to make use of a cylinder with a different form of valve-operating means, a new inlet device might be required to provide a suitable actuating arrangement at the bottom of the inlet. Furthermore, another well-known form of gas cylinder does not have an operable outlet valve at all, but rather a breakable seal which must be pierced to release the gas from the cylinder, and this requires yet another form of actuating arrangement in the inlet device.

It is an object of the present invention to provide an inlet device which is so constructed and arranged that it can readily be modified to suit it for use with gas containers comprising different forms of gas-releasing arrangements.

The invention provides in one of its aspects an inlet device suitable for use in association with a pressure vessel to enable gas to be introduced as required into the vessel from a pressurised gas container, the device comprising means defining an inlet adapted to receive a nose portion of a gas container, a threadedly mounted removable insert providing an abutment with which a container nose portion in the inlet can be forcibly engaged to cause release of gas from the container, and flow controlling means adapted to allow gas to pass from a gas container to a vessel being pressurised in use of the device and to prevent depressurisation of the vessel, through the device, when the container is removed from the inlet, said insert being readily removable in order that another insert can be substituted therefor which is suited to another form of gas container.

To enable removal of the insert, there may be a transverse slot in the insert into which a screwdriver blade, or other tool, can be inserted.

There now follows a detailed description, to be read with reference to the accompanying drawings, of an inlet device which illustrates the invention by way of example.

In the accompanying drawings: Figure 1 is a view in longitudinal section through the device; and Figure 2 is a view in longitudinal section through an alternative insert for the device.

The device comprises a tubular body 10 comprising attachment means 1 2 whereby it can be secured in an aperture in the wall of a pressure vessel in the form of a keg for use in domestic brewing. An outer end portion 14 of the device is externally threaded to enable it to be coupled up with an internally-threaded connecting portion of a pressurised gas cylinder.

The body 10 is bored through from an inlet end to provide three co-axial bores 1 6, 1 8 and 20 of successively decreasing diameter.

The first bore 1 6 comprises a threaded inner end portion 22 and defines an inlet 24 adapted to receive a nose portion of a gas cylinder. An O-ring seal 26 is located within a groove in the body 10 to project into the inlet 24 adjacent the inlet end of the body, the seal being provided to seal against a cylinder nose portion introduced into the inlet.

An externally-threaded, generally cylindrical, insert 28 is threadedly mounted in the threaded inner end portion 22 of the first bore 16. The insert comprises an O-ring seal 30 located in a groove in the insert to seal against the wall of the bore 16. A diametrically-extending slot 32 is provided in an exposed surface 33 of the insert facing the inlet 24, to enable insertion and removal of the insert by means of a screwdriver. The insert provides an abutment with which a container nose portion in the inlet can be forcibly engaged, by screwing together the cylinder and the device, to cause depression of a valveactuating plunger of the cylinder to cause release of gas from the cylinder. An axial passage 34 in the insert allows the gas from the cylinder to pass through the insert.

The device comprises flow controlling means adapted to allow gas to pass from a gas cylinder to a keg being pressurised in use of the device and to prevent depressurisation of the keg, through the device, when the cylinder is removed from the inlet 24. The flow controlling means comprises a piston-like valve member 36 which is urged by a compression spring 38 in the second bore 1 8 to compress an O-ring seal 40 against an inner surface of the insert 28 around the passage 34. The spring 38 seats against a shoulder between the second bore 18 and the third bore 20. The flow controlling means comprises also a safety valve arrangement comprising an elastic band 42 which encircles the body 10 to close an escape passage 44 leading through the body 10 from the third bore 20.

In use of the device, a gas cylinder is screwed on to the device until gas is released from the cylinder. With a keg (with which the device is associated) in need of pressurisation, the gas pressure from the cylinder displaces the valve member 36 to relieve the O-ring seal 40 and allow gas to pass through the device to the keg. When pressurisation is complete the cylinder can be unscrewed from the device, the cylinder plunger thus being released to shut off the escape of gas from the cylinder. Should the keg at any time tend to become over-pressurised, gas can escape past the elastic band 42 at whatever pressure is predetermined by the elasticity of the band.

Not all gas containers have the same form of gas-releasing arrangement, and accordingly it can be desirable to substitute for the insert 28 an insert of another form. The insert 28 is readily removable from the device and an alternative insert 28' is shown in Fig. 2, that insert being suitable for use with a gas cylinder which comprises a breakable seal which must be pierced to release gas from the cylinder. The insert 28' comprises a piercing tube 46 mounted in an axial passage 34' to project from an exposed surface 33', a portion of the tube 46 projecting from the surface 33' being cut off at its end at an angle to provide a piercing edge 48. The insert 28' comprises a diametrically-extending slot 32' (extending to each side of the projecting portion of the tube 46) to enable the insert to be inserted and removed from the device by means of a suitable tool.

Claims (7)

1. An inlet device suitable for use in association with a pressure vessel to enable gas to be introduced as required into the vessel from a pressurised gas container, the device comprising means defining an inlet adapted to receive a nose portion of a gas container, a threadedly mounted removable insert providing an abutment with which a container nose portion in the inlet can be forcibly engaged to cause release of gas from the container, and flow controlling means adapted to allow gas to pass from a gas container to a vessel being pressurised in use of the device and to prevent depressurisation of the vessel, through the device, when the container is removed from the inlet, said insert being readily removable in order that another insert can be substituted therefor which is suited to another form of gas container.

2. A device according to claim 1 in which to enable removal of the insert there is a transverse slot in the insert into which a screwdriver blade, or other tool, can be inserted.

3. A device according to either of claims 1 and .2 in which the insert comprises an O-ring seal to seal against the wall of a bore in which it is mounted.

4. A device according to any one of claims 1 to 3 in which the insert is suitable for use with a gas cylinder which comprises a breakable seal which can be pierced to release gas from the cylinder, the insert comprising a piercing tube arranged to break the seal.

5. An inlet device constructed and arranged substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

6. An inlet device constructed and arranged substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings, the insert of Fig. 2 having been substituted for the insert of the device shown in Fig. 1.

7. Apparatus suitable for use in association with a pressure vessel to enable gas to be introduced as required into the vessel from a pressurised gas container, the apparatus comprising gas-conducting means defining an inlet adapted to receive a nose portion of a gas container, a screw-threaded insert adapted to be threadedly mounted in said gas-conducting means to provide an abutment with which a container nose portion in the inlet can be forcibly engaged to cause release of gas from the container, and flow controlling means which in association with said gas-conducting means and said insert is adapted to allow gas to pass from a gas container to a vessel being pressurised in use of the apparatus and to prevent depressurisation of the vessel, through the apparatus, when the container is removed from the inlet, said insert when mounted in said gas-conducting means being readily removable in order that another insert can be substituted therefor which is suited to another form of gas container.