This invention relates to a holder for a gas cylinder and to apparatus for supplying a gas comprising the holder and the gas cylinder.

The term "gas cylinder" is used herein to signify a pressure vessel for storing and delivering a compressed gas, the pressure vessel having a water capacity of at least 400ml. The pressure vessel is typically but not necessarily cylindrical in shape. The gas may be a permanent gas or a non-permanent gas. If a non-permanent gas, at least a fraction of the gas will typically be in liquid state at a conventional storage pressure.

Gas cylinders have been used in industry for at least a hundred years. Traditionally, a gas cylinder has been closed by a simple valve. The valve is adapted to be opened by application of a simple key or wrench. Because the gas cylinder typically stores gas at a pressure of 200 bar or higher, it is usually necessary to regulate the pressure of the gas supply upstream of equipment in which the gas is to be used or consumed. Some conventional gas cylinder valves have a connection which enables a gas pressure regulator, and, typically, a gas pressure gauge to be fitted as additional items. All this has been known for a long time.

Relatively recently, as an alternative to the separate regulator, the cylinder valve has been modified so as to include a pressure-regulating element. Further developments include the provision in association with the cylinder valve of various electronic devices for carrying information about the cylinder or its contents, and for transmitting or displaying or converting such information. There is thus a trend for gas cylinders to have in their heads ever more sophisticated equipment.

This trend has certain disadvantages. First, cylinders are subject in use to rough handling. Electronic and other sensitive equipment is prone to damage during such handling, even if shielded by means of a cylinder cap or the like. Further, the incorporation of such equipment into the cylinder adds to its size and weight, making the cylinder more difficult to handle and can therefore reduce the number of cylinders that can be transported from a filling site to sites of use on a vehicle of given size.

According to a first aspect of the present invention there is provided a holder for a gas cylinder, the holder comprising: a) an inlet port connectible to the cylinder; b) an outlet port; c) a gas passage extending from the inlet to the outlet port; and one or both of; d) a gas pressure regulating valve in the said gas passage; and/or e) at least one electronic device for sensing, transmitting and/or displaying information relating to the cylinder or its contents, wherein the holder is self-supporting or has means which enables the holder to engage a support. By the term "gas cylinder" is meant a pressure vessel, not necessarily cylindrical in shape, adapted to the storage under pressure and delivery of a gas

According to a second aspect of the present invention there is provided a gas supply apparatus comprising a gas cylinder held in a holder according to the first aspect of the present invention, wherein the gas cylinder has a shut-off valve but no pressure regulating valve.

The shut off valve may be adapted to be opened when held in the holder according to the first aspect of the present invention. Indeed, the cylinder holder may include means for opening the shut off valve. The holder according to the first aspect of the invention is typically able to take or support the full weight of the gas cylinder.

The invention therefore makes it possible to incorporate in, or connect to, the holder not only the pressure regulator but a range of electronic devices to provide information about the contents of the cylinder or the flow of gas therefrom. Sophisticated telemetry or electronic display of information in the vicinity of the cylinder is therefore possible without adding to the complexity, propensity to damage and weight of the gas cylinder. As indicated above, the electronic devices may be incorporated in the holder or connected to the holder. The holder according to the first aspect of the present invention may incorporate in a head the gas pressure regulating valve and any said electronic device. The inlet and outlet ports may also be formed in the head.

The holder may be provided with a pair of jaws or a strap for securing the gas cylinder. The holder may additionally or alternatively have a cradle for supporting the gas cylinder.

The holder may be adapted to support the gas cylinder with the axis of the cylinder vertical or horizontal or between the horizontal and the vertical.

The holder may itself be part of or attached to a trolley.

The gas passage may house one or more valves in addition to the pressure regulating valve. The additional valve may, for example, be a check valve (also known as a non-return valve) or a demand valve.

The gas passage may additionally or alternatively house a gas flow meter.

The gas passage may further house a gas scavenging device or material. The holder according to the first aspect of the present invention may be provided with an attachment device or means to enable it to be removably attached or coupled to a wall, a bed, a wheelchair, a hanger or a trolley.

The holder according to the first aspect of the present invention may alternatively be coupled to or embody a medical device such as a humidifier, nebuliser, or pulse oximeter.

The holder according to the f irst aspect of the present invention may comprise a visible electronic display unit for displaying information about the contents of the gas cylinder, or a transponder or other transmitter for the wireless transmission to a remote site of information about the contents of the gas cylinder. The visible electronic display unit may be incorporated in, or connected to, the holder.

The holder according to the first aspect of the invention may comprise a power source such as a battery or cell for providing electrical power to an electrical device in the holder. The power source may be incorporated in, or connected to, the holder.

The inlet port of the holder according to the invention may have associated therewith coupling means of chosen configuration enabling the holder to be coupled only to any cylinder having a complementary coupling means. This arrangement makes it possible for the holder to be dedicated to a gas cylinder containing a particular chosen gas or gas mixture. Thus, only gas cylinders containing the chosen gas or gas mixture will be given a coupling means complementary to that of the holder. The coupling means of the gas cylinder may be associated with the cylinder valve, particularly an outlet port in the body of the cylinder valve. The cylinder valve may, for example, have a pin index complementary to corresponding pins on the holder.

The cylinder valve may be in accordance with any one of claims 1 to 14 of international patent application WO 2009/125180A. In such embodiments, the complementary yoke may be incorporated into the holder according to the first aspect of the present invention, for example, into a head provided on the holder.

The holder and gas supply apparatus according to the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure , is a schematic flow diagram of a first embodiment of a cylinder holder and gas supply apparatus according to the invention;

Figure 2 is a schematic flow diagram of a second such embodiment;

Figure 3 is a schematic flow diagram of a third such embodiment; Figure 4 is a schematic perspective of a first cylinder holder

corresponding to that shown in any of Figures 1 to 3; and

Figure 5 is an alternative embodiment of cylinder holder to that shown in Figure 4; and

Figures 6 and 7 illustrate front and rear views of a medical gas supply apparatus embodying a cylinder holder according to the invention. The drawings are not to scale.

Referring to Figure 1 , there is shown schematically an apparatus comprising a pressure vessel (gas cylinder) 2 containing a permanent or non- permanent gas or mixture of gases under pressure, a cylinder valve 4 (i.e. a shut off valve) and a holder 6. A pressure vessel 2 may be a conventional gas cylinder formed of steel or aluminium. Such vessels 2 are capable of withstanding internal pressures of well in excess of 200-300 bar, the cylinder walls being made of a suitable thickness so as to enable a gas or gas mixture to be stored safely at such pressure. If desired, the pressure vessel 2 can be provided with a fibrous winding for strengthening purposes. The use of such windings, permits the wall thickness to be less than in a conventional cylinder, as is well known in the art. Such fibre-reinforced pressure vessels are typically provided with an outer jacket 8 typically formed of plastics material. The outer jacket 8 protects the inner vessel or "liner" as it is sometime called, from damage by external impact. A typical example of such a lightweight pressure vessel is the subject of our corresponding International Patent Application PCT/GB 2011/001311 , filed 08 September 2011.

The cylinder valve 4 is a shut off valve typically, of conventional kind. It is capable, when closed, of retaining gas under high pressure, for example, a pressure in the range of 200-300 bar in the cylinder 2. The valve 4 has a valve member (not shown) which may be opened manually or by other means to release gas, when desired. The valve 4 has a configuration which enables the cylinder, when empty, to be filled with a gas of chosen composition.

Typically, there is fill port 12 in series with a one way valve 14 and filter 16 to enable the cylinder filling to be performed. Although not shown in Figures 1 to 3, the fill port 12, the one way valve 14 and the filter 16 may all be

incorporated in the cylinder valve 4. The cylinder holder 6 may perform a number of functions in addition to the primary one of holding the pressure vessel or gas cylinder 2. One of these functions is to provide a gas delivery means. The holder 6 has an inlet port 20 and at least one outlet port 22 with a gas passage 24 affording communication between the inlet port 20 and the outlet port or ports 22. In Figures 1 to 3, two such ports 22 are shown, but if desired there may simply be a single port 22. The or each outlet port 22 may be provided with a conventional fitting for connecting to a delivery gas pipeline (not shown).

Such fittings include fir tree connectors, barb connectors and standard quick connectors.

A pressure regulator 26 is provided in the gas passage 24. There is therefore no need to fit a separate pressure regulator to the gas cylinder 2 or to incorporate a gas pressure regulator into the cylinder valve 4. A pressure regulator 26 may comprise a single pressure reduction stage or a plurality of pressure reduction stages in order to reduce the pressure of the gas to a chosen pressure well below the maximum gas storage pressure of the cylinder 2. For example, a pressure regulator 26 may be adapted to supply gas at a chosen pressure in the range of 2 to 10 bar (absolute)

notwithstanding the fact that the storage pressure of the gas cylinder 2, when full, may be in the order of 200 bar or higher.

The cylinder holder 6 is provided with a cylinder docking station 30 about the port 20 first facilitates engagement of the cylinder 2 to the holder 6. The features of the docking station 30 are dependent on the nature of the cylinder valve 4 (shut off valve). One common kind of cylinder valve is the so- called "pin-index" valve. ISO 407 details the pin index valve outlets used specifically for medical gas service and provides unique outlets for 16 different gases and gas mixtures. The pin index system utilises a number of pin and hole positions unique for each gas, of the holes being drilled on the face of the cylinder valve 2. Accordingly, a docking station 30 may comprise a yoke (not shown) for engaging the cylinder valve 2, the yoke being provided with a configuration of pins corresponding to the arrangement of holes. Engagement of the pins with the holes causes the cylinder valve 4 to open. This

arrangement positively prevents the wrong cylinder being fitted to the holder.

In an alternative arrangement, the cylinder valve 4 may be a bull nose valve. This is another common type of cylinder valve. It is opened by engagement of a key (not shown) with a valve member (not shown), the valve being formed with a suitable slot for the insertion of the key. In a cylinder holder and apparatus according to the invention the docking station 30 may be fitted with the appropriate key. Correct engagement of the cylinder with the holder 6 causes the key to open the cylinder valve 4.

In yet another alternative, the cylinder valve or shut off valve 4 may be opened pneumatically, hydraulically or electrically instead of by the action of pins or a key. In such an arrangement as illustrated in International Patent Application WO 2009/125180 A1 , and the docking station may comprise a yoke again of the kind shown in WO 2009/ 25180 A . In such arrangements, the cylinder valve 2 is adapted to be opened by gas pressure which can be applied through a valved passage in the yoke. If desired, the valved passage may be opened by operation of a push button (not shown) provided on the holder 6. For example, the push button may either mechanically or, say, electrically, open a pilot gas valve which is provided in the holder 6. °

Referring again to Figure 1 , the passage 24 may be provided with other features in addition to the pressure regulator 26. For example, it may include a non-return valve 40 and a flow meter 42, the latter being manually adjustable from outside a holder 6. As shown in Figure 1 there may also be a plurality of outlet ports 22 in parallel with one another instead of a single port.

Referring again to Figure 1 , the holder 6 may be provided with a cylinder contents indicator 46 which can be of a conventional Bourdon tube kind and has a conventional pointer and scale arrangement in a dial 48 visible from externally of the holder.

Referring now to Figure 2, the apparatus shown therein is generally as shown in Figure 1 , except that an electronic cylinder contents indicator 50 is employed instead of the indicator 46. The electronic cylinder contents indicator 50 is shown incorporated into the holder 6. However, it will be understood that the electronic cylinder contents indicator 50 may alternatively be connected to the holder 6. Various arrangements are possible for displaying cylinder contents electronically. In one arrangement, illustrated schematically in Figure 2, the contents indicator 50 is operatively associated with pressure and temperature sensors (not shown) which can be located in the passage 24. These sensors transmit signals to a computing unit 52, which may comprise one or more microprocessors. The computing unit 52 is programmable and the holder 6 provided with an external, accessible, keypad (not shown) for this purpose. For example, the computing unit may be programmed with the composition of the gas, the gas pressure and

temperature when the cylinder was filled, and an equation of state from which the proportion of the original contents remaining can be calculated using the sensed values of pressure and temperature. A source of electrical power, typically a battery or cell 54, is operatively associated with the contents indicator 50 so as to provide necessary electrical power to the computing unit 52 and to the pressure and temperature sensors. The battery or cell 54 may also be used to provide electrical power to an LED display 56 readily visible from outside the holder 6, for displaying information about the cylinder 2 or its contents, for example, an indication of how full or how empty the cylinder is.

Other electronic functions may be incorporated in, or attached to, the holder 6 in addition to or instead of the cylinder contents indicator 50. For example, the holder 6 may comprise a transponder (not shown) which is able to relay information to a station remote from the cylinder. In medical practice, this may enable the medical practitioner to observe, say, gas flow to a patient at a central station. Thus the holder 6 may comprise sophisticated

communications technologies such as USB, radio frequency identification (RFID), Bluetooth, wireless networking (IEE 802.11) or GSM, some or all of which can be used to identify the particular cylinder and communicate data about it, or its contents, temperature, pressure, flow rate, time in use, location and/or other data to a base station, hand-held unit or even back to the cylinder owner.

The holder 6 may also comprise various alarms and alerts which may be actuated in the event of say, the gas flow rate to a user or patient diverging from a chosen flow rate or in the event of the cylinder contents becoming undesirably low. It is also possible to incorporate, or attach patient monitoring devices within or to the holder 6 and to associate these devices with an alert or alarm means. The alert or alarm means may comprise an LED or LCD device or a device for emitting an audible warning signal. The arrangements shown in Figures 1 and 2 are but examples of the various components that can be incorporated within, or attached to, an apparatus according to the second aspect of the invention. A further example is shown in Figure 3, which is generally the same as that shown in Figure 1 , save that the cylinder contents indicator 46 is now associated with the cylinder 2 rather than the holder 6. In general, however, it is preferred that the equipment connected to the cylinder, but not forming part of the holder 6 is kept to a minimum so as to facilitate the provision of a docking station in the holder for the cylinder. It is also to be understood that although Figure 1 to 3 illustrate gas cylinders provided with an outer protective jacket, this part may be omitted and the cylinder 2 is typically a conventional thick-walled cylinder.

The arrangement of holder components, as illustrated in any of Fig 1 to 3, may typically be incorporated in the head of a suitable holder.

Examples of suitable embodiments are shown in Figures 4 and 5.

Referring to Figure 4, the holder takes the form of a self-supporting vertical stand 400 comprising a pair of jaws 402 adapted to grip the body of the cylinder 2, a base 404 on which the foot of the cylinder 2 can stand and a head 406 which houses all the holder features of any of the apparatuses shown in Figures 1 to 3.

The arrangement of the jaws 402 and base 404 may be similar to or essentially the same as those disclosed in our co-pending patent application WO 2010/109206 A. In addition to the engagement of the cylinder 2 by the jaws 402, the support of the cylinder 2 by the base 404, there is engagement of the head of the cylinder 2 by the head 406 of the cylinder holder shown in Figure 4. If desired, the respective configurations of the cylinder valve 4 and the head 406 may be such that the cylinder valve clicks into place in the head 406. In some embodiments, the action of inserting the cylinder 2 within the cylinder holder 406 may of itself open the valve 4. Alternatively, the head 406, may be provided with push button or other means to cause the cylinder valve 4 to be opened. The head 406 has an inlet port, a gas passage and an outlet port (all not shown in Figure 4) analogous to the arrangement shown in Figures 1 to 3. The head 406 can readily be made of size and shape so as to accommodate all the holder devices shown in Figure 2. My LED or LCD device or any dial may be incorporated in, or attached to, the head 406 such that it is readily visible to the user of the cylinder. If desired, the stand 400 may be provided with a pair of wheels 410 so as to facilitate transport of a cylinder to a required station.

It is not necessary that the holder includes such wheels 410 or the base 404. These items are omitted from the holder shown in Figure 5. This holder is intended to be secured to a bed or rail mount. Accordingly, it has a body 502 formed with an integral hook 504 which enables it so to be secured

In the embodiment shown in Figures 4 and 5, the cylinder is held in a vertical position. This is not essential. In the embodiment shown in Figures 6 and 7 the cylinder is held horizontally. It is further to be noted that in the apparatus shown in Figures 6 and 7 the holder is incorporated into a medical device 600 used for gas delivery. In this example, the medical device 600 may, for example, be a nebuliser which employs gas stored in the cylinder 2. The device 600, may nonetheless incorporate all the holder Figures described with reference to and shown in, say Figure 2. Further, the medical device 600 typically has a connection 602 for a delivery device to a patient and a connection 604 for a sensor from the patient. The device 600 may also incorporate one or more demand valves (not shown) to ensure that gas carrying, say, a nebulised medicament is delivered during inspiration phases of a patient's breathing cycle.

The cylinder holder and apparatus according to the invention make it possible to gather and communicate selected information about the real-time contents of and flow of gas from a gas cylinder while using a relatively simple cylinder valve. This is particularly advantageous if the number of cylinders used over a period of time exceeds the number of stations at which the cylinders are used. Sophisticated monitoring equipment can be incorporated in the cylinder holder without running the risk of damage during normal cylinder handling, which risk would occur were the monitoring and other devices to be incorporated in the cylinder valve or cylinder package itself. It is also possible to include within, or attach to, the cylinder holder electrical devices that cannot be readily included within a cylinder valve or associated housing.