Valve

A valve includes a valve body having an inlet for fluid communication with a space or source containing pressurised gas, and at least one outlet. A membrane is arranged between the inlet and the at least one outlet. A membrane puncturing element is arranged for movement between a retracted, inoperative position and an extended position in which it punctures the membrane. An actuating piston is operatively coupled to the membrane puncturing element for moving the membrane puncturing element between its retracted and its extended positions, the actuating piston being received in a piston bore of the valve body. The valve body also includes a cartridge receiving chamber for receiving a sealed actuating gas cartridge. A cartridge puncturing device is provided for puncturing the actuating gas cartridge. An actuating gas flow passage communicates actuating gas released from the actuating gas cartridge to the actuating piston bore upon puncturing the actuating gas.

FOREIGN PRIORITY

This application claims priority to European Patent Application No. 18461610.0 filed Sep. 21, 2018, the entire contents of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to valves, and in particular but not exclusively to inflation valves.

BACKGROUND

Inflation valves are used in a wide range of applications, for example in inflating emergency evacuation slide systems for aircraft, life rafts and other inflatable devices.

One valve used in these applications is disclosed in U.S. Pat. No. 6,260,570 B. Inflation gas is released from a pressurised gas source though the valve which comprises a rupturable membrane. The membrane is ruptured by a spring loaded puncturing needle which is operated by a pull cable which releases a trigger ball which in turn releases the needle which punctures the membrane under the force of its spring. This type of release mechanism may, however, be sensitive to spring relaxation

SUMMARY

From one aspect, the disclosure provides a valve which comprises a valve body comprising an inlet for fluid communication with a space or source containing pressurised gas, and at least one outlet. A membrane is arranged between the inlet and the at least one outlet. A membrane puncturing element is arranged for movement between a retracted, inoperative position and an extended position in which it punctures the membrane. An actuating piston is operatively coupled to the membrane puncturing element for moving the membrane puncturing element between its retracted and its extended positions. The actuating piston is received in a piston bore of the valve body. The valve further comprises a cartridge receiving chamber for receiving a sealed actuating gas cartridge and a cartridge puncturing device for puncturing the actuating gas cartridge. An actuating gas flow passage communicates actuating gas released from the actuating gas cartridge to the actuating piston bore upon puncturing the actuating gas cartridge for moving the actuating piston and thus moving the membrane puncturing element from its retracted to its extended position.

The actuating gas flow passage may comprise an annular plenum extending around the axis of the actuating piston bore. At least one feed passage may extend from the annular plenum to the actuating piston bore.

Various embodiments may include a plurality of feed passages circumferentially spaced around the axis of the actuating piston bore.

The plurality of feed passages may be circumferentially equi-spaced around the axis of the actuating piston bore.

The actuating piston may be biased into contact with an end of the actuating piston bore by a biasing spring.

The actuating gas flow passage may enter the actuating piston bore adjacent one end of the actuating piston bore.

A face of the actuating piston facing the end of the actuating piston bore may be crowned so as to form an annular chamber between the actuating piston and the end of the actuating piston bore and the actuating gas flow passage may be connected to the annular chamber.

The end of the actuating piston bore may be formed by a plug mounted within an opening of the valve body,

The cartridge receiving chamber may be arranged transversely to the axis of the actuating piston.

The valve body may be additively manufactured.

The actuating gas cartridge puncturing device may comprise a spring loaded needle.

The valve may further comprise an actuating gas cartridge arranged in the cartridge receiving chamber. The actuating gas may be carbon dioxide.

The disclosure also provides an inflation device comprising a valve in accordance with the disclosure and a source of inflating gas, for example a cylinder of inflating gas, coupled to the inlet of the valve.

The disclosure also provides a method of inflating an inflatable device comprising:

puncturing a membrane arranged in a flow path between a source of inflating gas and the inflatable device by moving a membrane puncturing element from a retracted, inoperative position, to an extended, rupturing position, the movement of the membrane puncturing element to the extended position being effected by releasing actuating gas from an actuating gas cartridge (into an actuation piston bore which receives an actuating piston to which the membrane puncturing element is operatively coupled.

DETAILED DESCRIPTION

With reference toFIG. 1, an inflation device2in accordance with the disclosure comprises a source of inflating gas4and an inflation valve6mounted to the source of inflating gas2. In the embodiment illustrated, the source of inflating gas is a cylinder containing pressurised gas, for example carbon dioxide. The inflation valve4selectively communicates inflation gas from the cylinder4to a device (not shown) to be inflated.

As can be seen fromFIG. 2, the inflation valve6comprises a valve body8which in this embodiment is mounted to a neck portion10of the inflating gas cylinder2by means of a threaded connection12.

The valve body8comprises an inlet passage14having an inlet15for fluid communication with the cylinder4, and at least one outlet passage16having an outlet17, in this embodiment, two outlet passages16, for fluid communication with the device to be inflated. In some embodiments, the outlet passages16may be connected to the device through respective pipes (not shown) or they may simply exhaust directly into the device. For example in some embodiments, the outlet passages16may be threaded for connection to hoses or other pipes conducting the inflation gas to the device. Also, while two outlet passages16are shown, one of the outlet passages16may be plugged to provide just a single outlet for inflation gas.

The inlet passage14and the outlet passages16are fluidly connected by passages18defined within the valve housing8as will be described further below.

A rupturable membrane20, for example a metallic disc, is arranged in the inlet passage14between the inlet15and the at least one outlet passage16. In this embodiment, the rupturable membrane20is received on a shoulder22of the inlet passage14and retained in position on the shoulder22by an externally threaded annular retainer24which engages an internally threaded portion26of the inlet passage14. A seal28, for example an O-ring seal28, may be received between the shoulder22and the rupturable membrane20.

The inflation valve4further comprises a membrane puncturing element30. In the illustrated embodiment, the membrane puncturing element30is a hollow needle, but in other embodiments, the membrane puncturing element30may be a pin, spike or the like. The membrane puncturing element30is, as will be described further below, arranged for movement between a retracted, inoperative position and an extended position in which it punctures the rupturable membrane20.

The membrane puncturing element30is coupled to an actuating piston32by means of a shaft34. The actuating piston32is received in a piston bore36defined in the valve housing8. A seal, for example an O-ring seal33may be provided around the head of the piston32to improve sealing of the piston32within the piston bore36. The piston shaft34extends through a guide channel38which opens into an enlarged diameter bore section40of the inlet passage14. The passages18extend between the bore section40and the closed ends of the outlet passages16.

The piston32is urged upwardly, away from the rupturable membrane20, by means of a biasing member42, in this embodiment a coil spring42. One end44of the spring42may, as shown, be located in an annular groove46formed in an upwardly facing surface48of the piston bore36. The other end50of the spring42may, as shown, be received within a recess52formed in the lower face54of the actuating piston32.

The upper surface56of the actuating piston32is, in this embodiment, domed or crowned, i.e. its central region58is raised relative to its peripheral region60. Thus, as shown, the upper surface56may in certain embodiments be generally frusto-conical in shape. In other embodiments, the upper surface56may be curved or stepped for example.

The piston bore36is closed at its upper end62by a plug64. The upper end62of the piston bore36and the plug may be threaded, as shown. A seal ring66may also be provided, as shown, between the piston bore36and the plug64. The lower surface68of the plug64is generally planar.

In the retracted position of the membrane puncturing needle illustrated inFIG. 2, the actuating piston32is biased into contact with the lower face68of the plug64. The effect of the crowning of the upper surface56of the actuating piston32is that it creates an annular chamber70between the upper surface56of the actuating piston32and the lower surface68of the plug64. This chamber70has a maximum height at its periphery, becoming shallower towards the axis B of the actuating piston32.

Turning now toFIG. 4, the valve body8further comprises an actuating gas cartridge receiving chamber80. In this embodiment, the actuating gas receiving chamber80is arranged with its longitudinal axis A transversely to the axis B of the actuating piston32, in particular perpendicular thereto. In other embodiments, however, the actuating gas cartridge receiving chamber80may be arranged such that its axis A is arranged at another orientation relative to the actuating piston axis B, for example generally parallel thereto.

The actuating gas cartridge receiving chamber80receives an actuating gas cartridge82. This cartridge82may be a carbon dioxide cartridge, for example. Such cartridges, which may comply with standard SAE AS6011, are widely used in inflating devices such as life jackets and are sealed cartridges containing a known mass of gas at a known pressure. For example, the cartridge may be a Type II, 12 gram capacity carbon dioxide bullet.

One end84of the actuating gas receiving chamber80is closed by a removable plug86, which allows insertion of the actuating gas cylinder82into the actuating gas receiving chamber80. The other end88of the actuating gas receiving chamber80is closed by an actuating gas cartridge puncturing device90which will be discussed further below. The actuating gas cartridge82is biased towards the plug86by a spring92acting on a collar94which engages around the neck96of the actuating gas cartridge82.

An actuating gas flow passage100is formed through the valve body8for communicating actuating gas released from the actuating gas cartridge82to the actuating piston bore36upon puncturing the actuating gas cartridge82, so as to move the actuating piston32to move the membrane puncturing element needle30from its retracted to its extended position.

The actuating gas flow passage100comprises an annular plenum102formed around the actuating piston bore36and a connecting passage104extending between the annular plenum102and the actuating gas receiving chamber80. As can best be seen inFIG. 3, at least one, in this embodiment ten, feed passages106extend from the annular plenum102to the piston bore36. The feed passages106may be circumferentially spaced around the piston bore36. In this embodiment, the feed passages106are circumferentially equi-spaced around the piston bore36. An advantage of this particular arrangement is that it allows actuating gas to be evenly distributed about the entire periphery of the actuating piston32, thereby reducing out of axis forces on the actuating piston32. In some embodiments, the sum of the cross-section surfaces area of the feed passages shall be not smaller than that of the actuating gas flow passage100. This helps avoid or mitigates a reduction in the pressure or flow rate of gas into the annular chamber70.

As can be seem fromFIG. 2, the feed passages106enter the piston bore36at the annular chamber70adjacent the upper end62of the piston bore36.

As discussed above, one end88of the actuating gas receiving chamber80is closed by an actuating gas cartridge puncturing device90. Details of this actuating gas cartridge puncturing device90can be seen inFIGS. 4 and 5.

In this embodiment, the actuating gas cartridge puncturing device90comprises a cartridge puncturing element, for example a needle110mounted on a rod112having an annular groove114formed at an end116opposite the cartridge puncturing needle110. The rod112is mounted in an element118mounted, for example threadedly mounted, in the end88of the actuating gas receiving chamber80.

The element118receives a guide sleeve120for guiding the rod112. The rod112has an annular flange122, and a coil spring124is mounted between the flange122and the guide sleeve120so as to bias the puncturing needle110towards the top of the actuating gas cartridge82. The cartridge puncturing needle110is retained in an unextended position by means of a retaining element126attached to a strap127and engaging in the annular groove114in the rod112.

The retaining element126is generally spherical in shape and is received in a housing128mounted to the guide sleeve120. The housing128comprises a wall130having an opening132for receiving the retaining element126. The retaining element126is retained, under the biasing force of the spring124, between an end of the guide sleeve120and a washer134which is attached to the end116of the rod112by means of a circlip138. The washer134is dished, as can be seen most clearly inFIG. 5. This dishing resists the removal of the retaining element126from the housing128such that the use will have to apply a predetermined force to the strap127to release the retaining element126.

Having described the structure of the inflation valve6, its mode of operation will now be described.

In the normal, unoperated condition illustrated inFIGS. 1, 2, 4 and 5, the cartridge puncturing needle110and the membrane puncturing needle30are retracted by virtue of their respective biasing springs124,42. When it is desired to inflate the device, the strap127is pulled, thereby removing the retaining element126from the valve6. This in turn releases the cartridge puncturing needle110, which moves under the force of its biasing spring124to puncture the tip of the actuating gas cartridge82.

This releases actuating gas from the actuating gas cartridge82which then flows through the flow passage100to enter the annular chamber70formed at the top of the piston bore36. The pressure of the actuating gas is sufficiently high to move the actuating piston32downwardly against the force of the spring42, thereby causing the membrane puncturing element30to move downwardly and puncture the membrane20. Inflating gas can then flow from the cylinder4through the inlet passage14to the outlet passages16of the valve6and from there to the device to be inflated.

The use of an actuating gas cartridge82rather than a spring to operate a membrane puncturing element30in embodiments of the disclosure is advantageous in that the operation of the needle is not subject to spring relaxation. As a sealed cartridge is used, a reliable, consistent operating pressure will be produced, providing a reliable, consistent movement of the membrane puncturing element30. The device is thus essentially maintenance free.

The valve body8may be made in a number of ways. In some embodiments, the valve body8may be made by an additive manufacturing technique. This is advantageous as it will allow small, intricately shaped passages, such as the feed passage106to be formed through the valve body8. Small passages may allow a low pressure drop between the inflating gas cartridge82and the piston bore36. In other embodiments, the valve body8may be machined from a single piece of material or assembled from a number of discrete components.

It will be understood that modifications may be made to the exemplary embodiment described above without departing from the scope of the disclosure.

In some embodiments, for example, the flow passage100may be simplified, and a single flow passage100may enter the piston bore36, rather than a plurality of feed passages106. There may be more or fewer feed passages106than those illustrated.

Also, other actuating gas cartridge puncturing devices90may be envisaged. For example, a fixed actuating gas cartridge puncturing needle may be provided and the cartridge82may be movable within the actuating gas cartridge receiving chamber80into contact with the puncturing needle. In other embodiments, the actuating gas cartridge puncturing device90may be moved by hand or by an electromagnetic element such as a solenoid.

Also, while the disclosure has been described in connection with inflation devices, the mechanism valve disclosed could be used in other applications where release of a high pressure gas from a source is required. This applies not only to situations where a source of gas is provided for a specific purpose such as for inflating devices as discussed above, but in other systems where a rapid depressurisation of a space is required. In that event, the valve6may be installed in a wall or outlet of a space, the puncturing of the membrane30releasing gas from the space.