Valve for an inflatable structure

A valve comprising a valve body having an inlet and an outlet; a valve member moveable in a linear direction with respect to the valve body between a closed condition in which flow between the inlet and the outlet is restricted and an open condition; and an actuator coupled to the valve member such that the valve member is constrained to rotate with the actuator and is movable in the linear direction with respect to the actuator, wherein the valve is configured such that rotation of the actuator causes the valve member to move in the linear direction with respect to both the actuator and the valve body between the closed condition and the open condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to British (GB) Patent Application No. 1120400.5 filed on 25 Nov. 2011, and to British (GB) Patent Application No. 1120872.5 filed on 5 Dec. 2011. British (GB) Patent Application No. 1120400.5 and British (GB) Patent Application No. 1120872.5 are hereby incorporated by reference in their entireties for any and all purposes.

BACKGROUND

This invention relates to a valve for an inflatable structure, and particularly, although not exclusively, relates to a transfer valve for an inflatable craft.

Inflatable craft, such as boats, often comprise multiple chambers. The chambers are isolated from each other such that deflation of one chamber, for example as a consequence of a leak, does not result in deflation of the other chambers.

A problem associated with such craft is that prior to and after use of the craft, each chamber must be inflated/deflated independently of the others.

It is known to use valves, such as those disclosed in U.S. Pat. No. 6,178,911 to connect the chambers. The valves are opened during controlled inflation or deflation of the vessel, but are closed during use of the craft so that the chambers are isolated from each other. Consequently, a leak in one chamber does not cause deflation of the other chambers.

Known valves are difficult to operate, install and maintain.

SUMMARY

According to a first aspect of the present invention there is provided a valve comprising: a valve body having an inlet and an outlet; a valve member moveable in a linear direction with respect to the valve body between a closed condition in which flow between the inlet and the outlet is restricted and an open condition; and an actuator coupled to the valve member such that the valve member is constrained to rotate with the actuator and is movable in the linear direction with respect to the actuator, wherein the valve is configured such that rotation of the actuator causes the valve member to move in the linear direction with respect to both the actuator and the valve body between the closed condition and the open condition. The closed condition may be a condition in which flow between the inlet and the outlet is prevented.

The valve may comprise a first stop which prevents continued rotation of the actuator with respect to the valve body when the valve member is moved into the open condition, and a second stop which prevents continued rotation of actuator with respect to the valve body when the valve member is moved into the closed condition.

The first and second stops may be arranged such that the valve member is displaced between the open condition and the closed condition by rotating the actuator through less than one revolution with respect to the valve body, for example through not more than half a revolution or through not more than a quarter of a revolution.

The valve member may be arranged with respect to the housing such that rotation of the valve member with respect to the housing causes the valve member to move in the linear direction. The actuator may be arranged with respect to the valve body such that the actuator is constrained with respect to the valve body in the linear direction.

The valve may comprise a bias which is arranged to bias the valve member into the closed condition. The bias may comprise a resilient member disposed between the valve member and the actuator.

A passage may be provided through the valve member, the passage being arranged such that when the valve member is in the open condition, the inlet and the outlet are in fluid communication with each other through the passage. The passage may have an inlet port which is aligned with the inlet when the valve member is in the open condition and is obstructed by the valve body when the valve member is in the closed condition.

The actuator may comprise a cap which is manually rotatable.

The valve body may comprise a first part and a second part which are arranged to clamp a portion of a wall of an inflatable structure between the first part and the second part thereby securing the valve to the inflatable structure. The first part and second part may be configured to seal the valve to the inflatable structure.

The first part may comprise the inlet and the outlet and the second part may support the actuator for rotation with respect to the valve body, the valve member being arranged with respect to the actuator and the second part of the valve body such that the position of the valve member in the linear direction with respect to the first part of the valve body is maintained when different thicknesses of wall of an inflatable structure are clamped between the first part and the second part of the valve body.

The valve may further comprise a locking feature which is arranged to releasably lock the valve member in the open condition.

According to a second aspect of the present invention there is provided an inflatable structure comprising: first and second chambers, and a valve in accordance with the first aspect of the invention, the valve being arranged such that the inlet is disposed within the first chamber, wherein the first chamber and second chamber are in fluid communication with each other through the valve.

At least a portion of the valve may extend through a wall of the first chamber such that the actuator is actuable from outside of the inflatable structure.

The valve outlet may be connected to the second chamber by a collapsible tube, wherein a resilient spacer extends along at least part of the tube to resist collapsing of the tube. The resilient spacer may comprise a helical spring.

According to a third aspect of the present invention there is provided a connector comprising a valve in accordance with the first aspect of the invention, wherein the connector further comprises a fastener and a tube extending between the valve and the fastener.

The connector element may comprise a fastener body which is arranged to be fixed to a wall of an inflatable structure and a latching element which is connected to the tube, wherein the fastener body and the latching element comprise corresponding fastening features which are configured to provide a snap-fit connection between the fastener body and the latching element. The latching element may be configured such that it is rotatable with respect to the fastener body when the latching element is latched to the fastener body. The latching element may be resilient.

According to a fourth aspect of the invention there is provided a method of inflating an inflatable structure in accordance with the second aspect of the present invention, wherein the method comprises: opening the valve; supplying gas to the first chamber or second chamber to inflate both the first and second chambers; and closing the valve to isolate the first chamber from the second chamber.

According to a fifth aspect of the invention there is provided a method of deflating an inflatable structure in accordance with the second aspect of the present invention, wherein the method comprises: opening the valve; and expelling gas from the first chamber or second chamber into the other of the first and second chambers.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1shows part of an inflatable structure2, such as an inflatable craft, comprising an outer wall4, a baffle6and a connector8.

The baffle6is arranged with respect to the outer wall4such that the baffle6divides the inflatable structure2into a first chamber10and a second chamber12. The chambers10,12are hermetically sealed from each other by the baffle6.

The connector8connects the first chamber10with the second chamber12. The connector8provides fluid communication between the chambers10,12.

As shown inFIGS. 2 and 3, the connector8comprises a valve14, which is a transfer valve, a fastener16and a collapsible tube18along which a resilient spacer20in the form of a helical spring extends. The collapsible tube18may be made of a suitable flexible material.

FIG. 4shows the valve14. The valve14comprises a valve body22, a valve member24, in the form of a piston, and an actuator26. The valve member24is arranged such that it is displaceable in a linear direction with respect to both the valve body22and the actuator26.

The valve body22is substantially cylindrical. The valve body22comprises a first part28and a second part30.

A bore32extends through the first part28in the longitudinal direction of the valve body22. The first part28comprises a plurality of inlet passages36which extend radially from the bore32. The passages36provide fluid communication between the first chamber10and the bore32. The passages36are spaced circumferentially about the periphery of the first part28.

One end of the bore32provides a valve outlet38which is in fluid communication with the inlet passages36via the bore32. The other end of the bore32comprises a threaded portion40for receiving the second part30of the valve body.

The bore32comprises first and second shoulders42,44which are disposed between the inlet passages36and the valve outlet38. A first stepped section46of the bore32is defined between the shoulders42,44. A second stepped section48of the bore32is defined between second shoulder44and the outlet38. The diameter of the first stepped section46is greater than the diameter of the second stepped section48.

The second part30of the valve body22comprises a second longitudinally extending bore50. The second part30comprises an externally threaded portion52at one end and a radially extending flange54at the other end.

The threaded portion52corresponds to the threaded portion40of the first part28. The threaded portion52extends through an opening provided in the outer wall4of the inflatable structure2and engages with the threaded portion40of the first part28.

The flange54extends radially outwardly such that it extends over the end of the first part28. The flange54and the first part28are disposed on opposite sides of the outer wall4such that the outer wall4is sandwiched between the flange54and the first part28. The flanged portion54is held by the threaded portions40,52in pressing engagement with the first part28thereby clamping and sealing the valve14to the outer wall4.

The valve member24comprises a disc-shaped middle portion58, a restrictor portion60and a keyed portion62. The restrictor portion60and the keyed portion62extend away from the middle portion58in opposite directions. The restrictor portion60extends into the first stepped section46of the bore32.

The restrictor portion60comprises a cylindrical wall64which extends longitudinally from the periphery of the middle portion58. The wall64defines a flow passage65through the restrictor portion60. Ports66are provided through the wall64. The ports66are spaced circumferentially about the wall64. The ports66and flow passage65are arranged to provide fluid communication between the inlet passages36and the outlet38through the restrictor portion60.

Two diametrically opposed slots68are also provided in the wall64. The slots68extend circumferentially and longitudinally with respect to the wall64. A pin70extends through the slots68and across the bore32. The pin70is held captive at each end by the first part28of the valve body22. The pin70and slots68are arranged such that when the valve member24is rotated within the bore32with respect to the valve body22, the edges of the slots68slide over the pin70thereby driving the valve member24in the longitudinal direction of the bore32. The valve member24is drivable between an open position in which the ports66are aligned with the passageways36and a closed position in which the ports66are obstructed by the surface of the first section46of the bore32.

The middle portion58comprises a seal78which extends about the periphery of the middle portion58. The seal78is arranged to seal against the surface of the first section46of the bore32when the valve member24is in the closed position.

In the open position the inlet passages36and the outlet38are in fluid communication with each other through the valve member24. It will be appreciated that in the open position, the ports66may not be completely aligned with the passageways36. The ports66may, for example, be offset from the passageways36as shown inFIG. 4. In the closed position the valve member24prevents fluid flow between the inlet passages36and the outlet38.

The valve member24and part of the actuator26are shown in more detail inFIGS. 8 to 10.

The slots68are configured such that the valve member24is moved from the closed position to the open position by rotation of the actuator26through a quarter of a revolution. The respective ends of the slots68provide stops that provide positive indication that the valve member24is in the open or closed position.

The end of each slot68nearest the outlet38comprises a locking feature69for locking the valve member24in the open position. The locking feature69comprises a notched portion at the end of each slot68, which receives the pin70such that the pin70inhibits movement of the valve member24from the open condition. Alternatively, the locking feature may be a portion of each slot68which extends perpendicularly to the direction of linear motion of the valve member24, for example a portion of each slot68which extends only in the circumferential direction.

The keyed portion62comprises a wall72which extends from the middle portion58. The wall72defines a cavity76. The outer surface of the wall72comprises a keying feature74, for example profiled surfaces of the wall72. In the embodiment shown, the keying feature74comprises diametrically opposed flats forming the outer surface of the wall72for engagement with the actuator26. Alternatively, the keying feature74may comprise a spline. The keyed portion62further comprises a cylindrical section77at the end of the keyed portion62, which has a peripheral guide surface.

The actuator26comprises a drive part80and a cap82. The drive part80comprises two arms81for receiving the keyed portion62. The arms81define engagement surfaces83which slidably engage with the flats of the keying feature74so as to constrain the valve member24to rotate with the actuator26. The arms81further define respective grooves84which extend along the length of each arm81to slidably receive the cylindrical section77of the keyed portion62of the valve member24. The grooves84have respective curved surfaces which correspond to the curvature of the outer surface of the cylindrical section77. The grooves84and the cylindrical section77axially align the valve member24with the actuator26.

Alternatively, the drive part may comprise a bore which comprises a keying feature that corresponds to a keying feature of the keyed portion, wherein the keying feature and the bore interlock to constrain the valve member to rotate with the actuator and axially align the valve member and the drive part.

The sliding arrangement of the keyed portion62with respect to the arms81of the drive part80allows the valve member24to move linearly with respect to the actuator26.

A seal88is provided about the periphery of the drive part80and seals against the second part30of the valve body22.

The cap82is secured to the drive part80by a screw, or similar fastener, such that the cap82and the drive part80are constrained to rotate together. The cap82extends radially outwardly of the drive portion80. A first retainer90, such as a circlip, is provided on the drive part80to prevent the drive part80from being withdrawn from the second part30of the valve body22. The drive part80further comprises a rib91and a second retainer93, such as a washer, disposed between the rib91and the first retainer90. The first retainer90, rib91and second retainer93together prevent linear displacement of the actuator26with respect to the second part30of the valve body22. The cap82may be shaped or marked so that the orientation of the cap82with respect to the valve body22or the outer wall4of the inflatable structure2can be readily determined.

A resilient bias in the form of a compression spring92is disposed between the actuator26and the valve member24. The spring92is accommodated by the cavity76and a counter bore in the drive portion80. The spring92acts on both the actuator26and the valve member24to urge the valve member24away from the actuator26into the closed position.

FIGS. 5 and 6show the fastener16. The fastener16comprises a fastener body94, a fastener cap96and a latching element98.

The fastener body94is cylindrical. The fastener body94has an externally threaded portion100at one end and a radially extending flange102at the other. The threaded portion100extends through an opening in the baffle6.

The fastener cap96comprises a bore104having a threaded portion106which corresponds to and engages with the threaded portion100of the fastener body94. The flange102and the fastener cap96are disposed on opposite sides of the baffle6such that the baffle6is sandwiched between the flange102and the fastener cap96. The flange102is held in pressing engagement with the fastener cap96by the threaded portions100,106thereby clamping and sealing the fastener16to the baffle6.

The latching element98is cylindrical and extends through the fastener body94. The latching element98comprises longitudinally extending prongs108at one end. In the embodiment shown there are four prongs108which are spaced apart from each other in the circumferential direction. Each prong108comprises a latching feature in the form of a radially outwardly extending hook110at its end.

The latching element98further comprises a circumferentially extending rib112which extends radially outwardly of the latching element98.

The latching element98is arranged with that the fastener body94disposed between the hooks110and the rib112such that linear displacement of the latching element98with respect to the fastener body94is inhibited.

The latching element98comprises a resilient material which allows for each prong108to be deformed radially inwardly.

An elbow connector114is fitted onto the end of the latching element98opposite the prongs108and secures the fastener16to the tube18. The elbow connector114has a turn through angle of 45 degrees. The elbow connector114comprises a serrated fitting116onto which an end of the tube18is secured. It will be appreciated that an elbow connector114having a turn-through angle between 0 degrees and 90 degrees could be used.

The fastener16can be attached to the baffle by first clamping baffle6between the fastener body94and the fastener cap96. The latching element98is then inserted into the fastener body94such that the fastener body94deforms the prongs108radially inwardly as they are inserted into the body94. Once located in position, the prongs108snap back into a nominal shape. The hooks110engage with the end of the fastener body94to inhibit removal of the latching element98from the fastener body94. The advantage of such a fastener16is that the body94and the cap96can be pre-fitted without the latching element98. The latching element98, to which the tube18and valve14can be pre-fitted, can then be attached making assembly of the connector8with the inflatable structure2less cumbersome. Once fitted, the latching element98is rotatable with respect to the fastener body94.

As shown inFIG. 7, the connector8accommodates deformation of the baffle6during inflation, deflation and during use of the inflatable structure2when inflated. It will be appreciated that the fastener16can be attached to the baffle6at any convenient location.

The valve14, which may be fitted before connecting the fastener16, is assembled as part of the inflatable structure2by clamping the outer wall4of the inflatable structure2between the first and second parts28,30of the valve body22. As described previously, the actuator26is fixed linearly with respect to the second part30of the valve body22. Consequently, the position of the actuator26will vary in accordance with the thickness of the wall4to which the valve14is attached. The slidable arrangement of the keyed portion62of the valve member24with respect to the drive part80of the actuator26allows for displacement of the valve member24with respect to the actuator26in order to accommodate different thicknesses of wall4without affecting the position or stroke of the valve member24with respect to the first part28of the valve body22. Consequently, the valve14can be readily attached to structures having different wall thicknesses.

Prior to inflation of the inflatable structure2, the valve14is opened by manually rotating the actuator26with respect to the valve body22in an anticlockwise direction. Rotation of the actuator26causes the valve member24to rotate with the actuator26with respect to the valve body22.

The edges of the slots68slide over the pin70thereby driving the valve member24with respect to the valve body22towards the actuator26. The sliding arrangement of the keyed portion62of the valve member24and the drive part80of the actuator26accommodates linear movement of the valve member22towards the actuator26. The spring92resists movement towards the actuator26such that release of the actuator26results in the valve member24returning to the closed position. The first retainer90, rib91and second retainer93prevent the actuator26from being displaced linearly with respect to the valve body22. Components of the actuator26do not therefore become exposed when the valve is opened which means there is less likelihood of damage to the valve14.

The linear motion of the valve member24, with respect to the valve body22, moves the seal78out of sealing engagement with the first section46of the bore32and moves the ports66into alignment with the inlet passages36. The inlet passages36are therefore in fluid communication with the valve outlet38through the valve member24.

Once the pin70reaches the end of one or both of the slots68, further rotation of the valve member24is prevented by the ends of the slots68acting against the pin70. This positive indication that the valve member24is in the open position makes it easy for the operator of the valve14to determine that the valve14is open. Furthermore, restricting rotation of the actuator to less than one revolution in order to move the valve member24between the closed position and the open position enables the condition of the valve member24to be readily determined. For example, the cap82may be provided with visual or tactile features which enable the position of the actuator26, and hence the condition of the valve member24, to be determined by visual inspection of the actuator26or by touch. The locking features69at the ends of the slots68retain the valve member24in the open position. In particular, the locking feature69prevents the valve member24from being moved from the open position by the force exerted by the spring92on the valve member24in the longitudinal direction of the valve member24. The actuator26can therefore be released by the operator during inflation of the inflatable structure2without the valve member24being automatically returned to the closed position by the action of the spring92.

The inflatable structure2is inflated by supplying gas (for example air, carbon dioxide or a mixture containing nitrogen) to the first chamber10, for example through an inlet valve (not shown) in the outer wall4of the chamber10. Gas passes from the first chamber10through the inlet passages36, through the ports66, passage65, outlet38and into the tube18. The gas passes along the tube18through the fastener16and into the second chamber12. The spring20disposed within the tube18ensures that the tube18does not become kinked, flattened or excessively twisted which would inhibit fluid communication, and therefore passage of gas, through the tube18.

Once the inflatable structure2is inflated, the valve14is closed by manually rotating the actuator26with respect to the valve body in the clockwise direction. The valve member24is driven against the pin70which drives the valve member24away from the actuator26into the closed position. The ports66are therefore moved out of alignment with the inlet passages36and into the first section46. At the same time, the seal78is moved into sealing engagement with the surface of the first section46of the bore32thereby sealing the inlet passages36from the outlet38. Flow of fluid between the inlet passages36and the outlet38is therefore prevented. The first and second chambers10,12are therefore isolated from each other by the valve14.

The valve14can be re-opened to deflate the structure2though the first chamber10.

It will be appreciated that the valve14, fastener16and tube18could be used together or independently of each other. The valve14, fastener16and/or tube18could be used in other types of inflatable structures, such as inflatable tents.

It will be appreciated that gas could be supplied to the second chamber12and from the second chamber12to the first chamber10in order to inflate the inflatable structure2.