Valve assembly for aircraft water supply system

A valve assembly (20) for an aircraft water supply system. The valve assembly (20) comprises a valve member (40), an electrical motor (64), and a mechanical returning mechanism (80). When electrical power is provided, the motor (64) can be controlled to move the valve member (40) from a first position and to a second position. The mechanism (80) is operably connected to the valve member (40) and mechanically biases it towards the first position. If a power loss occurs when the valve member (40) is in the second position, the returning mechanism (80) non-electrically (e.g., mechanically) returns the valve member (40) to the first position.

GENERAL FIELD

An aircraft water supply system including a valve assembly with a valve member moved by an electrical motor between a first position and a second position.

BACKGROUND

An aircraft commonly includes a water supply system for providing potable water to respective outlets of various water-using devices (e.g., sink faucets, coffee brewers, toilets, etc.). An aircraft water supply system can comprise, for example, a tank and a series of plumbing lines for supplying the outlets14, filling the tank, draining the tank, and/or venting the tank. One or more valve assemblies installed in the plumbing lines for preflight, post-flight, and in-flight purposes. At least some of the valve assemblies are electrically driven so that they can be opened/closed automatically and/or remotely.

SUMMARY

A valve assembly comprises a valve member, an electrical motor that moves the valve member between a first position (e.g., opened/closed position) and a second position (e.g., closed/opened position), and a return device operably connected to the valve member. The return device is in a mechanically relaxed condition when the valve member is in the first position and a biased condition when the valve member is the second position. If the motor's electrical power is lost and the valve member is in the second position, the return member mechanically returns the valve member to the first position.

DETAILED DESCRIPTION

Referring now to the drawings, and initially toFIG. 1, an aircraft10including a water supply system12is shown inFIG. 1. The system12provides potable water to respective outlets of various water-using devices14(e.g., sink faucets, coffee brewers, toilets, etc.) onboard the aircraft10.

Referring additionally toFIG. 2, the aircraft water supply system12is schematically shown in more detail. The system12can comprise a tank16and a series of plumbing lines18for supplying the outlets14, filling the tank16, draining the tank16, and/or venting the tank16. For example, in the illustrated embodiment, the system12comprises outlet-supply lines18a, a fill-drain line18b, a tank-overflow (and/or tank-ventilation) line18c, a fill line18d(for pre-flight connection to an external water source), and a drain line18e(for post-flight connection to an external sewer).

The system12can further comprise one or more valve assemblies20in the plumbing lines18for opening/closing for these lines for pre-flight, post-flight, and in-flight purposes. For example, a tank-isolation valve assembly20acan be positioned in the tank's fill-drain line18b; a tank-venting valve assembly20bcan be positioned in the tank-overflow line18c, a tank-fill valve20ccan be positioned in the fill line18d, and a drain-plug valve20dcan be positioned in the drain line18e.

To fill the tank16(e.g., during preflight procedures), the valve assembly20a, the valve assembly20b, and the valve assembly20cwould each be in an opened condition. The valve assembly20dwould be in a closed condition. Water from an external source would be pumped through the fill line18d, through the tank's line18b, and into the tank16. Air within the tank16would be vented through the line18c.

To drain the tank16(e.g., during post-flight procedures), the valve assembly20aand the valve assembly20dwould each be in an opened condition. The valve assembly20cwould be in an closed condition. Water would be drained from the tank16through line18bto line18eand into an external sewer.

During normal flight operation, the valve assembly20aand the valve assembly20cwould each remain in a closed condition. The valve assembly20band the valve assembly20dcould remain in an opened condition to allow emergency overflow drain from the tank16.

Turning now toFIG. 3, the valve assembly20is shown isolated from the rest of the water supply system12. The valve assembly20comprises a valve device30, an electrical motor device32, and a return device34. The valve device30includes a valve member40movable by the electrical motor device32between a first position and a second position. The first position can be an opened position and the second position can be a closed position (corresponding to the valve assembly20being in an opened condition and closed condition, respectively). Or the first position can be closed position and the second position can be the opened position.

One of the first position or second position can be a predetermined preferred position in the event of a power loss. In some constructions and/or circumstances, the preferred position will be the opened position, while in others it will be the closed position. If an analogy is made to a solenoid-style valve, this predetermined preferred position would correspond to the normally-opened or normally-closed design of the solenoid. In any event, for ease in explanation, the first position can be considered the preferred power-loss position.

The return device34is operably connected to the valve member40. The return device34is in a mechanically relaxed condition when the valve member40is in the first position and is in a mechanically biased condition when the valve member40is the second position. Thus, if a power loss occurs when the valve member40is in the second position, the return device34can automatically (and non-electrically) return the valve member40to the first position.

The valve device30includes (in addition to the valve member40), a valve body42defining input-output connectors44and a chamber46therebetween. In the water supply system12, for example, the connectors44would be joined to segments of the relevant plumbing line18. When the valve assembly20is in its opened condition (i.e., the valve member40is in its opened position), a fluid flow path is formed from one connector44through the chamber46and to the other connector44. Heating coils (shown but not specifically numbered) can be installed in the connectors44to prevent freezing within the chamber46.

The valve device30and/or the valve body42can further comprise a motor-mounting plate48and a return-mounting plate50. The mounting plates48and50can be bolted or otherwise fixedly attached to the motor device32and the return device34, respectively. The valve member40is movably mounted relative to the valve body42(and/or the mounting plates48/50). Suitable seals (some shown, but not specifically numbered) can be situated between the various valve parts and/or between valve-interfacing parts of the devices32and34.

The valve member40can comprise a fluid-interacting portion52positioned within the chamber46. The portion52can have a generally spherical shape (i.e., a ball) with a diametric fluid passageway54therethrough. When the valve member40is in its closed position (as illustrated), the chamber46is sealed from the fluid connectors44by the solid surfaces of the ball portion52. The passageway54does not communicate with the fluid in the line18. When the valve member42is moved (e.g., rotated 90°) to its opened position, the passageway54forms a flow path through the chamber46.

The valve member40can comprise a crown56extending radially (e.g., upwardly) from the ball portion52. The crown56protrudes from the valve body42(and the chamber46) and is operably connected to movement-providing members (e.g., gears66introduced below) of the electric motor device32.

The valve member40can also (or alternatively) comprise a stem58extending radially (e.g., downwardly) from its ball portion52. The stem58also protrudes from the valve body42(and the chamber46) and extends into the return device34. A guide60within the return device34can interact with the stem58during rotation of the valve member40. In the illustrated embodiment, the stem58has an internally threaded bore and the stem guide60has an externally threaded rod received within this bore.

The valve member40can further comprise a return-drive pin62that interacts with the return device34. In the illustrated embodiment, the return-drive pin62extends transversely through and beyond the stem58.

The motor device32can comprise an electrical motor64that produces rotational motion, gears66that transfer this motion to the valve member40via the crown56, and an electrical brake68. In the illustrated embodiment, when power is applied, the motor64and gears66drive the valve member40from the closed position to the open position. That is, they turn the ball portion52approximately 90° within the chamber46. At the completion of the turn, the brake68can be activated to hold the position, thereby significantly reducing power draw. If the brake68is installed on the motor-side of the gear box (as shown), the gears66will assist in holding the valve position.

The motor components64,66and68can be enclosed in a housing70mounted (e.g., via brackets72) to convenient location in the aircraft10. The housing70can be attached to the valve's mounting plate48or otherwise fixed or mounted to the valve body42. Electrical power/control lines can extend to the motor64and/or brake68through a socket opening74in the housing70.

The return device34comprises a returning mechanism80that is operably connected to the valve member40and rotates therewith during electrical operation of the valve assembly20. The mechanism80can be in a mechanically relaxed condition when the valve member40is in the first position, and in a biased condition when the valve member is in the second position. In any event, when the valve member40is in the second position, the returning mechanism80biases it towards the first position. If the valve member40is in the second position, and the motor device32loses electrical power, the mechanism80non-electrically (e.g., mechanically) returns the valve member40to the first position.

The returning mechanism80can comprise a spring82that is wound, or biased, when the valve member40moves from the first position to the second position. In the illustrated embodiment, the mechanism80includes a torque tube84that winds the spring82during such valve movement. More specifically, the torque tube84interacts with the return-drive pin62which turns with the stem58when the valve member40is moved from the first position to the second position.

One end of the spring82(e.g., its top end) can be connected to a cap86. (FIG. 6.) The cap86can be fixedly mounted to the valve body42(and/or mounting plate50) via bolts88or other attachment means. A casing can surround the returning mechanism80and the cap86can be secured thereto.

The other end of the spring82(e.g., its bottom end) can be connected to the torque member84. (FIG. 7.) Thus, the top end of the spring82remains stationary (with the cap86) and the bottom end of the spring82moves with the torque tube84. In this manner, the spring82will be “wound” when the valve member40moves from the first position to the second position, and “unwound” when the valve member40moves from the second position to the first position.

A valve-interacting portion of the torque member84(e.g., it top portion) includes engaging ledges90. (FIG. 6.) During electrical operation, the drive pin62engages the ledges90and pushes them as the valve member40moves from the first position to the second position. (FIG. 8.) When the ledges90reach the second position, they encounter the stop pins92fixedly mounted to the cap86. In the event of electrical loss, the ledges90will be spring biased back to the first position, thereby also pushing return-drive pin62(and thus the valve member40) back to the first position. When the ledges90reach the first position, they encounter the stop pins92.

The valve assembly20can be adapted for manual operation when electrical power is not being provided. Specifically, for example, the valve member40can be turned by a handle or other suitable tool in the appropriate direction (e.g., clockwise inFIG. 8) until the drive pin62is stopped by the ledges90. This manual rotation will also drive the motor64and the gears66. A manually-set valve assembly20will resume to normal operation when power is applied and the valve member40is placed in its electrically commanded position.

One may now appreciate that the valve assembly20allows a ball-valve construction with a solenoid-style return to a predetermined position in the event of a power loss. For these and other reasons, the valve assembly20can find special application in aircraft situations where solenoid-gate construction are undesirable but a loss-of-power contingency plan is necessary. Although the aircraft10, the aircraft water supply system12, the valve assembly20, and the various component thereof have been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In regard to the various functions performed by the above described elements (e.g., components, assemblies, systems, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function. In addition, while a particular feature may have been described above with respect to only one or more of several illustrated embodiments, such a feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.