Patent Description:
The present disclosure relates generally to inflatable fluid sources and, more particularly, to a valve arrangement for a pressurized fluid source of an evacuation assembly.

Inflatable evacuation systems may be found on various structures, including aircraft, boats, offshore drilling platforms and the like. The systems are typically equipped with an inflatable or an inflatable device, such as, for example, an inflatable slide or an inflatable raft, configured to facilitate rapid evacuation of persons in the event of an emergency. Such inflatables are typically stored in an uninflated condition on the structure in a location readily accessible for deployment. For example, an evacuation slide for a commercial aircraft is stored in an uninflated condition in a case or compartment located proximate an emergency exit. <CIT> relates to a proportional flow control valve poppet with flow control needle.

Systems used to inflate evacuation slides typically employ a gas stored within a cylinder or tank at high pressure, which is discharged into the evacuation slide (or into an inflatable tube comprised within the evacuation slide) within a specific time period. This may be accomplished, for example, by opening a main inflation valve that connects the high-pressure gas to the inflatable tube.

A valve arrangement for a pressurized fluid source according to claim <NUM> is disclosed.

In various embodiments, the regulating valve poppet comprises a shaft and a plug.

In various embodiments, the valve arrangement further comprises a valve seat land, wherein a valve face of the plug is configured to abut the valve seat land when the regulating valve poppet is in a closed position, and the inlet is sealed from the outlet in response to the regulating valve poppet moving to the closed position.

In various embodiments, the valve arrangement further comprises a spring abutting the plug, wherein the spring biases the plug towards the valve seat land. In various embodiments, the valve arrangement further comprises a dynamic O-ring seal configured to fluidically isolate the linear stepper motor from the main fluid channel.

In various embodiments, the linear stepper motor is operated with the controller.

In various embodiments, the valve arrangement further comprises a temperature sensor, wherein the controller is configured to receive a temperature feedback signal and the controller is configured to control the linear stepper motor based upon the temperature feedback signal.

In various embodiments, the valve arrangement further comprises a power source for powering the linear stepper motor.

In various embodiments, the controller is configured to vary a stroke speed of the regulating valve poppet based upon the temperature feedback signal.

In various embodiments, the controller is configured to vary a stroke position of the regulating valve poppet based upon the pressure feedback signal.

In various embodiments, the outlet is fluidly disconnected from the inlet when the regulating valve poppet is in a closed position. The outlet is fluidly connected with the inlet when the regulating valve poppet is in an open position.

In various embodiments, the main fluid channel fluidly connects the inlet and the outlet.

In various embodiments, the valve arrangement further comprises a temperature sensor, wherein a controller is configured to receive a temperature feedback signal from the temperature sensor and the controller is configured to control the linear stepper motor based upon the temperature feedback signal.

In various embodiments, the valve arrangement further comprises a spring configured to bias the regulating valve poppet toward the closed position.

An evacuation assembly is disclosed, comprising a pressurized fluid source and a valve assembly configured to control a flow of pressurized fluid from the pressurized fluid source. The valve assembly is a valve assembly according to claim <NUM>.

In various embodiments, the evacuation assembly further comprises a temperature sensor, wherein an operating speed of the linear stepper motor is variable based upon a temperature feedback signal received from the temperature sensor, and a pressure sensor, wherein a position of the linear stepper motor is variable based upon a pressure feedback signal received from the pressure sensor.

In various embodiments, the evacuation assembly further comprises an evacuation slide fluidly coupled to the valve outlet.

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the exemplary embodiments of the disclosure, it should be understood that other embodiments may be realized in accordance with this disclosure and within the scope of the claims. Thus, the detailed description herein is presented for purposes of illustration only and not limitation.

Surface lines may be used throughout the figures to denote different parts but not necessarily to denote the same or different materials. Throughout the present disclosure, like reference numbers denote like elements. Accordingly, elements with like element numbering may be shown in the figures, but may not necessarily be repeated herein for the sake of clarity.

The systems and methods disclosed herein may find particular use in connection with aircraft evacuation assemblies. However, various aspects of the disclosed systems and methods may be adapted for performance in a variety of other inflatable assemblies, for example, inflatable raft assemblies, and/or any other assemblies having charged cylinders. As such, numerous applications of the present disclosure may be realized.

Conventional pressure regulator units are typically acceptance tested for desired pressure characteristics over time using a pressurized gas bottle, aspirators, and feed hoses. Flow performance is typically achieved by the shaping of a poppet control profile and its positioning within a control orifice. The shaped profile of the poppet in conjunction with body orifice constitutes the flow area which is variable with poppet travel. The positioning of the poppet or the poppet travel is influenced by the applicable force balancing between a spring and fluid pressure forces. Initially at the start of inflation, the bottle pressure force is higher and the poppet stroke is less. Because of higher bottle pressure, sufficient flow outage at higher pressures are maintained at the regulator outlet. As the inflation progress, the bottle pressure reduces with time and the poppet stroke increases in passive mode. This stroke increase tends not to be enough to maintain same level of outlet pressure achieved during the initial phase. Thus, the flow outlet pressure reduces over time with inflation. Accordingly, the inflation build up rate decreases and the time duration to achieve the desired inflation increases.

This regulator performance varies with operating temperatures, as shown in <FIG>. The outlet pressure values increase with operating temperatures and decrease at lower temperatures. Because conventional pressure regulators typically operate in self-acting passive mode, no active corrections are possible to compensate for these performance variations. Some level of design-driven partial correction may be possible as the force balancing varies with fluid pressures influenced by the operating temperatures. Thus, at lower operating temperatures this regulator opening area tends to increase and decrease at higher temperatures. Accordingly, inflation will be faster at elevated temperatures and be slower at lower temperatures.

A pressure reducing regulator of the present disclosure is designed to eliminate the above performance drawbacks of conventional pressure regulators and to improve the inflation system performance. Using a pressure reducing regulator of the present disclosure, similar outlet pressure values can be achieved throughout the inflation time and this would reduce the inflation time further. Moreover, regulator performance variation with temperature can be eliminated with a pressure reducing regulator of the present disclosure. A pressure reducing regulator of the present disclosure can be integrated with flow shut off functions with good leak tightness. A pressure reducing regulator of the present disclosure may eliminate the need for a separate isolation or shut off valve.

A pressure reducing regulator of the present disclosure utilizes closed loop pressure controls with a DC linear stepper motor operated pressure control valve. This electrically operated valve is designed with flow shut off and pressure reducing regulating features. Thus, no separate flow shut off may be necessary. A pressure reducing regulator of the present disclosure may be operated repeatedly in component and system level and no re-setting (e.g., such as tends to be necessary in conventional manual operating regulator units) is necessary.

Because it is possible to increase the regulator flow area actively with a pressure reducing regulator of the present disclosure, the outlet flow rate may be increased to achieve higher pressures during inflation. For a specified gas bottle pressure, almost steady uniform regulator pressure values are maintained during inflation with a pressure reducing regulator of the present disclosure. By this, the inflatable inflation time can be reduced and the overall evacuation time can be reduced from existing systems.

In various embodiments, regulator performance variation with ambient temperatures may be reduced and/or eliminated by utilizing a pressure reducing regulator of the present disclosure. Different regulated pressure profiles may be easily achieved by varying the conical poppet profile. In various embodiments, a standard off the shelf linear stepper motor may be used with a pressure reducing regulator of the present disclosure. The motor output is linear movement and the position can be adjusted by controlling the number of DC voltage pulses. The speed of the linear movement can be controlled by varying the frequency of the DC voltage pulses supplied to the motor. A stepper motor may simplify the design as it may not require any position control feedback and related servo control schemes, such as those utilized by conventional pressure regulating servo valves. The actuation load requirement may be minimized by utilizing the pressure balancing features possible due to O-ring dynamic seals provided in a pressure reducing regulator of the present disclosure.

A pressure reducing regulator of the present disclosure is electrically operated with intelligence added operational features. A pressure reducing regulator of the present disclosure may have repeated on/off operational features. Thus, a pressure reducing regulator of the present disclosure may be used for the inflatable application to stop excess gas from flowing after inflated to the desired pressure.

Being a pressure reducing regulator, temperature of the fluid reduces due to gas expansion at higher pressure drops and fluid freezing may tend to occur inside the regulator, in various embodiments. Because this design uses electrically driven devices with a controller, heating elements may be more easily implemented to heat the pressure reducing regulator to avoid ice from forming. A pressure reducing regulator of the present disclosure may be used across various platforms.

Referring now to <FIG>, an aircraft <NUM> is shown. Aircraft <NUM> may include a fuselage <NUM> having plurality of exit doors, including exit door <NUM>. Aircraft <NUM> may include one or more evacuation assemblies positioned near a corresponding exit door. For example, aircraft <NUM> includes an evacuation assembly <NUM> positioned near exit door <NUM>. In the event of an emergency, exit door <NUM> may be opened by a passenger or crew member of aircraft <NUM>. In various embodiments, evacuation assembly <NUM> may deploy in response to exit door <NUM> being opened or in response to another action taken by a passenger or crew member, such as the depression of a button, the actuation of a lever, or the like.

With reference to <FIG>, additional details of evacuation assembly <NUM> are illustrated. In accordance with various embodiments, evacuation assembly <NUM> includes an evacuation slide <NUM> and a pressurized fluid source <NUM>. In accordance with various embodiments, evacuation slide <NUM> includes a toe end <NUM> and a head end <NUM> opposite toe end <NUM>. Head end <NUM> may be coupled to an aircraft structure (e.g., fuselage <NUM> in <FIG>). In accordance with various embodiments, evacuation slide <NUM> is an inflatable slide. Evacuation slide <NUM> includes a sliding surface <NUM> and an underside surface <NUM> opposite sliding surface <NUM>. Sliding surface <NUM> extends from head end <NUM> to toe end <NUM>. During an evacuation event, underside surface <NUM> may be oriented toward an exit surface (e.g., toward the ground or toward a body of water). Evacuation slide <NUM> is illustrated as a single lane slide; however, evacuation slide <NUM> may comprise any number of lanes.

Evacuation assembly <NUM> includes pressurized fluid source <NUM> (also referred to as a charge cylinder). Pressurized fluid source <NUM> is configured to deliver a pressurized fluid, such as pressurized gas, to inflate evacuation slide <NUM>. Pressurized fluid source <NUM> is fluidly coupled to evacuation slide <NUM>. For example, pressurized fluid source <NUM> may be fluidly coupled to evacuation slide <NUM> via a hose, or conduit, <NUM>. In response to receiving pressurized fluid from pressurized fluid source <NUM>, evacuation slide <NUM> begins to inflate.

In accordance with various embodiments, conduit <NUM> may be connected to a valve outlet <NUM> of a valve assembly <NUM> (also referred to herein as a pressure regulator shutoff valve or a pressure reducing regulator) fluidly coupled to pressurized fluid source <NUM>. In this regard, valve assembly <NUM> is fluidly coupled between pressurized fluid source <NUM> and conduit <NUM>. As described in further detail below valve assembly <NUM> is configured to regulate the flow of pressurized fluid from pressurized fluid source <NUM> to evacuation slide <NUM>. In this regard, when evacuation slide <NUM> is in a stowed (or deflated) state, valve assembly <NUM> is in a closed position. In response to deployment of evacuation assembly <NUM>, valve assembly <NUM> may move or translate to an open position, thereby allowing fluid to flow from pressurized fluid source <NUM> to evacuation slide <NUM>.

With reference to <FIG>, additional details of valve assembly <NUM> are schematically illustrated, in accordance with the claimed invention. In various embodiments, valve assembly <NUM> includes a valve housing <NUM> (sometime referred to as a valve manifold). Valve housing <NUM> extends along longitudinal axis <NUM>. Valve housing <NUM> may be additively manufactured. Valve housing <NUM> may be manufactured using conventional machining methods. For example, the internally provided flow passages may be drilled from the extreme side faces and the relevant openings plugged afterwards.

Valve housing <NUM> defines valve outlet <NUM> and a valve inlet <NUM> of valve assembly <NUM>. Valve assembly <NUM> receives fluid from pressurized fluid source <NUM> through valve inlet <NUM>. Other components of pressurized fluid source <NUM> may also be coupled to valve housing <NUM>. For example, in various embodiments, a pressure gauge, configured to measure a pressure of pressurized fluid source <NUM>, may be operatively coupled to pressurized fluid source <NUM> via valve assembly <NUM>. In various embodiments, a shutoff valve may be operatively coupled to pressurized fluid source <NUM> via valve assembly <NUM>.

Valve housing <NUM> may further define a main fluid channel <NUM> through valve housing <NUM>. The main fluid channel <NUM> is coaxial with longitudinal axis <NUM>. Main fluid channel <NUM> may be fluidly connected with valve inlet <NUM> and valve outlet <NUM>.

A regulating valve poppet <NUM> is located in main fluid channel <NUM>. In the open position (see <FIG>), valve poppet <NUM> regulates the flow of pressurized fluid from pressurized fluid source <NUM> to valve outlet <NUM>. In the open position, a spring <NUM> may bias the valve poppet <NUM> along longitudinal axis <NUM> in a first direction (i.e., to the right in <FIG>). After valve poppet <NUM> has moved to the closed position (see <FIG>), spring <NUM> may aid in securing valve poppet <NUM> in the closed position to prevent leakage between valve face <NUM> and valve seat land <NUM>. Valve seat land <NUM> may at least partially define main fluid channel <NUM>. In various embodiments, valve seat land <NUM> is round or oval in cross-section. Valve poppet <NUM> may comprise a plug <NUM> extending from a shaft <NUM> (also referred to as a valve stem). Plug <NUM> may comprise a disc shape. The working end of this plug <NUM>, the valve face <NUM>, may be oriented at an angle (e.g., a <NUM>° (or other suitable angle) bevel) with respect to longitudinal axis <NUM> to seal against the corresponding valve seat land <NUM> formed into a rim of the main fluid chamber <NUM> being sealed. Shaft <NUM> may travel through a valve guide <NUM> to maintain its alignment. Valve guide <NUM> may comprise a bore configured to receive shaft <NUM>.

Valve assembly <NUM> comprises a closed loop pressure control system including a control unit <NUM>, one or more feedback sensors (e.g., temperature sensor <NUM> and/or pressure sensor <NUM>) including at least one pressure sensor <NUM>, and a linear stepper motor <NUM>. In various embodiments, control unit <NUM> may be preset with desired outlet pressure vs time values with which linear stepper motor <NUM> is controlled.

In various embodiments, control unit <NUM> includes one or more controllers (e.g., processors) and may include one or more tangible, non-transitory memories capable of implementing digital or programmatic logic. In various embodiments, for example, the one or more controllers are one or more of a general purpose processor, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA), or other programmable logic device, discrete gate, transistor logic, or discrete hardware components, or any various combinations thereof or the like. In various embodiments, the control unit <NUM> controls, at least various parts of, and operation of various components of, the valve assembly <NUM>. For example, the control unit <NUM> controls linear stepper motor <NUM>.

Shaft <NUM> may be configured to translate along longitudinal axis <NUM> with the aid of a linear stepper motor <NUM>. Linear stepper motor <NUM> may be mounted to valve housing <NUM>. Linear stepper motor <NUM> may convert rotary movement (e.g., of a rotor) into linear movement (e.g., of shaft <NUM>) in a known manner. Linear stepper motor <NUM> may be coupled to shaft <NUM>. In various embodiments, shaft <NUM> is directly attached to linear stepper motor <NUM>. Linear stepper motor <NUM> may be operated to translate shaft <NUM> along longitudinal axis <NUM> to increase and/or decrease a flow volume between valve face <NUM> and valve seat land <NUM> to regulate the flow of compressed fluid through valve housing <NUM> to maintain a desired outlet pressure.

A dynamic O-ring seal <NUM> may be provided to reduce the potential for the fluid medium contacting the electric motor of linear stepper motor <NUM>. Seal <NUM> may be provided around shaft <NUM>. Seal <NUM> may be disposed between valve housing <NUM> and shaft <NUM>. In this regard, seal <NUM> may fluidically isolate the stepper motor <NUM> from the main fluid channel <NUM>. In various embodiments, a fluid pressure force acting on seal <NUM> provides a closing force to valve poppet <NUM>, which may ensure adequate leak tightness.

Control unit <NUM> may be provided to control the position of linear stepper motor <NUM> and thus the position of regulating valve poppet <NUM> with respect to valve seat land <NUM>. Control unit <NUM> receives pressure feedback and may receive temperature feedback (e.g., from temperature sensor <NUM> and/or pressure sensor <NUM>) to control linear stepper motor <NUM>. To increase a flow rate of compressed fluid through valve assembly <NUM>, control unit <NUM> may cause valve poppet <NUM> to translate along longitudinal axis <NUM> in a second direction (i.e., to the left in <FIG>) to increase or open the gap between valve poppet <NUM> and valve seat land <NUM>. To decrease a flow rate of compressed fluid through valve assembly <NUM>, control unit <NUM> may cause valve poppet <NUM> to translate along longitudinal axis <NUM> in a first direction (i.e., to the right in <FIG>) to decrease or close the gap between valve poppet <NUM> and valve seat land <NUM>.

With reference to <FIG>, in the fully closed position, the conical poppet valve face <NUM> interfaces with valve seat land <NUM> of the control orifice body (i.e., housing <NUM>). The desired closing force to ensure good leak tightness can be provided by maintaining appropriate force balancing. This may involve selection of appropriate spring <NUM> force, dynamic O-ring seal <NUM> size, and the conical poppet sealing area. Fluid leak tightness in the shut off position can be achieved by providing adequate sealing stress influenced by this net closing force, the seating land area, and the surface finishes of the seal and seat interfacing faces. Leak tightness can be improved further using a seat land bushing made of plastic material. In this manner, a separate flow shut off or isolation valve may not be necessary.

From the initial shut off position, when the stepper motor <NUM> is energized (e.g., with DC voltage pulses), it may develop electro mechanical force to actuate the valve poppet <NUM> in the opening direction (i.e., toward the left in <FIG>) and flow area may be established (see <FIG>). With reference to <FIG>, this flow area may replicate a conical frustum. This flow area (A) around the conical poppet profile region increases with valve stroke (x). Linear stepper motor <NUM> can be made to drive the valve poppet <NUM> in the closing direction (i.e., to the right in <FIG>) also by changing the electric polarity. For a given valve body orifice diameter, the flow area change with poppet movement (dA/dx) may be influenced by the shaping of conical poppet profile only. Linear stepper motor <NUM> operation may involve the application of DC voltage pulses. The number of DC voltage pulses per unit time feeding to the motor may determine the motor operating speed. This may directly control the valve poppet <NUM> stroke change with time (t). Thus, the resultant flow area change with time may be influenced by the profile design and the regulator valve operating speed.

As illustrated, the valve outlet pressure is monitored by a pressure sensor <NUM> with feedback to the control unit <NUM>. Control unit <NUM> may be pre-set with the desired outlet pressure values with an inflation time profile. Once the linear stepper motor <NUM> is energized to open valve poppet <NUM>, if the outlet pressure measured is higher than the pre-set value, control unit <NUM> may generate a control command to linear stepper motor <NUM> actuating the valve poppet <NUM> to reduce the flow area by moving the valve poppet <NUM> in a closing direction. Conversely, if the pressure measured is less than pre-set value, then the pressure may be corrected by increasing the flow area. Control unit <NUM> may stop generating control command once the feed value matches with the preset value. Suitable algorithm(s) can be developed for processing of this pressure control or regulation taking the desired operational features. The control unit <NUM> can be embedded with processing software to achieve the desired pressures at the regulator outlet.

With reference to <FIG>, a chart illustrating regulator valve stroke versus inflation time for various temperatures is illustrated, in accordance with various embodiments. At lower temperatures, it may be desirable to increase the valve stroke or the opening area to achieve the same inflation time profile as for higher temperatures. Conversely, at higher temperatures, it may be desirable to reduce the valve stroke or decrease the opening area to achieve the same inflation time profile as for lower temperatures. Within the same time interval, these stroke vs time profiles can be achieved by varying the operating speed of linear stepper motor <NUM>. For linear stepper motor <NUM>, this may be achieved by varying the feed rate of input DC voltage pulses per second (pps). Higher pps may increase the speed and vice versa. The valve operating speed may be increased at higher temperatures and decreased at lower temperatures to achieve a desired inflation time. Stated differently, the rate or speed at which valve poppet <NUM> is translated toward a fully open position over inflation time may be increased at lower temperatures. Conversely, the rate or speed at which valve poppet <NUM> is translated toward a fully open position over inflation time may be decreased at higher temperatures. In this manner, with momentary reference to <FIG>, control unit <NUM> may receive temperature feedback from temperature sensor <NUM> and may vary the valve stroke speed based upon this temperature feedback. Temperature sensor <NUM> may measure the temperature of fluid flowing through (and/or out of) valve assembly <NUM>.

A power source <NUM> may be provided for powering valve assembly <NUM>. Power source <NUM> may power linear stepper motor <NUM>. Power source <NUM> may power control unit <NUM>. Power source <NUM> may power temperature sensor <NUM>. Power source <NUM> may power pressure sensor <NUM>. Power source <NUM> may be a battery, a super capacitor, and/or any other suitable power source.

With combined reference to <FIG>, a valve assembly <NUM> is illustrated in an open position and closed position, respectively, not in accordance with the claimed invention. Valve assembly <NUM> may be similar to valve assembly <NUM>, except that the flow force of valve assembly <NUM> acts in the valve closing direction, whereas in <FIG>, the flow forces are acting in the valve opening direction. The linear stepper motor <NUM> actuation force may be determined by the resistance force to operate the regulator valve in both the open and closing directions. The regulator valve designs discussed herein with respect to <FIG> and <FIG> may be analyzed for resistance force parameters to determine optimal regulator design. A motor with a higher margin on resistance torque may provide higher operating speed and/or faster response time.

In various embodiments, valve assembly <NUM> generally includes valve housing <NUM>, valve poppet <NUM>, and linear stepper motor <NUM>. Valve assembly <NUM> may further include spring <NUM>. Spring <NUM> may bias valve poppet <NUM> toward a closed position (see <FIG>). A dynamic O-ring seal <NUM> may be provided to avoid the fluid medium from contacting the electric motor of linear stepper motor <NUM>. Seal <NUM> may be disposed between valve housing <NUM> and valve poppet <NUM>. The closed loop pressure control system of valve assembly <NUM> is omitted for simplicity of illustration. However, it should be understood that valve assembly <NUM> may further include a control system similar to that of valve assembly <NUM> as illustrated in <FIG>.

Claim 1:
A valve arrangement for a pressurized fluid source, the valve arrangement comprising:
a valve housing (<NUM>) comprising an inlet (<NUM>), an outlet (<NUM>), and a main fluid channel (<NUM>) extending along a longitudinal axis of the valve housing;
a regulating valve poppet (<NUM>) located in the main fluid channel (<NUM>), the regulating valve poppet configured to translate along the longitudinal axis of the valve housing;
a linear stepper motor (<NUM>) configured to control a position of the regulating valve poppet (<NUM>);
a pressure sensor (<NUM>) located between the regulating valve poppet (<NUM>) and the outlet to monitor the valve outlet pressure; and
a controller, wherein the controller is configured to receive a pressure feedback signal from the pressure sensor (<NUM>), and to control the linear stepper motor (<NUM>) based upon the pressure feedback signal to maintain a substantially constant output pressure of the pressurized fluid source (<NUM>).