BACKGROUND

Technical Field

The present disclosure pertains to the controlled release of pressurized gas and, more particularly, to a lightweight electrically-actuated valve suitable for aerial vehicles that enables an in-flight rapid release of a pressurized fluid for the deployment of a decelerator system.

Description of the Related Art

The field of aerial vehicles, including Unmanned Aerial Vehicles or UAVs, is growing and continues to develop for both military and civilian applications. A UAV is generally considered to be a "powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry a lethal or nonlethal payload." (See https://en.wikipedia.org/wiki/Unmanned_aerial_vehicle.)

UAVs have application in military uses such as reconnaissance, attack, defense against other UAVs, and targets for training, such as for criminal and terrorist attacks. They are also used in civil applications, including hobby and recreational use, commercial aerial surveillance, professional aerial surveying, commercial and motion picture filmmaking, journalism, law enforcement, search and rescue, scientific research, pollution monitoring, oil, gas and mineral exploration and production, disaster relief, archaeology, transport, agriculture, and much more.

Due to the multitude of uses and varying altitudes at which UAVs are flown, people and structures in the surrounding area are at risk for severe damage when the UAV fails and control is lost. UAVs are not built to the same standards as manned aerial vehicles, and frequently fail. In addition, government regulation of UAV construction and piloting is increasing, particularly with respect to the use of safety devices. Therefore, it is necessary to utilize some means to arrest an uncontrolled descent of a UAV. Current proposals include the use of non-inflatable or spring-loaded aerodynamic decelerator launch system, such as a parachute, to protect the people and structures in the surrounding area during a failure. However, parachute systems present an entirely new set of issues, including failure to deploy properly, and entanglement of the parachute lines in the propellers and control surfaces of the UAV due to improper deployment. Hence, there is a need for inflatable deployment techniques that ensure rapid and tangle-free opening of the parachute.

BRIEF SUMMARY

The present disclosure is directed to an apparatus for use in deploying a decelerator for resisting or arresting uncontrolled descent of an aerial vehicle. More particularly, the present disclosure apparatus addresses unmanned single and multi-rotor aerial vehicles, but has a purpose in other lightweight manned vehicles.

In accordance with one aspect of the disclosure, a solid state (no moving mechanical parts) design is provided in which a rapid escape of pressurized fluid is provided through controlled rupture of a membrane positioned between the pressurized gas and the intended application, such as a deployment apparatus. In one implementation, the membrane is formed of a material that is breeched by a controlled application of heat.

In accordance with another aspect of the present disclosure, a solid state valve for use with high pressure fluid in an aerial vehicle is provided, the valve including a valve body with an opening to permit the high pressure fluid to pass through the opening and out of the valve body, a membrane positioned over the opening in the valve body to retain the high pressure fluid in the valve body, and a wire on the membrane that is capable of burning the membrane in response to application of electricity to the wire, and thereby release the pressurized fluid from the opening in the valve body.

In accordance with yet another aspect of the present disclosure, a solid state valve is provided that includes a valve body, a membrane, preferably in the form of a wafer or layer of fibrous material, and wire on the fibrous material, preferably a loop of exposed Nichrome wire, and a cover. In one implementation, multiple layers of silicone membranes and fasteners ae provided. Application of electricity to the loop of wire causes selective failure of the membrane (or fibrous material) that results in a rapid release of a large amount of pressurized gas.

In accordance with a further aspect of the present disclosure, a valve assembly for use with an aerial vehicle is provided. The assembly includes a valve body having an internal axial bore, an intake port, and an exit port, the intake port and the exit port in fluid communication with the bore, the body having a substantially planar top face with an opening in the exit port. It further includes an O-ring capable of being positioned on the top face and sized and shaped to encircle the exit port opening, a first layer of self-healing silicone material capable of being placed over the O-ring and in contact with the valve body face, the first layer of silicone material having an opening formed therein with a diameter that is sized slightly smaller than, and shaped to align with, the exit port opening to permit the passage of gas through the first layer of silicone, a layer of fibrous material capable of being placed over the first layer of silicone material and in contact with the valve body face, and a loop of exposed wire (preferably Ni chrome) having first and second ends, the loop of exposed wire sized and shaped to have a diameter slightly larger than the diameter of the O-ring, the loop of exposed wire capable of being positioned on top of the layer of fibrous material and in alignment with the opening in the first layer of silicone material below the layer of fibrous material, with the first and second ends of the loop of exposed wire extending beyond the valve body. In addition, it includes a second layer of self-healing silicone material capable of being placed over the loop of exposed wire and in contact with the layer of fibrous material, the second layer of silicone material having an opening formed therein with a diameter that is sized slightly smaller than the loop of exposed wire and shaped to align with the loop of exposed wire, the opening in the first layer of silicone material, and the exit port opening to permit the passage of gas through the second layer of silicone material, a washer of silicone with a central opening having a diameter greater than the diameter of the opening in the second layer of silicone material, the washer sized and shaped to be placed over the second layer of silicone material without extending beyond the layer of fibrous material, and a cover sized and shaped to be placed over the top face of the valve body and capable of being held in place with fasteners to secure the first and second layers of silicone material, the layer of fibrous material, the loop of wire, and the washer in concentric alignment.

In accordance with yet a further aspect of the present disclosure, a system to deploy a parachute on an aerial vehicle is provided. The system includes a tank capable of storing pressurized gas; a parachute storage device; and a pneumatic valve assembly capable of coupling to the pressurized gas tank and the parachute storage device. The pneumatic valve assembly includes a valve body having an internal axial bore, an intake port, and an exit port, the intake port and the exit port in fluid communication with the bore, the body having a substantially planar top face with an opening in the and partially defining the exit port. It further includes an O-ring capable of being positioned on the top face and sized and shaped to encircle the exit port opening, a first layer of self-healing silicone material capable of being placed over the O-ring and in contact with the valve body face, the first layer of silicone material having an opening formed therein with a diameter that is sized slightly smaller than, and shaped to align with, the exit port opening to permit the passage of gas through the first layer of silicone, a layer of fibrous material capable of being placed over the first layer of silicone material and in contact with the valve body face, and a loop of exposed wire having first and second ends, the loop of exposed wire sized and shaped to have a diameter about the same as the diameter of the opening in the first layer of silicone material, the loop of exposed wire capable of being positioned on top of the layer of fibrous material and in alignment with the opening in the first layer of silicone material below the layer of fibrous material, with the first and second ends of the loop of exposed wire extending beyond the valve body. In addition, it includes a second layer of self-healing silicone material capable of being placed over the loop of exposed wire and in contact with the layer of fibrous material, the second layer of silicone material having an opening formed therein with a diameter that is sized slightly smaller than and shaped to align with the loop of exposed wire, the opening in the first layer of silicone material, and the exit port opening to permit the passage of gas through the second layer of silicone material, a washer of silicone with a central opening having a diameter greater than the diameter of the opening in the second layer of silicone material, the washer sized and shaped to be placed over the second layer of silicone material without extending beyond the layer of fibrous material, and a cover sized and shaped to be placed over the top face of the valve body and capable of being held in place with fasteners to secure the first and second layers of silicone material, the layer of fibrous material, the loop of wire, and the washer in concentric alignment.

As will be appreciated from the foregoing, the solid state design of the device avoids issues created by using moving parts, which has simplicity of design allowing for less room for failure of parts. The device is not mechanically actuated and therefore not susceptible to environmental conditions and potential flight situations. The device must be mechanically fastened to a pressure vessel. When triggered, the device allows compressible fluid to travel from the pressure vessel, through the device, and to the deployment apparatus, therefore causing the inflatable structure to inflate rapidly to a rigid state, moving the actual opening of the aerodynamic decelerator clear of the rotors and allowing it to function properly. The device creates reliable and consistent functioning of the aerodynamic decelerator launch system in the event of UAV system failure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing and other features and advantages of the present disclosure will be more readily appreciated as the same become better understood from the following detailed description when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an exploded pictorial view of a valve assembly formed in accordance with the present disclosure;

FIG. 2 is a pictorial view of the valve assembly of FIG. 1 in a fully assembled configuration;

FIG. 3 is a pictorial view of a valve body with O-ring in place in accordance with the present disclosure;

FIG. 4 is a pictorial view of the valve body of FIG. 3 with a first layer of silicone material over the O-ring in accordance with the present disclosure; FIG. 5 is a pictorial view of the valve body of FIG. 4 with a layer of fibrous material over the first layer of silicone material in accordance with the present disclosure;

FIG. 6 is a pictorial view of the valve body of FIG. 6 with a wrap of insulation around a portion of the wire in accordance with the present disclosure;

FIG. 7 is a pictorial view of the valve body of FIG. 7 with a second layer of silicone material over the loop of wire and a portion of the layer of fibrous material in accordance with the present disclosure; and

FIG. 8 is a pictorial view of the valve body of FIG. 8 with a silicone washer placed over the second layer of silicone material.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed implementations. However, one skilled in the relevant art will recognize that the present disclosed implementations may be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, well-known structures or components or both that are associated with the environment of the present disclosure have not been shown or described in order to avoid unnecessarily obscuring descriptions of the implementations.

Unless the context requires otherwise, throughout the specification and claims that follow, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be construed in an open inclusive sense, that is, as "including, but not limited to." The foregoing applies equally to the words "including" and "having."

Reference throughout this description to "one implementation" or "an implementation" means that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation. Thus, the appearance of the phrases "in one implementation" or "in an implementation" in various places throughout the specification are not necessarily all referring to the same implementation. As used herein, the term "aerial vehicle" refers to a powered airborne object controlled by a user or autonomously, such as through an automated position-control system. Examples of aerial vehicles can include, without limitation, unmanned aerial vehicles, drones, manned aerial vehicles, quad copters, rockets, and the like.

As used herein, an aerodynamic "decelerator" refers to any number of devices used to decelerate an aerial vehicle during flight, free fall, or uncontrolled flight, including without limitation a parachutes, drogue chutes, canopies, shrouds, umbrella-like devices, streamers, and inflatable devices such as airbags, balloons, and the like.

It is desirable that an aerodynamic decelerator system be properly deployed with a launch mechanism that removes the aerodynamic decelerator away from the control surfaces, thrust generators, landing gear, propellers, and rotors of the aerial vehicle in order to prevent entanglement. In the design of the present disclosure, a compressible pressurized gas is utilized. To be effective, the gas must inflate the decelerator apparatus instantaneously.

The present disclosure utilizes a solid-state (without moving parts) mechanism that provides a rapid release of a compressible fluid, such as pressurized gas, which causes the decelerator to instantaneously deploy and accelerate while avoiding entanglement with the aerial vehicle.

FIGS. 1 and 2 illustrate an exploded view and an assembled view of a valve assembly 20 formed in accordance with the present disclosure. As shown in the exploded view of FIG. 1, the valve assembly 20 includes a valve body 22, an O-ring 24, a first layer of silicone material 26, a membrane in the form of a layer of fibrous material 28, a loop of wire 30, a second layer of silicone material 32, a silicone ring or washer 34, a cover 36, and fasteners 38 that secure the cover 36 to the valve body 22. FIG. 2 shows the assembled valve assembly 20 attached to the top of an air tank 40.

The valve body 22 is shown having an internal axial bore 42, an intake port 44, and an exit port 46, the intake port 44 and the exit port 46 in fluid communication with the bore 42. The body includes a substantially planar top face 48 with an opening in the exit port 46. A circular channel 50 is formed in the top face 48 that is sized and shaped to receive the O-ring 24 that itself is sized and shaped to encircle the exit port opening 46. This is shown in FIG. 3, in which the valve assembly is in the first stage of construction.

In FIG. 4, the first layer of self-healing silicone material 26 is placed over the O-ring 24 and in contact with the valve body top face 48. The first layer of silicone 26 has an opening 52 formed therein with a diameter that is sized slightly smaller than, and shaped to align with, the exit port opening 46 to permit the passage of gas through the first layer of silicone 26;

The first layer of fibrous material 28 is placed over the first layer of silicone 26 and in contact with the valve body face 48 as shown in FIG. 5. A circle 54 is drawn or printed on the first layer of fibrous material 28 to indicate alignment with the exit port opening 46. The fibrous material 28 is cut into a circular shape to form a wafer, preferably out of Dyneema ^® composite fabrics material, and holes are created for the screws 38 to pass through. In one implementation, a 5/16" circle is drawn or printed in the center of the wafer of fibrous material 28. The membrane or layer of fibrous material 28 is strong enough that it will hold the pressure, but melts at 180 degrees F.

It is to be understood that other fibrous or textile material can be used, such as Nylon, spectra, or high-strength textile material and the like, although they might not hold as much resting pressure, but functionality will be the same. Examples of high-strength fibrous materials include, but are not limited to, reinforced laminates, and composite fabrics, such as Spectra, Dyneema ^® , Dyneema ^® composite fabrics, Cuben Fiber, and Zylon ^® , and other antiballistic material, such as ABC -Matrix ^® , nanocellulose and Kevlar ^® . Other high-strength fibrous materials include ultra-high-molecular-weight polyethylene (UHMWPE) fibers, composites, and fiber-reinforced laminates having UHMWPE fibers.

In FIG. 6 the loop of wire 30 is shown having first and second ends 56, 58 attached to insulated first and second wire leads 60, 62, respectively. The loop of exposed wire 30 is sized and shaped to have a diameter slightly larger than the diameter of the opening 52 in the first layer of silicone 26. Preferably, the loop 30 needs to extend just outside of the O-ring 24. The pattern of the way the Nichrome wire 30 is arranged allows a partial hole to burn quickly, and essentially forms a flap in the membrane, allowing the air to pass through.

The insulated wire leads 60, 62 are wrapped with an insulation, such as a silicone self-healing tape 64 that extends from the loop of wire 30 to beyond the valve body 22 as shown. Ideally the wire leads 60, 62 are silicone insulated 22G lead wires with insulation removed less than or equal to 1/8" from the ends. In assembly, wrap each lead wire with the Nichrome wire and solder in place, and trim the excess lead wire that protrudes past the soldered Nichrome connection. Then wrap the silicone self-healing tape 64 around the remaining extended wires 60, 62, seal it on all sides of the wire leads 60, 62, and cut off the excess tape 64.

The loop of exposed wire 30 is positioned on top of the layer of fibrous material 28 and in alignment with the opening 52 in the first layer of silicone 26 below the layer of fibrous material 28, with the first and second insulated wire leads 60, 62 extending beyond the valve body 22 for connection to a source of electricity. Ideally the wire loop is 32G Nichrome 80 wire that is cut to a length to 1 3/4" long. It is to be understood that the wire need not be formed in a loop, and other shapes may be used depending on the design of the valve body. Any shape that creates a flap when the membrane or fibrous material is burned is suitable and preferred. By creating a flap, the material that separates from the membrane or layer of fibrous material will be partially retained or connected, and not be blown into the deployment apparatus by the escaping fluid.

In FIG. 7 the second layer of self-healing silicone 32 is positioned over the loop of exposed wire 30 and in contact with the layer of fibrous material 28. The second layer of silicone 32 has an opening 66 formed therein with a diameter that is sized slightly smaller than, and shaped to align with, the loop of wire 30, and hence to align with the exit port opening 46, and hence the opening 52 in the first layer of silicone 26, and the loop of wire 30 to permit the passage of gas through the second layer of silicone 32.

FIG. 8 shows the washer of silicone 34 with a central opening 68 having a diameter greater than the diameter of the opening 66 in the second layer of silicone 32. Ideally the central opening is a 7/16" hole in this implementation. The washer 34 is sized and shaped to be placed over the second layer of silicone 32 material without extending beyond the layer of fibrous material 28. Ideally, the washer is 1/16" thick silicone and cut into 1 1/8" circular disk, and it functions to prevent pressurized gas from escaping when the valve assembly 20 opens to let air flow from the tank 40.

Referring again to FIG. 2, it shows the cover 36 sized and shaped to be placed over the top face 48 of the valve body 22 and held in place with the plurality of threaded fasteners 38 to secure the first and second layers of silicone 26, 32, the layer of fibrous material 28, the loop of wire 30, and the washer 34 in concentric alignment. Removable fasteners are preferred in order to enable reuse of the valve assembly 20 by replacing the layer of fibrous material 28 and the loop of wire 30. The cover 36 includes a cylindrical extension 69 with internal threads for connection to a container for the decelerator, such as a parachute.

In one implementation, the valve assembly is constructed out of machined metal, 3D printed metal, or 3D printed plastic. This valve body 22 includes a one-way fill port 70 and a mechanical or digital pressure gauge 72, as well as internal materials not relevant to this disclosure.

Operationally, the valve assembly 20 is just one component of an aerodynamic decelerator launch system. A proprietary control system uses an algorithm to auto detect failure in the UAV flight characteristics. Upon detection of failure, it will trigger a storage capacitor to send 12 V of power to the wires 60, 62, and the Nichrome loop of wire 30 instantly heats, burning a partial hole through the membrane or layer of fibrous material, which allows the pressurized fluid, such as air, to rapidly dump from the tank, through the valve body, through the membrane, and into the decelerator container, thus launching the aerodynamic decelerator. In one implementation a 16V capacitor is used, and the voltage optimal range is 9-12 V.

The valve assembly 20 was created for high pressure use, in one implementation at 3,000 psi or below so that it can be easily recharged locally. A burst disc is a standard safety feature required on all high pressure vessels and is located on the side of the valve body 22 in the event the tank is overfilled.

The device is lightweight and small, having little impact on speed and performance of the aerial vehicle. It also has simplicity of design, thus avoiding failure of mechanical parts. The device is not mechanically actuated and therefore is not susceptible to environmental conditions and potential flight situations.

The device must be mechanically fastened or welded to a pressure vessel. When triggered, the device allows compressible fluid to travel from the pressure vessel, through the device, and to the deployment apparatus, therefore causing the inflatable structure to rapidly inflate to a rigid state, moving the actual opening of the aerodynamic decelerator clear of the rotors and allowing it to properly function. The device creates reliable and consistent functioning of the aerodynamic decelerator launch system in the event of UAV system failure.

On the bottom of the membrane or layer of fibrous material, an additional impermeable layer, such as foil, can be added to prevent air leakage. These and other changes can be made to the implementations in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific implementations disclosed in the specification and the claims, but should be construed to include all possible implementations along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.

The disclosure of U.S. provisional patent application Serial No. 62/501,920, filed May 5, 2017, is incorporated herein in its entirety.