Valve for airbag decelerator
Systems and devices for deceleration of vehicles, such as parafoils descending from high altitude balloons, upon impact with ground. A valve may be configured to release air from within an airbag upon impact of the airbag with ground. The valve may be a one way check valve. The valve may include an axially moveable valve body biased by a spring. An increase in pressure within the airbag due to ground impact overcomes the spring biasing force to move the valve body and release air from the airbag. The released air provides a controlled deceleration due to increased absorption of the impact forces by the deflating airbag. Portions of the valve may be additively manufactured. A valve housing may include flanges that clamp onto the airbag envelope. The valve may be low cost and single use, such that the valve is replaced with a new valve for the next flight.
1 . An airbag decelerator system comprising:
an airbag comprising an envelope defining an interior volume configured to store pressurized air; and
a valve comprising:
a base having a first annular flange defining an opening;
a housing comprising:
a second annular flange,
a sidewall defining a first plurality of openings, and an upper portion extending across an upper end of the sidewall, the upper portion located axially upward from the second annular flange and defining a second plurality of openings,
wherein the first and second annular flanges clamp therebetween a portion of the envelope to secure the valve to the airbag;
a spring configured to axially compress and lengthen;
a guide coupled with the upper portion of the housing and protruding toward the base; and
a valve body supported inside the housing and biased toward the base by the spring to seal the opening and prevent the pressurized air from escaping the interior volume of the airbag to an exterior of the airbag, a portion of the valve body configured to be received by the guide, and wherein the spring is configured to compress upon impact between the airbag and a ground surface such that the valve body unseals the opening to allow the pressurized air to escape the interior volume of the airbag to the exterior of the airbag, and
wherein the first plurality of openings is configured to allow air to exit the housing via the sidewall and the second plurality of openings is configured to allow air to exit the housing via the upper portion upon impact between the airbag and the ground surface.
2 . The system of claim 1 , wherein the spring is conical.
3 . The system of claim 2 , wherein a wide portion of the conical spring faces away from the housing.
4 . The system of claim 1 , wherein the valve body comprises a planar plate moveably axially supported by a stem that extends through the spring.
5 . The system of claim 4 , wherein the stem comprises a threaded longitudinal member and the guide surrounds at least a portion of the stem.
6 . The system of claim 5 , wherein the guide is a bushing, wherein the bushing comprises polytetrafluoroethylene (PTFE).
7 . The system of claim 1 , wherein the housing is additively manufactured.
8 . The system of claim 1 , wherein the valve has a maximum height of 3 inches.
9 . The system of claim 1 , wherein the spring is configured to compress in response to a pressure of the pressurized air exceeding a threshold.
10 . The system of claim 9 , wherein the threshold is 10 pounds per square inch (psi).
11 . A valve for an airbag decelerator system, the valve comprising:
a base having a first annular flange defining an opening;
a housing comprising:
a second annular flange,
a sidewall defining a first plurality of openings, and
an upper portion extending across an upper end of the sidewall, the upper portion located axially upward from the second annular flange and defining a second plurality of openings,
wherein the first and second annular flanges are configured to clamp therebetween a portion of an airbag fabric to secure the valve to an airbag;
a spring configured to axially compress and lengthen;
a guide coupled with the upper portion of the housing and protruding toward the base; and
a valve body supported inside the housing and biased toward the base by the spring to seal the opening, a portion of the valve body configured to be received by the guide, wherein the spring is configured to compress upon impact between the airbag decelerator system and a ground surface such that the valve body unseals the opening, and
wherein the first plurality of openings is configured to allow air to exit the housing via the sidewall and the second plurality of openings is configured to allow air to exit the housing via the upper portion upon impact between the airbag decelerator system and the ground surface.
12 . The valve of claim 11 , wherein the spring is conical.
13 . The valve of claim 12 , wherein a wide portion of the conical spring faces the opening.
14 . The valve of claim 11 , wherein the valve body is supported by a longitudinal member that is received by the guide.
15 . The valve of claim 11 , wherein the housing is additively manufactured.
16 . The valve of claim 11 , wherein the valve has a maximum overall axial height H 1 of 3 inches.
17 . The valve of claim 11 , wherein the spring has a spring constant of between about 3 lbf/in to about 8 lbf/in.
18 . The valve of claim 11 , wherein the guide is positioned within a bore of the housing, the guide configured to move with respect to the housing.
19 . The valve of claim 11 , further comprising a plurality of radial webs protruding from an outer surface of the upper portion of the housing.
20 . A high altitude platform comprising:
a lighter than air system configured to lift a payload off a ground to an altitude above 50,000 feet; and
an airbag decelerator system configured to provide cushioning to the payload upon returning to ground, the airbag decelerator system comprising:
an airbag comprising an envelope defining an interior volume configured to store pressurized air; and
a valve comprising:
a base having a first annular flange defining an opening;
a housing comprising:
a second annular flange,
a sidewall defining a first plurality of openings, and
an upper portion extending across an upper end of the sidewall, the upper portion located axially upward from the second annular flange and defining a second plurality of openings,
wherein the first and second annular flanges clamp therebetween a portion of the envelope to secure the valve to the airbag;
a spring configured to axially compress and lengthen;
a guide coupled with the upper portion of the housing and protruding toward the base; and
a valve body supported inside the housing and biased toward the base by the spring to seal the opening and prevent the pressurized air from escaping the interior volume of the airbag to an exterior of the airbag, a portion of the valve body configured to be received by the guide, and wherein the spring is configured to compress upon impact between the airbag and a ground surface such that the valve body unseals the opening to allow the pressurized air to escape the interior volume of the airbag to the exterior of the airbag,
wherein the first plurality of openings is configured to allow air to exit the housing via the sidewall and the second plurality of openings is configured to allow air to exit the housing via the upper portion upon impact between the airbag and the ground surface.
21 . The high altitude platform of claim 20 , wherein the spring is conical.
22 . The high altitude platform of claim 20 , wherein the housing is additively manufactured.
23 . The high altitude platform of claim 20 , wherein the valve body is supported by a longitudinal member extending through the guide.
24 . The high altitude platform of claim 20 , wherein the valve has a maximum height of 3 inches.