Methods to improve the opening performance of large ram-air parachutes

Abstract

This invention discloses a method for improving the opening performance of a large ramjet parachute. The method involves constricting the two side air chambers, folding and constricting the trailing edge lines extending from both sides of the trailing edge, and combining the constraint structures on the air chambers and trailing edge lines on the same side. This allows the air chambers and trailing edge lines to gradually release their constraints simultaneously as the air chambers inflate to a certain extent. In the initial opening phase, the middle air chamber begins to inflate, and the trailing edge lines are kept taut due to the constraint on their extended portions, preventing tangling. After the middle air chamber is fully inflated, the two side air chambers begin to inflate. As the air chambers inflate to a certain extent, the constraints on the air chambers and trailing edge lines are gradually released simultaneously, allowing the air chambers to gradually unfold and the trailing edge lines to gradually lengthen until the canopy is fully inflated. This method effectively prevents the trailing edge lines from tangling around the top of the canopy during the initial opening phase of a large ramjet parachute and reduces the instantaneous opening impact force.

Description

Technical Field

[0001] This invention relates to ram-air parachutes, and more specifically to a method for improving the opening performance of large ram-air parachutes. Background Technology

[0002] Ram-air parachutes inflate with ram air to form an airfoil. They maintain a specific installation angle by using parachute lines of varying lengths that increase sequentially from the leading edge to the trailing edge along the chord. This controls the angle of attack after deployment, achieving a balance between lift and drag after stable inflation and deployment, resulting in excellent gliding performance.

[0003] For small parachutes, the chord length is relatively short, so the number of parachute lines distributed along the chord is small, and the length difference between the leading and trailing edges is not too large. However, as the area of ​​the ram-air parachute increases, not only does the density of parachute lines distributed along the chord increase, but the length difference between the parachute lines also becomes larger and larger, especially between the leading and trailing edge parachute lines, where the length difference can sometimes reach several meters or more. This raises a significant problem:

[0004] During the deployment of a large ramjet parachute, shorter lines tend to straighten earlier under stress. However, for ramjet parachutes where the canopy is still in a coiled state, the trailing edge lines, which extend for several meters, are essentially slack at the moment of deployment. During the disordered deployment process, these lines swing erratically and are likely to get tangled in the partially inflated canopy or other lines. Once tangled, the large ramjet parachute can no longer inflate fully on its own, leading to system failure. In mild cases, the canopy may be damaged, the lines may break, and the partially inflated system may become uncontrollable, causing an uncontrolled fall. In severe cases, the canopy may fail to deploy, leaving the system in a state of free fall and resulting in a crash.

[0005] For the reasons mentioned above, some methods for restraining the protruding paracords are currently used in the packaging process of large stamped parasols. For example, the excess paracords are folded in a Z-shape and then restrained to the end of the paracords using a fixed force rope or elastic rope. However, with this method, the restrained paracords will be pulled out instantly by the airflow when the parasol opens, and the above problem will still occur. This is because the excess paracords that are bundled together are also in a slack state when they are pulled out, which cannot completely solve the above problem. Summary of the Invention

[0006] The purpose of this invention is to provide a method for improving the opening performance of large ramjet parachutes. This method can effectively prevent the trailing edge parachute lines from wrapping around the top of the parachute in the initial opening stage, while also reducing the instantaneous opening impact force.

[0007] The technical solution adopted in this invention is:

[0008] A method for improving the opening performance of a large ramjet parachute involves constricting the two side air chambers, folding and constricting the trailing edge parachute lines extending from both sides of the trailing edge, and combining the constraint structures on the air chambers and trailing edge parachute lines on the same side. This allows the air chambers and trailing edge parachute lines to gradually release their constraints simultaneously when the air chambers on both sides are inflated to a certain extent. In the initial stage of opening, the middle air chamber begins to inflate, and the trailing edge parachute lines are under tension due to the constraint on their extended portions, thus preventing the trailing edge parachute lines from tangling. After the middle air chamber is fully inflated, the two side air chambers begin to inflate. When the air chambers on both sides are fully inflated, the air chambers and trailing edge parachute lines on both sides gradually release their constraints simultaneously, allowing the air chambers on both sides to gradually unfold and the trailing edge parachute lines on both sides to gradually lengthen until the canopy is fully inflated.

[0009] Preferably, the common limiting structure for the air chamber and trailing edge parachute lines includes a limiting ring, a rope loop, a first constraint rope, a second constraint rope, a stabilizing rope, and a limiting hook. The limiting ring is distributed on the leading edge and both sides of the air chamber retraction area on the lower wing surface. The rope loop is located near the trailing edge of the air chamber retraction area on the lower wing surface and corresponds one-to-one with the folded trailing edge parachute lines. The first constraint rope is connected to the stabilizing rope at both ends to form a loop around the air chamber retraction area. The stabilizing rope passes through the limiting ring at the leading edge. The first constraint rope passes through the limiting rings on both sides in sequence and forms a connecting section near the rope loop. The trailing edge parachute line is folded in half, passes through the corresponding rope loop, and is fixed to the connecting section of the first constraint rope by the second constraint rope. The limiting hook is distributed on both sides of the first constraint rope. When the limiting hook moves towards the trailing edge, it can pass through the limiting ring; when it moves towards the leading edge, it is blocked by the limiting ring.

[0010] Preferably, the limiting hook is a V-shaped elastic metal part with its opening facing the front edge and its tip facing the rear edge.

[0011] Preferably, the limiting rings are distributed on both sides of the air chamber closing area according to the position of the parachute chordal lines, and the distribution spacing of the limiting hooks on both sides of the air chamber closing area is the same as the distribution spacing of the parachute chordal lines.

[0012] Preferably, the cord loop is sewn onto the lower wing surface.

[0013] Preferably, the two air chambers are compressed using an accordion bellows design.

[0014] Preferably, the rear paracord is folded in half in the area below the rear cord loop.

[0015] The beneficial effects of this invention are:

[0016] This method can effectively prevent the trailing edge parachute lines from wrapping around the top during the initial opening of a large ram-air parachute, and allows the canopy to unfold a second time, thus extending the opening time. In other words, it also reduces the instantaneous opening impact force. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the initial state of the umbrella opening according to the present invention.

[0018] Figure 2 This is a schematic diagram of the common limiting structure of the air chamber and the trailing paracord in this invention.

[0019] Figure 3 This is a schematic diagram of the invention after it is fully inflated.

[0020] In the diagram: 1. Leading edge; 2. Trailing edge; 3. Lower wing surface; 4. Restraint rope one; 5. Rope loop; 6. Trailing edge paracord; 7. Limiting ring; 8. Limiting hook; 9. Restraint rope two; 10. Trailing edge rope buckle; 11. Stress rope; 12. U-shaped ring. Detailed Implementation

[0021] The application will be further described below with reference to the accompanying drawings and embodiments.

[0022] This application discloses a method for improving the opening performance of a large ramjet parachute. The primary purpose is to prevent the trailing edge parachute lines 6 from wrapping around the top during the initial opening phase of the large ramjet parachute. The principle is as follows: the two side air chambers are gathered and constrained, and the trailing edge parachute lines 6 extending from both sides of the trailing edge 2 are folded and constrained. The constraining structures on the air chambers on the same side and the trailing edge parachute lines 6 are combined, so that when the two side air chambers are inflated to a certain extent, the two side air chambers and the trailing edge parachute lines 6 can simultaneously and gradually release their constraints. In the initial opening phase, the middle air chamber begins to inflate, and the trailing edge parachute lines 6 are under tension due to the constrained extension, thus preventing the trailing edge parachute lines 6 from wrapping. After the middle air chamber is fully inflated, the two side air chambers begin to inflate. When the two side air chambers are inflated to a certain extent, the two side air chambers and the trailing edge parachute lines 6 simultaneously and gradually release their constraints. The two side air chambers gradually unfold, and the two side trailing edge parachute lines 6 gradually lengthen until the canopy is fully inflated. This method can effectively prevent the trailing edge parachute ropes 6 from wrapping around the top during the initial opening of a large ram-air parachute, and allows the canopy to unfold a second time, thus extending the opening time. In other words, it also reduces the instantaneous opening impact force.

[0023] According to the above scheme, the common limiting structure of the air chamber and the trailing edge paracord 6 is the key to this application. In this embodiment, preferably: Figure 2As shown, the common limiting structure for the air chamber and trailing edge parachute lines 6 includes a limiting ring 7, a cord loop 5, a first restraint cord 4, a second restraint cord 9, a stabilizing cord 11, and a limiting hook 8. The limiting ring 7 is distributed on the leading edge 1 and both sides of the air chamber retraction area on the lower wing surface 3. The cord loop 5 is located near the trailing edge 2 of the air chamber retraction area on the lower wing surface 3 and corresponds one-to-one with the folded trailing edge parachute lines 6. The first restraint cord 4 is connected at both ends to the stabilizing cord 11, forming a loop around the air chamber retraction area. The stabilizing cord 11 passes through the limiting ring 7 on the leading edge 1. The first restraint cord 4 passes through the limiting rings 7 on both sides in sequence and forms a connecting section near the cord loop 5. The trailing edge parachute lines 6 are folded in half, pass through the corresponding cord loop 5, and are fixed to the connecting section of the first restraint cord 4 by the second restraint cord 9. The limiting hook 8 is distributed on both sides of the first restraint cord 4. When the limiting hook 8 moves towards the trailing edge 2, it can pass through the limiting ring 7; when it moves towards the leading edge 1, it is blocked by the limiting ring 7. In the initial stage of parachute opening, as... Figure 1 As shown, due to the restraint of constraint rope 4 and the stabilizing rope 11, the air chamber retraction area is in a restricted state, with only the middle air chamber beginning to inflate. The trailing parachute rope 6, due to its extended portion being restrained, is under tension, thus preventing entanglement. Simultaneously, the trailing edge 2 is pulled down. After the middle air chamber is fully inflated, the two side air chambers begin to inflate, and the tension on the stabilizing rope 11 gradually increases. When the two side air chambers reach a certain level of inflation, the stabilizing ropes 11 on both sides break, releasing the restraints on both side air chambers and the trailing parachute rope 6. Subsequently, the trailing edge 2 pulls down, causing the trailing parachute rope 6 to gradually lengthen. The trailing parachute rope 6, through constraint rope 2 9, pulls the limiting hook 8 on constraint rope 4, which passes through the limiting ring 7 and moves towards the trailing edge 2. Simultaneously, the two side air chambers gradually unfold, as... Figure 3 As shown, the parachute will continue to inflate until it is fully inflated, and then the parachute will slide steadily down to the upper end of the U-shaped ring 12 to begin stable gliding.

[0024] Based on the common limiting structure of the air chamber and the trailing parachute rope 6 described above, in this embodiment, preferably, as follows: Figure 2 As shown: The limiting hook 8 is a V-shaped elastic metal part with its opening facing the front edge 1 and its tip facing the rear edge 2; the limiting ring 7 is distributed on both sides of the air chamber closing area according to the position of the parachute chordal parachute lines, and the distribution spacing of the limiting hook 8 on both sides of the air chamber closing area is the distribution spacing of the parachute chordal parachute lines; the rope binding sleeve 5 is sewn on the lower wing surface 3; the air chambers on both sides are closed and compressed in the form of an accordion bellows; the rear edge parachute lines 6 are folded in half in the area below the rear edge rope buckle 10.

[0025] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A method of improving the opening performance of a large ram-air parachute, characterized by: The two side gas chambers are constrained, the trailing edge umbrella ropes on both sides of the trailing edge are folded and constrained, and the constraint structures on the same side of the gas chamber and the trailing edge umbrella rope are combined, so that the two side gas chambers and the trailing edge umbrella rope can be gradually released at the same time when the two side gas chambers are inflated to a certain degree; in the initial stage of opening the parachute, the middle gas chamber starts to inflate, and the trailing edge umbrella rope is in a force-tight state due to the constraint of the protruding part, thereby avoiding the winding of the trailing edge umbrella rope, and when the middle gas chamber is inflated and full, the two side gas chambers start to inflate, and when the two side gas chambers are inflated to a certain degree, the two side gas chambers and the trailing edge umbrella rope are gradually released at the same time, the two side gas chambers are gradually unfolded, and the two side trailing edge umbrella ropes are gradually stretched, until the canopy is inflated and full.

2. The method of improving the opening performance of a large ram-air parachute according to claim 1, characterized in that: The common limiting structure of the gas chamber and the trailing edge umbrella rope includes a limiting ring, a binding rope sleeve, a constraint rope one, a constraint rope two, a constant force rope, and a limiting hook, the limiting ring is distributed on the leading edge and both sides of the gas chamber constriction area on the lower wing surface, the binding rope sleeve is arranged near the trailing edge of the gas chamber constriction area on the lower wing surface and corresponds to the folded trailing edge umbrella rope one by one, the constraint rope one is connected with the constant force rope at both ends to form a ring around the gas chamber constriction area, the constant force rope passes through the limiting ring of the leading edge, the constraint rope one passes through the limiting rings on both sides in sequence and forms a connecting section near the binding rope sleeve, the trailing edge umbrella rope passes through the corresponding binding rope sleeve after being folded and is fixed on the connecting section of the constraint rope one through the constraint rope two, the limiting hook is distributed on both sides of the constraint rope one, and the limiting hook can pass through the limiting ring when moving towards the trailing edge and is blocked by the limiting ring when moving towards the leading edge.

3. The method of improving the opening performance of a large ram-air parachute according to claim 2, characterized in that: The limiting hook is a V-shaped elastic metal piece, the opening of which faces the leading edge, and the tip thereof faces the trailing edge.

4. The method of improving the opening performance of a large ram-air parachute according to claim 2, wherein: The limiting ring is distributed according to the position of the wing parachute chord towards the umbrella rope on both sides of the gas chamber constriction area, and the distribution interval of the limiting hook on both sides of the gas chamber constriction area is the distribution interval of the wing parachute chord towards the umbrella rope.

5. The method of enhancing the opening performance of a large ram-air parachute according to claim 2, wherein: The binding rope sleeve is sewn on the lower wing surface.

6. A method of improving the opening performance of a large ram-air parachute according to any one of claims 1 to 5, characterized in that: The two side gas chambers are folded and compressed in the form of an accordion bellows.

7. A method of improving the opening performance of a large ram-air parachute according to any one of claims 1 to 5, characterized in that: The trailing edge umbrella rope is folded at the area below the trailing edge rope buckle.

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