US3429531A

US3429531A - Deployment bag and method of packing

Info

Publication number: US3429531A
Application number: US555184A
Authority: US
Inventors: Oscar W Sepp
Original assignee: STEINTHAL AND CO Inc M
Current assignee: STEINTHAL AND CO Inc M; M Steinthal and Co Inc
Priority date: 1966-06-03
Filing date: 1966-06-03
Publication date: 1969-02-25
Anticipated expiration: 1986-02-25

Description

Feb. 25, 1969 Filed June 5, 1966 O. W. SEPP DEPLOYMENT BAG AND METHOD OF PACKING I Sheet J v INVENTOR.

Feb. 25, 1969 o. w. SEPP 3,429,531

DEPLOYMENT BAG AND METHOD OF PACKING Filed June s, 1966, Sheet 2 of 4 INVENTOR. 50m h 5.5

Feb. 25, 1969 o. w. SEPP 3,429,531

DEPLOYMENT BAG AND METHOD OF PACKING Filed June a, 1966 Sheet 3 of 4 INVEN TOR.

Aim/P M 55 O. W. SEPP DEPLOYMENT BAG AND METHOD OF PACKING Feb. 25, 1969 Sheet Filed June 5, 1966 INVENTOR.

United States Patent 16 Claims ABSTRACT OF THE DISCLOSURE A deployment bag with a velocity discriminating flap comprised of two overlying sheets of material which are spread apart at the opening edge of the flap by spring biased stiffening means to present a projected area to the on-rushing air in the direction opposite to vehicle movement. The top sheet is maintained spread out over the fiap by the stiffening means to present a projected area to the on-rushing air in the direction opposite to bag ejection. A separate sheet of material is positioned within the bag between the parachute and closure flaps to serve as a packing aid to hold down the parachute while the flaps are "being closed. Separable lines pass adjacent this sheet and out of the bag through holes in the bag. When the flap is closed, the lines are removed and the sheet is withdrawn without opening the flaps.

This invention relates to parachute systems; particularly to the portion of such systems known as the deployment bag.

A parachute system of the kind described herein, consists of three principal parts:

(1) The main canopy which, together with its suspension lines and riser, supports the load in its descent.

(2) The pilot chute, much smaller in size than the main canopy, which is first to inflate to aid in deploying the main canopy.

(3) The deployment bag, which holds the main canopy and its suspension lines folded within it. The deployment bag is generally stowed in a restricted compartment within the aircraft.

In normal orderly deployment, the deployment bag is ejected from the aircraft or capsule with the riser extending from the deployment bag. Shortly thereafter the pilot chute emerges from the deployment bag, engages the air stream and inflates. The inflated pilot chute then aids in an orderly deployment of the main canopy.

Orderly deployment of the main canopy is the critical part of the deployment operation. In an orderly deployment, the riser, then the suspension lines and then the main canopy pay out of the deployment bag. The main canopy then inflates and supports the load in its descent.

A major design and performance problem in parachute systems has been the limited space available within the aircraft or capsule in which to stow the deployment bag. Notwithstanding this limitation, the weight of the loads and the speeds at which orderly deployment must take place are such that the main canopy is very large relative to the size allowed for the deployment bag in which it must fit. As a result, packing the main canopy and its shroud lines within the deployment bag has been difiicult and often unsatisfactory.

This invention tackles this problem and has for an object, a method of packing parachutes within deployment bags where the size of the bag presents packing difliculties.

This invention also has as an object a packing aid which will work in conjunction with the bag, not in interference to it and will permit the normal packing and closing of the deployment bag according to its design and a successful deployment thereafter.

Another object of this invention is a packing aid which will hold a relatively large canopy compressed within a restricted portion of the bag and which is removable from the 'bag prior to closure.

An overall object of this invention is to add a new feature to deployment bags which overcomes the principle packing problem and thus provides a breakthrough which enables designers to work within size and configuration limitations which have heretofore dogged their design efforts.

These objects are successfully accomplished by the addition of a new component to parachute systems: the fabric retainer. The fabric retainer is a packing aid comprised of a flexible piece, such as a sheet of fabric, which is placed upon the main canopy prior to finally compressing it within its portion of the bag. The fabric piece has separable lines threaded through loops across its face and extending through holes in the bag to the bag exterior. When the canopy is compressed into its alloted space within the bag, the fabric retainer holds the canopy in its compressed position while the canopy locking flaps within the bag are closed and locked. Thereafter, the separable lines are pulled out of the bag through the holes in the bag and the fabric retainer is itself pulled out of the bag from beneath the closed canopy locking flaps 'by an extending strap appropriate for that purpose.

A related problem in deployment deals with successfully ejecting the pilot chute from the bag. Various methods for ejecting the pilot chute have been used. But none of these methods employ a positive means within the pilot chute flap of the deployment bag and none of these methods are velocity discriminating.

As dictated by the design and performance requirements of the aircraft or capsule, it may be necessary to eject the deployment bag at high catapult ejection velocities. If the aircraft or capsule is moving at relatively slow speed at the time of catapult ejection, the pilot chute may not perform its intended function. Instead, the pilot chute may trail behind the swiftly catapulted deployment bag and prevent orderly deployment of the main canopy. On the other hand, if the vehicle is traveling at a fast speed when the deployment bag is catapulted the pilot chute will quickly get out into the fast air stream and perform as intended.

It is therefore an object of this invention to provide a deployment bag which is velocity discriminating. That is, a bag which will automatically permit the pilot chute to enter the air stream when the vehicle from. which the bag is catapulted is traveling at high speeds, but which will not permit the pilot chute to enter the air stream when the vehicle is traveling at slow speeds.

At slow vehicle speeds, the high catapult velocity of the bag will be sufiicient to deploy the main canopy in an orderly manner without the aid of the pilot chute.

It is another object of the invention to utilize a portion of the deployment bag itself as a means for releasing the pilot chute from the bag into the air stream.

A further object of the invention is to enable utilization of pilot chutes which are simplified in design and construction by eliminating the ejecting mechanisms which might otherwise be closely associated with the pilot chute.

These objects are satisfied in the present invention by utilizing in the deployment bag, a spring-loaded flap which is arranged, upon deployment of the bag, to raise up in the forward direction and present a projected area to the air stream from the forward direction. The flap is pushed open by the force exerted by the air stream, exposing the pilot chute which was packed to lie beneath it.

A line connects the pilot chute to the flap and the pilot chute is pulled to follow the flap into the air stream to be inflated.

These objects and features of the invention will be fully understood with reference to the accompanying detailed description and drawings in which:

FIGURE 1 is a pictorial representation of a vehicle showing a deployment bag installed in a stowage compartment and the various stages of successful deployment.

FIGURE 2 is a prospective view of a fully packed deployment bag.

FIGURE 3 is a prospective view of the fabric retainer.

FIGURE 4 is a prospective view of the packing of a deployment bag using the fabric retainer.

FIGURE 5 is a sectional view of the deployment bag at the point in packing when the canopy locking flaps are closed.

FIGURE 6 is a view of the top flap of the bag in the closed position.

FIGURE 7 is a view of the top flap in its spread condition.

FIGURE 8 is another pictorial representation of the various stages of successful deployment without release of the pilot chute.

Parachute systems of the general kind described are used to recover capsules or other loads, in which case they are referred to as recovery parachute systems. They are also used to decelerate and stabilize aircraft and are referred to as deceleration parachute systems or drag chute systems. Whether used for recovery, deceleration, stabilization, or for any other purpose to which such systems may be employed, it should be understood that the present invention is intended to be applicable to these parachute systems no matter how employed.

For the purpose of this specification, the parachute system is described with reference to the recovery of the aircraft capsule 1 in FIGURE 1. The recovery parachute system is shown by the deployment bag 10 stowed within its stowage compartment 2 which is positioned behind the cockpit 3. The deployment bag 10 is connected to the capsule 1 by the riser 11 and rests on a catapult mechanism 4 below the compartment door 5. The catapult 4 and the other details of the stowage compartment 2 are known in the art in a plurality of designs and do not form part of this invention and therefore are shown generally.

The deployment bag 10 conforms dimensionally to the space available for it within the stowage compartment 2. The main canopy is stowed within the deployment bag and is connected to the capsule 1 through its suspension lines, which are also stowed within the deployment bag,

and the riser 11.

In emergency situations where the aircraft becomes disabled in flight, the capsule 1 is designed to separate from the remainder of the aircraft, shown generally in phantom, to be recovered by the recovery parachute system. Separation of the capsule 1 and deployment of the parachute system may occur at high aircraft speeds. High speed deployment and the weight of the capsule and its occupants requires a large main canopy to successfully recover the capsule. As a result, the size limitations on the deployment bag 10 due to the limited space available for it within the compartment 2 presents the practical problem of packing the large main canopy and its suspension lines within a very restricted volume.

In FIGURE 2, the deployment bag 10 is shown fully packed prior to being stowed. The arrow on the top flap, the pilot chute flap 12, indicates the forward orientation of the deployment bag 10 when stowed within the stowage compartment 2. The riser 11 will be connected to the capsule at its loop 13. The main canopy is packed within the bag in the space above the aligned grommet holes 14. The canopy suspension lines and the upper length of the riser 11 are packed within the deployment bag 10 below the grommet holes 14. The packing of the bag is completed by lacing closed the bottom flap of the bag by passing loops of the lacing 15 through the bottom line of grommet holes 16. I

The bag 10 is comprised of a single piece of nylon fabric, folded to form the sides and bottom flap. The design of the top flap 12 will be described hereafter. Reinforcing ribbons 17 are stitched to the bag at various places.

Due to the special configuration of the stowage compartment 2 in which the bag must fit, the bag 10 is wider towards its top. Consequently, the bag is split vertically along the separation 18 and laced closed by lacing 19 through grommets 20. 1h deployment, the bag separates vertically at separation 18 to permit the main canopy, which is packed towards the top, to come out of the bottom.

The riser 11 is held along a vertical edge of the bag 10 by the break-ties 21. Straps 22 extend from the riser 11 near the top of the bag 10 and are connected to breakties 23 which hold the top flap 12 closed. The pilot chute is packed and retained beneath the top flap 12.

Referring to FIGURES 1 and 2, in deployment, the compartment door 5 opens and the bag 10 is catapulted upwards out of the stowage compartment 2.

The riser 11 which is attached at its loop 13 to the capsule, is pulled down, breaking the various break-ties 21 and pulling the straps 22 to break the break-ties 23. The pull of the riser 11 also opens the bottom lacing 15 and the vertical lacing 19 to permit the orderly deployment of the riser 11, the canopy suspension lines 24 and the canopy 25 from the bottom of the bag.

Just prior to the deployment of the canopy 25 and its suspension lines 24, the top flap 12 is released to open as a result of the breaking of break-ties 23. The top flap 12 opens and the pilot chute 26 which is stowed beneath it, enters the air stream and inflates. The pilot chute 26 aids in the orderly deployment of the suspension lines 24 and the main canopy 25.

The successive stages of deployment of the deployment bag 10, commences with the catapulting of the bag 10 from the stowage compartment 2, through opening of the pilot chute flap 12 releasing the pilot chute 26, to full deployment and inflation of the main canopy 25.

FIGURE 3 shows the fabric retainer 30 which is the packing aid used in aid of packing large canopy parachutes in compartments of restricted volume within deployment bags. The fabric retainer 30 is comprised of a sheet 31 of flexible material such as nylon fabric. Ribbon 32 is stitched around the edges of the flexible sheet 31 so as to form loops 34 with the flexible sheet 31. Lines 33 pass through the loops 34 and lie upon the face of the flexible sheet 31. These lines 33 extend a considerable distance beyond opposite edges of the flexible sheet 31 and can be pulled out of the loops 34 so as to become completely separated from the fabric retainer 30. A flexible strap 35 is stitched to the flexible sheet 31, which is cut at one corner 67.

The use of the fabric retainer 30 in packing a large canopy within a restricted compartment will be fully understood with reference to FIGURES 4 and 5. The deployment bag 10 is packed in an upended position so that the top flap 12 is shown at the bottom.

The deployment bag is divided into compartments. The main canopy 25 is packed within the top compartment (the lower compartment shown in FIGURE 5). The division between compartments is formed by overlapping flaps within the bag 10. Within the bag 10, the canopy 25 is separated from the suspension lines 24 by canopy locking flaps 41 and 42. The canopy 25 is separated from its suspension lines 24 to permit orderly deployment of the parachute from the bag, so that the suspension lines 24 will pay out fully from the deployment bag 10 before the canopy locking flaps open to permit the canopy to follow.

In order to pack the canopy 25 within the limited space available for it within the bag 10, it is known in the art to use a hydraulic press, shownpictorially at 43, to successively compress larger and larger portions of the canopy within the canopy compartment 40. When the canopy is fully compressed, the hydraulic press 43 is lifted and the canopy locking flaps 41 and 42 are closed over the canopy 25 and locked by passing a loop of the suspension lines 24 through fabric rings 44 of flap 41 which extend through slots 66 in fla'p 42.

When the canopy 25 is large relative to the canopy compartment 40, great difliculty is experienced in closing the canopy locking flaps 41 and 42 properly over the canopy 25 because the greatly compressed canopy expands when the press 43 is removed. This difliculty is overcome by installing the fabric retainer over the canopy prior to the final compression by press 43, as shown in FIGURE 4. Then the lines 33 are threaded at both ends through grommets 14.

The press 43 is lowered to fully compress the canopy 25 within its compartment 40. While the canopy is kept fully compressed, the lines 33 are pulled taut and held. When the press 43 is raised, the canopy is held fully compressed by the fabric retainer 30 so that the canopy locking flaps 41 and 42 can be readily closed and locked over the canopy 25.

The fabric retainer 30 is then removed from the deployment bag without opening the flaps 41 and 42. First, the separable lines 33 are released and pulled out of the bag through grommets 14. Then the flexible sheet 31 is removed from beneath the flaps 41 and 42 by pulling up the flexible strap which was positioned to extend out of the bag 10 from behind the flaps 41 and 42. The flexible sheet 31 follows the straps 35 out of the bag by lifting along the inside wall of the bag 10 and past the flaps 41 and 42.

Referring to FIGURES 2, 6 and 7, the deployment bag 10 has a top flap 12 which is held down in a closed position on top of the deployment bag 10 by tying together loops on the flap and loops 51 on the bag with breakties 23. The bag 10 is not open under the top flap, but has a permanently closed cloth inner top 52. The pilot chute 26 lies packed between the inner top 52 and the top flap 12. The pilot chute 26 will escape into the air stream when the top flap or pilot chute flap 12 is released from its closed position and uncovers the pilot chute 26.

The means by which this is accomplished will now be described. The pilot chute flap 12 is comprised of two

overlying sheets

53 and 54 of flexible material, such as the nylon fabric normally used in deployment bags.

Flexible sheets

53 and 54 are joined together by stitching at their rear and sides, but are free to spread apart at their forward ends.

Located between the

flexible sheets

53 and 54 is a spring mechanism 57. Spring mechanism 57 is comprised of two individual spring members 58 and 59 which are linked together at their coil portions by clip 60. The feet of spring members 58 and 59 are held to the inner faces of the flexible sheets 53 and 54 'by hinged

rods

61 and 62 which are held in place by cloth pieces and 63 stitched to the

flexible sheets

53 and 54. The

rods

61 and 62 converge and terminate at cap clip 64.

In the closed position, when the

flexible sheets

53 and 54 overlie each other, the spring mechanism 57 lies compressed between the

sheets

53 and 54, its spring force being biased to urge the

flexible sheets

53 and 54 apart. A break-line 65 is connected between the pilot chute flap 12 and the pilot chute 26 beneath it. The top flap 12 is joined at the top rear edge of the deployment bag 10 by stitching.

The top flap 12 operates to release the pilot chute 26 as follows. Upon catapulting of the deployment bag 10 from its stowage compartment 2, the riser 11 pulls down and away from the bag, breaking break-ties 23 as it does. The top flap 12 is thereby released and the spring mechanism 57 with the top flap 12 is free to operate.

Spring mechanism 57 operates by spreading apart the

flexible sheets

53 and 54 to the limits permitted by the configuration. The effect of this is that the upper sheet 53 raises up and a projected area bounded by the

sheets

53 and 54 is presented to the air stream coming from the forward direction. The air stream exerts a dynamic pressure, q, against the

spread sheets

53 and 54 and a resultant force related to the projected area, where q= /2 rv v is the velocity of the air stream and r is the density of the air and may be taken as 2.38 1()- lb.-sec. /ft. at sea level. This resultant force pushes the pilot chute flap 12 fully open to release the pilot chute 26 into the air stream.

Another force operates in the downward direction and tends to retain the top flap 12 down and closed over the pilot chute. This force results from the air pressure acting downward on the top of the pilot chute flap 12 due to the catapulated movement of the deployment bag in the upward direction. This force is determined in the same way as the force from the forward direction. It can be seen that these forces oppose each other with respect to opening the top flap, and that the critical determiners are the speed of the vehicle in the forward direction at the instant the deployment bag is catapulated, the upward catapult velocity of the deployment bag, and the dimensions of the top flap 12 and the spread between the

flexible sheets

53 and 54 which determine the projected areas in the forward and upward directions.

With these parameters, considerable design and operational freedom is made possible. The deployment bag may be catapulated upward at a velocity low enough so that the force from the forward direction will be suflicient to fully open the top flap 12 and release the pilot chute 26 at the slowest vehicle speed for which deployment is contemplated. The upward catapult velocity of the bag 10 may be increased, whereby the top flap 12 tends to become velocity discriminating. As a result, a critical minimum vehicle forward velocity can be established by design intent, below which the pilot chute flap will not open sufficiently to release the pilot chute to the air stream. FIGURE 8 shows the stages of successful deployment at vehicle forward speeds below the critical minimum speed. The deployment bag 10 is shown to catapult from the vehicle, then the top flap 12 raises up, but thereafter the top flap fails to open to release the pilot chute. The catalpult velocity of the deployment bag 10 is adequate to deploy the suspension lines 24 and then the canopy 25 without the aid of the pilot chute. At slow forward vehicle speeds and fast upward catapult velocities, had the pilot chute been released into the air stream, it could well not have inflated. Instead, it might have upended and trailed below the bag 10 as it catapulated upward. In this condition, rather than aid in the orderly deployment of the main canopy, the pilot chute 12 would pose the threat of entangling the canopy and preventing its inflation. Hence, where high catapult velocities are required, such as may be necessary for near-to-ground level emergency ejections, velocity dis crimination as described, is a valuable asset.

What is claimed is:

1'. In combination, a deployment bag for containing a parachute packed therein having flap means for closing olf at least a portion of said parachute within at least a portion of the interior of said bag and a plurality of apertures spaced about said bag and aligned generally with said flap means when closed, said apertures being arranged in a plurality of pairs of apertures spaced from each other across the interior of said bag, and an aid for packing said parachute in said bag comprising a sheet of flexible material separate and withdrawable from said bag positioned within and substantially across the interior of said bag to lie spread between said parachute and said flap means when closed, a plurality of elongated flexible lines separably attached to said sheet and extending adjacent said sheet within and across the interior of said bag and through respective ones of said pairs of spaced apertures to the exterior of said bag and extraction means for withdrawing said sheet from said bag attached within the interior of said bag to said sheet.

2. The combination in accordance with claim 1 in which said extraction means is attached to said sheet adjacent one face of said flap means and extends between said flap means and a side of said bag beyond the opposite face of said flap means.

3. A deployment bag adapted to be ejected from a moving vehicle, said bag having a flap positioned on said bag at the end thereof in the ejection direction with its opening edge in the direction of vehicle movement, said flap retaining a parachute thereunder, spring biased stiffening means secured to said flap for raising a portion of said flap at said opening edge upon release of said flap to establish a projected area in the direction of vehicle movement and for maintaining said flap substantially spread out after release to establish a projected area in the ejection direction and means for releasing said flap upon ejection of said bag.

4. A deployment bag is accordance with claim 1 in which said spring biased stiffening means comprises stiffening members secured to each of said sheets and spring means operably connected to said members to spread apart said sheets a distance predetermined in relation to the area of said flap to establish a force of air against said flap in the direction opposite vehicle movement of sufiicient magnitude to overcome the effect of the force of the air against said flap in the direction opposite bag ejection to open said flap at vehicle velocities above a predetermined velocity.

5. A deployment bag in accordance with claim 3 in which said spring biased stiffening means comprises stiffening means secured to said flap and spring means operably connected to said stiifening means to raise said portion of said flap at said opening edge a distance predetermined in relation to the area of said flap to establish a force of air against said flap in the direction opposite vehicle movement of sufiicient magnitude to overcome the effect of the force of air against said flap in the direction opposite bag ejection to open said flap at vehicle velocities above a predetermined velocity.

6. A deployment bag in accordance with claim 1 in which said spring biased stiffening means comprises a first pair of elongated stiffening members secured to a first of said sheets and a second pair of elongated stiffing members secured to the second of said sheets, said stiffening members converging away from said opening edge, means for retaining said stiffening members in converging relation, and spring means attached to said stiffening members and biased to urge said pairs of stiffening members apart upon release of said flap.

7. A fabric retainer for use as a packing aid in a deployment bag, said fabric retainer comprising a sheet of flexible material separate and withdrawable from said deployment bag and adapted to lie within and substantially across the interior thereof, a plurality of elongated flexible lines separate and withdrawable from said deployment bag and adapted to lie within and across the interior thereof separably attached to said sheet and extending adjacent and across said sheet and beyond the edges thereof, and extraction means attached to said sheet for withdrawing said sheet from said deployment bag.

8. A fabric retainer in accordance with claim 7 in 6 which said flexible sheet has a plurality of loops along edges thereof, said lines passing through said loops.

9. A fabric retainer in accordance with claim 8 in which said extraction means comprises a flexible strap attached at one end to said flexible sheet.

10. A deployment bag according to claim 3, in which said fiap comprises two substantially overlying sheets of flexible material, said spring biased stiffening means being positioned between said sheets and biased to spread said sheets apart at said opening edge upon release of said flap.

11. A deployment bag according to claim 3, in which said releasing means comprises a riser connected along the length of said deployment bag by a plurality of breakties adapted to break away from said bag upon ejection of said bag and straps connected to said riser at one end and to break-ties securing said flap on said deployment bag at their other end and adapted to break said break-ties retaining said flap to said bag upon the breaking away of said riser.

12. A deployment bag according to claim 3, in which said flap comprises a pair of substantially overlying flexible sheets joined together at their sides and at the end thereof remote from said opening edge, said spring biased stiffening means being positioned between said sheets and having stiffening portions thereof attached to each of said sheets and adapted to spread said sheets apart at said opening edge upon release of said flap.

13. A deployment bag according to claim 3, in which a break-line connects said parachute to said flap.

14. The method of packing a parachute in a bag having holes therethrough to the space for said parachute comprising:

(a) folding said parachute within said bag,

(b) placing over said parachute and in said bag a fabric retainer having separable lines extending therefrom,

(c) threading said lines through said holes to the exterior of said bag,

(d) compressing said parachute and said fabric retainer into the space for said parachute,

(e) tensioning said lines to retain said parachute within said space,

(f) releasing said compression,

(g) closing said space over said fabric retainer,

(h) removing said lines through said holes, and

-(i) removing said fabric retainer without reopening said closed space.

15. In the method according to claim 14, said fabric retainer is removed by drawing out said fabric retainer between closure flaps and an inside wall of said bag.

16. In the method according to claim 14, compressing said parachute within said space prior to placing said fabric retainer over said parachute.

References Cited UNITED STATES PATENTS 1,603,648 10/1926 Thornblad 244-148 1,909,158 5/1933 Albihn 244-447 2,316,895 4/ 1943 Smith 244148 2,702,679 2/1955 Culver 244148 X 3,145,956 8/1964 Widdows 244-147 FOREIGN PATENTS 1,081,945 6/ 1954 France.

MILTON BUCHLER, Primary Examiner.

R. A. DORNON, Assistant Examiner.

US. Cl. X.R. 53124; 267-1