US2949267A

US2949267A - Fast-acting parachutes

Info

Publication number: US2949267A
Application number: US718361A
Authority: US
Inventors: Fred B Stencel
Original assignee: AMCEL PROPULSION Inc
Current assignee: AMCEL PROPULSION Inc
Priority date: 1958-02-28
Filing date: 1958-02-28
Publication date: 1960-08-16
Anticipated expiration: 1977-08-16

Description

Aug. 16, 1960 Filed Feb. 28, 1958 F. B. STENCEL FAST-ACTING PARACHUTES 3 Sheets-Sheet 1 INVENTOR FRED B. STENCEL,

ATTORNEY Aug. 16, 1960 F. B. STENCEL 2,949,267

FAST-ACTING PARACHUTES Filed Feb. 28, 1958 3 Sheets-Sheet 3 .8 2. Hum/U]! INVENT OR FRED B. STENCEL ATTORNEY FAST-ACTING. PARACHUTES Fred B. Stencel, Asheville, N. (1., assignor to Amcel Propulsion, Inc.

Filed Feb--28, 1958, Ser.No.:718,-361

'3 Claims. (Cl. 244-447) This invention relates-to power'projected, fast-acting parachutes and is particularly applicable to explosively projected and deployed parachutes of the generaltype disclosed and claimed in my copenclingapplication Serial Number 581,535, filed April 30, 1956.

Parachutes of the type referred, totcompris'eiboth a power projection means and a projected"assembly,"tlie' latter includniga specially foldedparachute canopy, power deployment .means connected to! the'canopy to deploy the same, and means for actuatingjthe'deployment means at theiproper pointiinthe proje'otedfiight': of'the assembly. Advantageously, the" overall combine!- tion is constructed in the manner disclosedLin' my pending applicationSerial Number 718,362} both the projectionmeans and the deployment means beingex plosively operated, and the actuating means employed to set'oflithe deployment means is made responsive to' (16 celerationof the projected assembly in the mannerdis closed in my copending. application Serial Number 718,349.

Such parachutes must be .very fast inaction, with'the total.time required for projection andideployment being less than one second, for example; Such'fast action is attained only with the use of a relatively powerful explosive deployment charge. Hence, itis particularly important to provide some highly reliable means for pre venting the explosive deployment" charge from being ig-, -v nited accide'ntly.

The general object of thepresent invention is'to provide; in combination with a parachute construction ofthetype described,'a novel and effective safety means. soconstructed and arranged as to preclude operation of the. explosive means untilthe projected assembly of theiparachute is in flight.

A further object is to devise such safety means whichisjde activated only upon separation of the projected. assembly from the projection means In order that the manner in which. these and other obje'cts are attained in accordance with the invention can be understood in. detail, reference. is had toltheaccompanying drawings,.which forma partofthisspecification; andwhereim Fig. 1 is a vertical sectionallview, with some parts showninnelevationuand others broken. away for clarity; of, a parachute in accordancewith one embodimentxof the invention;

Fig. .2, is a detail vertical .-.sectional view of sthe -deployment meansaof the-apparatus :Off Fig. ,1, showing .thesamesinunactuated condition;

Fig.3 is a viewrlike-.'Fig.- 2, but showingithe-deploy? ments immediately after actuation thereof, and

Fig; 4 a transverse: sectional. view taken onaline 4-4 Fig. '1.

As i seen inn-Fig. .1, thisqembodiment :of the inventions combines a projected assembly indicated generallyatn-l 70 and=a mounting-and projectingassembly indicated-genorally at 2.' Projected assembly 1 comprises a pro- 2,94 ,257 Patented Aug." 16, 1960 jctile or supporting tube 3, canopy deploying means 4; the inertia-operated actuator for the deployment A means," indicated at 5; the specially folded canopy 6 and the canopy"retaining'bag 7. The mounting and projecting assembly is constructed in accordance with my copending application Serial Number 718,364, filed con.-

currently herewith, and cor'nprises' aprojecting-tube 8 secured to a transversely extending mounting plate 9, bywhich the parachute is mounted on any. suitable sup porting structure before projection and deployment. Disposed within projecting tube 8 is a tubular combustion chamber 10' containing an explosive projection charge 11.

A filing pin actuator unit 12is operatively associatedwith charge 11 and adapted to be triggered by a Bowden wire -13, as fully explained in the aforementioned copending application.

The projectile or supporting tube 3 of theprojected assembly [telescopically embraces the projecting-tube-8.

The combustion chamber 10 is perforated, as indicated at 14, so that the explosion gases generated by charge "11 escape through the perforations 1 4 into the tube 8- and" are effective to act against means closing-the upper end of tube 3," so that theassembly 1 is projected away fromthe-mounting and projecting assembly When charge ll is' ignited in response to operation of Bowden wire 13. Advantageously, the lower 'end portion of tube 3 is provided with a transverse internal groove in which is disposed a sealing ring 15 "to accomplish asubstantially fluid tight-seal between tubes 3 and 8.

The canopy 6 is folded in accordance with my co-" pendingap'plication Serial-Number 581,764, filed'April 30, 1956, and comprises a stacked seriesof generally? toroidal folds 6, tube 3 extending through thecenters oflthelfoldso The canopy'is disposed with'its periphery adjacent the deployment means 4 and-with itsapex dis' posed'considerably-therebelow and attached to tube *3. Attachment ofthe-apex of the canopy to tube -3 may be accomplished'in any suitable fashion, the-meansde'scribed' in my copending application Serial Number 718,362; filed concurrently herewith, being particularly advantageousi.

Deployment means 4 is constructed in accordance with" my-copending' application Serial Number 718,363; filed concurrently herewith, andcomprises a main body-16 havingca centrally disposed, upwardly opening deployment charge chamber '17. Body plurality of radially directed-bores 18, and suitable conis provided with two radially spaced, concentric, dependent flanges-22 having radially-aligned openings. Each projectile 2i? includes a pin 23 disposed in one such opening-When the'projectile stem 'is inserted to its bore 18. At its top, the body- 16is provided with a peripheral flange 24 having radially directed *openings equal in number tto-the-bores 18. Each deployment projectile is equipped with a pin 25 extending through one of such" openings in the upper flange 24. A single, circularly extending shear wire 26 runs through transverse bores in all of the upper pins '25, to retain' theprojectiles 20" in their initial position. I

Within-charge-chamber17, there is-mountedan explosivecharge 27 havinga primer operatively disposed With respect to-a firing'pin 28 centrally'located in body 16. The charge =27 is retained in place by a cap-screw 29,

threaded downwardly'into chamber 17.

Each suspension line 30 of-the parachute extends'frcm 16 is provided with a the main body portion 31 of one of the projectiles 20. The projectile is secured with respect to the suspension line in any suitable fashion, as by means of a loop of cord or fabric 32 extending through the main body 31, along with. the suspension line, and having its ends attached either to the suspension line or to the periphery of the canopy. From the projectiles 20, the suspension lines extend downwardly, are grouped together into two bundles, and each bundle is stowed in a different one of two series of pockets in a line storage sleeve (not shown) which has an open top and is secured to the mounting means from which the parachute is projected.

The canopy bag 7 is made up of a lower portion 35 and an upper portion 36connected by lacing. Upper portion 36 consists of a plurality of. upwardly extending tapes 37 so connected at their lower ends as to be in sidewise overlapping relationship. At its top, each tape 37 has attached thereto a loop 38 of cord or the like extending upwardly to the deployment means. Each of the projectile pins 23 extends through a different one of the loops 38. Thus, the combination of pins 23 and loops 38 maintains the expansible top mouth of the upper bag portion 36 closed prior to deployment of the parachute canopy.

The parachute is equipped with four arresting lines 39, each having one end attached to the canopy bag at the bottom of lower bag portion 35. From their points of attachment to the canopy bag, the arresting lines extend upwardly between the canopy bag and line storing sleeve (not shown) and are separated into two pairs, each pair of arresting lines being joined with one of the two bundles of suspension lines and thus also stowed, along with the suspension lines, in the pockets of the sleeve, as fully described in the aforementioned application Serial Number 718,362. Where they emerge from the last of the pockets in the storing sleeve, the suspension lines and the arresting lines of each bundle are all attached to a different one of two buckles 40. Also attached to the buckles 40 are two riser extension straps, not shown, which extend to, and are attached to, the body or load to be recovery by the parachute during operation thereof.

Thus, the arresting lines have one end attached to the load to be recovered and the other end attached to.

the lower portion of the canopy bag, it being understood that the canopy bag is a part of the projected assembly. All of the suspension lines similarly have one end attached to the periphery of the parachute canopy and connected to the deployment projectiles. The arresting lines are made effectively shorter than the suspension lines. That is, the length of the arresting line plus the distance between the point of attachment thereof to the canopy bag and the deployment means is materially shorter than the length of the suspension line extending from the deployment means to the buckle 40. It will thus be understood that, when the parachute is projected as a result of explosion of the projection charge 11, the suspension and arresting lines then paying out of their storage pockets, the arresting lines will become taut at a time when the suspension lines are still slack.

At its bottom, and concentrically inwardly of lower flange 22, the body 16 includes a dependent flange 41 defining a cavity 42 in the top wall of which is provided the firing pin retaining bore 43. The firing pin 28 includes an annular transverse shoulder 44 slidably engaging the cylindrical wall of bore 43, the firing pin being retained in the bore by a snap ring 45 located beneath shoulder 44. The primer-engaging head 46 of the firing pin extends through a smaller bore 47 communicating with the cavity in which charge 27 is mounted.

The outer surface of dependent flange 41 is provided with screw threads engaged by matching, internal threads on the upper end portion of a cup-shaped housing 48. Housing 48 has a transversely extending bottom wall 49 disposed across and in contact with the upper end of projectile tube 3. At its center, bottom wall 49 of the housing is provided with a dependent, cylindrical extension disposed within the upper end portion of tube 3 and aligned co-axially with that tube, the bottom of extension 50 being closed by a wall as indicated at 51. Thus, the extension 50 defines a cylindrical chamber opening upwardly into the interior of housing 48.

Mounted within extension 50 is a cylindrical bushing 52 having, at its upper end, a shoulder 53 engaged over the top surface of bottom wall 49 of housing 48. Slidably disposed within bushing 52 is the lower shank portion 5 5 of a firing pin actuating plunger 55. The plunger includes an upper striking head 56 aligned with firing pin 28. Between

portions

54 and 56, the plunger 55 includes an outwardly directed annular shoulder 57 disposed above the top shoulder 53 of bushing 52.

The firing pin actuating plunger 55 is arranged to actuate the firing pin in response to deceleration of the projected parachute, but is initially biased to an inactive position by a plurality of radially disposed compression springs 58. Each spring 58 is enclosed within a telescopically engaged pair of

tubes

59, 66. Each smaller tube 59 has its outer end pivoted on a pin 61 extending through suitably spaced, vertically extending flanges 62. The flanges 62 are made integral with and depend from an annular plate 63 clamped between the top of housing 48 and the bottom of flange 41 of deployment body 16.

At their ends adjacent the plunger 55, the larger tubes are each provided with a bifurcated portion embracing a radially directed boss 65 on plunger 55 above shoulder 57 and pivoted to such boss by a pin 66. Thus, the combination of tubes 59 and 60 constitutes means for enclosing the springs 58 and maintaining the same in radial positions with respect to the plunger 55.

The vertical spacing between the bottom of shoulder 57 and pins 66 is such that, when shoulder 57 is engaged with the bushing 52, pins 66 are disposed in a transverse plane located below that plane in which pivot pins 61 are located. See Fig. 2. Springs 58 always being maintained in compression by the telescopic tubes 59 and 60, the springs are efiective to bias the plunger 55 into the position just mentioned. However, when the arresting lines 39 become taut during the projected flight of the parachute assembly, the projected assembly is abruptly decelerated. This deceleration causes actuating plunger 55 to move upwardly, against the biasing force of springs 58. When the deceleration is of a pro-selected value, the force with which plunger 55 moves upwardly is sufficient to compress springs 58 to an extent such that pins 66 are brought just above pins 61. When this occurs, the springs 58 are no longer effective to bias the plunger away from the firing pin, and the plunger accordingly snaps upwardly into engagement with the firing pin and so explodes the primer for deployment charge 27. See Fig. 3. As a result of explosion of charge 27, the deployment projectiles 21 are thrown radially outward, substantially instantaneously deploying the canopy 6 in the manner fully described in the aforesaid copending application Serial Number 718,362.

At a point within bushing 52, the plunger 55 is provided with an outwardly directed, transverse notch or groove 67. Laterally aligned with this groove is a bore 68 in bottom wall 49 of housing 48. A slidable latch pin is disposed in bore 68 and provided with a transverse shoulder 70, a compression spring 71 being positioned between shoulder and the inner end of bore 68, so as to urge the latch pin radially outward. Communicating with bore 68 is a downwardly extending bore 72 in which is engaged, prior to projection of the parachute, the upper end portion of a latch rod 73. Thus, the upper end of latch rod 73 is engageable with the outer surface of shoulder 70, so holding the latch pin 69 in an inward position, with the inner tip of pin 69 engaged in notch or groove 67 and preventing upward movement of plunger 55.

Latch rod 73 extends downwardly beside tube 3, thus 8 through the central space defined by the canopy folds 6 and through a suitable opening in mounting plate 9. Secured to the lower surface of mounting plate 9 is a latch plate 74 having a key slot 75 therein, as seen in Fig. 4. At its bottom end, the latch rod 73 is provided with an enlarge tip 73 having a peripheral notch or groove 76. The edge portions of plate 74 which define slot 75 are engaged in notch or groove 76, so that the latch rod is retained by the mounting means when the parachute assembly is projected. Thus, upon projection of the parachute, the upper end of the latch rod is necessarily withdrawn from its bore 72, so that spring 71 then forces latch pin 69 outwardly, disengaging the inner up thereof from notch or groove 67 and leaving the plunger 55.free for upward movement when the projected assembly is caused to decelerate by tautening of the arresting lines at the end of the projected flight. Advantageously, a shear pin 77 extends through the upper end portion of latch rod 73 into the material of housing 48 which defines bore 72, shear pin 77 being ruptured as a result of projection of the parachute assembly.

It will be noted that rod 73 lies close beside tube 3 and that the full extent of the rod above mounting plate 9 is smooth, without lateral projections. Thus, the presence of rod 73 within the central space defined by the series of annular canopy folds 6 in no way impedes the projection of the parachute, once shear pin 77 is broken.

I claim:

1. In a fast-acting parachute, the combination of a projected assembly comprising an elongated support member, a parachute canopy disposed in a series of annular folds surrounding said support member, deployment means mounted on said support member and operatively connected to said canopy to deploy the same, and inertia-operated actuating means operatively associated with said deployment means, said actuating means including a safety latch movable between latching and nonlatching positions and resiliently biased to its non-latching position; a mounting and projection assembly operatively associated with said projected assembly to project the same; a latch retainer secured to said mounting and projection assembly and releasably engaged with said safety latch to retain the same in its latching position until said projected assembly is projected away from said mounting and projection assembly; and arresting line means connected to said projected assembly to decelerate 6 the same, at a given point in its projected flight, to cause said actuating means to actuate said deployment means.

2. In a fast-acting parachute, the combination of a projected assembly comprising an elongated support member having leading and trailing end portions, deployment means mounted on said member at the leading end portion thereof, a parachute canopy disposed in a series of annular folds generally concentric with said member, the periphery of said canopy being disposed adjacent said deployment means and the apex thereof being disposed at a point spaced along the support member from the deployment means, said deployment means being operatively associated with said canopy to deploy the same, inertia-operated actuating means operatively associated with said deployment means, said actuating means including a safety latch movable between latching and non-latching positions and resilient means connected to said latch and biasing the same to its non-latching position; a mounting and projection assembly comprising fixed mounting means, a projection tube secured to said mounting member and telescopically engaged with the support member of said projected assembly, and power means for projecting said support member from said tube; a latch retainer secured to said mounting means and extending along beside said suppo'rt member within the annular folds of said canopy, said latch retainer releasably engaging said safety latch and holding the same in its latched postion until said support member is projected from said tube; and arresting line means connected to said projected assembly to decelerate the same, at a given point in its projected flight, to cause said actuating means to actuate said deployment means.

3. A parachute in accordance with claim 2 and wherein said actuating means comprises a plunger mounted for movement longitudinally with respect to said support member, said latch comprises a member movable radially of said plunger and engageable therewith to prevent such longitudinal movement, and said latch retainer is a rod having its tip engaged with a surface of said latch member directed radially away from said plunger.

Austria June 26, 1933 France Jan. 25, 1912