Fast-acting parachutes

Dec. 20, 1960

2,965,337

F. B. STENGEL

FAST-ACTING PARACHUTES

Sheets-Sheet 1

Filed Feb, 28, 1958

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BY

ATTORNEY

F. B. STENGEL

FAST-ACTING PARACHUTES

Dec. 20, 1960

Filed Feb. 28, 1958

2,965,337

Sheets-Sheet 2

<img file="US2965337A_D0002.tif" />

ATTORNEY

Dec. 20, 1960

2,965,337

F. B. STENCEL

FAST-ACTING PARACHUTES

<img file="US2965337A_D0003.tif" />

ATTORNEY

United States PatentOffice „ 2,955.337

Patented Dec. 20, 19S0 ' ^?·/1 .· . 2

Tube 3 telescopically embraces the projecting tube 6 of the projecting assembly 2. The lower end of tube 3 abuts o« tT7 the upper surface of a flange 7 which forms a part of tube

2,965,337 6 and is located on the lower or trailing end portion thereFAST-ACTING PARACHUTE^ , . ⁵ of. The tower etid portion of tube 3 is provided with a π J » ex . . . . , transverse internal groove 8 in which is disposed an O-ring

Fred B. Stencel, Asheville; N.C;, assignor to Amcel Pro- 9 to provide a substantially fluid-tight seal between tubes pulsion Inc., a corporation of Delaware 3 _an(j g

Filed Feb. 28, 1958, Ser. No. 718,364

Claims. (Cl. 244—147)

This invention relates to fast-acting parachutes and is 15 especially applicable to parachutes of the type disclosed in my co-pending application Serial Number 581,535, filed April 30, 1956.

The general object of the invention is to provide, in combination with a fast-acting, power-projected para- 20 chute, a novel and effective projecting means so constructed as to project the projected assembly in a predetermined direction at a high rate of speed, so that the total projected flight time is as short as 0.3 second.

A further object is to devise a simple and effective ex- 25 plosive projection means, for parachutes of the type referred to, including novel means for confining the explosion gases during the initial movement of the projected assembly in such fashion as to make more effective use of the explosive means employed. 30

Another object is to provide, in such a projection means, a novel arrangement for assuring a sudden, rather than relatively gradual, release of the explosion gases.

’ Yet another object is to provide projection: means including a projection tube, an explosive charge situated 35 within the tube, and an actuating assembly for the explosive charge, with the actuating assembly mounted on the end of the tube adjacent the charge and closing such end of the tube in a novel fashion.

A still further object is to: provide, in such apparatus, 40 actuating means for the explosive charge, which actuating means includes a triggering device which also acts as a safety latch, such device being necessarily placed in “safe” position before arming.

: Another object is to provide in such a projection assem- 45 bly an actuating means which can be completely assembled with the triggering device in “safe” position, before being mounted in its operative position with respect to the explosive charge which it is to actuate. :

. In order that the manner in which these and other ob- 50 jects are attained in accordance with the invention can be understood in detail, reference is had to the accompanying drawings, which form a part of this specification, and wherein: _: :

Fig. 1 is a vertical sectional view, with some parts 55 shown in elevation and others broken away for clarity, of a parachute in accordance with one embodiment of the invention;

Fig. 2 is a detailed vertical sectional view of the projecting means of the apparatus of Fig. 1, on enlarged scale 60 and showing the same in unfired condition, and

Fig. 3 is a view like Fig. 2 but illustrating the projecting : means in the fired condition.

As seen in Fig. 1, this embodiment of the invention comprises a projected assembly indicated generally at 1 and 65 a projecting assembly indicated generally at 2. The projected assembly 1 is constructed in accordance with my co-pending application Serial Number 718,362, filed concurrently herewith, and, comprises a projectile or supporting tube 3 with a canopy 4 specially folded around tube 3. 70 A deployment means 5 is mounted at the upper or leading end of tube 3 and serves to close off that end of the tube.

Projecting tube 6 is secured to the mounting structure indicated generally at 10. The mounting: structure 10 in turn is secured to any suitable supporting structure (not shown) before projection of the projected assembly, only the top wall 11 and side walls 12 of the mounting structure being shown in the drawings. In addition to mounting the projection means, structure 10 also serves to protect that portion of the projecting assembly 2 located below the top wall 11, as hereafter explained.

The lower end portion of projecting tube 6 passes through an opening provided in top wall 11 of mounting structure 10. The tower surface of flange 7 of tube 6 abuts a retaining plate 13 below which is disposed a spacer 14, the lower surface of spacer 14 being seated against the upper face of top wall 11. Tube 6 then passes through an opening in a latch plate 15 which is disposed adjacent and below top wall 11. The lower end portion of tube 6 is threaded so as to receive lock nut 16 which is brought into contact with the tower surface of plate 15 to retain the same in place. Projecting tube 6 is thus rigidly secured to mounting structure 10.

Positioned within projecting tube 6 is a combustion chamber 17. The outer diameter of the tower portion 18 of chamber 17 is the same as the inner diameter of tube 6. Combustion chamber 17 is provided with a bottom end flange 19, the upper surface of which abuts the tower end of tube 6. The combustion chamber 17 is generally in the form of a hollow cylinder, and has an upper portion 20 of smaller outer diameter than the tower portion 18. The upper portion 20 is closed at its free end and the wall of the upper portion is provided with a plurality of perforations 21.

An explosive charge container 22 with an outer diameter equal to the inner diameter of tower portion 18 of chamber 17 is positioned within the lower portion 18. Container 22 is provided with a base flange 23 which abuts the lower surface of end flange 19 of chamber 17. A deformable closure plate 24. serves to close the upper end of container 22, the peripheral portion of plate 24 engaging the upper end of the container. A rod 25 of small diameter, secured in any suitable fashion, to the closed upper end of chamber 17, is of such length as to have its tower end abutting the upper surface of plate 24, at the center thereof, when container 22 is in place within chamber 17. Rod 25 thus serves to hold plate 24 in position against the top of container 22. An explosive charge 26 is enclosed within container 22. Below charge 26, container 22 also mounts a primer 27 coaxially aligned with projecting tube 6, the tower end of primer 27 extending slightly below flange 23.

A firing pin assembly, indicated generally at 28, is positioned below primer 27 and container 22. The housing for the firing pin assembly 28 is a tubular member or sleeve 29 having an upper end flange 36 held in abutting relation with the lower surface of end flange 23 of container 22 by a cap nut 31 threaded to the tower end of projecting tube 6. Nut 31 has an inwardly directed flange 32 at its tower end which abuts the lower surface of end flange 30 of sleeve 29.

The upper end of sleeve 29 houses a firing pin 33 slidably disposed within a plug 34. A retaining screw 34^aholds plug 34 in place. The upper end of firing pin 33 is positioned within a bore 35 in plug 34 and aligned with the primer. The bore 35 is of increased diameter at

2,965,337 its lower end, so as to receive a flange 36 on firing pin 33. At the lower end of bore 35, plug 34 is provided with a transverse annular groove 37. With the firing pin positioned so that the flange 36 is disposed within the lower portion of bore 35 and above groove 37, a retain- 5 ing ring is placed within groove 37 and extends into bore 35 to prevent withdrawal of the firing pin. The length of the lower enlarged portion of bore 35 above groove 37 is greater than the width of flange 36 measured in the axial direction of member 29 by an amount sufficient to 10 allow movement of firing pin 33 into engagement with primer 27, the length of the portion of firing pin 33 above flange 36 being sufficient to enable the firing pin to contact primer 27 when the firing pin is suddenly urged upwardly. The portion of the firing pin 33 below flange 15 36 extends slightly below the end of plug 34 when the pin 33 is in its uppermost position.

Disposed within sleeve 29 and below the lower end of firing pin 33 is a firing pin actuating plunger 38. Plunger 38 has an upper portion of such diameter as to allow 20 free axial movement of the plunger within sleeve 29. The lower portion of the plunger 38 is of smaller diameter than the upper portion so as to form shoulder 39 and permit a spring 40 to be disposed between the lower portion of plunger 38 and the inner surface of sleeve 29. 25 The lower end portion of sleeve 29 is threaded to receive a cap nut 41, which nut has a hole 42 through its transverse wall to accommodate the lower end portion of plunger 38. Cap nut 41 thus provides a transverse shoulder against which one end of spring 40 engages. Spring 30 40 is therefore disposed between the transverse wall of cap nut 41 and the shoulder 39 of plunger 38.

The lower portion of sleeve 29 is provided With a radially directed aperture 43 through which the tip of a Bowden wire 44 extends. The Bowden wire 44 is brought 35 to the sleeve 29 via an Opening 46 in one of the Walls 12 of the mounting structure and adapter 45 mounted on sleeve 29 at aperture 43. The adapter 45, in addition to providing bore 47 to guide the tip of Bowden wire 44 to aperture 43, also serves as a means for securing the tip 40 of the sheath (not shown) of the Bowden wire 44.

The upper portion of plunger 38 is provided with a peripheral transverse groove 48. Prior to placing the spring 40 within member 29, the plunger 38 is so positioned that the groove 48 is aligned with aperture 43. _4gThe Bowden wire 44 is then inserted through aperture 43 and passes around and within a portion of groove 48. This positions plunger 38 relative to the lower end of sleeve 29 so that spring 40 will be compressed when placed within sleeve 29 and the cap nut 4 is threaded to _g0the lower end of sleeve 29. Bowden wire 44 is engaged within groove 48 sufficiently to prevent movement of plunger 38 by the force of spring 40. Groove 48 is employed, rather than using an aperture, in order to sim. plify the problem of properly positioning the plunger _ggwith respect to aperture 43 preparatory to insertion of the Bowden wire.

It Will be noted that the lower, end of projection tube 6, and the entire firing pin actuator assembly, are confined within a space defined by the top wall and side _6f)walls of the mounting structure 10.

Plate 13 serves as a means by which the lower end of a container in the form of a flexible outer bag 49 can be fixed to the mounting means for temporarily housing the projected assembly 1. The lower portion of bag 49 includes an opening whereby the lower edge Or bottom Of °⁵bag 49 is secured under a dependent flange, at the periphery of plate 13, as by a draw cord arrangement in the manner described in my aforementioned application Serial Number 718,362, so that the bottcm of the outer bag is γθ fixedly attached to the projection tube at a point above and adjacent the top wall 11. The upper edge of bag 49 is detachably secured to the dependent flange 50 of a cover plate 51 which is fixedly secured to the top of the projected assembly 1 by a cap screw 52. Consequently, 75 when the projected assembly 1 is projected, the lower end of bag 49 is retained by plate 13 and the upper end of bag 49 slips off flange 50 so that the bag is retained on the mounting structure.

Prior to operation, the projected assembly 1, projecting assembly 2 and mounting structure 10 are placed in assembled relation as shown in Figs. 1 and 2. Operation of the projecting assembly 2 is initiated by withdrawal of Bowden wire 44 from engagement with plunger 38. This allows the spring 40 to expand, moving the plunger rapidly into contact with the lower end of firing pin 33. The firing pin strikes the primer 27, which is thus ignited and which in turn ignites the charge 26 in container 22. The explosion gases produced force the deformable closure plate upwardly and around the lower tip of rod 25. The gases then pass into the upper portion of chamber 17 and thence through the perforations 21 and into tubes 3 and 6. Since projectile tube 3 is closed at its upper end by deployment means 5 and a substantially fluidtight seal is maintained between tubes 3 and 6 by the O-ring 9 at the lower end of tube 3, the expanding explosion gases force the projected assembly to travel away from the projecting assembly. Since the O-ring 9 is disposed at the lower end of tube 3, the seal is effective during the travel of the projected assembly 1 for that length of tube 6 determined by the spacing between the position j of O-ring 9 prior to actuation of the projecting assembly and the upper end of tube 6. The explosion gases are thus confined for a sufficient time period to bring the projected assembly 1 up to the desired speed.

The telescoping of tubes 3 and 6 imparts a predetermined direction to the travel of the projected assembly, which feature is important since, in many applications, it is necessary that the projected assembly be projected in a certain direction away from the object on which the assembly is mounted.

Deformable cover plate 24, with its associated rod 25, forms means operative to suddenly release the explosion gases from container 22 into the combustion chamber 17 at a time, subsequent to actual ignition of charge 26, when a predetermined amount of pressure has been built up with container 22. The extent of the time lag between ignition of the charge and release of the explosion gases into the combustion chamber is of course determined by the thickness of plate 24, the material from which it is fashioned, and the dimensions of the plate and the top of container 22.

It will be noted that the combination of Bowden wire 44 and the groove 48 in plunger 38 constitutes not only a triggering device for the firing pin actuating means, but also a safety device retaining plunger 38 against movement toward primer 27 under all conditions save removal of the Bowden wire from engagement with the groove 48. It is also to be noted that, if the device is armed after ? attachment of sleeve 29 to projection tube 6, spring 40 is not compressed, to store therein the energy necessary to actuate the firing pin, unless the tip of the Bowden z wire is first engaged in groove 48. Thus, the device is * conditioned to “safety” even before it is made operative to explode, the primer. Finally, it will be understood f’at the entire actuator assembly, including all parts carried by sleeve 29, can be assembled and readied for actuation before attachment to the projection tube 6, so affording additional assurance against accidental premature discharge of the projection means.