Stowable Air Scoop

Abstract

A foldable ram air scoop for gathering and channeling external air into a condary thrust chamber, or afterburner, of an air-augmented thrust propelled missile is provided. The scoop is deployable prior to launch, being foldable against the missile body while stowed within a volume restricted storage magazine. The present air scoop essentially comprises a two-stage folding mechanism which compactly holds the scoop body against the missile, controllably deploys the scoop to a desired configuration, and positively locks the scoop in the proper position.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

Air capture and ducting mechanisms for supplying external air to a ramjet engine have previously been used. Generally, the air supplied from the environment of the vehicle being propelled by the ramjet engine burns with fuel in a combustion chamber used previously as a fuel chamber for booster burn. The air scoop itself must be large enough to accommodate a desired volume of air, yet must have sufficient structural integrity to withstand the high loading imposed on the relatively non-aerodynamic projection extending from the aerodynamic body surface of the vehicle. Often it is required that these air-breathing missiles be packaged within and often launched from a volume restricted chamber. Presently, thrust augmentation development is primarily directed toward achievement of greater thrust per unit of either launcher volume, magazine storage volume, or both. An integral rocket-ramjet vehicle which necessitates the intake of large quantities of air for internal combustion provides one solution to the present problem. Although useful in other applications and missile configurations, the invention is conveniently applied to the integral rocket-ramjet vehicle. This vehicle is launched and accelerated by a solid fuel booster having a fuel chamber which, after burnout and some parts jettison, becomes a combustion chamber for fuel supplied from a liquid fuel chamber. Air scoops structured according to the present invention are disposed on the external surface of the vehicle body substantially along that portion covering the liquid fuel chamber. In order to be stowable within a volume restricted storage magazine, the air scoops must be retractable against and/or within the vehicle body. On exit from the storage magazine and prior to launch, the air scoops are deployed in a desired configuration and, after solid fuel burnout, gather and channel external air through ducts communicating into the chamber which now functions as a combustion chamber. Therefore, the principal object of the present invention is to provide a foldable air scoop which is readily deployable from a retracted position to an optimum extended position and which, on assumption of such extended position, positively locks in place.

Use of the present air scoop mechanism is not limited to the integral rocket-ramjet briefly described above. For example, an air-augmented afterburning combustion engine may conveniently employ the invention to introduce externally-gathered oxidizing air into a secondary combustion chamber for more complete oxidation of fuel-rich exhaust gases exiting a primary combustion chamber. In such instance, the fuel-rich, partially unoxidized gases entering the secondary combustion, or afterburning, chamber are oxidized by the air and subsequently ejected from the secondary combustion chamber with increased specific impulse. In general, the invention is useful in any known situation requiring external gathering and channeling of air into a connection chamber for oxidative reaction therein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of an integral rocket-ramjet missile employing the foldable air scoop mechanism of the present invention, said mechanism being shown extended;

FIG. 2 is an exploded perspective, in partial section, of the air scoop and associated structure within the missile body;

FIG. 2a is an enlarged detail side elevation of the stop mechanism for the scoop body employed;

FIG. 2b is an enlarged detail perspective, partly in section, showing one of the locking elements for the scoop body, together with its associated spring and groove;

FIG. 3 is an enlarged detail section of a portion of the integral rocket-ramjet missile and showing the air scoop in its stowed configuration;

FIG. 4 is a view similar to FIG. 3 but showing the scoop in erected flight configuration;

FIG. 5 is a detail perspective of the locking mechanism for securing the scoop in extended position;

FIG. 6 is a top plan view of the ramp employed;

FIG. 7 is a side elevation of the ramp shown in FIG. 6; and

FIG. 8 is a transverse section on the line 8--8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is best described in an operative environment aboard a particular missile with which the invention has utility. Such a missile is shown generally at 10 in FIG. 1. The missile 10 is an airbreathing two-stage vehicle, launched and accelerated by an integral solid booster section 12, having a fuel chamber 14 which, on solid fuel burnout, becomes a combustion chamber for sustained ramjet flight. A liquid fuel chamber 16 disposed immediately forward of the chamber 14 provides fuel for ramjet flight, while air scoops 18 constructed according to the present invention capture external air and direct said air into the chamber 14 for combustion of the incoming liquid fuel.

The particular advantage of the present air scoops 18 derives from the necessity of folding said scoops into a low-profile storage configuration. Often, missiles are stowed prior to launch in storage magazines offering limited volume. In order to stow the missile 10 within the most efficient storage volume, external missile appendages, such as fins and said air scoops, must be made to be retractable against the body of the missile. Thus, when the missile 10 is removed from a storage magazine and while it is being readied for launch, the air scoops 18 are deployed in flight positions, in a manner to be described hereinafter. If the missile is not launched and is to be re-stored, the air scoops 18 are retracted to their stowed positions.

Referring to FIGS. 1 and 2, the several component parts of each scoop 18 are shown. The missile 10 is seen to be fitted with two of the scoops 18, one each on diametrically opposite sides of said missile and on the missile body substantially between the chambers 14 and 16. Each scoop 18 mainly comprises a leading edge element 22, a scoop body 24, and a ramp 26, these components being shown in an exploded view in FIG. 2 so that the scoop may be more easily described and understood. The leading edge element 22 is hinged to the scoop body 24 by a hinge pin 28. This hinged assembly substantially overlies an air inlet 30 which is defined by a missile body extension 32, a stationary inlet wall 34, a blowout door 36, and portions of the body of the missile. The leading edge element 22 consists of an essentially rectangular plate 38 which tapers in thickness to an edge 39.

Guides 40 extend angularly downwardly from the rear of the plate 38 at each side thereof and, when the scoop is in the stowed position, fit into sheaths 42 formed in the body of the missile 10 on either side of and immediately below the inlet wall 34. The guides 40 each have a camming surface 44 of rounded contour which communicates with an open ended slot 46. The guides 40 terminate in pointed end portions 48 which, at full scoop deployment, extend partially into the sheaths 42.

Referring also to FIG. 3, the ramp 26 is connected by a hinge pin 50 to a top wall 52 of the fuel chamber 16 and is shaped to maximize fuel storage volume. The ramp 26 consists of a forward portion 54 which is relatively gently inclined upwardly and a rear portion 56 which is inclined relatively sharply downwardly, the portions 54 and 56 merging at 55. As best seen in FIGS. 2, 4 and 7, the under side of the rear portion 56 of the ramp 26 is provided with a stop 57 which has a groove 58 and a lip 59, the stop 57 extending laterally a short distance beyond the side walls of the ramp 26. A leaf spring 60, fastened to the under side of the ramp 26, bears against the top wall 52 to bias said ramp upwardly when externally applied forces which tend to hold the ramp down are lessened. In the stowed position shown in FIG. 3, the front surface portion 54 of the ramp 26 is seen to lie substantially parallel to the body of the missile 10.

The scoop body 24, shown best in FIG. 2, performs the major portion of the air-gathering function of the air scoop 18. The body 24 consists of an inverted U-shape, rectangular body plate 62 having two side members 63, the body acting as an air-collecting chamber. The side members 63 gradually increase in height from the hinged connection of the body 24 with the leading edge element 22, and at such an angle that the upper edges of the guides 40 of the element 22 will fit flush against the lower edges of said members. The side members 63 are cut away at 64 and terminate in tapered edge portions 65. Formed in each of the side members 63 near its outer end is an opening 66. The scoop body 24 lies substantially parallel to the missile 10 when the scoop 18 is in the retracted, or stowed, configuration shown in FIG. 3. In the flight configuration, shown in FIG. 4, the scoop body 24 is angularly disposed to the missile 10, the sliding edge portions 65 of the side members 63 engaging the body of the missile.

As can be seen in FIGS. 2b, 4, and 5, the scoop body 24 is slidable in external tracks 68 which have open longitudinal grooves 69 in the opposite walls thereof. Each groove 69 terminates at its forward end in a circular locking port 70 of a diameter greater than the width of said groove, said port 70 extending through said track. Spring-loaded locking discs 71 are received within the circular locking ports 70, as will be explained hereinbelow. The disc 71 has a circular base 72 and a raised generally rectangular locking element 73 thereon. The locking element 73 extends diametrically of the base and is formed with a slot 74 in which is secured the forward end of a leaf spring 75. As best seen in FIG. 5, the rear end portion of the spring 75 bears against the upper wall of the groove 69. The base 72 of each locking disc 71 fits into one of the openings 66 on each side of the scoop body 24. The locking elements 73 extend from the base 72 and slide in the grooves 69 in the external tracks 68. The scoop body 24 is thus mounted for sliding movement along a fixed path. Movement of the body 24 to a forward, erect position, such as is shown in FIG. 4, causes the locking elements 73 of the discs 71 to exit the grooves 69 and extend into the circular locking ports 70. The locking discs 71 are caused to rock on release of the locking elements from the grooves 69, by the action of the springs 75, to such positions that said locking elements will be mis-aligned with respect to the grooves. Thus, the discs and locking elements prevent the scoop body 24 from sliding aft to its retracted configuration.

In FIG. 3, the air scoop 18 is seen in a low-profile, retracted position. The leading edge element 22, scoop body 24, and ramp 26 are seen to lie substantially parallel to and against the body of the missile 10. The ramp 26 is held downwardly by the camming action of the forward portions of the guides 40. The guides 40 of the edge element 22 are substantially received within the sheaths 42. The scoop body 24 lies substantially flat against the missile, the locking elements 73 of the locking discs 71 engaging the grooves 69 of the tracks 68 at the points of greatest distance from the circular locking ports 70, i.e., near the outer ends of the grooves.

Erection of each of the air scoop 18 is achieved by an actuator (not shown), such as a pneumatic jack located on the body of the missile. The actuator exerts force on the aft end of the scoop body 24 to move the scoop 18 into the deployed configuration shown in FIG. 4. Deployment of the scoop 18 substantially involves sliding the scoop body 24 forwardly, the sliding edge portions 65 of the side members 63 slidably engaging the body surface of the missile 10. Force is thereby exerted on the leading edge element 22. The scoop body 24 is forced outwardly from the missile body by the camming action of the guides 40 on a rolled portion 76 located on the stop 57 on the ramp 26. The locking discs 71 in the openings 66 in the scoop body 24 rotate to allow said body to move forwardly and outwardly and maintain sliding alignment of the locking elements 73 of said discs 71 within the grooves 69 in the tracks 68. As the scoop body 24 slides forwardly and outwardly, the leading edge element 22 also moves forwardly and outwardly as the guides 40 are drawn from the sheaths 42. However, due to the angle at which the sheaths 42 are disposed in the body of the missile, the body plate 62 of the leading edge element 22 maintains substantially parallel alignment with the missile body by partially rotating on the hinge pin 28. Continuing forward movement of the scoop body 24 eventually brings the rear edges of the guides 40 into contact with said scoop body, thus forming continuous side walls for the air scoop 18.

As the scoop body 24 reaches the point of maximum forward displacement, the camming surfaces 44 on the guides 40 allow the ramp 26 to be biased outwardly by the spring 60. As the ramp 26 moves outwardly about the hinge pin 50, the guides 40 engage the stop 57 with the rolled portion 76 in the slots 46. The interconnection between the ramp 26 and the guides 40 of the leading edge element 22 provides, along with the locking discs 71 which lock into the circular locking ports 70 substantially simultaneously with the occurrence of the interlocking just described, positive locking of the air scoop 18 in an erect, air scooping position. In this erect position, the rear portion 56 of the ramp 26 is seen to align with the inlet wall 34 .

Claims

I claim:

1. In an aerial vehicle having a combustion chamber, an air scoop comprising;

an inlet wall,

a movable ramp mounted to cooperate with the inlet wall,

a scoop body,

means slidably connecting the scoop body to the vehicle,

said air scoop being movable from an inoperative position lying adjacent the vehicle to an operative position extending from the vehicle,

said scoop body, said ramp and said inlet wall cooperating to define an air inlet for directing air into the combustion chamber when the scoop is in operative position, and

means for locking the scoop in extended position.

2. The invention recited in claim 1 and further including a blowout door at the inner end of the inlet wall.

3. The invention recited in claim 1,

including additionally a leading edge element hingedly connected to the scoop body.

4. The invention as recited in claim 1,

wherein the means for slidably connecting the scoop body with the vehicle comprises sheaths formed in the vehicle body at each side of the inlet wall,

and guides on the scoop body and slidable in the sheaths.

5. The invention as recited in claim 4,

including means for engaging the ramp for moving the ramp into alignment with the inlet wall as the scoop is moved to operative position.

6. The invention as recited in claim 5,

wherein said ramp moving means includes a groove on the rear end of the ramp, said groove defining a rolled portion and a lip, and an open ended slot in each of the guides near its rear end, said slots receiving said rolled portion therein.

7. The invention as recited in claim 1,

wherein the scoop body comprises a leading edge element and a body plate hingedly connected to the leading edge element,

said scoop body lying with a portion of said leading edge element in engagement with said ramp when the scoop is in inoperative position, thus providing a smooth aerodynamic surface for said scoop.

8. The invention as recited in claim 1,

wherein the locking means comprises tracks on the vehicle and having grooves terminating at corresponding forward ends in locking ports,

locking elements carried by the scoop and having portions movable from the grooves into the locking ports,

and springs on the elements and cooperating with a wall of each of the grooves for moving said elements out of alignment with said grooves, whereby said scoop will be prevented from moving into inoperative position.

9. The invention as recited in claim 1,

wherein the locking means comprises tracks on the vehicle and having said grooves terminating at corresponding forward ends in locking ports,

side members on the scoop body and having openings,

locking discs in the openings and having locking elements extending into the grooves,

and springs on the locking elements,

said locking elements being slidably from the grooves into the locking ports when the scoop is moved fully forward and outward,

said springs cooperating with corresponding walls of the grooves for moving the elements out of alignment with said grooves.

10. The invention as recited in claim 5,

wherein the ramp engaging means comprises a spring on the vehicle and engaging said ramp.