US2932238A - Airborne missile launcher - Google Patents

Description

A ril 12, 1960 D. D. MUSGRAVE 2 2,932,238

AIRBORNE MISSILE LAUNCHER I 2 Sheets-Sheet 1 Filed Jan. 10, 1958 w Mtbmt N .wmpsk Aprll 12, 1960 D. D. MUSGRAVE AIRBORNE MISSILE LAUNCHER 2 Sheets-Sheet 2 AIRSPEED Filed Jan. 10, 1958 T mSRFwME AIRSPEED m mmsmPx JNVENTOR.

; gun-type weapons.

i; lt is apparent that the tu 2,932,238 AIRBORNE MISSILE LAUNCHER Daniel D. Musgrave, Cabin John, Md. Application January 10, 1958, Serial No. 708,118

1 Claim. 01. sit-1.7)

invention relates to an airborne launcher for rockets, missiles, or similar devices. Wherever either the words rocke or missile is used hereinafter, it is not intended to be limiting, this being done merely to avoid repet'ition of the phrase rockets, missiles, or similar devices) The launcher'disclosed herein may be used to lauhch free ballistic rockets, guided missiles, or .any

other device having similar launching characteristics.

. \For offensive combattmilitary aircraft are sometimes equipped with launchers which release missiles in the "direction of flight. The defense of airplanes, however, is mostly a matter of protecting the tail, from which direction attack often comes. Tail-defenses using rockets or missiles have been devised, butwith ever increasing aircraft speeds, rearward launching may become erratic due .to technical difficulties. Guns have long been used for .ta'ihdefenseibut, their effective range has always been considered inadequate. 1

"When an object is projected from a moving platform in a direction opposite to that of the platform movement, "the velocity-of the platform is, of course, negative with respect to .that of the projectile. At some stage in this process the sum of the two velocities is zero. For conyeriience we may refer to this condition as zero airspeed. -.When ,agun-type weapon is fired rearwardly froma moving: aircraft this condition occurs while the projectile is;-passing through the barreland it causesno diificulty,

since the projectile completes its passage through the bore, T exits at its normal muzzle-velocity, and starts its trajectory Patented Apr. 12, 1960 primary object of this invention is to provide an airborne missile launcher, which will launch missiles rearwardly from a moving carrier, regardless of carrier velocity.

Another object is to provide a launcher with a stabilizing elementof variable length to meet varying conditions ;-of speed, altitude and tactics, and variations in the mis- 15' siles to be launched. 7

Another object is to providea launcher which will more fully exploit the capabilities of existing and future planeto-plane and plane-to-ground missiles. I

Still another object is to provide in a rearward launcher a means of disengaging the missile from mechanical stabilization when it is self-stabilized.

Other objects of the invention will be apparent from the description of the invention as hereinafter set forth in detail and from the drawings made a part thereof in which:

Figure l is a'sideelevation, partly sectioned, of the invention as applied to a missile launcher.

. Figure 2 is a cross-section on line 2-2 in Figure 1.

Figure 3 is a partly cutaway, perspective view of the turbine used to release the missile. t

Figure 4 is a perspective view of the button lug band used to suspend thefront end of the missile.

Figure 5 is a perspective viewof the front end of the stabilizer;

Figures 6, 7, 8, 9, and 10, are a schematic sequence of a possible launching technique, showing the successive positions of the carrier, missile, stabilizer and cable, at

H each stage in the process.

- Figure 11 is a graph, plotting travel against velocity forthe missile and'carrier as they appear in Figures 6 at a true velocity equal to muzzle-velocity minus plane speed. .With existing guns and aircraft this reduction doesnot affect projectile stability.

The initial acceleration of a typical missile is not as abrupt as the acceleration of bullets or shells fired from path for -a shorter time while it is acquiring velocity. In

In comparison with guns, missile Referring to Figure 1, there is shown a missile 1,

- ready for launching from a carrier structure 3, which might be an airfoil. Missile 1 is supported on a tubular stabilizer 5 which has an attached slide 41 in engagement with a guide 9 fixed to the carrier structure. Through the central bore of stabilizer 5 there passes a portion of a" flexible cable 11, to the end .of which is secured a drag kite 7, shown in a stowed position. The balance "of cablell is stored on reel 13. Having pointed out the the case of missiles fired by aircraft in the direction of flight this is unimportant, as the plane velocity is imparted to the missile and stability is easily attained. Missiles launched from aircraft are usually of the j fimstabilized type. Fin stabilization depends on the relative velocity of air passing the fins. When a fin-s'tabilized missile which has cleared its launcher approaches a con- ;dition of zero airspeed, it becomes aerodynamically unstable and tends to tumble. Not only is it useless against f the enemy .but it may 'even become a menace to the aircraft from which itwas released.

blin tendency will be even more pronounced when the missile approaches zero-airspeed while traveling tail-first, since the stabilizing fins,

which are intended to'act behind the center of gravity,

are moving ahead of it. Such a situation may be com v pared toan attempt by an archer to shoot an arrow with the feathered "end first. The arrow with the feathered end first would follow an erratic, unpredictable course.

similar situation could occur when a missile is launched at a target in" the rear of a fast aircraft. At the time major components of the launcher assembly we may now consider the details of construction.

Still referring to Figure 1 it may be noted that missile 1 is embraced near its forward end by a button lug band '27 which is shown in detail in Figure 4. Band 27 may be tightened at its split portion37 by bolt 35 and a suitable nut. To the upper part of band 27 is attached, as by welding,'a bracket 29 to which is welded a lug 31 terminating in a button, 33.

Button lug 31 is capable of engagement with a claw 45 which is shown in detail in Figure 5. Claw 45 is rigidly attached, as by welding, to stabilizer 5, at their area of contact 47. Also shown in Figure-5 is slide 41 which is secured to stabilizer 5 by fillet weld 43. The central bore 39 indicated in Figure 5 is capable of encompassing cable 11.

' Themissile is embraced near its rear by a turbine band 49 which is shown in detail in Figure 2. Band 49 has afiXed to its upper portion a bracket 51 and is capable of being tightened at its split portion 53, by bolt 55 and nut- 56. Through bracket 51 is formed a threaded hole 57, for suspending themissile. r

A turbine oranemometer 59, which appears in Figures 1, 2 and 3, suspends the rear of missile 1 from stabilizer 5. Turbine 59 is housed in casing 67 which is fixed to stabilizer by weld 69. Blades 61 of turbine 59 are fixed to and may rotate turbine shaft 62 which has a threaded portion 63 protruding through casing 67. In Figure 2 it may be noted that threaded portion 63 is screwed through threaded hole 57 in bracket 51.

A tangental airscoop 65 is formed to casing 67 so as to permit air to enter the turbine from the direction in which the missile is to be launched. The scoop is continued on past casing 67 to form an exhausttube 72. A

door71 is mounted at the end of exhaust tube 72 by a spring loaded hinge 73 which tends to close door 71. Door 71 prevents air entering the turbine but permits air to pass out.

Attached to the side of guide 9 by bracket 81 is solenoid 75 having a plunger 77 which is urged down by a spring '79. Plunger 77 may protrude through hole 74 in casing 67- of turbine 59, thus blocking rotation of the turbine blades and also prevents sliding of the stabilizer 5 in guide 9. Suitable conductors 83 and 84 lead from the solenoid winding to a control station 100. Similarly, from missile 1, a pigtail 85 is connected 86 which leads to control station 100.

Secured to carrier structure 3 is a frame 15 which supports cable reel 13. A braking device 17, which in this case might be of the magnetic type, is mounted on frame 15, so as to be capable of stopping or regulating the rotation of reel 13. From brake 17 a suitable conductor leads to control station 100.

Also secured to frame is a cartridge-powered shear 19 having a fixed blade 22 and a moving blade 24. A power cartridge 26 may be ignited in the well known manner via electrical conductor 20 whichleads from control station 100. Fixed blade-22 and movable blade 24 are positioned so that cable 11 passes between them as it is unwound from reel 13.

From reel 13 cable 11 is led through a tube bend 21 which is adapted to mate with the rear of stabilizer 5 as at 16. This permits the cable 11 to be slipped smoothly through the stabilizer 5. Tube bend 21 is supported by strut 23 attached to guide 9. 7

At one end cable 11 is looped through ring 6 of kite 7 andsecured to itself by a cable clamp 8. Kite'7 may be made in various forms to suit conditions, it being shown here as of tapered, cruciform section with a towing ring located on its center-line.

In operation: The launcher being in the condition shown in Figure 1, and a missile being in position, a possible launching sequence would be that shown schematically in Figures 6 to 10, with Figure 6 representing the same ready condition as Figure 1. The carrier structure 3 is assumed to be moving from right to left across the page and desires to launch its missile to its rear.

From circuit B, control station 100, brake 17 is relieved, permitting reel 13 to pay out cable 11 which is under tension caused by the aerodynamic drag on kite 7. This is the condition shown in Figure 7. When a sufficient length of cable is being towed, the missile ignition circuit, which is labeled F at control station 100, is energized so as to start the missile motor. The sole- ,noid circuit, labeled S, may be energized slightly before circuit F, so as to withdraw plunger 77, from hole 74 in turbine casing 67. This permits stabilizer 5 to slide relative to guide 9, and removes plunger 77 from the orbit of the turbine vanes.

In Figure 8 the carrier structure 3 has continued its travel and more of cable 11 has been paid out. The

' thrust of the missile motor and the drag of the missile in the slipstream have separated stabilizer 5 from guide ,9. Missile 1 is here assumed to be at zero-airspeed, but still secured to stabilizer 5 via bands 27 and 49. Stabilizer Sis encompassing cable 11 which is under tension between the carrier and the kite.

to a conductor In Figure 9 the missile has reached stable airspeed in the direction opposite to carrier travel. Air entering airscoop 65 has rotated turbine shaft 62, unscrewing threaded portion 63 from bracket 51 on the missile band. The containing acceleration of the missile disengages button lug 31 from claw 45 and the missile enters free flight ready for guidance.

In Figure 10 the guidance is assumed to be controlling the missile, while the carrier jettisons cable 11 along with kite 7 and stabilizer 5. This might be accomplished by shear 19 under control of circuit J at control station 100, or the cable may be arranged to unwind completely from reel 11 under control of brake 17. It is apparent that many arrangements of stowing, extending and shearing the cable, are possible.

It is desired to point out that kite 7 may be constructed in various forms, so long as it is aerodynamically stable, and has suitable lift and drag characteristics.

For stowage purposes it might also be made with folding fins.

Figure 11 is a graph plotting the successive displacement of carrier 3 and missile 1--for each step of'the launching sequence shown in Figures 6 to 10. The honzontal scale of the graph represents travel and the vertical scale, velocity. Thus the plotting of the carrier travel lies in a straight line as We assume a constant airspeed for it, during launching. In actual practice it would probably vary due to the drag of the cable and kite. The vertical scale is given in units of airspeed, and we will assume that the missile flies stable when it attains a rate of one unit. In Figure 11 the plottings of the missile travel have been connected to form an acceleration curve.

It is then immediately apparent hat the missile requires stabilization for all travel plotting below unit one on the vertical scale. It also is seen that the missile decelerates to zero-airspeed with its fins moving foremost. This is seen schematically when we compare the missiles position in Figure 7 and Figure 8. Tumbling is prevented by the stabilizer which rides on the taut cable.

With some very small missiles it might be possible to eliminate the kite since the drag of the cable alone might provide sufi'icient tension at elevated speeds. This would permit extreme simplicity since the turbine could also be eliminated and the suspension bands could incorporate rings to be used as a two point stabilizer which would fly off this end of the cable with the missile.

The embodiment of this inventiondisclosed herein is tion are possible. In large planes the launcher might be made internal and more than one missile launched along a cable, by the use of delayed ignition. The kite may be made so as to serve as a decoy for hostile missiles.

What I claim is:

In an airborne missile launcher in combination: a rocket missile; 'a guide affixed to an aerial vehicle; an extensible, stabilizing cable, towed by said vehicle substantially in line with said guide; drag means for tensioning said cable; a stabilizer slideable relative to said guide and slideably encompassing said cablej means for preventing sliding of said stabilizer relative to said guide until said sliding is desired; a claw on said stabilizer capable of engaging a button lug affixed to said missile; means for igniting the rocket motor of said missile; a turbine rotor rotatably mounted on said stabilizer and responsive to air flow counter to the direction of said missile, said rotor having a threaded shaft capable of engaging a thread member afiixed to said missile to thereby release said missile.

References Cited in the file of this patent UNITED STATES PATENTS 2,469,449 Baskin May 10, 1949 2,522,422 Wolf Sept. 12,1950 2,771,811 Lauritsen Jan. 28,1958 2,821,396 Seeley Jan. 28, 1958

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