US3053479A - Recovery system for test ballistic missiles - Google Patents

Description

2 Sheets-Sheet 1 M. SIEGEL ETAL RECOVERY SYSTEM FOR TEST BALLISTIC MISSILES INVENTORS /%J. 6 5654 L/dJ't/d l d e, JR. BY M L. M

firro/rnw Sept. 11, 1962 Filed July 28, 1959 P 1962 M. SIEGEL ETAL 3,053,479

. RECOVERY SYSTEM FOR TEST BALLISTIC MISSILES Filed July 28, 1959 2 Sheets-Sheet 2 INVENTORS flfosgj $6654 BY dosfpxy gaze, JQ.

, asahs Patented Sept. 11, 1$62 3,053,479 RECOVERY SYSTEM FOR TEST BALLHSTHC MISSHLES Moses Siege! and Joseph Auer, In, Philadelphia, Pa, as-

signors to the United States of America as represented by the Secretary of the Navy Filed July 28, 1959, Ser. No. 830,164 3 Claims. (Cl. 244-14) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention pertains to test launching and recovery of aerial missiles.

Missiles of the type to which the invention relates are thin shelled cylinders weighing approximately thirty thousand pounds and about thirty feet in length. They are provided with an engine or other means for propelling them, a Warhead or satellite, and instruments of various types, as for navigation, collecting geophysical and aerodynamical data, etc.

Because of the flame emitted from the missile, in many instances the site does not permit launching the missile under its own power; it is necessary to delay starting the engine until the missile is clear of the site. Under such conditions, an external catapulting force must be applied to the missile to get it a safe distance away from the launching site. For this purpose, a launching tube is utilized from which the missile is ejected. The expansive force of a compressed fluid, such as air or some other force, released within the tube under the missile catapults it the required height from which its engines may be safely started.

The difficulty encountered in many instances has been the destruction of the missile shortly after launching. Frequently this has been due to the inability of the missile to endure the catapulting force. For the determination of the causes of failure a test vehicle properly instrumented is catapulted and recovered. The vehicles motors are not started and recovery is by some means that will avoid damage to the vehicle and instruments. Among the systems used are a parachute attached to the missile for lowering it safely, and a net for catching the missile at the climax of its flight.

In a parachute recovery system, the size and Weight of the parachute necessary to support a thirty thousand pound missile create a problem of stowing it on the missile. Its location affects missile performanceby adding to drag increasing missile weight and changing the missiles stability. The sites from which launching can take place also are restricted. The missile is catapulted only about 150 feet, which is insufficient for deploying a parachute. Additional height must be obtained by mounting the launcher on a platform, at the brink of a cliff, or in some other manner to give the chute the time required to deploy. Furthermore, intricate timing devices are required for opening the chute and cushioning bags must be provided to absorb the impact of the missile with the landing surface.

The use of nets to catch a catapulted missile has the advantage of not interfering with missile flight; however, the impact with the net damages the missile, which can be expensive considering the missiles cost, or enmeshes it making it diflicult to extract the missile from the net. Because the missile trajectory is nearly vertical, complicated net moving mechanisms are necessary for transporting the net away from the launcher beforemissile ejection and over the launcher for catching the missile. A consequence is that only slow sequences of launchings are possible with net recovery systems.

It is, therefore, an object of this invention to provide an' aerial test vehicle launching and recovery system which will minimize the difiiculties averted to in the systems discussed by providing a device which will take hold of the test vehicle at the apex of its flight, applying an increasing restraining force with the descent of the vehicle and completely arrest it in mid air.

Another object of this invention is a novel test launching and recovery system for an aerial vehicle which substantially avoids interference with the flight of the vehicle and prevents impact of the vehicle with any landing surface.

A further object of the invention is a system in which the various operations in the process of launching and recovering an aerial test vehicle are made to occur automatically in proper sequence in response to a single initiatory act.

Another object of this invention is a method of recovering an ejected missile by attaching a flexible member to the vehicle, overhauling the slack in the member with the rise of the vehicle and applying a yielding restraint with the descent of the vehicle so as to arrest it in mid air.

Other objects will become apparent in the specific construction illustrated and described, it being understood that the invention is not limited thereby, since it is capable of other embodiments. The phraseology is for descriptive purposes and not intended to limit the invention beyond the terms of the appended claims in view of the prior art.

In the drawing,

FIG. 1 is an elevational view of the invention illustratings, by solid lines, the missile and recovery cable in readiness for a launching and showing, in broken lines, some positions in fli ht and recovery of the missile.

FIG. 2 is a fragment of the apparatus of the invention taken on the lines 22 of FIG. 1.

FIG. 3 is a schematic showing of the launching and recovery mechanism.

Referring to FIGS. 1 and 2 of the drawing, the reference numeral it indicates a rocket type aerial missile which is ordinarily ejected from a barrel 12 in substantially a vertical direction under the force of a compressed fluid released within the barrel beneath the rocket. The barrel 12 is disposed in a pit 14 although it can be placed on or above the ground surface as desired. The pit 14 is located substantially between two upright towers, 16 and 16, which may be of steel, wood or other suitable material and are braced (not shown) by guy lines as required. Obviously one tower with a boom may be made to suffice. The towers, 16 and 16, rise above the expected ejection height of the missile 10 and are spanned by a horizontal support member which can be a wire cable 18, as shown, having an end secured to the top of each tower.

Secured to the cable 18 between the towers, 16-16, is a swivelable pulley 20 over which travels a flexible member 22 such as a wire cable, chain, rope or the like. A depending end 24 of the member 22 is fastened to a bail 26 secured to a nose part of the missile by means of bolts or rivets 28. \A nylon strap is a preferred construction for the bail 26 although a steel nose ring with swivel can be used.

The other end of the flexible member 22 is led through pulleys 27 and 2.9 that are secured at the top and bottom of one of the towers 16, respectively, and around a plurality of fixed and movable sheaves, 32 and 34, of an arresting engine 36). After being reeved through the sheaves 32 and 34 the cable 22 is secured to an anchor (not shown) on the engine.

The arresting engine 3t) functions as a means for taking up slack cable and an energy absorber; it has a crosshead 36 on which the movable sheaves 34 are mounted. A piston 38 is attached to the crosshead 36 and is reciprocably movable in a hydraulic cylinder 40. The fixed sheaves 32 and associated cylinder 40 are fixed relative the towers, 16 and 16, and sheaves 34.

For outward movement of piston 38 hydraulic liquid is supplied to engine cylinder 40 from an accumulator tank 42 by a conduit 44 under air pressure which is conducted to the accumulator from a source (not shown) through a pipe 46. A solenoid operated valve 48, normally held closed by a spring 49, controls liquid flow from tank 42 into cylinder 40, and a one-way valve 50 prevents the return of liquid from the cylinder to the tank. Valve 50 may be a fluid metering type for regulating fluid flow into cylinder 40 and thereby the outward movement rate of piston 38. In this manner take-up of cable slack may be increased or decreased, as desired.

To permit inward movement of piston 33 a liquid escape passage from cylinder 40 to a gravity tank 52 is provided by a conduit 54 A flow metering valve 56 in conduit 54 is normally held closed by a spring 58; it is adjustable by turning a nut 6% so that it can be set to open only when subjected to a predetermined pressure by the liquid from cylinder 40. A pump 62 returns bydraulic liquid from gravity tank 52 to the accumulator 42 through a conduit 64. A one-way.valve 66 in conduit 64 prevents flow back to the pump.

The solenoid valve 48 together with a second solenoid valve 68 is controlled by a double pole switch 70; they are arranged to be opened with energization of their coils which takes place with closing of the switch 68. Current for the operation of the solenoids is obtained from some convenient source to which it is connected by the lines L. As is clear from the drawing, the contacts 71 and 72 which connect the line current to solenoids 48 and 68, respectively, are adjustable thus permitting a time delay, if so desired, between their energization.

Solenoid valve 68 in conduit 73 controls the flow of compressed air from a source 74 into the launcher barrel 12 which is used to eject the missile from the barrel.

In operation, missile 10, with cable 22 attached, is loaded into barrel 12 and switch 70 closed. Current from lines L energizes solenoids 48 and 68 thereby opening them. Compressed air from tank '74 flows through valve 68 into barrel 12 and ejects the missile. Opening of valve 48 permits air pressure from conduit 46 to force the hydraulic liquid from tank 42 into cylinder 40 thereby extending piston 38. This movement of the piston separates the fixed and movable sheaves, thereby absorbing the slack in cable 22 created by the rise of the missile, and continues to do so until the missile has reached the apex of its rise.

The descent of the missile pulls cable 22 from the arresting engine thereby forcing piston 38 into cylinder 40. The force produced by the weight and velocity of the missile in descent, which is transmitted to the fluid within cylinder 40, is sufficient to cause valve 56 to be opened thereby permitting a metered flow of fluid from cylinder 40 into the gravity tank 52. The eflect is a gradual reduction in the descent of the missile. Eventu- 4 ally the force is only that of the missile Weight which is insuflicient to open valve 56. At this time the missile will be halted at some point in mid air which can be varied by setting the adjusting nut of valve 56. Further descent of the missile may be made by manually manipulating valve 56.

Having described the invention what is claimed is:

1. Apparatus for launching and recovering an ejected test vehicle comprising launching means for ejecting said vehicle to a predetermined height, an overhead support above said predetermined height, a cable suspended from said support, a cable take-up and arresting means, said cable being adapted to be secured at one end to said vehicle and at the other end to said take-up and arresting means whereby upon ejection of said vehicle said take-up and arresting means overhauls cable slack with rise of said vehicle and yieldingly restrains descent of said vehicle, and means for actuating said launching and takeup and arresting means with one initiatory act.

2. Apparatus for recovering an ejected test vehicle comprising an overhead support, a cable suspended therefrom having an end adapted for securing to said vehicle, a cylinder, a crosshead, a piston extending therefrom reciprocable in said cylinder, the other end of said cable being reeved around said cylinder and crosshead, a source of fluid under pressure, conduit means connecting said source to said cylinder, one-way valve means in said conduit means for admitting fluid into said cylinder during outward movement of said piston, a fluid escape passage connected to said cylinder for discharge of fluid therefrom during inward movement of said piston, and a constant pressure valve in said fluid escape passage for opening with a predetermined pressure.

3. Apparatus for launching and recovering a test vehicle comprising a launcher for ejecting said vehicle, a source of fluid under pressure, means connecting said source of fluid to said launcher, actuating means in said connecting means for controlling fluid flow from said source to said launcher, an overhead support, a cable suspended therefrom having an end adapted to be secured to said vehicle, a cable take-up and arresting engine having a hydraulic fluid cylinder and a piston provided with sheaves, the other end of said cable being reeved through said engine so that outward movement of said piston from said cylinder takes up cable slack, a source of hydraulic fluid under pressure connected to said engine fluid control means permitting one-way flow from said source of hydraulic fluid into said engine for outward movement of said piston, fluid escape means from said engine for discharging fluid flow therefrom when a predetermined pull is applied to said cable and said piston is moved inwardly, and means initiating said actuating and fluid control means simultaneously.

References Cited in the file of this patent UNITED STATES PATENTS

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