Low-recoil, variable-range missile projector

June 6, 1961

A. L. WAXMAN

2,986,973

LOW-RECOIL, VARIABLE-RANGE MISSILE PROJECTOR

Filed Sept. 20, 1954

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United States Patent Office

2,986,973

Patented June 6, 1961

2,986,973

LOW-RECOIL, VARIABLE-RANGE MISSILE; PROJECTOR

Arnold L. Waxman, Albany, N.Y., assignor to the United States of America as represented by the Secretary of the Navy

Filed Sept. 20,1954, Ser. No. 457,320

Claims. (Cl. 89—1.7) (Granted under Title 35, U.S. Code (1952), sec, 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.

The present invention relates to a low-recoil, variablerange missile projector and more particularly to a lowrecoil, variable-range missile projector for antisubmarine warfare which is provided with exhaust gas venting structure to selectively vary the range of the missile while maintaining optimum water entry and underwater trajectory.

Present missile projectors for combating submarines are generally fixed launchers with respect to train and elevation and variations in range can be obtained in a mortarlike method only by changing the amount of launching explosive to be fired. This system is inadequate in that the launching explosives have to be prepacked to fulfill different range requirements, and as each range requires a certain amount of explosive, the number of total ranges possible are severely restricted. The limited ranges afforded by this type of projector necessitate the hazardous operation of maneuvering the attack vessel within the range of the projector in order that the missile can be successfully exploded within an effective proximity to the underwater target.

The prior art antisubmarine missile projectors have the additional disadvantage of being restricted to a relatively small weight missile because their stationary structures cannot effectively counteract large recoil forces.

The present invention is believed to overcome the above-mentioned deficiencies now present in missile projectors for antisubmarine warfare by the provision of a projector which has a low recoil and a variable range made possible by novel structure which allows controlled venting of exhaust gases of the propellent explosive.

An object of the present invention is the provision of a projector for antisubmarine ordnance having controllable means for the escape of propellent gas forces from the expansion chamber to the atmosphere to vary the missile range.

Another object is to provide a low-recoil missile projector which enables a missile to have a fixed angle of water entry and underwater trajectory at various ranges.

A further object of the invention is the provision of means for varying the range of a projected missile without a change in the weight or amount of explosive propellant and without changing the elevation of the barrel of the projector with respect to the horizontal.

A further object is the provision of a relatively lightweight projector in comparison with the weight of the projectile launched.

A still further object of the present invention is the provision of a projector for launching mortar-type ammunition having a remotely controlled range varying system.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a longitudinal sectional view partly in elevation of a preferred embodiment of the invention;

FIG. 2 is a similar view of a modified form of the missile projector; and

FIG. 3 is a perspective view, partially broken away, of the valve and associated linkage.

The present invention is a depth charge projector which has a smooth bore barrel attached to a pressure vessel, such as an expansion chamber, haying circumferentially spaced openings or vents through the wall thereof to vent to the atmosphere propellent gas from the pressure vessel, 10 The projectile range may be controlled by varying these vent openings. Escape ports through the after section of the breech serve to counteract much of the recoil of the projector by permitting the escape of propellent gas forces rearwardly to the atmosphere.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, FIG. 1 illustrates a preferred embodiment wherein a missile projector 1# has a barrel 11 with muzzle end 12 and a chamber end 13. The barrel 20 11 is attached at its chamber end 13 to an expansion chamber 14 having circumferentially spaced vents 15 through the wall 16 thereof leading to the atmosphere. Concentrically spaced from the inner surface 17 of expansion chamber 14 and engaged to the inner surface of 25 a breech plug 18 is a powder case receiver 19 having perforations in the cylindrical wall 20 thereof and being open at the forward end 21 of the receiver just aft of the barrel 11. The cylindrical wall 20 of the powder case receiver 19 extends longitudinally forward of the vents 15 to act as 30 a baffle to direct propellent gas forces toward the barrel and behind a projectile 22 in barrel 11. As the initial thrust force of the explosion of a powder charge pushes the projectile 22 through the barrel 11, the propellent gas is directed rearwardly around the exterior of wall 20 of 35 powder case receiver 19 in the space between the outer surface of the powder case receiver 19 and the inner surface 17 of the expansion chamber wall 16 and through the breech plug 18 via expansion chamber venturi ports 23 axially bored therethrough.

A variation in range of the projectile 22 is obtained by controlling the opening size of vents 15 by a valve such as a sleeve 24 mounted on the outside of wall 16. The sleeve 24 moves longitudinally on said wall 16 over the vents 15 to open or close them fully or partially by 45 means of an actuating mechanism such as worm gear 25 engaging exterior threads 26 on sleeve 24 to rotate the sleeve on interior threads 27 which are meshed with a threaded portion 28 of the expansion chamber wall 16. The worm gear 25 is suitably connected by linkage 29 to 50 a range control master 3® at a removed position from the projector 10. The sleeve 24 is provided with a forwardly open integral bell flange 31 to direct the expelled gases forwardly thus to some extent compensate for the tendency toward overcompensation for the recoil energy 55 at shorter target ranges.

The impulse ammunition used as an explosive propellent force may be of the type commonly used in launching depth charges from mortar or bomb type projectors. The propelling charge is normally contained in a cartridge case ⁶⁰ having a forward disk and end wad and, on firing the propelling charge, the disk retains the gas of the initial explosion to promote a build-up of pressure in order that a proper pressure for efficient combustion is established and that, when released, the pressure will over55 come the inertia of the projectile to start its expulsion.

The projectile best adapted for ammunition for the present invention is the bomb type, vane stabilized depth charge having the front end, or ogive, of a blunt curvajq ture. The blunt nose of the projectile is chosen because it best retains the water entry and underwater trajectory characteristics desired.

2.986.97

A faired nose projectile has the inherent fault of resurfacing due to the forces of the water against the nose curved surface. The projectile 22 may have a gas seal ring such as ring 32 in close tolerance with the barrel bore to prevent the propellent gases from going forward around the projectile rather than pushing behind the projectile.

A modification of the projector of FIG. 1 is the projector illustrated in FIG. 2 which has a barrel 41, an expansion chamber 42 connected to the after end of barrel 41, and a breech plug 43 closing the end of the expansion chamber 42 and having a venturi port 44 axially bored therethrough. A laterally extending side member 45 is attached to the expansion chamber 42 to receive a powder charge in the outermost portion thereof. The cylindrical wall 46 of the side member 45 has radially spaced vents 47 located adjacent to and equidistant from the expansion chamber and the side member juncture 50. A hatch 48 is provided in the end of side member 45 to receive the propellent charge 49. A three-way valve 51, as shown by FIG. 3, rotatably secured within the side member 45 in a plane perpendicular to the longitudinal axis of the side member so as to cooperate with the vents 47 to vary the openings thereof to the atmosphere. The centrally located passage 52 of three-way valve 51 connects the side member with expansion chamber 42. Valve 51 is rotated by either a manually or electrically operated lever arm 53 which extends from the exterior of the side member through slot 54 to a rigid connection 55 with rotatable valve 51.

Range selection is procured in the projector modification of FIG. 2 by adjusting the vent opening by valve 51 to allow a quantity of propellent gas to escape therethrough. The main force of the propellent gas continues through the passage 52 to expansion chamber 42 and thence to the barrel 41 to expel the projectile 56. Recoil of the projector 57 is counteracted by the provision of venturi port 44 which allows the rearward escape of propellent gas.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.