US 2986973 A
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Description (OCR text may contain errors)
June 6,1961 A. L. WAXMAN 2,986,973
LOW-RECOIL, VARIABLE-RANGE MISSILE PROJECTOR Filed Sept. 20, 1954 United States Patent Y 2,986,973. Low-RECOIL, VARIALE-RANGE Mesnil?. PRoJEc'roR The invention described herein may be manufactured and used by or for the Government of the United States ef rAmerica for governmental purposes without the payment of any royalties thereon or therefor.
The present invention relates toa 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 ei. the missile While maintaining Optimum.. Water entry and underwater trajectery- Present missile projectors for combating Submarines are generally fixed launchers with respect to train and elevation and variations in range can be obtainedv in a mortarlike method only by changing the amount of 'launching explosive to be red. This system is inadequate in that the launching explosives have to be prepac'ked to fuliill different range requirements, yand as each `range requires a certain amount of explosive, the number of total ranges possible are severely restricted. The limited ranges aforded 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 ybeing restricted to a relatively small weight missile because their stationary structures cannot effectively counteract'large recoil forces.
The present invention is vbelieved 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 xed 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 modied form of the mis.- sile 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, having circumferentially spaced openings or vents through the wall thereof to vent to the atmosphere propellent gas from the pressure vessel. 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 through,- out the several views, FIG. 1 illustrates a preferred ernbodiment wherein a missile projector 10 has a barrel 1 1 with muzzle end 12 and a chamber end 13. The barrel 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 a breech plug 18 is a powder case receiver A19 having lperforations in the cylindrical wall 20 thereof and being open at the forward end Z1 of the receiver just aft of the barrel 1v1. The cylindrical wall 20 of the powder case receiver 19 extends longitudinally forward of the vents 15 to act as a bale to direct propellent gas forces toward the barrel 11 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 2.0 of 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 22j is obtained by controlling the opening size of vents 15 by a valve such asa sleeve 24 mounted on the outside of wall 16. The sleeve 24 moves longitudinally on said wall 16 over the vents 1S to open or close them fully or partially by 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 a range control master 30 at a removed position from the projector 10. The sleeve 214 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 at shorter target ranges.
The impulse ammunition used as an explosive propellent force may be of the type commonly used in launching depth charges fro-m mortar or bomb type projectors. The propelling charge is normally contained in a cartridge case having a forward disk and end wad and, on tiring 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 e'icient combustion is established and that, when released, the pressure will overcome 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 curvature. The blunt nose of the projectile is chosen because tory characteristics desired.
A faired nose projectile has the inherent fault of resurfacing due to the forces of the water against the nose curved surface.Y The projectile 22 may have a gas seal ring such as ring 32 in Vclose tolerance with the barrel bore to prevent the propellentv gases from going'forward around the projectile rather than pushing behind the projectile. Y Y
A modification of the projector of FIG. l 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 modication 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 ot 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.
What is claimed is:
l. A low-recoil, variable-range missile projector cornprising a barrel, an expansion chamber having a Venturi port axially extending through the rear thereof and connected to said barrel, a powder case receiving member laterally attached to said expansion chamber by a valve containing means intermediate said expansion chamber and said powder case receiving member, said valve containing means having radially spaced vents located through the wall thereof, a valve rotatably mounted within said valve containing means having an opening axially therethrough to allow passage of gases from said powder case receiving member to said expansion chamber and further having a plurality of ports positioned to be in alignment with said radially spaced vents when the valve is in a predetermined position, and means to adjust said valve whereby the alignment of the missile projector is unaiected by variable venting of burning gases to the atmosphere. v
2. A low-recoil, variable-range missile projector as in claim 1 wherein said means'to yactuate the valve comprises a lever arm connected to said valve and extending outwardly through Ia slotted opening in the wall of said powder case receiving member.
3. A low-recoil, variable-range ymissile projector comprising, a barrel, an expansion chamber connected to said barrel and having a venturi port axially extending through the rear thereof, a powder charge receiving member later# ally attached to said expansion chamber by a casing means, said casing means having radial vents, an annular valve rotatably mounted Within said casing means and having openings extending radially therethrough, said openings being so arranged as to fall in alignment with said vents when the valveris rotated into a predetermined position, said valve having an actuating member attached thereto and extending through a slotted opening inthe wall of said powder charge receiving member for rotating said valve to produce variable venting of burning gases to the atmosphere.
References Cited in the le of this patent UNITED STATES PATENTS 1,299,136 Davidson Apr. 1, 1919 1,322,980 Wale Nov. 25, 1919 1,559,183 Rimailho Oct. 27, 1925 2,093,058 Savani Sept. 14, 1937 2,094,305 Savani Sept. 28, 1937 2,378,735 Shaffer June 19, 1945 2,417,983 Holman et al Mar. 25, 1947 2,444,949 Musser July 13, 1948 FOREIGN PATENTS 404,186 Great Britain Jan. 11, 1934