Arrangement for launching interference material

• US 4,333,402 A
• Filed: 10/23/1979
• Issued: 06/08/1982
• Est. Priority Date: 02/23/1978
• Status: Expired due to Term

• Current Assignee: Kaj Lundahl, Sven Landstrom
• Original Assignee: Kaj Lundahl, Sven Landstrom
• Inventors: Landstrom, Sven, Lundahl, Kaj
• Primary Examiner(s): Tudor, Harold
• Application Number:
  US06/189,832
• Time in Patent Office: 959 Days
• Field of Search: 102/501, 102/505, 102/357, 102/340, 102/351, 102/221, 102/222, 102/278, 343/18 E, 343/18 B
• US Class Current: 102/505
• CPC Class Codes: F42B 12/70 for dispensing radar chaff or infrared material radar-reflector targets, active targets transmitting infrared radiation F41J2/00; radar-reflecting surfaces H01Q15/14

Abstract

A projectile (1) containing particles of interference material is fired pneumatically from a launching tube (2). Compressed air, which is supplied to the launching tube and acts on the rear face of the projectile during firing, is conducted both to a loading chamber (19) wherein the air pressure is maintained even after the projectile has left the firing tube, and also via the loading chamber to an expansion chamber (20) in which, after a specific time-lag corresponding with a certain launch height on the trajectory of the projectile, an over-pressure builds up which causes the expansion of the chamber to be initiated with simultaneous expulsion of the interference material from the projectile. The compressed air may also be conducted to the chamber (10) in the projectile wherein the interference material is accommodated, tightly packed, in order to enhance the dispersion thereof.

Claims

1. A projectile that carries a store of radiation interference medium for dispersive discharge at a predetermined time following expulsion of the projectile from a substantially tubular launcher under the force of pressure gas acting upon a rear end of the projectile, said projectile being characterized by:

A. an elongated casing having front and rear end walls,

(1) said rear end wall having a port therein through which pressure gas can enter the interior of the casing during expulsion of the projectile from a launcher, and

(2) one of said end walls being separable from the remainder of the casing in an endwise outward direction;

B. a piston slidable in said direction in the interior of the casing and cooperating with said one end wall to define a compartment in the casing wherein said medium is stored;

C. rigid means providing a connection between said piston and said one end wall whereby the latter is constrained to move in said direction in unison with the piston;

D. a partition fixed in the interior of said casing, between said piston and the other of said end walls, said partition

(1) cooperating with said other end wall to define a first chamber of substantially fixed volume and

(2) cooperating with said piston to define an expandable second chamber, and

(3) having a restricted passage therethrough that provides for retarded flow of pressure gas from said first chamber to said second chamber;

E. means comprising a check valve providing for substantially unrestricted flow of pressure gas from said port to said first chamber but preventing flow of pressure gas from said first chamber through said port; and

F. means providing a disruptable connection between a part fixed in the casing and another part that is fixed to the piston, said disruptable connection confining the piston against motion relative to the casing in said direction until the piston is released by force upon it in excess of a predetermined value, exerted by pressure gas in said second chamber.

2. The projectile of claim 1 in combination with a tubular launcher having an open front end through which the projectile can be expelled and a substantially closed rear end in which there is an inlet for pressure gas by which the projectile is propelled out of the launcher.

3. The projectile of claim 1 further characterized by:

(1) said partition further having a substantially large hole therethrough, to provide for substantially unrestricted communication between said first and second chambers, and

(2) said piston having a projection thereon that is received in said large hole until the piston is released, to thus provide for an abrupt increase of the force upon the piston after its initial movement in said direction.

4. The projectile of claim 3, further characterized by:

said means providing a disruptable connection comprising

(3) a frangible pin extening transversely to said direction and connected between said projection and said partition.

5. The projectile of claim 3, further characterized by:

(3) said rigid means providing a connection between the piston and said one end wall comprising a tube extending coaxially through said compartment and having outlets therein that open radially to said compartment; and

(4) there being a more restricted other passage through said projection and said piston through which pressure gas can controlledly flow from said first chamber into said tube.