Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F41—WEAPONS
  • F41A—FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE
  • F41A1/00—Missile propulsion characterised by the use of explosive or combustible propellant charges
  • F41A1/08—Recoilless guns, i.e. guns having propulsion means producing no recoil
  • F41A1/10—Recoilless guns, i.e. guns having propulsion means producing no recoil a counter projectile being used to balance recoil

Definitions

• the present invention relates to a method and a device for damping the acoustic pressure during firing of missiles of the type which are started by a starter motor in the form of a gas generator fitted in the missile tube-
• a starter motor in the form of a gas generator fitted in the missile tube-
• the gas which is generated by the starter motor acts in a forward direc ⁇ tion on the missile, on the one hand, giving the latter its starting speed, and in a rearward direction, on the other hand, so as to counteract the recoil.
• the missile's own drive motor is then started when the missile is located at a distance from the launching device which is sufficient from the point of view of safety. Starting the missile's own rocket motor when it is still inside the launch tube is not possible in practice in those weapons where the gunner is situated directly alongside the launch tube.
• recoilless weapons which can be of the backblast type or the countermass type.
• the propellant gases which are formed upon combustion of the propellant powder charge are utilized in two directions, i.e. on the one hand forwards in order to give the projectile the desired flight velocity and, on the other hand, rearwards in order to eliminate the recoil .
• the backblast weapons do not permit launching of projectiles of larger calibre since, for the gunner, this would entail far too high and troublesome a pressure behind the weapon.
• Swedish Patent 428604 (81062127) describes a method for reducing the pressure, in such backblast weapons, in the area immediately behind the rear opening of the weapon with the aid of a liquid container which is arranged near this opening and which is burst to pieces during firing, whereupon the liquid is violently mixed with the propellant gases.
• the proposal made in the said patent specification therefore concerns a method for reducing the pressure around the opening of the weapon.
• this proposed improvement there still remains the problem that the purely backblast weapons cannot be given larger calibres and large ranges of fire.
• a method for increasing, in recoilless weapons, the amount of rearward movement upon firing of the weapon, and thereby for permitting an increase in the weight and/or velocity of the projectile without causing an excessively high pressure behind the weapon is to arrange a so-called countermass behind the projectile.
• the countermass should in this case be arranged to fly rearwards out of the barrel when the projectile is launched. So that it does not itself constitute a menace to the gunner, the countermass must be chosen so that it is vaporized or pulverized into a harmless dust behind the weapon.
• Swedish Patent 8205956-9 describes how such an excessively quick quenching of the propellant gases can be prevented by dividing the countermass into two different components, one of which consists as before of a liquid, and the other consists of a particulate material with a preferably greater density than the liquid mass.
• a liquid mass as damping medium in back ⁇ blast weapons is thus already known, and it is also already known per se that a liquid mass, for example in the form of a salt solution, can contribute to quenching the propellant gases in the same type of weapon, namely backblast weapons with damping mass.
• the missile 2 Arranged in the missile tube 1 there is a missile 2 which is ready for launching.
• the missile 2 has its own rocket drive motor (not shown in the figure) which is intended to be started as soon as the missile has reached a predetermined point ahead of the muzzle of the launch tube.
• a starter motor 3 Secured at the rear end of the launch tube, as viewed in the intended direction of launching of the missile, there is a starter motor 3 in the form of a gas generator.
• Around the starter motor 3 there is an annular gas outlet for the propellant gases which act in a rearward direction.
• the liquid charge which characterizes the invention and which is in the form of an annular liquid-filled container, or several annular liquid-filled containers, made of plastic or another material which shatters when the starter motor is ignited, whereupon the liquid is distributed in the space behind the starter tube.
• the reference number 5 indicates an annular fastening member for securing the liquid container 4.
• the latter is in fact conceived as constituting an extra accessory which can be fitted on the missile tube when required, for example when firing has to be carried out from a confined space.
• the front muzzle of the missile tube 1 is covered by a protective cap 6 which is jettisoned when the missile begins to move through the launch tube.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• General Engineering & Computer Science (AREA)
• Lubricants (AREA)
• Toys (AREA)
• Radar Systems Or Details Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (2)

Citations (4)

• 1995
  • 1995-05-11 SE SE9501731A patent/SE504130C2/sv not_active IP Right Cessation
• 1996
  • 1996-05-03 WO PCT/SE1996/000573 patent/WO1996035916A1/en active Application Filing

Patent Citations (4)

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