Ordnance – Recoilless gun – Having breech closure
Patent
1992-07-29
1994-08-16
Brown, David H.
Ordnance
Recoilless gun
Having breech closure
89 1701, F41A 110
Patent
active
053376480
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a countermass for so-called recoilless weapons of the kind which include a barrel which is open at both ends and which, when fired, produce a rearwardly directed impulse or thrust which counteracts the recoil forces engendered by the fired projectile. The countermass is positioned behind the propulsive charge and exits together with the rearwardly exiting propellant gases as the projectile is propelled forwards.
In order to obtain a recoilless weapon, an additional propellant charge has been place behind the projectile and the gas generated thereby is caused to be blown-out rearwardly through an outflow nozzle. This results in a rearwardly directed momentum which can be adapted so as to be equal to the forwardly directed momentum of the projectile. Such a so-called "backblast weapon" produces behind the weapon a pressure of such high magnitude that its effect on the operating personnel places limits on the capacity of the weapon concerned, i.e. on the weight and the muzzle velocity of the projectile used.
It is known to position a countermass behind the propulsive charge, in order to increase the rearwardly directed momentum and therewith increase the capacity of the weapon, without generating excessively high pressure behind the weapon. The countermass is intended to move rapidly rearwards in the barrel, and is normally constructed so that it is vapourized or pulverized behind the weapon. The countermass is normally accelerated as a rigid body in the barrel and then pulverized subsequent to its exit from the barrel. One drawback with known countermass weapons, however, is that they are either too heavy or generate an excessive high risk zone behind the weapon. Compared with existing rocket-type "backblast weapons", the gains have been small both with regard to the effectiveness of the weapon and with regard to the negative effect that the pressure has on the operating personnel.
It is possible to extend the acceleration path of the projectile, so as to increase the muzzle velocity of a given projectile without increasing the size of the propellant charge at the same time. However, this requires a similar extension of the countermass acceleration, or requires the weight of said countermass to be considerably increased. Each increase in the length of the weapon or its weight has a limiting effect on the ease with which the weapon can be handled, and earlier attempts to improve the capacity of recoilless weapons have often resulted in excessively bulky weapons. Weapons whose capacity has been improved by increasing the maximum pressure in the barrel have also resulted in a heavier weapon, since this improvement requires heavy dimensioning of the barrel.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a countermass which will enable the capacity of the weapon to be improved while avoiding the aforesaid drawbacks.
According to the invention, the countermass includes a plurality of mutually sequential and mutually separate countermass bodies, each of which is provided with at least one throughflow passage through which propellant gases can pass. The passage is adapted to the countermass body concerned and is positioned in the countermass so that, when firing the weapon, the countermass bodies will be accelerated consecutively by the exiting propellant gases beginning from the rear. Thus, the time taken for the countermass and the gases to exit through the rear end of the barrel is longer than when a conventional countermass is used.
During firing of the weapon, the highest pressure drop and the greatest acceleration occur on that countermass body which is located furthest to the rear in the barrel at any moment in time. The pressure drop is determined by the configuration and throughflow area of the passage.
The inventive countermass results in reduced maximum pressure in the combustion chamber and, at the same time, a longer duration of relatively high pressure in the barrel. This enables the capacity of the weapon to be increa
REFERENCES:
patent: 4050351 (1977-09-01), Stauff
patent: 4172420 (1979-10-01), Voss et al.
patent: 4244293 (1981-01-01), Grosswendt et al.
patent: 4574680 (1986-03-01), Nicodemus
patent: 4643071 (1987-02-01), Baechler et al.
Brown David H.
Forsvarets Forskningsanstalt
LandOfFree
Countermass for recoilless weapons does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Countermass for recoilless weapons, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Countermass for recoilless weapons will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-944550