Propellent charge powder for barrel-type weapons

Details Propellent charge powder for barrel-type weapons Propellent charge powder for barrel-type weapons

1999-07-30

2001-10-30

Jordan, Charles T. (Department: 3641)

Explosive and thermic compositions or charges

Structure or arrangement of component or product

Solid particles dispersed in solid solution or matrix

C149S019100, C149S019800, C149S092000

Reexamination Certificate

active

06309484

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a propellent charge powder for barrel-type weapons having a plasticizer on the basis of nitramine and nitrocellulose, nitramine and energetic and non-energetic plastic binders, or nitrocellulose, or an explosive.
2. Discussion of the Prior Art
DE 35 00 068 C1 concerns a monobasic or polybasic propellent charge powder using O,O′-dioxy azobenzene for the purposes of improving mechanical properties at down to −55° C. No information is given about temperature coefficients. In addition no diaza compound is used.
DE 33 16 676 C2 describes a propellant composition based on nitrocellulose with hexogen, a blasting oil and plasticiser or softener as well as nitroglycerine. No mention is made of a diaza compound however and there is also no information about temperature coefficients.
DE 30 33 519 C2 concerns a rocket propellant for a usually low pressure range upon combustion. No information is given about the pressure range which is relevant for propellent charge powder of over 3000 bars. Admittedly, some indications are afforded in regard to mechanical properties in a wide temperature range. There is however no information about temperature coefficients, dependency of the gas pressure on the temperatures of the propellent charge powder. The energetic plasticiser or softener is blasting oil such or Ngl but no diaza compound.
A further known propellent charge powder as disclosed in DE 22 60 259 A involves a propellant composition for rockets and not a propellent charge for barrel-type weapons. That propellent charge, like generally all dibasic propellants, is heavily temperature-dependent in the temperature range which is of interest.
U.S. Pat. No. 4,567,296 A describes an energetic plasticiser or softener on the basis of a fluorine-bearing aza compound. That aza compound, more specifically 1-fluoro-1,1,5-trinitro-3-oxa-5-azahexane is not suitable for use in barrel-type weapons and propellent charge powders. Upon combustion in a weapon, the steel is destroyed, particularly at the usually high pressures and temperatures. In addition that compound gives rise to a major disposal problem. The starting material 2-nitro-2-aza-1 propanol is chemically basically different from a diaza compound.
Upon firing munitions with conventional propellent charge powder, the ballistic values maximum pressure and projectile velocity are also heavily temperature-dependent. The pressure and the velocity of 120 mm KE-munition rise from −40° C. to +50° C. by about 1500 bars and 165 m/s, that is to say 10% of the reference or target speed at normal temperature of +21° C. On the basis thereof, on the one hand the armament operational gas pressure cannot be fully utilised at normal temperature, which would result in a high velocity, and on the other hand, because of the only inaccurately known current initial projectile velocity the hit probability is markedly reduced or measures must be taken to ascertain the current projectile velocity in order not to suffer a loss in terms of hit accuracy.
SUMMARY OF THE INVENTION
The object of the present invention is to propose a propellent charge powder for barrel-type weapons, which has a low temperature coefficient in the temperature range of −50° C. to +70° C.
The invention attains the foregoing object in that the plasticizer comprises a mixture of at least two chemically different dinitro diaza compounds.
By virtue of the use of a particular plasticiser or softener the invention makes it possible to produce and use propellent charge powder with a low temperature coefficient. In other words: a propellent charge powder of that kind makes it possible to fire armament munition with almost dibasic propellants, is heavily temperature-dependent in the temperature range which is of interest.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
U.S. Pat. No. 4,567,296 A describes an energetic plasticiser or softener on the basis of a fluorine-bearing aza compound. That aza compound, more specifically 1-fluoro-1,1,5-trinitro-3-oxa-5-azahexane is not suitable for use in barrel-type weapons and propellent charge powders. Upon combustion in a weapon, the steel is destroyed, particularly at the usually high pressures and temperatures. In addition that compound gives rise to a major disposal problem. The starting material 2-nitro-2-aza-1 propanol is chemically basically different from the dinitro diaza compounds according to the invention.
A better plasticisable propellent charge powder, in accordance with U.S. Pat. No. 4,457,791, is based on a plasticiser DMMD. Further plasticisers as additives to that specified are not provided. There is no indication that the temperature coefficient upon combustion is positively influenced.
Transformation or the gas-generation rate of conventional monobasic and polybasic propellent charge powders is highly temperature-dependent. The greater the initial powder temperature, that much faster is combustion of the propellent charge powder. That property is substance-specific and can be described for example to a good degree of approximation by the combustion law as follows:
γ
=
β
·
(
p
p
o
)
α
·
ⅇ
τ
⁢
 
⁢
T
with T as the temperature of the propellent charge powder. In that equation &tgr; denotes the so-called temperature coefficient of the propellent charge powder, which is of different values for the various powder compositions and which represents a substance constant. In addition &ggr; denotes the velocity with which the combustion front progresses, &bgr; and &agr; represent substance constants and p is the pressure under which the propellent charge powder is, wherein p
o
is atmospheric pressure.
As a result of the temperature-dependency of the combustion speed of the propellent charge powder, the maximum gas pressure which occurs when firing munition with conventional monobasic and polybasic propellent charge powder from an armament, in the charge chamber of the weapon, and thus also the projectile launch velocity are also severely temperature-dependent.
The pressure and the velocity of 120 mm KE-munition rise from −40° C. to +50° C. by about 1500 bars and 165 m/s, that is to say 10% of the reference or target speed at normal temperature of +21° C. On the basis thereof, on the one hand the armament operational gas pressure cannot be fully utilised at normal temperature, which would result in a high velocity, and on the other hand, because of the only inaccurately known current powder temperature and thus the initial projectile velocity the hit probability is markedly reduced or measures must be taken to ascertain the current projectile velocity in order not to suffer a loss in terms of hit accuracy.
The object of the present invention is to propose a propellent charge powder for barrel-type weapons, which has a low temperature coefficient in the temperature range of −50° C. to +70° C. so that in that way the specified ballistic values of maximum pressure and projectile velocity depend only slightly on the powder temperature.
The invention attains that object in accordance with the characterising features of claim
1
. Advantageous developments of the invention are set forth in the appendant claims.
By virtue of the use of a particular plasticiser or softener the invention makes it possible to produce and use propellent charge powder with a low temperature coefficient. In other words: a propellent charge powder of that kind makes it possible to fire armament munition with almost constant values in respect of maximum pressure and projectile velocity in the entire temperature range of −50° C. to +70° C.


REFERENCES:
patent: 3697341 (1972-10-01), Rosher et al.
patent: 4002514 (1977-01-01), Plomer et al.
patent: 4085123 (1978-04-01), Flanagan et al.
patent: 4216039 (1980-08-01), Pierce
patent: 4432817 (1984-02-01), Frankel et al.
patent: 4457791 (1984-07-01), Gill et al.
patent: 4476322 (1984-10-01), Chang et al.
patent: 4482404 (1984-11-01), Witucki e

Affiliated with

Also associated with

Rating

Propellent charge powder for barrel-type 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 Propellent charge powder for barrel-type weapons, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Propellent charge powder for barrel-type weapons will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2613188