Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B5/00—Cartridge ammunition, e.g. separately-loaded propellant charges
  • F42B5/02—Cartridges, i.e. cases with charge and missile
  • F42B5/16—Cartridges, i.e. cases with charge and missile characterised by composition or physical dimensions or form of propellant charge, with or without projectile, or powder
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
  • C06B45/02—Compositions or products which are defined by structure or arrangement of component of product comprising particles of diverse size or shape

Definitions

• the technical sector of the present invention is that of propellant charges of ammunition with metallic or non-metallic casings.
• compact propellant charges have been proposed, that is to say blocks of one or more powders in mixture produced in particular under hot pressure in the presence of a thermosetting binder in proportions varying from 5 to 10%, most often.
• the manufacturing process for these blocks is relatively long and requires, in addition to cooking, the use of a mold resistant to pressures of the order of 10 8 Pa.
• the compacted propellant charges thus obtained have dimensional stability. insufficient when subjected to thermal cycles of accelerated aging. Indeed, the compressed powder blocks expand and contract, which results in an evolution of the binder structure considerably disturbing the ballistic behavior. To overcome this drawback, it is essential to subject the compacted loads to one or more thermal stabilization treatments.
• the invention aims to remedy the aforementioned drawbacks by providing a propellant charge comprising at least two powders whose filling coefficient is significantly greater than that of bulk loads and which does not require any compacting operation. It also aims to provide a propellant charge which can be applied to a socket of any kind with or without constriction. It also aims to provide a load which can be introduced into a socket automatically or semi-automatically very quickly. It also has the aim of conferring on the fuel socket loads a suitable mechanical strength.
• the invention therefore relates to a propellant charge of ammunition for weapons of all calibers intended to increase the filling coefficient of a metal or combustible case, characterized in that it is constituted by the association of a powder with perforations and a monotubular powder according to the respective percentages 60 to 85% and 15 to 40% and a coating material according to a small percentage.
• the propellant charge can be constituted by the association of a perforation powder and a powder with spherical grains according to the respective percentages 65 to 80% and 20 to 35% and a coating material according to a small percentage.
• the propellant charge can be constituted by the association of a perforation powder, a monotubular powder and a powder with spherical grains according to the respective rasse percentages 60 to 85%, 15 to 40% and 0 to 20 % and a coating material in a small percentage.
• the percentage of coating material is between 0.5 and 3.5% relative to the total mass of powder.
• the coating material is an oily binder, for example dibutylphthalate or a polyisocyanate, in particular a diisocyanate.
• the coating material is a thermosetting prepolymer, for example a polyurethane.
• the mass of powder is greater than that used with the casings without constriction. he It is therefore necessary to significantly increase the percentage of binder to intensify its role as a surface moderator of combustion, so that the pressure generated in the weapon is compatible with it.
• the grain dimensions of the three powders must be adapted to the caliber of the ammunition and it is preferable that the thickness of each of the powders is substantially equivalent, the thickness of the monotubular powder generally being the smallest, which is advantageous from the point of view of dimensional association, a ballistic correction being brought about by a more advanced surface moderating treatment.
• a very first result obtained by the loading according to the invention is a very significant increase in the filling coefficient of the sleeve which reaches at least 1200 g / dm 3 compared to the loading carried out automatically with powder in bulk.
• the coating material plays the role of additional surface moderator of combustion.
• the constituents of the charge after filling the sleeve are transformed into a solid aggregate having a considerable mechanical resistance which is particularly suitable for the loading of combustible sleeves.
• a fuel assembly with good mechanical strength is thus obtained.
• Polyisocyanates, thanks to chemical reactions of connection with the nitrocellulose of the powders lead to fixed loads having mechanical properties comparable to those obtained from thermosetting binders.
• the frozen loading in situ therefore does not float as is the case for previously compacted loads and withstands thermal aging cycles very well, for example a thermohygrometric cycle.
• an axial channel When carrying out large loads, for example for 120 mm ammunition, an axial channel must be made in a known manner in the load so as to facilitate ignition, to ensure operational safety and to obtain good regularity of fire. On the other hand, it is sometimes necessary to provide an axial channel in the loads for necked bushing, especially when this necked is very accentuated, which most often corresponds to high performance ammunition.
• the powders usually used in the manufacture of 20 to 30 mm caliber ammunition must undergo a very extensive moderating treatment; this treatment can be carried out in part or in whole by increasing the proportion of binder.
• the procedure is as follows or in an equivalent manner.
• the powders are mixed according to the percentages indicated in a few seconds in a mixer with a coating material suitably chosen in small proportion and then the non-solidified mass thus obtained is introduced into the socket.
• the positioning of the projectile makes it possible to complete the task of the load.
• the coating material is a thermosetting prepolymer
• the ammunition thus produced is then subjected to baking at a temperature below 100 ° C.
• the load solidifies in the socket and adheres to the wall thereof. It can therefore be seen that the loading according to the invention does not require the use of high pressure, for example of the order of 8.10 7 Pa that is required to produce a compacted loading and can be implemented on a socket having or not a constriction.
• Examples 1 to 3 illustrate the embodiment according to which the coating material is an oily binder and Examples 4 to 8 the embodiment according to which the coating material is a thermosetting prepolymer.
• the speed of the projectile is conventionally measured at 25 meters; the pressure is conventionally measured using a piezoelectric device; the percentages indicated are percentages by mass.
• the percentage of binder is calculated by relative to the total mass of powder.
• the powders used consist of nitrocellulose (simple base).
• the monotubular cylindrical grains have a thickness of between 0.3 and 0.4 mm; the cylindrical grains with 19 holes have a web of 0.36 mm; the spherical grains have a diameter of 0.35 to 0.45 nm.
• thermosetting prepolymer known under the name of "HSV”, sold by the company “Vos Schemie Soloplast", is used.
• This prepolymer is of the polyurethane type.
• the loading density is: 1200 g / dm 3
• Ammunition is produced under the same conditions as above with the same percentages of powder but with 1.5% of HSV.
• the loading density is: 1200 g / dm 3
• the dispersion of the shooting results increases when the proportion of binder increases.
• Ammunition produced according to Example 5 is subjected to 10 aging cycles of 24 hours each (thermo-hygrometric cycle).

Landscapes

• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Paints Or Removers (AREA)
• Operating, Guiding And Securing Of Roll- Type Closing Members (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Furnace Housings, Linings, Walls, And Ceilings (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Polyurethanes Or Polyureas (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (11)

Cited By (5)

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Citations (10)

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• 1978
  • 1978-04-13 FR FR7810854A patent/FR2422925A1/fr active Granted
• 1979
  • 1979-04-06 AU AU45899/79A patent/AU534179B2/en not_active Expired
  • 1979-04-10 NO NO791216A patent/NO146516C/no unknown
  • 1979-04-11 EG EG219/79A patent/EG14237A/xx active
  • 1979-04-11 ES ES479526A patent/ES479526A0/es active Granted
  • 1979-04-12 EP EP79400244A patent/EP0005112B1/de not_active Expired
  • 1979-04-12 IT IT21822/79A patent/IT1115185B/it active
  • 1979-04-12 BE BE0/194568A patent/BE875534A/xx not_active IP Right Cessation
  • 1979-04-12 DE DE7979400244T patent/DE2961805D1/de not_active Expired
  • 1979-04-12 ZA ZA791753A patent/ZA791753B/xx unknown
  • 1979-04-20 IL IL57101A patent/IL57101A/xx unknown

Patent Citations (10)

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