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
  • F41A1/06—Adjusting the range without varying elevation angle or propellant charge data, e.g. by venting a part of the propulsive charge gases, or by adjusting the capacity of the cartridge or combustion chamber

Definitions

• the present invention relates to the field of firearms, more particularly it is an improvement of the constructive technique of any type of firearms, like for example semiautomatic and not semiautomatic hunting rifles, military assault guns, machine guns, gunnery in general, as well as shotguns, to allow the employment of different types of ammunitions in absolutely safe conditions .
• a device which allows the user to increase or decrease as it suits him and according to the needs of the specific moment, the initial values of the pressure generated by the travelling charge (powder) , following its ignition. Since the pressure that builds up during gunpowder combustion is directly accountable for the speed which is given to the projectile, it is possible to adjust its speed and ensuing kinetic energy, in so doing varying the amount of energy given up to the target which is located at a certain distance.
• the firearms known in the art were conceived and designed to endure and operate with explosive charges of a certain intensity, therefore the pressure that is generated employing ammunitions with the same calibre but with bigger charges is very dangerous as much higher pressure values are reached when compared with those that are expected at the designing stage.
• the "liveliness" of the powder and the limited volume available to combustion gases when they expand, a volume which is made available by the initial headway motion of the projectile, are concurring factors when pressure builds up to unacceptable values.
• both the case and the weapon are mechanically strained, whereas the bullet receives a "ram blow” , which negatively affects its precision on the target.
• the mobile recoiling parts respond in such a way as to be factors that greatly increase the possibilities that structural failures occur in whatever weapon, with consequences that can be easily guessed, especially in machine-gun-type weapons, like said machine guns and military assault shotguns with a shooting range beyond 550-650 shots per minute.
• gunpowder has two important inherent features, the first being that the oxygen which is necessary for combustion to take place is intimately contained within the chemical formula of the gunpowder itself, therefore this can burn in the
• the maximum pressure value is a very useful datum for an appraisal of how close a certain type of ammunition is to its failure limits or to those of a specific weapon.
• Gas recovery systems are known in the art , but their only aim is that of expelling the exploded case so as to maintain the automatism in the functioning cycle of the weapon itself.
• Aim of present invention is that of increasing the volume made available to combustion gases following their expansion, by providing an expansion chamber whose volume can be adjusted.
• a firearm which is equipped with a device, apt to adjust shot initial pressures, by dint of an a.d hoc device which is calibrated to the millimeter range.
• a device which is equipped with a device, apt to adjust shot initial pressures, by dint of an a.d hoc device which is calibrated to the millimeter range.
• Such an adjustment device has a simple and rational shape, and it can be envisaged as substantially comprising three mechanical elements: an expansion chamber that communicates with the firearm muzzle through one connection hole at least, moreover a front and a back adjustment screws.
• Figure 1 schematically shows the very popular Soviet Automat-Kalashnikov assault gun
• FIG. 1 shows automatic gun shown in Figure 1, which has been fitted (only by way of example) with the device object of the present invention
• Figure 3 shows the same gun of Figure 2, provided with a front guard
• a hollow expansion chamber 10 is found to be located, said chamber being equipped with an inside threading 11.
• said threading hosts a clamping screw 12, whilst in its front portion 10, the chamber hosts a second adjustment screw 13, which can be manually operated by dint of a threaded knob 13a located at its end.
• the pitch of threading 11 is preferably in the millimeter range (that is one millimeter of axial movement for each full screw turn) .
• the optimal boring angle with respect to the muzzle axis is 90° .
• Such gases are then conveyed towards the inside of the expansion chamber, compressing the air present inside it. Such an action yields pressures to be reduced to safety levels.
• Pressure is reduced proportionally to the chamber's inner volume, therefore it results to be possible to optimally manage the energy produced by whatever charge load, even that of ammunitions whose charge was not conceived for a specific type of weapon, by simply adjusting screws 12 and 13, that are capable of varying the length and inner volume of the expansion chamber.
• the setting results to be optimal for a correct management of the energy produced by an ammunition characterised by normal charge loading.
• the setting shown in fig. 4E shows the adjustment screw set at the "20" mark in the graduated scale.
• Fig. 4F highlights how back clamping screw 12 is also capable of accomplishing the obstruction of the nearest of holes 14, halving the flow rate of the gas that is bound to be conveyed into expansion chamber 10 underneath.
• screws 12 and 13 are advantageously equipped with their respective sealing rings 27 and 27A, which are made of heat enduring elastic material and accomplish their double aim of avoiding any possible pressure losses along the threading and of eliminating the even remote possibility of undesired uscrewings .

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• General Engineering & Computer Science (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Portable Nailing Machines And Staplers (AREA)
• Slot Machines And Peripheral Devices (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Safety Valves (AREA)
• Golf Clubs (AREA)
• Toys (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

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ID=11405092

Family Applications (1)

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Cited By (1)

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Citations (12)

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• 1997
  • 1997-05-23 IT IT97RM000309A patent/IT1293029B1/it active IP Right Grant
• 1998
  • 1998-05-22 AU AU75479/98A patent/AU7547998A/en not_active Abandoned
  • 1998-05-22 CA CA002291073A patent/CA2291073A1/en not_active Abandoned
  • 1998-05-22 DE DE69812088T patent/DE69812088D1/de not_active Expired - Lifetime
  • 1998-05-22 EP EP98923054A patent/EP0983476B1/en not_active Expired - Lifetime
  • 1998-05-22 WO PCT/IT1998/000128 patent/WO1998053266A1/en active IP Right Grant
  • 1998-05-22 AT AT98923054T patent/ATE234454T1/de not_active IP Right Cessation
• 1999
  • 1999-11-22 US US09/444,508 patent/US6374720B1/en not_active Expired - Fee Related

Patent Citations (12)

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