US3641867A - Reduced recoil caseless cartridge machine gun - Google Patents

Abstract

A forward flow, chamber-gas-pressure-actuated automatic firearm employing caseless ammunition and nonmoving barrel. Chamber bolt blown forward parallel to the bore, permitting antirecoil gas thrust and counterrecoil impact of parts operating forward opening breech mechanism in the form of a gas check ball valve. Provides for accelerated autoloading of projectile and subsequent feeding of solid propellant charge in such a manner that the projectile is seated in the bore and the breech sealed before the front-loading charge is delivered to the ignition portion of the chamber.

Description

O United States Patent 1 1 3,641,867 Junker 1 Feb. 15, 1972 [54] REDUCED RECOIL CASELESS 3,283,657 11/1966 Kravle ..42 1 3 CARTRIDGE MACHINE GUN 3,320,856 5/1967 Robinson ..89/ 17 3,521,523 7/1970 Langenhoven ..42/l R [72] lnventor: Ralph Daniel Junker, 33 North Mam St.,

Southampton, 11968 OTHER PUBLICATIONS [22] Filed: Mar. 11, 1970 Johnson, Jr., Melvm M. and Haven, Charles T., AUTO [211 Appl. No.: 883,416 MATIC WEAPONS OF THE WORLD. 1944, p. 7..

(copy in Art Unit 221) [52] US. Cl. ..89l1.704, 89/17, 89/33 A,

89/l94 Primary Exanuner-Ben3am1n A. Borchelt 511 1111. C1 ..F4ld 11/06, F4ld 1 1/14 minim P Bentley [58] Field of Search ...42/1 R, 2, 6, 14, 15; 89/1 R,

89/1 B, 1.7, 1.701, 1.704, 1.705, 7, a, 17, 33 A, 1 1 ABSTRACT A forward flow, charnber-gas-pressure-actuated automatic firearm employing caseless ammunition and nonmoving bar- Rekm rel. Chamber bolt blown forward parallel to the bore, per- UNTED STATES PATENTS mitting antirecoil gas thrust and counterrecoil impact of parts operating forward opening breech mechanism in the form of a 429,592 6/1890 Babcock ..89/7 gas check ball valve. Provides for accelerated aumload'mg of 619,026 2/1399 Sims 7 projectile and subsequent feeding of solid propellant charge in 908,294 2/1908 M3183 89/191 x such a manner that the projectile is seated in the bore and the 941,662 11/ breech sealed before the front-loading charge is delivered [0 2,365,459 12/ 1944 Dobremysl..... .89/33 A the ignition portion of the chamber. 2,947,221 8/1960 Griffin et al.... .8911 R X 3,160,064 12/1964 Bell et al ..89/7 X 3 Claims, 3 Drawing Figures \v I in REDUCED RECOIL CASELESS CARTRIDGE MACHINE GUN Reduction of recoil and improved solutions of problems intrinsic to the use of caseless cartridge ammunition are interrelated objectives of a new automatic machine gun.

in the automatic machine gun where some of the power of propellant explosion is employed in the action of producing a breech opening for cartridge feeding, there have been various attempts to dissipate some of the recoil-producing energies within the gun by imposing certain operating work loads forward. To date, most of these attempts have been of very limited value simply because this impulse arrives too late after ignition to counteract rearward gun displacement.

A prime objective of the novel gun is to step up the rate of forward energy transfer so that effective internal recoil braking will occur before the main gun mass has had a chance to attain its full rearward velocity and thus to limit rearward (recoil) displacement.

This requires: that while chamber gases expand there must be some "give" in the projectile-gun interaction to prolong and cushion this interaction; that no power of explosion be expended in a rearward direction for the purpose of producing a breech opening; that all action parts move in a forward direction and transfer their kinetic energies forward; and that the transfer of energies forward starts from peak chamber pressures (without imposing added work loads to the rear); and that the responding part be integral to the chamber and that its weight be compatible with high velocities as compared to the main gun mass.

In addition it is required that caseless ammunition be used because of the need to lift restrictions on initial bolt movement and chamber configuration.

The use of caseless ammunition, in turn, requires solutions to problems intrinsic in its use, namely: means for ignition must be provided", flash must be prevented from reaching the magazine; rearward gas leakage must be prevented; and premature injection of the propellant into the ignition chamber should be prevented lest unintended ignition by cook off occur.

The solutions to all of these problems obviously must involve a new gun design with unidirectional forward action thrust in the gas pressure phase of operation.

The prime solutions begin with the following observations:

a. The usual high cyclic rate hand-held machine gun has a breech bolt opening to the rear under at least partial gas pressure. This pressure imparts to the bolt a kinetic energy which may comprise a significant portion of the recoil force to which the total gun is subjected.

b. The second observation is that while it is not usual to curve gun barrels it is completely unusual to bend" the gun through the chamber so that the receiver (the normal recipient of bolt thrust in automatic operation) is reversed.

c. The third observation is that an expanding chamber is an effective way of delaying or reducing the efficiency of rearward energy transfer (recoiless principle) since projectile and gun interact through the medium of expanding chamber gases.

In the novel gun, bolt kinetic energy is transferred forward rapidly and effectively at the same time that there is a reduction in efficiency and rate of rearward energy transfer through a forward expanding combustion chamber. The result of both of these measures is a reduction in the total recoil force which comes to be applied on the mount or shooter, thus improving the effectiveness of automatic fire by making it easier for the gun to be held on the point of aim.

Redirection of bolt thrust may be used in nonautomatic guns only for the purpose of reducing rearward gun displacement. When, however, the energies of a forward thrusting chamber bolt are harnessed to perform all the work of automatic operation this becomes a new way of operating a fixedbarreled automatic machine gun since the gun does not use any of the following known practical ways of employing the power of explosion for automatic operation: rearward recoiling masses; gas pressure tapped from the barrel; rearward gas release; or barrel displacement in any direction.

Within the novel gun the power for automatic operation is all transferred directly forward through a bolt displacing forward, as part of an expanding chamber, no action part moves to the rear in the power stroke and a rearward chamber opening does not occur until all gas pressures are vented forward.

Also novel within the gun are: a forward opening, self-sealing gas check ball valve breech; and autoloading of bipart ammunition in separate stages of the operating cycle both to increase the safety of caseless cartridge ammunition and to simplify ignition.

Projectile and propellant feed separately at different stages of the cycle. The projectile is fed in the power stroke and the breech closed and sealed before the bolt returns with a new propellant charge from the forward magazine to inject the propellant into the ignition chamber causing ignition by percussion and a repetition of the cycle.

The overall capability is then of a short span, practical, caseless cartridge machine gun readily controllable at high cyclic rates because of reduced recoil, firing inexpensive and lightweight caseless ammunition.

The specific embodiment of the many novel features within the gun and the mode of operation of cooperating parts result in so many improvements that the invented material is best described as a new automatic machine gun system. It is, for identification purposes, called 1" chamber bolt recoil reverse system. Its principles are applicable to firearms of many types.

The inventive ideas are capable of embodiment in a variety of mechanical structures, one of which is shown in the accompanying drawing; but it is to be understood that such drawings are for the purpose of illustration only and are not designed to define the limits of the invention, reference being had to the appended claims for this purpose.

The prime features of the novel automatic machine gun are shown in three semischematic representations of the gun in different operational stages. All views are partial cross-sectional side views.

FIG. 1 represents a preignition view when the auto cycle has been interrupted by bolt sear engagement.

FIG. 2 represents ignition.

FIG. 3 shows the mechanism in counter recoil thrust and represents the power stroke.

Chamber! and barrel 2 are the main structural components shown. The receiver is represented as a forward extension of the main part of the combustion chamber. The upper end of the combustion chamber is roofed by the barrel and contains the first projectile 3, gas check ball valve 4 and the ball return spring 5. The barrel is quick removable for cleaning of these components.

in FIG. 1 the preloaded first projectile is in place and the breech partially sealed by the gas check ball as it is supported by the retaining spring at the projectile feed portal 6. All parts are at rest with the bolt sear 7 engaged and holding the bolt 8 forward.

When the bolt sear is released, the bolt return spring 9 drives the bolt back carrying with it the first propellant charge 10.

ln FIG. 2 the bolt ram impact on the first propellant charge has caused ignition. From the ignition part of the chamber, the expanding gases force the gas check ball into full obturation and simultaneously displace the first projectile and the bolt forward.

Because of the differential rates of displacement of the projectile and bolt, the projectile will have been discharged from the muzzle end before the bolt displacing forward in the cylindrical forward extension of the combustion chamber has had a chance to clear the gas vent tube 11 and 12.

This gas vent tube serves as a conduit for gases to bypass the propellant port 13 and the bolt, and discharges the gases ahead of the bolt into the distal receiver where the gas pressure serves to assist in cushioning the impact of bolt arrival and where bolt arrival in turn speeds venting of residual gases.

The propellant magazine 14 is further protected by a magazine cover 15 which does not open until the bolt lug 16 engages a dual purpose acceleration cam 17. This cam pries open the magazine cover at one end and simultaneously at the opposite end rapidly thrusts a projectile loading ram operating rod 18 forward.

FIG. 3 represents the consequences of this action. The rammer proper 19 has thrust another projectile 20 from a lateral feeding projectile magazine (not shown) against the gas check ball displacing the ball into a chamber recess and continuing until projectile insertion to battery condition is complete.

With complete transfer of bolt kinetic energy as forward thrust to gun structure via bolt return spring, accelerator and rammer operating rod return spring 21, forward bolt motion stops and the bolt starts the return trip releasing the accelerator to withdraw the projectile rammer and allowing the gas check ball retaining spring to return the ball to obturation position. Because of its lighter weight and because a short distance of bolt travel allows amplified rammer movement, this process takes place quickly and except for a short distance of bolt travel independently of bolt movement. At this point, the cycle may be stopped by allowing the bolt sear to engage. If so, the conditions of F l0. 1 are again met, i.e., a projectile is in place and the breech sealed as the bolt is posed to thrust a new propellant charge 22 into the ignition part of the chamber.

Not shown for reasons of simplicity are magazine details and details of rammer rod disassembly.

Having described my invention, what I desire to claim as new is:

1. An automatic firearm comprising:

a receiver;

a barrel attached to said receiver, said barrel having a longitudinal bore extending from a forward end to a rearward end;

a combustion chamber in said receiver, said combustion chamber having a longitudinal axis parallel to but laterally spaced from said longitudinal bore of said barrel, said combustion chamber having a propellant impact surface at a rear end thereof, and a propellant introduction port at a forward end thereof;

a gas passage communicating between the rearward end of said longitudinal bore of said barrel and the rear end of said combustion chamber;

forwardly displaceable breech block means at the rear end ofsaid barrel, and return means therefor;

bolt means mounted within said combustion chamber for longitudinal reciprocation between a forward position forward of said propellant introduction port and a rearward position adjacent said propellant impact surface, said bolt means having a lug thereon;

bolt driving spring means for driving said bolt means rearwardly;

sear means for holding said bolt against said driving spring means;

projectile loading rarn means for forwardly ramming a projectile and forwardly displacing said breech block means;

acceleration cam means operatively connected between said lug on said bolt means and said projectile ram means for accelerating the forward movement of the projectile ram means with respect to forward movement of said bolt; and

an acceleration cam means and projectile ram means return spring;

whereby upon release of the bolt by the sear the bolt-driving spring moves the bolt past the propellant introduction port picking up the propellant, the bolt then impacts the propellant against the combustion chamber end wall to initiate combustion, gases of combustion flow through the gas passage into the rear end of the longitudinal bore of the barrel thereby discharging a projectile and the gases of combustion force the bolt forward engaging the bolt lug and the acceleration cam means which accelerates the projectile ram means forward, which moves a projectile forward, which displaces the breech block means forward to ram a projectile into the rearward end of the longitudinal bore of the barrel, the projectile ram means and the breech block are then moved rearward by their respective return springs.

2. An automatic firearm as in claim 1 wherein said forwardly displaceable breech block means comprises a gas check ball valve.

3. An automatic firearm as in claim 1 wherein said acceleration cam means comprises a lever having two ends and at least one engagement surface between said ends, one of said ends being pivoted to said receiver, the other of said ends connected to said projectile ram means, and said engagement surface engaging said lug on said bolt means.

i t t k

Claims (3)

1. An automatic firearm comprising: a receiver; a barrel attached to said receiver, said barrel having a longitudinal bore extending from a forward end to a rearward end; a combustion chamber in said receiver, said combustion chamber having a longitudinal axis parallel to but laterally spaced from said longitudinal bore of said barrel, said combustion chamber having a propellant impact surface at a rear end thereof, and a propellant introduction port at a forward end thereof; a gas passage communicating between the rearward end of said longitudinal bore of said barrel and the rear end of said combustion chamber; forwardly displaceable breech block means at the rear end of said barrel, and return means therefOr; bolt means mounted within said combustion chamber for longitudinal reciprocation between a forward position forward of said propellant introduction port and a rearward position adjacent said propellant impact surface, said bolt means having a lug thereon; bolt driving spring means for driving said bolt means rearwardly; sear means for holding said bolt against said driving spring means; projectile loading ram means for forwardly ramming a projectile and forwardly displacing said breech block means; acceleration cam means operatively connected between said lug on said bolt means and said projectile ram means for accelerating the forward movement of the projectile ram means with respect to forward movement of said bolt; and an acceleration cam means and projectile ram means return spring; whereby upon release of the bolt by the sear the bolt-driving spring moves the bolt past the propellant introduction port picking up the propellant, the bolt then impacts the propellant against the combustion chamber end wall to initiate combustion, gases of combustion flow through the gas passage into the rear end of the longitudinal bore of the barrel thereby discharging a projectile and the gases of combustion force the bolt forward engaging the bolt lug and the acceleration cam means which accelerates the projectile ram means forward, which moves a projectile forward, which displaces the breech block means forward to ram a projectile into the rearward end of the longitudinal bore of the barrel, the projectile ram means and the breech block are then moved rearward by their respective return springs.

2. An automatic firearm as in claim 1 wherein said forwardly displaceable breech block means comprises a gas check ball valve.

3. An automatic firearm as in claim 1 wherein said acceleration cam means comprises a lever having two ends and at least one engagement surface between said ends, one of said ends being pivoted to said receiver, the other of said ends connected to said projectile ram means, and said engagement surface engaging said lug on said bolt means.

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