Historical Document · 1978
H&K's patent on the G11's recoiling-assembly small arm (German priority 8 October 1975, P 25 44 995; issued 14 March 1978). The Hyper-Burst Mechanisms dive cites it for how the G11 fires a three-round burst before the recoil reaches the shooter.
United States Patent [191 [11] 4,078,327 Miiller et al. [45] Mar. 14, 1978 [54] AUTOMATIC OR SEMI-AUTOMATIC SMALL ARM [56] [75] Inventors: Tilo Miiller, Oberndorf-Lindenhof; Dieter Ketterer, Oberndorf, both of 645,932 3,859,746 Germany 3/1900 I/ 1975 Beck et al. ............................. .. 42/84 Pecksen .................................. .. 42/84 FOREIGN PATENT DOCUMENTS [73] Assignee: Heckler & Koch GmbH, Oberndorf, Germany 619,756 ‘ 3/1949 United Kingdom .................... .. 89/7 Primary Examiner—Stephen C. Bentley Attorney, Agent, or Firm-Spencer & Kaye [21] Appl. N0.: 730,256 Oct. 6, 1976 [22] Filed: Foreign Application Priority Data [30] Oct. 8, 1975 References Cited U.S. PATENT DOCUMENTS [5 7] ABSTRACT A weapon includes a receiver which de?nes a dust-tight and water~tight space accommodating a barrel and a Germany ........................... .. 2544995 [51] [52] US. Cl. ..................................... .. 42/71 R; 42/84; [58] Field of Search ............ .. 89/1 R, 1 E, 7; 42/1 R, Int. Cl.2 ............................................ .. F41D 11/18 89/1 E 42/71 R, 84 bolt assembly slidably carried by the barrel at the breech thereof. An ignition device is arranged within the space de?ned by the receiver for igniting, at prede termined times, combustible gases accumulating in that space. 18 Claims, 2 Drawing Figures U.S. Patent March 14, 1978 Sheet10f2 4,078,327 U.S. Patent Marclzh 14, 1978 1 \\\\\\\\v\\\ \\\\\ Sheet2 on 4,078,327 1 4,078,327 AUTOMATIC OR SEMI-AUTOMATIC SMALL ARM BACKGROUND OF THE INVENTION The present invention relates to a safety arrangement in a weapon, such as an automatic or semi-automatic small arm. The invention may ?nd particular applica tion in a ri?e for ?ring caseless cartridges, having a bolt assembly which is movably mounted in the longitudinal direction of the ri?e and movable relative to a barrel, 2 One advantage of a small arm designed in accordance with the present invention is that the receiver does not need an additional opening, and ‘yet the danger of exces sive overpressures is nevertheless avoided. By means of frequent ignition by the ignition device, minor quanti ties of ignitable gas mixture which may accumulate are burned before the volume of gas is large enough to result in dangerous pressure when combusted. Espe cially if, in a preferred embodiment of the invention, the ignition means is actuated as a. function of the ?ring sequence, it is possible to ensure that even very minor further having an ammunition magazine, a cartridge quantities of combustible mixture are ignited, and thus feed mechanism and a trigger mechanism. The fully safely burned. Since an egress of gases from the barrel operational weapon system is contained in a dust and into the receiver is unavoidable and it is not feasible to 15 eliminate the possibility that, ?rst, an ignitable gas/air water-tight receiver designed as a stock. mixture ratio can result, and, second, mechanically A small arm of this type is disclosed in German Laid generated sparks or burning powder particles can be Open Patent application (Offenlegungsschrift) No. 23 present, regularly combusting the ignitable gas mixture 26 525.0. In this weapon, the entire, fully operation represents a possibility of eliminating overloads and weapon system is shiftably mounted in a receiver de signed as a stock. The slidability of the entire system 20 damage to the weapon, in particular the receiver. By actuating the ignition means as a function of the ?ring provides accuracy advantages by eliminating or reduc sequence, for example after every shot or burst, it is ing recoil to a minimum during a limited number of shots or during a burst. This known small arm is also possible to ensure that the gases are ignited at the lower advantageous in that is satisi?es more stringent de mands, because the weapon system is located within the receiver and because the receiver is sealed against the external effects of dust and water. The only opening remaining is the muzzle. The receiver is only dust and ignition mixture limit, causing the combustion to be relatively quiet and free of high pressure peaks. This gases are formed which contain combustible gas resi oxygen if at all, and no air can penetrate into the re ceiver from the outside, as an overpressure prevails in the receiver. Air can penetrate only if no shot is ?red for a certain length of time, and thus overpressure in the avoids endangering either shooter or weapon. In addi-_ tion, a surprising advantage can be seen in the fact that after only a few ignitions, the mixture is no longer ignit able, as the percentage of oxygen has become too low. water-tight, but not gas-tight. It is a known fact that when a shot is ?red, propellant 30 The gases flowing in from the barrel contain too little dues, in particular CO. When the bolt assembly is opened, there may still be considerable pressure in the barrel, which causes the residual gases to flow out at the chamber end instead of toward the muzzle. If the cham ber, like thebolt assembly, is located in a sealed re receiver relative to the atmosphere has been completely eliminated. However, an actuation of the ignition means after the ?rst shot or burst, causes the gas to be ignited, ceiver, combustible gas residues can also ?ow into the as described above, as soon as it is ignitable, thereby receiver. Although, as a result, a pressure buildup takes . gradually reducing the percentage of oxygen so greatly place in the receiver, the upper pressure limit remains 40 that the gas in the receiver is no longer ignitable. far below the rupturing pressure of the receiver, even if The ignition means can be of widely varying design large numbers of shots are ?red, since the receiver is not and arrangement. In a preferred embodiment of the sealed gas-tight. It has been found, however, that when invention, in which the small arm is designed as a gas the gas mixture located in the receiver is ignited, for operated weapon, the ignition means are arranged in the example, as a result of the ejection of powder particles 45 area between the bolt assembly and a gas piston of the which are still burning, the pressure in the receiver can increase considerably, which should be avoided. This increase in pressure caused by ignition of the gas mix ture contained in the receiver cannot be controlled with an overpressure valve, as the rate of increase of the pressure is very great and the cross-sectional area avail able for an overpressure valve is relatively small. In addition, an overpressure valve of this type would be a source of malfunctions as a result of a failure to seal, caused, for example, by sand. SUMMARY OF THE INVENTION It is an object of the present invention to design a weapon, particularly a small arm of the type described gas-operated action. It is preferable for the ignition means to be actuated by the bolt assembly or the bolt assembly drive (action). This permits the ignition means to be actuated as a function of the ?ring sequence in a very simple manner. The ignition means may comprise a battery for sup plying voltage to a spark gap by means of a capacitor charging circuit or a coil with contact breaker. The use of batteries, however, is problematic if the small arm is 55 an army weapon, as in this case the weapon is required to operate dependably even after many years of storage; yet, no batteries are available which can retain their charge for a storage period of such length. It is also conceivable to cause ignition by means of mechanically at the outset in such a manner that no excessively high 60 generated sparks, for example, by means of a flint as in overpressure can occur in the receiver, even if residual a cigarette lighter. However, such a design of the igni propellant gases are ignited. This object and others to become apparent as the speci?cation progresses, are achieved by the invention, tion means would result in the disadvantage that the spark energy would be relatively low and the reliability of operation and ignition would not be sufficiently high. according to which, briefly stated, the weapon includes 65 For this reason, in a preferred embodiment of the inven an ignition device arranged within a space de?ned by tion, the ignition means comprise at least one piezoelec the receiver for igniting, at predetermined times, com tric crystal, which is connected with a spark gap in an bustible gases accumulating in that space. electrically conductive manner and which is subjected 3 4,078,327 to a mechanical impact by a percussive member for generating a charge which produces a spark capable of causing ignition. With ignition means of this design, the small arm according to the present invention can be 4 crystals by a spring. As a result of its kinetic energy, the ram transmits a sufficient pulse to the piezoelectric crystal(s); the spring permits the gas piston to continue to travel and move relative to the force limiter. It is also stored inde?nitely, which means that it is readily capa possible to use buffer means of the gas-operated action ble of immediate service, even after years of storage. In addition, ignition means of this type are of simple de as the percussive member, as these means are present in any event. In general, however, it is expedient to use a separate force limiter, as it can be provided with little effort and expense. sign, and therefore dependable. Further, ignition means of this design can be manufactured economically. In a preferred embodiment of the ignition means, there are two piezoelectric crystals, connected one opposite the other (back-to-back) electrically and one behind the other mechanically; an insulated lead ex tends to a ?rst pole of a spark gap from an electrode on those end surfaces of the two crystals which face one another. A second pole of the spark gap and the two end surfaces of the two crystals facing away from one another maybe connected by ground. The use of two piezoelectric crystals increases both the electric output and the reliability of the weapon if the arrangement is dimensioned in such a manner that the spark generated by one crystal is still sufficient for ignition. Even if one of the two crystals should fail, e.g. as a result of a short circuit, the other will still always provide dependable ignition. An advantage of an electrical ignition process of this type is that the zone where the electrical energy is gen erated and the location of the electrical discharge, i.e. the location of the spark gap, can be freely selected, since it is suf?cient to lead an insulated wire to the spark gap from the energy converter generating the electrical energy. It is therefore possible to arrange the spark gap in an optimum position for igniting the gas mixture, BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal sectional view of a small arm incorporating the invention. FIG. 2 is a schematic longitudinal sectional view of a preferred embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, there is shown a schematic representation of a practical example of an automatic ri?e, having a weapon system contained in the space 1a of an essentially dust and water-tight receiver 1. The weapon system comprises a barrel 2, a cylindrical bolt assembly 3, a magazine 4, arranged parallel to the bar 25 rel, a cartridge feed mechanism 5 and a housing 7 with a portion of the trigger mechanism, whose trigger 8 extends to the outside through the receiver 1. A pistol grip 6, including a trigger guard 9 surrounding trigger 8, is attached to the receiver 1 in the vicinity of the trigger 8. Attached at the top of receiver 1, opposite piston grip 6, is a carrying handle 10 with sights 11. The magazine 4 is arranged above the barrel, with a cocking lever 12 provided outside the receiver, beneath barrel 2, without having to take the location of the energy con in the area of the muzzle; an actuating member 13 ex verter into consideration. In a preferred embodiment of 35 tends from cocking lever 12 through the receiver in a the invention, the spark gap is therefore arranged, for sealed manner, to the inside and to cylindrical bolt as example, in the vicinity of the bolt assembly. This is the sembly 3. This weapon system which is disclosed in the above-mentioned German Laid-Open application No. 23 26 525.0, is capable of ?ring a plurality of shots will be reached here ?rst. If, in addition, the point in 40 (burst) during the rearward travel of the weapon system zone in which the highest gas concentrations are to be expected, so that the limit of an ignitable gas mixture time at which the spark is generated is expediently se from a forward limit position to a rearward limit posi lected, which is very simple to achieve, the gas mixture tion. Upon ?ring each shot of the burst, the bolt assem ignites long before a stoichiometric mixture ratio is bly 3, driven by the gas piston 3 of the gas-operated reached. After only a few ignition cycles, the mixture action and a return spring, executes a reciprocating contains so little air that it can no longer be ignited. If 45 motion with respect to the barrel 2. The bolt assembly the percentages of CH, and H2, which are also present, 3 may be essentially of the structure, which is disclosed although in minor quantities, are ignored and if only the CO, which represents the major percentage of combus in the above-mentioned German Laid-Open application No. 23 26 525.0 or as disclosed in the German Laid tible gas, is taken into consideration, the limit at which Open application No. 24 13 615.0. Further, the weapon the mixture can no longer be ignited is reached at a 50 is an automatic ri?e for ?ring caseless cartridges. This percentage of air of less than 26%. eliminates the need for a case ejection port, which The percussive member performing the mechanical blow against the piezoelectric crystal or piezoelectric crystals can be of varying design and arrangement. For would result in sealing problems. In addition, the space between the cylindrical bolt assembly 3 and a butt stock 14, which closes the rear of receiver 1, can be utilized example, it can be designed as a hammer which is 55 for the recoil of the weapon system if caseless ammuni tripped at a given point in time, for example, as a func tion is ?red. If case-type ammunition or ammunition tion of the actuation of the bolt assembly. Arming with a case head were ?red, the space could be used for (cocking) of the hammer, too, can be effected as a func tion of the actuation of the bolt assembly. The percus collecting the empty cases or case heads. The gas piston 15 has a downwardly directed projec sive member can further be designed as a mass which is 60 tion 16 containing a bore hole extending parallel to the moved directly by the action. In a preferred embodi barrel. A ram 17 with a head 18 is longitudinally slid ment of the invention, in which the small arm is de signed as a gas-operated weapon, the percussive mem ber is designed as a force limiter, which can be moved ably guided in the bore hole. A helical compression spring 19 surrounding the shank of ram 17 is arranged together with the gas piston of the gas-operated action. The force limiter comprises a longitudinally slidable ram, whose head is oriented towards the piezoelectric crystals and which is forced toward the piezoelectric between projection 16 and head 18 to urge the ram 17 in the direction of butt stock 14, causing a collar 20 ar ranged on ram 17, at the opposite end of head 18, to come into a contacting relationship with the end surface of projection 16. 5 4,078,327 6 Piezoelectric ignition means 21 are arranged between scribed. In particular, individual characteristics of the trigger assembly housing 7 and the force limiter formed present invention can be used either individually or in of the ram 17 and helical compression spring 19. Turning now to FIG. 2, the piezoelectric ignition means 21 comprise a housing block 22 which is attached to the outside of the housing 7 and which contains a combination. The salient feature of the present inven— tion is that a spark is repeatedly generated in an en closed space, into which gas containing ignitable com ponents is introduced in batches; the spark causes the longitudinal hole extending parallel to barrel 2. It is gas mixture to ignite as soon as it reaches the limit of noted that the housing 7, as part of the above-discussed inflammability. This maintains the pressure increase weapon system, moves with the barrel 2 as a unit. The which occurs in connection with combustion of the gas mixture relatively low, on the one hand, and provides a mixture which is no longer ?ammable after a few igni_ tion processes because of a lack of oxygen, on the other hand. This prevents a damaging increase in pressure in the enclosed space. longitudinal hole of the block 22 is designed as a blind hole which opens in the direction of head 18 of ram 17, but which is closed off by means of a pressure pin 23 is adjoined by a metal insert 24, which, in turn, is adjoined by a piezoelectric crystal 25. The latter is adjoined by a central electrode 26, which, in turn, is adjoined by a piezoelectric crystal 27. A further metal insert 28 is arranged between piezoelectric crystal 27 and the base of the blind hole. Piezoelectric crystals 25 and 27 are arranged in such a manner that when a force acts on the What is claimed is: 1. In a safety arrangement for a weapon to prevent accidental ignition of potentially dangerous quantities of combustible gases generated during ?ring of the weapon and accumulating therein; the weapon includ pressure pin 23, identical charges are formed on those 20 ing a dust-tight and water-tight receiver; a barrel; a bolt end surfaces of piezoelectric crystals 25 and 27 which assembly slidably carried by the barrel at the breech end face the central electrode 26 and are in engagement therewith. thereof; the bolt assembly being arranged for longitudi nal recriprocation with respect to the barrel when a The housing block 22 comprises a body of insulating shot is ?red; the barrel and the bolt assembly being material, containing a further opening 29, which ex 25 accommodated within the receiver; a space being sur tends generally tangential to the axis of barrel 2 and rounded and de?ned by the receiver and being situated which is in continuous communication with the space externally of the barrel and the bolt assembly; the im enclosed by the receiver 1. Two discharge electrodes 30 provement comprising ignition means disposed within and 31 extend into opening 29. The electrode 30 is elec said space and being in operative communication there trically connected with the two metal inserts 24 and 28, 30 with for igniting, at predetermined times, said combusti while the electrode 31 is electrically connected with the ble gases ?lling said space. central electrode 26. The discharge electrodes 30 and 2. A safety arrangement for a weapon as de?ned in 31, which are located one opposite the other with a claim 1, wherein said ignition means includes actuating given clearance, de?ne a spark gap, across which the means for igniting the combustible gases in said receiver charges generated on piezoelectric crystals 25 and 27 35 as a function of weapon ?ring. are discharged by drawing a spark. 3. A safety arrangement for a weapon as de?ned in When a shot is ?red, the resulting gas pressure moves claim 2, wherein said actuating means is arranged for the gas piston 15 toward the cylindrical bolt assembly 3. operation by a component of the weapon upon ?ring During the course of this motion, head 18 of ram 17 each shot. strikes the pressure pin 23 which transmits a force -— that is proportional to the delay of ram 17 -— to the column of piezoelectric crystals. The resulting charges 4-. A safety arrangement for a weapon as de?ned in claim 2, wherein said actuating means is arranged for operation by a component of the weapon upon ?ring a on the end surfaces of piezoelectric crystals 25 and 27 plurality of shots. are equalized by a spark between discharge electrodes 5. A safety arrangement for a weapon as de?ned in 30 and 31, which ignites any ignitable gas mixture 45 claim 2, wherein said actuating means includes a mecha which is present. It is thus seen that in this weapon, nism coupled to a weapon component executing a dis which, as explained above, is capable of ?ring a burst placement caused by weapon ?ring. while the barrel travels rearwardly, the ignition means 6. A safety arrangement for a weapon as de?ned in is actuated subsequent to the ?ring of each shot, since claim 5, wherein said weapon component is said bolt the percussive member 17, 18 is carried by the gas pis 50 assembly. ton 15 which executes separate reciprocating move ments upon the ?ring of each shot of the burst. If it is desired that the ignition means operate not after each 7. A safety arrangement for a weapon as de?ned in inner face of the butt 14, or vice versa as is shown in ing said bolt assembly after ?ring each shot, said claim 6, wherein said mechanism is arranged for actua tion by said bolt assembly at a moment when said bolt shot but only after each burst of shots, the percussive assembly is in an open position with respect to the member is secured, for example, to the rearward end of 55 breech. the barrel, or of the bolt assembly resp., whereas the 8. A safety arrangement for a weapon as de?ned in igniting device proper is secured, for example, to the claim 5, including an action for longitudinally displac dotted lines in FIG. 1. After the last shot of the burst is weapon component being said action. ?red, the barrel and the bolt will have travelled suf? 60 9. A safety arrangement for a weapon as de?ned in ciently rearwardly to cause actuation (by the percussive claim 8, wherein said action includes a gas-operated member carried thereby) of the igniting device. piston, said mechanism being coupled to said piston. Obviously, many modi?cations and variations of the 10. A safety arrangement for a weapon as de?ned in present invention are possible in the light of the above claim 8, wherein said mechanism is arranged for actua teachings without departing from the scope of the pres 65 tion by said action at a moment when said bolt assembly ent invention. It should therefore be understood that, is in an open position with respect to the breech. within the scope of the appended claims, the invention 11. A safety arrangement for a weapon as de?ned in may be practiced otherwise than as speci?cally de claim 9, wherein said ignition means is disposed in the 7 4,078,327 piston. 12. A safety arrangement for a weapon as de?ned in claim 2, wherein said ignition means includes a piezo electric crystal, a spark gap and conductor means elec 8 17. A weapon as de?ned in claim 1, wherein said ignition means includes a. ?rst and second piezoelectric crystals each having opposite ?rst and second faces; said ?rst faces being zone between said bolt assembly and said gas-operated 5 oriented towards one another and said second faces being oriented away from one another; b. a central electrode disposed between said crystals and electrically connected to said ?rst faces; trically connecting sid crystal with said spark gap; said actuating means including a percussive member ar ranged for imparting a mechanical blow on said crystal 0. a spark gap formed of spaced discharge electrodes; (1. ?rst conductor means electrically connecting said central electrode with one of said discharge elec for generating a voltage; said voltage being applied by said conductor means to said spark gap for drawing an igniting spark thereacross. trodes; 13. A safety arrangement for a weapon as de?ned in e. second conductor means electrically connecting claim 12, wherein said spark gap is disposed in the vicin ity of said bolt assembly. 15 said second faces of said piezoelectric crystals with another one of said discharge electrodes; and f. a movably mounted percussive member for impart ing, at least indirectly, a mechanical blow to said 14. A safety arrangement for a weapon as de?ned in claim 12, including a gas-operated action for longitudi nally displacing said bolt assembly after each shot is ?red, a buffer mechanism forming part of said gas piezoelectric crystals for generating opposite po~ larities on said ?rst and second faces of said piezo operated action, said buffer mechanism being arranged 20 to constitute said percussive member. 15. A safety arrangement for a weapon as de?ned in claim 12, including a gas-operated action having a gas electric crystals for applying a spark discharge voltage across said discharge electrodes; said pi ezoelectric crystals being arranged one behind the other when viewed in the direction of movement of said percussive member. operated piston for longitudinally displacing said bolt 18. A safety arrangement for a weapon as de?ned in assembly after ?ring each shot, a force limiter attached 25 claim 17, including a gas-operated action having a gas to said piston and movable therewith as a unit, said operated piston for longitudinally displacing said bolt force limiter constituting said percussive member. assembly after each shot is ?red, said percussive mem 16. A safety arrangement for a weapon as de?ned in ber being carried by said gas-operated piston; said barrel claim 15, wherein said force limiter comprises a ram 30 being movably supported in said receiver for executing arranged on said piston for displacement with respect to a longitudinal displacement upon weapon ?ring; a hous said piston in the direction of its path of travel, said ram ing block accommodating said piezoelectric crystals, having an impacting head oriented towards said piezo said central electrode, said spark gap and said ?rst and electric crystal; said force limiter further including a second conductor means; said housing block being ar spring urging said ram in the direction of said piezoelec 35 ranged for movement with said barrel as a unit. * I‘! it it Ill tric crystal. 45 50 55 65