US3859746A

US3859746A - Device for releasing an initial electric ignition of the propellant charge of cartridges for hand firearms

Info

Publication number: US3859746A
Application number: US181276A
Authority: US
Inventors: Otto Pecksen
Original assignee: Mauser Werke AG
Current assignee: Mauser Werke AG
Priority date: 1970-10-03
Filing date: 1971-09-16
Publication date: 1975-01-14
Anticipated expiration: 1992-01-14
Also published as: DE2048743A1; NL7113149A; GB1372068A

Abstract

The device comprises a manually controlled impact producing member which operates a piezo-electric voltage generator which produces a sufficiently high voltage adapted to ignite the detonator of the propellant charge of the cartridge by conducting the generated voltage to an electrode in the detonator. The munition adapted to be ignited by the mentioned device comprises a projectile, a propellant charge, and a detonator composition arranged in a recess in one end of the propellant charge. The detonator comprises two axially aligned parts having, lockingly secured between the same, a cap-shaped electrode of conductive lacquer and having a flange engaging flush with the end face of the propellant charge.

Description

States Patent [191 [4 1 Jan. 14,1975

[ DEVICE FOR RELEASING AN INITIAL ELECTRIC IGNITION OF THE PROPELLANT CHARGE OF CARTRIDGES FOR HAND FIREARMS [75] Inventor: Otto Pecksen, Herrenalb, Germany [73] Assignee: Mauser-Werke Aktiengesellschaft,

Oberndorf/Neckar, Germany 22 Filed: Sept. 16, 1971 211 App]. No.: 181,276

[30] Foreign Application Priority Data Oct. 3, 1970 Germany 2048743 [52] US. Cl 42/84, 89/28 A, 102/46, 102/702 GA, 102/DIG. 1

[51] Int. Cl F4lc 19/12, F4lf 13/08, F42b 5/08 [58] Field of Search..... 42/84; 89/28 R, 28 A, 28 C;

102/DIG. 1, 46, 70.2 GA

[56] References Cited UNITED STATES PATENTS 3,198,074 8/1965 Perkins 42/84 3,208,181 9/1965 Calhoun et a1. 42/84 3,563,177 2/1971 Ritchey 42/84 3,608,492 9/1971 Mitchell 102/46 Primary ExaminerBenjamin A. Borchelt Assistant ExaminerC. T. Jordan Attorney, Agent, or Firm-McGlew & Tuttle [57] ABSTRACT The device comprises a manually controlled impact producing member which operates a piezo-electric voltage generator which produces a sufficiently high voltage adapted to ignite the detonator of the propel lant charge of the cartridge by conducting the gener' ated voltage to an electrode in the detonator.

The munition adapted to be ignited by the mentioned device comprises a projectile, a propellant charge, and a detonator composition arranged in a recess in one end of the propellant charge. The detonator comprises two axially aligned parts having, lockingly secured between the same, a cap-shaped electrode of conductive lacquer and having a flange engaging flush with the end face of the propellant charge.

12 Claims, 10 Drawing Figures PATENIEUJANI4|975 3859.746 sum 10$ 5 I N VEN TOR.

BY 01%? Perkse WIXQOMR PM A TTGP/VEIS DEVICE FOR RELEASING AN INITIAL ELECTRIC IGNITION OF THE PROPELLANT CHARGE OF CARTRIDGES FOR HAND FIREARMS FIELD OF THE INVENTION The invention relates to a device for the release of an initial electric ignition for the propellant charge of cartridges, particularly for automatic hand firearms and machine guns and munition adapted for the same, particularly sleeveless munition. The device comprises substantially a piezo-electric voltage generator associated with circuit components which produce a contactfree ignition of a detonator composition arranged in a cartridge propellant charge by generating the required ignition voltage upon release of a striking physical mass acting on the piezo-plates of a generator, the ignition voltage being conducted to an electrode arranged in the detonator composition.

BACKGROUND OF THE INVENTION Munitions of the conventional type in automatic band firearms and machine guns are ordinarily ignited in that a metallic primer installed in the bottom wall of the cartridge, upon actuation of the firing trigger, is acted on by a striker mass subjected to the action of a spring. The initial ignition produced in this manner leads to the burning of the propellent located in the cartridge casing. The gases produced during the burning of the propellent and acting principally on the bottom wall of the projectile drive the projectile with increasing speed from the barrel of the firearm, which imparts guidance and direction to the projectile.

Not onlyby the inertia of the striker mass but also the mechanical deformation produced by the striker upon actuating the firing trigger and other unavoidable necessary mechanical operations cause quite appreciable periods of delay prior to the release of the projectile.

It is believed to be obvious, particularly with automatic hand firearms and machine guns, that in addition to a high starting speed v,,, the cadence required by the troops in view of the sum of unavoidable delay periods could not be optimally made use of.

For preventing, or at least for reducing, such deficiencies and disadvantages, it is already known to provide machine guns, for example rapidly firing guns, with a device for the electrical ignition of the munition. The firing voltage necessary for the ignition of the munition is furnished by a voltage source, such as a battery or a transformer.

SUMMARY OF THE INVENTION In addition to a more efficient device for the release of an initial ignition, it is also an object of the invention to provide a munition to be used with the ignition device of the invention, particularly a munition of sleeveless type.

In accordance with the invention, the voltage U I 2,800 V required for the ignition of the detonator composition is reached approximately at t= 6.8 7.0 usec. after the physical mass has engaged the piezo-plates of a generator, and the ignition period up to a complete burning of the cartridge propellant charge is less than 100 psec.

According to another object of the invention, the electrical components associated with the piezoelectric voltage generator comprise essentially a conventional diode circuit with a relatively high back resistance, which upon operation of the generator effects the charging of a condenser connected in parallel to the generator.

As the function of the firearm or the firearm system is not only dependent on the ignition device, but in equal measure also on the adequate construction of the munition to be ignited by it, particular value was also placed on its proper construction. The invention, therefore, requires the use of a munition-particularly a jacketless munition-which consists essentially of a projectile, a propellent receiving the same-such as a compressed powder charge or the like-and a detonator composition, primer or the like, arranged in the end of the propellent facing away from the projectile.

In accordance with the invention, the detonator composition is constructed of multiple parts, preferably of two parts, whereby the individual parts in the longitudi nal axis of the cartridge are pressed together by interposing therebetween a cap-shaped electrode which is positively locked into the propellent.

In addition, in accordance with the invention, a flange of the electrode is disposed flush against the surface of the propellent facing away from the projectile.

In order to insure a safe and positive contact of the electrode-even under extreme conditions-between the two detonator compositions, the electrode is made preferably of conductive lacquer or the like.

Furthermore, the invention provides also a definite dimensioning of the two parts of the detonator composition in which the first part of the detonator composition disposed next to the projectile with respect to the second part of the detonator composition has a height or axial length of approximately a ratio of two-thirds to one-third.

Finally, the invention indicates to an expert that the recess in the propellant used for the reception of the parts of the detonator composition, as well as the electrode, is made so deep that it providesin addition to the reception of an additional paper covering or the likestill a space having an axial dimension of the order of approximately 0.1 0.12 mm for the transfer of the ignition voltage U from the generator to the electrode.

The advantages of the invention which are believed to be obvious and convincing are as follows:

The ignition device in its electrical and mechanical construction, according to the invention, is simple and reliable in operation. Beyond this, the device requires little space, which to a particular degree makes it especially adaptable to be utilized in firearms or firearm systems.

The generation of the ignition voltage takes place in a relatively simple, and above all in a wear-resistant, manner by employing a relatively small physical mass which strikes the piezo-plates with a suitable speed, and it is possible to generate a voltage peak of the order of size of about 3,000 V within a rise time of less than 10 usec. This voltage peak is sufficient to insure a reliable electric initial ignition of the detonator composition.

A particular advantage of employing this type of ignition device and the correspondingly formed munition resides in a noticeable reduction in the ignition delay periods, as the detonator composition-on account of its height or axial length and the sharp rise in the ignition voltage-burns substantially more rapidly than in the conventional ignition methods, the latter of which require a relatively large time period for bringing about the deformation of the metallic primer when the firing pin strikes the primer housing and which also operate with lower ignition voltages at relatively high currents. Of substantial advantage is also that with jacketless munition, the detonator composition may be provided in simple manner with an electrode of conductive lacquer or the like. This again has the advantage that the detonator composition requires no mechanical contact at all through the ignition voltage, so that the ignition takes place not only without contact, but also the tolerance of the munition may be selected more liberally.

A further decisive advantage of the invention, when compared with the known electric primers of metal, consists in that the detonator composition does not lie between two electrodes which have a capacity disposed in parallel to the resistance of the detonator composition of about 30 60 pF. As this capacity is capable of being charged, it is the larger, the larger is the resistance of the detonator composition. This mens that, with the known electric primers, the danger increases on account of higher voltages. It is therefore necessary with the known electric primers in the first place to keep the electric resistance of the primer small, and in the second place to short-circuit the electrodes by means of metal foils. Apart from the fact that, with the pressed detonator composition of the jacketless munition, according to the invention, only one electrode is required, there is also no capacity connected in parallel to the detonator-composition resistance. The munition to be ignited with the ignition device of the invention is additionally far less dangerous and can readily be stored in a warehouse. Of course, on account of these especially positive characteristics, also the packing of the munition according to the invention is more simple and accordingly less expensive.

Still another important advantage of the invention is an increase in the reliability of accuracy of fire. The deviations in target or aim with the firing when using the ignition device according to the invention, are far less than with the conventional release by means of a firing pin system.

For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate by way of example an embodiment of the invention.

IN THE DRAWINGS:

FIG. 1 illustrates diagrammatically and in section an ignition device in accordance with the invention.

FIG. 2 shows a diagram in which the course of the voltage U V is illustrated in relation to the time t 11sec.

FIG. 3 is a diagrammatic illustration of a part of jacketless munition.

FIG. 4 is a diagrammatic illustration in section of a detonator composition pressed into the compressed powder charge according to FIG. 3 and also iliustraates the associated counterelectrode.

FIG. 5 illustrates a circuit arrangement of one embodiment of the invention.

FIG. 6 illustrates the graph of the voltage course of the embodiment of FIG. 5.

FIGS. 7 and 9 illustrate additional circuit arrangements of the invention; and

FIGS. 8 and 10 illustrate the voltage courses of the modifications shown in the FIGS. 7 and 9, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the rear of a not-illustrated cartridge chamber of an automatic hand firearm or machine gun is arranged, according to FIG. 1, a tubular housing 1 coaxially to the axis of the bore. This housing 1 takes the place of a mechanically operating firing pin device and is used for receiving, on the cartridge chamber side, an anvil 2, which is provided with spaced

parallel bores

2a, 2b. The anvil 2 is followed by the superimposed piezoplates 3a connected in series so as to form a voltage generator 3. This voltage generator 3 is connected with not illustrated compnents'comprising substantially a diode circuit, known per se, with a relatively high back resistance as well as of a correspondingly dimensioned condenser connected in parallel with the generator 3.

The-last piezo-plate 3a facing away from the anvil 2 is in suitable manner provided with a metallic abutment counterpiece 4 on which an impact member 5 engages strikingly for causing ignition. The impact member 5 is provided with a reduced axial extension 5a, which partially extends through the lower end of the tubular housing 1. Within the housing 1 the reduced extension 5a is coaxially surrounded by a helical impact spring 6. The end of the extension 5a projecting from the housing 1 has an annular groove 5b in which a lug 7a of a tension-and-release lever 7 engages, which latter is pivotally supported between its ends at8 outside the housing 1.

For the release of an initial ignition in the detonator composition 11, which will be described further in detail herebelow, the tension-and-release lever is pivotally actuated in clockwise direction as indicated by the arrow in FIG. 1. When this is done, the lung 7a leaves the annular groove 5b and the physical mass formed by the impact member 5 and its extension 5a is accelerated by the pressure of the pretensioned impact spring 6 strikingly toward the cartridge chamber. During this operation, the impact member 5 encounters the counterpiece 4 connected with the piezo-plates 3a. The voltage induced during this operation in the piezo-plates 3a charges a condenser. The impact taking place within 1 6.8 7.0 asec. of the voltage peak produced by the mass of the impact member 5 and its extension 5a of U 2,800 V ignites then the detonator composition 11.

The diagram illustrated in FIG. 2 indicates the course of the voltage U just described as a function of time I in 11sec.

FIG. 3 illustrates a part of a jacketless munition. The projectile 9 is pressed into the propellent 10 consisting, for example, of a compressed powder charge. In the lower end 10a of the compressed charge 10 facing away from the projectile 9 is arranged a central recess 10b for the reception of the detonator composition indicated in its entirety by 11, as well as of the electrode 12 and the paper covering 13 or the like which usually is required.

The last mentioned details are illustrated once more in FIG. 4 on an enlarged scale, wherein particularly the cap-shaped electrode 12 is shown which consists of conductive lacquer or the like. An outwardly extending flange on the cap-shaped electrode 12 engages flush the bottom or end face of the compressed charge 10. The detonator composition comprises two parts lla,

11b, while the paper covering 13 is spaced from the lower end of the space in the cap electrode 12 a distance 14 of the order of size of about 0.1 0.2 mm. This distance is sufficient for the transfer of the ignition voltage U, from the generator 3 to the electrode 12.

According to the circuit arrangement of FIG. 5, the voltage generator 3 acts directly on the detonator composition 11 of the sleeveless munition. The impact force P which is produced by the spring 6 causes the generator to generate a very high voltage U, which is higher than 3,000 V. This voltage is generated in the usec. range as indicated in FIG. 6. As a result of the high volltage, the spark coming from the electrode 15 penetrates the air gap 14 and the detonator composition lll up to the counterelectrode 12. The spark produces such an amount of heat that the entire detonator composition 11 is ignited. This has the advantage that the detonator composition 11 of the sleeveless munition is ignited contactless. The layer between the electrode 15 and the counterelectrode 12 has to be of such a high ohmic value that the produced spark develops sufficient heat from the electrode to the counter electrode so as to cause an ignition of the detonator composition l1.

FIGS. 7 and 9 illustrate circuit arrangements employing rectifiers and condensers in addition to the circuitry shown in FIG. 5, with FIGS. 8 and 10 illustrating the voltage courses of the embodiments of the invention shown in FIGS. 7 and 9, respectively.

Referring to FIG. 7, a rectifier 26 is arranged between the detonator composition 11 and the voltage generator 3. After the condenser 27 has been charged by a high voltage the same operation takes place as previously described in connection with the FIGS. 5 and 6.

FIG. 8 illustrates a graph of the charging course of the condenser 27.

FIG. 9 illustrates a circuit employing a full wave rectifier 28 and a condenser 29, and further illustrates the impact force P and the impact relief -P. Condenser 29 is charged to a double value as compared with the condenser 27 of FIG. 7, so that FIG. 9 represents a condenser voltage doubling circuit.

The charging characteristic of the condenser 9, resulting in charging thereof to double the value of the condenser 27 of FIG. 9, is illustrated in FIG. 10.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. In a firearm constructed and arranged for firing cartridges each including a projectile, a propellant charge for the projectile, a detonator charge, for detonating the propellant charge, and said detonator charge having an electrode therein: a device for electrically igniting the detonator charge by applying a high potential voltage to such electrode comprising, in combination, a tubular housing; an anvil at one end of said housing, a piezo-electric voltage generator mounted in said housing and having one end engaging said anvil; manually releasable impact-producingmeans engaging the opposite end of said piezo-electric voltage generator and having a portion projecting from said housing; means engaging said projecting portion of said impactproducing means and operable to tension and release said impact-producing means to impact said piezo' electric voltage generator; and circuit means connecting said piezo-electric voltage generator to the electrode in the detonator charge of a cartridge in said firearm; said piezo-electric voltage generator, when subjected to said impact by said impact-producing means, generating, in substantially 6.8 to 7 microseconds after impact, a voltage of substantially 2,800 Volts applied to said circuit means and sufficient to ignite said detonator charge to burn in a period of not more than microseconds to detonate said propellant charge.

2. Device according to claim 1, in which each cartridge comprises a projectile, a propellant charge of compressed powder for said projectile, and a detonator charge arranged in the end of the propellant charge facing away from the porjectile, said detonator charge consisting of several parts arranged in axial alignment, and a cap-shaped electrode between two of said parts and pressed lockingly into said propellant charge.

3. Device according to claim 1, in which said electrode is provided with a flange disposed flat against the end face of the propellant charge facing away from the projectile.

4. Device according to claim 1, in which said electrode consists of conductive lacquer.

5. Device according to claim 1 in which said detonator charge comprises two parts of which the first part closest to the projectile has with respect to the second part an axial dimension of approximately a ratio of twothirds one-third.

6. Device according to claim 1, in which the propellant charge is provided with a recess for receiving the detonator charge parts as well as said electrode, said recess being dimensioned so deep that it permits, in addition to the insertion therein of an additional paper cover, the formation of a space having an axial dimension of about 0.1 0.12 mm for the transfer of the ignition voltage from the piezo-electric generator to the electrode.

7. Device according to claim 1, in which said circuit means is a diode circuit having a relatively high back resistance; said circuit being connected with said piezoelectric generator; and a condenser connected in parallel with said generator in said diode circuit, said diode circuit charging said condenser.

8. Device according to claim l, in which said circuit means comprises a voltage doubler circuit including a full wave rectifier having input terminals connected in parallel to said piezo-electric generator and a condenser connected across its output terminals; said full wave rectifier charging said condenser to double the value of the voltage output of said piezo-electric generator; one output terminal of said full wave rectifier being connected to said electrode and the other output terminal thereof defining, with said electrode, an air gap.

9. Device according to claim 8 characterized in that said electrode arranged in the detonator-charge is substantially cap-shaped.

10. Device according to claim 9 characterized in that a cap flange of said electrode lies in a plane on the surface of said propellant-charge facing away from the projectile.

11. Device according to claim 10 characterized in that said electrode consists of conducting lacquer.

12. Device according to claim 8 characterized in that the air gap for the transfer of the ignition voltage to said electrode is approximately 0.1 to 0.12 mm.

Claims

1. In a firearm constructed and arranged for firing cartridges each including a projectile, a propellant charge for the projectile, a detonator charge, for detonating the propellant charge, and said detonator charge having an electrode therein: a device for electrically igniting the detonator charge by applying a high potential voltage to such electrode comprising, in combination, a tubular housing; an anvil at one end of said housing, a piezo-electric voltage generator mounted in said housing and having one end engaging said anvil; manually releasable impact-producing means engaging the opposite end of said piezo-electric voltage generator and having a portion projecting from said housing; means engaging said projecting portion of said impact-producing means and operable to tension and release said impact-producing means to impact said piezoelectric voltage generator; and circuit means connecting said piezo-electric voltage generator to the electrode in the detonator charge of a cartridge in said firearm; said piezoelectric voltage generator, when subjected to said impact by said impact-producing means, generating, in substantially 6.8 to 7 microseconds after impact, a voltage of substantially 2,800 Volts applied to said circuit means and sufficient to ignite said detonator charge to burn in a period of not more than 100 microseconds to detonate said propellant charge.

5. Device according to claim 1 in which said detonator charge comprises two parts of which the first part closest to the projectile has with respect to the second part an axial dimension of approximately a ratio of two-thirds : one-third.

6. DeVice according to claim 1, in which the propellant charge is provided with a recess for receiving the detonator charge parts as well as said electrode, said recess being dimensioned so deep that it permits, in addition to the insertion therein of an additional paper cover, the formation of a space having an axial dimension of about 0.1 - 0.12 mm for the transfer of the ignition voltage from the piezo-electric generator to the electrode.

7. Device according to claim 1, in which said circuit means is a diode circuit having a relatively high back resistance; said circuit being connected with said piezo-electric generator; and a condenser connected in parallel with said generator in said diode circuit, said diode circuit charging said condenser.

8. Device according to claim 1, in which said circuit means comprises a voltage doubler circuit including a full wave rectifier having input terminals connected in parallel to said piezo-electric generator and a condenser connected across its output terminals; said full wave rectifier charging said condenser to double the value of the voltage output of said piezo-electric generator; one output terminal of said full wave rectifier being connected to said electrode and the other output terminal thereof defining, with said electrode, an air gap.