US3861312A

US3861312A - Ignition device having an ignition sequence including fuse elements for preventing an unintentional release

Info

Publication number: US3861312A
Application number: US378587A
Authority: US
Inventors: Manfred Held; Johann Spies
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1972-07-15
Filing date: 1973-07-12
Publication date: 1975-01-21
Anticipated expiration: 1992-01-21
Also published as: DE2234849A1; DE2234849B2; FR2193191A1; IT992624B; FR2193191B1; DE2234849C3; GB1433377A

Abstract

An ignition device having an ignition sequence including fuse elements preventing an unintentional release of the pyrotechnic composition. The ignition sequence is fed with voltage by a turbine generator upon reaching a predetermined rotation speed. The turbine generator is supported movably as a part of the ignition sequence in relation to a fuse element and is movable into its position which unlocks the ignition sequence to a pyrotechnic composition which is fed by the generator voltage through a threshold gate member.

Description

Unite Held et al.

tates Jan. 21, 1975 IGNITION DEVICE HAVING AN IGNITION SEQUENCE INCLUDING FUSE ELEMENTS FOR PREVENTING AN UNINTENTIONAL RELEASE [75] Inventors: Manfred Held, Kuhbach; Johann Spies, Pfaffenhofen, both of Germany [73] Assignee: Messerschmitt-Bolkow-Blohm GmbH, Munich, Germany 22 Filed: July 12, 1973 21 Appl. No.: 378,587

[30] Foreign Application Priority Data July 15, 1972 Germany 223484 [52] U.S. Cl. l02/70.2 G

[51] Int. Cl F42c 11/00, F42c 15/4 [58] Field of Search 102/70.2 G, 70.2 R, 81 102/81.

[56] References Cited UNITED STATES PATENTS 2,680,407 6/1954 Clark 102/702 G 2,795,]90 6/1957 Harmon et al 1. 102/702 G 2,985,105 5/l96l Rabinow et al 102/702 G 3,140,661 7/1964 Clarke 102/702 G 3,377,954 4/[968 Rabinow 102/702 R 3,401,635 9/1968 Rabinow l02/70.2 R

Primary Examiner-Benjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-Woodhams, Blanchard and Flynn [5 7] ABSTRACT An ignition device having an ignition sequence including fuse elements preventing an unintentional release of the pyrotechnic composition. The ignition sequence is fed with voltage by a turbine generator upon reaching a predetermined rotation speed. The turbine generator is supported movably as a part of the ignition sequence in relation to a fuse element and is movable into its position which unlocks the ignition sequence to a pyrotechnic composition which is fed by the generator voltage through a threshold. gate member.

8 Claims, 7 Drawing Figures PAIEMEB 1 1915 3.861.312

SHEET 1 BF 3 PATENTEB JAN 21 I875 SHEET 3 0F 3 IGNITION DEVICE HAVING AN IGNITION SEQUENCE INCLUDING FUSE ELEMENTS FOR PREVENTING AN UNINTENTIONAL RELEASE The invention relates to an ignition device having an ignition sequence including fuse elements for preventing an unintentional release, which ignition sequence is fed with voltage by a turbine generator upon reaching a predetermined rotational speed.

In such ignition devices which serve particularly the ignition of the explosive charge of missiles, the turbine is coupled to the generator through a centrifugal clutch. Thus, the ignition system is supplied with voltage only beginning with a certain rotational speed of the spin-stabilized missle which must be ignited, that is, after a certain time of flight. A further fuse element is a slotted disk which is coupled with the axis of the generator through a gearing. Only when the slot of this disk lies between an initial charge and a firing mass can an arc-through occur. The disk carries furthermore switching contacts in order to permit a switching off of the ignition circuit or a self-decomposition of the missile when these switching contacts reach an active connection with opposite contacts, compare for example U.S. Pat. No. 3,140,651.

Aside from the fact that for arming this clockworklike ignition device, a certain spinning of the missile carrying it is required, its gear means are relatively expensive and require a space which makes their installation into relatively small spin-free explosive bodies impossible. Furthermore, such ignition devices require service in order to stay functionable during many years of storage.

An ignition device having a turbine generator became known from U.S. Pat. No. 3,401,635 in which, through a separate pressure gas producing pyrotechnic composition or explosive charge, the turbine generator is driven. During the release of the charge, locks are opened which close the flow channels of the turbine. In this manner the turbine generator device is accelerated independently of air flow very quickly to its operating speed, and on the other side is protected during the usual handling of the projectile against the effects of air flow. However, the turbine generator device can here not be used as a fuse element because the charge producing fuel gas is ignitable at any time and, therefore, a sufficient ignition voltage, independent from the presence of an air flow, can be supplied.

In addition, a relatively long structural length for storing the ignition device is required especially since the gas pressure producing charge is relatively great with respect to the initial and detonator charges. Such ignition devices can thus also not be used in explosive bodies of the type mentioned in the beginning Due to the missing spin or torsional force or sufficiently high accelerations which lie above the normal accelerations during handling, no significant forces occur in such explosive bodies which are identified as so called stray munition, which forces could be used as a release criteria for releasing the ignition device. Such explosive bodies have no own acceleration charge, but are tired with the aid of rocket warheads or are distributed fro charging containers loaded within the battlefield. As a clear application criteria there occurs therefore only a longer lasting free, but mostly oriented, fall of such explosive bodies after having been expelled from the warhead or container so that the use of turbine generators are fuse element would be ideal. Due to their small dimensions and the type of their explosive charge which is often constructed as a hollow charge, it is, however, not possible to use the known, relatively large sized ignition devices which have a rigid coaxial association of turbine, fuse element and generator.

Therefore, the basic purpose of the invention is to produce a new ignition device having an ignition sequence which has fuse elements which prevent an unintentional release, which ignition sequence is fed with voltage by a turbine generator, the mechanical structural parts of which are constructed smaller and sun pler than is known to date and in which a coaxial arrangement of turbine, fuse element and generator is lacking so that an ignition device is made possible without gearing and requires little space and is operational even after being stored for many years, which ignition device can be used for spin-free flying explosive bodies having the smallest of dimensions and which have explosive charges that are constructed for example as hollow charges or fragment charges.

Beginning with an ignition device of the type mentioned above, this purpose is attained according to the invention in such a manner that the turbine generator is supported movably as a part of the ignition sequence in relation to a fuse element and is movable explosively into its position which unlocks the ignition sequence to an ignition pellet, which pellet is fed by the generator voltage through a threshold gate member.

The turbine generator which has a pole wheel, which is constructed as a turbine, is hereby held in the fuse position in a frame by means of a deforming element against the force of a spring, in which fuse position it blocks a fuse element carrying a detonator and is held against the force of a further spring in its fuse position and a further ignition pellet is associated with the detonator which is releasable through a timing element by the generator voltage as soon as the turbine generator is in the activated position into which it can be brought by the release of an explosive charge.

The fuse element carrying the transfer charge is thus held by both a mechanically an also an explosively releasable lock.

The threahold member is advantageously a four layer diode applied to the generator voltage through a capacitor.

According to a second embodiment of the invention the ignition chain has a battery activatable by the generator voltage, which battery after being activated feeds the ignition circuit through an electronic delay unit.

According to a third embodiment of the invention, the ignition sequence has an activatable liquidammonia-battery with which is associated an explosive ignition pellet which at the same time effects the re lease of the lock of the fuse member carrying the ignition charge.

The inventive construction of the ignition device has a series of advantages. Thus it is possible to construct the turbine extremely small because the force which is required for the various operational processes of the ignition operation is produced by electrically activatable elements and the turbine does not need to operate any mechanical fuse elements, like centrifugal clutches or the like. The fuse element and turbine generator do not need to be arranged coaxially so that an optimum use of the available space is possible. Since furthermore clockworklike gearings, functioning as delay elements, are not needed. all servicing problems are overcome. The construction of the turbine as a polewheel simplifies also the ignition device especially since the space and the weight for a special generator pole wheel can be saved.

The invention will be described more in detail hereinafter in connection with several exemplary embodiments illustrated in the drawings, in which:

FIG. 1 is a partial cross-sectional top view of an ignition device according to the invention;

FIG. 2 is a top view of the ignition device according W to FIG, 1 with the rotatingturbine generator device moved out;

FIG. 3 is a cross-sectional view taken along the line llIIll of FIG. 1;

FIG. 4 is a side view of the ignition device according to FIG. 1;

FIG. 5 is a side view of the turbine generator;

FIG. 6 illustrates a circuit diagram of the ignition device according to FIG. 1; and

FIG. 7 illustrates a modified circuit diagram of the ignition device according to FIG. 1.

A housing 1 is arranged within a cylindrical explosive body, which is here not illustrated, and includes an ignition device which will yet be described. The housing 1 has a recess 2 which receives a rotating wheel-like turbine generator device G therein. A spring 3 is utilized to urge the turbine generator device G toward one position, which is illustrated more in detail in FIG. 5, namely the position illustrated in FIG. 2.

The turbine generator device G consists substantially of a multipart housing 5 which has a circular recess 6 therein, a through hole 7 the axis of which lies at a right angle to the axis of the recess 6 and an irregularly formed recess 8. The recess 8 has stator laminations 11 mounted therein with induction coils l wound therearound. The stator laminations are associated with a pole wheel 12 mounted for rotation in the circular recess 6. The pole wheel 12 has wing-like poles 14 thereon extending outwardly therefrom. The magnetic poles 14 of the pole wheel 12 rotatably supported in the cover plates 13, which poles are here not illustrated in detail, are at the same time constructed as rotating wings which extend into alignment with the through hole 7.

As is illustrated in FIG. 1, the housing has a shoulder 15 which lies against a deforming element 16 (FIG. 2) which is secured on the sidewall of an opening 18 in the housing I when the turbine generator device G is moved out of the recess 2.

Furthermore, the turbine generator device G has a pyrotechnic composition 20 associated therewith which is provided within the space of the recess 2 occupied by the spring 3. This explosive charge lies in an ignition circuit which will be described later on.

A further recess 22 is provided in the housing I and is at a right angle to a recess 18. A fuse element 23 is received in the recess 18. The fuse element is supported for a pivoting, or swinging, movement of 90 in the housing 1 by means of a bolt 24. A spring 25, which engages on one side the housing 1 and on the other side a slot on the bolt 24, urges the fuse element 23 to swing into the position illustrated in FIG. 3. The fuse element 23 is prevented from this swinging movement by the already mentioned deforming element 16 which is provided in the range of swing of the fuse element. The

fuse element 23 has an offset through bore 26 which is filled with a detonator or primer 28. A further bore 30 which is arranged at a right angle to the through bore 26 connects, in the armed position illustrated in FIG. 3, the detonator or primer to a further offset bore 31 in the housing 1 having an ignition pellet 32 arranged therein.

The fuse element 23 has furthermore a groove 34 therein which is located in an outer surface, which groove 34 is engaged by a fuse pin. The fuse pin is provided on a bolt 36 which is mounted in the housing I and which, as soon as the explosive body has left it charging container or the like, moves under the influ- V V ence of a spring, which is here not illustrated. into the position illustrated in FIG. 4. In this position. the fuse pin 35 is out of engagement with the groove 34 of the fuse element 32.

A tube 39 is furthermore connected to the housing 1, which tube 39 includes a draw-in wire 40. A pull switch 42 (FIG. 6 only) is closed by the draw-in wire 40, as soon as the explosive body has left its charging container. The pull switch 42 lies in the ignition circuit which will be described below.

Finally a further switch 43 is secured on a plate 44 on which is mounted a part of the ignition electronics which will be described below, and which is operated by a rod 45. A further plate 46 which is arranged above the recess 2 has a portion of the ignition electronics mounted thereon which as stated above will be described below.

The already mentioned ignition electronics will now be described in detail in connection with FIG. 6. The turbine generator device G which supplies an ac. voltage charges through a resistor R, and a diode D, to a capacitor C,. whereby the charging time of the capacitor C, is governed by the magnitude of the resistor R, which is composed of the generator inner resistance and the outer resistance. The magnitude of the generator voltage is determined by the rotational speed of the pole wheel 12 and by further design characteristics of the generator A voltage-dependent switch, for example in the form of a four layer diode D or a MOS switch, is connected to the capacitor C and diode D,, which switch is connected in series with the explosive charge 20.

A further diode D is connected through the normally closed switch 43 to the capacitor C,, through which diode D, an ignition capacitor C is charged to approximately the same voltage as the capacitor C,. An electronic timing element 47 is fed through the diode D which, if the pull switch 42 is closed, causes the ignition pellet 32 to react. If during this instant the fuse element is in the armed position, illustrated in FIG. 3, the detonator or firing material 28 is ignited through the ignition pellet, which detonator material releases the here not illustrated explosive charge of the explosive body.

The above-described device operates as follows:

As soon as the explosive body has been ejected from the rocket warhead or from a charging container, the bolt 36 and thus the fuse pin 35 moves into the position illustrated in FIG. 4 and thereby disengages from the fuse element 23. At the same time the turbine generator device G has been moved by the spring 3 away from the position illustrated in FIG. 1 to the position illustrated in FIG. 2 so that it can be rotated by the air surrounding it. The capacitor C, is charged by the voltage now produced by the turbine generator device G. The

capacitor C is brought to the same voltage through the closed switch 43 and the diode D If now the voltage of the capacitor C exceeds the ignition voltage of the voltage-dependent switch diode D -then same releases the explosive charge 20. The gas pressure which builds up thereby deforms, through the housing 5 of the turbine generator device, the deforming element 16 so that same releases the fuse element 23. Said fuse element is swung 90 degrees under the influence of the spring 25 and thereby into the armed position illustrated in FIG. 3- the fuse pin 35 was disengaged already at the beginning thus, the detonator or firing material 28 can be fired by the ignition pellet 32. During a switching movement of the fuse element into its armed position, the switch 43 is opened by a movement of the rod 45 so that the circuit consisting of diode D and ignition capacitor C is separated from the turbine generator device G. Thus, the ignition capacitor C is charged only to the voltage which is predetermined by the voltage-dependent switch D If now the timing element 47 releases an ignition impulse, then same causes, as already mentioned, the igni tion pellet 32 to react and releases through this the detonator or firing material 28.

If the switch 42 is not closed, however, the detonator or firing material 28 cannot be ignited.

In the exemplary embodiment illustrated in FIG. 7, in which the same reference numerals were used for the identical structural parts as illustrated in FIG. 6, through the aid of the explosive charge 20, not only is the fuse element 23 released to its armed position, but simultaneously also an activatable battery 48 is actuated. The battery 48 is, for example, a liquid-ammoniabattery which consists of an electrochemical system 49 and a gas container 50 containing ammonia. After the activation of the battery 48, same supplies the ignition circuit consisting of the already mentioned timing element 47 and the ignition pellet 32.

Of course other arrangements of the electrical ignition circuit are possible, in particular a filter can be connected in a conventional manner between the generator and diode D, so that by choosing the frequency zone of the filter, the explosive body is supplied with voltage only after reaching a certain fall velocitycorresponding to a certain rotational speed of the turbine generator.

As is shown by the aforedescribed ignition devices, the turbine generator device can be stored in a different location than the fuse element, whereby the releasing criteria can be transmitted in the form of a voltage surge or impulse through electrical lines to the location ofthe fuse element so that an extremely compact structure and the use of mechanically simple connecting devices is possible.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an ignition device including a turbine generator and having an ignition sequence including a fuse element prevented from an unintentional release, which ignition sequence is fed with voltage by said turbine generator upon reaching a predetermined rotational speed, the improvement comprised in that the turbine generator is supported movably, as a part of the ignition sequence, in relation to said fuse element and is movable into an unlocking position which unlocks the ignition sequence to a pyrotechnic composition and including a threshold gate member, said pyrotechnic composition being fed by the generator voltage through said threshold gate member.

2. Ignition device according to claim I, in which the turbine generator has a housing and a pole whecl con structed as a windmill and disposed in said housing, said turbine generator being held in a fuse locking position by means of a deforming element and against the force of a spring, in which fuse lockingposition of said turbine generator, said deforming element blocks said fuse element, holding said fuse element against the force of a further spring, said fuse element carrying a primer, a further ignition pellet associated with the primer, and a timing element, said pellet being releaseable through said timing element by the generator voltage as soon as the turbine generator is in said unlocking position.

3. Ignition device according to claim I, in which said fuse element has an armed position to which it is movable in response to turbine generator movement, and including an ignition circuit incorporating a switch operable by said fuse element as soon as said fuse element is released to said armed position.

4. Ignition device according to claim I, in which the threshold member is a four-layer diode and including a capacitor chargeable by the generator voltage and coupled to said threshold member.

5. Ignition device according to claim 1, including an ignition circuit and an electronic delay unit, in which the ignition sequence has a battery which can be acti vated through the generator voltage and which after being activated feeds the ignition circuit through the electronic delay unit.

6. Ignition device according to claim 5, in which said fuse element carries a primer and the activatable battery is a liquid-ammonia-battery, said pryotechnic composition being an ignition pellet energizable for activating said battery and simultaneously for releasing the primer to an armed position ready to be fired by said ignition circuit.

7. An ignition device according to claim 2, in which said fuse element has an armed position to which it is movable by said further spring and including an ignition circuit incorporating a switch operable by said fuse element as soon as said fuse element is released to said armed position.

8. An ignition device according to claim 3 in which said threshold member is a four-layer diode and including a capacitor chargeable by the generator voltage and coupled to the threshold member for causing the latter to activate said pyrotechnic composition.

* =l l =l=

Claims

2. Ignition device according to claim 1, in which the turbine generator has a housing and a pole wheel constructed as a windmill and disposed in said housing, said turbine generator being held in a fuse locking position by means of a deforming element and against the force of a spring, in which fuse locking position of said turbine generator, said deforming element blocks said fuse element, holding said fuse element against the force of a further spring, said fuse element carrying a primer, a further ignition pellet associated with the primer, and a timing element, said pellet being releaseable through said timing element by the generator voltage as soon as the turbine generator is in said unlocking position.

3. Ignition device according to claim 1, in which said fuse element has an armed position to which it is movable in response to turbine generator movement, and including an ignition circuit incorporating a switch operable by said fuse element as soon as said fuse element is released to said armed position.

4. Ignition device according to claim 1, in which the threshold member is a four-layer diode and including a capacitor chargeable by the generator voltage and coupled to said threshold member.

5. Ignition device accOrding to claim 1, including an ignition circuit and an electronic delay unit, in which the ignition sequence has a battery which can be activated through the generator voltage and which after being activated feeds the ignition circuit through the electronic delay unit.