EP3771881A1 - Pyrotechnic initiator for initiating an ignition tube and method for initiating an ignition tube - Google Patents

Abstract

The invention relates to a pyrotechnic initiator and a corresponding method for initiating an ignition tube by means of an electrical trigger, comprising a sleeve open on one side with an ignition pill located therein made of a glow wire and a pyrotechnic set surrounding the glow wire or several pyrotechnic sets for generating a shock pulse, with the sleeve, which is open on one side, the ignition hose can be coupled and an explosive present in the ignition hose can be initiated by the shock pulse.

Description

The invention relates to a pyrotechnic initiator for initiating an ignition tube according to claim 1 and a method for initiating an ignition tube according to claim 10.

Ignition hoses are mainly used for pressure-based triggering of long-range firing devices or defusing devices, for the pyrotechnical generation of light flashes in film and television production facilities and / or for the orderly forwarding of an ignition pulse from one or more triggering devices to the explosive charges that are ultimately to be detonated (e.g. in a quarry for the extraction of Gravel stones for road construction). An ignition hose usually consists of a mixture of explosives, for example a mixture of octogen and aluminum.

The transmission of the ignition pulse in an ignition hose is based on a so-called shock hose effect. An explosive is very finely distributed in a hose. Under these circumstances, the explosive detonates in a directional manner with the creation of a flash of light within a surrounding plastic tube. An explosion triggered at one end of the ignition tube can be conducted over any distance using this mechanism. In doing so, the plastic hose, as a pure means of transport for the transmission of the ignition pulse or light flash, is generally not destroyed. Such ignition tubes are - depending on the type of triggering and the specific intended use - optionally closed at one end and firmly connected to a detonator at the other end.

The causing of an initial ignition of the explosive in the ignition hose is referred to below as initiation. The means by which this initiation is effected is hereinafter referred to as the initiator.

Ignition hoses are mainly used in blasting technology to detonate a detonator (usually with a primary explosive, e.g. lead or Silver azide) attached to the end. The ignition hose offers the advantage that an ignition pulse can be transmitted in a non-electrical way and that this transmission is resistant to external influences (in particular to electrostatics and radio waves). This reduces unwanted pre-ignition.

Various ignition variants are known for ignition hoses for initiating the ignition pulse.

In a first ignition variant, a detonator - usually filled with a primary explosive - is used, which generates a detonative shock pulse. The detonator capsule is a closed metal capsule that is mainly filled with a primary and secondary charge made up of various explosives. One capsule contains approximately 1,100 mg of explosive. The disadvantage of this variant is that a detonator used for initiation explodes during ignition due to the construction-related structure required, with energetic splinters occurring which are lethal in the close range.

Alternatively, with a second ignition variant, a hose release with a high-energy piezo spark is carried out. However, the piezo spark requires high voltages and amounts of energy. The high voltage can also have a lethal effect if, for example, a defect in the shielding leads to discharges on the human body.

In a third ignition variant, percussion caps are used that contain small amounts of primary explosives such as lead trinitroresocinate and tetrazene. These are ignited mechanically. Although these funds are freely available and can also be used by inexperienced users, they do not allow the ignition tube to be initiated from any distance. The user with the triggering device must always be at the end of the ignition tube and thus relatively close to the explosion site, unless the ignition tube is made particularly long, which then, however, causes higher costs due to the use of material.

There is thus the object of specifying a device and a method with which an initiation of an ignition tube from practically any Distance, wired and in particular also wirelessly, for example via an air interface (radio), can be carried out. The initiation should in any case be executable for the personnel involved without the risk of injury and also initiate the ignition hose safely so that misfires are practically excluded.

The object is achieved on the device side with a pyrotechnic initiator for initiating an ignition tube with the features of claim 1 and on the method side with a method for initiating an ignition tube with the features of claim 10. The subclaims each contain expedient and / or advantageous embodiments and configurations.

According to the invention, a pyrotechnic initiator is provided on the device side for initiating an ignition tube by means of an electrical trigger. This comprises a sleeve open on one side with an ignition pill located therein. The ignition pill consists of a glow wire and a pyrotechnic set or several pyrotechnic sets surrounding the glow wire for generating a detonating shock pulse. The ignition hose can be coupled to the sleeve open on one side and an explosive present in the ignition hose can be initiated by the shock pulse.

The basic idea of the pyrotechnic initiator according to the invention is thus to make electrical triggering possible via the combination of a glow wire and a pyrotechnic set or several pyrotechnic sets. Usually, pyrotechnic set triggers are designed to trigger pyrotechnic effects (such as Bengal lights or fuses based on black powder). Similar to the head of a match, they produce a burning flame and hot sparks for a short time. Conventionally, sentence triggers belong to the type of igniter, they do not generate a detonative shock pulse.

According to the invention, however, the pyrotechnic active ingredient is not formed from a typical slow-burning igniter material as is usually the case with conventional igniter pills; it therefore does not burn off slowly in the actual sense. With such a conventional ignition pill, it is not even possible to initiate an ignition tube.

Instead, the invention provides for the pyrotechnic charge to explode quickly and thereby initiate the explosive in the ignition tube. The sleeve, which is open on one side, aligns the effect of the explosion with the ignition hose. In contrast to the otherwise used piezoelectric ignition mechanisms, according to the invention no dangerous electrical voltages are used. The shock pulse, however, causes the ignition hose to be initiated effectively and reliably.

It is therefore an essential aspect of the basic idea according to the invention to use the principle of the sentence trigger to initiate the ignition hose and to design the initiator accordingly. In contrast to the known detonator capsule, however, the initiator according to the invention is not an explosive detonator, since the impulse emanating from the object - as with a percussion cap with a very small amount of explosive charge - is not sufficient to initiate a sensitive explosive test charge. However, since the mixtures used in ignition hoses contain a highly explosive substance and pyrophoric aluminum, ignition hoses are more receptive and significantly easier to initiate than a commercially available explosive.

In one embodiment, a splinter protection is provided for surrounding the sleeve for the sleeve which is open on one side, the splinter protection catching a lateral tearing of the sleeve during the generation of the shock pulse and preventing splinters of the sleeve from being released into the environment.

This eliminates the risk of splinters being thrown around and achieves a high level of safety for the user, even in the preparatory activities that are otherwise critical from the point of view of occupational safety.

In one embodiment, the splinter protection is designed as a flexible hose surrounding the sleeve, in particular a compressed air hose with thread inserts. Such an embodiment is mass-saving and reliably prevents the release of splinters.

Alternatively, the splinter guard can be designed as a rigid cylinder surrounding the sleeve, in particular as a metal or plastic cylinder. In one embodiment, the sleeve, which is open on one side, has a sleeve bottom in the form of a plug that can be inserted into the sleeve, the plug having feed-through openings for electrical leads for the glow wire. The at least one pyrotechnic set can thereby be plugged together by joining the plug with the sleeve.

In a further embodiment, an adapter is provided for centered insertion of the ignition tube into the sleeve, the end of the ignition tube being positionable immediately in front of the ignition pill. The adapter ensures an optimal coordination between the diameter of the ignition hose and the diameter of the sleeve, an optimal positioning of the ignition hose on the sleeve and an optimal transfer of the explosion effect to the end of the ignition hose.

It is advantageous if the adapter, the ignition hose and the sleeve form an arrangement that can be fixedly fixed and / or sealed with one another using a pliers tool.

The pyrotechnic charge is designed to explode quickly. Above all, this means that the pyrotechnic charge of the ignition pill is designed to generate a considerable explosion pressure of more than 10 bar in conjunction with a shower of sparks directed at the end of the ignition tube.

In terms of the method, the invention provides for initiating the ignition tube that a shock pulse is applied to an open end of the ignition tube via an ignition pill consisting of a glow wire and a pyrotechnic charge or several pyrotechnic charges, and an explosive present in the ignition hose is initiated by the effect of the shock pulse, and a detonation occurs.

The shock pulse expediently acts as a directed explosion pulse on the end of the ignition tube, with the end of the ignition tube and the ignition pill being located within a surrounding sleeve that determines the direction of explosion for this purpose.

The explosion pressure of the shock pulse is expediently greater than 10 bar during the process.

The pyrotechnic initiator according to the invention and the method according to the invention are to be explained below on the basis of exemplary embodiments. The serve for clarification Figures 1 and 2 . The same reference symbols are used for parts that are the same and have the same function.

Fig. 1

den pyrotechnischen Initiator in seinem prinzipiellen Aufbau,

Fig. 2

eine beispielhafte Gestaltung des pyrotechnischen Initiators.

It shows:

Fig. 1

the pyrotechnic initiator in its basic structure,

Fig. 2

an exemplary design of the pyrotechnic initiator.

Fig. 1 shows an exemplary structure of the pyrotechnic initiator. The figure shows an ignition hose 1 which is coupled to a pyrotechnic initiator. The pyrotechnic initiator contains a sleeve 2. This is open on one side in the direction of the ignition tube. The sleeve can for example consist of a metallic material, but also of plastic. The sleeve 2 contains an igniter pill 3 inside. The igniter pill 3 consists of a glow wire 5 arranged between two electrical poles 4 and a pyrotechnic set or several pyrotechnic sets 6 that surrounds the electrical poles and the glow wire.

The pyrotechnic charge or the multiple pyrotechnic charges can be made to explode via the glow wire. Electrical supply lines 7 are provided for the electrical application of the glow wire. When the pyrotechnic charge explodes, the explosion acts primarily in the direction of the ignition tube and initiates an explosive 8 within the ignition tube 1, the detonation of which then continues through the ignition tube to the respective target location, provided the tube is used for explosive purposes.

The explosion of the pyrotechnic charge or the pyrotechnic charge 6 also causes the sleeve 2 to burst as a rule. The fragments and splinters produced during the bursting are caused by the sleeve surrounding splinter protection 9 and prevented from releasing into the environment. A flexible design of the splinter protection is advantageous here, in particular in the form of a hose section which is reinforced inside with a thread mesh.

A rigid design of the splinter protection in the form of a non-metallic or metallic casing, for example in the form of a plastic or steel cylinder, is of course also possible.

In the schematic structure shown here, the base of the sleeve 2 consists of a plug 10 which can be inserted into the sleeve and through which the electrical supply lines 7 are passed via feed-through openings 10a. The entire arrangement of plug 10 and igniter pill 3 can be inserted into the sleeve as a whole.

For the precise and centered positioning of the ignition hose 1 in the sleeve 2, an adapter 11 is also provided. This is attached to the ignition tube 1 and then inserted into the sleeve 2 together with the ignition tube, the end of the ignition tube being placed directly on the ignition pill 3 and thus coming into contact with the pyrotechnic charge. The adapter can be both rigid and flexible and can be made of different materials, for example plastic or metal. In the case of a flexible design of the adapter, it is designed as a hose section. Finally, this entire unit, i.e. the sleeve 2 with the adapter 11 is crimped with pliers and is ready for use. The igniter pill 6 with the plug 10 and the metal sleeve 2 is usually also crimped.

The splinter protection 9 is then pushed onto the entire arrangement of adapter with ignition hose, sleeve and plug. If necessary, fixation is carried out e.g. by means of a sufficiently strong adhesive tape, in particular a fabric adhesive tape.

Fig. 2 shows an example of use of the pyrotechnic initiator. The initiator consists here of the igniter pill 3 and the sleeve 2 surrounding this igniter pill. In the sleeve 2 surrounding the igniter pill is the adapter 11 with the Ignition hose 1 inserted. The ignition tube 1 protrudes a certain distance into the area of the ignition pill 3 via a projection 13 and is thereby centered in its position. A fluting 12 on the sleeve 2 prevents the ignition hose from slipping.

The splinter protection 9 in the form of a flexible hose section is pushed directly onto the sleeve 2 and the adapter 11. There is thus a flexible splinter protection. The electrical supply lines 7 open into the igniter 6.

The initiation of the ignition hose with the device described here is as follows:
As described, the ignition pill is located in the sleeve, which is open at the front. This contains two poles, between which the filament is attached. Explosive mixtures, for example of zirconium and potassium perchlorate, are arranged as a pyrotechnic charge around the glow wire. If necessary, the filament is initially surrounded by a first, heat-sensitive pyrotechnic charge, which reacts more quickly to heat, before the actual active mass follows as a second pyrotechnic charge. The net explosive mass for the entire initiator is up to 100 mg.

The supply lines to the poles are led backwards through a stopper or plug with two holes out of the sleeve. The supply lines can be extended almost as required and can be connected to radio ignition devices in particular. This enables triggering from a greater and therefore safer distance.

The adapter is inserted into the open end of the sleeve, as described, into which the open ignition tube is in turn inserted into the sleeve up to immediately in front of the ignition pill. Then the hose is crimped tight with pliers. The adapter can be designed flexibly as a hose adapter.

If a defined current is applied to the poles through the cable, the wire glows and causes the pyrotechnic charge to explode. A pressure pulse with a strength of more than 10 bar and a shower of sparks are created. By their effect, the explosive in the ignition tube is finally triggered and the ignition tube is stimulated to pass on the detonating explosive pulse. The explosive pulse can now be passed on through the ignition hose to the actual location of the intended effect, that is to say in particular to the intended explosive device if an explosive device is used.

Since the ignition hose in this case is inserted centered in the metal sleeve by means of the adapter and fixed and sealed almost watertight (for example with crimping pliers), the pressure build-up in the sleeve is considerably increased and can act in a concentrated manner on the end of the ignition hose.

The pressure generated in the sleeve and the sparks can initially only escape into the open ignition tube; there it triggers the hose or the explosive buildup located there. This arrangement promotes reliable initiation, since otherwise the hose will not be initiated correctly.

The sleeve of the initiator may tear open laterally as a result of the rapid explosion, which can occasionally result in splinters. Due to the special construction of the igniter and the splinter protection pushed over the case, however, unlike a normal detonator, no high-energy case fragments are released, but rather intercepted. The splinter protection pulled over the sleeve usually consists of a conventional compressed air hose with thread inserts. Rigid steel or plastic cylinders can also be used as splinter protection, but these are comparatively heavy.

Due to its specific structure, the present record trigger can initiate an ignition hose on the one hand. On the other hand, it only requires an extremely small security area. The initiator present here could even be held in the hand in a completely harmless way due to the structure and the splinter protection when triggered. Lethal or even injurious splinters are not generated when used as intended.

According to the provisions of the law on explosives, conventional detonators may only be handled by trained specialists. These require official approval. This also applies to transport, for example for drivers of trucks. Moving detonators, especially in the EU, from one country to another also requires a corresponding permit from all countries.

On the other hand, the present initiator is legally possible and permissible for persons aged 18 and over without specialist knowledge due to the present design. Shipping can therefore take place with a normal parcel service and even without a special shipment permit. In contrast to conventional detonators, which can also be used to initiate an ignition hose, this allows cost-effective transport.

In comparison to piezo tripping elements, which can be used multiple times but are comparatively expensive, the initiator described here can only be used once. On the other hand, it is much cheaper to manufacture and also enables simple and safe triggering from a distance with completely harmless operating voltages. In principle, the initiator described here can be combined with and connected to all voltage-supplying power sources. These can be controlled in any way, in particular wirelessly, so that there is the possibility of simultaneous remote triggering of several ignition hoses, which is otherwise only possible with ignition variant 1 and not with variants 2 and 3.

The initiator and the process carried out with it were explained by way of example. Further configurations are possible in the context of professional action. Further embodiments also emerge from the subclaims.

List of reference symbols

1

Ignition hose

2

Sleeve

3

Ignition pill

4th

Electric pole

5

filament

6th

Pyrotechnic kit

7th

Supply lines

8th

Explosive

9

Splinterguard

10

Plug

10a

Feed-through opening

11

adapter

12

Corrugation

13

Got over

Claims (12)

Pyrotechnic initiator for initiating an ignition hose (1) by means of an electrical trigger, comprising
a sleeve (2) open on one side with an ignition pill (3) made of a glow wire (5) and at least one pyrotechnic charge (6) surrounding the glow wire for generating a shock pulse that initiates the end of the ignition tube,
wherein the ignition hose (1) can be coupled to the sleeve (2) which is open on one side and an explosive (8) present in the ignition hose can be initiated by the shock pulse. Pyrotechnic initiator according to claim 1,
characterized in that
For the sleeve (2) open on one side, a splinter protection (9) is provided for surrounding the sleeve, with the splinter protection (9) being able to catch the sleeve (2) tearing open during the generation of the shock pulse and preventing splinters from being released into the environment is. Pyrotechnic initiator according to claim 2,
characterized in that
the splinter protection (9) is designed as a flexible hose surrounding the sleeve (2), in particular a compressed air hose with thread inserts. Pyrotechnic initiator according to claim 2,
characterized in that
the splinter protection (9) is designed as a rigid cylinder surrounding the sleeve (2), in particular a metal or plastic cylinder. Pyrotechnic initiator according to one of the preceding claims,
characterized in that
the sleeve (2) open on one side has a sleeve base in the form of a plug (10) that can be inserted into the sleeve, the plug (10) having feed-through openings (10a) for electrical leads (7) for the glow wire (5). Pyrotechnic initiator according to one of the preceding claims,
characterized in that
an adapter (11) is provided for centered insertion of the ignition tube (1) into the sleeve (2), the end of the ignition tube being positionable directly in contact with the ignition pill (3). Pyrotechnic initiator according to claim 6,
characterized in that
the adapter (11), the ignition hose (1) and the sleeve (2) form an arrangement that can be fixed and / or sealed to one another using a pliers tool. Pyrotechnic initiator according to one of the preceding claims,
characterized in that
the pyrotechnic set (6) of the igniter pill (3) is designed to generate an explosion pressure of more than 10 bar in connection with a shower of sparks directed at the end of the ignition tube. Pyrotechnic initiator according to one of the preceding claims,
characterized in that
the pyrotechnic initiator has a net explosive mass of a maximum of 100 mg. Procedure for initiating an ignition hose,
characterized in that
An ignition pill (3) made of a glow wire (5) and a pyrotechnic charge (6) causes a shock pulse to act on an open end of the ignition tube (1) and the effect of the shock pulse initiates an explosive in the ignition tube. Method according to claim 10,
characterized in that
the shock pulse acts as a directed pulse on the end of the ignition tube (1), the end of the ignition tube (1) and the ignition pill (3) being located within a surrounding sleeve (2) which determines the direction of explosion. Method according to one of Claims 10 or 11,
characterized in that
the explosion pressure of the shock pulse is greater than 10 bar.

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