WO2003014652A1

WO2003014652A1 - Detonator with improved spacial location of its effects and efficient setting of initiation power

Info

Publication number: WO2003014652A1
Application number: PCT/CZ2002/000047
Authority: WO
Inventors: Pavel Valenta; Jan Jakubko; Zdenek Urban; Moris Ross Bannerman; Goran Jidestig
Original assignee: AUSTIN DETONATOR
Current assignee: AUSTIN DETONATOR
Priority date: 2001-08-06
Filing date: 2002-08-05
Publication date: 2003-02-20
Anticipated expiration: 2004-02-06
Also published as: EP1488187A1; CZ20012859A3; CZ292545B6

Abstract

The invention involves detonators with improved settings of spatial and initial power and brisance effects, where the detonator contains delayed-action pyrotechnic, primary and secondary charges arranged in a line and characterised by the principle that both primary (4) and secondary (3) explosive sub-charges are placed in the detonator jacket (1) in the first internal casing (2), which is shaped, at least along its part containing the secondary explosive charge (3), a prismatic shape.

Description

DETONATOR WITH IMPROVED SPATIAL OCATION OF ITS EFFECTS AND EFFICIENT SETTING OF INITIATION POWER

Technical Field

The invention concerns industrial detonators, both electric and nonelectric ones. This involves electrical detonators, which in their electrical design after the initiation by electric current or in their non-electric design after being initiated by a pulse from detonating tubes, burning fuses or detonating cords, generate by explosive conversion of their charges into detonating and impulse wave that consequently, along with fragments of explosive charge coat of the relevant industrial detonator, influence initiatively to other explosive objects forming detonating networks.

Background Art

In the sphere of explosives and relevant segment of explosive systems (trains) based on applications of low-energy detonating tubes in particular, the requirements for improved detonator properties and, first of all, those for an exact quantification of primary power and exact space location of its effects, gradually increase. As with normal detonators the above given exactly specified space-located primary effects cannot be achieved, normal detonators are unsuitable for such use. In the priming systems equipped with low-energy detonating tubes, the detonator must be able to transfer the exactly space specified and correctly dimensioned initiation impulse so as not to damage other connected elements nearby the detonator by an oversized initiation power. The currently known and used detonator designs, where the explosive charge is directly placed to a not particularly modified bottom part of metal cylinder cup (usually of 6 mm internal diameter), do not make possible to achieve, in a reliable and easy way, the specified initiation space effects and transfer the detonation to other connected elements of priming systems and, at the same time, to minimize the negative effects of high initiation power nearby the detonator damaging the priming system elements nearby the detonator with consequent failures in the priming system. Such non-electric igniting detonator is, for instance, described in CZ Patent No. 286402, where the secondary explosive charge is placed directly in the metal cap. Similarly, the delay-action detonator in the design according to US Patent No. 5182417 has its secondary explosive charge placed under its primary one, directly in the metal cup - here concretely in an aluminium casing. A similar arrangement is also used in detonator types according to RU Patents No. 2066829, No. 2089828, No. 2120101 , No. 2148239, No. 2148240, No. 2149341 and No. 2156945, or according to EP Patent Application No. 0679858. Certain specific directing of initiation pulses is achieved in the detonator type according to US Pat. No. 6062141 so that the cup, in its section-through arrangement, is designed in a combined surface consisting of grooves and crests but with its explosive charge placed again directly in the cup so that, beside an improved control of space-orientated effects, no progress in the control of detonator initiation power is achieved here.

Disclosure of Invention

According to the invention as herein submitted, higher accuracies in defining both power and direction aspects of detonator initiation power is achieved by the use of the detonator with improved setting of initiation power and brisance, where the detonator contains, placed in a line, a delay-action pyrotechnic, primary and secondary explosive charges, and where the principle consists in that both primary and secondary explosive charges are placed in the detonator cup in the first internal casing, which is shaped, at least along its part containing the secondary explosive charge, a prismatic shape. To further advantage, the cavity in the first internal casing may gradually widen towards the delay-action pyrotechnic. The delay-action pyrotechnic may be then, to further advantage, placed in a second internal casing. This second internal casing may be advantageously shaped into a ring tube. The first internal casing may have its cavity shaped to circular, star, or cross-like sections-through. First internal casing perimeter walls may have advantageously the same thickness as the casing bottom thickness. The first internal casing may be manufacture advantageously from non-metal materials. The first internals casing contains advantageously the explosive charge, consisting of primary and secondary explosives; the charge is loosely poured in this casing. Alternately, the first internal casing may contain the explosive charge, consisting of primary and secondary explosives, compacted to densities from 0.5 to 3.0 g/cm³. This way the very detonator, providing reliable detonation and impact power for initiation acting to other explosive subjects forming blast distribution network and, at the same time, enabling an easy setting of initiation power so as not to damage other network neighbouring elements, can be accomplished.

Brief Description of Drawings

Below, the submitted invention is explained in detail in a typical design that is illustrated at the drawing enclosed herewith and where, on Fig. 1 , the detonator cup is shown in vertical/horizontal sections along with internal casings filled with the delayed-action pyrotechnic and explosive charge and furthermore in Figs. 2, 3 and 4 in cross sections, options of the internal casing containing the explosive charge. Description of the Preferred Embodiment

The detonator prepared according to this invention is formed in the jacket

1, where in its bottom part, the first internal casing 2, containing the explosive (secondary) charge 3 is loaded, and furthermore, where in its funnelling top part the jacket contains the primary explosive charge 4 is located. Above this assembly of first internal casing 2, the second internal casing 5 is loaded; this casing is filled with delaying pyrotechnic 6. In one of typical design options, the first internal casing 2 is shaped as a cylinder, the bottom of which is thinner than the perimeter walls. In the second typical design option, the perimeter walls of the first internal casing 2 are shaped to form a star-like section-through cavity inside. In the third typical design option, the first internal casing 2 is shaped to form a cross-like section-through cavity inside. At the same time, both second and third typical designs have their thinnest spots at the perimeter walls of the first internal casing 2, in such thicknesses as that of its bottom. As regards materials used in the first internal casing 2, plastics are used in this case. The second internal casing 5 is made of metal. As for the explosive charges they consist here of secondary explosive 3, represented by pentaerythrite tetranitrate and primary explosive 4, represented by plumbous azide and, in the above typical designs, the explosive charge is pressed in the first internal casing 2. The second internal casing 5, into which the delayed-action pyrotechnic 6 is bulk placed, has in all the typical designs a cylindrical section-through. All casing designs described here have been tested for the ability of easy tuning of initiation power so that, after determination and first testing of the internal casing shapes and thicknesses, and in the use of the detonator according to the invention, no damaging of other elements of initiation networks happens.

Claims

C L A I M S

1. A detonator with improved settings of spatial and initiation power and brisance effects, where the detonator contains delayed-action pyrotechnic, primary and secondary charges arranged in a line and characterized in that both primary (4) and secondary (3) explosive sub-charges are placed in the detonator jacket (1) in the first internal casing (2), which is shaped, at least along its part containing the secondary explosive charge (3), a prismatic shape.

2. The detonator according to Claim 1 , characterized in that the cavity in the first internal casing (2) is widened in the place of primary (4) explosive charge in the direction to the delayed-action pyrotechnic (6).

3. The detonator according to Claims 1 and 2, characterized in that the delayed-action pyrotechnic (6) is placed in the second internal casing(5).

4. The detonator according to Claims 1 to 3, characterized in that the second internal casing (5) has the disposition of a circular tube.

5. The detonator according to Claims 1 to 4, characterized in that the first internal casing (2) contains a cavity inside and that cavity's section- through is circular, star- or cross-like.

6. The detonator according to Claims 1 to 5, characterized in that the first internal (2) perimeter walls have at least the same thickness as that one of the bottom of this first internal casing (2).

7. The detonator according to Claims 1 to 6, characterized in that the first internal casing (2) is advantageously manufactured of non-metal material.

8. The detonator according to Claim 1 to 7, characterized in that the first internal casing (2) contains an explosive charge consisting of primary (4) and secondary (3) explosive sub-charges, and this charge is placed in this casing (2) in bulk.

9. The detonator according to Claims 1 to 7, characterized in that the first internal casing (2) contains an explosive charge consisting of primary (4) and secondary (3) explosive sub-charges, and this charge is compacted in this casing to densities varying from 0.5 to 3.0 g/cm³.