FI57741C - ANORDINATION FOER INITIERING AV SPRAENGLADDNINGAR - Google Patents

Description

Γβΐ «« ANNOUNCEMENT ^ ΠΠΑΛ

Ma lbj (") utläggningsskrift 5 7 7 4 1 C Patent granted 10 10 1930

Patent Moddelat (51) ^ W3 0 06 0 5/06, F 42 D 1/04 FINLAND —FINLAND (21) PmnttIhukMnui - Ht. «» N »ftknlni 31T9 / T2 (22) HtkamlipUvt - AnaMcnlnpd * lU. 11.72 (FI) (23) Alkupllvi — GlMghvtadag lU.ll.72 (41) Tullut JulklMksI - Latches offantllf 02.06.73

Patent · And rigged »(44) NlfaMkalpunon | a moonLjulkalaun date. -

Patent · och registrentyrelMn 'AnaBtam uttafd oeh utUkrHtm publlnrad 30.06.80 (32) (33) (31) Pyydetty atuolkau * —e «j» rt prkxiuc 01.12.71 Sweden-Sweden (SE) 15380/71 (71) Nitro Nobel Aktiebolag, 710 30 Gyttorp, Sweden-Bverige (SE) (72) Hans Krister Lundborg, Gyttorp, Sweden-Sweden (SE) (74) Oy Jalo Ant-Wuorinen Ab (54) Device for igniting explosive charges - Anordning för initiering av sprängladdningar This invention applies to a device for igniting explosive charges using a low-energy ignition wire.

By low-energy ignition wire is meant herein detonating wires which have such a small explosive effect that they cannot, without an explosive or igniting charge, transfer an explosion from an ignition wire to another igniter wire or explosive of the type normally used for detonation. One useful type of low energy ignition wire is disclosed in Swedish Patent 333,321.

The device according to the invention is also useful in other embodiments of low-energy ignition wires.

For example, to ignite an explosive charge placed in a borehole, a low-energy ignition wire is connected to an explosive capsule, the explosive or ignition charge of which is ignited by a gas shock wave obtained from the ignition wire. The explosive charge of the blast capsule in turn ignites the explosive charge. The gas shock wave is generated in the ignition wire by means of a suitably adapted shock wave, spark discharge or the like.

According to one known and used method, several low-energy ignition wires are ignited simultaneously in a single series of explosions. The explosive ignition wire is usually ignited with an explosive capsule.

Ignition with an explosive ignition wire has several disadvantages due to the high specific explosive effect, which can cause damage to the environment or breakage of connected, not yet ignited low-energy ignition wires, which in turn causes a series of explosions to fail. Another drawback is the noise generated by the explosive ignition wire, which in many cases prevents its use in densely populated areas.

The object of the invention is to substantially reduce and in certain cases completely eliminate these drawbacks. This is achieved in that the device consists of one or more connectors of non-explosive material, each individual connector being provided with a hole for a low-energy ignition wire and an ignition pulse amplifier, e.g. an initial detonation capsule, and one or more channels for one or more igniters. of which said double-folded portion of said ignition wire between its ends is inserted into a duct, which, upon ignition of the initial detonation capsule, receives and transmits an ignition pulse towards both ends of the detonation wire, and than with the initial detonation capsule located above, in which case, in the same way, a series of boreholes detonation of cooling charges.

The interconnection of a plurality of such igniters into an ignition system according to the invention, all igniters comprising an explosion-proof capsule, a low-energy ignition wire of a certain length and a coupling piece 1 of the connecting piece, The displacement of a gas shock wave occurs without a decrease in its displacement rate, even if the displacement of the gas shock wave is intermittent.

It has been shown that the 3,57741 ignition wires according to Swedish patent 333,321 are sensitive to high humidity, fog, water (including a single very small droplet) and foreign particles in the gas duct. In order to ensure the operation of lighters and interconnected ignition systems, it or the gas ducts along which the gas shock wave must travel must be protected from the inside. The protection is made in such a way that the combination of several igniters, which are closed in themselves, results in a cohesive ignition wire system, the inside of which cannot be exposed to water or dirt during the connection work.

Each individual lighter, i.e. the ignition action required for each charge or borehole comprises an ignition wire and a fitting with an explosive capsule, thus forming a unit sealed against moisture, which may have a variable ignition wire length and delay interval. The interconnection of igniters into a single ignition system is accomplished by means of connectors (which are connectors with an ignitable explosive capsule or an embedded explosive charge) that can be connected to another low-energy ignition wire at any point along its length. The coupling piece mechanically connects the igniters and moves by shock wave from the igniting explosive capsule or explosive charge from the second ignition wire of the gas shock wave to the other in two opposite directions, on the one hand in one direction direction, etc. The coupling piece also provides protection against sharp fragments coming from the incendiary explosive capsule and dampens its explosive effect, and finally provides protection against external mechanical damage to the incendiary explosive capsule.

The connection of differently charged sets of explosives or charges in which the length of the ignition wires is insufficient can be carried out by means of specially made extension ignition holes with a connecting piece at one end and a moisture-proof seal at the other.

The coupling piece (i.e. connecting piece) used in the invention for connecting individual igniters to an ignition system comprises a body, preferably of plastic, provided with a recess for introducing an ignition wire with a shrunken ignitable detonating capsule and one or more igniters. The ignition wires can preferably be inserted into the ignition wire ducts folded twice. The body may also be of the type 57741 mentioned above, but provided with a recess into which the explosive charge is fixedly pressed either directly or by means of a sleeve. The ignition wire is inserted into the recess and the piece is pressed against the ignition wire. The ignition wire channels can be parallel, perpendicular or at a certain angle to the inserted explosive capsule or the fixed explosive charge. The ignition wire channel may also be axially positioned relative to the incendiary explosive capsule. The coupling pieces may have mechanical locking devices, e.g. protrusions, in connection with the ignition wire channel or channels at one end for securing a double-folded ignition wire inserted.

The design in which the ignitable ignition wire is inserted twice folded into the body and in direct contact with the igniting blasting capsule in the parallel direction allows the intensity of the ignitable blasting capsule to be greatly reduced by about 50%, which is of great importance in the case of piercing element. This reduction is achieved by efficiently utilizing the directional component of the shock wave from the ignitable blast capsule to ignite the inserted ignition wire in two diametrical directions.

In order to illustrate the reduction of the specific explosive power which can be achieved when the series is connected to the connection piece according to the invention and the method compared to a known type of explosive ignition wire connection, the following examples can be mentioned: Explosive ignition

Total amount of explosive, calculated in g PETN, which explodes outside the boreholes by igniting a 10-hole set with 2 m spacing 180 g <2.4 g

Some embodiments of the invention will be explained in more detail with reference to the accompanying drawing, in which Figures 1-4 show four alternative coupling structures, Figures 5-7 and 8-13 show two coupling structures consisting of two interconnecting parts, Figure 14 a igniter according to the invention and Figure 15 schematically ignition system in accordance with Reference numerals 57741 5 are the same in all figures.

The coupling pieces comprise a body 1, preferably made of plastic, e.g. polyethylene, with a recess 2 for the insertion of an incendiary explosive capsule connected to an ignition wire, and one or more ignition wire channels 3 for one or more double-folded ignition wires 4. The channels 3 must be arranged in such a way that a part of the ignition wire 4 comes into direct contact with or at a short distance from the detonating capsule. According to Fig. 1, the ignition wire channel 3 is parallel to the explosive capsule recess 2, according to Fig. 2 at a right angle and according to Fig. 3 at an oblique angle to the explosive capsule recess 2. According to Figure 4, the ignition wire channel 3 is arranged axially with respect to the blast capsule recess 2.

Fig. 5 shows a side view of another coupling piece 1, Fig. 6 in section and Fig. 7 in section. The body consists of two interconnectable parts 5 and 6 shown in Fig. 7. The second part 5 is provided with a central recess 2 for the insertion of an incendiary explosive capsule and two parallel ignition wire channels 3 for the insertion of two doubly folded ignition wires 4. To attach the blast capsule, an upper part 6 with a corresponding cavity 2 is used to hold the blast capsule in place. In addition, it has a channel 8 for the passage of an ignition wire connected to an incendiary explosive capsule. The part 6 is further provided with two projections 7, over which the double folded ends of the ignition wire 4 can be attached, see fig. 5 and 6.

Figures 8-13 show another embodiment of the coupling piece 1, comprising two interconnectable parts 5 and 6. The second part 5 is provided with a larger central opening 2 and two smaller openings 3 placed in the bottom, which form part of the ignition wire channels. The part 6 is formed as a piece of plastic and is provided with a central opening 8 into which the explosive charge 10 is pressed down either directly or by means of a sleeve 9. The part 6 is further provided with two parallel recesses 11, which together with the part 5 form the ignition wire channels 3. The projections 7 form members for fixing the doubly folded ignition wires 4. Parts 5 and 6 are joined together and secured by key locking.

Since the pieces according to Figures 5-13 are provided with two channels for the introduction of two ignition wires, the igniters can be extended and also two sets connected in parallel to be ignited.

An example of an embodiment of the igniter described above is shown schematically in Fig. 14, where 9 is an explosive capsule for igniting e.g. an explosive charge in a borehole, 4 is a low energy ignition wire, and includes a piercing element comprising an explosive charge 10. The phrase piercing element forms a common term for a coupling body surrounding an inserted flammable explosive capsule directly shrunk over an ignition wire, or a coupling piece having a fixed explosive charge compressed either directly or by sleeve into a body. In the latter case, the piece is connected directly to the ignition wire.

Figure 15 schematically shows an ignition system using a transfer element according to the invention. The ignitable ignition wire is ignited in a suitable manner as described above. The gas shock wave follows the ignitable ignition wire and ignites the explosive capsule in the transfer element No. 1. In this case, the igniter 1 is pierced and ignited in two directions, in

The couplings, transmission elements and ignition system shown are designed for low-energy ignition wires according to Swedish Patent No. 333,321. The same coupling piece, transfer element and ignition system can also be used for other low-energy ignition wires.

Claims (3)

7 57741 Device for igniting explosive charges, such as for igniting several charges in a series of boreholes, using a low-energy ignition wire, characterized in that the device consists of one or more connecting pieces (1) of non-explosive material, each individual connecting piece being provided with a hole (2) for introducing a low-energy ignition wire into the ignition pulse with an amplifier, e.g. 3), wherein when the initial detonation capsule ignites, it receives and forwards the ignition impulse towards both ends of the ignition wire, and each ignition wire (4) is provided at one end with an explosive capsule to ignite an explosive charge in a borehole and at the other end in the same way as with the initial detonation capsule placed above, in which case, in the same way, the series connection is allowed to detonate an unlimited number of explosive charges in a series of boreholes. Device according to Claim 1, characterized in that the second channel or channels (3) of the connecting piece (1) have mechanical locking means (7) for securing the inserted ignition wires (4). Device according to Claim 1 and / or 2, characterized in that the explosive capsules, the ignition wires (4) and the ignition pulse amplifiers form a closed device with respect to the possible ambient humidity.