FR2840400A1 - SAFETY PRIMER COMPONENT - Google Patents

Abstract

Safety detonator comprises electrodes connected by a fuse in the form of a sheet of a plasmagenic material that generates a gas with a temperature above 15000degreesK and an electron density above 1018/cm3 when a current of at least 5000 A is passed through it.

Description

ter). The technical field of the invention is that of damor components,

  safety cage comprising at least two

electrodes connected by a fuse.

  We know damor components, safety cage for explosives, components which are called "sprayed layer" 1P1US known under the name of "slappers" '). These components include a resistive bridge on which is placed a tube, for example ceramic (or "gun") O An insulating disc is placed between the tube and the resistive bridge. The passage of the electric current in the bridge causes the vaporization of this one, which entralne the cutting of the insulating disc which is projected through the tube. This disc impacts an explosive

catcher that he initiates.

  The advantage of "slappers" is that they can only initiate an explosive when the supply current is applied

  at the electrodes is important (higher than 500 volts).

  Concretely, the operating voltages wind of the order of 3000 volts for a current intensity of the order of 5000 amperes. A voltage lower than 500 volts is insufficient to project the disc and therefore cannot ensure

an initiation.

  It results from these parameters of use a great security which authorizes an alignment of the pyrotechnic chain between the component and the explosive receiving which

  2s is usually a relay in HNS (hexanitrostilbene).

  These initiators, however, have drawbacks.

  First of all they operate with a high operating voltage (3000 volts). This results in problems of electrical insulation which complicate the assemblies as well as

connectivity.

  In addition 'in order to reduce the level of energy used' the resistive bridge is generally of reduced size as well as the ceramic tube (the latter most often has a diameter less than a millimeter). This results in significant production costs which limit the use of such

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  components in civil applications such as

  initiators for automobile safety.

  It is the aim of the invention to provide a priming component, a safety cage not having such drawbacks. The component according to the invention can operate with a reduced voltage (less than or equal to 1000 volts) while

  having a satisfactory level of security.

  Thus, the subject of the invention is a priming component, a safety cage comprising at least two electrodes connected by a fuse, a component characterized in that the fuse is produced in the form of a sheet of a plasmagene material that is ie a material supplying gases at high temperature (greater than 15000 K) and having a high electronic density (greater than 1018 electrons / cm3) when it is traversed by an electric current of at least

5000 amperes.

  According to an essential characteristic of the invention, the fuse material comprises at least one conductive material associated with at least one energetic material or capable of

react with the conductive material.

  The conductive material may be constituted by

carbon or a metal.

  The energetic material or material capable of reacting with the conductive material may be chosen from the following compounds or compositions: Copper oxide; polytetrafluorethylenei copolymer of chlorofluoroethylene; polytetrafluorethylene / chlorofluoroethylene copolymer; Magnesium / polytetrafluorethylene / chlorofluoroethylene copolymer; Boron / Potassium nitrate; plasticized nitrocellulose film or film; polyvinyl nitrate; polyoxymethylene; Trifluoroethylene polychloride; polyvinyl chloride; Polychloride

  trifluoroethylene; polysulfone; polyvinylidene fluoride.

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  According to one embodiment, the fusible sheet may be formed by a homogeneous mixture associating 85% to 95% by mass of particles of conductive material and from 5% to 15% by mass of an energetic material or else capable of reacting with the conductive material

  The fusible sheet may thus have the composition.

  % to 95% by mass of aluminum or magnesium powder,% to 15% by mass of a composition combining

  polytetrafluorethylene and chlorofluoroethylene copolymer.

  The fusible sheet may have the composition:% by mass of aluminum powder,

  % by mass of a composition combining polytetra-

  fluorethylene and chlorofluoroethylene copolymer.

  The fusible sheet may have the composition: 90% by mass of magnesium powder,

  % by mass of a composition combining polytetra-

  fluorethylene and chlorofluoroethylene copolymer.

  According to another embodiment, the fusible sheet may comprise at least one layer of energetic material or else capable of reacting with the conductive material deposited on at least part of a layer of conductive material. The fuse may comprise at least one conductive layer of aluminum or magnesium on which is deposited at least one reactive layer of polytetrafluorethylene, or nitrocellulose or polyvinylf nitrate or copper oxide or of chlorofluoroethylene copolymer, or of polyoxymethylene , or trifluoroethylene polychloride, or polysulfone, or

polyvinylidene fluoride.

  The dimensions of the different layers will be chosen such that 85 to 95% by mass of the material of the conductive layer is combined with 5 to 15% by mass of the material (s) of

the reactive layer (s).

  The fuse may include at least one layer of aluminum or magnesium and at least one layer of

chlorofluoroethylene copolymer.

  The fuse may include at least one layer of magnesium and at least one layer of polytetrafluorethylene. According to a particular mode of real i sat ion / amor component, cage comprises an axial electrode surrounded by a tube of an insulating material itself surrounded by a peripheral electrode, the fusible sheet being applied resting on an end face of the axial electrode and also being in contact with an annular part of the perlpherlque electrode The component may include a chamber for the development of plasma, chamber separated by at least one

electrode by the fusible sheet.

  The room can be delimited by the electrode ... perlpherlque. According to another embodiment, the priming component, the cage may also include a tablet which can be projected through the chamber on the tablet disposed between the

chamber and the fuse sheet.

  The patch can be made of an insulating material

  electric or covered with an electrical insulating layer.

  The pellet can have a diameter between 1 mm and 4 mm and a thickness between 20 and 200 micrometres. According to another embodiment, the amor component, cage may include a housing separated from at least one electrode by the fusible sheet / housing inside

  of which is a pawn projectable by the fusible sheet.

  The pi on can advantageously have the same overall

volume than housing.

  The housing may be delimited by the peripheral electrode and the pin may be made of an electrical insulating material or covered with an electrical insulating layer.

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  According to another embodiment, the axial electrode, the tube of an insulating material and the peripheral electrode may constitute a coaxial cable having a planar end face, and the fusible sheet will then be produced in the form of a layer of plasmagene material. applied

on the end face.

  The layer of plasmagene material can then be constituted by a paint associating a conductive material with a polymerizable binder. The layer of plasmagene material can comprise 70% to% by mass of aluminum, nickel or silver powder.

  with 30% to 10% by mass of an acrylic resin.

  The layer of plasma material may comprise 70% to 90% by mass of aluminum powder, with 30% to 10% by mass

polyurethane.

  The invention will be better understood on reading the

  description which will follow of different embodiments,

  description made with reference to the accompanying drawings and in

  which - Figure 1 is a sectional view of a priming component according to a first embodiment, - Figure 2 is a partial view of an alternative embodiment of the fuse used in the priming component, - the Figure 3 is a sectional view of a priming component according to a second embodiment, - Figure 4 is a sectional view of a priming component according to a third embodiment, - Figure 5 is a view section of a priming component according to a fourth embodiment, - Figure 6 is a sectional view of a component

  initiation according to a fifth embodiment.

  Referring to FIG. 1, a safety initiating component 1 according to the invention is fixed by suitable means (not shown) to an explosive charge 2 comprising an explosive 3 placed in an envelope 40

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  The explosive charge will for example be a relay

  detonation of hexogene in the pulverulent or compressed state.

  As a variant, we could initiate directly without

  relay the explosive charge of a munition.

  Component 1 comprises at least two electrodes 5a and 5b which are connected by a fuse 60. A first axial electrode 5a consists of a metallic cylindrical rod. Wile is surrounded by a tube 7 of an insulating material itself surrounded by a cylindrical peripheral electrode 5bo L4 peripheral electrode 5b therefore has an internal housing 8 which receives the insulating tube 7 and the axial electrode a. This housing 8 is partially closed by an annular rim 9 of the peripheral electrode which has an axial hole lOo The axial hole 10 is arranged opposite another hole 11

  feeding into the casing 4 of the explosive charge 2.

  According to the invention the fuse 6 is made in the form of a sheet of a plasma-producing material, that is to say a material supplying gases at high temperature (greater than 15000 K) and having a high electronic density (greater than 1018 electrons / cm3) when traversed

  by an electric current of at least 5000 amperes.

  This fusible sheet is applied in abutment on an end face 22 of the axial electrode 5a and it is also in contact with the annular part 9 of the electrode.

peripheral 5b.

  The plasma material will comprise at least one conductive material associated with at least one energetic material or

  likely to react with the conductive material.

  By energetic material is meant a material capable of supplying chemical energy in the form of a flame when it is initiated by the joule effect generated by the passage of current in the material.

  driver with whom he is intimately associated.

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  By reactive material or capable of reacting with the conductive material is meant an inert / inert material but capable of reacting chemically with the conductive material when it is heated by the Joule effect. Chemical energy is then provided by this reaction in the form of a flame. The conductive material may be constituted by carbon or by a metal such as copper, aluminum,

silver or magnesium.

  l0 The energetic material or likely to react with the conductive material can be chosen from the following compounds or compositions: Copper oxide, polytetrafluoroethylene; chlorofluoroethylene copolymer; polytetrafluorethylene / copolymer of IS chlorofluoroethylenei Magnesium / polytetrafluorethylene / copolymer of chlorofluoroethylene Bore / potassium nitrate; plasticized nitrocellulose film or film polyvinyl nitrate; polyoxymethylenei Trifluoroethylene polychloridei polyvinyl chloridei Polyvinyl chloride

  trifluoroethylene; polyvinylidene fluoride polysulfoner.

  In this list the energetic materials make the compositions: Magnesium / polytetrafluorethylene / copolymer of chlorofluoro-ethylene Boron / Potassium nitrate; plasticized nitrocellulose film or film

polyvinyl nitrate.

  Reactive materials with a wind conductive material: Copper oxide; polytetrafluorethylenei copolymer of chlorofluoroethylene; polytetrafluorethylene / chlorofluoroethylene copolymer; Polyoxymethylenei Trifluoroethylene polychloride; Polyvinyl chloridei Polysulfone; Polyvinylidene fluoride According to the particular embodiment of FIG. 1, the fusible sheet 6 is formed by a homogeneous mixture associating 85% to 95% by mass of particles of conductive material and 5% to 15% by mass of an energetic material. or

  likely to react with the conductive material.

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  We could for example make a fusible sheet with the following compositions o

Example

  s 85% to 95% by mass of aluminum powder and preferably%% to 15% by mass of a mixture combining polytetrafluorethylene and chlorofluoroethylene copolymer,

and preferably 10%.

Example 2

  % to 95% by mass of magnesium powder and preferably 90%,% to 15% by mass of a mixture associating IS polytetrafluoroethylene and chlorofluoroethylene copolymer,

and preferably 10%.

  We can concretely make the sheet by mixing the metal (aluminum or magnesium) with a solution of

  polytetrafluorethylene and chlorofluoro copolymer

  ethylene in a suitable solvent, for example a ketone: cyclohexyl ketone (cyclohexane) or acetone. The mixture thus produced will be applied as a paint on the face

  end of the axial electrode 5a and of the insulating tube 7.

  Then the solvent will be evaporated before placing the electrode 5a and the insulating tube 7 in the electrode

peripheral 5b.

  Component 1 and connected by conductors 21 and 13 has a

electric generator 14.

  This generator is designed to be able to deliver energy from 10 kJ to 1 megaJoule in the form of voltage pulses from 1000 volts to 20 kilo Volts. Such a generator is conventional and includes for example capacitors, an inductor, switches (such as thyristors or spark gaps) and a stabilized supply "

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  A small fraction of the energy supplied by the generator is used to initiate the fusible sheet 6 by the Joule effect. The energetic material is then initiated or the reaction between the conductive material and the reactive material is initiated. A combustion flame fills the chamber 12 which is constituted by the hole 10 and which is

  delimited by the peripheral electrode 5b.

  This flame is naturally formed from ionized atoms and molecules. D Wile ensures an electrical conduction of reduced resistance between the electrodes 5a and 5b which allows

  maintaining an electric arc between the electrodes.

  Chamber 12 ensures containment of the arc which allows

  the development of the plasma generated by the fusible sheet 6.

  It results in an ounce of very intense shock (combined IS generally with a projection of a part of the fusible sheet) r which impacts the explosive charge 3 through the hole 11 and ensures the initiation of that cf. The pressure generated will be all the more important as

  the volume of chamber 12 will be reduced.

  By way of example, an ignition component has been produced combining a chamber 12 having a volume of approximately 17 mm 3 and an energy fuse of 4 mm effective diameter (diameter of the chamber 12), 90 micrometers thick and having as composition either of the compositions described

2s previously (examples 1 or 2).

  Such a component, supplied under a voltage pulse of 1000 Volts with a maximum intensity of 10000 Amperes, provided the detonation of an explosive relay 11.5mm in diameter and 1115mm high made of hexogen / wax / graphite ( proportions in relative masses: 98/2/1). The pressure obtained at the outlet of the component is

around 1 Giga pascal (1 GPa).

  It is seen that the component according to the invention is easier to manufacture than that of known safety components or "slappers" since it does not require the

2840400

  creation of a resistive bridge and a projection gun

for a lozenge.

  The diameter of the chamber 12 (between 1 and 4 mm) is greater than that of the guns used in known "slappers" (therefore the diameter is generally less than mm) O The supply voltage is also lower (of the order 1000 volts against almost 3000 volts for known slappers). This greatly reduces the insulation problems and therefore facilitates the integration of the component.

  in ammunition or automotive safety systems.

  The electrical power consumed is of the same order as in that of known 'telappers' (10 Mega Watts), the maximum intensity being also higher (approximately 10 kilo Amperes). The component according to the invention is a safety component since the level of energy necessary for its

  initiation meets the requirements given by the standards.

  no pyrotechnic reaction for an impulse of less than 500 volts. It can therefore be used in a diamond-cutting device devoid of means of misalignment of the pyrotechnic chain. It is possible, depending on needs, to play on the different dimensions of the component to define a component operating with a voltage lower than 1000 volts. This will reduce the thickness of the fusible sheet and / or the volume of the chamber 12 to modify the pressure of

  plasma therefore generates the power of the component.

  It is possible, as a variant, to replace the fusible sheet shown in FIG. 1 (in the form of a homogeneous mixture) with a sheet 6 like the one shown in FIG. 2 which comprises a layer 16 of conductive material on which is deposited. at least one layer 15 of an energetic material or capable of

react with the conductive material.

  3s To make such a fuse, we can for example spray a metal sheet with a mixture of glue and

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  energetic material or capable of reacting with the conductive material. Concretely, it is possible to make a fuse comprising an aluminum or magnesium sheet on which is deposited a layer of polytetrafluorethylene or polyvinyl chloride. The thickness of the metallic layer (s) will be of the order of 150 micrometres. That of the energetic material

will be around 100 micrometers.

  i0 We can also associate a layer of aluminum or magnesium with a layer of nitrocellulose or polyvinyl nitrate O We can deposit copper oxide or chlorofluoroethylene copolymer on a sheet

IS of aluminum or magnesium.

  We can also real i ser a deposit of polyoxymethyl ene on a dialuminium layerO In all cases the dimensions of the different layers will be such that 85 to 95% by mass of the material of the conductive layer will be associated with 5 to 15% by mass of the or

  materials of the reactive layer or layers.

  According to a preferred embodiment, a fusible sheet will be produced by depositing at least one layer of chlorofluoroethylene copolymer (known under the trademark Viton) on a layer of aluminum. The relative mass proportions will be 90% for aluminum and 10% for

chlorofluoroethylene copolymer.

  FIG. 3 shows a component according to the invention fitted with a fuse according to FIG. 2. For the simplification of the figure, component 1 has been represented without the explosive charge which it must initiate. The fuse sheet 6 is provided with such so that the metal layer 16 is in contact with the front face

of the axial electrode 5a.

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  The fusible sheet 6 will have a chosen diameter such that the metal layer 16 is also in contact with the

  internal cylindrical surface 8 of the peripheral electrode 5b.

  The current can thus be passed through the conductive layer 16 which will ensure, by Joule effect, the initiation of the reaction with the energetic layer 15 therefore the generation of the plasmaO A component has thus been produced comprising a fuse in the form of a sheet comprising a layer of 80 micrometers thick of aluminum carry a layer of 11 micrometers of chlorofluoroethylene copolymer (known under the trademark Viton). The fusible sheet thus produced has a diameter of 8 mm and the component has a chamber 12

volume about 17 mm3.

  This component could initiate an explosive tablet as described above in response to an impulse of tens ion of

  1000 volts for a maximum intensity of 10 kilo Amperes.

  We also made a geometric component identical to that of the previous one but whose fusible sheet has a layer of 80 micrometers thick of Magnesium carry a layer of 11 micrometers of chlorofluoroethylene copolymer We finally made a geometric component identical to that precedents but whose fusible sheet comprises 2s a layer of 80 micrometers thick of Magnesium carry a layer of 11 micrometers of polytetrafluorethylene (known

under the Teflon trademark).

  These components have also successfully initiated the

  explosive tablet described above.

  In order to initiate less sensitive explosives or to more precisely configure the initiation performance of the component according to the invention, it is possible to define a component also comprising (as in the

  classic slapper components) a projectable tablet.

  3s Figure 4 shows such a component 1.

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  As in the embodiment of FIG. 3, the component 1 comprises two electrodes 5a and 5b which are connected by a fuse 60 The peripheral electrode 5b has an internal housing s 8 which receives an insulating tube 7 and the axial electrode 5a . The housing 8 is partially closed by an annular rim 9 of the peripheral electrode The fuse 6 comprises a conductive layer 16 in electrical contact with a front face of the central electrode 5a and with the internal cylindrical surface of the housing 8. This component differs from that of Figure 3 in that a patch 17 is disposed between the annular flange 9 and the fuse. This patch therefore separates chamber 12 and

the fuse sheet 6.

  IS The patch will be made of an electrical insulating material or covered with an electrical insulating layer. Such an arrangement makes it possible to avoid the amor, cages of electric ares directly between the axial electrode 5a and the pellet. We can for example make the tablet in a plastic material such as a polyimide (material known under the trademark Kapton). We can also make the tablet in mica or in metal (aluminum, titanium or steel). In the case of a metal pellet, it will be covered on both sides with an insulating material, for example 2s polytetrafluoroethylene, or a layer of insulating adhesive tape ensuring an appropriate level of electrical insulation (for example at least 1000 volts ). Such insulating tapes generally use an insulating layer of

  rubber or polyvinyl chloride (PVC).

  Projectable pellets in steel of

at 120 micrometers thick.

  When the current flows through the fuse, the pressure generated by the reaction between the conductive material and the energetic material causes the cutting of the past and its projection through the chamber 12 which thus plays the role.

  from the "canon" of the classic slappers't components.

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  It is therefore not necessary as in known slappers to provide a specific canon component (tube in

  ceramic in the order of mm in diameter).

  The diameter of the chamber can vary between 1 and 4 mm.

  s The Man of the Profession will easily choose the appropriate dimensions to ensure the desired effectO We can especially play on the thickness, therefore the mass of the pellet 'to modify the energy received by the explosive to initiateO By way of example, components incorporating a fuse combining a aluminum layer and a layer of chlorofluoroethylene copolymer (known under the trademark Viton) with the respective weight proportions of

  % and 10% (total thickness of the fuse 100 micrometers).

  Each component has a tablet to be sprayed associated with a chamber with a diameter of 2 or 4mm. The tablet has a thickness of 40 micrometers for steel or 120 micrometers for Kapton. All components led to the initiation of a tablet

  11.5mm x 11.5mm hexogen compressed at 160 MPa.

  The same tests were successfully carried out using a fuse associating a layer of magnesium and a layer of polytetrafluorethylene (known under the trademark Teflon)

  with the respective mass proportions of 90% and 10%.

  Figure 5 shows a component according to a fourth embodiment. This component differs from that according to FIG. 3 in that the chamber 12 constitutes a housing inside of which is a pin 18 projectable by the fusible sheet. The pawn has substantially the same volume as the housing and it fills this one entirely. He is returned

  secured to the component, for example by bonding.

  In order to avoid short circuits between the axial electrode a and the pin, the latter will be made of an insulating material

  electric or in a material covered with an insulator.

  The counter may for example be made of a material

  plastic such as polytetrafluorethylene.

  i5 2840400 L9avantage of such an embodiment is that it generates an ounce of shock which propagates usquta lexplosif through the solid medium of the pion. In all cases must be greater than the critical diameter of the lioxplosive to be initiated. FIG. 6 shows a fifth embodiment of the invention in which the axial electrode 5a r the tube of an insulating material 7 and the peripheral electrode 5b constitute a cable coaxial having a planar end face l9 and an external insulating sheath 20 For example, it is possible to take a commercial coaxial cable of external diameter l, 5 mm, comprising an axial core 5a of 0.2 mm in diameter and a peripheral conductor b forming a wreath 0r2 mm thick. The crown

  insulator 7 will be approximately 100 micrometers thick.

  The face l9 is cut and rectified.

  The fusible sheet 6 is then produced in the form of a layer of plasma material applied to the face.

end l9.

  It is advantageously possible to choose as a plasmagene material a paint associating a conductive material, such as carbon or a metal (aluminum, nickel, copper), with a

  2s polymerizable binder such as polyurethane.

  We could for example associate 70% to 90% by mass of

  aluminum powder with 30% to 10% by mass of polyurethane.

  We will make a fusible sheet of a few micrometers thick simply by coating the end of the

  coaxial cable with the material thus produced then drying.

  We can also associate 70% to 90% by mass of aluminum powder, Nickel or silver with 30% to 10% by mass

of an acrylic resin.

  This embodiment is extremely simple to implement. It also allows to greatly reduce the level

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  of energy required for Reinitiations This level is thus reduced to the order of a few tens of Joules.

  The initiator cable will be made solitary of the charge to be initiated by an appropriate connecting dean, for example a threaded cable clamp which will be screwed onto the envelope of the

  charge next to the explosive charge.

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Claims (18)

RESELL I CAT IONS   1- Component (1) damor, safety cage comprising at least two electrodes (5a, 5b) connected by a fuse (6) D component characterized in that the fuse (6) is produced in the form of a sheet of a material of plasma-forming material ie a material providing gases at high temperature (greater than 15000 K) and having a high electronic density (greater than 1018 electrons / cm3) when it is   lD traversed by an electric current of at least 5000 amperes.   2- Damage component, safety age according to claim 1, characterized in that the material of the fuse (6) comprises at least one conductive material associated with at least one energetic material or capable of reacting with the conductive material.   3- diamor component, safety cage according to claim 2, characterized in that the conductive material   is made up of carbon or a metal.   4- Primer component, safety age according to one of   claims 2 or 3, characterized in that the material   energetic or capable of reacting with the conductive material is chosen from the following compounds or compositions: Copper oxide; polytetrafluorethylene; chlorofluoroethylene copolymer; polytetrafluorethylene / chlorofluoroethylene copolymer; Magnesium / polytetrafluorethylene / chlorofluoro-ethylene boron / potassium nitrate copolymer; plasticized nitrocellulose film or film; polyvinyl nitrate; polyoxymethylene; Trifluoroethylene polychloride; polyvinyl chloride; Polychloride   trifluoroethylene; polysulfone; polyvinylidene fluoride.   - Component of amor, safety cage according to one of the   Claims 2 to 4, characterized in that the sheet   fuse (6) is formed by a homogeneous mixture associating 85% 3s to 95% by mass of particles of conductive material and 5% 18 2840400   at 15% by mass of an energetic material or capable of reacting with the conductive materialO 6- Safety priming component according to claim 5, characterized in that the fusible sheet (6) has the composition:% to 95% by mass aluminum or magnesium powder,% to 15% by mass of a composition combining polytetrafluorethylene and chlorofluoroethylene copolymer 7- Safety priming component according to claim 6, characterized in that the fusible sheet (6) has the composition O % by mass of aluminum powder,   % by mass of a composition combining polytetra-   fluorethylene and chlorofluoroethylene copolymer.   8- Safety initiating component according to claim 6, characterized in that the fusible sheet (6? Has for composition% by mass of magnesium powder,% by mass of a composition combining polytetra   fluorethylene and chlorofluoroethylene copolymer.   9- Safety ignition component according to one of the   Claims 2 to 4, characterized in that the sheet   fuse (6) comprises at least one layer (15) of energetic material or capable of reacting with the conductive material deposited on at least part of a layer (16) of conductive material.   - Safety initiating component according to claim 9, characterized in that the fuse (6) comprises at least one conductive layer (16) of aluminum or magnesium on which is deposited at least one reactive layer (15) of polytetrafluorethylene , or nitrocellulose or polyvinyl nitrate, or copper oxide or chlorofluoroethylene copolymer, or polyoxymethylene, or trifluoroethylene polychloride, or polysulfone, or polyvinylidene fluoride. 19 2840400   11- Damor component, safety cage according to claim 10, characterized in that the dimensions of the different wind layers such that 85 to 95% by mass of the material of the conductive layer is combined to 5 to 15% by mass of the or materials of the reactive layer or layers O 12 Diamor component, safety cage according to claim 11, characterized in that the fuse (6) comprises at least one layer (16) of aluminum and at least one   layer (15) of chlorofluoroethylene copolymer.   13- amor component, safety cage according to claim 11, characterized in that the fuse (6) comprises at least one layer of magnesium and at least one   layer of chlorofluoroethylene copolymer.   14- amor component, safety cage according to claim 11, characterized in that the fuse (6) comprises at least one layer of magnesium and at least one polytetrafluorethylene layer.   - Primer component, safety age according to one of   claims 1 to 14, characterized in that it comprises a   axial electrode (5a) surrounded by a tube (7) of an insulating material itself surrounded by a peripheral electrode (5b), the fusible sheet (6) being applied in abutment on an end face (22) of the axial electrode (5a) and also being in contact with an annular part (9) of 2s the peripheral electrode (5b).   16- starter component, safety cage according to claim 15, characterized in that it comprises a chamber (12) for the development of plasma, separate chamber   at least one electrode by the fusible sheet (6).   17- starter component, safety cage according to claim 16, characterized in that the chamber (12) is   delimited by the peripheral electrode (5b).   18- Amor component, safety cage according to one of the   claims 16 or 17, characterized in that it comprises   also a tablet (17) projectable through the chamber 2840400   (12) / tablet (17) disposed between the chamber (12) and the fuse sheet (61.   19- primer component, safety cage according to claim 18 r characterized in that the patch (17) is made of an electrical insulating material or covered with an electrical insulating layer n damor component, safety cage according to claim 19 , characterized in that the patch (17) has a diameter between 1 mm and 4 mm and a thickness   between 20 and 200 micrometers.   21- component diamor, safety cage according to claim 15, characterized in that it comprises a housing (12) separated from at least one electrode by the fusible sheet (6), housing inside which is disposed a   pin (18) projectable by the fusible sheet (6).   22- component of amor, safety cage according to claim 21, characterized in that the pin (18) has   substantially the same volume as the housing (12).   23- starter component, safety cage according to claim 22, characterized in that the housing (12) is delimited by the peripheral electrode (5b) and in that the pin (18) is made of an electrically insulating material or   covered with an electrical insulating layer.   24- priming component, safety cage according to 2s claim 15, characterized in that the axial electrode (5a), the tube (7) of an insulating material and the peripheral electrode (5b) constitute a coaxial cable having a flat end face (19) r and in that the fusible sheet (61 is produced in the form of a layer of material   plasmagene applied to the end face (19).   - Primer component, safety cage according to claim 24, characterized in that the layer of plasmagene material is constituted by a paint combining a   conductive material with a polymerizable binder.   26- primer component, safety cage according to claim 25, characterized in that the layer of material 2 2840400   plasmagene comprises 70% to 90% by mass of aluminum, nickel or silver powder with 30% to 10% by mass of an acrylic resin 27- Damor component, safety cage according to claim 25, characterized in that the layer of plasma material comprises 70% to 90% by mass of aluminum foil,