SE1500290A1

SE1500290A1 - Interrupts for a Fuse

Info

Publication number: SE1500290A1
Application number: SE1500290A
Authority: SE
Inventors: Ian Kinley
Original assignee: Ian Kinley
Priority date: 2015-06-26
Filing date: 2015-06-26
Publication date: 2015-06-26
Also published as: SE538822C2

Description

15 20 The invention The present invention is an interrupter isolating the primary explosives from the explosive train. lt is small enough to fit in a hand grenade and fulfils the requirements of an interrupter in the explosive train preventing an unintentional initiation to propagate to the main charge. The unlocking of the interrupter requires an intentional action from the soldier that could be a part ofthe normal arming of the HGR. The interrupter works inside the sealed igniter cartridge isolated from the environmental strains. No physically connected actuators from the outside are required to manoeuvre the interrupter. lvlanoeuvring is done by magnetism. 15 20 The invention The present invention is an interrupter isolating the primary explosives from the explosive train. lt is small enough to fit in a hand grenade and fulfills the requirements of an interrupter in the explosive train preventing an unintentional initiation to propagate to the main charge. The unlocking of the interrupter requires an intentional action from the soldier that could be a part of the normal arming of the HGR. The interrupter works inside the sealed igniter cartridge isolated from the environmental strains. No physically connected actuators from the outside are required to maneuver the interrupter. lvlanoeuvring is done by magnetism.

The present invention is usable in all kinds of munition where a fuse is used. lt increases the safety by unintentional ignition of the ignition train. It is also usable for the same reasons in mining and civil blasting applications.The present invention is usable in all kinds of ammunition where a fuse is used. lt increases the safety by unintentional ignition of the ignition train. It is also usable for the same reasons in mining and civil blasting applications.

Description The igniter has the same basic design as a standard igniter. A delay tube accepts a percussion cap at one end and a detonator at the other. These are sealed as a unit, an igniter cartridge. The delay tube has an axial bore containing a delay charge.Description The igniter has the same basic design as a standard igniter. A delay tube accepts a percussion cap at one end and a detonator at the other. These are sealed as a unit, an igniter cartridge. The delay tube has an axial bore containing a delay charge.

According to the invention as a direct prolongation of the bore there is a barrel.According to the invention as a direct prolongation of the bore there is a barrel.

Inside the barrel a magnetic body is movable arranged. At the end of the barrel a membrane is arranged to seal the barrel from a detonator. 10 15 20 The position of the magnetic body is governed by a magnet on the outside of the unit.Inside the barrel a magnetic body is movable arranged. At the end of the barrel a membrane is arranged to seal the barrel from a detonator. 10 15 20 The position of the magnetic body is governed by a magnet on the outside of the unit.

The movement of the magnet is governed by the arming actions of the HGR, either by the arming mechanism of the HGR as it is thrown or by a separate action by the soldier prior to throw.The movement of the magnet is governed by the arming actions of the HGR, either by the arming mechanism of the HGR as it is thrown or by a separate action by the soldier prior to throw.

At a safe position the magnet influences and keeps the magnetic body on or close to the membrane. The membrane is robust enough to withstand the gas pressure generated by the delay charge and completely stopping any propagation of ignition to the detonator.At a safe position the magnetic influences and keeps the magnetic body on or close to the membrane. The membrane is robust enough to withstand the gas pressure generated by the delay charge and completely stopping any propagation of ignition to the detonator.

At an armed position the magnet moves to influence the magnetic body to move to the top of the barrel close to the delay charge. As the delay charge burns through gas from the delay charge is ínjected into the barrel and thereby accelerating the magnetic body against the membrane. A gain of kinetic energy when accelerated by the gas pressure makes the magnetic body break through the membrane. Hot gas and particles from the delay charge is free to pass through the ruptured membrane and initiate the detonator.At an armed position the magnet moves to influence the magnetic body to move to the top of the barrel close to the delay charge. As the delay charge burns through gas from the delay charge is injected into the barrel and thereby accelerating the magnetic body against the membrane. A gain of kinetic energy when accelerated by the gas pressure makes the magnetic body break through the membrane. Hot gas and particles from the delay charge are free to pass through the ruptured membrane and initiate the detonator.

An alternative to moving the magnet could be moving the igniter. The movement of the magnetic field influencing the magnetic body to shift position could also be done by stationary turning or rotating the magnet whereupon the magnetic field will shift its influence causing the magnetic body to shift position. 10 15 20 lf needed the delay charge could end with a suitable booster in order to create a suitable velocity of the magnetic body and/or create hot particles that propagates through the ruptured membrane initiating the detonator.An alternative to moving the magnet could be moving the igniter. The movement of the magnetic field influencing the magnetic body to shift position could also be done by stationary turning or rotating the magnet whereupon the magnetic field will shift its influence causing the magnetic body to shift position. 10 15 20 lf needed the delay charge could end with a suitable booster in order to create a suitable velocity of the magnetic body and / or create hot particles that propagates through the ruptured membrane initiating the detonator.

To further increase the safety of the interrupter a venting bore for relieving gas pressure generated by the burning of the delay charge can be arranged from either the delay tube or from the barrel. This is done to decrease the pressure on the membrane ifthe delay charge is initiated when the interrupter for a fuse is in a safe state. To prevent an unwanted pressure drop due to unintentional venting of gases in an armed interrupter for a fuse a plug of slowly meltable material can be arranged in the venting bore. To seal the venting bore a plug that melts or dissolves slowly when heated by the delay tube, which is heated by the burning of the delay charge.To further increase the safety of the interrupter a venting bore for relieving gas pressure generated by the burning of the delay charge can be arranged from either the delay tube or from the barrel. This is done to decrease the pressure on the membrane if the delay charge is initiated when the interrupter for a fuse is in a safe state. To prevent an unwanted pressure drop due to unintentional venting of gases in an armed interrupter for a fuse a plug of slowly meltable material can be arranged in the venting bore. To seal the venting bore a plug that melts or dissolves slowly when heated by the delay tube, which is heated by the burning of the delay charge.

Reference numbers 1. Percussion Cap 2. Expansion Space 3. Delay tube 4. Delay charge 5. BOOSTEF 6. Barrel 7. Magnetic body 8. Membrane 10 15 9. Detonator 10. Plug 11. Magnet 12. Hot gases 13. Venting bore 14. ignition charge 15. lgniter cartridge Figures Figure 1 shows the interrupter in un-armed and safe position Figure 2 shows the interrupter in armed position Figure 3 shows the interrupter after ignition in armed state Figure 4 shows detonation Figure 5 shows ignition in the safe position ln figure 1 the interrupter is shown in an un-armed and safe position. The igniter has the same basic design as a standard igniter. A delay tube (3) accepts a percussíon cap (1) at a first end and a detonator (9) at an other and second end. The delay tube (3), the percussíon cap (1) and the detonator (9) are sealed as a unit. The delay tube (3) has an axial bore containing the delay charge (4). As a direct prolongation of the axial 10 15 20 bore there is a barrel (6). Inside the barrel (6) a magnetic body (7) of magnetic material is arranged. At the end of the barrel (6) that is furthest away from the delay charge (4) a membrane (8) stops the magnetic body (7) from further travel towards the detonator. ln the safe position a magnet ( 11) interacts with the magnetic body (7) keeping it close the membrane (8) and to one side where the membrane (8) is strong. An initiation of the ignition train - percussion cap (1), delay composition (4), booster (5) - will not generate enough pressure to rupture the membrane (8) and thus not initiating the detonator (9).Reference numbers 1. Percussion Cap 2. Expansion Space 3. Delay tube 4. Delay charge 5. BOOSTEF 6. Barrel 7. Magnetic body 8. Membrane 10 15 9. Detonator 10. Plug 11. Magnet 12. Hot gases 13. Venting bore 14. ignition charge 15. lgniter cartridge Figures Figure 1 shows the interrupter in un-armed and safe position Figure 2 shows the interrupter in armed position Figure 3 shows the interrupter after ignition in armed state Figure 4 shows detonation Figure 5 shows ignition in the safe position ln figure 1 the interrupter is shown in an un-armed and safe position. The igniter has the same basic design as a standard igniter. A delay tube (3) accepts a percussion cap (1) at a first end and a detonator (9) at an other and second end. The delay tube (3), the percussion cap (1) and the detonator (9) are sealed as a unit. The delay tube (3) has an axial bore containing the delay charge (4). As a direct prolongation of the axial 10 15 20 bore there is a barrel (6). Inside the barrel (6) a magnetic body (7) of magnetic material is arranged. At the end of the barrel (6) that is furthest away from the delay charge (4) a membrane (8) stops the magnetic body (7) from further travel towards the detonator. ln the safe position a magnet (11) interacts with the magnetic body (7) keeping it close the membrane (8) and to one side where the membrane (8) is strong. An initiation of the ignition train - percussion cap (1), delay composition (4), booster (5) - will not generate enough pressure to rupture the membrane (8) and thus not initiate the detonator (9).

The magnetic field from a magnet (11) Iocks the magnetic body (7) in a position close to the membrane (8) where it is unable to move as long as the magnetic field is acting on it in this position.The magnetic field from a magnet (11) Iocks the magnetic body (7) in a position close to the membrane (8) where it is unable to move as long as the magnetic field is acting on it in this position.

The membrane (8) may have different thicknesses making it stronger at the sides and weaker at its centre in order to aid penetration at the centre and to ensure strength at the side where the magnetic body (7) is held, when the igniter is subjected to environmental strains.The membrane (8) may have different thicknesses making it stronger at the sides and weaker at its center in order to aid penetration at the center and to ensure strength at the side where the magnetic body (7) is held, when the igniter is subjected to environmental strains.

The delay charge (4) and the booster (5) may be separate charges or integrated as one single charge, called an ignition charge (14). lf the delay charge (4) is chosen from an explosive that is sufficient to accelerate the magnetic body and initiate the detonator the booster may be excluded from the interrupter and the ignition charge (14) then only consists of the delay charge (4). lf the booster (5) is made from a compound that makes the booster (5) alone sufficient to accelerate the magnetic 10 15 20 body and initiate the detonator the delay charge may be excluded from the interrupter and the ignition charge (14) then only consists of the booster (5). ln applications where no delay is necessary the ignition charge only consists of a booster (5).The delay charge (4) and the booster (5) may be separate charges or integrated as one single charge, called an ignition charge (14). lf the delay charge (4) is chosen from an explosive that is sufficient to accelerate the magnetic body and initiate the detonator the booster may be excluded from the interrupter and the ignition charge (14) then only consists of the delay charge (4). lf the booster (5) is made from a compound that makes the booster (5) alone sufficient to accelerate the magnetic 10 15 20 body and initiate the detonator the delay charge may be excluded from the interrupter and the ignition charge (14) then only consists of the booster (5). In applications where no delay is necessary the ignition charge only consists of a booster (5).

In figure 2 the interrupter is shown in armed position. ln this position the magnetic body (7) has been moved away from the membrane (8) and towards the ignition charge (14) by magnetic force from the magnet (11) and is held in this position by the magnet (11).In figure 2 the interrupter is shown in armed position. ln this position the magnetic body (7) has been moved away from the membrane (8) and towards the ignition charge (14) by magnetic force from the magnet (11) and is held in this position by the magnet (11).

This is accomplished either by moving the magnet in relation to the igniter cartridge (15) or by moving the igniter cartridge (15) in relation to the magnet (11). lt could also be accomplished by rotating or turning a stationary magnet whereupon the magnets' (11) magnetic field will shift its angel influencing the magnetic body (7) causing it to move to a different position.This is accomplished either by moving the magnet in relation to the igniter cartridge (15) or by moving the igniter cartridge (15) in relation to the magnet (11). lt could also be accomplished by rotating or turning a stationary magnet whereupon the magnets' (11) magnetic field will shift its angel influencing the magnetic body (7) causing it to move to a different position.

Figure 3 show how the magnetic body (7) has been accelerated away from it's armed position shown in figure 2. The ignition train comprising percussion cap (1) and ignition charge (14) burns generating hot gases and partícles and a gas pressure is built up in an expansion space (2) and in the delay tube (3). When the ignition charge (14)is fully combusted the pressure will access the barrel (6) and affect the magnetic body (7) acceleratíng it toward the membrane (8).Figure 3 shows how the magnetic body (7) has been accelerated away from it's armed position shown in figure 2. The ignition train comprising percussion cap (1) and ignition charge (14) burns generating hot gases and particles and a gas pressure is built up in an expansion space (2) and in the delay tube (3). When the ignition charge (14) is fully combusted the pressure will access the barrel (6) and affect the magnetic body (7) accelerating it towards the membrane (8).

Figure 4 shows detonation. The magnetic body (7) has gained enough kinetic energy being accelerated through the barrel (6) by the gases from the burning ignition' 10 15 charge (14) to penetrate the middle of the membrane (8). Hot gases and particles will initiate the detonator (9) through the ruptured membrane (8).Figure 4 shows detonation. The magnetic body (7) has gained enough kinetic energy being accelerated through the barrel (6) by the gases from the burning ignition '10 15 charge (14) to penetrate the middle of the membrane (8). Hot gases and particles will initiate the detonator (9) through the ruptured membrane (8).

Figure 5. Shows ignition in safe un-armed position. ln the safe position the magnet (11) interacts with the magnetic body (7) keeping it on or close to the membrane (8) .An initiation of the ignition train - percussion cap (1), delay composition (4), booster (5) - will not generate enough pressure from hot gases (12) to rupture the membrane (8) thus not initiating the detonator (9).Figure 5. Shows ignition in safe un-armed position. ln the safe position the magnet (11) interacts with the magnetic body (7) keeping it on or close to the membrane (8) .An initiation of the ignition train - percussion cap (1), delay composition (4), booster ( 5) - will not generate enough pressure from hot gases (12) to rupture the membrane (8) thus not initiating the detonator (9).

As to further ensure the safety, there could be a venting bore (10) for venting of the overpressure avoiding prolonged pressure exposure to the membrane (8) before cooling down, causing the hot gases volume to decreases. This venting bore (10) bore is preferably sealed with a plug (10) that slowly melts by the heat generated by the delay charge mitigated by the mass of the delay tube (3). The melting material for the plug (10) should be chosen to be slow enough to ensure the intended function of the igniter cartridge in its armed state.As to further ensure safety, there could be a venting bore (10) for venting the overpressure avoiding prolonged pressure exposure to the membrane (8) before cooling down, causing the hot gases volume to decreases. This venting bore (10) bore is preferably sealed with a plug (10) that slowly melts by the heat generated by the delay charge mitigated by the mass of the delay tube (3). The melting material for the plug (10) should be chosen to be slow enough to ensure the intended function of the igniter cartridge in its armed state.

Claims

10 15 20 Int. i. Petem- net registreringsverket 9 2015 -llß- 26. ~ Claims10 15 20 Int. i. Petem- net registriesverket 9 2015 -llß- 26. ~ Claims

1. lnterrupter for a fuse c h a r a c t e r is e d i n that it comprises an ignition charge (14) that consists of a delay charge (4) and/or a booster (5) in a delay tube (3), a magnetic body (7), a membrane (8), a magnet (11), a barrel (6) and a detonator (9), and that said membrane (8) is arranged and sealing between the ignition charge (14) in the delay tube (3) and the detonator (9) to prevent hot gases (12) and particles from the ignition charge (14) to initiate the detonator (9), and that said magnetic body (7) is arranged to be held in a first safe position close to or in contact with the membrane in the barrel by magnetic force from the magnet (11), and that said magnetic body (7) also is arranged to be moved to and held in a second active position by the magnet (11) and that the magnetic body (7) from this second position can be accelerated toward the membrane (8) by gases produced by the ignition charge (14) and penetrate the membrane (8) to allow the hot gases (12) and particles from the ignition charge (14) to pass through the ruptured membrane (8) and initiate the detonator (9).1. lnterrupter for a fuse character is edin that it comprises an ignition charge (14) that consists of a delay charge (4) and / or a booster (5) in a delay tube (3), a magnetic body (7), a membrane (8), a magnet (11), a barrel (6) and a detonator (9), and that said membrane (8) is arranged and sealing between the ignition charge (14) in the delay tube (3) and the detonator (9) to prevent hot gases (12) and particles from the ignition charge (14) to initiate the detonator (9), and that said magnetic body (7) is arranged to be held in a first safe position close to or in contact with the membrane in the barrel by magnetic force from the magnet (11), and that said magnetic body (7) also is arranged to be moved to and held in a second active position by the magnet (11) and that the magnetic body (7) from this second position can be accelerated toward the membrane (8) by gases produced by the ignition charge (14) and penetrate the membrane (8) to allow the hot gases (12) and partic les from the ignition charge (14) to pass through the ruptured membrane (8) and initiate the detonator (9).

2. lnterrupter fora fuse according to claim 1 c h a r a c t e r is e d i n that the ignition charge (14) consists of a delay charge.2. lnterrupter fora fuse according to claim 1 c h a r a c t e r is e d i n that the ignition charge (14) consists of a delay charge.

3. lnterrupter for a fuse according to claim 1 c h a r a c t e r i s e d I n that the ignition charge (14) consists of a booster.3. lnterrupter for a fuse according to claim 1 c h a r a c t e r i s e d I n that the ignition charge (14) consists of a booster.

4. lnterrupter for a fuse according to any of the preceding claims c h a r a c t e r i s e d i n that a venting bore (13) for relieving gas pressure generated by the burning of the ignition charge is arranged from either the delay 10 15 20 10 tube (3) or from the barrel (6) and that the venting bore (13) is provided with a plug (10) made of a meltable material that melts from heat and thereby prevents pressure build up in case of unintentional burning ofthe igniting charge.4. lnterrupter for a fuse according to any of the preceding claims characterizedin that a venting bore (13) for relieving gas pressure generated by the burning of the ignition charge is arranged from either the delay 10 15 20 10 tube (3) or from the barrel (6) and that the venting bore (13) is provided with a plug (10) made of a meltable material that melts from heat and thereby prevents pressure build up in case of unintentional burning ofthe igniting charge.

5. lnterrupter for a fuse according to any of the preceding claims c h a r a c t e ris e d in that the membrane (8) is weaker at its centre to ensure that the magnetic body (8) penetrates the membrane (8) when the magnetic body (8) has been accelerated towards the membrane (8) when the igniter cartridge is armed its armed state and/or that said membrane is stronger towards the side magnetic body (8) is held to ensure that the magnetic body (8) doesn't break the membrane due to environmental strains.5. lnterrupter for a fuse according to any of the preceding claims characte ris ed in that the membrane (8) is weaker at its center to ensure that the magnetic body (8) penetrates the membrane (8) when the magnetic body (8) has been accelerated towards the membrane (8) when the igniter cartridge is armed its armed state and / or that said membrane is stronger towards the side magnetic body (8) is held to ensure that the magnetic body (8) does not break the membrane due to environmental strains.

6. lnterrupter for a fuse according to any of the preceding claims c h a r a c t e ris e d in that the magnet (11) is arranged to be adjustable in order to affect the position of the magnetic body (7).6. lnterrupter for a fuse according to any of the preceding claims c h a r a c t e ris e d in that the magnet (11) is arranged to be adjustable in order to affect the position of the magnetic body (7).

7. lnterrupter for a fuse according to any of the preceding claims c h a r a c t e r i s e d i n that the moving of the magnetic body (8) away from the membrane and towards the ignition charge (14) by magnetic force from the magnet (11) is accomplished by moving the magnet in relation to the igniter ca rtridge.7. lnterrupter for a fuse according to any of the preceding claims characterizedin that the moving of the magnetic body (8) away from the membrane and towards the ignition charge (14) by magnetic force from the magnet (11) is accomplished by moving the magnet in relation to the igniter ca rtridge.

8. lnterrupter for a fuse according to any of claim 1-6 c h a r a c t e r is e d i n that the moving of the magnetic body (8) away from the membrane and towards the ignition charge (14) by magnetic force from the 10 15 11 magnet (11) is accomplished by moving the igniter cartridge in relation to the magnet.8. lnterrupter for a fuse according to any of claim 1-6 character is edin that the moving of the magnetic body (8) away from the membrane and towards the ignition charge (14) by magnetic force from the 10 15 11 magnet (11 ) is accomplished by moving the igniter cartridge in relation to the magnet.

9. lnterrupter for a fuse according to any of claim 1-6 c h a r a c t e r is e d i n that the moving of the magnetic body (8) away from the membrane and toward the ignition charge (14) by magnetic force from the magnet (11) is accomplished by moving the magnet in relation to the igniter ca rtridge.9. lnterrupter for a fuse according to any of claim 1-6 character is edin that the moving of the magnetic body (8) away from the membrane and toward the ignition charge (14) by magnetic force from the magnet (11) is accomplished by moving the magnet in relation to the igniter ca rtridge.

10. lnterrupter for a fuse according to any of claim 1-6 c h a r a c t e r i s e d i n that the movement of the magnetic field influencing the magnetic body (8) to shift position is done by stationary turning and/or rotating the magnet (11) whereupon the magnetic field wíli shift its influence causing the magnetic body (8) to shift position.10. lnterrupter for a fuse according to any of claim 1-6 characterizedizedin that the movement of the magnetic field influencing the magnetic body (8) to shift position is done by stationary turning and / or rotating the magnet (11) whereupon the magnetic field wíli shift its influence causing the magnetic body (8) to shift position.