US3124075A - Means for igniting an igniter primer - Google Patents

Means for igniting an igniter primer Download PDF

Info

Publication number
US3124075A
US3124075A US3124075DA US3124075A US 3124075 A US3124075 A US 3124075A US 3124075D A US3124075D A US 3124075DA US 3124075 A US3124075 A US 3124075A
Authority
US
United States
Prior art keywords
anvil
charge
ignition charge
pin
ignition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Other languages
English (en)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication date
Application granted granted Critical
Publication of US3124075A publication Critical patent/US3124075A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
    • F42C19/00—Details of fuzes
    • F42C19/08—Primers; Detonators
    • F42C19/0815—Intermediate ignition capsules, i.e. self-contained primary pyrotechnic module transmitting the initial firing signal to the secondary explosive, e.g. using electric, radio frequency, optical or percussion signals to the secondary explosive
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
    • C06C7/00—Non-electric detonators; Blasting caps; Primers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
    • F42C19/00—Details of fuzes
    • F42C19/08—Primers; Detonators
    • F42C19/10—Percussion caps

Definitions

  • initiating means such as primers, primer cartridges and percussion caps, both for ammunition and other uses have caused a demand for increased sensitivity of the initiating explosives in order to ensure proper functioning.
  • initiation is effected by a pin entering the ignition charge the actual detonation of the ignition is caused by the development of heat due to the friction between the pin and the ignition charge.
  • the sensitivity of ignition charges can be increased by mixing with frictional material such as ground glass or calcium silicide or the friction sensitivity can be increased by the addition of a suitable explosive, e.g. tetrazine.
  • these two types of additions act as diluents and reduce the brisance or strength of the ignition charge.
  • the present invention relates to improvements in initiating means of the impinging type.
  • One object of the improvements is to achieve absolute safety in handling and proper function in operation.
  • a further object of the new initiating means is to reduce the energy necessary to cause initiation and to reduce misfires.
  • the adoption of this new feature enables the tolerances in manufacturing the pin to be increased.
  • Another improvement in the initiating means (described in full detail below) consists in pressing the charge as a layer onto an anvil of hard material. The pin penetrates this layer and strikes the anvil.
  • initiating means embodying the invention is that the percussive effect of the pin against the anvil is used to cause the initial detonation or defiagration so that the thin layer of ignition charge can always be detonated even though it is not of a highly sensitive class. Therefore the device is safe to handle though its effective sensitivity is high.
  • the use of a thin layer of ignition charge on the anvil enables the speed of the ignition to be increased as the path of the pin is short and the kinetic energy lost through penetration of the layer of ignition charge is small.
  • initiation time can be varied between certain limits by varying the thickness of 3,124,075 Patented Mar. 10, 1964 the layer of the ignition charge, on the anvil.
  • the ignition charge layer can, if desired, be free of inert friction material and of highly friction-sensitive explosives.
  • the deflagration or detonation in the initiating means that is, in the thin layer quickly attains its full velocity, i.e. there is good acceleration.
  • the novel initiating means e.g. in the form of a percussion cap is more effective than conventional caps of greater volume in which the initial explosion takes place at a certain depth within the explosive instead of on its surface.
  • the novel initiating means no metal parts are used so that the means is especially useful for anti-tank mines.
  • the novel initiating means are suitable for impact fuses for shells designed to burst on impact on the ground.
  • FIGURE 1 shows the percussion cap and a mine primer in axial section.
  • FIGURE 2 shows another percussion cap for a primer in axial section.
  • the percussion caps of FIGS. 1 and 2 are detonated by a pin 2 and comprise a metallic or a non-metallic capsule 1.
  • the latter contains a secondary or main explosive 5, pressed into the capsule, such as tetryl or trotyl and an ignition charge 4, 4a and priming charge 4b such as dextrinated lead azide, or mercury fulminate.
  • the free surface of the ignition charge 4, 4a is covered by a protecting metallic or non-metallic foil 6 such as a thin aluminum or polythene foil.
  • the capsule is partly sealed by a frontal cover 7 having a central aperture.
  • the ignition charge 4 is arranged adjacent to the main charge 5.
  • the thickness of the layer may, for instance be about 0.5 mm.
  • the anvil can be cylindrical or cubical in form, for instance, and can have a thickness of, for instance, 1 mm.
  • the main charge 5 can be pressed in its place with more force than the ignition charge 4, or vice versa.
  • the desired degree of sensitivity of the cap or initiating means is prirnally determined by the nature of the material of the pin 2 and anvil 3. If both are of steel the sensitivity is relatively low though sufficient for ignition of the ignition charge. At the same time the steel anvil prevents an uncontrolled (in respect of initiation times) explosion deep in the ignition charge. If a steel pin is used with a glass anvil the layer of the ignition charge 4, 4a on the anvil being dextrinated lead azide of a thickness of 0.5 mm., the impact energies are between 800 and 1000 millimetre-grams, While a glass pin on striking a steel anvil under analogous conditions would result in an impact energy of from 300 to 400 millimetre-grams.
  • both pin and anvil are of glass, the conditions being the same, detonation is certain at impact energies as low as 200 millimetre-grams.
  • the sensitivity can be further improved by mat-grinding the glass faces to increase friction on impact.
  • ordinary steel other metallic materials such as brass, stainless steel and sinter metals can be used.
  • glass flint and ceramic materials can be used.
  • the sensitivity of the percussion cap may be further influenced, though to a less degree, by the thickness of the layer 4 on the anvil, the sensitivity increasing with reduced thickness of layer.
  • the necessary impact energy is reduced due to reduced loss of energy on account of the penetration and reduced path of the pin. In all circumstances it is important that the detonation or deflagration should occur on the surface of the anvil which limits the maximum permitted thickness of the ignition layer.
  • the pin 2 In use the pin 2 is moved against the percussion cap and the anvil 3 or vice versa.
  • the protective foil 6 and the ignition layer 4 on the anvil are first pierced.
  • the frictional heat developed between the pin and the ignition charge 4 is not suflicient to initiate this ignition charge 4 owing to the slight thickness of the layer 4, so that the danger of detonations taking place at a shorter time than the desired initiation time will be eliminated.
  • the actual defiagration is started by the direct impact of the pin 2 on the anvil 3.
  • the heat development is utilized while if a glass element is used the heat of splintered-off glass particles on impact plays an important role for distributing the heat energy on impact in the ignition charge. Probably particles are thrown out from the impact zone into the ignition charge at a high velocity.
  • the construction can be used with a transition from more sensitive ignition charges such as undextrinated lead azide with some tetrazene to less sensitive ones, such as dextrinated lead azide.
  • the anvil 3 can be provided with a thin collar or be fixed to an anchoring foil placed in the surface between the main or intermediate charge 5 and the ignition charge 4 to maintain the anvil in its position in the percussion cap during manufacture and also during use.
  • the anvil 3 is shaped so as to secure efliciently that the anvil is maintained in its place in the capsule even when subjected to great acceleration or vibration. This shape also facilitates manufacture of the capsule in small sizes.
  • the anvil 3 here forms a barrier between two layers of the charges 4a and 4b of which a thin ignition layer 4a has been applied to one face of the anvil surface while a thicker priming charge layer 4b supports the anvil 3 and engages the main charge 5.
  • the anvil 3 can be rigidly secured in the capsule 1 of the cap.
  • the anvil 3 in this case serves to transmit an explosive impulse to the underlying priming charge 4b.
  • the anvil 3 and the pin 2 can be made of steel or glass, for instance, according to the desired impact sensitivity.
  • Means for initiating an encapsulated igniter primer comprising in combination, an anvil with flat upper and lower surfaces, a thin layer ignition charge pressed onto said anvil and substantially coextensive in area with the upper surface thereof, the coextensive areas of said ignition charge and said upper surface being in surface to surface contact throughout, a priming charge contacting and substantially coextensive in area with the lower surface of the anvil, the coextensive areas of said priming charge and said lower surface being in surface to surface contact 7 throughout, a pin arranged upon striking to penetrate the made of a metallic material and the pin is made of glass.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Laminated Bodies (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)
US3124075D 1959-11-24 Means for igniting an igniter primer Expired - Lifetime US3124075A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE1106659 1959-11-24

Publications (1)

Publication Number Publication Date
US3124075A true US3124075A (en) 1964-03-10

Family

ID=20293289

Family Applications (1)

Application Number Title Priority Date Filing Date
US3124075D Expired - Lifetime US3124075A (en) 1959-11-24 Means for igniting an igniter primer

Country Status (5)

Country Link
US (1) US3124075A (de)
CH (1) CH413690A (de)
DE (1) DE1115167B (de)
GB (1) GB911587A (de)
NL (2) NL114022C (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3665859A (en) * 1970-05-25 1972-05-30 Catalyst Research Corp Priming device
DE2556179A1 (de) * 1975-12-13 1977-06-23 Hagenuk & Co Gmbh Zuendung in spannabzugzuendern
US4541342A (en) * 1980-05-09 1985-09-17 Emi Limited Pyrotechnic device with metal diaphragm and metal insert

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL300729A (de) * 1962-11-29
US3238876A (en) * 1963-10-08 1966-03-08 Mccormick Selph Associates Inc Method for through-bulkhead shock initiation
FR2528965A1 (fr) * 1982-06-22 1983-12-23 Lcc Cice Cie Euro Composants E Percuteur de mine indetectable
RU2754137C1 (ru) * 2020-09-03 2021-08-30 Российская Федерация, от имени которой выступает Государственная корпорация по атомной энергии "Росатом" (Госкорпорация "Росатом") Устройство взрывное

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US170780A (en) * 1875-12-07 Improvement in primers for cartridges
US183925A (en) * 1876-10-31 Improvement in primers for cartridges
US1333496A (en) * 1918-06-01 1920-03-09 Internat Munitions Company Inc Sensitive ignition device
DE378769C (de) * 1923-08-01 Ernst Ludorf Schlagbolzen fuer Feuerwaffen
US2068516A (en) * 1933-07-14 1937-01-19 Western Cartridge Co Stratified primer charge
US2361955A (en) * 1941-06-27 1944-11-07 Wiley T Moore Explosive bullet
US2398718A (en) * 1942-12-07 1946-04-16 Gen Motors Corp Percussion fuse

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US170780A (en) * 1875-12-07 Improvement in primers for cartridges
US183925A (en) * 1876-10-31 Improvement in primers for cartridges
DE378769C (de) * 1923-08-01 Ernst Ludorf Schlagbolzen fuer Feuerwaffen
US1333496A (en) * 1918-06-01 1920-03-09 Internat Munitions Company Inc Sensitive ignition device
US2068516A (en) * 1933-07-14 1937-01-19 Western Cartridge Co Stratified primer charge
US2361955A (en) * 1941-06-27 1944-11-07 Wiley T Moore Explosive bullet
US2398718A (en) * 1942-12-07 1946-04-16 Gen Motors Corp Percussion fuse

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3665859A (en) * 1970-05-25 1972-05-30 Catalyst Research Corp Priming device
DE2556179A1 (de) * 1975-12-13 1977-06-23 Hagenuk & Co Gmbh Zuendung in spannabzugzuendern
US4541342A (en) * 1980-05-09 1985-09-17 Emi Limited Pyrotechnic device with metal diaphragm and metal insert

Also Published As

Publication number Publication date
NL258304A (de)
NL114022C (de)
GB911587A (en) 1962-11-28
CH413690A (de) 1966-05-15
DE1115167B (de) 1961-10-12

Similar Documents

Publication Publication Date Title
US3611939A (en) Primer
US2972948A (en) Shaped charge projectile
GB1448931A (en) Warhead
US4480551A (en) Point-detonating variable time-delayed fuze
US3499386A (en) Primer
PL193901B1 (pl) Sposób zapalania sprasowanego ładunku udarowego wspłonce, element inicjujący do stosowania w spłonce oraz spłonka
US3124075A (en) Means for igniting an igniter primer
US2400103A (en) Detonator or blasting cap
US2652775A (en) Percussion initiated detonator
US3688702A (en) Detonator device for explosive charge exhibiting detonating effect capable of bridging gap between spaced charges
US3186341A (en) Igniter with separated layers of explosive
US3162127A (en) Delay train for fuze
US5221810A (en) Embedded can booster
US3618523A (en) Stab-electric detonator
US5591935A (en) Shock sensing dual mode warhead
RU2751328C1 (ru) Снаряд с пиротехническим боевым зарядом
US9255777B1 (en) Grenade fuze and detonator with flying disc
US3119336A (en) Fuze for an explosive projectile
US2402235A (en) Blasting initiator
US2857847A (en) Detonators
US3788225A (en) Warhead, particularly for fighting ships
RU2754137C1 (ru) Устройство взрывное
CN108871132A (zh) 一种用于圆筒试验的爆炸自毁装置
US3587466A (en) Relay charge with a fuse of weakened explosive power
US5612505A (en) Dual mode warhead