WO2013059841A1 - Pyrotechnic time delay element - Google Patents
Pyrotechnic time delay element Download PDFInfo
- Publication number
- WO2013059841A1 WO2013059841A1 PCT/ZA2012/000070 ZA2012000070W WO2013059841A1 WO 2013059841 A1 WO2013059841 A1 WO 2013059841A1 ZA 2012000070 W ZA2012000070 W ZA 2012000070W WO 2013059841 A1 WO2013059841 A1 WO 2013059841A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- casing
- time delay
- delay element
- volume
- element according
- Prior art date
Links
- 239000000203 mixture Substances 0.000 claims abstract description 29
- 239000012528 membrane Substances 0.000 claims abstract description 27
- 239000000463 material Substances 0.000 claims abstract description 26
- 239000004033 plastic Substances 0.000 claims abstract description 9
- 229920003023 plastic Polymers 0.000 claims abstract description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 5
- 238000005755 formation reaction Methods 0.000 claims description 5
- 229920001187 thermosetting polymer Polymers 0.000 claims description 4
- 229920001169 thermoplastic Polymers 0.000 claims description 3
- 239000004416 thermosoftening plastic Substances 0.000 claims description 3
- 230000005855 radiation Effects 0.000 claims description 2
- 239000000835 fiber Substances 0.000 claims 1
- 239000002360 explosive Substances 0.000 abstract description 7
- 238000000034 method Methods 0.000 description 6
- 238000001746 injection moulding Methods 0.000 description 5
- 239000004411 aluminium Substances 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007596 consolidation process Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000012815 thermoplastic material Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
- F42C9/00—Time fuzes; Combined time and percussion or pressure-actuated fuzes; Fuzes for timed self-destruction of ammunition
- F42C9/10—Time fuzes; Combined time and percussion or pressure-actuated fuzes; Fuzes for timed self-destruction of ammunition the timing being caused by combustion
Definitions
- This invention relates to a time delay element for use in an explosive application.
- a typical chemical detonator system includes components such as a detonator shell which houses a high explosive base charge, a primary explosive charge and a time delay element.
- the delay element includes an aluminium casing that contains a pyrotechnic delay composition formed from a fuel/oxidiser mixture which, optionally, includes a metal powder or catalyst to control burning characteristics of the composition.
- the composition is press-loaded into the casing during a manufacturing step.
- the aluminium casing is normally manufactured by means of an extrusion process and is relatively expensive.
- the extrusion process results in a casing of a particular cross sectional shape and this poses a constraint on the shape of the composition which is loaded into the casing.
- Another factor is that recent detonator developments have been directed to metal-free systems and, from this point of view, the use of aluminium in making a detonator shell is not always desirable.
- An object of the present invention is to address, at least to some extent, the aforementioned factors.
- the invention provides a pyrotechnic time delay element which includes a casing which is formed from a suitable plastics material, the casing comprising a housing inside which is formed a volume, at least one opening to the volume and a pyrotechnic composition which is loaded into the volume through the opening.
- the pyrotechnic composition may be consolidated inside the volume after it has been loaded into the volume.
- the casing may be formed by means of a suitable moulding process e.g. an injection moulding process.
- the plastics material may be of any appropriate kind and may for example be a thermosetting or thermoplastics material which, optionally, is reinforced e.g. by the inclusion of fibres or which is otherwise treated e.g. by radiation, to enhance its mechanical properties.
- the plastics material may, itself, consist of a mixture of different injection mouldable materials and, optionally, fibres to enhance its properties so as to increase the strength of the material, to reduce the quantity of material required, or the like.
- the housing may be any suitable external cross sectional shape e.g. polygonal or circular, and may be tapered in longitudinal cross section and may have one or more internal or external step formations or the like.
- the housing may have a closed or sealed end which may be formed by the cap or which may be formed integrally with the remainder of the housing.
- the volume, in a longitudinal direction, may have a shape selected from the following: cylindrical, tapered, cylindrical with step formations, and a non-varying cross-sectional shape.
- a membrane may be positioned inside the volume separating an ignition end of the casing from the composition.
- the membrane may have a perforation or opening through it with a shape which, in cross-section, is selected from the following: circular, square, rectangular, cross shaped, star shaped, polygonal.
- the perforation or opening in the membrane, in a longitudinal direction of the casing, may vary in cross-sectional area.
- Figures 1 to 12 are side views in cross section of different casings for use in making a pyrotechnic time delay element, according to the invention
- Figures 13 and 14 show, in cross section, different possible shapes of the casing
- Figures 15 to 18 show, in cross section, different membranes which can be used in a time delay element of the invention
- Figures 19 to 20 are side views of the membrane shown in Figures 15 to 18 respectively.
- Figures 23 to 27 are side views of other possible membranes which can be used in a time delay element according to the invention. DESCRIPTION OF PREFERRED EMBODIMENTS
- the invention is concerned with a non-metallic alternative to a typical metal time delay element casing.
- the casing of the invention is preferably made using injection moulding technology using a suitable plastic material or a mixture of plastic materials.
- the use of injection moulding techniques allows casings of various shapes to be made and also enables inner and outer surfaces of each casing to be varied according to requirement, within reason.
- thermoset or thermoplastic material When making the casing of the invention a suitable thermoset or thermoplastic material is selected. A requirement in this respect is that the chosen material should be capable of being injection moulded into an appropriate shape.
- Thermoset material if chosen, can be reinforced with carbon or glass fibre to achieve satisfactory strength characteristics. The material can also be treated after moulding to improve its mechanical properties.
- a thermoplastics material if chosen, can be reinforced with carbon or glass fibre to enhance its strength.
- Figure 1 illustrates from one side and in longitudinal cross-section a typical casing 10 which is made in accordance with the principles of the invention.
- the casing is moulded from a suitable plastics material and has open opposed ends 12 and 14 respectively.
- the casing is filled with a suitable pyrotechnic composition 20 which is placed using any appropriate technique into an interior of the casing. Thereafter, the composition is press-loaded. Substantial force could be used to consolidate the composition in this way and it is essential therefore that the casing 10 must have sufficient strength not to deform during the consolidation process. Apart from this aspect it is to be borne in mind that when the composition is ignited it may then execute an extended timing interval of the order of seconds. The material which is used in the making of the casing must thus be adequately strong and have appropriate properties to enable the material to withstand the effects of the burning composition.
- Figure 2 illustrates a casing 10 which has been press-loaded with a composition 20, as described in connection with Figure 1 , and wherein opposing ends 12 and 14 are sealed by means of respective closures or caps 22 which are forced into the open ends to achieve a tight sealed fit which ensures that the composition 20 is protected against extraneous factors.
- Figure 3 shows the casing 10, again filled with a composition in the manner described in connection with Figure 1 , wherein a cap 28 is engaged over the open end 12 with an external surface of the casing. Similarly in Figure 4 a second cap 30 is positioned over the opposing end 14.
- the casing 12 shown in Figures 1 to 4 can be circular in cross section (transverse to a longitudinal axis) as is shown, for example, in Figure 13.
- the casing 10 has a polygonal shape.
- Figure 14 depicts an octagonal shape - again this is exemplary only and non-limiting. If the shape is polygonal then this can be in the form of a regular or an irregular polygon, according to requirement.
- Figure 5 shows a casing 40 which has a generally conical external shape 42 and a substantially similar generally conically tapered volume 46 which, in use, is loaded with a pyrotechnic composition.
- Figure 6 shows a casing 48 which has an internal passage 50 of circular cylindrical configuration and an external shape 52 which is tapered. This construction results in one end 54 of the casing having a relatively thick side wall while an opposing end 56 has a thinner side wall.
- Figure 7 shows a casing 60 of compound proportions.
- the casing includes three sections 62, 64 and 66 respectively each of which has a respective internal volume 62A, 64A and 66A respectively. These volumes differ in size from one another. Additionally, walls of the casing designated 62B, 64B and 66B respectively, vary in thickness and hence in strength.
- a different arrangement is embodied in a casing 70 shown in Figure 8.
- the casing has an internal volume 72 of circular cylindrical shape and of constant cross section from one end 74 to an opposing end 76 of the casing.
- a wall of the casing has a stepped configuration.
- An initial portion has a thickness 80
- an intermediate portion has a thickness 82 which is greater than the thickness 80
- a third section of the casing has a thickness 84 of maximum thickness.
- Geometrical variations of this kind i.e. variations in wall thickness, in the length of each wall and in the shape of each passage
- variations such as material types, reinforcements and so on, can all be employed, as appropriate, to obtain specific characteristics in the casing.
- Figure 9 shows a casing 90 which has a regular circular outer shape 92 and an elongate tapered conical passage 94.
- Figure 10 shows a casing 96 which has a stepped internal configuration 98 with a regular circular cylindrical external shape 100.
- Figure 1 shows a casing 102 which has a tapered external shape 104 with a stepped internal configuration 106.
- Figure 12 illustrates an elongate casing 1 10 formed in an appropriate, injection-moulding process.
- the casing in this example, is in the form of a cylinder of circular cross section.
- a primary explosive (not shown) is located preferably in the volume, on the ignition side of the membrane - this is the case for all the examples.
- the membrane may be solid or it may include at least one aperture or perforation of any appropriate shape or size.
- Figure 15 for example illustrates a membrane 112A which has a conical perforation 120 formed through it.
- Figure 19 shows the perforation end-on.
- Figure 16 shows a membrane 112B with a circular perforation 122 and
- Figure 20 shows the perforation end-on.
- Figure 17 shows a membrane 1 12C which has a perforation 124 which in cross section is tapered but which, viewed end-on as is shown in Figure 21 , has a square cross section.
- Figure 18 shows a membrane 112D with a perforation 126 which, in cross section, is generally circular (see Figure 22) although, viewed from one side, the perforation has a semi-spherical shape 128.
- the membrane perforation varies in cross-sectional area.
- FIGs 23 to 27 show different types of formations in various membranes.
- a membrane 130 has a mesh-like configuration.
- a membrane 132 has a slot 134 which is centrally positioned.
- a membrane 136 has a star-like section 138 while, in Figure 26, a membrane 140 is formed with a perforation or aperture 142 which is in the form of half of an annulus.
- a membrane 144 is formed with a cross-shaped perforation 146.
- the various membranes and the cross sectional shapes of the perforation or perforations in the membranes can be used, as appropriate, to shape a wave-front which is propagated by the pyrotechnic composition to ensure that optimum ignition of a primary explosive takes place after the time delay element has executed its timing interval.
- a casing can be made in practically any form, shape or volume with the use of injection moulding techniques. Complex geometrical configurations are possible. These configurations can be used, as appropriate, to ensure that timing intervals are executed with a desired level of accuracy. Additionally, the casings do not make use of metallic sleeves.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Air Bags (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
Claims
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PL12788097T PL2769170T3 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
AP2014007504A AP2014007504A0 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
ES12788097.9T ES2559362T3 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic element with delay |
AU2012325733A AU2012325733A1 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
CA2848612A CA2848612A1 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
EP12788097.9A EP2769170B1 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
US14/352,602 US20140245917A1 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
ZA2014/01724A ZA201401724B (en) | 2011-10-17 | 2014-03-10 | Pyrotechnic time delay element |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ZA201107996 | 2011-10-17 | ||
ZA2011/07996 | 2011-10-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013059841A1 true WO2013059841A1 (en) | 2013-04-25 |
Family
ID=47192241
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/ZA2012/000070 WO2013059841A1 (en) | 2011-10-17 | 2012-10-16 | Pyrotechnic time delay element |
Country Status (11)
Country | Link |
---|---|
US (1) | US20140245917A1 (en) |
EP (1) | EP2769170B1 (en) |
AP (1) | AP2014007504A0 (en) |
AU (1) | AU2012325733A1 (en) |
CA (1) | CA2848612A1 (en) |
CL (1) | CL2014000951A1 (en) |
ES (1) | ES2559362T3 (en) |
PE (1) | PE20142086A1 (en) |
PL (1) | PL2769170T3 (en) |
WO (1) | WO2013059841A1 (en) |
ZA (1) | ZA201401724B (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2944486A (en) * | 1954-01-21 | 1960-07-12 | Hotchkiss Brandt | Self-propelled projectile |
WO2001065200A2 (en) * | 2000-02-28 | 2001-09-07 | Murray Kenneth R | Cartridge format delay igniter |
WO2006086274A2 (en) * | 2005-02-08 | 2006-08-17 | Dyno Nobel Inc. | Delay units and methods of making the same |
WO2007095303A2 (en) * | 2006-02-13 | 2007-08-23 | Dyno Nobel Inc. | Delay elements, detonators containing the same and methods of making |
WO2007110819A1 (en) * | 2006-03-24 | 2007-10-04 | African Explosives Limited | Detonation of explosives |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2436305A (en) * | 1944-02-03 | 1948-02-17 | Remington Arms Co Inc | Ammunition |
US4753170A (en) * | 1983-06-23 | 1988-06-28 | Jet Research Center | Polygonal detonating cord and method of charge initiation |
USH866H (en) * | 1986-07-17 | 1991-01-01 | The United States Of America As Represented By The Secretary Of The Navy | Shaped charge assembly |
US4742773A (en) * | 1986-10-03 | 1988-05-10 | The Ensign-Bickford Company | Blasting signal transmission tube delay unit |
US5031538A (en) * | 1990-02-07 | 1991-07-16 | The Ensign-Bickford Company | Delay train ignition buffer |
US5522318A (en) * | 1990-11-05 | 1996-06-04 | The Ensign-Bickford Company | Cushion element for detonators and the like; apparatus and method of assembly |
KR100576950B1 (en) * | 1997-09-08 | 2006-05-10 | 조디악 오토모티브 유에스 인크. | Distributed charge inflator system |
US6640719B1 (en) * | 1999-01-11 | 2003-11-04 | The United States Of America As Represented By The Secretary Of The Army | Fuze explosive train device and method |
US7951247B2 (en) * | 2002-10-01 | 2011-05-31 | Lawrence Livermore National Security, Llc | Nano-laminate-based ignitors |
US8061273B2 (en) * | 2003-04-30 | 2011-11-22 | Dyno Nobel Inc. | Tubular signal transmission device and method of manufacture |
JP2006140927A (en) * | 2004-11-15 | 2006-06-01 | Sanyo Electric Co Ltd | Radio apparatus, and method and program for controlling transmission |
US7992495B2 (en) * | 2006-03-24 | 2011-08-09 | African Explosives Limited | Detonation of explosives |
DE102008032744B4 (en) * | 2008-07-11 | 2010-04-01 | Junghans Microtec Gmbh | Igniter for a projectile |
-
2012
- 2012-10-16 AP AP2014007504A patent/AP2014007504A0/en unknown
- 2012-10-16 PE PE2014000551A patent/PE20142086A1/en not_active Application Discontinuation
- 2012-10-16 PL PL12788097T patent/PL2769170T3/en unknown
- 2012-10-16 WO PCT/ZA2012/000070 patent/WO2013059841A1/en active Application Filing
- 2012-10-16 ES ES12788097.9T patent/ES2559362T3/en active Active
- 2012-10-16 AU AU2012325733A patent/AU2012325733A1/en not_active Abandoned
- 2012-10-16 CA CA2848612A patent/CA2848612A1/en not_active Abandoned
- 2012-10-16 EP EP12788097.9A patent/EP2769170B1/en not_active Not-in-force
- 2012-10-16 US US14/352,602 patent/US20140245917A1/en not_active Abandoned
-
2014
- 2014-03-10 ZA ZA2014/01724A patent/ZA201401724B/en unknown
- 2014-04-14 CL CL2014000951A patent/CL2014000951A1/en unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2944486A (en) * | 1954-01-21 | 1960-07-12 | Hotchkiss Brandt | Self-propelled projectile |
WO2001065200A2 (en) * | 2000-02-28 | 2001-09-07 | Murray Kenneth R | Cartridge format delay igniter |
WO2006086274A2 (en) * | 2005-02-08 | 2006-08-17 | Dyno Nobel Inc. | Delay units and methods of making the same |
WO2007095303A2 (en) * | 2006-02-13 | 2007-08-23 | Dyno Nobel Inc. | Delay elements, detonators containing the same and methods of making |
WO2007110819A1 (en) * | 2006-03-24 | 2007-10-04 | African Explosives Limited | Detonation of explosives |
Also Published As
Publication number | Publication date |
---|---|
EP2769170A1 (en) | 2014-08-27 |
CL2014000951A1 (en) | 2014-08-08 |
AU2012325733A1 (en) | 2014-04-03 |
US20140245917A1 (en) | 2014-09-04 |
EP2769170B1 (en) | 2015-12-16 |
CA2848612A1 (en) | 2013-04-25 |
ZA201401724B (en) | 2014-12-23 |
AP2014007504A0 (en) | 2014-03-31 |
ES2559362T3 (en) | 2016-02-11 |
PL2769170T3 (en) | 2016-06-30 |
PE20142086A1 (en) | 2014-12-06 |
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