GB563345A - Improvements in means for safeguarding electric igniters of blasting detonators against accidental firing - Google Patents
Improvements in means for safeguarding electric igniters of blasting detonators against accidental firingInfo
- Publication number
- GB563345A GB563345A GB1328442A GB1328442A GB563345A GB 563345 A GB563345 A GB 563345A GB 1328442 A GB1328442 A GB 1328442A GB 1328442 A GB1328442 A GB 1328442A GB 563345 A GB563345 A GB 563345A
- Authority
- GB
- United Kingdom
- Prior art keywords
- filter
- core
- igniter
- leads
- igniters
- 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
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B3/00—Blasting cartridges, i.e. case and explosive
- F42B3/10—Initiators therefor
- F42B3/18—Safety initiators resistant to premature firing by static electricity or stray currents
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Elimination Of Static Electricity (AREA)
Abstract
563,345. Lightning arresters. ROLFES, Ltd., ROLFES, H. J., and HALLIDAY, E. C. Sept. 21, 1942, No. 13284. [Class 38 (iv)] [Also in Group XXI] Means for safeguarding electric igniters of blasting detonators against accidental firing by atmospheric electricity comprises the combination of a " filter means" with a self-inductance means, the self - inductance means being located in the igniter and/or blasting circuit leads between the-filter means and the igniter or igniters. By the use of this combination the flow of current caused in the leads by, e.g. lightning discharges, is choked back or prevented from reaching and setting off the igniters. The filter means comprises an earthed mass of a material which will exhibit a high resistance at voltages of the magnitude used for intentionally firing the igniter and a low resistance at substantially higher voltages produced by electrostatic charges caused by atmospheric electricity; such a means is described in Specification 555,969. Fig. 1 shows a copper tube 2 (which is earthed) containing a filter 5 and a self-inductance means 1 in the form of a soft-iron core. The two leads are wound in opposite directions around the legs of the core, so that the two inductances add together. The lead ends 3b, 4b are connected to the igniter. Points 3d, 4d on bared parts of the leads pass through the filter promote passage of current to earth (see Specification 556,071). A rubber plug 10 separates the filter and the core, and rubber plugs 6, 7 close the ends of the tube 2. In modifications, (a) the filter, core and detonator are all contained in an aluminium casing, the filter being earthed by connection to the copper casing of the detonator and to the aluminium casing, and (b) one core may serve for a number of detonators connected together in series or in parallel. The core may be flexible, e.g. it may be made from a length or strands of thin soft iron wire.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1328442A GB563345A (en) | 1942-09-21 | 1942-09-21 | Improvements in means for safeguarding electric igniters of blasting detonators against accidental firing |
US469244A US2411339A (en) | 1941-09-25 | 1942-12-16 | Firing means |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1328442A GB563345A (en) | 1942-09-21 | 1942-09-21 | Improvements in means for safeguarding electric igniters of blasting detonators against accidental firing |
Publications (1)
Publication Number | Publication Date |
---|---|
GB563345A true GB563345A (en) | 1944-08-10 |
Family
ID=10020167
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1328442A Expired GB563345A (en) | 1941-09-25 | 1942-09-21 | Improvements in means for safeguarding electric igniters of blasting detonators against accidental firing |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB563345A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2423377A1 (en) * | 1978-04-18 | 1979-11-16 | Daimler Benz Ag | SYSTEM INTENDED TO RETAIN THE BODY OF PASSENGERS ON VEHICLES |
US4304184A (en) * | 1979-01-15 | 1981-12-08 | Imperial Chemical Industries Limited | Selectively actuable electrical circuit |
CN111536838A (en) * | 2020-05-09 | 2020-08-14 | 无锡力芯微电子股份有限公司 | Electronic detonator and blasting system |
-
1942
- 1942-09-21 GB GB1328442A patent/GB563345A/en not_active Expired
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2423377A1 (en) * | 1978-04-18 | 1979-11-16 | Daimler Benz Ag | SYSTEM INTENDED TO RETAIN THE BODY OF PASSENGERS ON VEHICLES |
US4304184A (en) * | 1979-01-15 | 1981-12-08 | Imperial Chemical Industries Limited | Selectively actuable electrical circuit |
CN111536838A (en) * | 2020-05-09 | 2020-08-14 | 无锡力芯微电子股份有限公司 | Electronic detonator and blasting system |
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