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 firing

Info

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
Application number
GB1328442A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HANS JAY ROLFES
ROLFES Ltd
Original Assignee
HANS JAY ROLFES
ROLFES Ltd
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.)
Filing date
Publication date
Application filed by HANS JAY ROLFES, ROLFES Ltd filed Critical HANS JAY ROLFES
Priority to GB1328442A priority Critical patent/GB563345A/en
Priority to US469244A priority patent/US2411339A/en
Publication of GB563345A publication Critical patent/GB563345A/en
Expired legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42AMMUNITION; BLASTING
    • F42BEXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B3/00Blasting cartridges, i.e. case and explosive
    • F42B3/10Initiators therefor
    • F42B3/18Safety 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.
GB1328442A 1941-09-25 1942-09-21 Improvements in means for safeguarding electric igniters of blasting detonators against accidental firing Expired GB563345A (en)

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)

* Cited by examiner, † Cited by third party
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

Cited By (3)

* Cited by examiner, † Cited by third party
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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