US3874293A - Fuses and cords - Google Patents

Fuses and cords Download PDF

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Publication number
US3874293A
US3874293A US359122A US35912273A US3874293A US 3874293 A US3874293 A US 3874293A US 359122 A US359122 A US 359122A US 35912273 A US35912273 A US 35912273A US 3874293 A US3874293 A US 3874293A
Authority
US
United States
Prior art keywords
fuse
semi
fuses
core
cords
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
US359122A
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English (en)
Inventor
Peter Charles Seligmann
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.)
AE and Ci Ltd
African Explosives and Chemical Industries Ltd
Original Assignee
African Explosives and Chemical Industries 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 African Explosives and Chemical Industries Ltd filed Critical African Explosives and Chemical Industries Ltd
Application granted granted Critical
Publication of US3874293A publication Critical patent/US3874293A/en
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
    • C06C5/00—Fuses, e.g. fuse cords

Definitions

  • the fuses and cords are of Circular m. cross-section, so that standard size detonator tubes [5 ledo earc can be used to makeqfor examplefiapped fuse- [561 References Cited It is expected that the m llt i-core fuses and cords have UNITED STATES PATENTS better burmng characterlsncs.
  • two or more fuses or cords are often used in practice so that. if one of these fails, the other fuse or cord will ensure initiation of the explosive charges. This is particularly important in sequential blasting techniques where one failure will interrupt the sequence of the blast.
  • the use of two or more fuses or cords is, however. not generally acceptable because of the extra costs and work involved.
  • Fuse-cords are generally manufactured by first making a semi-fuse comprising a core of an incendiary com position enclosed in a protective casing made of textile material or paper.
  • the semi-fuse is then covered by an outer coating of impermeable material such as bitumen, rubber and synthetic plastic materials.
  • a plural core fuse for use in initiating explosives which comprises at least two lengths of semi-fuse parallel to each other and enclosed within an outer casing.
  • the semi-fuses used in the fuse according to the invcntion contain charges of incendiary composition
  • the total charge of the two or more parallel semi-fuses of the fuse according to the invention may be more than the charge of a single core fuse.
  • the fuse according to the invention preferably has a circular cross-section and the parallel semi-fuses contained therein will have a cross-section of irregular shape so that their cross-sections when added together form a circular cross-section. Possible voids between the irregular shapes may be filled with, for example, filler yarns.
  • the outer casing can be made of any suitable material which preferably is impermeable to moisture. Suitable materials include bitumens, rubber and synthetic plastics.
  • the outer casing may be made by applying more than one coating onto the core so that a layered outer casing is obtained.
  • these materials may be applied by extruding the casing onto the core.
  • FIG. I of the drawings shows a cross-section of a double core fuse and FIG. 2 shows a cross-section of a triple core fuse.
  • the core of a double core fuse 10 comprises two semi-fuses each having an incendiary charge 11 contained in a protective coating of textile material 12.
  • the two semi-fuses are contained in a circular outer casing consisting of two layers 13 and 14 of impermeable materials, whereof the layer I4 is an extruded plastics material.
  • the core of fuse 20 comprises three semifuses each having an incendiary charge 11 contained in a protective coating of textile material 12.
  • the three semi-fuses are contained in a circular outer casing as in FIG. I.
  • the cross-sectional shapes of the semi-fuses vary in FIGS. 1 and 2 and are respectively equal to halfa circle and a third of a circle.
  • the outer shapes are obtained by forming a circular outer casing around the semifuses.
  • the voids defined by the outer casing and the semi-fuses may be filler yarns 15 as shown.
  • the plural core fuses or cords of the present invention have the following advantages over the use of two fuses or cords in blasting practice. They are cheaper than two fuses or cords and require less work to connect at the blasting site. They give the same added accuracy of burning speed and safety against failure as the use of two cords since the semi-fuses are individually manufactured and any failures and irregularities in burning speed in one semi-fuse will be smoothed out by the other semi-fuse or semi-fuses in the core.
  • the circular cross-section is advantageous in that the fuses of the invention can be used with standard size detonator tubes to make capped fuses without the necessity to manufacture oversized detonator tubes.
  • a plural core non-detonating incendiary fuse for use in initiating explosives said fuse having at least two contacting parallel lengths of semi-fuse, the crosssection of the lengths of semi-fuse when added together forming a substantially circular cross-section, each of said contacting parallel lengths of semi-fuse having a core of incendiary composition, said semi-fuses being enclosed within an outer casing thereby forming a plural core incendiary fuse of circular cross-section.
  • a fuse as claimed in claim 1 wherein the semi-fuse has a charge of incendiary composition which is less than the charge used in a single core fuse.
  • a fuse as claimed in claim 5 wherein the moisture impermeable material is selected from bitumen, rubber and synthetic plastics material.
  • a fuse as claimed in claim 1 adapted for use with standard size detonator tubes.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Fuses (AREA)
US359122A 1972-05-18 1973-05-10 Fuses and cords Expired - Lifetime US3874293A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
ZA723384A ZA723384B (en) 1972-05-18 1972-05-18 Improvements in fuses and cords

Publications (1)

Publication Number Publication Date
US3874293A true US3874293A (en) 1975-04-01

Family

ID=25564875

Family Applications (1)

Application Number Title Priority Date Filing Date
US359122A Expired - Lifetime US3874293A (en) 1972-05-18 1973-05-10 Fuses and cords

Country Status (7)

Country Link
US (1) US3874293A (fr)
BE (1) BE799779A (fr)
CA (1) CA998291A (fr)
FR (1) FR2184978A1 (fr)
GB (1) GB1374403A (fr)
IT (1) IT987694B (fr)
ZA (1) ZA723384B (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2441598A1 (fr) * 1978-11-20 1980-06-13 Explosive Tech Meche d'allumage

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2113004A (en) * 1936-05-13 1938-04-05 Trojan Powder Co Detonating fuse
US2239052A (en) * 1939-03-16 1941-04-22 Ensign Bickford Co Rapid igntion device for use with safety fuses or the like
US2498050A (en) * 1947-07-31 1950-02-21 Selvidge Harner Fulminating fuse
US2877708A (en) * 1955-07-08 1959-03-17 Rey Freres & Cie Ets Detonating fuse
US3041914A (en) * 1958-02-19 1962-07-03 Ici Ltd Delay fuse elements for delay electric detonators and delay electric detonators containing them
US3320883A (en) * 1965-09-03 1967-05-23 Canadian Safety Fuse Company L Explosive tape
US3367266A (en) * 1966-09-01 1968-02-06 Commercial Solvents Corp Detonating and deflagrating fuse
US3590739A (en) * 1967-07-20 1971-07-06 Nitro Nobel Ab Fuse

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2113004A (en) * 1936-05-13 1938-04-05 Trojan Powder Co Detonating fuse
US2239052A (en) * 1939-03-16 1941-04-22 Ensign Bickford Co Rapid igntion device for use with safety fuses or the like
US2498050A (en) * 1947-07-31 1950-02-21 Selvidge Harner Fulminating fuse
US2877708A (en) * 1955-07-08 1959-03-17 Rey Freres & Cie Ets Detonating fuse
US3041914A (en) * 1958-02-19 1962-07-03 Ici Ltd Delay fuse elements for delay electric detonators and delay electric detonators containing them
US3320883A (en) * 1965-09-03 1967-05-23 Canadian Safety Fuse Company L Explosive tape
US3367266A (en) * 1966-09-01 1968-02-06 Commercial Solvents Corp Detonating and deflagrating fuse
US3590739A (en) * 1967-07-20 1971-07-06 Nitro Nobel Ab Fuse

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2441598A1 (fr) * 1978-11-20 1980-06-13 Explosive Tech Meche d'allumage
US4220087A (en) * 1978-11-20 1980-09-02 Explosive Technology, Inc. Linear ignition fuse

Also Published As

Publication number Publication date
CA998291A (en) 1976-10-12
IT987694B (it) 1975-03-20
BE799779A (fr) 1973-11-19
FR2184978A1 (fr) 1973-12-28
ZA723384B (en) 1974-01-30
GB1374403A (en) 1974-11-20

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