US2331007A - Manufacture of electric detonators - Google Patents

Manufacture of electric detonators Download PDF

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Publication number
US2331007A
US2331007A US321302A US32130240A US2331007A US 2331007 A US2331007 A US 2331007A US 321302 A US321302 A US 321302A US 32130240 A US32130240 A US 32130240A US 2331007 A US2331007 A US 2331007A
Authority
US
United States
Prior art keywords
plug
detonator
electric
wires
vulcanised
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
US321302A
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English (en)
Inventor
Taylor Wilfrid
Jones Maldwyn
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.)
Imperial Chemical Industries Ltd
Original Assignee
Imperial 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 Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Application granted granted Critical
Publication of US2331007A publication Critical patent/US2331007A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F42B3/103—Mounting initiator heads in initiators; Sealing-plugs
    • 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
    • F42B3/103—Mounting initiator heads in initiators; Sealing-plugs
    • F42B3/107—Sealing-plugs characterised by the material used

Definitions

  • Vulcanised indiarubber does not become appreciably plastic when it is exposed to warm temperatures or relatively high pressures such as are experienced in storage. or in blasting Practice, but retains its outstandingresilient properties under these conditions. As long as the material of the plugis in good condition it therefore maintains a continuous pressure against the conductors and the wall of the detonator tube into which it is crimped. So longas the indiarubber remains in good condition, vulcanised indiarub ber plug detonators are thus remarkably free from, the type of failure due to the entry of water orvmoisture.
  • Vulcanised indiarubber As is well known, sooner or later perishes and becomes brittle;- andunder warm storage conditions the life of the vulcanised indiarubber plug electric detonator is somewhat shorter than is generally considered desirable for electric detonjators. For some applications of electric detonators, moreover, especially blasting in' fiery mines, it. is desirable that-the sealing material employed should be of low inflammability, and
  • pounding ingredients of the neoprene composition may include organic ingredients of namequenching, non-inflammable or but slightly in flammable character, for instance, waxy chlorinated hydrocarbons.
  • The'insulated covering of the'electric conductors leadingto the electricinitiating element of the detonator is left intact at the position occupied by the neoprenecomposition plug. 4 According-t0 one form of the invention the neoprene composition is extruded into the form of aperiorated tube before vulcanisation is carried out or completed and the plugs are ia sh-.
  • the neoprene composition in its still thermoplastic unvulcanised oronly partly vulcanised condition is first moulded underpressure at raised temperature around the axially disposed insulated and twisted conductors into a form having a cylindrical surface and is vulcanised thereafter to form structures in which the insulated and twisted leading wires are "firmly embedded in plugs of vulcanised neoprene composition.
  • Fig. 1 is a I longitudinal'section of a charged detonator in plug of neo'prene composition through which the posur'e to warm storage.
  • a tubular neoprene composition plug bearing the insulated conductors to the stripped ends of which a iuzeheadhas been attached, is positioned readyior crimping
  • Fig.2 represents a longitudinal section of the detonator after the plug has been crimped
  • FIG. 1 represents the detonator tube containing an initiating charge 2.
  • 3 represents a cylindrical insulated portions 4 and 5 of; the electric conductors pass.
  • the stripped ends 6 and 'l of these conductors are attached to the poles 8 and 9 of the fuzehead II) by spots of solder II and I2.
  • the resin-wax coating II on the insulated conductors 4 and 6 extends slightly above-the top of the plug.
  • Fig. 2 the general reduction in diamand the corresponding extension in length of the neoprene composition plug are shown.
  • the waterproofing effect depends on the emcient compression by the crimp or the resilient plug eter of the crimped portion of the 'detonator tube severance'ot the leading'wires between the adiace'nt plug's arid the removal or the insulation from their extremities, ii! required, and the attachment oi the primary i electrical ignition means, e. g. the bridge wires or i'uzeheads, may
  • a crimping apparatus especially suitabl for the manufacture of electric detonators according to the present invention first grooves the tube longitudinally around the plug to form a quatre toil section, then flattens the lobes or the quatreioil radially to iorm a' substantially cylindrical neck of reduced radius on the tube;- the superfluone metal being iorced intoa flattened sigmoid told at each side of each groove.
  • the electric, initiating element may convenientlytake the tom of an electric "iuzeheadoi the kind'in which the initiating composition isva coherent bead.
  • the vulcanisable composition may be' vulcanised during the moulding opera-
  • the present invention presents the advantage that theinsulation or thedetonator leading wires may be continued Beyond the plug into the body 01 the detonator, thereby minimiz- "ing the risk of stray current the attachment or a'ready-mads tusehead;
  • the invention in which the vulcanised plug is threaded ontothe insulated conductors the twisting may be carried v s
  • the invention isfurther illustrate ignition and allow Mogiieeium time out before or during the twisting operation.
  • the mouldingoperation mayconveng iently b6 carried out in amultiple unit mould to :produce ,at each operation a number of plugs in which twisted leading wires are' embedded; 'rne lnsiusieii leading wires may be already out and twisted, and i1- deslred also the inculation may beaiready stripped from their ends,
  • the twistedwires may be'in the form of a continuous length 'passingthrough each unit or the mould.
  • the plugs moulded roundthejwisted Vietnamese wires may be removed from the moulds as soonas theyhave set sumci'ently to retaintheirand theivulcanisation-is thereafter accomon the vulcanisation loaded detonator 'tubes are finally crimped around the lugs carrying'the leading wires to. which the primary ignition means have been atn
  • the mould may conveniently be made in two portions each containing a number of. cavities cooperating.
  • the distancing means may be omitted.
  • the mould is provided with arrangements whereby the cavities can be heated, and if desired also it may be provided with means whereby they can be Jchilled.
  • the neoprene composition may be introduced into the cavities in t e form of strips, lumps or the like'in such-quan ty that when'the mouldis closed and pressure i applied the composition will beioroied into intimate contact with the twisted leading wires running axially through the..cavities, and provide an, expess over what is required to complete e cylinder.
  • the detcnator of this example can be used in bomby mines. It can also be used for submarine blasting.
  • Example 2 Quantities of the composition used according to Example 1, each more than sufilcient to form the cylinder, are introduced into the cavities of one plate of a mould of the separable type in which the twisted insulated leading wires have been positioned.
  • the mould cavities are shaped so as to permit surplus material to escape axially at one end to form a flash when the other plate of the mould is pressed home.
  • the temperature of the mould is approximately 160 C. and the mould remains closed under pressure for one minute. It is then opened and the twisted leading wires with their adhering plugs, which have been set in shape by their incipient vulcanisation, are withdrawn.
  • the plugs with the leading wires are then placed in a stove and heated by means of live steam at 40 lb. pressure at approximately 140 C.
  • the diameter of the cylindrical portion of the plugs including the wires is such as to permit of their being just entered without difllculty into a No. 6 detonator tube.
  • the depth of the cylindrical portion or the plug is about 8 mm.
  • the wires are cut at a distance of about from the end of each plug opposite to the flash. The insulation is stripped from the greater part of the short end of the wires and also from the remote ends of the wires. The flash is trimmed. Fuzeheads are then soldered on to the short bared ends and charged No. 6 detonator tubes are crimped around the plugs by means of a Briese crimp.
  • An electric detonator in which the insulated electric conductors leading to the electric initiating element are twisted together and pass through a resilient electric plug comprising vulcanised polymerised 2-chloro-butadiene-1:3 crimped into the mouth of the charged detonator tube.
  • a process for sealing an electric detonator which process comprises positioning about the insulated and twisted electric conductors a sealing plug of resilient material comprising vulcanised polymerised 2-chlorobutadiene-1:3, attaching the electric initiating element, and crimping the plug with the conductors and initiating element in position into the mouth 01. the charged detonator tube.
  • a process as claimed in claim 4 in which a tubular plug of vulcanised 2-chloro-butadiene- 1:3 is first formed and then threaded on to the insulated conductors.
  • a detonator as claimed in claim 1 wherein the tube is crimped to the resilient plug by grooving said tube to form a quatreioil section flatttening the lobes of said quatreioil radially to form a substantially cylindrical neck of reduced radius and forcing the superfluous metal into a flattened sigmoid told at each side of each groove.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Connector Housings Or Holding Contact Members (AREA)
  • Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
US321302A 1939-03-03 1940-02-28 Manufacture of electric detonators Expired - Lifetime US2331007A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7102/39A GB527355A (en) 1939-03-03 1939-03-03 Improvements in or relating to the manufacture of electric detonators

Publications (1)

Publication Number Publication Date
US2331007A true US2331007A (en) 1943-10-05

Family

ID=9826644

Family Applications (1)

Application Number Title Priority Date Filing Date
US321302A Expired - Lifetime US2331007A (en) 1939-03-03 1940-02-28 Manufacture of electric detonators

Country Status (4)

Country Link
US (1) US2331007A (fr)
BE (1) BE438162A (fr)
FR (1) FR863647A (fr)
GB (1) GB527355A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2750831A (en) * 1956-06-19 Method of manufacturing electric blasting caps
US2999460A (en) * 1959-03-02 1961-09-12 Du Pont Electric blasting cap
US4951570A (en) * 1989-07-24 1990-08-28 Joanell Laboratories, Inc. Electrically activated detonator with pyrotechnic device receiving terminals and method of making
US5138948A (en) * 1990-06-15 1992-08-18 Joanell Laboratories, Inc. Hermetically sealed pyrotechnic device
US6505558B1 (en) 1989-10-10 2003-01-14 Joanell Laboratories, Inc. Pyrotechnic ignition apparatus and method
CN111947527A (zh) * 2020-09-03 2020-11-17 贵州全安密灵科技有限公司 一种外接控制模块的新型电子雷管及其加工方法与工具

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2750831A (en) * 1956-06-19 Method of manufacturing electric blasting caps
US2999460A (en) * 1959-03-02 1961-09-12 Du Pont Electric blasting cap
US4951570A (en) * 1989-07-24 1990-08-28 Joanell Laboratories, Inc. Electrically activated detonator with pyrotechnic device receiving terminals and method of making
US6505558B1 (en) 1989-10-10 2003-01-14 Joanell Laboratories, Inc. Pyrotechnic ignition apparatus and method
US5138948A (en) * 1990-06-15 1992-08-18 Joanell Laboratories, Inc. Hermetically sealed pyrotechnic device
CN111947527A (zh) * 2020-09-03 2020-11-17 贵州全安密灵科技有限公司 一种外接控制模块的新型电子雷管及其加工方法与工具

Also Published As

Publication number Publication date
BE438162A (fr)
GB527355A (en) 1940-10-08
FR863647A (fr) 1941-04-05

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