Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C19/00—Details of fuzes
  • F42C19/06—Electric contact parts specially adapted for use with electric fuzes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C14/00—Mechanical fuzes characterised by the ammunition class or type
  • F42C14/04—Mechanical fuzes characterised by the ammunition class or type for torpedoes, marine mines or depth charges
  • F42C14/045—Mechanical fuzes characterised by the ammunition class or type for torpedoes, marine mines or depth charges having electric igniters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C15/00—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges
  • F42C15/28—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges operated by flow of fluent material, e.g. shot, fluids
  • F42C15/285—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges operated by flow of fluent material, e.g. shot, fluids stored within the fuze housing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C15/00—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges
  • F42C15/34—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges wherein the safety or arming action is effected by a blocking-member in the pyrotechnic or explosive train between primer and main charge
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C19/00—Details of fuzes

Definitions

• the invention relates to an arming device for sea mines, comprising an electric detonator, a transfer charge and an -interruptor which can be introduced between the detonator and the transfer charge to separate the detonator and the transfer charge from each other.
• the explosive system, the explosive train, of a sea mine typically can be built up by an electric detonator, containing some 50 mg of a high sensitive explosive such as si 1ver-azide, and some 60 mg of e.g. PETN, a transfer charge containing a few grammes of tetryl or similar, a booster charge containing say 1 kg of RDX/TNT or similar, and a main charge containing say 100 - 600 kg of TNT or si i1ar. From the safety point of view one makes a distinc ⁇ tion between explosives more sensitive than tetryl (e.g. si 1 ver-azide) and explosives which have a sensitivity equal to or lower than that of tetryl.
• a high sensitive explosive such as si 1ver-azide
• PETN e.g. PETN
• a transfer charge containing a few grammes of tetryl or similar
• a booster charge containing say 1 kg of RDX/TNT
• explosives more sensitive than tetryl normally should be prevented from trans ⁇ ferring a detonation by means of a physical obstruction (interruptor), so that the explosive train is positively interrupted by mechanical means until arming is required. Then, the physical obstruction should remain positively locked in the safe position under all envisaged environ ⁇ mental conditions other than those for correct operation.
• the arming device of a sea mine thus should keep
• the arming device also has another function: it shall operate electric switches in a programmed sequence, by which the batteries of the mine are connected to the electronic system of the mine shortly after launching and the electric detonator is kept short- -circuited alternatively completely disconnected and is connected to the firing system of the mine shortly before arming.
• Known arming devices generally are designed such that the detonator is mounted in connection with the assembly of the device and afterwards is no longer accessible from the outside of the mechanism (the mine) , i.e. the detonator after mounting forms an integral part of the arming device.
• the detonator and the booster charge must not be present in the mine simultaneously during storage and transport (during peace time) .
• one mine manufacturer has designed the mine in such a way that the booster charge is easily accessible and can be stored outside the mine then to be quickly inserted in connection with the preparation of the mine for combat. This is, however, not a practical solution due to the fact that a separate storage room for the booster charges is required, which should be well separated from the room wherein the mines are stored.
• FIG. 1 is a vertical cross-sectional view of the arming device mounted to a mine, the section being taken along line I - I in FIG. 2 and the device being shown in the safe condition thereof
• FIG. 2 is a plan view of the arming device with some parts thereof shown in cross section along the plane of the lower side of the cover of the device
• FIG. 3 is an elevational view, partly a cross- -sectional view, of the detonator unit, separated from the arming device, in the embodiment shown in FIGS. 1 and 2,
• FIG. 4 is an elevational view of the detonator unit in another embodiment thereof with said unit inserted into the housing which is shown in axial cross-sectional view, and
• FIG. 5 is a fragmentary elevational view of the arming device, which discloses a modified embodi ⁇ ment of the actuating means of the interruptor.
• a sea mine comprises a casing 10 containing a main charge 11.
• the casing 10 forms a space 12 which is the instrument housing of the mine, the arming device of the mine being located therein.
• This device comprises a bottom plate 13 and a cover 14, the bottom plate and the cover being inter ⁇ connected by means of cantilever beams 15.
• a transfer charge 16 is located, and below the bottom plate a booster charge 17 is located.
• a housing 18 fixedly connected therewith and having an axially through bore 19 for receiving a detonator unit 20 therein, said unit being shown separately in FIG. 3. It comprises a telescopic shaft consisting of a tube 21 and another element 22 displaceably received therein, which forms the detonator proper.
• the element 22 is biased by means of a pressure ring 23 received in the tube 21, and dis ⁇ placement of said element in the tube is limited by means of a cross pin 24 passing through the element 22 and extending into axial slots 25 in the tube 21.
• the interruptor 34 can be made of solid metal but preferably it comprises a sandwich structure which is made up of different materials, some being effective for absorbing particle flow from the detonator charge 26 if it detonates, and others being effective for attenuating the propagation of the detonation wave.
• the interruptor is fixedly connected with a housing 35, the interruptor and the housing being journalled on a pin 36 attached to the bottom plate 13, for rotational movement about a vertical axis.
• a clock spring 37 is provided, which is not tensioned normally and thus exerts no torque on the housing 35 and the interruptor 34 connected there- with.
• the inner end of the spring is attached to a spindle 38 which is rotatably mounted in the housing 35 and also in a partition 39 supported by the conti- lever beams 15.
• the housing 35 and the interruptor 34 define a space 40 which is filled wi h silicon oil of high
• OMPI_ viscosity and a disc 41 is received by said space.
• the disc is non-rotatably but axially displaceably connected with the journal pin 36 by the pin 42 being inserted into the disc 41 as well as the journal pin 36.
• a recess 43 in which there is located a helical pressure spring 44 biasing the disc 41 towards a distance element arranged between the disc and the interruptor 34 such that there exists between the disc 41 and the interruptor 34 a gap of a predetermined size and there exists a gap also between the disc 41 and the housing 35.
• These gaps should be of the order 0.1 mm and are filled with the silicon oil contained in the space 40.
• the disc 41 located in the space 40 and the silicon oil form a viscosity brake for retarding the rotation of the interruptor 34 under the bias of the spring 37 when tensioned.
• the spring is tensioned by means of a hydrostatic starting device which will now be described in more detail.
• the piston is biased by means of a pre-tensioned pressure spring 51 in the cylinder bore 47 and is connected with a nut 52 non-rotatably but axially displaceably mounted, which engages a screw- -threaded portion 53 of the spindle 38.
• a roll membrane 54 forms a sealing between the piston 46 and the cover 14 in the cylinder bore 47.
• An arm 55 on the nut 52 can be engaged with an abutment 56 on a projecting arm 57
• the screw-threaded portion 53 has such a pitch that the spindle will be rotated to tension the spring 37 by axial displacement of the nut 52 downwards along the spindle 38 while the housing 35 and the interruptor 34 are held stationary by the abutment 56 engaging the arm 55 on the nut 52.
• the separately stored detonator unit 20 When preparing the mine for combat the separately stored detonator unit 20 is inserted into the cylinder bore 19 in the housing 18, the telescopically arranged detonator unit being compressed against the bias of the spring 23 when the detonator unit is engaged with the interruptor 34.
• the detonator unit will be maintained in the position thereof by means- of the screwed-on cap 32, and the 0-rings 33 prevent sea water from penetrat- ing into the cylinder bore 19 when the mine is sinking.
• the contacts 3Q and 31 do not engage the contacts 28 and 29, respecti ely.
• the interruptor 34 is positively secured in the position shown, wherein the interruptor keeps the detonator charge 26 separated from the transfer charge 16 by the piston 46 and thus the nut 52 by means of the inserted safety pin 50 being held in the shown upper position thereof, in which the housing 35 and thus the interruptor 34 are held in the rotated position shown by the engagement of the arm 55 and the abutment 56.
• the spring 37 under the circumstances is not tensioned such that there is exerted no torque on the housing 35 and the " nterruptor 34, respectively.
• the detonator unit accordingly can be mounted at any time before the mine is launched; also after mounting of the detonator unit the safety is fully guaranteed.
• the spring 37 will be tensioned by the rotation of the spindle and thus will exert a torque on the housing 35 and accordingly on the interruptor 34.
• no rotation of the interruptor will take place because such rotation will be prevented by the engagement between the arm 45 and the abutment 46 but only initially under the movement of the piston 46, because the arm 55 during the axial movement of the nut 52 downwards eventually w ll disengage the abutment 56 so that the housing 35 and the interruptor 34 will be released for rotation under the action of the tensioned spring 37.
• This can take place e.g. at a depth of 5 , and the rotation of the spindle 38 thus effected may be of the order of 1/2 - 1 revolu ⁇ tion.
• connection of the batteries of the mine to the electric or electronic system of the mine and a micro-switch 60 actuated by the interruptor 34 when it is close to the completely withdrawn position thereof, e.g. to cause interruption of short-circuiting of the detonator, if any, and/or connection of the detonator electrically to the ignition system of the ine.
• the chamber 47 in the position shown is connected with the much larger space 12 (the instrument housing of the mine) by means of an air passage 66.
• this passage there is mounted with proper axial friction a pin 67.
• the pin normally does not prevent air exchange between the chamber 47 and the space 12 but if the pin 67 is depressed, which takes place when the piston 46 moves downwards to the bottom position thereof, an 0-ring 68 on the pin 67 closes the air passage 66 and then the chamber 47 will be completely sealed against the space 12.
• the piston 46 will start a slow motion upwards.
• the speed will be determined by the flow through the choking aperture 61, which in turn is dependent on the pressure difference over the choking aperture, which as mentioned above is independent of the surrounding water pressure (determined by the spring bias and the piston area only, if existing frictional forces are neglected) .
• Tne advantage of the principle now described over the viscosity brake principle is that the arming time will be independent of temperature.
• the viscosity of a silicon oil in fact varies with the temperature such that the arming time when mines are launched in hot weather may be of the order 50 % shorter than the arming time at launching in cold weather.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Ocean & Marine Engineering (AREA)
• Air Bags (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20348212

Family Applications (1)

Country Status (5)

Cited By (3)

Families Citing this family (2)

Citations (4)

Family Cites Families (5)

• 1982
  • 1982-10-15 SE SE8205855A patent/SE444985B/sv not_active IP Right Cessation
• 1983
  • 1983-10-13 EP EP83903235A patent/EP0141812B1/en not_active Expired
  • 1983-10-13 DE DE8383903235T patent/DE3372535D1/de not_active Expired
  • 1983-10-13 WO PCT/SE1983/000352 patent/WO1984001619A1/en active IP Right Grant
• 1986
  • 1986-03-24 US US06/843,320 patent/US4708062A/en not_active Expired - Fee Related

Patent Citations (4)

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