EP0076990A2 - Ailettes stabilisatrices pour projectile - Google Patents

Ailettes stabilisatrices pour projectile Download PDF

Info

Publication number
EP0076990A2
EP0076990A2 EP82109120A EP82109120A EP0076990A2 EP 0076990 A2 EP0076990 A2 EP 0076990A2 EP 82109120 A EP82109120 A EP 82109120A EP 82109120 A EP82109120 A EP 82109120A EP 0076990 A2 EP0076990 A2 EP 0076990A2
Authority
EP
European Patent Office
Prior art keywords
fins
projectile
space
barrel
assembly
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.)
Granted
Application number
EP82109120A
Other languages
German (de)
English (en)
Other versions
EP0076990A3 (en
EP0076990B1 (fr
Inventor
Jan-Erik Sandberg
Torbjörn Pramskog
Bengt Larsson
Börje Johansson
Sven Andersson
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.)
AFFAERSVERKET FFV
Original Assignee
Foerenade Fabriksverken AB
Affarsverket FFV
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 Foerenade Fabriksverken AB, Affarsverket FFV filed Critical Foerenade Fabriksverken AB
Publication of EP0076990A2 publication Critical patent/EP0076990A2/fr
Publication of EP0076990A3 publication Critical patent/EP0076990A3/en
Application granted granted Critical
Publication of EP0076990B1 publication Critical patent/EP0076990B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B10/00—Means for influencing, e.g. improving, the aerodynamic properties of projectiles or missiles; Arrangements on projectiles or missiles for stabilising, steering, range-reducing, range-increasing or fall-retarding
    • F42B10/02—Stabilising arrangements
    • F42B10/14—Stabilising arrangements using fins spread or deployed after launch, e.g. after leaving the barrel
    • F42B10/20—Stabilising arrangements using fins spread or deployed after launch, e.g. after leaving the barrel deployed by combustion gas pressure, or by pneumatic or hydraulic forces

Definitions

  • the present invention relates to a stabilizing fin assembly for a rotating or non-rotating projectile designed to be discharged from a rifled or smooth barrel by means of propellant charge gases, having a plurality of elongated fins, rotatably mounted at one end, which are arranged so that during the passage of the projectile through the barrel they are in the retracted position, in which the fins are placed on edge extending mutually in parallel and mainly in the lengthwise direction of the projectile.
  • the fins are normally extended by means of spring force or with the aid of lifting surfaces arranged on the fins which are affected by the wind velocity.
  • the method is also known of utilising the gas pressure produced by the propellant charge for extension purposes.
  • the pressure acts on a piston or the like which presses the fins outwards.
  • the present invention is based on the new concept that it is possible to extend fins placed on edge without the use of either springs, pistons or lifting surfaces.
  • the space between the fins and/or a further space which is located underneath one edge on the fins which faces the projectile axis is during the passage of the projectile through the barrel at least partially open at the rear, permitting access by the propellant charge gases to the said space or the said further space respectively, whereby the passage of the projectile past the barrel muzzle results in the propellant charge gases in the said space or respective said further space rushing outwards to the atmosphere surrounding the barrel and thereby jerking with them the fins into the extended position, partly because of the assisting frictional force which is generated when the propellant charge gases pass along the guide surfaces of the fins and partially - in the event of the said further space being present - because of the pressure exercised by the gases in the further space against the said edge of the fins.
  • Figure 1 shows a projectile 2 inserted in a barrel 1 which via a conventional girdle 3 is attached to a cartridge case 4 containing a propellant charge 5.
  • the barrel 1 can be either smooth or rifled and forms part of a weapon which is not shown, e.g. a mortar.
  • the projectile 2 has a rear section 6 which extends into the sleeve 4 up to the propellant charge 5. At its rear end the rear section 6 is provided with six fin attachments 7 (see Figures 2, 7 and 8), in each of which an extended fin 8 which is located on edge against the rear section 6 is rotatably mounted around a pivot pin 9 which is shown schematically.
  • the pivot pin 9 are provided with friction-reducing devices in the form of teflon washers 10 so as to increase the swivel capacity of the fins. It is also feasible to employ other types of friction-reducing devices. For drafting purposes the teflon washers 10 are illustrated only in Figure 7 and then only in one of the fin attachments 7.
  • the fins 8 taper to the rear, so that a wedge-shaped gap 11 is formed between the rear section 6 and the edge 12 of the fins facing the projectile axis.
  • the space 13 between the fins 8 is open at the back towards the propellant charge 5, as can be best seen from Figure 4.
  • propellant charge gases are produced which attempt to discharge the projectile 2.
  • the propellant charge gases fill on the one hand the space 13 between the fins and secondly the wedge-shaped gap 11.
  • the propellant charge gases overcome the resistance to release of the girdle 3, the projectile moves out of the barrel 1 (on the left in Figure 1).
  • the girdle 3 also performs a sealing function in that it permits only a negligible leakage of propellant charge gases to the atmosphere surrounding the barrel.
  • the girdle 3 passes the muzzle of the barrel (shown schematically at 1a), the propellant charge gases however rush out of the barrel.
  • the wedge-shaped space 11 is filled by propellant charge gases, and extending force is also imposed on the fins 8, because the gases in space 11 exert a direct pressure against the edges 12 of the fins.
  • the fins 8 have their centre of gravity G closer to the projectile axis than the centre of rotation 9 of the fins, so that the acceleration forces on the projectile during its discharge bring about a moment which attempts to hold in the fins 8 during passage through the barrel. This location of the centre of gravity is particularly advisable for rotating projectiles.
  • the fins 8 can be skewed at a pre-determined twist angle v so as to maintain or bring about a desired degree of rotation.
  • Figures 7 and 8 show how the fins 8 are mounted in oblique grooves 14 in the fin attachment 7.
  • the rear section 6 has a supporting heel 15 on the skewed side of each fin 8 which prevents the fin being deformed as a result of the accelerational forces to which it is subjected during its passage through the barrel.
  • Such supporting heels can possibly be arranged on both sides of the fins.
  • this support function can be provided by grooves in the rear section 6.
  • FIG. 2 illustrates a second embodiment of the invention which in principle differs from the embodiment shown in Figure 1 only in that the rear section of the projectile 2 is replaced by a guidance mechanism tube 16, shown partially in section, which tapers away forwards and which is open at the rear and which at the front by means for example of a screw connection is fastened to a centrally arranged heel 17 at the rear end of the projectile 2.
  • the interior of tube 16 by this means forms a chamber 18 which is open rearwards towards the propellant charge 5.
  • the tube 16 is provided with six longitudinal slots 19 through which the fins 8 can be partially introduced, as indicated by the dashed edge lines 12. Here the slots 19 provide support for the fins during the passage of the projectile through the barrel.
  • the chamber 18 and the space 13 between the fins 8 is filled by the propellant charge gases from the propellant charge 5. This ensures firstly that a larger quantity of gas passes along the guidance surfaces of the fins 8 as the gases rush out to the surrounding atmosphere, and secondly that the gases enclosed in the chamber 18 during their outward rushing motion bring about a pressure which is orientated directly towards the edge 12 of the fins 8 which increases the force which extends the fins.
  • the chamber 18 and the space 13 between the fins 8 are both open at the rear. However it is possible to allow the space 13 to be sealed towards the rear so that the propellant charge gases during their passage through the barrel can flow only into the chamber 18.
  • the slots 19 can be so dimensioned that there is no alternative desired degree of gas passage permissible from the chamber 18 to the space 13 via the slots 19 even when the fins 8 are introduced into these.
  • the chamber 28 can be sealed at the rear whilst the space 13 is open at the rear.
  • the slots 19 are so dimensioned that they permit a flow of gas from the space 13 to the chamber 18 even when the fins 8 are introduced into the slots 19.
  • the embodiment illustrated in Figure 3 differs from the embodiment shown in Figure 2 in that the conically-tapered, slotted guidance mechanism tube 16 is replaced by a guidance mechanism tube 20 of uniform thickness, the interior of which forms a cylindrical chamber 18a and which instead of slots has two apertures 21 all the way through, these being circular in the embodiment illustrated, located in the centre of each fin 8.
  • the apertures 21 have roughly the same dimensions as the thickness of the fins 8.
  • the rear end of the tube 20 in the embodiment illustrated is sealed by a wall 22 which has a central circular aperture 23 all the way through which provides a direct connection between the propellant charge 5 and the interior of the guidance mechanism tube 20.
  • the propellant charge gases in the tube 20 bring about a concentrated compressive force on the edge 12 on the fins 8 which faces the projectile axis, so that a particularly high force is obtained which tends to extend the fins.
  • the rear section 6 is, possibly via a strap or girdle which is not shown, and preferably exhibiting leakage, fastened into a cartridge case 4 with propellant charge 5.
  • the rear section 6 and the tube 25 have a diameter which is somewhat smaller than the barrel 1, so that a ring-shaped gap 26 is formed between them.
  • the tube 24 is provided with a strap or girdle 27.
  • the fixed pivot of the fins is located at the rear end of the fins, as viewed in the retracted position of the fins.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Toys (AREA)
  • Saccharide Compounds (AREA)
EP82109120A 1981-10-08 1982-10-02 Ailettes stabilisatrices pour projectile Expired EP0076990B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8105952A SE428058B (sv) 1981-10-08 1981-10-08 Styrverk for projektil
SE8105952 1981-10-08

Publications (3)

Publication Number Publication Date
EP0076990A2 true EP0076990A2 (fr) 1983-04-20
EP0076990A3 EP0076990A3 (en) 1983-05-18
EP0076990B1 EP0076990B1 (fr) 1986-02-19

Family

ID=20344732

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82109120A Expired EP0076990B1 (fr) 1981-10-08 1982-10-02 Ailettes stabilisatrices pour projectile

Country Status (5)

Country Link
EP (1) EP0076990B1 (fr)
DE (1) DE3269205D1 (fr)
FI (1) FI823432L (fr)
NO (1) NO149942C (fr)
SE (1) SE428058B (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0171473A1 (fr) * 1984-06-04 1986-02-19 The State Of Israel Ministry Of Defence Israel Military Industries Système de stabilisation pour projectile
FR2769287A1 (fr) 1997-10-08 1999-04-09 Lacroix Soc E Dispositif de freinage de la chute d'une charge
WO2002006760A1 (fr) * 2000-07-03 2002-01-24 Bofors Defence Ab Munition a derive stabilisee
WO2002006759A1 (fr) * 2000-07-03 2002-01-24 Bofors Defence Ab Procede et arrangement destines a des missiles d'artillerie

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE444612B (sv) * 1984-12-13 1986-04-21 Ffv Affersverket Styrverk for utfellning av fenor hos projektil

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1405276A (en) * 1918-07-10 1922-01-31 John T Careaga Expanding projectile
US3589645A (en) * 1969-07-15 1971-06-29 Forsvarets Fabriksverk Foldout fins forming stable flight for a nonspinning projectile
DE2721536A1 (de) * 1977-05-13 1978-11-16 Brunsch Kurt Projektil mit leitflaechen

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1405276A (en) * 1918-07-10 1922-01-31 John T Careaga Expanding projectile
US3589645A (en) * 1969-07-15 1971-06-29 Forsvarets Fabriksverk Foldout fins forming stable flight for a nonspinning projectile
DE2721536A1 (de) * 1977-05-13 1978-11-16 Brunsch Kurt Projektil mit leitflaechen

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0171473A1 (fr) * 1984-06-04 1986-02-19 The State Of Israel Ministry Of Defence Israel Military Industries Système de stabilisation pour projectile
US4641802A (en) * 1984-06-04 1987-02-10 The State Of Israel, Ministry Of Defence, Israel Military Industries Projectile stabilization system
FR2769287A1 (fr) 1997-10-08 1999-04-09 Lacroix Soc E Dispositif de freinage de la chute d'une charge
WO2002006760A1 (fr) * 2000-07-03 2002-01-24 Bofors Defence Ab Munition a derive stabilisee
WO2002006759A1 (fr) * 2000-07-03 2002-01-24 Bofors Defence Ab Procede et arrangement destines a des missiles d'artillerie
US6886775B2 (en) 2000-07-03 2005-05-03 Bofors Defence Ab Fin-stabilized shell
US7226016B2 (en) 2000-07-03 2007-06-05 Bae Systems Bofors Ab Method and arrangement for low or non-rotating artillery shells

Also Published As

Publication number Publication date
EP0076990A3 (en) 1983-05-18
DE3269205D1 (en) 1986-03-27
NO149942B (no) 1984-04-09
SE8105952L (sv) 1983-04-09
FI823432A0 (fi) 1982-10-08
FI823432L (fi) 1983-04-09
NO823362L (no) 1983-04-11
SE428058B (sv) 1983-05-30
NO149942C (no) 1984-07-18
EP0076990B1 (fr) 1986-02-19

Similar Documents

Publication Publication Date Title
US3726231A (en) Sabot bullet
GB2110799A (en) An armour piercing projectile
GB2234331A (en) Hollow charge liner.
US4075946A (en) Armor piercing projectile
US5725179A (en) Expansion wave spin inducing generator
EP1038152B1 (fr) Bombe aerienne munie d'une enveloppe
EP0076990A2 (fr) Ailettes stabilisatrices pour projectile
US6389977B1 (en) Shrouded aerial bomb
US6408762B1 (en) Clamp assembly for shrouded aerial bomb
US4967668A (en) Puller sabot for long rod projectiles
EP0171473B1 (fr) Système de stabilisation pour projectile
US6123289A (en) Training projectile
EP0120215B1 (fr) Munition pour mortier
US4886223A (en) Projectile with spin chambers
EP0038310B1 (fr) Projectile balistique à empennage déployable
US3662686A (en) Rod and sabot assembly
GB2113362A (en) Hollow charges
US5328130A (en) Stabilizer for a cannon projectile
US7690305B2 (en) Increment charge for fin-stabilized mortar projectile
US4519316A (en) Ammunition, preferably for machine cannons, including a projectile equipped with a tracer, with the lethal range of the projectile being limited if the target is missed
EP1367358B1 (fr) Bombe aérienne munie d'une enveloppe
JPS61502485A (ja) 砲弾用の管状弾殻
EP0506150B1 (fr) Dispositif de lancement pour une grenade de mortier
US5710391A (en) Recoil reducer wad for ammunition
US3845922A (en) Sabot projectile

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

17P Request for examination filed

Effective date: 19821018

AK Designated contracting states

Designated state(s): CH DE FR GB LI

AK Designated contracting states

Designated state(s): CH DE FR GB LI

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: AFFAERSVERKET FFV

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): CH DE FR GB LI

REF Corresponds to:

Ref document number: 3269205

Country of ref document: DE

Date of ref document: 19860327

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19871031

Ref country code: CH

Effective date: 19871031

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19880630

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19880701

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19881121