[go: up one dir, main page]

EP0384965A2 - Fin-stabilized subprojectile - Google Patents

Fin-stabilized subprojectile Download PDF

Info

Publication number
EP0384965A2
EP0384965A2 EP19890120959 EP89120959A EP0384965A2 EP 0384965 A2 EP0384965 A2 EP 0384965A2 EP 19890120959 EP19890120959 EP 19890120959 EP 89120959 A EP89120959 A EP 89120959A EP 0384965 A2 EP0384965 A2 EP 0384965A2
Authority
EP
European Patent Office
Prior art keywords
submunition
microreaction
submunition body
stabilized
engines
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.)
Withdrawn
Application number
EP19890120959
Other languages
German (de)
French (fr)
Other versions
EP0384965A3 (en
Inventor
Gerhard Dr. Glotz
Werner Grosswendt
Helmut Dr. Peller
Jens Dr. Seidensticker
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.)
Rheinmetall Industrie AG
Original Assignee
Rheinmetall GmbH
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 Rheinmetall GmbH filed Critical Rheinmetall GmbH
Publication of EP0384965A2 publication Critical patent/EP0384965A2/en
Publication of EP0384965A3 publication Critical patent/EP0384965A3/en
Withdrawn legal-status Critical Current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
    • F42B10/60—Steering arrangements
    • F42B10/66—Steering by varying intensity or direction of thrust
    • F42B10/661—Steering by varying intensity or direction of thrust using several transversally acting rocket motors, each motor containing an individual propellant charge, e.g. solid charge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41—WEAPONS
    • F41G—WEAPON SIGHTS; AIMING
    • F41G7/00—Direction control systems for self-propelled missiles
    • F41G7/20—Direction control systems for self-propelled missiles based on continuous observation of target position
    • F41G7/22—Homing guidance systems
    • F41G7/2233—Multimissile systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41—WEAPONS
    • F41G—WEAPON SIGHTS; AIMING
    • F41G7/00—Direction control systems for self-propelled missiles
    • F41G7/20—Direction control systems for self-propelled missiles based on continuous observation of target position
    • F41G7/22—Homing guidance systems
    • F41G7/2253—Passive homing systems, i.e. comprising a receiver and do not requiring an active illumination of the target
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F41—WEAPONS
    • F41G—WEAPON SIGHTS; AIMING
    • F41G7/00—Direction control systems for self-propelled missiles
    • F41G7/20—Direction control systems for self-propelled missiles based on continuous observation of target position
    • F41G7/22—Homing guidance systems
    • F41G7/2273—Homing guidance systems characterised by the type of waves
    • F41G7/2293—Homing guidance systems characterised by the type of waves using electromagnetic waves other than radio waves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B15/00—Self-propelled projectiles or missiles, e.g. rockets; Guided missiles
    • F42B15/01—Arrangements thereon for guidance or control

Definitions

  • the invention relates to a wing-stabilized submunition body with the features of the preamble of claim 1.
  • a known submunition of this type is usually accommodated in an artillery projectile which is fired in a twist-stabilized manner in indirect aiming.
  • the submunition body is ejected from the carrier shell in a manner known per se, then braked and swirled.
  • the stabilizing wings are then unfolded and an energy supply for a target detection device is activated, ground targets are detected by a corresponding search head when the submunition body is falling steadily, and the submunition body is optionally aligned with the detected target.
  • movable components are required for target acquisition and alignment of the submunition, such as e.g. a gimbal-mounted seeker head, a conventional gyroscope and standard actuators or rudder elements.
  • these moveable components undesirably reduce the firing strength and thus the reliability of such submunitions, moreover they require a high level of construction complexity and lead to undesirable cost developments.
  • the invention is therefore based on the object, while avoiding as many movable components as possible, to create a submunition body which is simple and inexpensive structure, as well as being characterized by high launch resistance and reliability.
  • a preferred embodiment of a wing-stabilized submunition 10 is shown.
  • a plurality of tail unit wings 12 projecting radially from the submunition body 10 and pivoting out of it.
  • the submunition body 10 contains a rigid sensor 14 as a seeker head, preferably an infrared sensor or a focal plain array.
  • a three-axis laser gyroscope 16 which is arranged directly behind the rigid sensor 14 in the submunition body 10, serves as the reference platform.
  • microreaction engines 18 are provided on the circumferential side and parallel to a longitudinal axis (not specified in any more detail), which function as individually ignitable small, once-burning, thrust-generating rocket motors.
  • Radial bores in the submunition body 10, which are not described in detail, are provided as nozzles for generating thrust by the combustion products generated in the microreaction engines 18.
  • the microreaction engines 18 are preferably arranged in front of the center of gravity of the submunition 10 directly behind the rigid sensor 14 and the laser gyro 16, so that the thrusts turn on the wing-stabilized submunition 10 and thus, together with the buoyancy of the submunition 10 and the tail unit 12, generate a transverse acceleration necessary for alignment to a dedicated target.
  • the individual microreaction engines 18 can be designed to be very small, so that up to 100 or more microreaction engines 18 can be accommodated in a suitable submunition body 10, thus enabling quasi-continuous projectile control.
  • an electronic part 20 a battery 22 serving for electrical supply and a warhead 24 as well as an ignition and safety device 26 associated therewith are shown in the illustration in the case of the submunition body 10 according to the invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Electromagnetism (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Gyroscopes (AREA)
  • Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)
  • Lasers (AREA)

Abstract

There is provided a fin-stabilised subprojectile (10) with a target acquisition device which, by the use of a rigid sensor (14) and a triaxial laser gyroscope (16), is characterised in comparison with known subprojectiles by a high firing stability and reliability, at the same time with a simple construction. <??>For control in a target area, there are microreaction propulsion units (18) which are arranged in the subprojectile (10) in front of its centre of gravity. <IMAGE>

Description

Die Erfindung betrifft einen flügelstabilisierten Sub­munitionskörper mit den Merkmalen des Oberbegriffes des Patentanspruches 1.The invention relates to a wing-stabilized submunition body with the features of the preamble of claim 1.

Ein bekannter derartiger Submunitionskörper wird üblicherweise in einem Artilleriegeschoß untergebracht, das in indirektem Richten drallstabilisiert verschossen wird.
Bei Erreichen des vorgegebenen Zielgebietes wird der Submuniti­onskörper in an sich bekannter Weise aus der Trägerhülle ausge­stoßen, danach abgebremst und entdrallt.
Nach anschließendem Ausklappen der Stabilisierungsflügel und Ak­tivierung einer Energieversorgung für eine Zielerfassungsvor­richtung werden durch einen entsprechenden Suchkopf bei stabi­lem Sinkflug des Submunitionskörpers Bodenziele dedektiert und der Submunitionskörper gegebenenfalls auf das erfaßte Ziel aus­gerichtet.A known submunition of this type is usually accommodated in an artillery projectile which is fired in a twist-stabilized manner in indirect aiming.
When the predetermined target area is reached, the submunition body is ejected from the carrier shell in a manner known per se, then braked and swirled.
After the stabilizing wings are then unfolded and an energy supply for a target detection device is activated, ground targets are detected by a corresponding search head when the submunition body is falling steadily, and the submunition body is optionally aligned with the detected target.

Bei bisher bekannt gewordenen gattungsgemäßen Submunitionskör­pern sind zur Zielerfassung und zur Ausrichtung des Submunitionskörpers bewegliche Komponenten erforderlich, wie z.B. ein kardanisch gelagerter Suchkopf, ein herkömmlicher Kreisel sowie übliche Stellantriebe oder Ruderelemente. Diese beweglichen Komponenten setzen jedoch die Abschußfestigkeit und damit die Zuverlässigkeit derartiger Submunitionskörper in uner­wünschter Weise herab.Darüber hinaus erfordern sie eine hohe Komplexität der Konstruktion und führen zu unerwünschten Koste­nentwicklungen.In the case of generic submunitions known so far, movable components are required for target acquisition and alignment of the submunition, such as e.g. a gimbal-mounted seeker head, a conventional gyroscope and standard actuators or rudder elements. However, these moveable components undesirably reduce the firing strength and thus the reliability of such submunitions, moreover they require a high level of construction complexity and lead to undesirable cost developments.

Der Erfindung liegt daher die Aufgabe zugrunde, unter Vermei­dung möglichst vieler beweglicher Komponenten einen Submuni­tionskörper zu schaffen, der sich durch einen einfachen und preisgünstigen Aufbau sowie durch eine hohe Abschußfestigkeit und Zuverlässigkeit auszeichnet.The invention is therefore based on the object, while avoiding as many movable components as possible, to create a submunition body which is simple and inexpensive structure, as well as being characterized by high launch resistance and reliability.

Diese Aufgabe wird gelöst durch einen erfindungsgemäßen Submunitionskörper mit den Merkmalen des kennzeichnenden Teiles des Patentanspruches 1.This object is achieved by a submunition body according to the invention with the features of the characterizing part of patent claim 1.

Vorteilhafte Ausgestaltungen der Erfindung gehen aus den Unteransprüchen hervor.Advantageous embodiments of the invention emerge from the subclaims.

Im folgenden wird die Erfindung anhand eines Ausführungsbeispieles unter Zuhilfenahme einer Zeichnung ausführlich erläutert und beschrieben.In the following, the invention is explained and described in detail using an exemplary embodiment with the aid of a drawing.

In der Zeichnung ist ein bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen flügelstabilisierten Submunitionskörpers 10 dargestellt. Als Leitwerk dienen mehrere radial vom Submunitionskörper 10 abstehende, aus diesem herausschwenkbare Leitwerkflügel 12. In seinem vorderen Teil enthält der Submunitionskörper 10 einen starren Sensor 14 als Suchkopf, vorzugsweise ein Infrarotsensor oder ein Focal plain array. Als Referenzplattform dient ein dreiachsiger Laserkreisel 16, der direkt hinter dem starren Sensor 14 im Submunitionskörper 10 angeordnet ist.In the drawing, a preferred embodiment of a wing-stabilized submunition 10 according to the invention is shown. Serving as the tail unit are a plurality of tail unit wings 12 projecting radially from the submunition body 10 and pivoting out of it. In its front part, the submunition body 10 contains a rigid sensor 14 as a seeker head, preferably an infrared sensor or a focal plain array. A three-axis laser gyroscope 16, which is arranged directly behind the rigid sensor 14 in the submunition body 10, serves as the reference platform.

Im Submunitionskörper sind hinter dem Laserkreisel 16 umfangsseitig und parallel zu einer nicht näher bezeichneten Längsachse angeordnete Mikroreaktionstriebwerke 18 vorgesehen, die individuell anzündbar als kleine einmalig abbrennende, Schub erzeugende Raketenmotoren funktionieren. Als Düsen zur Schuberzeugung durch die in den Mikroreaktionstriebwerken 18 entstehenden Verbrennungsprodukte sind nicht näher bezeichnete radiale Bohrungen im Submunitionskörper 10 vorgesehen. Die Mikroreaktionstriebwerke 18 sind vorzugsweise vor dem Schwerpunkt des Submunitionskörpers 10 direkt hinter dem starren Sensor 14 und dem Laserkreisel 16 angeordnet, so daß die Schübe den flügelstabilisierten Submunitionskörper 10 anstellen und so zusammen mit dem Auftrieb des Submunitionskörpers 10 und der Leitwerkflügel 12 eine für die Ausrichtung auf ein dedektiertes Ziel notwendige Querbeschleunigung erzeugen. Die einzelnen Mikroreaktionstriebwerke 18 können sehr kleinbauend ausgelegt werden, so daß in einem geeigneten Submunitionskörper 10 bis zu 100 und mehr Mikroreaktionstriebwerke 18 untergebracht werden können und somit eine quasi kontinuierliche Geschoßsteuerung ermöglicht wird.In the submunition body, behind the laser gyroscope 16, microreaction engines 18 are provided on the circumferential side and parallel to a longitudinal axis (not specified in any more detail), which function as individually ignitable small, once-burning, thrust-generating rocket motors. Radial bores in the submunition body 10, which are not described in detail, are provided as nozzles for generating thrust by the combustion products generated in the microreaction engines 18. The microreaction engines 18 are preferably arranged in front of the center of gravity of the submunition 10 directly behind the rigid sensor 14 and the laser gyro 16, so that the thrusts turn on the wing-stabilized submunition 10 and thus, together with the buoyancy of the submunition 10 and the tail unit 12, generate a transverse acceleration necessary for alignment to a dedicated target. The individual microreaction engines 18 can be designed to be very small, so that up to 100 or more microreaction engines 18 can be accommodated in a suitable submunition body 10, thus enabling quasi-continuous projectile control.

Der Vollständigkeit halber sind bei dem erfindungsgemäßen Submunitionskörper 10 in der Abbildung noch ein Elektronikteil 20, eine zur elektrischen Versorgung dienende Batterie 22 und ein Gefechtskopf 24 sowie eine diesem zugeordnete Zünd- und Sicherungseinrichtung 26 dargestellt.For the sake of completeness, an electronic part 20, a battery 22 serving for electrical supply and a warhead 24 as well as an ignition and safety device 26 associated therewith are shown in the illustration in the case of the submunition body 10 according to the invention.

Claims (4)

Flügelstabilisierter Submunitionskörper mit einer Zielerfassungsvorrichtung, der in einem Zielgebiet aus einem drallstabilisierten Artillerie-­Trägergeschoß ausstoßbar ist, dadurch ge­kennzeichnet, daß der Submunitionskörper (10) einen starren Sensor (14) als Suchkopf und einen dreiachsigen Laserkreisel (16) als Referenzplattform enthält, und daß als Steuersystem eine Vielzahl von Mikro­reaktionstriebwerken (18), die im Submunitionskörper (10) umfangsseitig angeordnet sind, verwendet werden.Wing-stabilized submunition body with a target detection device which can be ejected from a spin-stabilized artillery carrier projectile in a target area, characterized in that the submunition body (10) contains a rigid sensor (14) as a seeker head and a three-axis laser gyroscope (16) as a reference platform, and that as Control system a variety of microreaction engines (18), which are arranged circumferentially in the submunition (10), are used. 2. Submunitionskörper nach Anspruch 1, dadurch ge­kennzeichnet, daß die Mikroreaktionstriebwerke (18) vor dem Schwerpunkt des Submunitionskörpers (10) angeordnet sind.2. Submunition body according to claim 1, characterized in that the microreaction engines (18) are arranged in front of the center of gravity of the submunition body (10). 3. Submunitionskörper nach Anspruch 2, dadurch ge­kennzeichnet, daß er eine Auswerte- und Steuerelektronik enthält zum Auswerten der vom starren Sensor (14) aufgenommenen Zielcharakteristika und zum gezielten Auslösen der Mikroreaktionstriebwerke.3. Submunition body according to claim 2, characterized in that it contains evaluation and control electronics for evaluating the target characteristics recorded by the rigid sensor (14) and for specifically triggering the microreaction engines. 4. Submunitionskörper nach Anspruch 3, dadurch gekennzeichnet, daß der starre Sensor (14) ein Infrarot-Sensor ist.4. Submunition body according to claim 3, characterized in that the rigid sensor (14) is an infrared sensor.
EP19890120959 1989-03-01 1989-11-11 Fin-stabilized subprojectile Withdrawn EP0384965A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3906372 1989-03-01
DE3906372A DE3906372A1 (en) 1989-03-01 1989-03-01 WING-STABILIZED SUBMUNITION BODY

Publications (2)

Publication Number Publication Date
EP0384965A2 true EP0384965A2 (en) 1990-09-05
EP0384965A3 EP0384965A3 (en) 1992-08-12

Family

ID=6375175

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890120959 Withdrawn EP0384965A3 (en) 1989-03-01 1989-11-11 Fin-stabilized subprojectile

Country Status (4)

Country Link
US (1) US5037040A (en)
EP (1) EP0384965A3 (en)
CA (1) CA2011046A1 (en)
DE (1) DE3906372A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110077588A (en) * 2019-04-22 2019-08-02 大连理工大学 It is a kind of can the sea, land and air latent four of VTOL dwell aircraft

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5261629A (en) * 1989-04-08 1993-11-16 Rheinmetall Gmbh Fin stabilized projectile
DE29512894U1 (en) * 1995-08-10 1995-10-26 Mafo Systemtechnik Dr.-Ing. A. Zacharias GmbH & Co. KG, 83317 Teisendorf weapon
US6502785B1 (en) * 1999-11-17 2003-01-07 Lockheed Martin Corporation Three axis flap control system
US20070089628A1 (en) * 2005-10-20 2007-04-26 Elder Steven M Firearm ammunition having improved flight and impact characteristics
SE534614C2 (en) * 2010-02-25 2011-10-25 Bae Systems Bofors Ab Garnet provided with folding wings and control device
US9464876B2 (en) * 2014-05-30 2016-10-11 General Dynamics Ordnance and Tacital Systems, Inc. Trajectory modification of a spinning projectile by controlling the roll orientation of a decoupled portion of the projectile that has actuated aerodynamic surfaces

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3282540A (en) * 1964-05-05 1966-11-01 Henry S Lipinski Gun launched terminal guided projectile
EP0028966A1 (en) * 1979-11-09 1981-05-20 Thomson-Brandt Armements Method of piloting and guiding missiles in terminal flight
EP0081421A1 (en) * 1981-12-09 1983-06-15 Thomson-Brandt Armements Terminal guidance method and guided missile using it
DE3337873A1 (en) * 1982-10-18 1984-04-19 Raytheon Co., 02173 Lexington, Mass. BULLET FOR GRENADE LAUNCHER SYSTEMS
US4598884A (en) * 1984-11-28 1986-07-08 General Dynamics Pomona Division Infrared target sensor and system

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3304434A (en) * 1965-06-01 1967-02-14 Bunker Ramo Position control system employing pulse producing means indicative of magnitude and direction of movement
US4533094A (en) * 1982-10-18 1985-08-06 Raytheon Company Mortar system with improved round

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3282540A (en) * 1964-05-05 1966-11-01 Henry S Lipinski Gun launched terminal guided projectile
EP0028966A1 (en) * 1979-11-09 1981-05-20 Thomson-Brandt Armements Method of piloting and guiding missiles in terminal flight
EP0081421A1 (en) * 1981-12-09 1983-06-15 Thomson-Brandt Armements Terminal guidance method and guided missile using it
DE3337873A1 (en) * 1982-10-18 1984-04-19 Raytheon Co., 02173 Lexington, Mass. BULLET FOR GRENADE LAUNCHER SYSTEMS
US4598884A (en) * 1984-11-28 1986-07-08 General Dynamics Pomona Division Infrared target sensor and system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110077588A (en) * 2019-04-22 2019-08-02 大连理工大学 It is a kind of can the sea, land and air latent four of VTOL dwell aircraft
WO2020215304A1 (en) * 2019-04-22 2020-10-29 大连理工大学 Sea-land-air-underwater adapted vehicle capable of vertical take-off and landing
CN110077588B (en) * 2019-04-22 2022-05-20 大连理工大学 Sea, land and air submerged four-purpose aircraft capable of taking off and landing vertically
US11433999B2 (en) 2019-04-22 2022-09-06 Dalian University Of Technology Vehicle capable of taking off and landing vertically and operating in water, land, air and submarine environments

Also Published As

Publication number Publication date
CA2011046A1 (en) 1990-09-01
DE3906372C2 (en) 1991-06-27
DE3906372A1 (en) 1990-09-13
EP0384965A3 (en) 1992-08-12
US5037040A (en) 1991-08-06

Similar Documents

Publication Publication Date Title
DE2833079C1 (en) Steering floor
DE2904749C2 (en) Missile in the manner of a drone
DE19740888C2 (en) Method for autonomously steering a spin-stabilized artillery projectile and autonomously guided artillery projectile for carrying out the method
EP1399706B1 (en) Artillery projectile comprising an interchangeable payload
EP2071270A2 (en) Tilted igniter
EP1035401B1 (en) Launching device for firing multiple charges
DE69129815T2 (en) Penetrator ammunition for targets with high mechanical resistance
WO2009006981A1 (en) Method and launching apparatus for protection of an object against a threat, in particular a missile, as well as munition
EP1762815B1 (en) Munition with seeking fuze
EP0384965A2 (en) Fin-stabilized subprojectile
EP2405233B1 (en) Method for guiding a military missile
DE2518593A1 (en) BULLET
EP0249678B2 (en) Ammunition, especially for fighting targets provided with a reactive armour
DE4401315B4 (en) Device for trajectory correction
DE3643197A1 (en) Aiming device for a tube weapon (weapon with a barrel)
DE2209445C3 (en) Warhead
DE102019104866A1 (en) Drone and anti-targeting methods
DE102004002471B4 (en) Device and method for delivering a drive energy
DE3119185C2 (en) &#34;Steerable Missile&#34;
EP0187900B1 (en) Pilotless aircraft for fighting ground targets
DE19540252C2 (en) Procedure for guiding submunitions into a target and carrier therefor
DE102019109360A1 (en) Invention system for defense against RAM targets and / or UAVs as well as methods for defense against RAM targets and / or UAVs
EP4459221A1 (en) Hover ammunition for firing through existing devices and systems
DE3722038A1 (en) Drone with a warhead
WO2009046798A1 (en) Method for transferring sonar buoys to a target area and missile for carrying out said method

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

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB IT SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB IT SE

RAP3 Party data changed (applicant data changed or rights of an application transferred)

Owner name: RHEINMETALL GMBH

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

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19930213