EP0290773B1 - Procédé de fabrication par meulage de pièces profilées et aube de turbine ainsi fabriquée - Google Patents

Procédé de fabrication par meulage de pièces profilées et aube de turbine ainsi fabriquée Download PDF

Info

Publication number
EP0290773B1
EP0290773B1 EP88105239A EP88105239A EP0290773B1 EP 0290773 B1 EP0290773 B1 EP 0290773B1 EP 88105239 A EP88105239 A EP 88105239A EP 88105239 A EP88105239 A EP 88105239A EP 0290773 B1 EP0290773 B1 EP 0290773B1
Authority
EP
European Patent Office
Prior art keywords
grinding
blade
per unit
time
blank
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
EP88105239A
Other languages
German (de)
English (en)
Other versions
EP0290773A1 (fr
Inventor
Ulrich Kühne
Klaus Meyer
Karlheinz Heine
Klaus Rüschmann
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.)
Siemens AG
Original Assignee
Siemens AG
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 Siemens AG filed Critical Siemens AG
Priority to AT88105239T priority Critical patent/ATE63709T1/de
Publication of EP0290773A1 publication Critical patent/EP0290773A1/fr
Application granted granted Critical
Publication of EP0290773B1 publication Critical patent/EP0290773B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/14—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding turbine blades, propeller blades or the like
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2200/00—Mathematical features
    • F05B2200/30—Mathematical features miscellaneous
    • F05B2200/31—Mathematical features miscellaneous odd
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49316—Impeller making

Definitions

  • the present invention relates to a method for producing a profile part from a blank, in particular for producing a turbomachine blade and an associated intermediate product.
  • the object of the present invention is to create a method which enables the most economical production of profile parts, the cross-sectional profile of which, at least in some areas, differs considerably from the cross-sectional profile of the associated blank.
  • the invention relates to a turbomachine blade manufactured according to this method, and to a typical associated intermediate product.
  • a typical application example is the production of a turbomachine blade.
  • the method according to the invention also occurs a very specific intermediate product, which is explained with its individual embodiments in claims 5 to 9.
  • the process is particularly suitable for the production of small turbomachine blades.
  • the The feed is therefore controlled or regulated in such a way that the machining volume per unit of time follows a predefinable function, preferably remains approximately constant. This means that the rotation and translation are slowed down if a lot of material has to be removed from the point just processed.
  • the entire constellation of the blank, the profile to be produced and the machining state achieved can be taken into account when determining an optimal function which the machining volume per unit time is to follow.
  • Decisive for the heating of the workpiece during grinding is the heat dissipation from the grinding point. Part of the heated material is removed immediately afterwards, for example, so that this heat input is not critical.
  • the dimensions of the workpiece, its heat capacity and thermal conductivity must be taken into account (in short: heat dissipation in the vicinity of the grinding point). It generally applies that the cutting volume per unit of time should be smaller the worse the heat dissipation at the grinding point. E.g. in very thin areas of the workpiece, the machining volume per unit of time must u. U. be reduced.
  • a method with the characterizing features of claim 5 is particularly economical. By grinding all non-concave contours of the blade in just one clamping, many work steps of the previously known machining steps can be saved. Manufacturing with very low tolerances is possible because of inaccuracies due to changing clamping of the workpiece. Considerable time savings in production can also be achieved since the intermediate storage of entire batches, from partially completed blades to the conversion of a machine to new machining tools, is practically completely eliminated.
  • the intermediate product has a total length f which is greater than the length a of the blade to be manufactured.
  • the blade itself consists of a blade root 2 with webs 2.1 and 2.2 grooves; all foot shapes known in the prior art can be used.
  • the blade has a head which has a parallelogram-shaped cross section and forms a closed shroud together with other blade heads during later installation.
  • the actual blade contour has a rounded inflow side 6, a pointed outflow side 7 and a convex suction side 4.
  • the later concave pressure side 5 is not yet finished in the intermediate product shown, but only ground flat.
  • the contour of the blade root 2 is lengthened by the length b, and the contour of the blade head 3 is lengthened by the length c.
  • a cutting device can later be attached in a defined manner. Further points the intermediate product has two remnants 8, 9 at the two ends, which do not necessarily have the same lengths c and e. These remnants serve to firmly clamp the blank or intermediate product during the entire grinding process.
  • the present invention enables e.g. an economical, precise manufacture of blades for turbomachinery, whereby a very fast production run is possible by saving many different work steps.
  • the production planning is simplified because intermediate storage is no longer necessary; the manufacturing time for an entire set of blades can be significantly reduced.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Claims (9)

1. Procédé de fabrication d'une pièce profilée (1) à partir d'une ébauche, le profil de la section transversale de la pièce à fabriquer se distinguant, au moins dans certaines parties, quantitativement et qualitativement du profil de la section transversale de l'ébauche, de sorte que les différences de matière à enlever entre le profil initial et le profil final sont différentes, ayant les caractéristiques suivantes:
a) On préforme et on finit à la meule la pièce à fabriquer bloquée une fois pour toutes par au moins une meule qui est dressée de préférence en permanence.
b) Lors du préformage, on donne à l'ébauche, par translation et par rotation par rapport à la meule ou aux meules éventuellement profilées, à peu près le profil souhaité, les profondeurs locales de meulage étant choisies à peu près égales aux différences de matière à enlever.
c) Le finissage à la meule est effectué entièrement ou par section après le préformage et sert à polir les surfaces et à donner au profil final les dimensions exactes.
2. Procédé suivant la revendication 1, caractérisé en ce que, lors du préformage, on règle ou on commande les avances des rotations nécessaires à l'obtention du profil souhaité et les translations par rapport à la meule, en fonction des différences de matière à enlever, de manière que le volume de matière enlevée par unité de temps suive une fonction prescrite, éventuellement variable en fonction de l'emplacement et/ou du temps, en restant notamment constant au moins dans certaines parties.
3. Procédé suivant la revendication 1 ou 2, caractérisé en ce que, lors du préformage, à une phase opératoire avec un grand volume de matière enlevée par unité de temps, à peu près jusqu'au contour à obtenir définitivement, fait suite au moins une phase opératoire avec un volume de matière enlevée par unité de temps qui est plus faible.
4. Procédé suivant la revendication 1 ou 2, caractérisé en ce que, lors du préformage, on commande ou on règle le volume de matière enlevée par unité de temps, en fonction de l'évacuation de la chaleur de la pièce dans la partie environnante du point de meulage.
5. Procédé suivant l'une des revendications précédentes de fabrication d'un produit intermédiaire (1) pour une aube de turbomachine, remarquable par les caractéristiques suivantes:
a) on bloque, par ses deux extrémités, un bloc métallique oblong ayant, de préférence, une section transversale sensiblement rectangulaire ou en forme de parallélogramme, dont la longueur (f) est plus grande de 5 à 30% et, de préférence, de 20% environ que la longueur (a) de l'aube à fabriquer,
b) par rotation autour de l'axe longitudinal du bloc métallique et par translation par rapport à une meule tournant rapidement, on meule les contours du côté d'aspiration (4), du pied d'aube (2) et de la tête d'aube (3) dans le bloc métallique, des pièces restantes (7, 8) dépassant, à la fois du côté du pied et du côté de la tête, subsistant en ayant la section transversale d'origine du bloc en acier,
c) les dimensions en longueur du contour du pied et du contour de la tête dépassent légèrement les dimensions à obtenir réellement, de préférence d'au moins la largeur de la voie d'une scie ou d'un dispositif de coupe.
6. Procédé suivant la revendication 5, caractérisé en ce qu'en faisant basculer le bloc métallique d'un angle déterminé, on obtient également un amincissement radial de l'aube, sans modifier le blocage.
7. Procédé suivant la revendication 5 ou 6, caractérisé en ce que le dépassement (d, e) des pièces résiduelles (8, 9) du côté du pied et du côté de la tête est d'au moins 2 mm.
8. Procédé suivant la revendication 5, 6 ou 7, caractérisé en ce que l'excès de dimension (b, c) des contours de pied et de la tête est compris entre 0,5 et 4 mm et, de préférence, est de 3 mm environ.
9. procédé suivant la revendication 5, 6, 7 ou 8, caractérisé en ce que le côté de refoulement ou de pression (5) de l'aube est dégrossi à la meule, au moins jusqu'au plan de raccordement du bord d'attaque et du bord de fuite.
EP88105239A 1987-05-04 1988-03-31 Procédé de fabrication par meulage de pièces profilées et aube de turbine ainsi fabriquée Expired - Lifetime EP0290773B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88105239T ATE63709T1 (de) 1987-05-04 1988-03-31 Verfahren zum herstellen von profilteilen durch schleifen und entsprechend hergestellte turbomaschinenschaufel.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3714805 1987-05-04
DE3714805 1987-05-04

Publications (2)

Publication Number Publication Date
EP0290773A1 EP0290773A1 (fr) 1988-11-17
EP0290773B1 true EP0290773B1 (fr) 1991-05-22

Family

ID=6326799

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88105239A Expired - Lifetime EP0290773B1 (fr) 1987-05-04 1988-03-31 Procédé de fabrication par meulage de pièces profilées et aube de turbine ainsi fabriquée

Country Status (5)

Country Link
US (2) US5205081A (fr)
EP (1) EP0290773B1 (fr)
JP (1) JPS63288631A (fr)
AT (1) ATE63709T1 (fr)
DE (1) DE3862891D1 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5430936A (en) * 1993-12-27 1995-07-11 United Technologies Corporation Method for making gas turbine engine blade attachment slots
US7769513B2 (en) 2002-09-03 2010-08-03 Automotive Technologies International, Inc. Image processing for vehicular applications applying edge detection technique
DE10035224A1 (de) * 2000-07-20 2002-01-31 Man Turbomasch Ag Ghh Borsig Verfahren und Rohling zum Herstellen von rhomboidischen Schaufeln für axiale Strömungsmaschinen
US7676062B2 (en) 2002-09-03 2010-03-09 Automotive Technologies International Inc. Image processing for vehicular applications applying image comparisons
US6883234B2 (en) 2002-10-07 2005-04-26 United Technologies Corporation Process for machining axial blade slots in turbine disks for jet engines
DE10328310A1 (de) * 2003-06-23 2005-01-13 Alstom Technology Ltd Verfahren zum Modifizieren der Kopplungsgeometrie bei Deckbandsegmenten von Turbinenlaufschaufeln
DE102004021866A1 (de) * 2004-05-04 2005-12-01 Weigl Engineering Gmbh Verfahren zum Steuern einer Bearbeitungsmaschine
US7708619B2 (en) * 2006-05-23 2010-05-04 Saint-Gobain Abrasives, Inc. Method for grinding complex shapes
US7303461B1 (en) 2006-12-05 2007-12-04 Pratt & Whitney Canada Corp. Method of machining airfoils by disc tools
US7658665B2 (en) * 2007-10-09 2010-02-09 Saint-Gobain Abrasives, Inc. Techniques for cylindrical grinding
US7846010B2 (en) * 2008-09-10 2010-12-07 United Technologies Corporation Notched grind wheel and method to manufacture a rotor blade retention slot
EP2601015B1 (fr) 2010-08-06 2023-05-10 Saint-Gobain Abrasives, Inc. Outil abrasif et procédé pour finir des formes complexes dans pièces à travailler
FR3006616B1 (fr) * 2013-06-05 2016-03-04 Snecma Preforme d'aube de turbomachine

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR963320A (fr) * 1947-03-18 1950-07-05
US2606406A (en) * 1950-03-21 1952-08-12 Niles Bement Pond Co Blade finishing machine
US2656651A (en) * 1950-10-10 1953-10-27 Ex Cell O Corp Abrading machine
DE1946749A1 (de) * 1968-09-19 1970-05-06 Toyoda Machine Works Ltd Verfahren und Vorrichtung zum Schleifen mit hoher Schleifgeschwindigkeit
GB1242473A (en) * 1969-08-07 1971-08-11 Vni Instrument Inst Machine for closed-contour grinding of parts with variable curvature
US4031368A (en) * 1972-04-17 1977-06-21 Verkstadsteknik Ab Adaptive control of cutting machining operations
DE2243863A1 (de) * 1972-07-03 1974-01-17 Stork Koninklijke Maschf Vorrichtung, insbesondere eine schleif- oder scheuervorrichtung, zum bearbeiten von schaufeln von stroemungsmaschinen
SU484977A1 (ru) * 1974-03-26 1975-09-25 Одесское специальное конструкторское бюро специальных станков Способ автоматической настройки на оптимальный режим шлифовани
IT1013609B (it) * 1974-05-09 1977-03-30 Finike Italiana Marpuss Soc In Metodo e relativa apparecchiatura per il comando e la regolazione dei cicli di lavorazione di una macchina utensile
JPS5830110B2 (ja) * 1974-09-03 1983-06-27 セイコ−セイキ カブシキガイシヤ ケンサクカコウセイギヨソウチ
US3984213A (en) * 1974-11-06 1976-10-05 United Technologies Corporation Slow grinding technique
US4118900A (en) * 1976-03-29 1978-10-10 Seiko Seiki Kabushiki Kaisha Method for controlling grinding process
US4117634A (en) * 1977-01-31 1978-10-03 Seiko Seiki Kabushiki Kaisha Controlling method for a grinding machine
GB1596635A (en) * 1977-07-26 1981-08-26 Newall Eng Cam machining
US4193314A (en) * 1978-03-22 1980-03-18 General Motors Corporation Timing chain snubber
US4420685A (en) * 1979-08-24 1983-12-13 Hitachi Seiko, Ltd. Method and equipment for detecting tool failure
DE3005606C2 (de) * 1980-02-15 1992-08-27 Hauni-Werke Körber & Co KG, 2050 Hamburg Numerisch gesteuerte Maschine zum Schleifen mehrerer unterschiedlicher Flächen an ein- und demselben Werkstück
US4553355A (en) * 1981-03-30 1985-11-19 Energy-Adaptive Grinding, Inc. Grinding control methods and apparatus
DE3221395A1 (de) * 1982-06-05 1983-12-08 Werner Gerhard 6113 Babenhausen Lang Doppelspindel-schleifmaschine
US4827675A (en) * 1987-07-09 1989-05-09 United Technologies Corporation Method and apparatus for forming a curved slot

Also Published As

Publication number Publication date
US5330326A (en) 1994-07-19
DE3862891D1 (de) 1991-06-27
EP0290773A1 (fr) 1988-11-17
ATE63709T1 (de) 1991-06-15
JPS63288631A (ja) 1988-11-25
US5205081A (en) 1993-04-27

Similar Documents

Publication Publication Date Title
DE69728772T2 (de) Verbesserungen mit bezug auf schleifverfahren
EP2149425B1 (fr) Procédé et dispositif de fabrication d'un rotor de compresseur à vis
EP0290773B1 (fr) Procédé de fabrication par meulage de pièces profilées et aube de turbine ainsi fabriquée
EP1430983B1 (fr) Méthode pour formage électrochimique
EP1824627B1 (fr) Procédé et machine pour usiner des logements de paliers d'arbres
EP2117774B1 (fr) Procédé pour produire un verre de lunettes
EP1174210B1 (fr) Procédé et ébauche pour fabriquer des aubes rhomboidales pour machines axiales a fluide
EP0772509A1 (fr) Procede et dispositif permettant de meuler des cames a flancs concaves
EP1177067A1 (fr) Procede de meulage de surfaces de roulement convexes et de diametres exterieurs, sur des pieces a usiner ondulees, dans un serrage, ainsi que meuleuse destinee a la mise en oeuvre de ce procede
WO2017157698A1 (fr) Procédé pour l'usinage complet par meulage de pièces ondulées présentant des parties cylindriques et profilées
DE3415332A1 (de) Verfahren zum herstellen eines raeumwerkzeugs
DE19918289A1 (de) Verfahren zum Herstellen verzahnter Werkstücke
DE10163040C1 (de) Werkzeug zum Herstellen eines Gelenkinnenteils für ein Gleichlaufdrehgelenk
DE3523274A1 (de) Rundraeummaschine
DE2545565A1 (de) Vorrichtung zur formung eines tragflaechenprofils
AT516093B1 (de) Verfahren und Vorrichtung zur Bearbeitung eines Rohlings
EP4028215B1 (fr) Procédé de réalisation d'un rotor d'un compresseur à vis ou d'une pièce dotée d'un profil hélicoïdal
EP0327657A1 (fr) Procédé de fabrication d'une roue à aubes
DE602005002993T3 (de) Verbesserungen betreffend das schleifen von zylindrischen flächen und daran angrenzenden seitenflächen
DE102018003898A1 (de) Hochglanzpolierverfahren und Verfahren zum Herstellen eines Hochglanzpolierwerkzeugs
EP3756809A1 (fr) Procédé de fabrication d'un composant d'engrenage et machine de rectification pour engrenages
DE10113301A1 (de) Verfahren und Vorrichtung zum Schleifen des Verzahnuungsprofils von Abwälzfräsern sowie Abwälzfräser
DE19725251A1 (de) Bauteile für Strömungsmaschinen
DE102023110601B3 (de) Bearbeitungsvorrichtung und Verfahren zur formgebenden Bearbeitung von optischen Linsen durch Materialabtrag mit einer Vorbearbeitungsmaschine und einer Feinbearbeitungsmaschine
EP2801431A1 (fr) Procédé de traitement d'une lame de scie et affûteuse à lames de scies

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: A1

Designated state(s): AT CH DE FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19881207

17Q First examination report despatched

Effective date: 19900608

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 63709

Country of ref document: AT

Date of ref document: 19910615

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3862891

Country of ref document: DE

Date of ref document: 19910627

ET Fr: translation filed
ITF It: translation for a ep patent filed

Owner name: STUDIO JAUMANN

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
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
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19920619

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19920622

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19920624

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19920701

Year of fee payment: 5

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

Ref country code: NL

Effective date: 19921001

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19930331

Ref country code: GB

Effective date: 19930331

Ref country code: CH

Effective date: 19930331

Ref country code: LI

Effective date: 19930331

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

Ref country code: FR

Effective date: 19931130

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19930331

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EAL Se: european patent in force in sweden

Ref document number: 88105239.3

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19980325

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19980519

Year of fee payment: 11

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

Ref country code: SE

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

Effective date: 19990401

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

Ref country code: DE

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

Effective date: 20000101

EUG Se: european patent has lapsed

Ref document number: 88105239.3

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

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050331