EP0741630B1 - Verbesserungen in/oder im verband mit schleifbearbeitung - Google Patents

Verbesserungen in/oder im verband mit schleifbearbeitung Download PDF

Info

Publication number
EP0741630B1
EP0741630B1 EP95906426A EP95906426A EP0741630B1 EP 0741630 B1 EP0741630 B1 EP 0741630B1 EP 95906426 A EP95906426 A EP 95906426A EP 95906426 A EP95906426 A EP 95906426A EP 0741630 B1 EP0741630 B1 EP 0741630B1
Authority
EP
European Patent Office
Prior art keywords
cam
grinding
grinding wheel
camshaft
workpiece
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
EP95906426A
Other languages
English (en)
French (fr)
Other versions
EP0741630A1 (de
Inventor
Christopher D. Bartlett
Clive J. S. Midgley
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.)
Intermec Europe Ltd
Original Assignee
Unova UK 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 Unova UK Ltd filed Critical Unova UK Ltd
Publication of EP0741630A1 publication Critical patent/EP0741630A1/de
Application granted granted Critical
Publication of EP0741630B1 publication Critical patent/EP0741630B1/de
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
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/08—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section
    • B24B19/12—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section for grinding cams or camshafts
    • B24B19/125—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section for grinding cams or camshafts electrically controlled, e.g. numerically controlled

Definitions

  • This invention relates to a method of grinding, and more especially to the rough grinding of a workpiece having one or more lobes, such as a camshaft cam, and also to a grinding machine for performing such method.
  • Rough grinding of fixed workpieces is conventionally carried out by a progressive infeed/outfeed movement of the grinding wheel of increasing depth, so that parts of the workpiece requiring maximum grinding are only worked upon at the end of the progression of feed movements.
  • the conventional method has the disadvantage that a retraction mark is left on the workpiece at the point where the wheel and workpiece finally separate, especially since the workpiece profile at the point of retraction will be a point of maximum depth of grinding.
  • EP-A-0085225 there is disclosed a machine for rough grinding a cam in which the grinding wheel first contacts the workpiece cam at the centre of the cam nose, ie at the peak of the cam lobe, and removes material from the cam during two rotations thereof.
  • the amount removed during the first rotation is greater than that at the second rotation, the cam being rotated in accordance with a selected velocity curve, including acceleration/deceleration segments.
  • a method of rough grinding a cam within a maximum of two rotations of the cam workpiece relative to a grinding wheel wherein rotation of the cam and operation of the cam/grinding wheel infeed/outfeed are synchronised to cause the grinding wheel first to contact and engage the workpiece and, as infeed continues, to remove material so that the radius of the peak of the cam lobe is attained at the intended position of the peak as it becomes aligned with the grinding wheel with rotation of the workpiece, and thereafter, by continued rotation of the workpiece and infeed/outfeed operation, remove material from the workpiece so as to attain the required contour of the remainder of the cam, and finally breaking contact with the ground face of the cam, characterised in that the first contact between the workpiece and the grinding wheel is ahead of the intended position of the peak of the cam lobe therearound, and in that finally contact with the ground face is broken, at or after the peak of the lobe has become aligned with the grinding wheel for a second time but before the third such alignment.
  • Finish grinding may be carried out with the same or a different grinding wheel, or by means of a belt grinder.
  • Surface hardening may be interposed between rough grinding and finish grinding.
  • a grinding machine for carrying out the above defined method, equipped with control means for synchronising workpiece rotation and infeed/outfeed movement of the grinding wheel and cam.
  • This machine is defined in claim 5.
  • the cam for example, may be a cam on a camshaft, which typically requires to be ground with a plurality of lobed cams.
  • camshaft indexing along its axis from one cam workpiece to the next is synchronised relative to the infeed/outfeed movements of the grinding wheel and to the camshaft, so that the next cam workpiece is engaged by the grinding wheel.
  • a camshaft grinding machine comprising a bed, means for supporting and rotating a camshaft to be ground relative to a grinding wheel, infeed/outfeed drive means for moving the cam and grinding wheel relative to each other, first position sensing means for determining the distance between the longitudinal axis of the camshaft and the nearest point thereto on the surface of the grinding wheel, second position sensing means for determining the angular position of the rotating camshaft, control means responsive to signals from the two position sensing means to control the drive means, means containing radius data relative to rotational shaft position and means for utilising the radius/position data to control the infeed/outfeed drive means to remove more or less material from the camshaft to attain the desired profile around the camshaft in not more than two rations of the camshaft, characterised in that the drive means are controlled such that the wheel and the camshaft are caused to engage just prior to when the region of maximum radius of the cam lobe to be ground becomes aligned with a plane containing the axis
  • the method in accordance with the invention has the advantage that rough grinding can be performed much more quickly, specifically in little more than one turn of the cam workpiece. Moreover, because the grinding wheel separates from the cam at the nose position, the presence of a retraction mark can be substantially avoided. Thus, if desired, the grinding wheel can dwell for a short period at the depth of the nose, separation being produced by the continued rotation of the rough ground cam.
  • Figure 1 shows a grinding wheel 10 and a cam workpiece 12.
  • a grinding machine on which the grinding wheel 10 is located comprises a bed, means for supporting and rotating a camshaft to be ground relative to a grinding wheel and infeed/outfeed drive means for moving the cam and grinding wheel relative to each other.
  • First position sensing means is provided for determining the distance between the longitudinal axis of the shaft and the nearest point thereto on the surface of the grinding wheel 10 and second position sensing means for determining the angular position of the rotating camshaft 12.
  • a control means responsive to signals from the two position sensing means controls the drive means to cause the wheel 10 and camshaft 12 to engage just prior to when the region of maximum radius of the cam lobe to be ground becomes aligned with a plane containing the axis of the wheel and the axis of the shaft.
  • Means containing radius data relative to rotational shaft position and means for utilising the radius position data are used to control the infeed/outfeed drive means to remove more or less material from the camshaft to attain the desired radius profile around the camshaft in one but not more than two rotations of the camshaft.
  • the grinding wheel 10 is rotating clockwise about its axis, and the cam workpiece 12 is rotating anti-clockwise about its axis.
  • a controlled infeed/outfeed movement of the grinding wheel is taking place by relative displacement of the grinding wheel axis and the axis of the workpiece.
  • the workpiece 12 is pre-formed ready for rough grinding to produce a cam having a lobe 14.
  • the material to be ground away from the workpiece is indicated by the shaded border 16, the interior dashed line indicating the size and shape required for the rough ground cam.
  • the infeed/outfeed movement of the grinding wheel 10 is synchronised with the rotary movement of the workpiece 12 so that the grinding wheel first engages the workpiece just ahead of the nose of the required cam lobe 14.
  • Figure 1 shows the condition just before initial engagement takes place.
  • Figure 3 shows the condition when the workpiece has rotated through about 180 degrees from the condition shown in Figure 2.
  • One side of the workpiece has been wholly ground away, and material 16A to be ground away remains only on the other side of the workpiece.
  • This material 16A is ground away as rotation of the cam workpiece 12 continues in synchronised relationship to the controlled infeed/outfeed movement, until the starting position of the workpiece is reached. Grinding then continues to remove the sloping step initially cut into the workpiece ahead of the nose of the lobe.
  • the grinding wheel 10 is allowed for a short period to dwell without movement relative to the cam, so that disengagement of the wheel and cam is produced by the continued rotation of the cam.
  • the rough ground cam is thereby fully formed in just over one complete rotation of the workpiece.
  • the cam may be one cam of a series along a camshaft.
  • relative longitudinal indexing of the shaft and grinding wheel may be carried out, in synchronised relationship to the infeed/outfeed movement and shaft rotation, so that commencement of grinding of the next cam workpiece occurs when the next cam reaches the condition shown in Figure 1, i.e. in less than one rotation of the shaft.
  • Conventional finish grinding may be carried out subsequently, possibly by the same grinding wheel, and possibly after a surface hardening treatment carried out on the rough ground cams.
  • workpiece 12 is described as rotating anticlockwise, it is to be understood that it may alternatively rotate in a clockwise sense.
  • Figure 5 shows the position of zero degree reference on a cam 18 which defines the position from which relative angles for the control of the synchronisation between the cam and the grinding wheel are determined.
  • the cam 18 has a maximum radius with respect to the centre of cam rotation as shown by line 20. This radius is chosen to be a zero degree reference line.
  • the cam 18 is defined at zero degrees with respect to the grinding wheel 22 when the cam zero reference is pointing horizontally towards the grinding wheel centre 22.
  • the zero degree reference line 20 is further referenced to an angular measuring system coincident with the axis of cam rotation. Rotation of the reference line 20 relative to its initial position produces an angular rotation which is measured by the angular measuring system.
  • the relative angle is read by a computer controlling the grinding machine and a signal fed from the computer to the grinding machine so as to synchronise movement of the cam 18 and the grinding wheel 22.
  • Figure 6 describes the steps required to synchronise the grinding of the cam 18 with rotation of the grinding wheel 22.
  • the cam 18 is indexed to zero, plus or minus an angular offset.
  • the offset is stored in the controlling computer by a machine operator. The size of the offset depends on the direction of rotation of the cam 18 during grinding, i.e. whether the rotation is clockwise or anti-clockwise.
  • the grinding wheel 22 is moved forward until its surface is positioned so as to contact the rotating cam 18 when the maximum throw of the cam, as defined along line 20 in Figure 5, aligns with the line joining the centre of rotation of the cam 18 and the grinding wheel 22.
  • Cam rotation in the desired direction of grinding is started and when the cam 18 is at zero degrees with respect to the grinding wheel 22, the latter 22 is moved linearly with respect to the horizontal axis along which the zero degree reference to the cam was initially defined.
  • the grinding wheel movement is controlled by (cam angle/grinding wheel position) coordinates as specified by the controlling computer in accordance with the cam profile to be ground. After 360 degrees of rotation when the maximum radius of the cam is back at the zero degrees reference position, the linear motion of the grinding wheel 22 is stopped.
  • the cam 18 is rotated through an angle controlled by the machine control computer, as specified by a machine operator, and stopped.
  • the grinding wheel 22 no longer contacts the cam 18 at any position and the wheel 22 is retracted away from the cam 18.
  • the roughly ground cam is then removed.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)

Claims (7)

  1. Verfahren zum Grobschleifen eines Nockens mit maximal zwei Umdrehungen eines Nocken-Werkstückes (12) relativ zu einem Schleifrad, wobei die Drehung des Nockens und der Betrieb der Nocken/Schleifrad-Zustellung/Rückstellung so synchronisiert werden, daß das Schleifrad zuerst mit dem Werkstück in Kontakt und in Eingriff kommt, und bei fortschreitender Zustellung fortfährt, Material abzunehmen, so daß der Radius der Spitze der Kurvenerhöhung an der gewünschten Stelle der Spitze erreicht wird, wenn sie mit dem Schleifrad bei einer Drehung des Werkstückes ausgerichtet wird, und im Anschluß daran durch fortgesetzte Drehung des Werkstückes und des Zustellungs/Rückstellungs-Betriebes Material von dem Werkstück abnimmt, damit die gewünschte Kontur des übrigen Teils des Nockens erreicht wird, und schließlich der Kontakt mit der geschliffenen Fläche des Nockens unterbrochen wird, dadurch gekennzeichnet, daß der anfängliche Kontakt zwischen dem Werkstück (12) und dem Schleifrad (10) räumlich vor der beabsichtigten Position der Spitze der Nockenerhöhung (14) darum herum hergestellt wird, und daß der Kontakt mit der geschliffenen Fläche endgültig unterbrochen wird, wenn oder nachdem die Spitze der Erhöhung mit dem Schleifrad ein zweites Mal ausgerichtet worden ist, jedoch bevor die dritte Ausrichtung erfolgt.
  2. Verfahren zum Grobschleifen nach Anspruch 1, dadurch gekennzeichnet, daß zum Feinschleifen ein Schleifrad verwendet wird.
  3. Verfahren zum Grobschleifen nach Anspruch 1, dadurch gekennzeichnet, daß zum Feinschleifen ein Schleifband verwendet wird.
  4. Verfahren zum Grobschleifen eines Nockens mit einer Nockenerhöhung (14) nach einem der Ansprüche 1 - 3, dadurch gekennzeichnet, daß als weiterer Schritt die Oberfläche des Nockens (12) vor dem Feinschleifen gehärtet wird.
  5. Schleifmaschine zum Grobschleifen eines Nockens, mit einer Steuervorrichtung zum Synchronisieren der Werkzeugdrehung und der Zustellungs/Rückstellungs-Bewegung eines Schleifrades (10) und Nockens (12), um ein Grobschleifen des Nockens in eine gewünschte Kontur zu erzielen, dadurch gekennzeichnet, daß zur Durchführung des Verfahrens nach Anspruch 1 die Steuervorrichtung das Schleifrad zunächst in Kontakt mit dem Nocken räumlich vor der beabsichtigten Position des Spitzenwertes der Nockenerhöhung (14) bringt.
  6. Schleifmaschine nach Anspruch 5, bei der die Nockenwelle, die längs ihrer Achse von einem Nockenwerkstück (12) zum nächsten weitergeschaltet wird, relativ zu den Zustellungs/Rückstellungs-Bewegungen des Schleifrades (10) und zu der Nockenwelle synchronisiert wird, derart, daß das nächste Nockenwerkstück von dem Schleifrad beaufschlagt wird.
  7. Nockenwellen-Schleifmaschine mit einem Bett, einer Vorrichtung zum Abstützen und Drehen einer zu schleifenden Nockenwelle relativ zu einem Schleifrad, einer Zustellungs- / Rückstellungs-Antriebsvorrichtung zum Bewegen des Nockens und des Schleifrades relativ zueinander, einer ersten Positions-Feststellvorrichtung zur Bestimmung des Abstandes zwischen der Längsachse der Nockenwelle und dem nächsten Punkt auf der Oberfläche des Schleifrades, einer zweiten Positions-Feststellvorrichtung zur Bestimmung der Winkelposition der sich drehenden Nockenwelle, einer Steuervorrichtung, die auf Signale aus den beiden Positions-Feststellvorrichtungen anspricht, um die Antriebsvorrichtung zu steuern, einer Radiusdaten relativ zu der Drehwellenposition enthaltenden Vorrichtung, und einer Vorrichtung zur Verwendung der Radius/Positions-Daten für die Steuerung der Zustellungs-/Rückstellungs-Antriebsvorrichtung, um mehr oder weniger Material von der Nockenwelle abzunehmen und damit das gewünschte Profil um die Nockenwelle in nicht mehr als zwei Drehungen der Nockenwelle zu erzielen, dadurch gekennzeichnet, daß die Antriebsvorrichtung so gesteuert ist, daß das Rad und die Nockenwelle unmittelbar vor dem Zeitpunkt, zu dem der Bereich des maximalen Radius der zu schleifenden Nockenerhöhung mit einer die Achse des Rades und die Achse der Nockenwelle aufnehmenden Ebene ausgerichtet wird.
EP95906426A 1994-01-26 1995-01-25 Verbesserungen in/oder im verband mit schleifbearbeitung Expired - Lifetime EP0741630B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB9401462 1994-01-26
GB9401462A GB9401462D0 (en) 1994-01-26 1994-01-26 Improvements in and relating to grinding
PCT/GB1995/000146 WO1995020467A1 (en) 1994-01-26 1995-01-25 Improvements in or relating to grinding

Publications (2)

Publication Number Publication Date
EP0741630A1 EP0741630A1 (de) 1996-11-13
EP0741630B1 true EP0741630B1 (de) 1999-03-03

Family

ID=10749343

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95906426A Expired - Lifetime EP0741630B1 (de) 1994-01-26 1995-01-25 Verbesserungen in/oder im verband mit schleifbearbeitung

Country Status (6)

Country Link
EP (1) EP0741630B1 (de)
AU (1) AU1462295A (de)
DE (1) DE69508060T2 (de)
ES (1) ES2128040T3 (de)
GB (2) GB9401462D0 (de)
WO (1) WO1995020467A1 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2357722B (en) * 1999-10-27 2003-05-07 Unova Uk Ltd Workpiece grinding method which achieves a constant stock removal rate
CN102229083A (zh) * 2011-06-08 2011-11-02 潘旭华 一种带凹凸轮的磨削方法
CN103707160B (zh) * 2014-01-13 2016-01-20 北京信息科技大学 凸轮磨削加工过渡廓形规划方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4443976A (en) * 1982-01-29 1984-04-24 Litton Industrial Products, Inc. Cylindrical grinding machine
DE3529099A1 (de) * 1985-08-14 1987-02-19 Fortuna Werke Maschf Ag Verfahren und vorrichtung zum spanabhebenden bearbeiten einer oberflaeche von profilen mit einer von einer kreisform abweichenden kontur, insbesondere nockenwellen
HU209638B (en) * 1989-10-27 1994-09-28 Miskolci Egyetem Method and apparatus for generating machining with abrasive belt
US5165202A (en) * 1991-10-18 1992-11-24 Spindel Jr Gilbert D Methods and apparatus for making spectacle frame lens patterns

Also Published As

Publication number Publication date
GB2285937B (en) 1997-08-20
EP0741630A1 (de) 1996-11-13
WO1995020467A1 (en) 1995-08-03
DE69508060T2 (de) 1999-07-01
GB9401462D0 (en) 1994-03-23
AU1462295A (en) 1995-08-15
GB2285937A (en) 1995-08-02
DE69508060D1 (de) 1999-04-08
GB9501409D0 (en) 1995-03-15
ES2128040T3 (es) 1999-05-01

Similar Documents

Publication Publication Date Title
US10583507B2 (en) Method for machining a workpiece, tool arrangement and tooth cutting machine
US4961289A (en) Machine tool for fine machining the tooth flanks of pretoothed gearwheels
US4747236A (en) Method for working, by metal-cutting processes, the surfaces of profiles having a non-circular contour, in particular camshafts
CA2221156A1 (en) Improvements in and relating to machine tools
US5919081A (en) Method and apparatus for computer numerically controlled pin grinder gauge
EP0085225B1 (de) Zylindrische Schleifmaschine
EP1621287B1 (de) Verfahren und Vorrichtung zum Schleifen von Nocken mit Hohlflächen
EP0741630A1 (de) Verbesserungen in/oder im verband mit schleifbearbeitung
EP1235662B1 (de) Computergesteuerte schleifmaschine
US4744179A (en) Process for controlling tool infeed at machining start of a gear cutting machine
US20230264280A1 (en) Method for machining and producing a toothed portion on a workpiece
EP0675780B1 (de) WERKSTÜCKSCHLEIFVORRICHTUNG UND WERKSTüKSCHLEIFVERFAHREN
US5191739A (en) Method and apparatus for lapping gear teeth while changing at least one of load torque, rotating speeds and rate of teeth contact point movement of the gears
US5616070A (en) Work drive orienting system for machine tool
JP3850224B2 (ja) 研削加工方法及び数値制御研削盤
US3977126A (en) Grinding machine
JPH0632894B2 (ja) カム研削装置
JP7863013B2 (ja) 研削盤及び研削方法
JPH0760622A (ja) ツイストエンドミル用研削装置
GB2273899A (en) Grinding method and apparatus
JPS62107947A (ja) ブロ−チ自動研削方法
SU808329A1 (ru) Станок дл огранки вставок юве-лиРНыХ издЕлий
JP3348877B2 (ja) 平面研削盤のトラバース研削方法
US20030097747A1 (en) Method of machining a part
SU965717A1 (ru) Устройство дл загрузки деталей

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

17P Request for examination filed

Effective date: 19960418

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR IT

RIN1 Information on inventor provided before grant (corrected)

Inventor name: MIDGLEY, CLIVE J. S.

Inventor name: BARTLETT, CHRISTOPHER D.

17Q First examination report despatched

Effective date: 19971126

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

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

Owner name: UNOVA U.K. LIMITED

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

ITF It: translation for a ep patent filed
AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR IT

REF Corresponds to:

Ref document number: 69508060

Country of ref document: DE

Date of ref document: 19990408

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2128040

Country of ref document: ES

Kind code of ref document: T3

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

Ref country code: FR

Payment date: 20060117

Year of fee payment: 12

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

Ref country code: ES

Payment date: 20060126

Year of fee payment: 12

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

Ref country code: IT

Payment date: 20060131

Year of fee payment: 12

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

Ref country code: DE

Payment date: 20060228

Year of fee payment: 12

REG Reference to a national code

Ref country code: FR

Ref legal event code: TP

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: 20070801

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20070930

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20070126

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: 20070131

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

Ref country code: ES

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

Effective date: 20070126

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

Effective date: 20070125