Global Patent Index - EP 1049115 A1

EP 1049115 A1 2000-11-02 - Method and device for demagnetizing pieces of small thickness

Title (en)

Method and device for demagnetizing pieces of small thickness

Title (de)

Verfahren und Vorrichtung zur Entmagnetisierung dünner Produkte

Title (fr)

Procédé et dispositif pour la démagnétisation de produits de faible épaisseur

Publication

EP 1049115 A1 (FR)

Application

EP 00420062 A

Priority

FR 9905572 A

Abstract (en)

The system uses very short pulses of reducing magnitude to achieve demagnetization. The process for demagnetization of thin ferromagnetic products includes placement of the products within a free zone which surrounded by an electrical coil. Current is applied to the coil in a series of pulse trains (T1, T2, ... Tn). Each train compri the same integer number of pulses (N) which are very short and of the same polarity within a train. Positive pulse trains (T1, T alternate with negative pulse trains (T2, T4..). The intensities of the pulse trains decrease with time from the largest amplitu initial pulse train (T1) to the last pulse train (Tn).

Abstract (fr)

L'invention concerne la démagnétisation de produits ferromagnétiques de faible épaisseur, mais pouvant occuper un volume important. A cet effet on envoie, dans au moins un bobinage entourant une zone libre où sont placés les produits à démagnétiser, des impulsions de courant électrique réparties en trains d'impulsions successifs (T1, T2, ..., Tn) qui comprennent chacun un nombre entier (N) d'impulsions très courtes de même signe, en faisant alterner des trains d'impulsions positives (T1, T3, ...) et des trains d'impulsions négatives (T2, T4,...). Les intensités de ces trains d'impulsions sont décroissantes dans le temps, depuis le premier train d'impulsions (T1) jusqu'au dernier (Tn). <IMAGE>

IPC 1-7 (main, further and additional classification)

H01F 13/00

IPC 8 full level (invention and additional information)

H01F 13/00 (2006.01)

CPC (invention and additional information)

H01F 13/006 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE ES GB IT

EPO simple patent family

EP 1049115 A1 20001102; FR 2793066 A1 20001103; FR 2793066 B1 20011012; JP 2000357611 A 20001226

INPADOC legal status


2004-06-16 [18D] DEEMED TO BE WITHDRAWN

- Effective date: 20031216

2003-09-17 [17Q] FIRST EXAMINATION REPORT

- Effective date: 20030804

2001-07-18 [AKX] PAYMENT OF DESIGNATION FEES

- Free text: DE ES GB IT

2001-07-18 [AXX] PAYMENT OF EXTENSION FEES

- Free text: AL PAYMENT 20010502;LT PAYMENT 20010502;LV PAYMENT 20010502;MK PAYMENT 20010502;RO PAYMENT 20010502;SI PAYMENT 20010502

2001-04-18 [RAP1] TRANSFER OF RIGHTS OF AN EP PUBLISHED APPLICATION

- Owner name: WALKER BRAILLON MAGNETICS

2001-03-14 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20010115

2000-11-02 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): DE ES GB IT

2000-11-02 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

- Free text: AL;LT;LV;MK;RO;SI