Magnet marker strip and a method of producing a magnetic marker strip

US6313746A · kind A · utility

Assignee

• Vacuumschelmze GmbH · DE

Inventors

• Kurt Emmerich · Alzenau, DE
• Giselher Herzer · Bruchköbel, DE

Key dates

• Filing date: Apr 24, 2000
• Grant date: Nov 6, 2001
• Expiry date: Apr 24, 2020

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T156/1097
• WIPO field: Control
• WIPO sector: Instruments

Abstract

The magnetic marker strip is formed of a signal strip made from ferromagnetic material with a low coercive force onto which there is applied ferromagnetic material whose coercive force is distinctly higher than that of the material of the signal strip. The signal strip is relatively long as compared with its width, and emits harmonic-containing signals in a first, unmagnetized state as a consequence of the magnetic field in the interrogation region and emits no harmonic-containing signal in a second state in this magnetic field. The ferromagnetic material with the larger coercive force is arranged in the form of a plurality of control elements at a spacing from one another on the signal strip, the width of the control elements being essentially equal to the width of the signal strip, and the control elements switching the signal strip into the first state when they are in a first, unmagnetized state, and switching the signal strip into the second state when they are in a second, magnetized state. The signal strip is cut to length from a tape made from an amorphous, ductile alloy that is virtually free from magnetostriction transversely to the longitudinal axis of the tape, and the …