Shearbar/cutterhead monitoring system with spatially separated magnet

US6255812A · kind A · utility

Assignee

• Deere & Company · US

Inventors

• Burkhard Voigt · Mannheim, DE
• Hagen Schaefer · Mannheim, DE
• Markus Braun · Mannheim, DE

Key dates

• Filing date: Mar 18, 1999
• Grant date: Jul 3, 2001
• Expiry date: Mar 18, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B7/14
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A system for monitoring a distance between a relatively movable magnetically conductive shearbar and a magnetically conductive cutterhead in a forage harvester includes a permanent magnet and an induction coil which generates an electric signal corresponding to the distance and which is supplied to an evaluation circuit. The evaluation circuit separates the signal generated by the induction coil into a high frequency component and a low frequency component and forms a quotient therefrom.