Metal detector for intake of field chopper

US4758788A · kind A · utility

Assignee

• VEB Kombinat Fortschritt Landmaschinen · DE

Inventors

• Burkhard Weiss · Wilthen, DE
• Arthur Hauschild · Neustadt in Sachsen, DE
• Erich Herrmann · Neustadt in Sachsen, DE

Key dates

• Filing date: Dec 23, 1986
• Grant date: Jul 19, 1988
• Expiry date: Dec 23, 2006

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A01D75/187
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus for detecting magnetically sensible objects in an object stream longitudinally passing a predetermined location, for instance at the intake end of the conveyor of a field chopper, has according to the invention a support at the location extending transversely adjacent the object stream and having a pair of transverse ends and a center therebetween and a magnet assembly on the support having a north pole directed from between one of the ends and the center of the support transversely of the support and of the stream into the crop stream and a south pole directed parallel to the north pole from between the other end and the center of the support. The assembly forms between its poles a magnetic field having lines of force extending mainly transversely through the stream. Respective north and south sensing coils at least partially surround the respective poles so that a magnetically sensible object perturbing the field will generate respective currents in the coils. Conductors connect the coils in series such that the currents generated therein by perturbation of the field by a magnetically sensible object are added together and a controller is connected to the coils for r…