Metal locating device for crop conveyor

摘要

The arrangement has permanent magnets (M1-M3) fixed adjacent to each other in a hollow conveyor roller (W) in its shaft direction, with one pole (N) directed radially outwards so that its magnetic field passes out through the roller. The magnetic fields pass axially through sensor coils (S1-S3) that are also mounted in the roller. Each outwardly directed pole carries a pole shoe (P1-P3) that reaches in to near the roller, passes through the associated sensor winding and has a free pole surface (F1-F3) narrower than that of the permanent magnets so that the free pole shoe surface material carries more flux.