Metal detection in the vicinity of ferrous boundaries
AssigneeFord New Holland, Inc.
InventorsRichard P. Strosser, Carl E. Bohman, Mark K. Chow
Life of this patent
Estimating the term…
Abstract
In a forage harvester having a metal detector with permanent magnets located within a crop feed roll, additional permanent magnets are positioned beyond the ends of the feed roll and at a distance greater than the radius of the feed roll from the axis of rotation of the feed roll. The additional magnets cooperate with magnets within the feed roll to provide a more uniform flux density across the width of the feed roll, even in regions near ferrous side sheets defining the lateral limits of the harvester feed path. Tramp metal is thus detected with equal facility regardless of its trajectory past the feed roll.
Claims8
In a forage harvester having first and second feed rolls rotatable about first and second axes for feeding crop material through a crop feed path and a metal detector positioned within said first feed roll for detecting the presence of tramp metal passing between said feed rolls, said metal detector including first and second rows of permanent magnets for producing a magnetic field between said feed rolls to detect said tramp metal, the improvement comprising:
- first and second additional permanent magnets;
- and,
- support means for supporting said additional permanent magnets laterally of said crop feed path at a distance from the axis of said first feed roll which is greater than the radius of said first feed roll.
Dependencies are inferred from the claim text.