Metal detection apparatus for agricultural harvester
US5444966A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1994 |
| Grant date | Aug 29, 1995 |
| Priority date | — |
| Expiry date | Feb 3, 2014 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01D75/187
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An agricultural harvesting machine having feed rolls for feeding crop material along a feed path to a cutterhead which chops the crop material is provided with a metal detector for detecting ferrous metal objects passing along the feed path. The metal detector comprises a plurality of magnets and a plurality of generally planar Hall effect sensing elements. The magnets collectively produce a detection field which extends into the crop feed path. Each sensing element is disposed such that the magnetic field produced by two adjacent magnets is normal to the plane of the sensing element. In addition the sensing elements are disposed in a plurality of planes all normal to the crop feed path. However, the sensing elements are disposed in planes oriented at different angles relative to the direction of crop feed. When a ferrous metal object passes through the detection field it varies the density of the magnetic field at one or more of the transducers and the Hall effect causes an output voltage signal to be developed across the output leads. The output signal is applied through processing circuitry to a stop apparatus to stop the feed rolls. The transducers are mounted on a circuit boar…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.