Patent · US Expired

Stone detector for harvesting machines

US4353199A · kind A · utility

20Cited by
11References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 15, 1981
Grant dateOct 12, 1982
Priority date
Expiry dateApr 15, 2001

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01V1/001
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

The unpredictability of the actual characteristics of spurious sounds has resulted in the use of electronic filtering or comparator circuits being less than satisfactory in certain cases, such as for distinguishing between machinery sounds and foreign objects in the machinery. An acoustically based stone detector is provided for use on a field harvesting machine. A piezoelectric acoustic detector is attached to the central support web of a feed roll within the frame of the harvester, and a rotating transformer is used to transmit the signal from the feed roll to the frame. The air core rotating transformer is built with one coil rotating with the feed roll and the other coil stationary on the frame. Electronic circuitry is used to process the signal and control the harvester action to protect the cutter blades from damage by detected stones, either by stopping the machine or mechanically ejecting the stones.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.