Patent · US Expired

Grain loss monitor

US3935866A · kind A · utility

36Cited by
4References
25Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 23, 1974
Grant dateFeb 3, 1976
Priority date
Expiry dateDec 23, 1994

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S56/15
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A grain loss monitor for a combine harvester derives a grain loss rate signal in accordance with the number of grains impinging on a transducer and a ground speed signal proportional to the ground speed of the combine and divides the former by the latter to derive an analog of grain loss per unit area which is independent of time. The preferred embodiment includes a one-shot multivibrator which is triggered to its unstable state to generate a fixed width pulse each time a grain kernel strikes the transducer, a tachometer coupled to the combine wheels and a period timed integrator triggered by tachometer pulses for deriving a unidirectional ground speed voltage inversely proportional to frequency of the tachometer pulses, a pulse frequency modulation chopper circuit turned on and off by the fixed width one-shot pulses and having its peak voltage controlled by the unidirectional ground speed signal for accomplishing division of grain loss rate by combine ground speed, and an averaging circuit for determining the average voltage of the chopper output pulses as an analog of grain loss per unit area.

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