Grain loss monitor
First Claim
1. A grain loss per unit area monitor for a variable speed combine adapted to harvest a crop and recover grain therefrom comprising, in combination,means including an electrical transducer adapted to be positioned in the flow path of grain in said combine for generating a grain flow rate signal which is a function of the number of grains of said crop impinging on said transducer,means for deriving a ground speed signal which is a function of the ground speed of said combine, andmeans for deriving a signal which is the analog of said grain flow rate signal divided by said ground speed signal, whereby said analog signal is indicative of grain loss per unit area and is independent of time.
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Accused Products
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.
52 Citations
25 Claims
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1. A grain loss per unit area monitor for a variable speed combine adapted to harvest a crop and recover grain therefrom comprising, in combination,
means including an electrical transducer adapted to be positioned in the flow path of grain in said combine for generating a grain flow rate signal which is a function of the number of grains of said crop impinging on said transducer, means for deriving a ground speed signal which is a function of the ground speed of said combine, and means for deriving a signal which is the analog of said grain flow rate signal divided by said ground speed signal, whereby said analog signal is indicative of grain loss per unit area and is independent of time.
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15. A grain loss per unit area monitor for a combine comprising, in combination,
means including an electrical transducer adapted to be positioned in the flow path of grain in said combine for generating a grain flow rate signal which is a function of the number of grains impacting on said transducer, means including a tachometer for deriving a unidirectional ground speed signal whose magnitude is inversely proportional to the ground speed of said combine, multiplier means for deriving the product of said grain flow rate signal and said unidirectional ground speed signal, and means for indicating the magnitude of the output from said multiplier means as a representation of the grain loss per unit area harvested by said combine.
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22. A grain loss monitor for a variable speed combine adapted to harvest a crop and recover grain therefrom comprising, in combination,
electrical transducer means adapted to be positioned in the flow path of grain in said combine for generating grain flow rate pulses when grains of said crop impinge thereon, a monostable multivibrator triggered by said grain flow rate pulses to generate fixed width output pulses, tachometer means coupled to said combine for deriving tachometer pulses at a frequency which is a function of the ground speed of said combine, integrator means for deriving a unidirectional ground speed signal whose magnitude is inversely proportional to the frequency of said tachometer pulses, multiplier chopper means turned on by said fixed width output pulses from said multivibrator for chopping said unidirectional ground speed signal, and means for indicating the average voltage of the output pulses from said chopper means as an analog of grain loss per unit area harvested by said combine.
Specification