| 摘要 |
An electrical apparatus for sorting products according to their lengths. In this apparatus the products are passed through a scanning zone which is provided with a light sensitive cell and a source of illumination arranged so that illumination of the light sensitive cell is interrupted while the product is passing through the scanning zone and an electric pulse is generated while the product is in this zone. This pulse is transmitted from the photocell amplifier to the toggle flip-flop which provides one input to an And gate in the circuit which controls the energization of the solenoid valves controlling the air blasts that deflect the product according to their lengths. This pulse is also transmitted from the photocell amplifier to a signal expanding device which controls a gate between an oscillation generator and an electronic counter so that pulses are transmitted from this generator through this gate to the counter for the duration of the expanded pulse to provide a measure of the product length. The expanded pulse is also supplied to delay circuit to provide a strobe pulse to the logic of this apparatus which supplies three outputs corresponding to the long, medium and short product lengths. These outputs are connected to separate product length flip-flops which are connected to the And gates provided to the circuit controlling the air blast control valves. Each of the And gates have a pair of inputs, one of which is supplied by the output of the toggle flip-flop and the other of which is supplied by the product length flip-flops. Thus, the And gates control which of the air blast solenoid valves is to be energized. If the long product flip-flop supplies a signal to the long product And gate then the long product air blast valve is opened and if the medium or short flip-flop supplies the control signal to the medium or short And gate then the medium or short air blast valve is opened.
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