DIGITAL WEIGHING APPARATUS

摘要

Apparatus for feeding a product to a weighing scale and stopping the feed when the amount of product fed reaches a final weight. A scale having a balance portion to receive product to be weighed is movable from an initial position toward a balance position as product is delivered thereto. The balance portion of the scale starts to move upon delivery thereto of a predetermined initial weight of product. First and second product feeds are activated at the start of a weighing operation for delivering a quantity of product from a source thereof to the balance portion of the scale. The first feed delivers product at a first rate of speed and the second feed delivers product at a second and slower rate of speed. A sensor detects movement of the balance portion of the scale in either of two directions and provides first and second electrical outputs representative of the magnitude and direction of the movement thereof, each output always having one of two discrete states. Controls responsive to the sensor's outputs terminate operation of the first product feed when the amount of product delivered to the balance portion of the scale reaches a first predetermined level and terminate operation of the second product feed when the amount of product delivered to the balance portion of the scale reaches a second predetermined level substantially equal to the final weight of product to be delivered. The amount of product delivered to the balance portion of the scale after termination of operation of the second product feed brings the balance portion of the scale into its balance position indicating that the final weight of product to be delivered has been attained.