Apparatus for filling containers with prescribed quantity of product by weight

摘要

An article sensor which defines an opening through which articles to be measured are propelled in a non-supported condition. Bounding the opening are at least two mutually perpendicular arrays of light sources and of photodetectors. The photodetectors constitute the inputs to a microprocessor controlled circuit so that the number and identity of photodetectors that are obscured by a passing article can be determined rapidly thereby enabling plural measurements of articles dimensions to be made during traversal of a single article. The microprocessor can be programmed to compute the volume of an article, the weight of an article or virtually any other characteristic of an article. A container filling machine which is controlled by the abovementioned microprocessor so that the aggregate weight applied to each container can be carefully measured and controlled, thereby assuring compliance with relevant fair packaging and labeling regulations without the waste attending overfilling of such containers. A circuit for controlling and interrogating the photodetectors which permits interrogation of the photodetectors at a rate corresponding to that at which the microprocessor operates. The circuit in a first phase of operation senses the voltage drop across the phototransistor without significantly discharging current carriers from the base of the transistor and in a second phase totally discharges the base in preparation for a succeeding measurement so that determination of the condition of the photodetectors is achieved rapidly and accurately.