GB1007795A - Improvements relating to weighing apparatus - Google Patents

Abstract

1,007,795. Automatic feed weighers. W. & T. AVERY Ltd. July 12, 1963 [July 18, 1962], No. 27520/62. Heading G1W. In an automatic feed weigher pulverulent material in a duct 2 (Fig. 1) is fluidized by air under pressure admitted at a connection 3a to a space 3 beneath a porous floor 4, so that the material flows to a duct outlet which is controlled by a slide gate and thence to a weigh receptacle 17 supported on a steelyard 15. The slide gate has a slide 7 horizontally reciprocable by means of a hydraulic ram 8. Depending on the inclination of the steelyard the slide 7 is automatically positioned to provide either a full feed (Fig. 2 not shown), a dribble feed through a small aperture 7a (Fig. 3) or to cut off the feed (Fig. 4 not shown). The steelyard has counterweights 10 and means for controlling the slide gate including a boost lever 13 for giving a thrust partially counterbalancing the leverage of the counterweights 10 and microswitches 11, 12. In operation when the weight of material in the receptacle reaches a predetermined value a little short of the required value the rise of the left arm of the steelyard operates the micro-switch 12 which is arranged (by means not described) to actuate the ram 8 which then moves the slide 7 to the dribble feed position, and at the same time the boost lever 13 ceases to apply a thrust on the steelyard. The dribble feed continues until the weigh receptacle has received the required weight and, with due allowance for material "in suspension", the micro-switch 11 is operated by the steelyard whereby the ram closes the slide gate and simultaneously the fluidizing air supply is cut-off.