Improvements in or relating to compensated feed weighing machines

Abstract

Abstract 743,530. Automatic weight control systems. SIMON & SONS Ltd., R. Nov. 4, 1953 [Nov. 7, 1952], No. 28122/52. Class 38 (4). [Also in Group XVIII] In an automatic feed weigher of the type compensating for the suspended material at cut-off, the compensation (obtained either by loading the weighbeam or by adjusting the rate of feed) is automatically corrected after each weighing operation by a reversible electric motor. Material from an automatic feed, e.g. an endless conveyer driven electrically, or an electric vibrator or an electrically controlled gravity feed, is delivered to the weigh-pan 2, Fig. 1, suspended from a weighbeam 1 and weighed against a weight 3 on a rod 4. The pan 2 has a hinged delivery door 5 operable by a solenoid 12 via, levers 11, 10, pin 9 on sector 7, and lever 6. As the pan 2 fills and the rod 4 rises, a projection 20 on the weight rod 4 trips a bell crank 18 allowing a spring 17 to rotate an arm 16 and with it a shaft 124, thereby actuating a timing switch 2S, and, through a lost-motion linkage 15, 14, a feed control switch 1S. The bell crank 14 also rotates a shaft 122 (normally straight but shown curved for clarity) to open the hopper discharge interlock 22. The weight rod 4 also has a lug 21 for engaging a spring- loaded compensating bell crank 35 freely mounted on shaft 124. The normal weighing sequence is as follows. The timer switch 2S, Fig. 6, closes first, and energizes a motor T operating three cam-actuated mercury switches 27MS, 28MS, 29MS, Fig. 5 (not shown). The switch 27MS is a holding-in contact for switch 2S; switch 28MS energizes the automatic compensating device (see below); switch 29MS energizes the delivery door operating solenoid 12. Meanwhile switch 1S has opened to stop the feed motor 45, and the interlock 22, Fig. 1, now rides on the top of cam 7 to prevent switch 1S from being reclosed until the delivery door has roclosed. The compensating ball crank 35 is tensioned by springs 33, 34 which are adjusted by a screw and nut. operated by a reversible motor 30. This is controlled by a reversing switch 40S actuated by a projection 41 on the weight rod 4, in accordance with the actual (uncompensated) weight of material in the weighpan; because the rod 4 will have risen clear of the compensating bell crank 35 (which is held by a stop 37). Thus in accordance with any error in the actual weight delivered, the motor 30 adjusts the tension on the compensating springs 33, 34 during the period that the timing switch 28MS is closed. In a modification, Fig. 7 (not shown), the motor 30 adjusts a resistor in series with a vibrator conveyer instead of adjusting the compensating springs, and in a further modification, Fig. 8 (not shown), a weight may be adjusted along a balance compensator arm connected to the weigh beam. A counter for the number of weighs may be operated by the bell crank 14.

Inventors

• 👤 William George Simon

Bibliographic Details