Patent GB-329552-A (GB)
Title: Improvements in automatic-feed weighing apparatus
IPC: G01G13/30
Filed: 1929-06-25
Abstract: 329,552. Rumpf, E. June 25, 1929- Addition to 314,525. Automatic-feed weighers. -The electricallycontrolled automatic-feed weigher claimed in theparent Specification is modified by providing a separate circuit for the electromagnets actuating the feeding jigger, and incorporating an additional circuit, including a switch controlled by the weighbeam and an electromagnet, for reducing the jigger motion. As in the parent Specification, the vibrations of the feed shoot 14 are effected by two opposed electromagnets 11, 12 controlled by a buckling leaf spring 41, but in the present apparatus the electromagnets are continuously energized through a separate circuit I, when the apparatus is connected to the mains 108. After the main portion of the charge has entered the scale pan 48, the movement of the scale beam 5 withdraws a contact rod 73 from a mercury cup 76 and breaks a circuit VI, thus de-energizing an electromagnet 82 in the additional circuit. The armature 89 of the electromagnet is then rocked by a spring 90 so that one end of the armature is interposed between a pair of spring-pressed pincer-like levers 85 grasping a fork 39 on the vibrating feed shoot. This interposition restricts the vibratory movements of the feed shoot and reduces the feed. When the charge has been completed a second contact 75 is withdrawn from a mercury cup 78 and a circuit II is broken to de-energize a magnet 9 and cause a switch 102 to break a circuit VII containing a pair of electromagnets 95. These electromagnets release their armature 96 and permit a shutter 93, connected to the armature by links 100, 98, to close the bottom of a catch pin 91 situated between the feed shoot 14 and the scale pan 48. The feed to the scale pan is thus intercepted. An electromagnet 10 is also energized to open the discharge gates 55 of the pan and drop the weighed charge into a hopper 13. The consequent descent of the weight pan 50 dips the contact rod 73 into its mercury cup 76 and energizes the electromagnet 82, thus restoring the full vibratory feed. The energized electromagnet 10 also opens two switches 71, 72 to maintain the circuit II in an open condition, and to break a circuit IV. The breaking of the circuit IV allows a delay-action mercury switch to rotate and (after allowing sufficient time for the pan to empty) close a circuit V to energize an electromagnet 9<1>. The electromagnet 9<1> opens a switch 103 to de-energize the electromagnet 10 and allow the discharge gates 55 to close. The movement of the discharging mechanism closes the switch 71 and energizes the electromagnet 95, which thereupon opens the catch pan 91 and drops its contents into the scale pan, allowing also the feed from the vibrating shoot to pass straight through, whereupon the cycle of operations is repeated. A layer of oil in the mercury cups 73 - - 75 prevents sparking. In order to prevent the pan being temporarily opened when starting the apparatus, the main switch lever 109, when being moved, contacts first with a segment 110 and afterwards contacts with a segment 111 in the pan-opening circuit.