| 摘要 |
508,544. Switching systems for consuming devices. GENERAL ELECTRIC CO., Ltd., COATES, H.J., and PRICE, A.'B. Dec. 30, 1937, No. 36096. [Class 38 (iv)] In a system comprising a plurality of feeders for feeding material, the operation of each feeder is controlled electrically, and the energization of each feeder control circuit is under the influence of a common master. control so that the number of operations of said feeders collectively in a given time is maintained below a predetermined value. An application to four tub tipplers feeding coal to a conveyer is described. When all four tipplers are at rest any one of them may be started by depressing a push button associated with it, thus energizing the operating coil of a contactor controlling the supply to a solenoid 3, 4, 5 or 6 and thereby removing a tub-stop to connect the tippler with its drive. If, say, push button 22 is depressed the operating coil of contactor 16 is energized from supply mains 1 and 2 through a number of normally closed contacts and contact 20 of a time delay switch which is common to the operating coil circuits of the contactors of all four tipplers. Operation of contactor 16 closes contacts 16a, 16b, 16c and opens a normally closed contact 16d, 16e, 16f in each of the other contactoroperating coil circuits. Contact 16b energizes solenoid 4 and starts the tippler. Contact 16a changes over with a make-before-break action so as to supply the operating coil circuit of contactor 16 independently of contact 20 of the time delay switch. Contact 16c energizes operating coil 19 on the time delay switch to open contact 20 instantaneously.. The opening of contacts 16d, 16e, 16f prevents the operation of other tipplers while push button 22 is depressed. When push button 22 is released, contactor 16 opens, thereby de-energizing 'solenoid 4 to return the tub stop, and contacts 16d, 16e, 16f are reclosed. Operating coil 19 on the time delay switch is also de-energized as a result of the opening of contactor 16 but closure of contact 20 is subject to a time delay so that further operation of any of the tipplers cannot take place till that time has elapsed. |
