Improvements in or relating to means for maintaining in synchronism a number of electric motors
Реферат: 259,285. Western Electric Co., Ltd., (Western Electric Co., Inc.). July 2, 1925. Systems depending on the use of two or more machines. - A number of series-type electric motors are provided with electrical interlocking means whereby the motors can be accelerated in synchronism with one another from an alternating-current supply. The motors are caused to run synchronously after a predetermined speed is attained. A particular motor employed, which forms the subject of Specification 260,929, [Class 35, Dynamo-electric generators &c.], starts as a series motor and runs synchronously as a repulsion motor with two fixed poiuts on the armature short-circuited. The Figure shows two machines 14, 15 having points situated 120‹ apart on one armature respectively connected to similar points on the other armature through leads 21 - - 23 and a switch 13. A switch 16 serves to short-circuit the brushes after starting, and another switch 12 short-circuits fixed points on each armature. In the preferred method of starting, the switches 16 and 12 are opened, switch 13 closed and switch 20 is closed in its lower position. The field windings are thus connected across the terminals of the alternator A; the armatures will not rotate but they may vibrate until they occupy the same relative position. Switch 20 is then closed in its upper position and both machines start and accelerate in step with each other. When the proper speed is attained, switches 16 and 12 are closed, and switch 13 may be opened. In a modification, the brushes . are not short-circuited at synchronous speed. The invention is particularly applicable in motion-picture recording or reproducing systems where one motor drives the sound record and the other the picture record.
Improvements in building elements or related elements and related methods
Номер патента: TR200100193T2. Автор: Ralph Ryder George. Владелец: Interlock Holdings Pty. Ltd.. Дата публикации: 2001-06-21.