GB395069A - Improvements in or relating to electromagnetic switches or circuit breakers - Google Patents

Abstract

395,069. Electromagnetic switches; automatic circuit breakers. ALLGEMEINE ELEKTRICIT€TS-GES., 2, Friedrich Karl-Ufer, Berlin. Feb. 16, 1932, No. 4621. Convention date, Feb. 18, 1931. [Class 38 (v).] Springs, arrangement of.-An electromagnetic excess-current switch has a contact lever 7 which is moved in the opening direction as the result of an impact on it of an armature 2 which is moved magnetically on excess current and just previously, or simultaneously, actuates mechanism which acts to obstruct the contact lever 7 on its return movement (in the closing direction) and to hold it fast in the open position. On the attainment of a given load current, a magnet 5 overcomes the action of a spring 29 and holding-magnet 3, which is saturated at the nominal current, to attract the armature 2 which, in its movement, strikes the contact 7 and rotates it counterclockwise about its pivot 11, thereby opening the circuit and tensioning a spring 17. Almost simultaneously, a lever 14 is rotated about the pivot 11 to rotate a latch arm 13 about its pivot 23, thereby releasing the actuating lever 26 which is moved clockwise by the tensioned spring 17. A lever 15 pivoted to the handle 26 at 24 is provided with a stop 18, which engages a roller 20 on the contact-lever 7 and prevents the latter from being restored to the closed position by the spring 17. A further stop 19 on the lever 15 serves as a " half-open " stop in case the impact is insufficient to rotate the lever 14. To reclose, the lever 26 is moved to the left pulling with it the levers 15, 7, and when the latter is in the closed position, the stop 18 leaves the roller 20 and the spring 17 is further tensioned until the handle 26 is latched at 13, 27. The lock 13, 27 may be released by thermal or electromagnetic means and the lever 26 may be in two normally-connected parts forming a free-handle arrangement.