GB458295A - Improvements relating to partly electro-magnetic switches - Google Patents

Abstract

458,295. Self - contained supply systems. MATHER & PLATT, Ltd., and ALVEY, G. B., Park Works, Newton Heath, Manchester. Jan. 6, 1936, No. 426. [Classes 35 and 38 (iv)] [See also Group XXXVII] Variable-speed generators, with ; exciting.- In a system employing a reversible generator, the polarity of which is reversed on reversal of the direction of rotation there is employed a two-way electric switch or contactor characterized by the fact that when the switch or contactor is moved to a final closed position in either direction, the means which give it a preliminary movement in the closing direction are moved clear of one another and so rendered inoperative. As shown in Fig. 2, the sector k is loosely pivoted at its upper end on a pin m and rests on the armature shaft n. When the shaft rotates in one or other direction the sector is rotated about the pin m until a contact pin secured to the sector engages one or other of a pair of contacts o. This completes the circuit of a solenoid, the core r of which supports the sector through links q which are then drawn up, forcing the pin j firmly against the contact o which is rotated against a spring p, Fig. 5. Thus, as shown, the electromagnet on operation draws the sector k away from the shaft to complete its movement. As employed in the train-lighting circuit shown in Fig. 1, the operation of the change-over switch i connects the field winding d to one or other of a pair of auxiliary brushes h or h<1>, the operating coil of the switch being connected directly across the main brushes a, a. In order to ensure that a voltage will be built up to operate the switch, a resistance v may be permanently connected across the brushes in series with the field d and regulating resistance e, as shown in Fig. 6.