ELECTRIC CIRCUIT SWITCHING DEVICE Russian patent published in 2007 - IPC H01H9/26 

FIELD: electrical engineering.

SUBSTANCE: proposed device that can be used to control dual-speed electric motors as well as to connect power loads in series with power supply or to function as phase-sequence change-over apparatus has two vacuum chambers. Second-chamber movable contact is mechanically joined with lever so that when first-chamber contacts are open, those of second vacuum chamber are closed and vice versa, when first-chamber contacts are closed, second-chamber ones are open. Device incorporated provision for reliable interlocking of its contacts to prevent throwing of two loads onto full voltage at a time.

EFFECT: enhanced reliability and minimized time interval between on-operation of one load and off-operations of other load.

5 cl, 3 dwg