A device for mutual locking of two switches has two tappets (5) which can move in the counter direction by a forced
coupling connection, when the switch is on, one
tappet is pushed to an opening position and the other one
tappet is pushed to a locking position. In order to implementing free-maintenance , each
tappet is provided with teeth bars (9) respectively with gears (10), radial levers (7) are respectively arranged on the gear and can overcome the deflecting of a pressure spring, the levers are connected by a joint lever (6), stop levers (11) are rotatingly arranged on each gear, the stop levers are respectively butted against on fixed stop parts (14), driven parts (15) are arranged fixedly and are respectively butted against on the stop surfaces of the stop levers, when one tappet is pushed to the opening position, the stop levers can be kept in the position, the other one tappet is pushed to the stop parts, and the driven parts can enable the stop levers to overcome the deflecting of a pulling force spring, wherein, the levers can overcome the other one deflecting of the pressure spring by the stop parts.