Patent ID: 8258901

Claim:
An energy-saving electromagnetic switching device comprising: a housing, and an electromagnetic assembly and a movable magnetic pole within the housing, the movable magnetic pole connected with a resilience means which engages with the movable magnetic pole to control the electromagnetic switching device switched on and off; wherein at least one locking assembly is set between the movable magnetic pole and the housing; via which the electromagnetic switching device can automatically and repeatably change from an on-state to an off-state if the electromagnetic assembly is momentarily energized; the locking assembly comprises a locking block, a locking clip and a flexible member; the locking block defines a stepwise center groove at a side face towards the locking clip; an outside face of the locking clip abuts against the flexible member, and under a prevention from the flexible member, one end of the locking clip is received in the center groove; a stopping portion projects generally at center of the groove; the center groove comprises a guiding groove section, limiting groove section, unlocking groove section, and returning groove section, which are successively associated together and surround the stopping portion; whereby, when the electromagnetic switching device is desired to switch on, the locking clip slides from the guiding groove section to the limiting groove section, once the electromagnetic switching device is de-energized, the locking clip slides to the unlocking groove section and is caught in the stopping portion under a resilience force of the resilience means; and when the electromagnetic switching device is desired to change from on-state to off-state the locking clip leaves the stopping portion and slides from the unlocking groove section to the returning groove section, once the electromagnetic switching device is de-energized, the locking clip slides from the returning groove section and to the guiding groove section under a resilience force of the resilience means.