Patent ID: 8274347

Claim:
An electromagnetic switch comprising: stationary electrodes fixed to an outer case; a movable contact arm contactable with or separable from the stationary electrodes; a shaft having an upper end fixed to the movable contact arm; a movable core attached to a lower portion of the shaft; a stationary core configured to wrap the shaft at a position facing the movable core; an excitation winding that is wound on the movable core and the stationary core; an upper yoke and a lower yoke configured to shield the excitation winding to form a flow path of a magnetic flux with the movable core and the stationary core; an arc protection member located between the movable contact arm and the upper yoke to shield the shaft for protection; and a wipe spring located between the movable contact arm and the upper yoke to maintain contact pressure between the movable contact arm and the stationary electrodes, wherein the arc protection member is installed to wrap the wipe spring; a first arc protection shield contacting a lower surface of the movable contact arm; and a second arc protection shield detachably coupled to the first arc protection shield and configured to shield an upper surface of the upper yoke; and an auxiliary spring located within the arc protection member and configured to press the arc protection member toward the movable contact arm.