Abstract: A dust preventing device for an electromagnetic contactor prevents foreign matters accumulated on a foreign matter preventing wall from slipping off the wall due to vibrations of electromagnetic contactor. In a case where an arc extinguishing chamber cover is disposed to cover a fixed contact and a movable contact, and includes a foreign matter preventing wall provided under a gas discharging opening formed on the cover, the foreign matter preventing wall is formed with ribs provided therearound in a shape of an embankment. Therefore, foreign matters having entered through the gas discharging opening can be positively trapped in a hollow portion surrounded by ribs, so that the foreign matters do not fall into the electromagnetic contactor from the foreign matter preventing wall due to vibrations of the contactor.

Abstract: A terminal device for connecting an end portion of an exciting coil to an external conductor, said exciting coil being formed on a bobbin and operating, for example, a contact of an electromagnetic contactor. The terminal device includes a terminal base mounted on the bobbin, an electrically conductive terminal plate, and means for mounting the terminal plate to the terminal base such that a force exerted on the terminal plate at its end connected to the external conductor is not transmitted to the end portion of the exciting coil.

Abstract: A contact device includes a housing, a fixed contact, and a moving contact attached to a support frame, the support frame and moving contact movable within the housing perpendicular to the fixed contact. A stopping arm projects from the support frame to restrict movement of the support frame within the housing.

Abstract: An electromagnetic contactor includes an arc-extinction cover that prevents an electric arc generated during the disconnection of a fixed contact and a movable contact for bridging adjacent fixed contacts. A removable terminal cover serves to cover terminal screws attached to the fixed contacts. The arc-extinction cover and the terminal cover are separate from the contactor body and are attachable and detachable.