Mitsubishi Denki Kabushiki Kaisha

Shigeharu Otsuka

Hiroyuki Okado

Yuji Mizuno

Masayuki Yoshida

Yuji Sako

Teijiro Mori

Shizutaka Nishizako

Shigeru Masuda

Masahiro Kakizoe

Tomoharu Hasegawa

Masahisa Kobukuro

Fumio Matsumoto

Switch

An electromagnetic contactor having normally open and normally closed contact pairs 22, 26 includes a movable crossbar 12 having apertures 14 with sloping guide surface 18', 18' for guiding movable contact members 16 disposed in the apertures. These sloping surfaces serve to jam the crossbar against the base 10 of the contactor when the crossbar is moved in a direction to open fused contact pairs, to thereby prevent the normally open and normally closed contact pairs from being closed at the same time.

Electromagnetic contactor

An electromagnetic contactor having normally open and normally closed contact pairs 22, 26 includes a movable crossbar 12 having apertures 14 each defining two guide surfaces 18a, 18b; 18c, 18d inclined at different angles for guiding spring biased movable contact members 16 disposed in the apertures. These inclined surfaces serve to jam the crossbar against the base 10 of the contactor when the crossbar is moved in a direction to open fused contact pairs during the initial spring decompression movement of the crossbar, to thereby prevent the normally open and normally closed contact pairs from being closed at the same time.

The disclosed electromagnetic contactor has a base including a lateral opening and an internal space, and two rails disposed at the bottom of the internal space. A U-shaped stationary iron core including two guides on both sides is assembled into a coil holder so that one leg of the 'U' is surrounded by an operating coil held by the coil holder. Then the coil holder is inserted into the internal space in the base through the lateral opening with the guides engaging the rails until it is removably positioned in the internal space.

An electromagnetic contact device performs on-off operations for opening and closing an electrical path, without causing the hunting phenomenon between the two contact points in the device not only during closure of a fixed contact point and a movable contact point therein, but also when a voltage to be applied to an operating coil has lowered. An operating coil generates a predetermined energizing force in combination with a fixed iron core, a starting circuit rectifies a large capacity electric current from an AC power source when attracting a movable iron core and supplies the rectified current to the operating coil. A holding circuit supplies the large capacity current from the AC power source to the operating coil through means of converting the large capacity current to a small capacity current at the time of holding the movable iron core. A change-over switch changes the energizing current supply source for the operating coil from the starting circuit to the holding circuit, the change-over switch having a hysteresis characteristic such that it performs its off-operation after closure of both contact points when the main circuit is closed, and performs its on-operation after separation of both contact points when the voltage to be applied to the operating coil has been lowered.

Electromagnetic contact device

Growing community of inventors

Gifu, Japan

Shigeharu Otsuka