A contact arrangement of an electric switch, comprising a first stationary contact (110), a second stationary contact (112) and a movable contact (130) for making an electrical connection between the first (110) and second (112) stationary contacts, wherein the movable contact (130) is pivotally connected to the first stationary contact (110) by a pivotal connection for allowing the movable contact (130) to pivot with respect to the first stationary contact (110) about a pivoting axis (116, 135) such that in an open position of the switch, the movable contact (130) is disconnected from the second stationary contact (112), and in a closed position of the switch, the movable contact (130) is in contact with the second stationary contact (112). The movable contact (130) and the first stationary contact (110) are arranged in a first angle with respect to each other in the open position of the switch, and in a second angle with respect to each other in the closed position of the switch, and the second angle is greater than the first angle.

There is provided an electromagnetic contactor, electromagnetic contactor gas encapsulating method, and electromagnetic contactor manufacturing method at a low cost and with stable quality by simplifying a gas encapsulating step. The electromagnetic contactor includes a base plate (7) having an aperture hole, a tub-like arc extinguishing chamber (1), of which one end is opened, having a fixed terminal (2) and pipe (3) penetrating and fixed to a wall surface, and a bottomed tubular cap (8). An arc extinguishing chamber connection portion (6) is formed of the arc extinguishing chamber (1) and a first connection member (4) having a tube portion (4a) of which one end is in close contact with, and connected to, the opened end surface of the arc extinguishing chamber and a flange portion (4b), linked to the other end of the tube portion, that can be brought into close contact with the base plate. A cap connection portion (12) is formed of the cap (8) and a second connection member (5) having a tube portion (5a) of which one end is in close contact with, and connected to, the opened end surface of the cap and a flange portion (5b), linked to the other end of the tube portion, that can be brought into close contact with the base plate. The arc extinguishing chamber connection portion (6) and cap connection portion (12) are attached so as to be in communication via the aperture hole of the base plate (7).

The present invention provides a contact device capable of easily extinguishing an arc that is generated between a fixed contactor and a movable contactor when the contact device is in an open state, and an electromagnetic switch that uses this contact device. The contact device has: a pair of columnar fixed contactors (6a, 6b) which are fixed to a surface of an insulation container (4) while keeping a predetermined space therebetween and each have at least a tip end contact surface protruding into the insulation container; and a movable contactor (11) that is disposed so as to be capable of coming into contact with and separating from the pair of fixed contactors (6a, 6b). Surfaces of the pair of fixed contactors (6a, 6b) that face the movable contactor (11) are configured by annular peripheral walls (9) having concave parts (9a) at central parts thereof. An annular arc is formed between the annular peripheral walls (9) and the movable contactor (11) when the contact device is in an open state.

The present invention relates to an air circuit breaker, in which a recess is formed on one side or each of both sides of each contact plate provided in an insulating cage so as to reduce a contact area between a movable contactor and the contact plate when the movable contactor and the contact plate are brought into contact with each other, thereby preventing a contact portion between the movable contactor and the contact plate from being melted due to heat generation.