Patent attributes
In an electrical contactor a first terminal (5) is connected to a pair of contacts (3, 4) on opposite faces of a fixed conductive member (2). A second terminal (6) is connected to a pair of movable arms (7, 8) of electrically conductive material carrying movable contacts (9, 10) at an end remote from the connection to the second terminal (6). The movable arms (7, 8) are arranged in aligned opposition to each other and such that their remote ends are on either side of the fixed member (2) with the movable contacts (9, 10) aligned with the fixed contacts (3, 4). The arrangement of the fixed member (2) and movable arms (7, 8) is such that when the contacts are closed current flowing through the movable arms produces a force that urges the movable arms towards each other thereby increasing the force between the fixed and movable contacts. In such a contactor overload currents cause the contact force to increase due to the attractive electromagnetic force produced between the arms (7, 8) by currents flowing in the same direction in the arms (7, 8).
