| 摘要 |
<p>4780 An electrical switch comprises a housing (1) carrying a first, fixed contact (3) and a second, movable contact (6) in the form of a resilient contact arm secured to the housing (1) at one end, and an actuator member (15) mounted on the housing (1) and operable to urge the resilient contact arm (6) from a first position out of engagement with the fixed contact (3) into a second position in engagement with the fixed contact (3). The resilient contact arm comprises a single inner limb (9) and two outer limbs (10, 11) one of which is engaged by the actuator member (15) and the other of which engages the fixed contact (3) on operation of the actuator member, at which, initially the whole resilient contact arm deflects by bending of the single inner limb (9) until the other outer limb (11) engages the fixed contact (3) whereafter the two outer limbs (10, 11) of the resilient contact arm are deflected towards each other thereby to increase the contact force between the other outer limb (11) and the fixed contact (3). The contact points (4, 25) of the fixed contact (3) and the other outer limb (11) of the resilient contact arm can be embedded in a body (24) of electrically insulating material. The housing (1) can be of one-piece construction, the actuator member (15) being retained in the housing (1) by a part of the second contact (6).</p> |
