| 摘要 |
<p>A microswitch comprises two pairs of fixed contacts (13) each pair being bridged by a respective bridge contact (11). The bridge contacts are axially biassed apart on the carrier (3) which is axially drivable between a rest position wherein one contact pair is bridged and the other open and an activated position wherein the contact state, are reversed. The carrier (3) is driven by an axially aligned push button (4) biassed from the carrier by a first coil spring (5) with the carrier being biassed into its rest position by a second coaxial coil spring (8). As the pushbutton is depressed a shoulder on the carrier (3) abuts a housing shoulder preventing axial movement of the carrier and the first coil spring thus compresses. Towards the end of its movement a ramp (42) on the pushbutton engates a ramp surface (3g) on the carrier sliding it off the housing shoulder. The stored energy in the first coil spring thus rapidly drives the carrier into its activated position, assisted by an overcentre apring (6) acting on the carrier. On release of the pushbutton' the second coil spring returns the carrier to its rest position.</p> |
