| 摘要 |
A switch for push-pull actuation comprises: a housing 102 having a recess 118 to receive a mounting portion of an elongate bushing 104 that has a neck portion protruding from the housing; and an elongate actuation shaft 106 mounted in the bushing. First and second bearings 114 are provided between the actuation shaft and the bushing. The first bearing is provided in the mounting portion of the bushing and the second bearing is provided in the neck portion of the bushing. The bearings can be spaced apart by a distance greater than 10mm or the cross section of the shaft; be at least 5mm long; made as a brass or ceramic sleeve; and be a push fit on the shaft and move with it. A spring 116 attached to the bushing and to the shaft can bias the shaft to a resting position from an actuated position where a paddle 110 engages one of two switches 112. Axial movement and rotation of the shaft can be limited by a paddle block 124 that moves in a recess 128 in housing 102. An indicating LED 134 can be mounted in an actuating cap 122 at the end of the shaft which has a passage for its wiring. The switch can ensure stability by constraining and minimising deflection and is intended for use with a tile for a mosaic mimic system. |
