| 摘要 |
A rubber dome switch assembly has a first contamination resistant sheet which overlies a circuit board upon which are switch footprints. The first sheet is apertured to expose the switch footprints and a second contamination resistant sheet overlies the first sheet and has switch closure pads on the underside thereof, each of which is adapted to bear against the corresponding switch footprint to close the switch. A third sheet is adapted to overlie the second sheet and has switch buttons formed thereon each adapted to bear against the second sheet to force the closure pad into contact with the corresponding switch footprint. A faceplate member overlies the third sheet. Pins are provided for aligning the several sheets, all of which are separable from each other, and bolts or spring clips are provided for clamping and holding the several elements together. To indicate switch button closure, an indicator such as a light-emitting diode, is associated with a respective switch button, and is aligned with a light pipe extending through the sheets, which is viewable through an aperture in the faceplate member. Alternatively, the indicator can be viewable through transparent portions of the first and second sheets, that are aligned with apertures in the third sheet and faceplate member.
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