| 摘要 |
This invention includes a switch using two flexible domes positioned to engage the underside of a lever bar. The lever bar includes a top substantially flat surface with the exception of two spaced apart ramped nubs. A keycap is positioned over the lever bar for pivotal movement in a housing carrying the same. The keycap includes two spaced apart downwardly extending legs for engaging the top surface of the lever bar. The keycap is movable from a first position wherein the two downwardly extending legs straddle the outside of the two ramped nubs and wherein both flexible domes are fully extended and not collapsed. The elongated keycap may be depressed on a first end causing a first leg of the keycap to force the lever bar downward collapsing a first dome and closing a circuit underneath the dome. As the keycap is depressed the first leg moves over a first ramped nub and is latched in a position between the two ramped nubs. In this second position the second dome is fully extended. The keycap may be moved to a third position by depressing a second end of the keycap forcing the second leg to press downward on the lever bar causing the second dome to collapse and close a circuit underneath the same. As the second end of the keycap is depressed, the second leg moves over the ramped surface of the second nub and is latched in a position between the two nubs. In this third position, the first dome is and fully extended and not collapsed.
|
