| 摘要 |
<p>RCA 71357/71358 SWITCH MECHANISM FOR A CALCULATOR TYPE KEYBOARD A calculator type keyboard includes push-button switch contact mechanisms formed as integral parts of a conductive web. Each of the mechanisms includes support arms intersecting in a crisscross configuration only a portion of which is deformed in a dome-like contour. Contact blades extend from the intersection of the support arms and have ends coupled to adjacent support arms by bridge members. As the switch contact mechanism is depressed to various degrees, the supported contact blades make contact with respective binary code conductors, the dome-like contour deflects through a snap action position and finally the apex of the dome-like contour makes contact with a centrally located flag contact. While closure of the contact blades and code conductors is maintained, radial wiping movements of the contact blades across the surfaces of the code conductors occur.</p> |
