Abstract: A calculator type keyboard includes push-button switch 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 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. Although 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.

Abstract: An ultrasonic wave transmitter employs a resonant rod to generate an ultrasonic wave in response to the striking of an end thereof by means of a striking member. A striking member support employed for controlling the movement of the striking member relative to the end of the rod is selectively positioned in contact with the end of the rod to provide for damping thereof following each striking.