Abstract: A keyboard assembly including a plurality of key operated switches, each of which includes a dome associated with contacts on a printed circuit board which when triggered upon being subjected to a triggering force closes the switch and upon being released opens the switch and a keycap or push button for operating the dome and a transmission system for transmitting a force from the keycap to the dome which includes an actuator extending from the keycap and a conically shaped helical spring between the actuator and the dome with the small end of the spring in working engagement with the dome. The underside of the dome is vented to the atmosphere through a vent in the printed circuit board which is sealed against contamination of dust by a perforated adhesive backed plastic film or sheet over the underside of the printed circuit board.

Abstract: A keyboard elastomeric cover which includes buttons or keys having changeable legends, sealing means for sealing the cover to a switch subassembly and alignment bosses or posts coacting with the subassembly to maintain proper alignment between the buttons or keys and the switches on the subassembly.

Abstract: An apparatus for illuminating keyboard or individual switches in which a conventional plastic contact actuator member is fabricated of translucent material so that it may function additionally as a conductor and diffuser of light. A lamp source is positioned in the center of a conventional dome-printed circuit switch within holes provided in the metal contact domes and the substrate of the switch. The actuator includes a cylindrical lower hood portion having a recess in the center thereof permitting it to receive the lamp source upon switch actuation.

Abstract: An elastomeric boot for covering a keyboard subassembly and having a lip sealing means extending over and under the assembly to prevent entry of contaminants.

Abstract: A switching assembly includes an insulative substrate upon which is carried a plurality of conductive paths respective portions of which are selectively bridged upon depression of a resilient conductive contact element. That contact element is generally in the shape of a dome and has a central region of substantially planar conformation from which the remainder of the dome slants integrally downward and outward to a lower marginal rim portion. The dome-shaped element is disposed adjacent to the substrate with at least a portion of its rim portion electrically and physically contacting one of the portions of one of the paths. The central region is generally in registry over another of the portions in another of the paths so as to enable connection between the central region and that other portion upon depression of the central region.

Abstract: A keyboard assembly includes an insulative substrate upon which are carried a plurality of conductive paths. Respective portions of the paths are selectively bridged upon depression of a dome-shaped conductive resilient contact element. A pair of space-opposed regions of the dome's marginal portion are deformed downwardly away from its apex so as to constitute a pair of space-opposed feet. The feet have a complex shape which leads to high lifetime of the dome. Preferably, the feet rest on corresponding conductive pads, and the pad pairs for adjacent domes may be differently oriented so as better to accommodate the passage of leads between those domes. Leads on the substrate passing beneath dome edges desirably are depressed into the substrate. Overlying the domes in a completed assembly is a layer of deflectable insulating material that is adhesively affixed to the substrate and to the domes; the latter includes an aperture in registry with each dome but of a diameter smaller than the width of such dome.

Abstract: A keyboard assembly includes an insulative substrate upon which are carried a plurality of conductive paths. Respective portions of the paths are selectively bridged upon depression of a dome-shaped conductive resilient contact element. A pair of space-opposed regions of the dome's marginal portion are deformed downwardly away from its apex so as to constitute a pair of space-opposed feet. The feet have a complex shape which leads to high lifetime of the dome. Preferably, the feet rest on corresponding conductive pads, and the pad pairs for adjacent domes may be differently oriented so as better to accommodate the passage of leads between those domes. Leads on the substrate passing beneath dome edges desirably are depressed into the substrate. Overlying the domes in a completed assembly is a layer of deflectable insulating material that is adhesively affixed to the substrate and to the domes; the latter includes an aperture in registry with each dome but of a diameter smaller than the width of such dome.