Keyboard switch assembly having one piece plural pushbutton actuator and resilient mounting structure for plural cantilever beam contacts

Claim 1

A data entry keyboard system, comprising: a. a base member of insulating material having deposited thereon a plurality of spaced, first electrical contacts arranged in two spaced, parallel rows, and a second electrical contact positioned at an end of and between the two rows, said first and second contacts adapted for connection to electrical circuits; b. an electrically conductive and resilient contact strip having an elongated central bar with depending legs at either end and cantilever beams spaced along either side of and laterally extending from the central bar, said legs being fixed to the base member with one leg in engagement with the second electrical contact and with the central bar and cantilever beams spaced above the plurality of first electrical contacts with the ends of the beam being in alignment therewith, and further said central bar having a plurality of apertures spaced therealong; and c. a single molded sheet of resilient material positioned over the contact strip and fastened to the base member at the edges thereof to define a cavity containing the contact strip, said molded sheet having on its upper surface a plurality of raised portions forming keys with a molded convex perimeter around each key and positioned intermediate the surface of the key and surface of the molded sheet, said convex perimeter biasing the key away from the base member, and a plurality of depending studs each positioned under a key and in alignment with the ends of the cantilever beams so that as a key is depressed the stud pushes the end of the beam into contact with the first electrical contact positioned therebelow so that an electrical circuit may be completed between the first electrical contact and the second electrical contact, further said molded sheet having depending therefrom a plurality of retaining means adapted to be received in the apertures so as to attach the central bar to the molded sheet, said retaining means having a resiliently deformable nose of greater diameter than the aperture and an annular groove behind the nose to receive the wall defining the aperture.