Pocket electronic calculator keyboard - with moulded flexible plastic cover whereon keys are embossed and multiple inner click spring common contact

Abstract

Abstract The keys are of transparent silicone resin and the flexible cover plate, esp. reinforced with coloured fabric has flexible silicone resin pressure pads below the keys on its under side. Its rectangular mounting frame has locating dowels on its under side for firstly a common contact plate of annealed beryllium bronze, esp. gold plated before annealing and this plate has individual curved cross section, clich spring contacts in cut outs below the keys, which require a predetermined threshold pressure for deflection through apertures in an insulator plate to contact individual printed circuit contact islands on the bottom plate of the unit.

Inventors

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