| 摘要 |
<p>1,272,165. Mechanical switches. SANDERS ASSOCIATES Inc. 8 Sept., 1970 [24 Nov., 1969], No. 43038/70. Heading H1N. A keyboard or switchboard comprises a base 24, a first layer of conductive material 20 a second layer 18 of spongy material with holes 22, and a third layer 14 comprising a sheet of flexible insulating material with conductive pads 16 in registration with the holes 22. A terminal (32, Fig. 1) is connected to each pad 16. A mask 12 with bevelled holes 26 may be placed over the flexible sheet to complete the keyboard. Key symbols 28 are etched or printed on the flexible sheet, but as an alternative, plastics key buttons (19, Fig. 3) may be adhered to the upper surface of the flexible sheet. As an alternative (Fig. 3) a sheet of conductive material may be used as the flexible sheet, the conductive pads being mounted on the base.</p> |
