| 摘要 |
A keyboard has domed switch elements and complementary switch contacts which are mounted in an inexpensive housing formed of a very thin, flexible, electrically insulating sheet material. The housing is shaped by vacuum-forming to have flexible webs of the sheet material extending between relatively more rigid cup-shaped embossments formed in the sheet material. The webs and cupped embossments engage the domed switch elements and complementary contacts and normally hold the switch elements in open circuit positions relative to the contacts. However, flexing of the housing webs permits the domed switch elements to be selectively deflected to closed circuit positions engaging the contacts. Additional rigid embossments are formed in the thin housing material and are located over the domed elements to assist in deflecting the elements to their closed circuit positions. A keytop is also shaped from a thin sheet material by vacuum-forming to have flexible webs which extend between key embossments. The key top embossments are marked with suitable indicia and are nested over and rested on the additional rigid embossments of the housing which are formed over the domed elements, whereby pressure applied to a key top embossment deflects a corresponding domed switch element to its closed circuit position within the housing.
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