Calculator keyboard switch with disc spring contact and printed circuit board
USRE29440E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1976 |
| Grant date | Oct 11, 1977 |
| Priority date | — |
| Expiry date | Mar 9, 1996 |
Classification
- Technology area (CPC —)General
Abstract
A keyboard switch assembly including a printed circuit board having four switch terminals on one side of the board, three of the terminals being arranged in a triangle and the fourth disposed within the triangle. Conductors on the one side of the board are respectively joined to the interior terminal and at least one of the three terminals. A conductive, generally triangular, snap-acting dome switch member is provided having arcuate apices, projections being respectively formed from the apices and respectively engaging the three terminals thereby spacing the periphery of the switch element from the one surface of the printed circuit board and the conductors thereon, at least the conductor connected to the interior terminal extending under the dome. The switch element has a fourth projection formed from the interior of the dome adjacent the center thereof which is in registry with the interior terminal and engages that terminal when the dome is deflected thereby completing an electrical circuit between the three terminals and the interior terminal. A layer of insulating material covers the conductors exclusive of the terminals. A sheet of insulating material covers the insulating la…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.