| 摘要 |
A pushbutton dial has a cover, a back member and a circuit member assembled in a sandwich formation, the cover supporting a plurality of pushbuttons arranged in columns and rows. Longitudinal and transverse shafts are mounted between, the cover and back member, actuation of a pushbutton rotating a unique pair of longitudinal and transverse shafts. Frequency contacts are mounted on the back surface of the circuit member - usually a printed circuit board - and are actuated by pins passing through the back member and the circuit member one end of each pin in engagement with one set of frequency contacts and the other end of each pin in contact with a lever on one of the longitudinal shafts or one of the transverse shafts. The dial can also be provided with a new form of common switch comprising a series of cantilevered spring contacts mounted side by side and actuated by a cam member in a predetermined sequence.
|
