Press contact key switch for telephones - uses spring action metal tongues with gold plated contacts

摘要

The action of the switch is based on the elastic properties of metal tongues (1) in which thin blisters (4) are stamped. The desing is suitable for keyboard applications particularly for telephones. Several tongues formed in a single strip are riveted (8) at one end (20) of the tongue which results in its downward bending into a recess (11) in an action which is made more positive by the springy inversion of the blister. Contact is made by the tongue onto gold-plated studs (15) which are riveted to printed circuit tracks (14). A rapid breaking of the contact ensues from releasing the pressure (P).