Telephone Rotary Dial Mechanism

Описание: The back side and innards of a rotary dial mechanism from a 1978 telephone. A clever arrangement of electric contacts and levers creates the "clicking" signals (pulse dialing) that go to the telephone exchange. Inside (not seen here) is a gear with a vertical spring that rotates the dial back to its original position, and the rotating axis with the brass extensions helps to control the rotation speed by creating more friction (in way of centrifugal force) as the speed gets higher.