Telephone receiver numerical push button dial - has printed circuit boards to which normal telephone connections can be made

摘要

The telephone push button dial has twelve buttons (17) arranged in four rows and three columns. It has a base (11) and a cover (13). The base having flaps (24, 24') placed below it and diametrically opposite to each other which are used for fixing the dial to the receiver. The surface of the cover (13) has holes formed in it into which the pushbuttons fit. Underneath the cover is a printed circuit board (18) having projecting elements (19) on it, which enclose an elastic device (21) having a projection (21'). The elements (19) form switch contacts for the push buttons (17). A second circuit board (27) is provided for the dial system electronic circuits.