Electronic telephones with cooperative interaction between a master set

Abstract

Automated telephones with electronic circuits for outputting dial digit sequences respectively corresponding to different ones of a plurality of user's switches when each switch is momentarily actuated. The circuits permit speed dialing of (i) directory numbers, (ii) tandem sequences for accessing outside centers and specific line numbers, and (iii) access or feature codes. The apparatus is characterized especially by devices to create automatically loop breaks to simulate either a hook flash or a re-seize on-hook condition in certain circumstances and despite the fact that the telephone remains off-hook. By simple wire connections between a master or 'secretary's ' telephone and each of the members' phone sets within a limited group, intelligence signals are interchanged to provide 'key line group' action without an elaborate, separate 'control box' and even though each telephone of the group is served by the central system only via its own two-wire line.