Special service routing

Claim 1

In an automatic telephone system including at least first and second groups of line circuits, each group including a plurality of subscriber line circuits and at least one service line circuit, said subscriber line circuits being identified by individual multi-digit members and said service line circuits being identified by individual multi-digit numbers having a common first digit, class of service designating means for providing a class of service indication only in connection with said subscriber line circuits, connection means for interconnecting telephone lines, and common control means responsive to multi-digit signals received from a calling line circuit for actuating said connecting means to interconnect said calling line circuit and a called line circuit designated by said multi-digit signals, a special routing arrangement for single digit line access to service line circuits comprising routing means responsive to detection of a signal representing said common first digit from a calling line circuit for applying a class of service requesting signal to said class of service designating means through said calling circuit, said class of service designating means including digit generating means responsive to said class of service requesting signal for generating a second digit signal specifically identifying a single service line circuit in the same group as the calling line circuit and applying said second digit signal to said common control means through said routing means, and number forming means for generating additional digit signals forming with said signals designating said first and second digits the multi-digit signals representing the number of said single service line circuit.