Switching system for readily accessing the service line for test basic unit and the switching system for readily accessing the service line for test expansion unit

Claim 1

An electromechanical switching arrangement equipped for testing a plurality of two-wire telephone circuits existing between a plural number of subscriber stations and a plural number of telephone company two-wire lines to a central office, the arrangement comprising: an individual double pole single throw, normally closed switch connected at the subscriber premises in series between each of said plurality of two-wire telephone circuits, an individual double pole double throw switch with each normally open contact of each switch connected to one or the other line of a respective one of said two-wire lines of said plural number of telephone company two-wire lines, an individual normally closed contact of each double pole double throw switch connected to an individual switch arm terminal of a next adjacent of said double pole double throw switches, each individual normally closed contact of a last of said double pole double throw switches being connected to an individual terminal of a two terminal means for further connection, individual switch arm terminals of a first of said adjacent of said double pole double throw switches being connected to two terminals of a modular jack for connection to a standard telephone which is to be used for testing, a capacitor inserted in series with a tip line between said modular jack and said first double pole double throw switch, a normally closed single pole single throw switch connected in parallel with said capacitor, and a respective normal open switch connected in series between each said line between the modular jack and said first double pole double throw switch, and a system ground circuit.