Patent ID: 7046774

Claim:
An intercom apparatus comprising: at least one entrance substation which is disposed at an entrance; a plurality of intercom master stations which are disposed in residential rooms and called from said entrance substation through a main line to intercommunicate with said entrance substation bilaterally, each of said plurality of intercom master stations comprising a mounting bracket; a plurality of terminal units, each of said terminal units being received in a mounting bracket and being removable therefrom as needed without changing a wire connection within either the intercom master station or the terminal unit, each of said terminal units having terminals for connecting wiring between the plurality of intercom master stations by station-to-station spanning wiring to form said main line and a terminal board for mounting said terminals and establishing an electrical connection of said main line by said station-to-station spanning wiring; and wherein each of said terminal units has a projection which is inserted into a guide groove in the mounting bracket of said intercom master station, and each of said intercom master stations has locking parts for holding said terminal unit to the intercom master station by engaging an end face of an external chassis of said terminal unit, which covers said terminals and said terminal board, upon insertion and subsequent movement orthogonal to the direction of insertion of said terminal unit.