GB1258166A - - Google Patents

Abstract

1,258,166. Substation apparatus. ANSAFONE Ltd. 16 July, 1970 [11 Aug., 1969], No. 40112/69. Heading H4K. A telephone answering device includes means to respond to a call, on a first telephone line, means to dial out to a further subscriber over a second line, means for accepting and holding the incoming call and means for detecting the disconnection of the caller and for releasing both lines in response thereto. As shown if a call arrives on a line L1 a ringing detector RD1 responds enabling an automic dialler AD which dials out over a line termination unit LTU2 and a line L2 to another subscriber to whom the call is to be diverted. A detector D responds to the detection of "ringing" tone, "busy" tone or "number unobtainable" tone to initiate operation of a line termination unit LTU1 which accepts and holds the call on line L1 and couples the line L1 to the line L2 via the termination units. When the caller hangs up an end of call detector DD responds disabling both line termination units and thus releasing both lines. If an incoming call arrives over the line L2 instead of L1 a detector RD2 responds operating a line changeover switch LCO to interchange the connections between the lines L 1 , L 2 and the rest of the equipment.