Automatic telephone answering system with variable speed drive control

Claim 1

An automatic telephone answering system employing a multichannel, endless magnetic tape traveling along a path and having one channel for the playback of a previously recorded answer to callers and a plurality of channels for the recording of messages from callers, comprising: a variable speed tape drive means for driving said tape and operatively connected thereto, said tape drive means comprised of a variable speed motor; first detection means for detecting each completion by said endless magnetic tape of a complete cycle of travel around its first path, said first detection means comprised of a detector operatively positioned adjacent the path of said endless magnetic tape for detecting completion of each cycle of travel of said tape, a first detection circuit coupled to said detector, said first detection circuit normally producing an output, said output terminating in respnse to a detection by said detector, and a first JK flip-flop coupled to said first detection circuit and gated thereby; a speed control means operatively connected to said first detection means and said tape drive means, said speed control means being responsive to said first detection means for changing the speed at which said tape drive means said endless magnetic tape, for causing said endless magnetic tape to be driven more slowly during recording of messages than during playback of the previously recorded answer, said speed control means comprised of a changeover circuit coupled to said J-K flip-flop, said changeover circuit including three relays, a first relay being coupled to said variable speed motor for switching said motor from high speed to low speed and normally positioned for high speed operation, a second relay being coupled to recording and reproducing heads and normally to said reproducing head and adapted for switching to said recording head upon activation of said second relay upon completion of a first cycle of tape travel, and a third relay coupled to a warning circuit; second detection means connected to a telephone for detecting an incoming telephone call and producing an output indicative thereof, said second detection means including a second detecting circuit coupled to the telephone line and producing an output signal in response to an incoming telephone call, a first differentiating circuit coupled to said second detecting circuit and producing an output in response to the output signal from said first detecting circuit, an RS flip-flop having inputs and and an output, one of said inputs coupled to said first differentiating circuit, a second differentiating circuit coupled between an input of said RS flip-flop and the output of said JK flip-flop, whereby output from said first differentiation circuit turns said RS flip-flop on; power supply means connected to said variable speed tape drive means and said second detection means for supplying power to said tape drive means in response to an incoming call, said tape drive means being initially in a fast speed mode of operation; and speed changing means connected to said second detection means, said variable speed tape drive means and said power supply means for changing the speed of said tape drive means to a slow speed mode of operation in response to the detection of a first complete tape cycle by said detection means, and for returning said tape drive means to the fast speed mode of operation and for deactivating said power supply means in response to the detection of a second complete tape cycle by said detection means, said speed changing means comprised of a third differentiating circuit coupled to said second differentiating circuit, a monostable multivibrator coupled to said third differentiating circuit, a relay coupled to said monostable multivibrator, a solenoid couplEd to said relay and to said variable speed control means, a switch coupled to said solenoid and a pulley coupled to said switch, said pulley adapted to shift said recording head to a next track on the tape.