Control system for tape unit

Claim 1

IN A MAGNETIC TAPE FEEDING MACHINE HAVING TWO VARIABLE SPEED REVERSIBLE ELECTRIC REEL MOTORS FOR DRIVING TAPE SUPPLY AND TAKE-UP REELS, A FIRST AND A SECOND VOLTAGE SOURCE, A SYSTEM FOR SERVO-REGULATION OF SAID REEL MOTORS WITH TWO FIRST LIGHT-RESPONSIVE DEVICES LOCATED TO SURVEY THE POSITIONS OF TWO BIGHTS OF TAPE IN TWO AIR DEPRESSION COLUMNS DURING RECORDING AND REPRODUCING OPERATIONS AND TWO TAPE DRIVE CAPSTANS, FURTHER CONTROL MEANS INCLUDING FIRST RELAY-OPERATED SWITCHING MEANS WHICH WHEN ENERGIZED IN ONE POSITION CONNECTS SAID REEL MOTORS WITH SAID FIRST VOLTAGE SOURCE WHEREBY SAID REEL MOTORS SLOWLY DRIVE SAID REELS IN A DIRECTION TO WIND TAPE ON BOTH OF SAID TAPE REELS AND WHICH WHEN ENGAGED IN ANOTHER POSITION CONNECTS SAID REEL MOTORS WITH SAID FIRST VOLTAGE SOURCE WHEREBY SAID REEL MOTORS DRIVE SAID REELS IN A DIRECTION TO UNWIND TAPE FROM BOTH OF SAID TAPE REELS; SECOND RELAY-OPERATED SWITCHING MEANS WHICH WHEN ENERGIZED CONNECTS SAID REEL MOTORS TO SAID SECOND VOLTAGE SOURCE THROUGH SAID SERVO-REGULATION SYSTEM, SAID SERVO-RESPONSIVE SYSTEM BEING CONTROLLED BY SAID FIRST LIGHT-RESPONSIVE DEVICES; A HEAD UNIT MOUNTED TO BE MOVED B ETWEEN A FIRST AND A SECOND POSITION; AN ELECTRO-MAGNETIC ACTUATOR MECHANICALLY COUPLED TO SAID HEAD UNIT FOR NORMALLY MAINTAINING SAID HEAD UNIT IN SAID FIRST POSITION OUT OF THE TAPE PATH; AN ELECTRO-MAGNETIC ACTUATOR RELAY MEANS FOR CONTROLLING THE OPERATION OF SAID ELECTRO-MAGNETIC ACTUATOR, SAID ELECTRO-MAGNETIC ACTUATOR BEING EXCITED BY SAID ELECTRO-MAGNETIC ACTUATOR RELAY MEANS CONCURRENTLY WITH THE OPERATION OF SAID SECOND RELAY-OPERATED SWITCHING MEANS FOR CAUSING SAID ELECTRO-MAGNETIC ACTUATOR TO MAINTAIN SAID HEAD UNIT IN ITS SECOND POSITION FOR TRANSDUCING; CONTROL RELAY MEANS ADAPTED TO BE MANUALLY OPERATED AND WHEREBY ONE OPERATION WILL RENDER SAID SECOND RELAY-OPERATED SWITCHING MEANS INOPERATIVE AND RENDER OPERATIVE SAID FIRST RELAY-OPERATED SWITCHING AND ENERGIZE SAID ELECTRO-MAGNETIC ACTUATOR RELAY MEANS, AND ANOTHER OPERATION WILL RENDER SAID SECOND RELAY OPERATED SWITCHING MEANS OPERATIVE AND RENDER INOPERATIVE SAID FIRST RELAY-OPERATED SWITCHING MEANS AND DE-ENERGIZE SAID ELECTRO-MAGNETIC ACTUATOR RELAY MEANS THEREBY CAUSING SAID HEAD UNIT TO BE RETURNED TO THE SECOND POSITION FOR TRANSDUCING; A SECOND LIGHT-RESPONSIVE DEVICE LOCATED SUBSTANTIALLY ALONG THE TAPE PATH BETWEEN SAID TAPE REELS AND SAID TAPE DRIVE CAPSTANS FOR SENSING THE PRESENCE OF A BIGHT OF TAPE; AND A THIRD RELAY-OPERATED SWITCHING MEANS CONTROLLED BY SAID SECOND LIGHT-RESPONSIVE DEVICE TO DE-ENERGIZE SAID FIRST RELAY-OPERATED SWITCHING MEANS WHEN THE BIGHT OF TAPE GOES BEYOND SAID SECOND LIGHT-RESPONSIVE DEVICE.