Automatic shutoff mechanism for magnetic tape recording and reproducing apparatus

An apparatus operable in a plurality of modes, including play, stop, and rewind modes, for recording and/or reproducing signals on a magnetic tape extending between first and second reels to which the ends of the tape are secured and on which the tape is wound, said apparatus comprising:

• first and second rotatable reel support members for rotational coupling with the first and second reels respectively;
• drive means including an electric motor;
• drive control means including a switch having a normal inoperative condition and being actuable to an operative condition for energizing said motor and thereby effecting operation of said drive means;
• manually operable actuating means movable from a normal inoperative position to an operative position for actuating said switch means to said operative condition thereof;
• latch means for releasably holding said actuating means in said operative position thereof;
• transmission means connected to said drive means and responsive to said drive control means for driving a selected one of said reel support members to rotate in the direction for winding tape on the reel respectively coupled therewith and for permitting continued operation of said drive means when rotation of said reel support members is arrested upon the full unwinding of the tape from the other of said reels;
• shutoff means including latch release means displaceable to a predetermined extent for releasing said latch means;
• latch release operating means movable between a first inoperative position and a second operative position in operative driven engagement with said drive means to be driven by said drive means for displacing said latch release means to said predetermined extent only when the rotation of said reel support members is arrested during the continued operation of said drive means, and means for selectively moving said latch release operating means from its inoperative position to its operative position including a lever pivotally mounted in said apparatus and having one end positioned adjacent said latch release operating means;
• means for normally biasing said one end of said lever to a first position against said latch release operating means at which the latter is held in its operative position;
• means driven by said drive means for oscillating said lever, against the bias of said biasing means, between said first position thereof and a second position wherein said one end of the lever is out of engagement with said latch release operating means;
• and stop means operatively engaged with one of said reel support members for limiting oscillation of said lever, during rotation of said one reel support member, to movement between said second position of the lever and an intermediate position at which said one end of the lever is adjacent to but out of engagement with said latch release operating means and for releasing said lever for movement to its first position by said biasing means when rotation of said one reel support member is arrested thereby to move said latch release operating means to its second position for displacing said latch release means to said predetermined extent.