Cassette tape playout sensing, indication and protecting means

Claim 1

Cassette tape protective means comprising a cassette having a casing insertable into a cassette tape recorder; a magnetic tape in said casing engaged at opposite ends upon rotatable reels; a conductive trailer at one end of the tape; and a conductive leader at the other end of the tape, said leader and trailer being respectively engaged on rotatable reels in the casing, said casing having a wall with spaced openings for engagement by a tape drive capstan, for contact by an erase head, by a recording playback head, and by operative parts of an end-of-tape sensing circuit in the cassette recorder; said protective means further comprising an end-of-tape sensing circuit, said circuit comprising a pair of spaced wiper contacts disposed for insertion into one of said openings in the casing to contact the tape; a power supply; a relay connected in circuit with said wiper contacts and said power supply; and alarm means connected in circuit with the power supply and relay for actuation when said wiper contacts contact the conductive trailer and the conductive leader to indicate that an end of the tape is approaching one of said heads in the recorder; a motor operatively arranged to drive the tape between said reels, and another relay connected in circuit with said motor, power supply and wiper contacts for stopping the motor and drive of the tape when the wiper contacts contact the conductive trailer and conductive leader; said alarm means being a lamp; a further relay and a buzzer connected in circuit with said power supply and wiper contacts for sounding when the wiper contacts contact the conductive trailer and conductive leader; and the first named, other and further relays all having different time delay characteristics, such that the lamp is lighted, the buzzer is sounded and the motor is stopped at different times after the wiper contacts contact the trailer and leader.