Erasing head for use with multi-track magnetic tape

Claim 1

The combination of a magnetic tape having a plurality of record tracks extending along said tape to receive recorded signals and each having a width that is substantially smaller than the width of said tape, and a magnetic erasing head having a contact surface that is at least as wide as said tape and is engageable with the latter during relative movement of said tape and head in the longitudinal direction of the tape, said head comprising a plurality of united ferrite layers superposed on each other and presenting continuous, monolithic exposed edge surfaces which combine to constitute said contact surface without interruptions in the latter, said exposed edge surfaces extending parallel to said direction of relative movement, half of said ferrite layers being permanently magnetized and having a width substantially equal to said width of each of the record tracks, the remainder of said ferrite layers being non-magnetic, each said permanently magnetized layer being aligned with one of said record tracks, in one position of the tape relative to said head, and with another of said record tracks when the tape is inverted, each said permanently magnetized layer presenting a series of alternately opposed poles at locations along said continuous, monolithic exposed surface thereof for erasing signals from the one of said record tracks which is then aligned with said magnetized layer in response to said relative movement of the tape and head.