| 摘要 |
<p>1,176,120. Magnetic heads. INTERNATIONAL BUSINESS MACHINES CORP. 20 June, 1968 [13 July, 1967], No. 29362/68. Heading G5R. Partial vacuum is applied to grooves 68, 70 &c. extending longitudinally of a magnetic head 10 to prevent the edges of a magnetic tape 40 curling. The grooves are connected to transverse slots 44, 56 connected to respective chambers 46 connected at 48, 50 to vacuum and extend up to 0À003 ins. from write 32 and read 28 transducers separated by a non-magnetic spacer 38. The groove ends are bevelled to prevent the accumulation of debris, and the transverse slots may be omitted (Fig. 6, not shown). The longitudinal grooves are provided when the heads have shaped operating surfaces of radii of curvature >0À5 ins. and when the overall wrap angle of the tape about the head <10 degrees, i.e. where the curvature of the tape is insufficient by itself to prevent curling.</p> |
