| 摘要 |
<p>PURPOSE:To permit a wide tape to float evenly and stably by providing many thin grooves, whose ends are both elongated up to the circumferences of both the ends of a magnetic tape, on the outer circumferential surface of a head drum in its circumferential direction and then by providing fine air holes near both terminals of each thin groove. CONSTITUTION:Head drum 1 is driven as shown by arrow A in operation and compressed air supplied into drum 1 is flowed out of air holes 11a and 11b and led into the gap between magnetic tape 2 and drum 1. The width of each groove 10 is set not more than 1mm. and its depth more than several times the floating extent of magnetic tape 2. As a result, the compressed air flowing out of air holes 11a and 11b fills the whole grooves extending in the drum axis in the tape winding region and then flows out of respective grooves 10 from groove ends 10a and 10b to the tape edge. In the tape winding region except near the tape entrance and exit, the compressed air is neither supplied nor flowed out between air holes 11a and 11b, and consequently constant pressure is maintained over the length region of thin grooves 10, so that the tape will float evenly in this region.</p> |
