| 摘要 |
<p>PURPOSE:To prevent a magnetic tape from contacting with the edge of a space part by the pressure of an air film between a rotary cylinder and the magnetic tape by cutting away the circumferential part of the cylinder in a groove shape near the head position of the cylinder. CONSTITUTION:The circumferential part of the rotary cylinder 4 which has an axial center in the direction of an axial line A-A is cut away. This axial line A-A is directed in the tangential direction of the rotation of the rotary cylinder 4. A ground part 9 is formed so that this cylindrical shape overlaps a space part 8. For this purpose, only the circumferential part near the edge 7 of the space part 8 is cut away in the groove shape and moved back inwardly. Further, removed parts on both ends of the ground part 9 are slightly and the rotary cylinder 4 is removed greater toward the center. Therefore, the variation in flow passage area of air is made smaller where the head is positioned than before to reduce variation in air pressure, thus reducing the waving of the tape.</p> |
