| 摘要 |
<p>PURPOSE:To educe the cost of the drum assembly without increasing the side and weight thereof by mounting an annular part previously formed with spiral grooves atop a stationary drum. CONSTITUTION:The annular part 16 previously formed with the spiral grooves 14 of a pump out type is fixed atop the stationary drum 2 without subjecting the drum to direct working in the case of formation of the spiral groove shape in the relative rotating part of the drum. The height of the spiral groove surface of the annular part 16 is set at nearly the same size as the height of the top end face of the stationary drum 2 and an inclined surface is provided at the terminal part on the outer side of the grooves at the time of mounting the above-mentioned annular part. The grooves are formed without increasing the size and weight of the assembly and the cost thereof is reduced by using the annular part 16 of the separate body in such a manner. The tape damage by the groove edges is prevented and the stable tape traveling is obtd.</p> |
