| 摘要 |
<p>PURPOSE:To reduce the discontinuous fluid force mechanism working on a tape and to evade the oscillation of the tape by stably securing the air flow pass to a vacuum room from the atmosphere and varying the air flow pass continuously against the positional variation in the external direction of the tape surface. CONSTITUTION:In the case of a tape tension being reduced, the equilibrium becomes unbalanced and a tape 15 is attracted into a vacuum chamber 16 by the negative pressure. According to the movement of the tape 15 the part faced to the atmosphere of the groove part 14 provided on a base 5 is increased. So a lot of air become to flow in from the atmosphere by a vacuum chamber 16 but by making the shape of the end part of the groove part 14 in base 5 inclined shape, the sectional area of the air flow pass is continuously enlarged. As a result of the increase of such a flowing-in air, the degree of vacuum of the vacuum chamber 16 is continuously lowered, the negative pressure working on the tape 15 is reduced and the tape 15 is pulled out to the air side by tension this time. The discontinuous fluid force working on the curved part of the tape is thus reduced and the oscillation of the tape can be evaded.</p> |
