Image Number 9 for United States Patent #4727440.
A closed loop, high-speed tape transporter (10) includes a vacuum supply (11A), a first vacuum column (40) operatively connected to the vacuum supply (11A) and positioned upstream from a pick-up head (100) and downstream from a tape bin (64) for receiving the loop of tape and exerting a vacuum-induced holdback tension thereon, a second vacuum column (50) operatively connected to the vacuum supply (11A) and positioned downstream of head (100) and upstream of the tape bin (64) for exerting a vacuum-induced pull forward tension on the tape in opposition to the holdback tension exerted on the tape by the first vacuum column (40). A motor-driven capstan (60) is positioned intermediate the pick-up head (100) and the second vacuum column (50). Capstan (100) is driven at a constant speed equal to the ideal reference tape duplication speed. Tape drive capstans (62A) and (70A) cooperate with the first and second vacuum columns (40) and (50) for moving the tape. A servo-control (42 ), (45), (48) senses changes in the position of the tape within the first vacuum column (40) and sends a signal to tape drive (70A) and a servo-control (58), (55), (56) senses changes in the position of the tape within the second vacuum column (50) and sends a signal to tape drive (62A). The speed of the tape is varied as it moves through the first and second vacuum columns (40), (50) thereby minimizing tension induced speed variation in the tape in the region of the pickup head (100).
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