Telex Computer Products, Inc.

Robert F McCollum

Robert J Jones

Philip E Deck

This abstract describes apparatus for improving the operation of magnetic tape decks which have two parallel wall vacuum columns and two tapered wall vacuum columns, in which means are provided to minimize the tape excursion in the tapered columns. Because of the small mass of the tape in the tapered colUmns, the tape can accelerate very rapidly, and when doing so may cause a reversal of air flow from the vacuum columns acting like an air pump, for example, when the tape is moving outwardly. In the tapered column, with wide excursiOns of the tape, there is danger of flutter and oscillation when the tape force varies in a pulsating manner and a resonance can be set up. A check valve is applied between the tapered vacuum column and the vacuum plenum, so that when there is an outward excursion of the tape the check valve will close and there will be an increasing vacuum in the column. This will provide a greater force restricting outward movement of the tape.

Tape excursion control means using tapered-wall vacuum column

This invention covers means in connection with magnetic recording devices, to position, latch and remove reels from a driving hub, and actuation means therefor. The hub onto which the tape reel is placed carries an elastic sleeve about which the reel is placed. An actuation rod which passes through the hollow shaft of the drive motor carries a spool, to which three link bars are hinged. These are in radial planes spaced at 120.degree. to each other. The link bars are attached respectively to three shoes which are adapted to press outward against the inside wall of the elastic sleeve, which expanded outward against, and securely grips the reel hub. Also involved in the linkages between the link bars and the shoes are three dogs, which are adapted to press the reel hub against the drive hub and/or to lift the reel hub, depending on the position of the actuator rod. The actuator rod is adapted to be operated in push-pull fashion by a handle on the front face of the mechanism, or by means of a vacuum actuator mounted behind the reel drive motor.

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Oklahoma City, OK, United States of America

Robert F McCollum