RICHARD WARREN VAN PELT
Pilots at Laurel Ave, Boulder, CO

4953044, Aug 28, 1990

Oct 28, 1988

7/264365

Richard W. Van Pelt - Boulder CO
Patrick K. Wong - Louisville CO
Joseph W. Kern - Lafayette CO

Storage Technology Corporation - Louisville CO

G11B 1546

360 7309

A tape threading arm mechanical linkage undergoes significant variations in mechanical advantage through its motion. In order to compensate for the drastic changes in the mechanical advantage of the tape threading arm, the operation of the tape threading arm is divided up into a plurality of control segments. Each segment represents a portion of the tape threading path wherein the mechanical advantage of the tape threading arm remains fairly constant. A control memory stores data indicative of various control parameters that are required to regulate the operation of the tape threading arm motor to maintain the tape speed throughout this segment of the tape threading path at a constant velocity. In addition, the measured velocity of the magnetic tape as it is removed from the file reel is used to compute the difference between the predicted operation of the tape threading arm and the measured operation of the tape threading arm. The difference between the expected and measured operations is used to generate feedback signals to vary the current in the tape threading arm motor and the file reel motor to maintain a constant tape velocity, tape tension and minimum torque load on the tape threading arm.

4470082, Sep 4, 1984

Jul 6, 1982

6/395605

Richard W. Van Pelt - Boulder CO
Donald F. McCarthy - Jefferson County CO

Storage Technology Corporation - Louisville CO

G11B 509, H03L 710

360 51

A data clocking and detection system for a digital data storage system includes a common controlled oscillator for the multiple tracks. A phase detector for each track includes a counter and decoding circuitry producing outputs representing the time occurrence of transitions in the data with respect to bit cells defined by multiple clock pulses for each bit cell. Phase errors are used to control the frequency of the VCO, and large phase errors are used to add or subtract a count from the phase counter in each phase detector.