Patents by Inventor Thomas S. Larson

Thomas S. Larson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5574604
    Abstract: A load/unload device to remove the slider from the proximity of the magnetic recording surface of a disk in a disk drive whenever the disk is to be stopped. The load/unload device is a ramp-like wedge which extends generally radially from the center of the magnetic disk and to the magnetic recording surface of the magnetic disk. When the slider is moved toward the center of the disk by an actuator mechanism, the end of the load arm supporting the slider, referred to as a tang, will engage the inclined plane of the wedge and lift the slider from the surface of the magnetic disk as the slider is translated closer to the center of the disk. Once the slider has been removed from close proximity of the disk, the tang may engage a trough-like surface on the structure supporting the wedge and will effectively detent the position of the slider through the forces exerted on the tang by the load beam of the actuator.
    Type: Grant
    Filed: April 4, 1995
    Date of Patent: November 12, 1996
    Assignee: International Business Machines Coporation
    Inventors: Lowell J. Berg, Zine-Eddine Boutaghou, Thomas S. Larson, Dallas W. Meyer, Jay M. Mosbrucker, Jerry L. Neubauer, Hal H. Ottesen
  • Patent number: 5557183
    Abstract: Disclosed is a disk drive having a spindle motor, a disk that is rotated by the spindle motor, and a movable actuator arm that carries a read/write head. The head physically engages a parked, or home, position at the Inner Diameter (ID) of the disk when the spindle motor is not energized and the disk is stationary. The electrical energization that must be applied to the spindle motor in order to breakaway the head from the disk (i.e., the breakaway current), and the energization that is necessary to cause the motor to achieve a stable spinning state (i.e., the spin current) are monitored. Possible future failure of the disk drive is predicted as a function of any changes in these two electrical parameters, as these parameters may change over a period of time; i.e., may change over a number of disk drive stop/start events.
    Type: Grant
    Filed: February 17, 1995
    Date of Patent: September 17, 1996
    Assignee: International Business Machines Corporation
    Inventors: Randall M. Bates, David F. Glaess, Thomas S. Larson, Patricia J. Wadkins
  • Patent number: 5530602
    Abstract: A starting sequence is provided for a rotating disk data storage device by providing a low level sensing current to the spindle motor which is able to initiate rotation of the disk spindle assembly when, absent stiction between head and confronting disk surface, it is only necessary to overcome disk assembly inertia and head drag. A sensing device is provided to sense a back electromotive force (EMF) in the spindle motor windings which indicates the start of disk rotation when any stiction condition has been terminated. A sequence of alternating current pulse bursts are applied to the actuator motor to impart a dithering action to the heads which induces axial vibration of the disks to break the stiction between the heads and confronting disk surfaces.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: June 25, 1996
    Assignee: International Business Machines Corporation
    Inventors: Zine-Eddine Boutaghou, Donald C. Buettner, Thomas S. Larson, Jaquelin K. Spong
  • Patent number: 5278711
    Abstract: A rotating magnetic storage device is shown wherein the transducer and media are separated during operation by a thin film of low viscosity liquid lubricant that is recirculated from a reservoir within the head-media enclosure. Lubricant recirculation can be effected by capillary action using a wick, mechanical pumping and metering or distillation techniques. As compared to devices using air bearing separation, the transducer carrying slider has very small bearing surfaces which may be in the form of narrow rails or small depending foot elements. This enables fly heights of 2 microinches using a film of one micron thickness.
    Type: Grant
    Filed: October 20, 1992
    Date of Patent: January 11, 1994
    Assignee: International Business Machines Corporation
    Inventors: Thomas A. Gregory, Christopher G. Keller, Thomas S. Larson