Patents by Inventor Thomas S. Petersen

Thomas S. Petersen 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: 5268207
    Abstract: In a process for manufacturing a rigid magnetic recording disk, the disk's rigid substrate member is subjected to a force that produces plastic deformation in a manner so as not to remove material therefrom. In this way, the disk is provided with a surface topography that contains a controlled texture, for example in the area of the disk's start/stop track. In an embodiment of the invention, an ultrasonic probe and a disk shaped substrate member are placed in close proximity within a container that holds a fluid abrasive slurry, i.e. a suspension of hard particles in a liquid. Operation of the ultrasonic probe, as the substrate member rotates, causes the slurry to texture an adjacent portion of the substrate member by means of plastic deformation and in the absence of material removal from the substrate member. Operation of the probe thus provides texturing of the disk at an inner diameter track area thereof, for example in the disk's start/stop area.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: December 7, 1993
    Assignee: International Business Machines Corporation
    Inventors: Bruce P. Kruger, Thomas S. Petersen, Steven F. Starcke
  • Patent number: 4973496
    Abstract: A magnetic disk is rotated while a tape of initially abrasive free permeable cloth tape is fed around a roller in engagement with a radial region of the disk surface. A slurry with free abrasive particles is applied to the tape prior to engagement of the tape with the disk. The roller is radially oscillated and the oscillation frequency is related to the disk rotation speed to abrade grooves in the disk surface in a pattern in which grooves vary from the circumferential direction by no more than a maximum angle of 5 to 45, preferably 8, degrees. The slurry application is halted and a rinse liquid is applied to the disk surface while the feeding of clean tape continues. Thin film layers including a magnetic medium are deposited on the abraded disk surface. The groove pattern may be abraded on the entire magnetizable area of the disk surface or may be restricted to the head landing area.
    Type: Grant
    Filed: November 2, 1989
    Date of Patent: November 27, 1990
    Assignee: International Business Machines Corporation
    Inventors: Bruce P. Kruger, Thomas S. Petersen