Patents by Inventor Donald Eric Griffiths

Donald Eric Griffiths 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: 4019204
    Abstract: Selectively altering air flow generates an access opening for a record surface on one of a large plurality of flexible record storage disks coaxially supported on a common spindle for rotation. Air flow through the interstices between the disks usually is sufficient to stabilize rotation of the disks. To generate a transducer access opening the air flow on one axial side of a record disk to be accessed, which includes a record surface, is altered in a manner that disks axially adjacent and facing the record surface tend to axially move together at their periphery, resulting in a peripheral transducer access opening adjacent a stabilized record disk. In a preferred form of the invention, the axial extent of the altered air flow is limited to a predetermined portion of the stack of disks for minimizing the volume of air flow change. For dual sided recording, the air flow is altered at either side of the record disk to be accessed.
    Type: Grant
    Filed: November 19, 1975
    Date of Patent: April 19, 1977
    Assignee: International Business Machines Corporation
    Inventors: Donald Eric Griffiths, David Gibbons Norton