Patents by Inventor Donovan M. Janssen

Donovan M. Janssen 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: 4229774
    Abstract: A record storage apparatus consisting of a stack of co-rotating spaced apart flexible record storage disks are stabilized by circumferentially uniform radially outwardly flowing air under a quiescent operating condition. The record storage disks are normally in a parallel relationship. To form a transducing access opening, the disks are axially partially moved to create an enlarged interstice between two of the record storage disks for enabling a transducer to reach a recording surface on one of the two record storage disks. Disks adjacent to such access openings come closer together but should not touch. To avoid the touching and maintain stability, air flow between such more closely spaced disks is automatically adjusted as the disks approach each other.
    Type: Grant
    Filed: January 2, 1979
    Date of Patent: October 21, 1980
    Assignee: International Business Machines Corporation
    Inventors: Donovan M. Janssen, Anton J. Radman, Jr., William S. Seaward
  • Patent number: 4208684
    Abstract: A head mount faithfully follows flexible media perturbations. The head mount consists of a pivoted rigid head support arm controlled by an offset spring having an offset damping and yieldably urging relationship to the rigid arm. The rigid arm acts as a free beam. The arm is pivoted to a record support radially movable with respect to a record disk.
    Type: Grant
    Filed: May 11, 1978
    Date of Patent: June 17, 1980
    Assignee: International Business Machines Corporation
    Inventors: Donovan M. Janssen, Raymond E. Kellow, Sr., William A. Picker, Anton J. Radman, Jr.
  • Patent number: 4164768
    Abstract: A self-ventilating flexible disk pack receives operating air through a plenum chamber which communicates with the atmosphere through a flow controller. The flow controller has primary and secondary flow passages through which the flow of air is controlled by primary and secondary valves. The primary valve is used to control the creation and termination of an access opening between preselected disks. Upon closing the primary valve the flow of air into the disk pack is blocked and a high vacuum is created which allows a preselected partial split to rapidly open into a full access opening. After the primary valve is closed, a secondary valve member moves to a position in which it is responsive to the pressure within the plenum chamber for restricting and regulating the flow of air so as to maintain a bistable condition maintaining the access opening.
    Type: Grant
    Filed: September 1, 1978
    Date of Patent: August 14, 1979
    Assignee: International Business Machines Corporation
    Inventors: Donovan M. Janssen, Anton J. Radman, Jr.