Patents by Inventor James Bjordahl

James Bjordahl 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: 5666252
    Abstract: A front panel for a magazine-loading DAT drive assembly having a tape cassette drive unit above a magazine receiving area is provided with two hinged doors. By orienting two pairs of abutments in opposite directions and positioning two springs such that they exert opposite torques on their respective pairs of abutments, the door will be biased to its closed position regardless of whether it has been swung in one direction to its loading position, or in the other direction to its unloading position.
    Type: Grant
    Filed: July 22, 1994
    Date of Patent: September 9, 1997
    Inventor: James Bjordahl
  • Patent number: 5469310
    Abstract: An automated cassette loader system includes a front loading tape drive mounted in a standard height enclosure with a removable magazine including cassettes stored in front to rear alignment in two levels. The cassettes are pushed between entry and exit positions by pushing one cassette out of a push position in one level and then pushing a cassette from a push position in the other level. The cassette pushed out of the magazine is transported to the front loading tape drive and, when removed therefrom, transported to the intake of the other level of the magazine.
    Type: Grant
    Filed: September 29, 1992
    Date of Patent: November 21, 1995
    Assignee: WangDAT, Inc.
    Inventors: Richard T. Slocum, James Bjordahl, Danny Louie, Donald Rasmussen
  • Patent number: 4305536
    Abstract: An apparatus for guiding a span of high-speed magnetic recording tape past a recording/transducing head. Low volume pressurized air is utilized to lift the tape off of the guide assembly thereby eliminating sliding friction between the apparatus and the tape. The periphery of the guide is provided with a means to facilitate the formation of an air seal with the edges of the tape thereby substantially isolating the pressurized air from the atmosphere. Air jets are provided at the tangent points where the tape enters and departs from the air guide so as to prevent the tape from touching any portion of the guide during the transport operation. The pressurized air emitted from the air jets located at the tangent point where the tape enters the guide forms a supporting boundary layer of air along the surface of the tape which is carried along by the tape across the guide.
    Type: Grant
    Filed: July 18, 1980
    Date of Patent: December 15, 1981
    Assignee: BASF Aktiengesellschaft
    Inventors: Donald L. Burdorf, James Bjordahl
  • Patent number: 4275427
    Abstract: Apparatus for accurately positioning a transducer head relative to parallel tracks on a recording medium such as magnetic tape. The apparatus includes a frame having a guide to direct the tape along a horizontal path past the transducer head, and a cam mounted for rotation on the frame. The cam has a cylindrically shaped upstanding portion in which a series of graduated planar steps is formed, each such step corresponding to a separate track on the tape. The apparatus further includes a lever having one end pivotally mounted to the frame and a remote end positioned to bear on one of the steps of the cam, and a platform assembly which carries the transducer head and which bears on a mid-portion of the lever. Rotation of the cam raises or lowers the remote end of the lever by a controllable number of steps, and thereby raises or lowers the transducer head by a corresponding but lesser amount, to align it with a selected track on the tape.
    Type: Grant
    Filed: January 23, 1978
    Date of Patent: June 23, 1981
    Assignee: BASF Aktiengesellschaft
    Inventor: James Bjordahl
  • Patent number: 4144549
    Abstract: The present invention relates generally to a transducer positioning and adjusting apparatus and, more particularly, to an improved system for accurately and reproducibly positioning a transducer head in vertical relationship to a series of parallel horizontal tracks on a recording medium such as magnetic video tape. The apparatus comprises a frame upon which the elements of the system are mounted and with respect to which they are vertically aligned. A cam having a plurality of horizontally planar steps formed about its upper surface is rotatably mounted upon said frame and a vertically moveable bearing post, which is secured at one end to the transducer head, is held in continuous contact with the stepping surfaces formed on the cam. A ball bearing which contacts the underside of the cam substantially beneath the stepping surface upon which the bearing post is held in contact is utilized to support the cam on the mounting frame and maintain said stepping surface in precise vertical alignment therewith.
    Type: Grant
    Filed: November 21, 1977
    Date of Patent: March 13, 1979
    Assignee: BASF Aktiengesellschaft
    Inventors: Donald L. Burdorf, James Bjordahl, Roger S. Kincel, Harold E. Arns
  • Patent number: 4093150
    Abstract: An improved method and apparatus for generating constant tape or web tension in a transport system of the type wherein the supply and take-up reels are simultaneously driven by surface engagement with a capstan. Uniform tension is maintained throughout the entire tape pack by balancing the supply reel peripheral velocity rate of change occurring during the transport operation to the greater, but correspondingly sloped, take-up reel peripheral velocity rate of change. This balancing of the peripheral velocity of the supply and take-up reels is achieved through utilization of a constant braking system that combines the effects of torque and bias forces acting on the supply reel so as to produce constant tape tension in the take-up reel.
    Type: Grant
    Filed: June 13, 1977
    Date of Patent: June 6, 1978
    Assignee: BASF Aktiengesellschaft
    Inventors: Donald L. Burdorf, James Bjordahl
  • Patent number: 4049216
    Abstract: A method of generating constant tape tension in a tape transport apparatus of the type in which the supply and take-up reels of tape are simultaneously driven by surface engagement with a driving capstan.The method involves the utilization of a flexible but relatively inelastic belt around the periphery of resilient capstan material to introduce reel size-related supply and take-up reel velocity adjustments to counteract the similar but opposite velocity adjustments which inherently occur through the use of a resilient capstan and which, if uncompensated, result in undesirable tension variations during the course of the tape transporting operation.
    Type: Grant
    Filed: May 6, 1975
    Date of Patent: September 20, 1977
    Assignee: BASF Aktiengesellschaft
    Inventors: Donald L. Burdorf, James Bjordahl