Patents by Inventor David V. Alexander

David V. Alexander 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: 5438238
    Abstract: An improved ion source is provided with multiple filaments and wiring for selectively connecting various combinations of filaments to a current source. In one embodiment an additional filament is a spare filament which is connected to the current source when the primary filament burns out. This decreases down time due to filament replacement. In another embodiment, an additional filament operates simultaneously with a primary filament to provide a more homogenous electron cloud and to increase filament life.
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: August 1, 1995
    Assignee: NEC Electronics Inc.
    Inventors: Stephen W. Toy, David V. Alexander
  • Patent number: 5256947
    Abstract: An improved ion source is provided with multiple filaments and wiring for selectively connecting various combinations of filaments to a current source. In one embodiment an additional filament is a spare filament which is connected to the current source when the primary filament burns out. This decreases down time due to filament replacement. In another embodiment, an additional filament operates simultaneously with a primary filament to provide a more homogenous electron cloud and to increase filament life.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: October 26, 1993
    Assignee: NEC Electronics, Inc.
    Inventors: Stephen W. Toy, David V. Alexander
  • Patent number: 5095300
    Abstract: An apparatus is provided which determines whether a member is placed correctly on a base. The apparatus comprises an arm mounted for movement toward and away from the base which normally holds the member in place on the base. The arm has a projection which extends a distance beyond the surface of the arm and toward the base. When the member is in a first or third position relative to the base, the projection makes contact with the member. When the member is in a second position relative to the base, the projection clears the member and is positioned in close proximity to the side of the base. The apparatus determines the position of the member by sensing with a photosensor a corresponding position of the arm displaced from the base. The displacement distance of the arm relative to the base is due to the distance that the projection extends beyond the surface of the arm.
    Type: Grant
    Filed: March 28, 1990
    Date of Patent: March 10, 1992
    Assignee: NEC Electronics Inc.
    Inventors: David V. Alexander, Gary T. George
  • Patent number: 5058421
    Abstract: A leak and liquid level detector includes a transistor as its main operating element with a pair of normally open base contacts connected to the transistor base. The transistor emitter is connected to ground and the transistor collector is connected to a suitable audio alarm, or alarm light or to a programmable logic controller. When a liquid leak bridges over the base contacts, a power circuit is closed across the contacts biasing the transistor and causing an electrical signal to flow from the collector to actuate the alarm, light or controller. The base contacts are linearly adjustable to sense various leak heights. The detector in one mode of use can be positioned horizontally to detect leaks and in a second mode of use is positioned vertically to detect a change in a liquid level in a tank, pipe column or the like.
    Type: Grant
    Filed: June 8, 1990
    Date of Patent: October 22, 1991
    Assignee: NEC Electronics Inc.
    Inventors: David V. Alexander, Stephen W. Toy, Marvin March