Patents by Inventor David L. Hargrave

David L. Hargrave 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: 5023989
    Abstract: A hand tool is useful for extracting upwardly a shaft of a pop-up sprinkler that is biased downwardly into a cavity in the sprinkler and for maintaining the shaft in an extracted position. The tool comprises a pair of elongated members pivotally connected to each other at a pivot point to form a pair of opposed handles and a pair of opposed grippers. Biasing means are provided for biasing the grippers together. Each gripper has a projection extending outwardly from its nose end for gripping an inside wall of the shaft. Each gripper also includes a cut-out portion on its inside surface so that the two cut-out portions form an opening shaped to firmly grip the outside wall of the extracted sprinkler shaft. When the tool is placed on the sprinkler shaft, due to the force of the biasing means, the tool firmly grips the sprinkler shaft and prevents it from dropping downwardly into the recess.
    Type: Grant
    Filed: November 22, 1989
    Date of Patent: June 18, 1991
    Inventor: David L. Hargrave