Patents by Inventor David L. Key

David L. Key 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).

  • Racquet string actual tension measuring device
    Patent number: 5299462
    Abstract: A method for measuring the actual tension in an elastic string such as in a strung racquet. The method comprises holding one length of string (42) substantially a constant length, and measuring the force (58) required to maintain this length, while the tension in an adjacent section of string (36) is reduced to zero. Once the tension in the adjacent section of string has been reduced to zero, the force maintaining the first section of string a constant length is an indication of the actual string tension.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: April 5, 1994
    Inventor: David L. Key