Patents by Inventor W. Kenneth Caldwell

W. Kenneth Caldwell 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: 4551847
    Abstract: A hand-held tape measure is provided which includes a conveniently sized housing with an elongated measuring tape suitably coiled on a rotatable shaft mounted within said housing. A sprocket arranged to engage the surface of the tape without slippage is mounted within the housing and drivingly connected to an encoding disk whereby the rotation of the disk is directly proportional to the linear movement of the free end of the tape. The disk is divided into an equal number of alternating transparent and opaque segments and two energy sensitive coupler switches are mounted in conjunction with the disk to provide electrical outputs indicative of the adjacent disk segment to indicate the rotation of the disk. The switches are offset circumferentially to provide a phase differential which indicates whether the tape is extending or retracting with respect to the housing. The output from the switches is fed to an electronic circuit which counts and divides the output pulses with the result digitally displayed.
    Type: Grant
    Filed: April 8, 1983
    Date of Patent: November 5, 1985
    Inventor: W. Kenneth Caldwell