Patents by Inventor Albert M. Eldridge

Albert M. Eldridge 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: 4081911
    Abstract: A sundial comprises a body portion having a cylindrical wall. A gnomon is connected to the body portion to cast a shadow on the cylindrical wall. A pair of flexible sheets are alternately mountable on the cylindrical wall. Fasterners allow rotation of the sheets about the longitudinal axis of the cylindrical surface to correct for differences between local civil time and standard time of the time zone of observation. The time lines are configured in accordance with the equation of time. Each sheet contains time lines which designate the time occurring in either the fall or spring solstice.
    Type: Grant
    Filed: October 4, 1976
    Date of Patent: April 4, 1978
    Inventor: Albert M. Eldridge
  • Patent number: 4028813
    Abstract: A sun compass comprises a base, including a transparent hemisphere, a body movable within the base, and a plate including a dial face movable upon the body. Actuating members are connected to the plate and body for selectively moving the plate relative to the body and moving the body relative to the hemisphere. The actuating members are accessible externally of the hemisphere and include rotatable knobs having scales associated therewith for indicating the amount of movement of the plate and body. A transparent hemispherical top is mounted over the base hemisphere.
    Type: Grant
    Filed: October 22, 1975
    Date of Patent: June 14, 1977
    Inventor: Albert M. Eldridge