Patents Assigned to E. S. Ritchie & Sons, Inc.
  • Patent number: 4020559
    Abstract: A portable hand-held compass for taking navigational bearings on distant objects during the day or at night. The compass has a hollow housing in which a compass card is mounted for rotation about a vertical axis, a viewing window in the housing through which compass readings are taken, and a sighting barrel incorporated in the housing for viewing a distant object along a horizontal viewing path. The compass also has a manually activated light emitting diode for illuminating a reticle, a semi-reflective mirror positioned across the sighting path for reflecting an image of the illuminated reticle to the eyepiece of the sighting barrel, means for automatically unclamping the compass card when the L.E.D. is activated, and means for automatically clamping the compass card when the L.E.D. is deactivated.
    Type: Grant
    Filed: December 22, 1975
    Date of Patent: May 3, 1977
    Assignee: E. S. Ritchie & Sons, Inc.
    Inventor: Allen Butman Sherman