Patents Assigned to Idea Didattica Editrice
  • Instrument for facilitating the calculation of equivalent values
    Patent number: 4057912
    Abstract: An instrument for facilitating the calculation of equivalent values includes a plate bearing symbols representing units and dimensions, the plate having a window in which a movable pointer is located. The pointer is movable from a first position representing a first set of units and dimensions to a second position representing an equivalent set of units and dimensions.
    Type: Grant
    Filed: May 21, 1976
    Date of Patent: November 15, 1977
    Assignee: Idea Didattica Editrice
    Inventor: Francesco Di Noia