Patents Assigned to Direct Educational Services Limited
  • Teaching aid
    Patent number: 6676415
    Abstract: A teaching aid comprises a frame (1), a plurality of elongate rods (2) mounted horizontally in the frame and spaced vertically from each other and a plurality of polyhedral blocks (3) rotatably mounted on each rod. Means are provided to releasably hold each block (3) in at least three discrete rotary positions on its respective rod (2).
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: January 13, 2004
    Assignee: Direct Educational Services Limited
    Inventors: Roger Walker, Graham Hiskett