Patents Examined by Kathlen M. Christman
  • Patent number: 6293800
    Abstract: An educational and entertainment device includes n layers stackable in a predetermined order one on top of the other to define a tower having n layers. The xth layer, where x varies between 1 and n, is divided into x sections, at least one of the x sections of the xth layer having a passage segment formed therethrough such that with the n layers stacked one on top of the other in the predetermined order, the passage segments of the n layers are in communication with each other to define a passage which extends through the tower. The device also includes an indicator element passable through the passage to confirm that the n layers have been assembled in the predetermined order.
    Type: Grant
    Filed: May 13, 1999
    Date of Patent: September 25, 2001
    Inventor: John Robertson