Geometric construction kit
Patent 3998004 Issued on December 21, 1976. Estimated Expiration Date: 
December 21, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 21, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1236234 2776521 2872754 3196579 3426453 InventorApplicationNo. 580981 filed on 05/27/1975US Classes:446/92, Including permanent magnet or suction cup to secure elements428/900MAGNETIC FEATUREExaminersPrimary: McNeill, G. E.Assistant: Cutting, Robert F. Attorney, Agent or FirmInternational ClassA63H 33/04 (20060101)AbstractThis invention employs a multiplicity of polygon-shaped members having magnetic edges which permit the members to be easily joined in order to fabricate two- and three-dimensional objects such as polygons and polyhedra for recreational and/or educational use. | |
