U.S. Pat. No. 2,454,693
by fros1y, published
A 3D model of U.S. Pat. No. 2,454,693. Cutting edge 1948 portable-chess board technology from the original Thingiverseâ€”the U.S. PTO.
"This invention concerns improvements in or relating to board or the like games which are played with pieces movable to predetermined positions upon the board."