Abstract: A railroad car incorporating a pair of wheel carriages, each wheel carriage holding four wheels, and pivotally connected to a housing 8, the housing having a lower clearance passage provided through its bottom, an upper longitudinally inclined slot, opening to its top, and an aperture therethrough, and through which a fastener may locate, for pivotal securement of the wheel carriage to the underside of a railroad car.

Abstract: A set of universal blocks includes a plurality of uniform-sized cubic elements, a plurality of uniform-sized connecting elements, and at least one disassemble aid. The cubic element each is provided at all six sides with an insertion hole each. The connecting element each is adapted to insert into the insertion holes on the cubic elements and has a length twice or almost twice as long as that of the insertion holes. The disassemble aid is a long flat element provided with a plurality of through holes adapted to easily disassemble the connecting elements from the cubic elements. The cubic elements may be freely connected to one another via the connecting elements to create a variety of two-dimensional and three-dimensional geometric shapes, and be conveniently used to play various kinds of games, including puzzles.