Cube of eight sections - has identical curved groove on each inside face of each cube section

摘要

The cube is built up of eight like cube sections in rows of two, the faces of four adjacent sections being coupled together and turning in relation to each other. Each section has in each of its three sides towards the inside of the cube an identical curved groove (7), centred precisely on the corner where the three sides concerned join. The grooves of adjacent cube sections fit precisely together, so as to form circular passages in lengthwise sectional view, filled with complementary circular components. Rails are included, whose maximum length is equal to one quarter of the circle periphery, and form the only coupling, broken by turning, between adjacent cube sectioned. Each rail is so positioned that except when turning it is only in contact with two cube sections simultaneously.