The pyramid has a base plate (1) and rotatable vertical shaft (2) with two or more superposed plates (3) and frame plates (5). The frame plate (5) of at least one of the rotary movable plates (3) contains a fixedly mounted structural part (8) which has recesses (9) for rotational bodies (10) whose diameter is greater than the thickness of the structural part. The rotational bodies rest on the rotary plate and a further plate (11) rests on the rotational bodies. This additional plate (11) has a centre bore (12) whose diameter is slightly larger than the diameter of the vertical shaft. The frame plate can be hexagonal with a recess for holding the rotary plate (3) and angular sections.
