Column wheel and chronograph mechanism including the same

A column-wheel for a three stroke chronograph mechanism including:

• a ratchet provided with 3*n teeth;
• a central hub;
• a superstructure coaxial to the column wheel and exhibiting rotational symmetry of order n, the superstructure comprising n radial arms and n columns parallel to the axis of rotation of the column wheel, the columns being regularly distributed along the circumference of the column wheel and separated from each other by n empty spaces forming as many openings between the columns, each column including an external face and an internal face connected to each other by a leading edge and by a trailing edge, the external face having a rounded shape concentrically to the axis of rotation of the column wheel, and the internal face begin connected to the hub by a radial arm,
• wherein the width of the columns measured between the leading edge and the trailing edge is larger than the width of the openings between the columns, and wherein the width of the arms at the narrowest point thereof is less than half the width of the columns.