Vlastnosti niektorých obalových skrutkových plôch
Properties of enveloping helicoidal surfaces, generated by helicoidal movement of developable line surfaces, are treated. A construction is given of the characteristic of an enveloping helicoidal surface, of its axial sections, of its sections by planes perpendicular to the axis of helicoidal movement, and ot the plane tangent to a characteristic at a general point of the surface.