Cyclic surfaces with directrix meridians of the base surface of revolution

The questions of forming of the cyclic surfaces with plane of parallelism made by the circle of the changed radius moving on two meridians of the base surface of revolution are concern. There received the vector equation of the surfaces. It is shown that on the base of those surfaces there may be constructed varies shells of umbrella type. There shown drawings of some cyclic surfaces and surfaces of umbrella type with different base surfaces of revolution.

base surface, surface of d revolution, cyclic surface, surface with plane of parallelism, umbrella surface, made by moving of the circle f the changed radius