Butterfly valve for skylight

摘要

A valve for selectively blocking the light passageway of a skylight includes a cylindrical shroud and first and second semicircular butterfly valve elements that pivot on respective axles within the shroud to selectively block the skylight. The axles can ride on a common motor-driven cam between a horizontal orientation to block the skylight and a vertical orientation to allow light to pass. The motor can be powered by a universal power supply that can operate at anywhere from below 100 volts to above 270 volts.