Patent ID: 6260309
Filing Date: 2001-07-17
Classification: E04H,G02B

Abstract:
In a split-sphere observatory dome of the type comprising:a cylindrical base having a circular peripheral edge,an antrum shell having a first circular peripheral edge rotatably supported on the circular peripheral edge of the cylindrical base and a second circular peripheral edge disposed at an acute angle with respect to said first circular peripheral edge,a rotor shell having a first circular peripheral edge rotatably supported on the second circular peripheral edge of the antrum shell and a second circular peripheral edge disposed at an angle with respect to said first circular peripheral edge of said rotor shell and tangential thereto at a point, said second circular peripheral edge of said rotor shell defining the periphery of a planar oculus;wherein upon rotation of the rotor shell said oculus revolves about an axis of rotation along a path wherein the orientation of the plane of the oculus varies between a vertical orientation and a horizontal orientation;the improvement comprising:a shutter lid fixed to said antrum shell proximate said second circular peripheral edge of said antrum shell, said shutter lid covering a portion of said rotor shell and exposing a portion of said rotor shell, said oculus being revolvable between a position wherein said lid completely covers said oculus and a position wherein said oculus is completely exposed; andan oculus window rotatably supported by the rotor shell and adapted to rotate to provide a predetermined orientation between the oculus window and an instrument housed within the split-sphere observatory dome, despite rotation of the rotor shell.