GB754619A - Skylights - Google Patents

Abstract

754,619. Daylight reflectors and refractors. OWENS-ILLINOIS GLASS CO. Aug. 30, 1954 No. 25101/54. Class 20(3). In the utilization of daylight to light an interior through an opening in the roof or ceiling four air/glass interfaces are interposed in a horizontal position between the daylight and the interior, the interfaces being positioned on parallel outer and inner walls and the interior face of the outer wall is constructed and arranged so as to transmit only light from the Northern sky and sunlight from low altitudes, sunlight from high altitudes being totally internally reflected and rejected back to the exterior. This may be accomplished by making that face in the form of a series of parallel prisms having an included angle of approximate.y ninety degrees and adjusting the position of the prisms so that they extend in an East-West direction with one surface forming an angle of approximately thirty degrees with the horizontal plane and extending upwardly in a Southerly direction. In the particular example shown the included angle P is exactly ninety degrees and the angle b<SP>1</SP> twenty-nine degrees ; this combination shows the passage of rays, L3, L<SP>4</SP> from low altitude angles a3 and L5, L<SP>6</SP> from Northern angles a<SP>4</SP>, and the total reflection of rays L<SP>1</SP>, L2 from high altitude angles a<SP>1</SP>, a<SP>2</SP>. Such a combination would be suitable for a latitude 42 degrees North. Examples wherein b<SP>1</SP> is 30 degrees exactly and 31¢ degrees are also given. Prisms having different included angles and being arranged at different angles to the horizontal can be formed on the same face or all the prisms can be similar but may have adjacent portions of the Southerly-sloping surface arranged at different angles to the horizontal. The range of included angles may be 82 to 98 degrees but other examples are given wherein the range may be from 60 to 87 degrees (particularly 75 degrees) and the angle with the horizontal may then be of the order 35 to 45 degrees. The inner and outer faces of the inner wall may comprise ribs, those on one face being at right angles to those on the other, or may comprise parallel rows of depressed pyramids those on one surface being diagonal to those on the other surface. A glass fibre layer may be arranged between the two walls.