Procédé pour produire des sphères creuses, sphères creuses produites par ce procédé et appareil pour la mise en oeuvre de ce procédé

摘要

572,248. Roof-lights. PEVERLEY, R. St. L. Dec. 1, 1943, No. 20076. [Class 20 (iii)] The frame of a roof-light ventilator &c. is corrugated or shaped otherwise to conform to the roofing sheets and the ledge on which the glass C rests is lowered at the upper end A' of the light to below the level of the bottoms of the corrugations a to permit the passage of rain water from them on to the surface of the glass c. At the lower end A<2> the frame is cut away to allow the water to run away from the glass: