GB938017A - Improved surface drain and grating therefor - Google Patents

Abstract

938,017. Roof drainage. J. S. NEWMAN. Feb. 15, 1961, No. 5692/61. Class 33. A surface drainage structure comprises a drain body 10, Fig. 3, of cup-shaped formation in the lower end of which is an outlet 11 with which a junction member 12 integral with the body 10 communicates to connect it to a drainage system; a peripheral rim 13 around the body's upper end as shown for the inlet 14 whereat a grating 16 is located and supported comprising bars 22, each having the broader dimension of its cross-section perpendicular to the grate surface and the narrower in the plane of the grate surface, and oriented and dimensioned to provide free drainage area for liquid passage into the body 10 of at least fifty per cent. of the total area of the inlet 14. In the form shown an intersecting and supporting cross-member 23 extends across the grating bars 22, Fig. 2, and a frame 17 extends around the perimeter of the grating 16 to support the bars 22, lugs 18 as shown with feet 19 engaging a ledge 15 around the rim 13 to support the grating 16. The depth dimension of the bars 22 is made equal to at least five per cent. of the overall diameter of the inlet 14, the width dimension of the frame 17 is approximately twice that of the bars 22, and the depth dimension is substantially the same as that of the bars 22. The frame 17 is of reduced thickness adjacent the junction between the rim 13 and the drain body 10. The bars 22 have a crosssectional profile which is tapered as shown in Fig. 3. A flange 31, around the exterior of the body 10 retains liquid seepage thereat, which passes into the interior through apertures 30 in the body 10. In a modification, Fig. 5, a trap member 32 is supported by lugs 37 on a ring 36 on the ledge 15 and has side openings 35 and a perforated floor portion 33 for straining liquid, side members 34 retaining solids therein.