Drain cover for generally open flat drainage areas with debris blockage and open drainage portions

Abstract

A drain cover having a main drainage surface with relatively larger apertures or openings therein, comprising generally 50 percent of the surface, so that larger debris is accepted into a related drain pipe when a depending skirt portion of the drain cover, having smaller perforations, becomes clogged. In this way a two-layer drainage system for a generally flat surface is provided that allows draining of water and small particulates alone when possible, but upon the clogging of the smaller openings the generally flat surface can be protected from flooding by allowing larger particulates to drain into the main drainage surface. The main drainage surface is held above the flat surface by the depending skirt, at a level of 3/8 to 1 inch above the flat surface. When the depending skirt openings are clogged the water and debris will rise until allowed to drain into the larger openings of the main drainage surface.

What is claimed is: 
     
         1 . A drain cover, for use on a drain opening in a generally flat surface, comprising:
 a plate having an aperture thereon, the aperture encompassing a desired amount of area of the surface of the plate, the plate having an edge about its perimeter; and   a skirt attached to the edge of the plate and depending therefrom, the skirt having a lower edge, for placement adjacent the generally flat surface, and perforations therethrough, to permit the flow of liquids, such that the drain cover can be positioned to accept fluid through the plate aperture only when the perforations of its skirt are blocked and water rises above the skirt.   
     
     
         2 . The drain cover of  claim 1 , wherein the drain cover and aperture are of a sufficient size to accept large leaves through the aperture. 
     
     
         3 . The drain cover of  claim 1 , wherein the skirt has a length from the edge of the plate to the drainage surface of about ½ inch. 
     
     
         4 . The drain cover of  claim 1 , wherein the skirt has a length from the edge of the plate to the drainage surface of about ¾ inch. 
     
     
         5 . The drain cover of  claim 1 , wherein the plate comprises a generally circular area and the skirt depends from the circumference thereof. 
     
     
         6 . The drain cover of  claim 5 , wherein the plate comprises structural material formed as an “X” within the circumference of the skirt. 
     
     
         7 . The drain cover of  claim 1 , including at least one leg, attached to the plate, depending therefrom for insertion into a drain pipe. 
     
     
         8 . The drain cover of  claim 7 , wherein the at least one leg comprises a friction element for removable contact with the drain pipe. 
     
     
         9 . The drain cover of  claim 7 , wherein the at least one leg is four legs. 
     
     
         10 . The drain cover of  claim 1 , further comprising a shutter to close the aperture. 
     
     
         11 . The drain cover of  claim 10 , wherein the shutter is movable so as to adjust the size of the aperture. 
     
     
         12 . A drain cover, for use on a generally flat open drainage surface, comprising:
 a generally cylindrical plate having an aperture thereon, the aperture opening in an area of the plate comprising at least 50% of the surface of the plate, the plate having an edge about its circumference; and   a perforated skirt attached to the plate and depending from the circumference of the plate, the skirt having a lower edge for placement adjacent the drainage surface such that the generally cylindrical plate is positioned to accept fluid through its aperture only when the perforations of the skirt are either clogged or otherwise insufficient to drain water and water rises above the skirt.   
     
     
         13 . The drain cover of  claim 12 , wherein the drain cover and aperture are of a sufficient size to accept large leaves through the aperture. 
     
     
         14 . The drain cover of  claim 12 , wherein the skirt has a length from the edge of the plate to the drainage surface of about ½ inch. 
     
     
         15 . The drain cover of  claim 12 , wherein the skirt has a length from the edge of the plate to the drainage surface of about ¾ inch. 
     
     
         16 . The drain cover of  claim 12 , including at least one leg, attached to the plate, depending therefrom for insertion into a drain pipe. 
     
     
         17 . The drain cover of  claim 16 , wherein the at least one leg comprises a friction element for removable contact with the drain pipe. 
     
     
         18 . The drain cover of  claim 12 , further comprising a shutter to close the aperture. 
     
     
         19 . The drain cover of  claim 18 , wherein the shutter is movable so as to adjust the size of the aperture. 
     
     
         20 . The drain cover of  claim 19 , including means to determine the optimal aperture opening and to adjust the aperture accordingly.