Drain grate with adjustable weirs

In a self supporting foraminous grate for a drain structure an improvement which comprises:

• said grate having an exterior and an interior, said exterior of said grate communicating with the ambient environment, said interior of said grate communicating with said drain structure such that fluid in the interior of said grate passes into said drain structure;
• a portion of said grate formed as a mounting base, said base sized and shaped to attach to said drain structure maintaining said grate on said drain structure;
• a portion of said grate formed as a generally upwardly projecting wall integrally formed with and extending upwardly from said base, said wall formed as a continuous surface of revolution;
• a portion of said grate formed as a top surface integrally formed on the uppermost periphery of said wall, said top surface including a plurality of openings in said top surface;
• a portion of said grate formed as a guard lip integrally formed with and extending upwardly from said base and culminating in a top edge, said guard lip retarding the flow of solid material towards said wall, said guard lip radially displaced outwardly from wall;
• a plurality of weirs located in said wall forming a fluid passageway from the exterior of said grate into the interior of said grate;
• said weirs located in said wall in a symmetrical array around the surface of revolution of said wall, each of said weirs shaped as an elongated triangle with the base of each said triangle located proximal to said top surface and the apex of each of said triangles located proximal to said base so as to allow fluid at a first fluid level on said wall proximal to said base to flow at a first rate from the exterior of said grate into the interior of said grate and fluid at a second fluid level on said wall displaced upwardly from said base from said first fluid level to flow at a second rate which is greater than said first rate;
• said wall includes a fluid imperforate area located on said wall and extending between said base and the apex of each of said triangular shaped weirs, said imperforate area forming a dam wall between the exterior of said grate and the interior of said grate inhibiting fluid flow into the interior of said grate;
• said guard lip is continuous around said wall;
• said top edge of said guard lip including a plurality of notches located therein;
• said top edge of said guard lip is located at a height greater than said apex of each of said triangular shaped weirs;
• said notches in said guard lip are V-shaped and the lowest most portion of said notches are of a greater elevation from said base than is said apex of each of said weirs.