Sewer grate with insect block

Abstract

A water sewer drainage system particularly directed to prevent spread of West Nile disease includes an underground water drain off region, a ground level opening to a down passage to the drain off region, a sewer grate across the ground level opening and an insect block in the down passage below the sewer grate. The insect block inhibits insects from gaining access to the drain off region while permitting flow of water through the system.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A sewer drainage system, said system including an underground water drain off region, a ground level opening to a down passage to said drain off region, a sewer grate across said ground level opening and an insect block in said down passage below said sewer grate, said insect block inhibiting insects from gaining access to said drain off region while permitting flow of water through said system.  
     
     
         2 . A sewer drainage system as claimed in  claim 1  wherein said insect block comprises a rigid flap which is pivotally held within said system, said flap being biased to normally assume a down passage blocking position and said flap when exposed to water flow thereon being moved to a down passage opening position.  
     
     
         3 . A sewer drainage system as claimed in  claim 2  including a pivot mount at one end of said flap for pivotally securing said flap within said down passage of said system, said pivot mount including a spring which biases said flap to the down passage blocking position.  
     
     
         4 . A sewer drainage system as claimed in  claim 2  wherein said flap includes first and second flap parts fixedly held with one another at a pivot mount of said flap, said flap parts being balanced to opposite sides of said pivot mount to urge said flap to the down passage blocking position.  
     
     
         5 . A sewer drainage system as claimed in  claim 4  wherein said flap has an angled configuration with an apex at said pivot mount and said first and second flap parts being angled downwardly to opposite sides of said apex of said flap.  
     
     
         6 . A sewer drainage system as claimed in  claim 2  wherein said sewer grate comprises a grate frame surrounding said ground level opening, and a grate member which is pivotally mounted to said grate frame for swinging said grate member to and away from the down passage covering position, said system including a flap mounting frame to which said flap is pivotally mounted, said flap mounting frame seating on said grate frame and being sandwiched between said grate member and said grate frame when said grate member is in the covering position, said flap frame and said flap, being liftable from said system when said grate member is away from the covering position.