Five-piece umbrella cover

Abstract

A five-piece umbrella cover includes a primary cover and four secondary covers each securely attached to a corresponding one of the sides of the primary cover. The primary cover is square and may be composed of multiple auxiliary covers. The four corners of the primary cover are not attached to any of the secondary covers. Angles defined by ribs are not all the same.

What is claimed is:  
     
         1 . An umbrella cover for use with N×4 ribs, the umbrella cover comprising a central square primary cover and four secondary covers, each securely sewn to a corresponding one side of the primary cover, wherein protruding corners of the primary and secondary covers are adapted to connect with a corresponding one of the ribs, wherein the improvements comprise: 
 each side of the primary cover corresponding to a big angle defined between two adjacent ribs and angles between two adjacent big angles being small angles, wherein the number of big angles is four and the number of small angles is (N−1)×4.  
 
     
     
         2 . An umbrella cover for use with N×4 ribs (where N>3 and N is natural number), the umbrella cover comprising a central square primary cover and four secondary covers each securely sewn to a corresponding one of sides of the primary cover, wherein protruding corners of the primary and secondary covers are adapted to attach to a corresponding one of the ribs, wherein the improvements comprise: 
 two adjacent secondary covers corresponding to two small angles defined between two adjacent ribs and angles between two separated small angles being big angles, wherein the number of small angle is 8 and the number of big angles is M×4 (M≧1) and N(x)=M; x is a variable.  
 
     
     
         3 . An umbrella cover for use with twelve ribs, the umbrella cover comprising a central square primary cover and four secondary covers each securely sewn to a corresponding one of sides of the primary cover, wherein protruding corners of the primary and secondary covers are adapted to attached to a corresponding one of the ribs, wherein the improvements comprise: 
 the secondary cover being composed of a trapezoid and two triangles formed on opposite sides of the trapezoid.    
     
     
         4 . An umbrella cover for use with twelve ribs, the umbrella cover comprising a central square primary cover and four secondary covers each securely sewn to a corresponding one of sides of the primary cover, wherein protruding corners of the primary and secondary covers are adapted to attach to a corresponding one of the ribs, wherein the improvements comprise: 
 the secondary cover being composed of a trapezoid, a triangle formed on two opposite sides of the trapezoid and a sectorial area between the trapezoid and the triangle.