Marine propeller blades with reverse cupping

Abstract

A propeller has a plurality of blades extending radially outwardly of a hub and a plurality of cups respectively affixed to the plurality of blades. Each of the plurality of blades has a facing surface and a back surface. The blade has a leading edge and a trailing edge. The cup is affixed to the back surface of the blade in spaced relation to the trailing edge and in spaced relation to the outer edge. The cup is affixed to a greatest thickness of the blade. The cup has a curvature corresponding to a curvature of the blade. The blade is positioned at approximately ⅔ of a width dimension from the leading edge.

I claim: 
     
         1 . An apparatus comprising:
 a blade having a facing surface and a back surface, said blade having a leading edge and a trailing edge, said blade having an outer edge; and   a cup affixed to said back surface of said blade, said cup being in spaced relation to said trailing edge and in spaced relation to said outer edge   
     
     
         2 . The apparatus of  claim 1 , said blade having a variable thickness between said leading edge and said trailing edge, said blade having a greatest thickness in an area between said leading edge and said trailing edge, said cup affixed to said blade at said greatest thickness. 
     
     
         3 . The apparatus of  claim 1 , said blade having a curvature, said cup having a curvature corresponding to said curvature of said blade. 
     
     
         4 . The apparatus of  claim 1 , said blade having a radius, said cup positioned in an area between 80% and 90% of said radius. 
     
     
         5 . The apparatus of  claim 1 , said blade having a width dimension between said leading edge and said trailing edge, said cup positioned at a location corresponding to ⅔ of said width dimension. 
     
     
         6 . The apparatus of  claim 1 , said cup extending outwardly of said back surface of said blade for a distance between ⅜ inch and ½ inch. 
     
     
         7 . The apparatus of  claim 1 , said blade rotatable in a forward direction a rearward direction, said leading edge being in a rearward direction. 
     
     
         8 . The apparatus of  claim 1 , said cup being mechanically affixed to said blade. 
     
     
         9 . A propeller comprising:
 a plurality of blades extending radially outwardly of a hub, each of said plurality of blades having a facing surface and a back surface, each of said blades having a first edge and a second edge and an outer edge; and   a plurality of cups respectively affixed to said plurality of blades, each of said plurality of cups affixed to said back surface of the blade, said cup being in spaced relationship to said second edge and in spaced relationship to said outer edge.   
     
     
         10 . The propeller of  claim 9 , each of said blades having a variable thickness between said first edge and said second edge, each of said blades having a greatest thickness in an area between said first edge and said second edge, the cup affixed to the blade at said greatest thickness. 
     
     
         11 . The at the propeller of  claim 9 , each of said plurality of blades having a curvature, each of said plurality of cups having a curvature corresponding to the respective curvature of the blade. 
     
     
         12 . The propeller  claim 9 , each of said plurality of blades having a radius, the cup positioned in an area corresponding to 80% to 90% of the radius. 
     
     
         13 . The propeller of  claim 9 , each of said plurality of blades having a width dimension between said first edge and said second edge, the cup positioned at a location corresponding to ⅔ of the width dimension from said first edge. 
     
     
         14 . The propeller of  claim 9 , the cup extending outwardly of the back surface of the blade for a distance of between ⅜ inch and ½ inch. 
     
     
         15 . The propeller of  claim 9 , said plurality of blades being rotatable in a forward direction and a rearward direction, said first edge being a leading edge when in said rearward direction, said second edge being a trailing edge when in said rearward direction. 
     
     
         16 . The propeller of  claim 9 , each of said plurality of cups being respectively mechanically affixed to each of said plurality of blades. 
     
     
         17 . A reverse cupping apparatus comprising:
 a blade having a forward surface and a rearward surface, said blade having an outer edge and a first edge and a second edge opposite said first edge, said blade having a radius extending from a hub to said outer edge; and   a cup affixed to said rearward surface of said blade, said cup extending generally longitudinally along said blade, said cup having one end spaced from said outer edge of said blade, said cup being in spaced relation to said first edge and in spaced relation to said second edge, said cup extending for a distance less than a length of said radius.   
     
     
         18 . The reverse cupping apparatus of  claim 17 , said blade having a greatest thickness in an area between said first edge and said second edge, said cup positioned at said greatest thickness. 
     
     
         19 . The reverse cupping apparatus of  claim 17 , said blade having a width dimension between said first edge and said second edge, said cup positioned at a location approximately ⅔ of said width dimension from said first edge. 
     
     
         20 . The reverse cupping apparatus of  claim 17 , said blade having a curvature, said cup having a curvature corresponding to said curvature of said blade.