Patent ID: 8085895

Claim:
A grid strap for a spacer grid, comprising: an upper plate ( 11 a ) having a dimple ( 12 a ) protruding in one direction from one side of the upper plate ( 11 a ) and an upper base ( 15 a ) extending downwardly from a center of the upper plate ( 11 a ); a pair of symmetrically opposed upper left-hand and upper right-hand supports ( 16 a and 16 b ) branching off downwardly from the upper base ( 15 a ); a lower plate ( 11 b ) having a dimple ( 12 b ) protruding in the one direction and a lower base ( 15 b ) extending upwardly from a center of the lower plate ( 11 b ); a pair of symmetrically opposed lower left-hand and lower right-hand supports ( 16 a and 16 b ) branching off upwardly from the lower base ( 15 b ); a pair of symmetrically opposed bridges ( 18 a and 18 b ) connected to the pair of symmetrically opposed upper left-hand and upper right-hand supports ( 16 a and 16 b ) on one end of each bridge ( 18 a and 18 b ) and the pair of symmetrically opposed lower left-hand and lower right-hand supports ( 16 a and 16 b ) on an opposing end of each bridge ( 18 a and 18 b ); and a conformal curvature ( 17 ) extending from one bridge ( 18 a ) through a center region to the other bridge ( 18 b ), the conformal curvature ( 17 ) having top and bottom edges ( 21 a and 21 b ) defining a distance therebetween, wherein the center region is the midpoint between the bridges ( 18 a and 18 b ) and the distance between the top and bottom edges ( 21 a and 21 b ) being lesser at the midpoint than at the bridges ( 18 a and 18 b ), wherein the conformal curvature ( 17 ) is curved to be concave in the direction opposite to the one direction in which the dimples ( 12 a and 12 b ) protrude, wherein the upper and lower bases ( 15 a and 15 b ), upper left-hand and right-hand supports ( 16 a and 16 b ), lower left-hand and right-hand supports ( 16 a and 16 b ), bridges ( 18 a and 18 b ) and conformal curvature ( 17 ) combine to form a spacer grid spring ( 14 ) protruding in the direction opposite to the one direction in which the dimples ( 12 a and 12 b ) protrude, wherein all the area of the conformal curvature ( 17 ) including top and bottom edges ( 21 a and 21 b ) are configured to contact a fuel rod ( 3 ), wherein the bridges ( 18 a and 18 b ) are curved to be concave in the direction opposite to the one direction in which the dimples ( 12 a and 12 b ) protrude, wherein each bridge ( 18 a and 18 b ) is curved around a lateral axis of the grid strap and configured to be spaced from and parallel to a longitudinal axis of a fuel rod ( 3 ), and wherein the top and bottom edges ( 21 a and 21 b ) are curved to be tapered toward the center region.