tangential direction i e as viewed in fig2 noting that each leaf seal segment is oriented generally tangentially with respect to the surface 28 of the rotor the extent of the leaf seal segment in the tangential direction is referred to herein as its tangential length each leaf seal segment also includes a secondary or backing leaf spring segment 30 also attached to the stator 12 in a similar fashion the backing spring segment 30 is located behind or downstream of the primary spring with a more sharply curved portion 32 engaging the backside of the primary spring in a generally tangential fashion referring to fig2 it will be apparent that in order to overlap or shingle the individual leaf seal assemblies without interference the backing spring segments 30 will have a shorter tangential length than the primary springs nevertheless the backing spring will be centered on the primary spring as shown in phantom in fig2 both the primary and secondary spring segments 20 30 are preferably constructed of spring steel the specified alloy composition and the thickness of each dependent on the application the tangential length of the primary springs will depend on the number of segments employed which is again application specific it will be appreciated that the respective effective stiffnesses of spring segments 20 30 may vary based on different degrees of curvature different thicknesses and different alloys this means that the spring stiffness will be non linear thus permitting seal opening and thus performance to be optimized over a wide range of operating conditions a further advantage to the leaf spring seal consisting of chordal segments shingled over each other is that non symmetry.