Airfoil with energy absorbing edge guard

Abstract

An edge guard apparatus for an airfoil includes: a body having a nose with spaced-apart first and second wings extending therefrom, the body defining a cavity between the first and second wings; and an energy absorbing structure disposed in the cavity.

What is claimed is: 
     
         1 . An edge guard apparatus for an airfoil, comprising:
 a body having a nose with spaced-apart first and second wings extending therefrom, the body defining a cavity between the first and second wings; and   an energy absorbing structure disposed in the cavity.   
     
     
         2 . The apparatus of  claim 1  wherein the energy absorbing structure comprises a cellular structure. 
     
     
         3 . The apparatus of  claim 1  wherein the energy absorbing structure comprises a plurality of tubes arranged in a side-by-side configuration. 
     
     
         4 . The apparatus of  claim 2  wherein the tubes extend in a spanwise direction of the body. 
     
     
         5 . The apparatus of  claim 3  wherein at least one of the tubes extends over only a portion of a span of the body. 
     
     
         6 . The apparatus of  claim 3  wherein a greater number of tubes are disposed near a first end of the body and a fewer number of tubes are disposed near a second end of the body. 
     
     
         7 . The apparatus of  claim 3  where at least one of the tubes is bonded to another one of the tubes. 
     
     
         8 . The apparatus of  claim 3  wherein the tubes are separated by voids, the voids being filled with an adhesive. 
     
     
         9 . The apparatus of  claim 3  wherein the tubes comprise a metal alloy. 
     
     
         10 . The apparatus of  claim 1  wherein the body comprises a sheet stock material. 
     
     
         11 . An airfoil apparatus, comprising:
 an airfoil having convex and concave sides extending between a leading edge and a trailing edge;   a body having a nose with spaced-apart first and second wings extending therefrom, the body defining, in cooperation with the leading edge of the airfoil, a cavity; and   an energy absorbing structure disposed in the cavity.   
     
     
         12 . The apparatus of  claim 11  wherein the energy absorbing structure comprises a cellular structure. 
     
     
         13 . The apparatus of  claim 11  wherein the energy absorbing structure comprises a plurality of tubes arranged in a side-by-side configuration. 
     
     
         14 . The apparatus of  claim 12  wherein the tubes extend in a spanwise direction of the airfoil. 
     
     
         15 . The apparatus of  claim 13  wherein at least one of the tubes extends over only a portion of a span of the airfoil. 
     
     
         16 . The apparatus of  claim 13  wherein a greater number of tubes are disposed near a tip of the airfoil and a fewer number of tubes are disposed near a root of the airfoil. 
     
     
         17 . The apparatus of  claim 13  where at least one of the tubes is bonded to another one of the tubes. 
     
     
         18 . The apparatus of  claim 13  wherein the tubes are separated by voids, the voids being filled with an adhesive. 
     
     
         19 . The apparatus of  claim 13  wherein the airfoil comprises a composite material and at least one of the body and the tubes comprise a metal alloy.