US 12,214,303 B2
Airfoil last chance screen utilizing EDM and AFM
Thomas J. Ocken, Des Moines, IA (US); Murtuza Lokhandwalla, South Windsor, CT (US); Mark J. Kelly, Longmeadow, MA (US); Andrew M. Caldecutt, Vernon, CT (US); Jerry Logsdon, Van Meter, IA (US); Nathan DeVore, Winterset, IA (US); and Joseph Samo, Johnston, IA (US)
Assigned to Collins Engine Nozzles, Inc., Des Moines, IA (US)
Filed by Collins Engine Nozzles, Inc., Des Moines, IA (US)
Filed on Nov. 18, 2022, as Appl. No. 17/990,343.
Prior Publication US 2024/0167423 A1, May 23, 2024
Int. Cl. B01D 29/00 (2006.01); B01D 39/10 (2006.01); B23H 7/02 (2006.01); B23H 7/08 (2006.01); B23H 9/14 (2006.01); B24C 1/08 (2006.01)
CPC B01D 29/0093 (2013.01) [B01D 39/10 (2013.01); B23H 7/08 (2013.01); B23H 9/14 (2013.01); B01D 2201/184 (2013.01); B23H 7/02 (2013.01); B24C 1/083 (2013.01); F05D 2230/12 (2013.01); F05D 2260/607 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of manufacturing a last chance screen for an aircraft engine, the method comprising:
forming an array of holes through a metal sheet with a wire electrode using electrical discharge machining, wherein:
the array of holes comprises a plurality of holes;
each hole of the plurality of holes extends from a first end to a second end; and
each hole is surrounded by one or more wall sections such that the last chance screen is defined by the plurality of holes and the plurality of wall sections;
shaping the first end of each hole by applying a flow of an abrasive flow medium to the array of holes in a first direction, such that the first end of each hole is widened by the flow of the abrasive flow medium and a portion of the wall section adjacent to the first end of each hole has a first convex curvature with respect to the hole; and
shaping the second end of each hole by applying a flow of the abrasive flow medium to the array of holes in a second direction which is opposite to the first direction, such that the second end of each hole is widened by the flow of the abrasive flow medium and a portion of the wall section adjacent to the second end of each hole has a second convex curvature with respect to the hole;
wherein shaping the first end of each hole and shaping the second end of each hole results in an airfoil-shaped cross-section of each wall section.