1
James L Diepenbrock Jr, M Dean Nelsen, Marlyn F Harp: Method of making a cellular core with internal septum. The Boenig Company, Edwin H Crabtree, March 24, 1981: US04257998 (63 worldwide citation)

A method of making a panel for installation in the high velocity air flow region of an engine nacelle and other applications requiring sound absorbing material and increased air frame strength. The panel utilizes a single layer of either a metallic or nonmetallic cellular core with a solid or perfor ...


2
Marlyn F Harp, James L Diepenbrock Jr, M Dean Nelsen: Honeycomb core with internal septum and method of making same. The Boeing Company, Edwin H Crabtree, May 5, 1981: US04265955 (55 worldwide citation)

A sound attenuating panel for installation in the high velocity air flow region of an engine nacelle and/or other applications requiring sound absorbing material. The panel utilizing a single layer of either a metallic or nonmetallic cellular honeycomb core with a solid or perforated septum disposed ...