Jet engine noise attenuator

Claim 1

A JET ENGINE EXHAUST NOISE ATTENUATOR COMPRISING AN OUTER HOUSING HAVING AN INLET OPENING AT ONE END THEREOF AND AN OUTLET OPENING SPACED FROM SAID INLET OPENING, AN INNER CYLINDRICAL SHEET METAL MEMBER DISPOSED COAXIALLY IN RADIALLY SPACED RELATION WITHIN SAID HOUSING WITH ONE END THEREOF DISPOSED ADJACENT SAID INLET OPENING OF SAID HOUSING, A METAL GAS DIFFUSING MEMBER MOUNTED ON THE OTHER END OF SAID INNER MEMBER AND HAVING A PLURALITY OF OPENINGS, SAID INNER MEMBER BEING PROVIDED WITH PERFORATIONS FOR THE DIFFUSION OF GASES RECEIVED THEREIN WITH SAID PERFORATIONS BEING DIMENSIONED TO PROVIDE A PREDETERMINED RANGE OF NOISE FREQUENCIES IN RESPONSE TO PASSAGE OF GASES THERETHROUGH, AND AN IMPERFORATE SHEET METAL CONE HAVING A BASE DIAMETER SUBSTANTIALLY LESS THAN THE DIAMETER OF SAID INNER MEMBER, MEANS MOUTING SAID CONE IN COAXIAL ALIGNMENT WITHIN SAID INNER MEMBER INTERMEDIATE THE ENDS THEREOF WITH THE TIP OF SAID CONE EXTENDING TOWARD BUT TERMINATING SHORT OF SAID ONE END OF THE INNER MEMBER, SAID OUTER HOUSING AND SAID INNER CYLINDRICAL SHEET METAL MEMBER COOPERATING TO DEFINE AN ANNULAR AIR INLET PASSAGEWAY COMMUNICATING WITH SAID INLET OPENING.