Month in the Patent Office: A Selection of the More Important Aircraft and Engine Specifications Published Recently

A casing 1 encloses conical chambers 6, 7 and has an end portion 50 enclosing a double frustoconical chamber 52, 53, the space between which and the casing is filled with sound absorbent material such as asbestos or coke, or sheet asbestos may be wrapped round the frusta. The conical passage 53 leads to an eccentric aperture 4 in the base 2 of the chamber 6 and, likewise, the chamber 6 leads to an eccentric aperture in the base of chamber 7. Behind each eccentric aperture is located a deflecting plate 10 comprising two portions 11, 12 of which 11 is inclined to the longitudinal axis of the silencer casing, while the portion 12 is parallel thereto. The deflectors may whirl the gases in the same or in opposite directions. The chamber 52, 53 allows initial expansion of the gases. Specification 366,257 is referred to.