Shroud for aircraft duct

Claim 1

An apparatus comprising a duct for use in aircraft, a shroud mounted on said duct, said shroud comprising an axially extending tube, the surface of said tube having at least one clamping band receiving groove formed therein, said groove having a radially inwardly spaced base, said base having a plurality of radially inwardly projecting angularly spaced arcuate projections defining spacers, a band formed from a heat resistant rubber-like material secured to the outer surface of the duct beneath said clamping band receiving groove, said spacers engaging the outer surface of said band for holding said shroud in a radially outwardly spaced relationship to said duct, defining thereby an insulating air gap between the duct and the shroud and isolating said shroud from aircraft vibration and heat in the duct, the portions of the base of the groove between said arcuate projections defining channels beneath said clamping band receiving groove for the passage of gases in the air gap between the outer surface of the duct and the inner surface of the shroud.

Claim 2

An apparatus comprising a duct for use in aircraft, a shroud mounted on said duct, said shroud comprising an axially extending tube, the surface of said tube having at least one clamping band receiving groove formed therein, said groove having a radially inwardly spaced base, said base having a plurality of radially inwardly projecting angularly spaced arcuate projections defining spacers, a band formed from a heat resistant rubber-like material secured to the outer surface of the duct beneath said clamping band receiving groove, said spacers engaging the outer surface of said band for holding said shroud in a radially outwardly spaced relationship to said duct, defining thereby an insulating air gap between the duct and the shroud and isolating said shroud from aircraft vibration and heat in the duct, the portions of the base of the groove between said arcuate projections defining channels beneath said clamping band receiving groove for the passage of gases in the air gap between the outer surface of the duct and the inner surface of the shroud.

Claim 7

An apparatus comprising a duct for use in aircraft, a shroud mounted on said duct, said shroud comprising a generally cylindrical resilient tube formed from an organic aramid fiber, said tube being slit along its entire length whereby adjacent edges of the slit can be pulled apart so the tube can be mounted on a duct, at least one radially inwardly extending clamping band receiving groove situated transverse to the axis of a tube, said groove including a base which is radially inwardly spaced from the circumferential periphery of said tube, said base adapted to receive a clamping band whereby the tube can be clamped to a duct, said base of said groove having a plurality of radially inwardly projecting angularly spaced arcuate projections defining spacers, a band formed from a heat resistant rubber-like material secured to the outer surface of the duct beneath said clamping band receiving groove, said spacers engaging the outer surface of said band for holding said shroud in a radially outwardly spaced relationship to said duct defining thereby an insulating air gap between the duct and the shroud and isolating said shroud from aircraft vibration and heat in the duct, the portions of the base of the groove between said arcuate projections defining channels beneath said clamping band receiving groove for the passage of gases in the air gap between the outer surface of the duct and the inner surface of said shroud, and a plurality of heat detectors in fixed relationship to said shroud mounted along the length of said air gap and communicating therewith whereby hot gas leaks in the duct can be detected.

Claim 8

An apparatus comprising a duct for use in aircraft, a shroud mounted on said duct, said shroud comprising a generally cylindrical resilient tube formed from an organic aramid fiber, said tube being slit along its entire length whereby adjacent edges of the slit can be pulled apart so the tube can be mounted on a duct, at least one radially inwardly extending clamping band receiving groove situated transverse to the axis of a tube, said groove including a base which is radially inwardly spaced from the circumferential periphery of said tube, said base adapted to receive a clamping band whereby the tube can be clamped to a duct, said base of said groove having a plurality of radially inwardly projecting angularly spaced arcuate projections defining spacers, a band formed from a heat resistant rubber-like material secured to the outer surface of the duct beneath said clamping band receiving groove, said spacers engaging the outer surface of said band for holding said shroud in a radially outwardly spaced relationship to said duct defining thereby an insulating air gap between the duct and the shroud and isolating said shroud from aircraft vibration and heat in the duct, the portions of the base of the groove between said arcuate projections defining channels beneath said clamping band receiving groove for the passage of gases in the air gap between the outer surface of the duct and the inner surface of said shroud, and a plurality of heat detectors in fixed relationship to said shroud mounted along the length of said air gap and communicating therewith whereby hot gas leaks in the duct can be detected.