초록 ▼

A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross sec

A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.

대표청구항 ▼

A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross sec

A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet. her end remote from the leaf spring, to an actuator for tensioning the cable. 16. Prop assembly according to claim 15 in which the actuator is coupled to the closure panel and forms part of a latch assembly for latching the closure panel to the body. 17. Prop assembly according to claim 15 in which said passage is in the form of a through hole. 18. Prop assembly according to claim 15 in which the prop is comprised of a hollow body. 19. Prop assembly according to claim 18 in which the prop is tubular. 20. Prop assembly according to claim 18 in which the prop is formed by bending sheet metal into a U-shaped section. 21. Prop assembly according to claim 15 in which the body has an aperture for slidingly receiving said free end of the prop into a body cavity, the free end of the prop having a stop spaced from said passage for engaging the body when the hood assembly is in a maximum open position. 22. A pair of prop assemblies each made according to claim 15 for coupling to respective sides of a body opening and to said closure panel, each said cable being coupled to a common actuator. 23. A pair of prop assemblies according to claim 22 in which the actuator is coupled to the closure panel and forms part of a latch assembly for latching the closure panel to the body. 24. A prop assembly for temporarily supporting a closure panel in an extended position removed from an opening, the closure panel and a body defining said opening being coupled by a closure hinge, the prop assembly having a rigid elongated prop having a hinged end for coupling to the closure and having a free end remote from said hinged end, movable during opening and closing of the opening, the free end having a passage, a locking pin adapted to be coupled to said body for sliding engagement into said passage, spring biasing means for urging the locking pin into engagement with the prop, a retractor for withdrawing the locking pin away from the prop, the locking pin and retractor being defined by opposite ends of a rigid rod slidingly mountable to the body between a pair of spaced mounting flanges apertured to receive the rod therethrough, and the spring biasing means being in the form of a coiled spring slidingly disposed on said rod for location between one of said mounting flanges remote from the locking pin and a retainer coupled to the rod proximate to the locking pin. 25. Prop assembly according to claim 24 in which the retractor is a bent trailing end portion of the rod. 26. Prop assembly according to claim 24 in which the prop is comprised of a hollow body. 27. Prop assembly according to claim 24 in which the prop is tubular. 28. Prop assembly according to claim 24 in which the prop is formed by bending sheet metal into a U-shaped section. 29. A closure panel hinge and prop assembly for temporarily supporting a closure panel in an extended position removed from an opening, the closure panel hinge having a first hinge bracket for coupling to the closure panel and a second hinge bracket for coupling to a body defining said opening, the prop assembly having a rigid elongated prop hinged at one end to said first hinge bracket and having a free end remote from said hinged end, movable during opening and closing of the opening through respective cooperating apertures formed in said second hinge bracket and the body into a body cavity, the free end of the prop having a passage, the prop assembly further having a locking pin adapted to be coupled to said body for sliding engagement into said passage, spring biasing means for urging the locking pin into engagement with the prop, and a retractor for withdrawing the locking pin away from the prop. 30. Closure hinge and prop assembly according to claim 29 in which the locking pin and retractor are defined by opposite ends of a rigid rod slidingly mountable to the body between a pair of spaced mounting flanges apertured to receive the rod therethrough, and the spring biasing means is in the form of a coiled spring slidingly disposed on said rod for location between one of said mounting flanges remote from the locking pin and a retainer coupled to the rod proximate to the locking pin. 31. Closure hinge and prop assembly according to claim 30 in which said spaced mounting flanges form part of said second hinge bracket. 32. Closure panel hinge and prop assembly according to claim 29 in which the spring biasing means is in the form of a leaf spring coupled to the second hinge bracket and the locking pin is mounted to the leaf spring. 33. Closure panel hinge and prop assembly according to claim 32 in which the retractor comprises a cable coupled to the leaf spring at one end and at another end remote from the leaf spring, to an actuator for tensioning the cable. 34. A pair of closure panel hinge and prop assemblies each made according to claim 33 for coupling to respective sides of a body opening and to said closure panel, each said cable being coupled to a common actuator. 35. Prop assembly according to claim 33 in which the actuator is coupled to the closure panel and forms part of a latch assembly for latching the closure panel to the body. 36. Prop assembly for temporarily supporting a closure panel in an extended position removed from an opening, the closure panel and a body defining said opening being coupled by a closure hinge, the prop assembly having a rigid elongated prop having a hinged end for coupling to the closure and having a free end remote from sad hinged end, movable during opening and closing of the opening, the free end having a passage, a locking pin adapted to be coupled to said body for sliding engagement into said passage, spring biasing mean for urging the locking pin into engagement with the prop, a retractor for withdrawing the locking pin away from the prop, the locking pin and r tractor being defined by opposite ends of a rigid rod slidingly mountable to the body between a pair of spaced mounting flanges apertured to receive the rod therethrough, and the spring biasing means being in the form of a coiled spring slidingly disposed on said rod for location between one of said mounting flanges remote from the locking pin and a retainer comprising a cotter pin slidingly received in a receiving aperture formed in the rod proximate to the locking pin. 37. Prop assembly for temporarily supporting a closure panel in an extended position removed from an opening, the closure panel and a body defining said opening being coupled by a closure hinge, the prop assembly having a rigid elongated pro having a hinged end for coupling to the closure and having a free end remote from said hinged end, movable during opening and closing of the opening, the free end having a passage, a locking pin adapted to be coupled to said body for sliding engagement into said passage, spring biasing means for urging the locking pin into engagement with the prop, a retractor for withdrawing the locking pin away from the prop, the locking pin and retractor being defined by opposite ends of a rigid rod slidingly mountable to the body between a pair of spaced mounting flanges apertured to receive the rod therethrough, the rod having a detent cut into an outer surface of the rod adjacent said locking pin for latching engagement with the prop, and the spring biasing means being in the form of a coiled spring slidingly disposed on said rod for location between one of said mounting flanges remote from the locking pin and a retainer comprising is a cotter pin slidingly received in a receiving aperture formed in the rod proximate to the locking pin. 38. Prop assembly for temporarily supporting a closure panel in an extended position removed from an opening, the closure panel and a body defining said opening being coupled by a closure hinge, the prop assembly having a rigid elongated prop having a hinged end for coupling to the closure and having a free end remove from said hinged end, movable during opening and closing of the o pening, the free end having a passage, a locking pin adapted to be coupled to said body for sliding engagement into said passage, spring biasing mean for urging the locking pin into engagement with the prop, a retractor for withdrawing the locking pin away from the prop, the locking pin and retractor being defined by opposite ends of a rigid rod slidingly mountable to the body between a pair of spaced mounting flanges apertured to receive the rod therethrough, and the spring biasing means being in the form of a coiled spring slidingly disposed on said rod for location between one of said mounting flanges remote from the locking pin and a retainer coupled to the rod proximate to the locking pin, and visual indicator means showing the relative position of the locking pin to the prop and associated with the body, said visual indicator means having at least two adjacent zones of contrasting colour disposed proximate to said retractor. 39. Prop assembly for temporarily supporting a closure panel in an extended position remove from an opening, the closure panel and a body defining said opening being coupled by a closure hinge, the body further having an aperture for slidingly receiving said free end of the prop into a body cavity, the prop assembly having a rigid elongated prop having a hinged end for coupling to the closure and having a free end remove from said hinged end, movable during opening and closing of the opening, the free end having a passage, and a stop spaced from said passage for engaging the body when the hood assembly is in a maximum open position, a locking pin adapted to be coupled to said body for sliding engagement into said passage, spring biasing mean for urging the locking pin away from the prop, the locking pin and retractor being defined by opposite ends of a rigid rod slidingly mountable to the body between a pair of spaced mounting flanges apertured to receive the rod therethrough, and the spring biasing means being in the form of a coiled spring slidingly disposed on said rod for location between one of said mounting flanges remote from the locking pin and a retainer coupled to the rod proximate to the locking pin.