Abstract: The invention relates to a sound-attenuating device for separating off spaces in an aircraft, wherein the device (11) has a screening element (1) which is connected to a supporting means (4) such that it can be moved from a closed state to an open state, and which is designed to at least partially close an opening (12), wherein the screening element (1) comprises a first layer (6) having a sound-reflecting characteristic and a compressible second layer (7) having a sound-absorbing characteristic, which layers are arranged between a first cover layer (8) and a second cover layer (9), wherein the first layer (6), the second layer (7), the first cover layer (8) and the second cover layer (9) are stitched so as to form longitudinal seams (2), along which the screening element (1) can be folded.

Abstract: To reduce sound emission and at the same time improve stability, a multilayer board for acoustic insulation is proposed that includes, but is not limited to a core sheet arranged between a first and a second covering layer. At least one of the two covering layers is of a closed design. The core sheet is firmly connected in a planar fashion to the covering layers. The core sheet comprises slits that extend within the core sheet in the direction of the core sheet thickness, which slits reduce the shear stiffness of the board and thus ensure an improved acoustic insulation effect. On both sides the core sheet comprises continuous edge zones, which extend parallel to the covering layers. An aircraft can have an interior lining formed by panels that comprise the multilayer boards in order to provide acoustic insulation.

Abstract: A device for reducing hydraulic-fluid oscillation in a hydraulic system, in particular in a hydraulic system of an aircraft, wherein the hydraulic system comprises a pump that is driven by a drive, which pump conveys a fluid to a hydraulic line by pressure pulsation. The device comprises an actuator, arranged in the hydraulic line for generating pressure pulsation that compensates for the pressure pulsation of the pump.

Abstract: An insulating mat for the sound insulation of an aircraft fuselage structure that is composed of frames and stringers extending transverse to the frames, to a fastener means for fastening an insulating mat on an aircraft fuselage structure such that acoustic bridges are prevented. An insulating kit is also provided that comprises at least one insulating mat as well as at least one fastener. The insulating mat features a plurality of fastening clips that are fixed on a first surface of the insulating mat and laterally protrude over the border of the insulating mat.

Abstract: The invention relates to a hydro sound damper, in particular for integration in an aircraft hydraulic system, with a throughout inner tube, wherein the inner tube comprises a perforation section which is coaxially encompassed by a housing under formation of a gas-filled cavity. The perforation section is coaxially encompassed by a metal felt cylinder at least in sections and an elastomeric membrane bears on the metal felt cylinder for generating a gas cushion, which is closed in itself. Due to the metal felt cylinder a pushing through of the elastomeric membrane into the bores of the perforation section is avoided when the hydraulic system is depressurized. Furthermore, the metal felt cylinder, which is infiltrated respectively flowed through, produces an improved damping characteristic which might moreover be adjusted by a variation of the flow resistance of the used metal felt.

Abstract: A multilayer board is provided for acoustic insulation and to a method for producing said board. In order to reduce sound emission and at the same time improve stability, a multilayer board for acoustic insulation is proposed that includes, but is not limited to a core sheet, a first covering layer and a second covering layer. At least one of the two covering layers is of a closed design. The core sheet is arranged between the first covering layer and the second covering layer and is firmly connected in a planar fashion to the covering layers. Furthermore, the core sheet comprises slits that extend within the core sheet in the direction of the core sheet thickness, which slits reduce the shear stiffness of the board and thus ensure an improved acoustic insulation effect. On both sides the core sheet comprises continuous edge zones, which extend parallel to the covering layers, in order to, together with the covering layers, ensure the best possible stability of the board.

Abstract: A multilayer board for reducing solid-borne sound radiation with improved mechanical stability when subjected to a load, comprising a first cover layer, a second cover layer, and at least one core layer, wherein the at least one core layer is arranged between the first and the second cover layer, and wherein the at least one core layer comprises at least one first sloped slot.

Abstract: A multilayer board for reducing solid-borne sound radiation with improved mechanical stability when subjected to a load, comprising a first cover layer, a second cover layer, and at least one core layer, wherein the at least one core layer is arranged between the first and the second cover layer, and wherein the at least one core layer comprises at least one first sloped slot.

Abstract: A sound absorbing element, in one example, includes a first wall area, a second wall area as well as a plurality of spring elements. In this arrangement, the first wall area and the second wall area are arranged so as to be spaced apart by a clear space. In one example, the plurality of spring elements are arranged in the clear space and connect the first wall area and the second wall area to each other. By pre-tensioning the plurality of spring elements to a state in which their spring constant approaches zero, significant decoupling between the first and the second wall areas may occur, with accompanying sound noise reduction.

Abstract: A device for reducing hydraulic-fluid oscillation in a hydraulic system, in particular in a hydraulic system of an aircraft, wherein the hydraulic system comprises a pump that is driven by a drive, which pump conveys a fluid to a hydraulic line by pressure pulsation. The device comprises an actuator, arranged in the hydraulic line for generating pressure pulsation that compensates for the pressure pulsation of the pump.

Abstract: The invention relates to a hydro sound damper, in particular for integration in an aircraft hydraulic system, with a throughout inner tube, wherein the inner tube comprises a perforation section which is coaxially encompassed by a housing under formation of a gas-filled cavity. The perforation section is coaxially encompassed by a metal felt cylinder at least in sections and an elastomeric membrane bears on the metal felt cylinder for generating a gas cushion, which is closed in itself. Due to the metal felt cylinder a pushing through of the elastomeric membrane into the bores of the perforation section is avoided when the hydraulic system is depressurized. Furthermore, the metal felt cylinder, which is infiltrated respectively flowed through, produces an improved damping characteristic which might moreover be adjusted by a variation of the flow resistance of the used metal felt.

Abstract: An insulating mat for the sound insulation of an aircraft fuselage structure that is composed of frames and stringers extending transverse to the frames, to a fastener means for fastening an insulating mat on an aircraft fuselage structure such that acoustic bridges are prevented. An insulating kit is also provided that comprises at least one insulating mat as well as at least one fastener. The insulating mat features a plurality of fastening clips that are fixed on a first surface of the insulating mat and laterally protrude over the border of the insulating mat.

Abstract: The present invention relates to a fluid throttle screen for low-noise control of a fluid volume flow rate (Q) in a pipe and the use of such a throttle screen in an aircraft climate control system. In addition, the present invention relates to a climate control system in an aircraft in whose pipe system at least one such throttle screen is installed. The throttle screen according to the present invention comprises multiple friction elements extending longitudinally in the flow direction, which are situated at a distance to one another in such a way that a fluid is throttled continuously over the extension of the fluid throttle screen as a result of friction on the individual friction elements.

Abstract: A sound absorbing element, in one example, includes a first wall area, a second wall area as well as a plurality of spring elements. In this arrangement, the first wall area and the second wall area are arranged so as to be spaced apart by a clear space. In one example, the plurality of spring elements are arranged in the clear space and connect the first wall area and the second wall area to each other. By pre-tensioning the plurality of spring elements to a state in which their spring constant approaches zero, significant decoupling between the first and the second wall areas may occur, with accompanying sound noise reduction.

Abstract: Described is a device for reducing hydraulic fluid oscillations in a hydraulic system, in particular a hydraulic system of an aircraft, with the hydraulic system containing a hose line in which a fluid is conveyed under pressure pulsations, and with the hose line having an inner wall which delimits an inner cross section of the hose line. According to the invention, a line section is provided in the hose line, in which line section is arranged a tube of a predefined length, which tube has an outer cross section which is smaller than the inner cross section of the hose line, with a spacing to the inner wall of the hose line, with a first flow path being formed between the tube and the inner wall of the hose line and a second flow path being formed within the tube, such that mutual cancellation of the hydraulic fluid oscillations of the fluid flowing in the first flow path and the fluid flowing in the second flow path takes place.

Abstract: The acoustic characteristics of lightweight multilayer construction panels have been improved by the formation of three-dimensionally meandering curved slots or rows of slot sections in the core of the panels. The slot depth varies along the length of the curved slots. The slots or rows of slots are spaced from each other by an on-center spacing that is preferably constant along the length of the slots.

Abstract: The acoustic characteristics of lightweight multilayer construction panels have been improved by the formation of three-dimensionally meandering curved slots or rows of slot sections in the core of the panels. The slot depth varies along the length of the curved slots. The slots or rows of slots are spaced from each other by an on-center spacing that is preferably constant along the length of the slots.

Abstract: A wall element has a noise attenuating characteristic and is suitable for use as an aircraft cabin interior panel element that is mounted directly on the aircraft fuselage structure. The wall element includes a rigid lightweight composite panel having a core arranged between two cover layers, and an outer layer arranged adjacent and spaced away from one of the cover layers. The core and the cover layers of the composite panel are air permeable in a direction through the thickness of the panel, while the outer layer is non-air-permeable and is relatively soft and flexible. The outer layer is connected to the composite panel preferably only along the perimeter edge thereof. The non-permeable outer layer faces the aircraft cabin space, while the permeable composite panel is mounted on the fuselage structure. With this structure, acoustic vibrations of the fuselage, to which the wall element is attached, are attenuated and do not result in substantial noise radiation from the outer layer into the cabin.