Abstract: An acoustic system includes a duct that has a function of causing a fluid to flow therein and has a tubular shape, an internal sound source that is disposed inside the duct on an upstream side or at an outer peripheral portion of the duct, which communicates with an inside of the duct on the upstream side, or an external sound source that is on an outside from an end portion of the duct, and a membrane-shaped member that is formed as a part of a wall of the duct and vibrates in response to sound. A structure including the membrane-shaped member and a rear surface closed space thereof causes acoustic resonance to occur, transmits the acoustic resonance from the sound source into the duct, and suppresses sound radiated from the other end portion of the duct on a downstream side. The external sound source is at a distance within a wavelength at a frequency of the acoustic resonance on the outside from the end portion of the duct.

Abstract: A vibration reducing device is attached to a structure and blocks sound transmitted through the structure. The vibration reducing device includes a unit structure having a target frequency band, the unit structure including a plurality of unit cells, each formed of an acoustic meta-material and having a different target frequency, the unit cells being connected through first bridges; and a predetermined number of unit structures being connected through second bridges and attached to the structure, where each of the unit cells comprises: a mass portion of which a size is set according to the target frequency; a base frame formed as a quadrangular frame, the mass portion being eccentrically disposed in the base frame; and a support portion that connects the mass portion and the base frame, the support portion having a size that is set according to the target frequency.

Abstract: A vibration reduction device having an acoustic meta structure mounted to a vehicle body and configured to block a structure-borne noise transmitted through the vehicle body may include a plurality of unit structures arranged at a predetermined interval therebetween, wherein each of the unit structures includes frame mounted to the vehicle body and configured to separate a predetermined space into a predetermined number of separate sections formed by walls of the frame; and a vibrator formed at a corner portion of each of the separate sections and each of which has a natural frequency to block a vibration transmitted from the vehicle body through the frame.

Abstract: A handlebar for a motor vehicle, in particular a motorcycle or a motorcycle-type vehicle, has a vibration damping mechanism designed to dampen a first vibration of the handlebar. The vibration damping mechanism is designed to detect the first vibration and is equipped with at least one actuator which is effectively coupled to the handlebar in a vibration-transmitting manner and which, in response to the detected first vibration, can be actuated to introduce a second vibration into the handlebar.

Abstract: To prevent overheating of a structural member such as a pivot bulkhead facing a rear side of a fire wall to maintain the temperature of the structural member at allowable temperature or lower. An aircraft of the present invention includes: a fire wall resistant to flame; a structural member facing a rear side of the fire wall; and a skin surrounding the fire wall and the structural member. The structural member includes a guide member and a heat shielding member. The structural member guides, upward, air existing on the rear side of the fire wall, and the heat shielding member shields the guide member from heat radiated by the fire wall.

Abstract: Some embodiments of present disclosure are directed to a micro-perforated glass or glass-ceramics laminate, comprising a first substrate laminated to a second substrate by a first polymer interlayer, wherein the first and the second substrates are independently selected from glass or glass-ceramics, and a plurality of micro-perforations, each of the plurality of micro-perforations extending through the first substrate, the first polymer interlayer, and the second substrate. Some embodiments are directed to methods of forming such micro-perforated glass or glass-ceramics laminates.

Abstract: A unit cell of an artificial phononic crystal for building of an artificial phononic metamaterial, showing reduced mechanical vibrations in a defined frequency range with at least one band gap in the band structure dispersion relation of the unit cell. The unit cell includes at least one building block and at least one mechanical connection connected to the building block, showing reduced mechanical vibrations in a defined frequency range with tailored dispersion properties with at least one band gap is sought. This is accomplished by forming the building block as a toroid, with a central opening and a front surface from which a first multiplicity of struts, which are tiltable relatively to the principal direction, is extending from the front surface. More than one strut is inclined with respect to the principal direction so that a rotation of the toroid around the principal direction is possible.

Abstract: A noise insulating support panel is provided for a structural assembly and includes a base substrate component and at least one localized stiffening reinforcement feature. The reinforcement feature generally extends across the base substrate component in a length direction aligned with, i.e., substantially parallel to, or substantially perpendicular to, a direction of airflow exhibiting turbulent pressure onto the base substrate component. The reinforcement feature cooperates with the base substrate component to minimize energy transmission through the base substrate component. If the base substrate component is a body panel, the reinforcement feature may be a stiffening rib member; if laminated glass, the reinforcement feature is located within an interlayer disposed between glass layers. The interlayer may include a first region including polyvinyl butyral having a first stiffness, and a second region including polyvinyl butyral having a second, lower stiffness.

Abstract: There is provided a soundproof structure that is small and has high soundproofing performance with respect to sound in a low frequency band. At least one soundproof cell including a frame having a hole portion and a film fixed to the frame is provided. The film has a surface density distribution. Assuming that a shortest line segment length between high surface density regions and between the high surface density regions and end portions of the hole portions is ?d, a longest line segment length between the end portions of the hole portions is L [m], a Young's modulus of a material of the low surface density region is E [Gpa], an average film thickness of the low surface density region is h [m], and a maximum surface density and a minimum surface density of the film are ?max and ?min, a parameter X in the following Equation (1) satisfies the following Inequality (2). X=Eh2/(?max/?min)[N]??(1) (?d/L?0.025)/(0.

Abstract: A wing airframe for a wing of a tiltrotor aircraft includes a wing airframe core assembly and a wing skin assembly disposed on the wing airframe core assembly. The wing skin assembly includes an outer skin and a damping sublayer, the damping sublayer interposed between the outer skin and the wing airframe core assembly. The tiltrotor aircraft includes a pylon assembly subject to aeroelastic movement during forward flight. The wing is subject to deflection in response to the aeroelastic movement of the pylon assembly. The damping sublayer reduces the deflection of the wing, thereby stabilizing the wing during forward flight.

Abstract: A power tool having one or more sound damping members which reduce sound and/or vibration from one or more parts of a power tool. The sound damping member can reduce sound and/or vibration from static or dynamic parts of a power tool. The sound damping member can reduce noise and/or vibration from one or more rotating or moving parts of a power tool and its housing or internal structure. Methods, means, controls, systems and practices for reducing or eliminating undesired sound from a power tool are disclosed.

Abstract: A sound and heat insulating blanket is presented comprising: a) a first layer of fabric comprising first fibers; and b) a first sound barrier film comprising a first rubber; wherein the first layer of fabric and first sound barrier film are bound together through a first interpenetrated binding layer wherein the first rubber of the first sound barrier film is interpenetrated by the first fibers of the first layer of fabric; and optionally c) a second layer of fabric comprising second fibers; wherein the second layer of fabric and first sound barrier film are bound together through a second interpenetrated binding layer wherein the first cured composition of the first sound barrier film is interpenetrated by the second fibers of the second layer of fabric. Typically, the sound and heat insulating blanket comprises no adhesive binding the first and second layers of fabric and the sound barrier film.

Abstract: A sound absorption panel (201) is constructed on an acoustically thin sheet (203) to provide an acoustic/vibrational energy absorption metamaterial structure. A plurality of dampers (101) are fixed to the acoustically thin sheet (203), and at least a subset of said dampers (101) comprise a support (103) and a flexible membrane (105) supported by the support. The flexible membrane (105) has one or more masses or platelets (107) attached. The dampers (101) in combination with the sheet (203) result in absorption of energy of movement of the sheet (203) resulting from sound transmission or vibrations across the sheet.

Abstract: An airframe assembly for an aircraft. The airframe assembly includes a first airframe member having a first skin, a second skin, a large cell core joined between the first and second skins and a solid insert having a side surface. The solid insert is joined between the first and second skins such that at least a portion of the side surface is adjacent to the large cell core. The first skin has a first surface disposed opposite the solid insert. The airframe assembly also includes a second airframe member having a second surface. An adhesive joint is disposed between the first and second surfaces structurally bonding the first airframe member to the second airframe member such that the second airframe member is positioned opposite the solid insert.

Abstract: An insulator is implemented such that a lower structure member to be brought into contact with a floor surface allows an upper structure member on which a piano is placed to be suspended through a cantilever spring member and a first wire, and a second wire connects the upper structure member and the lower structure member to each other in the horizontal direction, and the insulator thus functions so as to maintain intrinsic sound generated by the piano by free vibration in pendulum motion using the upper end of the first wire as a pivot, and richness of the sound is enhanced and transmission to a floor surface is inhibited, and, further, vibration caused by a key and a pedal being operated by a performer is reduced by elasticity of the cantilever spring member and the tensile force that acts on any of the second wires, and the performer does not feel uncomfortable with the operation.

Abstract: A multi-layer piezoelectric microactuator assembly has at least one poled and active piezoelectric layer and one poled but inactive piezoelectric layer. The poled but inactive layer acts as a constraining layer in resisting expansion or contract of the first piezoelectric layer thereby reducing or eliminating bending of the assembly as installed in an environment, thereby increasing the effective stroke length of the assembly. Poling only a single layer would induce stresses into the device; hence, polling both piezoelectric layers even though only one layer will be active in use reduces stresses in the device and therefore increases reliability.

Abstract: A laminated structure for use in retrofit building construction (partition, wall, ceiling, floor or door) that exhibits improved acoustical sound proofing characteristics while being optimized for efficient installation. The laminated structure includes a panel with at least one layer of viscoelastic glue, or fire-resistant, viscoelastic glue, which functions both as a glue and an energy dissipating layer. In one embodiment, the laminated structure to be attached to an existing wall in some embodiments includes standard paper-faced gypsum board. In another embodiment the to-be-applied laminated structure includes a cement-based board, and in yet another embodiment the to-be-applied laminated structure includes a cellulose-based board. Once the laminated structure is installed on an existing wall or other partition, the resulting structure greatly attenuates transmitted noise and minimizes the labor required for installation and finishing.

Abstract: An apparatus comprises a movable section for sound generation; at least one actuator configured to actuate the movable section, the actuator being in communication with electronic circuitry and configured to generate an acoustic signal substantially from the movable section when the at least one actuator is driven by an audio signal; and a back cover coupled to the movable section and configured to limit the generation of sound from the back cover by attenuating vibrations that are caused when the movable section is actuated by the at least one actuator. The movable section and the at least one actuator define a panel speaker.

Abstract: A description is given of a method for the sound damping and/or sound insulation of metallic parts and/or plastic parts in which thermoplastic compounds are applied to the parts as a defined profile by direct extrusion at melting temperatures of between 120 and 300° C., wherein, before the heating, the compounds are in the form of granules with a density of 1.5 to 5 g/cm3.

Abstract: Examples described herein relate to systems, apparatuses, and methods for a microphone device that includes a microphone configured to output sound data signals, a first circuit board configured to perform audio analytics on the sound data signals, a second circuit board configured to extract power for powering the first circuit board, a housing configured to contain the microphone, the first circuit board, and the second circuit board, and an Ethernet interface configured to connect the second circuit board to a security system through an Ethernet connection.

Abstract: Composite acoustic panels are provided which may usefully be employed for aircraft interior panel assemblies. The composite acoustic panels may include a core member defining opposed surfaces, and a pair of exterior face sheets each attached to a respective one of the opposed surfaces of the core member. At least one of the face sheets may be microperforated. The core member comprises an adjacent plurality of tubular channels extending through a thickness dimension of the core member between the opposed surfaces thereof, while predetermined adjacent ones of the tubular channels are filled with a material to define a series of filled tubular channels which are adjacent to a region of open tubular channels. Certain ones of the open tubular channels may be partially filled with an acoustic dampening material. Discontinuous viscoelastic layers may be positioned so as to overlay central regions of the adjacent plurality of the open tubular channels which are bounded by an array of the filled tubular channels.

Abstract: A vibration dampening device is operable to dampen vibrations within ropes of an elevator car or other components to improve ride quality, and is further operable to harness or harvest and convert energy from those vibrations into electrical energy. The dampening device includes a macro-fiber composite and the vibrations are communicated or transmitted to the macro-fiber composite. The macro-fiber composite is operable to harness or harvest and convert energy from vibrations into electrical energy. Such electrical energy is communicated or transmitted to a control system of the elevator car for storage and/or use.

Abstract: There are provided a detector and the like that are capable of conveniently detecting conductor or a circuit including a coil. The detector includes a detecting section that determines a Q value or a degree of variation thereof in a circuit including a coil capable of electromagnetic coupling with an external object and that performs detection concerning a state of the electromagnetic coupling with the external object based on a determined result.

Abstract: An integrated fiber cement and foam cladding system is provided that incorporates foam or similar light weight material to improve the insulation capacity of the cladding system. The system includes at least a fiber cement layer and a foam layer disposed on the backside of the fiber cement layer. The system improves the R-value of the building, a measure of the building's resistance to transferring heat or thermal energy.

Abstract: A transportation vehicle part that includes: a patch member constructed of a plate-like metal patch panel, and a vibration attenuating resin layer provided along a surface of the patch panel; and a metal base plate closely adhered with the vibration attenuating resin layer of the patch member and affixed with the patch member; according to this configuration, the transportation vehicle part which has a superior vibration characteristic without greatly increasing the thickness and the weight of the transportation vehicle part is provided.

Abstract: An integrated fiber cement and foam cladding system is provided that incorporates foam or similar light weight material to improve the insulation capacity of the cladding system. The system includes at least a fiber cement layer and a foam layer disposed on the backside of the fiber cement layer. The system improves the R-value of the building, a measure of the building's resistance to transferring heat or thermal energy.

Abstract: A sound absorbing metamaterial comprises an acoustic impedance-matched surface configured to minimize reflection from an incident acoustic wave. The surface is comprised of an elastic or flexible membrane and a substantially rigid mass mounted on the membrane. A relatively solid surface is provided as a reflective surface and is positioned behind the membrane. The reflective surface is separated by a predetermined distance from the elastic or flexible membrane and forms a fluid space between the membrane and the solid surface. The mass mounted on the membrane, in combination with the elastic membrane establish a plurality of eigenfrequencies.

Abstract: A sealing element (10) of a deformable material for sealing an opening in a wall (16), which separates two different chambers, comprises at least one aperture (12) which is arranged in a sealing first region (20) and is designed to receive a tube (14), and a yielding second region (24) which is designed to be pressed against the wall (16), wherein the second region (24) is differentiated from the first region (20) at least in part by an indentation (22).

Abstract: A food waste disposal includes a grinding part configured to grind food waste, a dewatering part configured to receive the ground food waste from the grinding part and to discharge water out of the received food waste, and a connecting frame having a rotating shaft. The dewatering part is rotatably coupled to the connecting frame via the rotating shaft. Further, the dewatering part is configured to be rotated vertically downward away from the grinding part in a top/bottom direction around the rotating shaft.

Abstract: Method of manufacturing bond panels and bond panel assemblies are provided. In various embodiments, the method may comprise laying up a top skin on a tool comprising a mandrel. The method may further comprise laying out core on the top skin. The method may further comprise laying up back skin to create an assembly. The assembly may comprise the top skin, the core, and the back skin. The method may further comprise placing the assembly in a bag to provide a bagged assembly. The method may also comprise placing the bagged assembly in an autoclave. The method may further comprise subjecting the bagged assembly to a pressure and a temperature for a determined amount of time. In this regard, the back skin, the core, and the top skin may be co-cured in a single autoclave pressurization and heating operation.

Abstract: A panel assembly includes a first panel defining a surface, and a boom attenuation panel. The boom attenuation panel includes a circumferential edge, and a central portion. The boom attenuation panel is attached to the surface of the first panel, along the circumferential edge of the boom attenuation panel. The central portion of the boom attenuation panel is spaced from the surface of the first panel a gap distance to form a gas chamber between the surface of the first panel and the central portion of the boom attenuation panel. The gas chamber contains a gas that is moveable within the gas chamber in response to wave-like motion of the first panel. Movement of the gas increases the effective acoustic mass of the boom attenuation panel, and damped the wave-like motion of the first panel, which operates to reduce noise generated from the wave-like motion of the first panel.

Abstract: A panel with pattern block bead for a car body includes a plurality of beads. The panel is divided into four division panels by a first substantially horizontal reference line and a first substantially vertical reference line each passing through a center of the panel. One of the beads is formed at a center of each of the division panels.

Abstract: The present invention relates to a method for molding a substantially improved heat-resistant sound absorbing and insulating material, which uses a sound absorbing material containing, based on 100 parts by weight of the sound absorbing material, an amount of about 20-80 parts by weight of a fiber material having a limiting oxygen index (LOI) of about 25% or greater and a heat resistance temperature of about 200° C. or greater and an amount of about 20-80 parts by weight of a thermosetting binder resin having a heat resistance temperature of about 200° C. or greater and is installed on an engine cylinder block and an automotive body panel above a muffler of a vehicle. The method includes: a releasing agent coating step of coating a releasing agent inside a heated die; a heated compression molding step of fixing a shape; and a cold compression step of stabilizing the shape.

Abstract: According to one embodiment, a method of damping an actuator to reduce an amplitude of a resonance peak of the actuator, including a piezoelectric element and a translation mechanism, includes securing one surface of a restraint member having at least two surfaces to a movable part of the translation mechanism with an elastic or viscoelastic body therebetween, securing the other surface of the restraint member to a support portion of the translation mechanism with an elastic or viscoelastic body therebetween, and converting vibration energy of the movable part into thermal energy, based on distortion caused by deformation of the elastic or viscoelastic body.

Abstract: An electrical outlet box acoustic seal includes a seal body formed from a flexible sound suppressing material. The seal body has a front side, a rear side, and a peripheral edge. A seal rear projection extends from the seal rear side. The seal rear projection is configured to wrap around a front peripheral edge of an electrical outlet box having left and right sides, top and bottom sides, a rear side, and an open front defined by the outlet box front peripheral edge that provides access to an outlet box interior. When the outlet box is mounted in an opening formed in an architectural separation, and when the acoustic seal is installed on the outlet box, the seal rear projection inserts into a gap between the outlet box front peripheral edge and the opening of the architectural separation to assist in blocking noise transmission through the gap.

Abstract: A sound absorbing structure comprising a set of nesting components having increasing size, each of said components being enclosed by the next larger said component, each of said components and its next larger component defining an aperture and a cavity, and said apertures and said cavities forming a set of Helmholtz resonators having increasing size, dissipating sound energy over a wide frequency range.

Abstract: A vibration reduction device includes: an elastic body; a dynamic mass; and a controllable mass. The dynamic mass is supported by an object of vibration reduction through the elastic body. An actuator causes the controllable mass to move with respect to the dynamic mass. Such a vibration reduction device can vary the frequency and the amplitude at which the dynamic mass vibrates with respect to the object of vibration reduction by causing the controllable mass to move appropriately with respect to the dynamic mass, thereby enabling vibration of the object of vibration reduction to be reduced more reliably. In addition, such a vibration reduction device can reduce vibration of a certain frequency of the object of vibration reduction even when the controllable mass is fixed with respect to the dynamic mass.

Abstract: A compact vibration reducing apparatus includes a dynamic mass; elastic member which apply elastic force to the dynamic mass so that the dynamic mass vibrates in a parallel to a vibration damping direction; a control mass; an actuator which move in parallel to a length change direction; and a motion direction converting mechanism which moves the control mass to the dynamic mass so that the control mass moves in a vibration damping direction to the dynamic mass through the operation of the actuator. The actuator is supported by the dynamic mass so that the operation direction of the actuator is not parallel to the vibration damping direction.

Abstract: An apparatus comprises a first portion comprising a generally flexible material formed in a generally planar rectangular shape. A second portion comprises the generally flexible material formed in the generally planar rectangular shape. The first portion and the second portion are joined to form a V-shaped structure. The first portion and the second portion are configured to be joinable to a surface of at least one structure for damping an applied external force.

Abstract: A self-supporting acoustic insulation panel (1) comprising a visible wall (3) that is not self-supporting and an invisible wall (2) that is not self-supporting facing a source (50) of soundwaves. A porous core (20) is arranged between the visible wall (3) and the invisible wall (2), a plurality of link elements (5) each extending from the invisible wall (2) towards the visible wall (3), each link element (5) passing through an orifice (21) in said core (20) and being connected to the visible wall (3) and to the invisible wall (2), each link element (5) separating the visible wall (3) from the invisible wall (2) and mechanically linking the visible wall (3) with the invisible wall (2) while acoustically decoupling the visible wall (3) from the invisible wall (2).

Abstract: An interlayer film for a laminated glass provides excellent vibration damping performance at high temperature and excellent sound insulation in a wide temperature range. The interlayer film comprises a part A containing a resin composition A or a resin A and a part B containing a resin composition B or a resin B, and the part A and the part B are horizontally arranged. The interlayer film for a laminated glass has a difference between temperatures Ta and Tb of 10° C. or larger when the temperature Ta is a temperature at which the resin composition A or the resin A shows a maximum loss tangent of a dynamic viscoelasticity at a frequency of 1 Hz, and the temperature Tb is a temperature at which the resin composition B or the resin B shows a maximum loss tangent of a dynamic viscoelasticity at a frequency of 1 Hz.

Abstract: At least three processing machines are positioned on a supporting structure including a plurality of beams spaced apart from each other. The at least three processing machines include a first processing machine, a second processing machine supported by at least one of beams which support the first processing machine, and a third processing machine supported by beams different from all the beams which support the first processing machine. A distance between the first processing machine and the second processing machine, at which an amount of vibration transferred from the first processing machine to the second processing machine becomes smaller than a predetermined amount, is determined, thereby positioning the first processing machine and the second processing machine with a distance not less than the determined distance.

Abstract: Metamaterial members for absorbing sound and pressure, and modular systems built of metamaterial members are provided. The metamaterial member includes an outer mass. The outer mass can have a cavity formed therein in which a stem coupled to an inner mass is disposed, or the outer mass can be solid and contain an inner mass embedded therein. The inner mass can include an inner core and an outer shell. Multiple metamaterial members can be attached to form a modular system for absorption of sound and pressure.

Abstract: A low profile, wrappable spacer and method for maintaining a pair of elongate members in fixed, spaced relation to one another is provided. The wrappable spacer includes a flexible elongate body having oppositely facing inner and outer faces extending along laterally spaced, lengthwise extending edges between opposite ends. The inner face has an adhesive surface. At least one member extends between the edges transversely to the lengthwise extending edges. The member extends outwardly from the adhesive surface, wherein the adhesive surface is configured for adhesion to at least one of the member, the elongate members or the outer face.

Abstract: A multi-layer assembly, such as a sound damping metal laminate used in the automotive industry, having first and second rigid layers and an adhesive layer in between. A retention feature in the form of a raised embossment may be formed in one or more of the rigid layers and may be located near a fastening hole, which accommodates a nut and bolt or some other type of fastening device. The retention feature may impart rigidity and improved stiffness to the multi-layer assembly in the area surrounding the fastening hole, and it may also create a space between the rigid layers that is generally devoid of adhesive from the adhesive layer. This, in turn, can improve the long term performance of the multi-layer assembly by addressing issues such as compression set, spring back and/or stress relaxation. Methods of manufacture and other embodiments are also provided, including ones that accommodate multiple fastening holes, have discontinuous retention features, and use welds in place of nuts and bolts, to name a few.

Abstract: A drive system includes multiple vibrating members that tend to vibrate when these members are driven and a holding system to hold the multiple vibrating members. The holding system at least includes a first holding unit and a second holding unit superimposed on and partially connected to each other. The multiple vibrating members include a first vibrating member and a second vibrating member. The first vibrating member is held by the first holding unit and is not held by the second holding unit. The second vibrating member is held by the second holding unit and is not held by the first holding unit. At least one of the first vibrating member and the second vibrating member is a driving device to drive another member as a drive source.

Abstract: A wheel assembly for a vehicle includes a rim having a noise suppression device. The rim includes an outer radial surface that is concentrically disposed about a central axis. A tire is mounted to the rim to define a tire cavity between the outer radial surface of the rim and an interior surface of the tire. The noise suppression device includes a device wall that defines at least one resonator chamber, and includes a plurality of apertures allowing fluid communication between the tire cavity and the resonator chamber, with each of the plurality of apertures defining an opening area between the range of 0.03 mm2 and 0.8 mm2.

Abstract: A method for forming a propshaft assembly. The method includes: providing a hollow shaft; tuning a mass and a stiffness of at least one liner to form an intermediate damper, the intermediate damper being configured to attenuate at least one of a bending moment vibration and a torsion mode vibration that occurs at a first predetermined frequency; tuning the intermediate damper to form a tuned damper, the tuned damper attenuating the at least one of the bending moment vibration and the torsion mode vibration at the first predetermined frequency and also attenuating shell mode vibration; and installing the tuned damper into the hollow shaft.

Abstract: An end cap for an arc spring in a torsional vibration damper having a cylindrical section for engaging with the arc spring and a radial section at one end of the cylindrical section for engaging with an input or output side of the torsional vibration damper, the end cap being producible by shaping from a metal sheet. A torsional vibration damper for elastic transmission of torque between an input side and an output side including the described end cap for transmission of force between one of the sides and the arc spring.

Abstract: A vibration damped enclosure comprises side walls and a vibration damping plate structure which extends across the enclosure and is attached to internal surface portions of a first and a second side walls. The vibration damping plate structure (2) comprises a non-rigid layer (12) sandwiched between two rigid layers (13, 14), wherein each rigid layer between the first and second side walls (5, 6) comprises at least one cut (15, 16) through the rigid layer (13, 14) which makes the extension of each rigid layer between the first and second sidewalls (5, 6) discontinuous.