Abstract: A passive distributed vibration absorber that utilizes multiple discrete mass elements and a viscoelastic layer and that effectively attenuates vibration in modally dense structures excited by a broadband input noise excitation and is tunable to multiple natural frequencies in such modally dense vibrating structures including low frequencies

Abstract: There is provided a structure of a vibration insulating member for firmly fixing the member between a fuel tank mounted on a vehicle body by means of a tank band and the vehicle body. The vibration insulating member includes an engaging protrusion that is fixed to a fixing hole that is made through the vehicle body in a direction orthogonal to a direction in which the tank band is fastened.

Abstract: A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

Abstract: A suspension system for use in a laundry washing machine to suspend a tub assembly from a base portion of a cabinet. The suspension system includes a support frame interconnected to an outer tub of the tub assembly and a plurality of isolation damper units for resiliently coupling the support frame to the base portion of the cabinet. The isolation damper units function to allow limited lateral movement of the tub assembly relative to the cabinet while also providing a “return to center” feature. The isolation damper units are further operable to inhibit rotation of the outer tub relative to the cabinet. Finally, the isolation damper units function to absorb the vibration transmitted through the tub assembly to the support frame so as to minimize transmission of such vibration to the cabinet.

Abstract: The invention provides a transportation device having a shock absorbing device with a reduced non-collapse region. Shock absorbers 14 and 17 constituting a shock absorbing device 10A provided on a transportation device is connected respectively to shock absorbers 17 and 20 disposed rearward therefrom via connecting members 23 and 26 having ashtray-like cross-sectional shapes. The shock absorber 20 disposed at the rearmost position is connected via welding to a base 29. Collapse regions 15, 18 and 21 of the shock absorbers 14, 17 and 20 are collapsed by the load applied to the shock absorbers 14, 17 and 20, and their lengths are shortened. Non-collapse regions 16 and 19 of the shock absorbers 14 and 17 overlap respectively with the non-collapse regions 19 and 22 of the shock absorbers 17 and 20 disposed rearward therefrom.

Abstract: An elastomeric tie rod end isolator or an elastomeric cartridge isolator that includes an outer metal sleeve defining a generally cylindrical socket, a generally cylindrical inner metal sleeve disposed coaxially within the socket in radially spaced relationship with the outer metal sleeve, and an elastomeric isolator disposed therebetween. The elastomeric isolator is a unitary annular body formed of an elastomer material and having a radially inboard surface in contact with the inner metal sleeve and a radially outboard surface in contact with the outer metal sleeve. The unitary elastomer body has a generally conical primary load-carrying section and a generally cylindrical secondary load-limiting section, each disposed coaxially about the axis of the socket. The load-limiting section includes a snubber gap formed by an axially extending groove.

Abstract: A magnetorheological damper device is provided having an increased shear interface area per unit volume of the device, which enhances the stroking force of the damper. The damper generally includes a cylindrically shaped housing; a magnetorheological fluid disposed in the cylindrically shaped housing; a piston assembly disposed within the cylindrically shaped housing in sliding engagement with the cylindrically shaped housing defining a first chamber and a second chamber, wherein the piston assembly comprises a plurality of cylindrically shaped fluid passageways extending from the first chamber to the second chamber, and an electromagnet; and a power supply in electrical communication with the electromagnet.

Abstract: An impact absorber for a vehicle includes an outer body including a cavity having an axis, and an inner body situated partially within the cavity for relative movement into the cavity when the absorber is subjected to an impact. The inner body has at least one lateral protrusion. A number of deformable units are located in the outer body at different positions along the cavity. The deformable units partially protrude into the cavity for successive engagements and deformations, one unit after another unit, along the cavity, by the protrusion of the inner body moving into the outer body, thereby absorbing the energy of an impact in different stages. Each deformable unit includes a rigid ball protruding into the cavity and a deformable plate fixed behind the ball.

Abstract: A mass damping system for use in all temperature ranges, including extreme temperature environments, is provided. The system comprises a housing having bottom, side and end walls, and an inner peripheral surface that defines an interior, a mounting mechanism located on the housing, configured to mount the housing to the mass, and macro-particles disposed within the housing interior able to flow within the housing and simulate a liquid.

Abstract: Methods and apparatus are provided for locking and releasing ends of a support strut coupled between a mounting platform and a load. In a preferred embodiment, the strut comprises a damping section coupled between the ends and having a gap therein when the strut is unlocked, a locking section coupled between the ends for closing the gap by applying stress to a portion of the damper section through a force transmitting member, and a releasing section coupled in parallel with part of the force transmitting member, the releasing section including a Shape Memory Alloy (SMA) and heater therefore. Heating the SMA relieves the stress and opens the gap. Release from the locked condition occurs gradually and without fracture or sudden shock and the heater can be actuated remotely. In a preferred embodiment, a worm drive turnbuckle arrangement is used to apply force to lock the strut.

Abstract: A lid adapted to be mounted on the cylinder head of an internal combustion engine by attachment screws includes a cap and a carrier element adapted to be attached to the cylinder head by the attachment screws. To achieve an improved sound decoupling, the cap and the carrier element are connected to an elastomer component, with the connection between the cap and the carrier element being, at least in part, exclusively constructed by the elastomer component, and with a space being provided between the cap and the carrier element. The carrier element possesses a substantially straight section arranged to extending preferably at a right angle to the attachment surface of the cylinder head, the substantially straight section of the carrier element, a portion of the elastomer component adjacent the cap, and a portion of the cap adjacent the carrier element extend in a straight line.

Abstract: A friction vibration damper for damping the vibrations of a vibrating component comprising a body, a chamber and a plurality of elements, the body defines the chamber which is partially filled with the plurality of elements, the friction vibration damper, in use, disposed on or in the vibrating component characterized in that the friction vibration damper is configured to substantially prevent the elements operationally moving in a convection-like flow pattern.

Abstract: In a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing, a vibration propagation between the vane member and the casing is prevented or restrained, and a vibration of a pipe extending from the casing is absorbed.

Abstract: Vibration damping device for vehicles includes: a rigid housing member having an accommodation space and fixed to a vibrative member; and an independent mass member having a rigid mass body and an elastic body layer bonded on the outer surface of the rigid mass body. The independent mass member is non-adhesively disposed in the accommodation space such that an outer surface of the independent mass member is opposed to the inner surface of the housing member with a predetermined gap distance therebetween, to thereby permit displacement of the independent mass member relative to the housing member. The independent mass member and the housing member is brought into elastic impact against each other at respective abutting surfaces thereof in at least one vibrational input direction. The elastic body layer has a spherical outer surface so as to facilitate bouncing displacement of the independent mass member within the accommodation space.

Abstract: A spacecraft isolator including shape memory alloy components that are electronically heated to unlock the isolator. The isolator can be manually unlocked with an adjustment bolt.

Abstract: Fluid current induced vibrations, as well as vortex shedding vibrations induced in a cable stay or a similar elongated, cylindrical element are dampened and substantially eliminated by applying a plurality of flexible active or passive damper bands to the cable at spaced intervals. In underwater currents, the damper bands force or channel the fluid flow over a circular cross-sectional shape, which inhibits lift, and therefore damps the cable stay oscillations. These damper bands can be retrofit to existing cables or can be installed on new cables. Each damper band may include a shiftable mass and an energizing device for facilitating assisted shifting of the mass. A control assembly can actuate all or selected ones of the energizing devices in response to sensed magnitudes of cable stay vibration.

Abstract: A suspension damper including a tube and a damping piston assembly disposed within the tube and slidably mounted therein for reciprocal movement in the tube. The suspension damper also includes a piston rod extending through the tube and connected to the damping piston assembly, a rod guide assembly closing a top end of the tube, and a rebound cut-off disk and spring suspended in the tube between the rod guide assembly and the damping piston assembly and cooperating with the damping piston assembly to provide a rebound cut-off effect between the rebound cut-off disk and the damping piston assembly. The rebound cut-off disk and spring have specific gravities that are less than the specific gravity of the fluid in the tube, such that the disk and the spring are floatable in the fluid.

Abstract: A steering column damper for a power-driven vehicle comprises a jacket tube with a central longitudinal axis; a sliding tube displaceably guided in the jacket tube; a steering shaft, which is mounted for pivotability about the central longitudinal axis relative to the sliding tube and/or the jacket tube and guided through the jacket tube and the sliding tube; at least one working area, which is disposed between the jacket tube and the sliding tube and filled with a damping medium; at least one working-area-volume reduction unit, which is connected with the sliding tube, reducing the volume of the at least one working area upon insertion of the sliding tube into the jacket tube; at least one aperture which opens the at least one working area to ambience for discharge of the damping medium from the respective working area; a closing element for blocking the at least one aperture; and a triggering unit for controllable release of the respective closing element.

Abstract: The invention relates to a shock absorber having high dissipating power and comprising a rod-and-piston assembly (12) slidably received in a cylinder (11) and defining on either side of the piston (13) respective working chambers (18; 19) containing hydraulic fluid. In the invention, each working chamber (18, 19) communicates continuously with an associated chamber (20, 21) containing a heterogeneous energy absorption-dissipation structure constituted by a capillo-porous matrix (51, 61) and an associated liquid (52, 62) relative to which the matrix is lyophobic. In addition, each working chamber (18, 19) communicates with a common compensation chamber (30) via an associated valve system (32, 33) including non-return means (40, 41) ensuring that the working chamber concerned closes automatically during compression, and opens during expansion.

Abstract: A circular cylindrical container having sealed ends provides a device for dissipating mechanical forces. The container is filled with particulate material and has circular wheel-like structures having rims and spokes located in the interior of the container in which the rim circumferences of the wheel-like structures increase as they are located further and further away from the centroid of the container along the elongated axis of the container toward one of the sealed ends.

Abstract: A circular cylindrical container having sealed ends provides a device for dissipating mechanical forces. The container is filled with particulate material and has circular wheel-like structures having rims and spokes located in the interior of the container in which the rim circumferences of the wheel-like structures increase as they are located further and further away from the centroid of the container along the elongated axis of the container toward one of the sealed ends.

Abstract: The invention concerns a launch vehicle comprising a shroud (1a, 5a) supporting auxiliary propellers (2, 3) applying in operation excess flow of stresses to the shroud (1a, 5a), said device comprising means for coupling the payload (4) with the launch vehicle shroud. The invention is characterized in that the coupling means are designed to ensure a mechanical coupling between the payload (4) and the shroud along the direction of the launch vehicle longitudinal axis (X), and to cause them to be disengaged along radial and tangential directions. The invention is useful for neutralizing the effects on the payload of excess stresses applied on the launch vehicle shroud by the auxiliary propellers (2, 3).

Abstract: A damping system is disclosed which includes a housing that receives vibrations, a mounting platform movably disposed with respect to the housing, at least one bearing surface on or attached to one of the housing and the platform, and at least one frictional member on or attached to the other of the housing and the platform in contact with the bearing surface. The system frictionally dampens vibrations received by the housing and isolates the platform from vibrations.

Abstract: There is disclosed herein a device which can function either as a brake or as a clutch and which relies upon the application of fluid which, under sufficient pressure, becomes essentially solid thereby providing substantial friction between a moving disk and a stationery housing. The device includes a stationery housing having therein a rotating disk within a chamber in the housing. A fluid is applied to the chamber, and when the pressure on the fluid is sufficiently increased it becomes substantially a solid thereby essentially locking together the disk and the housing to provide a braking or clutching action.

Abstract: Vibration damping device for vehicles includes: a rigid housing member having an accommodation space and fixed to a vibrative member; and an independent mass member having a rigid mass body and an elastic body layer bonded on the outer surface of the rigid mass body. The independent mass member is non-adhesively disposed in the accommodation space such that an outer surface of the independent mass member is opposed to the inner surface of the housing member with a predetermined gap distance therebetween, to thereby permit displacement of the independent mass member relative to the housing member. The independent mass member and the housing member is brought into elastic impact against each other, upon application of a vibrational load, at respective abutting surfaces thereof which are opposed to each other in a vibrational input direction.

Abstract: A friction vibration damper for damping the vibrations of a vibrating component comprising a body, a chamber and a plurality of elements, the body defines the chamber which is partially filled with the plurality of elements, the friction vibration damper, in use, disposed on or in the vibrating component characterized in that the friction vibration damper is configured to substantially prevent the elements operationally moving in a convection-like flow pattern.

Abstract: A system for the mitigation of cable stay vibrations, typically induced by wind and rain, utilizes a plurality of active damper bands positioned along the cable stay. Each damper band includes a shiftable mass and an energizing device for facilitating assisted shifting of the mass. A control assembly can actuate all or selected ones of the energizing devices in response to sensed magnitudes of cable stay vibration.

Abstract: A braking device including a chamber rotatably mounted on an axle, the chamber defining an inner cavity, a disc mounted on the axle in the inner cavity, the disc having opposing surfaces extending away from the axle, and a pourable material disposed in the inner cavity such that rotation of the chamber imparts a centrifugal force to the material, causing the material to be wedged between an inner surface of the inner cavity and the opposing faces so as to apply a braking force to the disc.

Abstract: A hydraulic shock absorber (10) is composed of a piston (3) that partitions the inside of a cylinder (1) into an extension side chamber (R1) and a compression side chamber (R2), a throttler (3c) for connecting the extension side chamber (R1) and the compression side chamber (R2), a piston rod (2) that extends from the cylinder (1) interlocking with the piston (3), an accumulator (11) that allows entrance and exit of a volume of hydraulic operating fluid equivalent to the volume of a portion of the piston rod (2) entered within the cylinder (1), and a spring (8) that pushes the piston (3) against the piston rod (2).

Abstract: The device dampens vibrations between objects, especially for preventing the transfer of vibrations from a primary object subjected to vibrations, to a vibration-sensitive secondary object. The secondary object is non-rigidly supported by a damping body, which has the same or essentially the same size of mass as the secondary object, and which in turn is non-rigidly supported on the primary object.

Abstract: A modular brake rotor includes a core having a central wall and a plurality of support ribs extending radially outwards therefrom. A pair of friction rings are secured to the support ribs. A viscoelastic vibration reducing element is disposed between the support ribs and the friction rings for creating a vibration reducing interface therebetween. The viscoelastic vibration reducing element is preferably a viscoelastic adhesive. In an alternate embodiment, the viscoelastic vibration reducing element is viscoelastic laminate including one or more layers of viscoelastic adhesive bonded to one or more intermediate materials.

Abstract: The invention relates to the use of low-density granular fill with a specific gravity less than 1.5, placed in hollow cavities built into turbomachinery blades, vanes, and shafts. The granular fill provides effective damping at lower frequencies than conventional passive damping treatment due to its low bulk compressional sound speed. Selected materials used for the granular fill treatment are chosen for specific turbomachinery needs, including temperature of operation. Rotation speed is also a factor because it induces on the granular material an apparent hydrostatic pressure associated with the centripetal acceleration, and sound speed in granular materials is a function of pressure raised to the power 1/n. Preferred designs for placement of low-density granular material in appendages and shafts are found using an iterative design tool based on the Direct Global Stiffness Matrix method.

Abstract: An operative hinge for use with an opening/closing body is provided which comprises a hinge case to be installed to a toilet bowl body for operating the opening/closing body; a shaft provided rotatably within the hinge case to support the opening/closing body; a stationary cam fixed within the hinge case and having formed therein a central through-hole through which the rotating shaft is axially penetrated; a cam provided within the hinge case and having formed therein a central through-hole through which the rotating shaft is axially penetrated to be slidable on, and rotatable with, the rotating shaft; and a resilient means for urging the rotatable sliding cam toward the stationary can, the hinge further comprising, to further positively control the rotation or the rotating means, a damping means consisting of a rubber ring fitted on the rotating shaft and interposed between the outer surface of the rotating shaft and the inner wall of the hinge case; and a viscous oil applied between the outer surface of th

Abstract: A hydraulic displacement machine that can operate as a pump or a motor in connection with an electrorheologic or magnetorheologic fluid includes a housing, a rotary piston arranged to rotate within a chamber in the housing, at least one displacement vane provided on the rotary piston, a plurality of field generating elements such as capacitor plate segments and/or coil arrangements that are each individually electrically energizable and that are arranged on the two sidewalls of the housing chamber distributed around the circumferential direction, and an actuator connected to each field generating element so as to move the elements of each pair selectively closer together and farther apart from each other. By applying an appropriate electric or magnetic field to the electrorheologic or magnetorheologic fluid between the field generating elements, the fluid is locally solidified in the "flow mode" to form a stationary seal plug within each fluid chamber between respective consecutive vanes.

Abstract: Apparatus and methods for isolating and absorbing energy associated with shock forces that are exerted upon an object, such as the energy attendant to shock forces experienced during and immediately following a mild to severe impact. The apparatus generally having: (a) a housing defining an enclosure; (b) at least one segment of non-liquid material contained within the enclosure; and (c) a piston placed within the enclosure. When the shock or impact force is applied to either the piston or housing, the piston urges the non-liquid material to pass or extrude through an aperture, orifice, channel or slot located either within the piston or the housing. The non-liquid material passes or extrudes through the aperture, orifice, channel or slot in a direction that is generally transverse to the relative movement of the piston within the enclosure.

Abstract: An antibacklashing fishing reel. A spool holds and releases a length of fishing line. An overrun condition of the fishing line being released from the spool is determined by a line motion sensor. The line motion sensor includes a rotatable member rotatable in response to movement of the fishing line during a cast and a sensor for sensing the rotation of the rotatable member. The sensor generates the line motion signal depending on the sensed rotation of the rotatable member. An electronically variable brake is controlled depending on the line motion signal for applying a variable braking force to resist rotation of the spool in response to the determined overrun condition of the fishing line being released from the spool. When the line motion signal indicates that the line is being played out from the spool slower than the spool is releasing it, an overrun condition is determined and the spool is braked to prevent the occurrence of a backlash.

Abstract: An operating hinge for a seat and seat lid of a toilet bowl, simply constructed and capable of controlling the angular moment of the seat and lid to softly stop them in place at their respective predetermined ends of pivoting stroke, provided.

Abstract: Apparatus and methods for isolating and absorbing energy associated with shock forces that are exerted upon an object, such as the energy attendant to shock forces experienced during and immediately following a mild to severe impact. The apparatus generally having: (a) a housing defining an enclosure; (b) at least one segment of non-liquid material contained within the enclosure; and (c) a piston placed within the enclosure. When the shock or impact force is applied to either the piston or housing, the piston urges the non-liquid material to pass or extrude through an aperture, orifice, channel or slot located either within the piston or the housing. The non-liquid material passes or extrudes through the aperture, orifice, channel or slot in a direction that is generally transverse to the relative movement of the piston within the enclosure.

Abstract: A damper variably moderates movement of a piston on a rod in a cylinder filled with highly pressurized elastomeric gum. An axial bore through the piston allows relative ease of movement when a relatively low force is applied to a rod driving the cylinder. A high stress or acceleration on the rod forces a steel washer carried on the cylinder to deform and block the bore. The stiffness of the washer is proportioned to the ability of the clearance of the piston in the cylinder and the pressure and stiffness of the gum to establish a threshold. Damping is provided according to a preselected function, namely low initial resistance, and sharp increase is resistance to movement of the piston in response to stress exceeding the threshold. This function is suitable for damping in such applications as earthquake protection for structures and high stress protection for railroad beds.

Abstract: The following relates to the use of low-density granular fill with a specific gravity less than 1.5, placed in hollow cavities built into turbomachinery blades, vanes, and shafts. The granular fill provides effective damping at lower frequencies than conventional passive damping treatment due to its low bulk compressional sound speed. Selected materials used for the granular fill treatment are chosen for specific turbomachinery needs, including temperature of operation. Rotation speed is also a factor because it induces on the granular material an apparent hydrostatic pressure associated with the centripetal acceleration, and sound speed in granular materials is a function of pressure raised to the power 1/n. Preferred designs for placement of low-density granular material in appendages and shafts are found using an iterative design tool based on the Direct Global Stiffness Matrix method.

Abstract: A vibration damping structure for a machine tool is provided. The structure includes first and second plate members disposed in an opposing spaced apart relationship with one another. A cast structure formed of a polymer concrete extends between the first and second plate members. A first structure is attached to the first plate member and extends inwardly of the cast structure. The first structure has a compression surface extending in a spaced apart relationship from the surface of the first plate member. A second structure is attached to the second plate member and extends inwardly of the cast structure.

Abstract: An antibacklashing fishing reel having an electronically variable brake for preventing backlash. A spool holds and releases a length of fishing line. An electronically variable brake is coupled with the spool for applying a variable braking force to resist rotation of the spool during casting to prevent the spool from overrunning the length of fishing line being released from the spool. An overrun status of the length of fishing line being released from the spool is determined, and a status signal dependent thereon is generated. A controller receives the status signal and controls the electronically variable brake to apply the variable braking force to resist rotation of the spool during casting so that a progressively greater braking force is applied when the overrun status indicates that the spool is overrunning the length of fishing line being released.

Abstract: Vibration damping devices for skis and other applications, the damping devices comprising a Cantilevered Impact/Friction Damper (CIFD) and an Improved Constrained Layer Damper (ICLD), the CIFD including a frame affixed to a portion of the vibrating body and having a cantilevered tubular member adapted for oscillation relative to the frame such that when subject to high amplitude vibration, a free end of the tubular member having a mass alternately strikes a pair of confronting stops, the tubular member having a plurality of particles disposed therein which dissipate low amplitude vibration through inter-particle friction; the ICLD comprising a spacer member having at least one layer of viscoelastic material and at least one constraining layer attached thereto, the spacer member having a plurality of slots spaced along the longitudinal extent thereof to reduce the bending stiffness of the spacer member without diminishing the damping effect.

Abstract: A vibration damper device (1) intended to be mounted on a sports article such as, in particular, a tennis or squash racket, a gliding board or a golf club, whereinthe device includes at least two elements (3, 4) superposed to form a stack and mounted so as to slide relative to one another, each element (3, 4) in said stack being secured to the article by one end, the ends (13, 14) of the adjacent elements being offset relative to one another so that the deformations of the article (8) due to the vibrations cause the adjacent elements (3, 4) to slideand at least one of the superposed elements (4) is magnetized, one of the other elements (3) in the stack being made of a material which is sensitive to the magnetic field generated by the magnetized element (4).

Abstract: A cushioned tow bar for connecting a drive trolley to a load carriage in a power and free conveyor system includes a particulate shock absorber with a damping chamber which is partially filled with particulate material, such as small ball bearings, which act to dampen the movement of a piston through the damping chamber. The damping chamber comprises a portion of a sleeve which includes a threaded end cap which mates with threads on an open end of the sleeve. The threads in the sleeve extend along the longitudinal axis of the sleeve to an extent which allows the end cap to be threadably adjusted, changing the portion of the sleeve forming the damping chamber, and thus adjusting the cushioning effect of the tow bar.

Abstract: A fluid free damper, comprising a spindle member; housing means mounted for relative eccentric rotation with respect to the spindle member; and engagement means interposed between the spindle member and the housing means for rotation along with one of the housing means and the spindle member with respect to the other one of the housing means and the spindle member so as to be deformably compressed between the spindle member and the housing means and thereby generate a resistive damping force between the housing means and the spindle member in response to the eccentric rotation of the one of the housing means and spindle member with respect to the other one of the housing means and the spindle member.

Abstract: An elastomeric shock absorber having enhanced damping characteristics comprises a casing filled with a compressible elastomer; a piston rod immersed in the elastomer; a piston head mounted on the piston rod and the piston head is provided with connecting ports communicating with the front and back spaces of the piston and is also equipped with a mobile member. The mobile member is located between a surface from which the connecting ports emerge as well as a ring or like stop block. The stop block is mounted on a section of the piston head facing a flow chamber, wherein the piston head moves into and out of an outer cylindrical surface of the casing and wherein at least one groove is provided on an inner surface of the casing, which together with the outer cylindrical surface of the piston head form a flow chamber shaped as a solid of revolution, the solid of revolution being selected from the group comprising a cone, a ring, a torus and any combination thereof.

Abstract: A thixotropic material is charged in a container. The container also holds a movable member which is placed in the thixotropic material so as to stir the thixotropic material. A force transmitting element is connected to the movable member. When an object, the vibration of which is to be controlled, is out of resonance, the amplitude of vibration is so small that the thixotropic material is in a gel state, thus presenting a comparatively large spring constant for the vibration control apparatus. As the excitation frequency is increased towards the resonance range, the amplitude of vibration is increased correspondingly, so that the movable member stirs the thixotropic material to generate stress in the latter, whereby the phase of the thixotropic material is changed from gel to sol. Consequently, the natural frequency of the vibration system, including the object and the vibration control apparatus, is lowered, thus averting resonance.

Abstract: The electromagnetic valve includes a magnetic housing (11, 12, 13), an electromagnetic coil (15) received in the magnetic housing and a plurality of movable parts including a movable magnetic armature (23,36) and a movable valve stem device (58) for valve opening and closing. To provide a damping of the motion of the movable parts, at least one of the movable parts (23, 36, 58), advantageously a part of the armature, is provided with a hollow compartment (72) and a damping mass (74) at least partial filling the hollow compartment (72). The volume of the hollow compartment (72) is greater than the volume of the damping mass (74) so that motions of the magnetic armature and other parts are damped by the frictional and impact losses occurring in the damping mass (74).

Abstract: A dynamic absorber suspension strut includes a sealed hydraulic damper mounted in an outer tube. An absorber mass is supported on a spring inside the outer tube. The absorber mass divides an interior of the outer tube into first and second fluid chambers. A fluid conduit is provided between the chambers. A control valve controls fluid flow in the fluid conduit to provide a desired damping of wheel hop frequencies. The damper is tuned to provide a desired damping of body frequencies.