Abstract: A fluid mounting (20) for isolating or damping vibration between a vibrating member (21) and a structure (23). In one aspect, the fluid mounting (20) includes inner (22) and outer (24) members, a flexible element (26), first (28) and second (30) operating chambers, a fluid passageway (32) interconnecting operating chambers (28, 30), and a partitionless volume compensator (36) including a compensator chamber (38) separated into a gas-filled portion (40) and a fluid-filled portion (42). Notably, the chamber (38) is devoid of any separating barrier. At least one lock passage (44) interconnects the fluid-filled portion (42) with one of the first and second operating chambers (28, 30), and a working fluid (34). Preferably a bubble trap depression (46) focuses any gas bubbles into the lock passage (44). In another aspect, mounting (20) may include laminated shim construction with sloping profiles thereon to prevent bubble trapping.

Abstract: A mounting (20) which provides superior isolation yet which eliminates damaging edge-induced shear strain (ENT) buildup in the elastomer sections (28) and (30) when exposed to high temperatures by having a first elastomer section (28) loaded in compression and a second elastomer section (30) loaded in shear. Exposing the mounting (20) to elevated temperature environments allows the first elastomer section (28) to expand in height and places the second elastomer section (30) in shear to accommodate the height change. The instant invention compensates for fluid and elastomer expansion due to high temperatures by providing a mechanical type compensator (37) which takes up less space and eliminates the pressure loss associated with air-charged compensators (99). Further, a unique combination of fluorinated fluids and polysiloxane polymer enables the mounting (20) to withstand temperatures of greater than 200 deg F. for extended periods of time.

Abstract: An Active Vibration Absorber assembly (20) including a casing (24), a first tuning mass (32) supported relative to the casing (24) which is actively vibratable by a force generator (40) in a first direction (along an A--A axis), a second tuning mass (32') supported relative to said casing (24) which is actively vibratable by a force generator (40') in a second direction (along axis B--B) generally orthogonal to the first direction, and a flexible member (26) flexibly supporting the casing (24). In a first embodiment, the tuning masses (32, 32') are vibratable by a magnet and coil assembly within shakers (25, 25') and the flexible member (26) is a beam. In other embodiments, multiple beams are employed to restrict the vibration of casing (24) to substantially planar motion. The AVA assembly (20) finds application in Active Structural Control (ASC) systems for actively canceling vibration or noise in vehicle cabins (example: automobiles, aircraft).

Abstract: An Active Structural Control (ASC) system (10) and method which includes a plurality of Active Vibration Absorbers (AVAs) (40) attached to a yoke (32) included within a pylon structure (28) preferably comprising a spar (38) and a yoke (32) which is located intermediate between an aircraft fuselage (20) and an aircraft engine (18) for controlling acoustic noise and/or vibration generated within the aircraft's cabin (44) due to unbalances in the aircraft engine (18). The ASC system (10) includes a plurality of error sensors (42) for providing error signals, and at least one reference sensor (49 or 50) for providing reference signals indicative of the N1 and/or N2 engine rotations and/or vibrations, and a preferably digital electronic controller (46) for processing the error and reference signal information to provide output signals to drive the plurality of AVAs (40) attached to the yoke (32).

Abstract: A controllable platform suspension system (20) for treadmills (18) and other platforms and devices therefor which exhibit controllability of the impact condition of the platform, such as a treadmill deck (36). In the treadmill application, user-selectable damping/stiffness is provided to simulate variable track conditions, such as pavement, rubber, grass, gravel, sand, and the like. The controllable suspension system (20) comprises spring mounts (40) or the like or a flexible deck (36) for allowing movement of the deck (36) relative to the frame (22) at a contact location (29) due to impact and a controllable device such as an Electrorheological (ER) device, Electrophoretic (EP) device, Electromechanical Hydraulic (Semi-Active) device, controllable mounting, or a Magnetorheological (MR) device, such as an MR brake (42a, 42a, 42b), MR damper (42d), or MR mount (42c, 42e, 42f) interconnecting between the frame (22) and platform (36) to provide the user-variable impact restraint.

Abstract: A tuned vibration absorber includes a mounting plate having at least two, and alternatively four, mounting holes in spaced relationship from a longitudinal center axis of the plate. An elastomeric spring is bonded to the mounting plate. A main tuning mass is bonded to the elastomeric spring opposite the mounting plate, and fine tuning masses are riveted directly onto the main tuning mass. The elastomeric spring and main mass both have a rectangular profile to maintain a low profile height from the mounting plate. A cover is formed of a single sheet of metal bent to form a rectangular box with one open side. The cover includes mounting flanges with holes that align with the mounting holes on the mounting plate. For mounting the vibration absorber on a stiffening ring of an aircraft frame, a spacing plate is positionable between a portion of the mounting plate and the stiffening rib of an aircraft frame, and adjacent to an overlapping secondary stiffening ring to provide a flat mounting surface.

Abstract: A method for automatically calibrating a controller (44) for a controllable damping system (40), for example, the suspension and damping system for a truck seat or cab, includes the steps of receiving a initiation signal that is checked against criteria to ensure that calibration is actually intended. The seat (20) or other body (ex. a vehicle cab) is then moved to a first limit position, where a sensor (50, 50') reads a position signal, and to a second limit position, where another position signal is read. Preferably, a midpoint, or neutral position is calculated from the measured position signals, and the seat (20) or other body is moved to this neutral position. A range of movement is determined from the first and second position signals. Preferably, end stop limits are calculated as predetermined fractions of the range of movement value. All values are stored for use by the controllable damper system (40).

Abstract: A vibration control apparatus (20) and method for a calender (18) for controlling vibration between two or more rolls (ex. 22, 24) which controls vibration induced thickness variations in a medium (27) exiting from the nip. The apparatus (20) includes a frame (19), a first and second rolls (22, 24) mounted relative to the frame (19), and a force generator (32), such as an electromechanical active actuator, servo-hydraulic actuator, controllable semi-active damper, Active Vibration Absorber (AVA), or Adaptive Tuned Vibration Absorber (ATVA), provides cancelling forces to control vibration between the first and second roll (22, 24) thereby, controlling such vibration induced thickness variations in the medium (27). Preferably, the apparatus (20) includes at least one sensor (ex.

Abstract: A prosthetic suspension unit for cushioning shocks in a prosthetic is provided. The unit includes a cylindrical sleeve attachable to a first prosthetic member; attachment member attachable to a second prosthetic member; a slide bearing allowing the attachment member to slide axially relative to the sleeve; an energy storage member cooperating between said attachment means and the sleeve; a piston positioned to slide within said sleeve and engage an axial end of the energy storage member; and anti-rotation mechanism cooperative between said sleeve and the attachment member for preventing relative rotation therebetween.

Abstract: An active fluid mounting for isolating vibration between a vibrating member (21) and a structure (23). In one aspect, the active fluid mounting (20) includes an inner member (22), an outer member (24), a first flexible element (26), and an cartridge-like active fluid element (28) which is unitary and readily detachable, attached between the inner and outer members, (22) and (24).

Abstract: A flex-plate tuned vibration absorber (35) including a tuned mass (43) flexibly suspended by one or more flex plates (58). In one aspect the tunable vibration absorber (TVA) (35) is adaptive in that the position of the mass is adaptively moveable with respect to its initial position, thereby effectuating a change in the TVA's resonant frequency. In one embodiment, the tuned mass (43) moves along a rigid frame (53). In another, movement of the mass (43) statically stresses a preferably disc-shaped flexible plate (58) thereby changing its stiffness. Preferably, a reducer (78) gears down the speed of the motor (64). In another aspect, a TVA system includes a base sensor (40) providing a base vibration signal, a mass sensor (38) for providing a vibration signal of the tuned mass (43), and an electronic controller (42) for generating a control signal to the TVA (35). The TVA finds application for absorbing vibration in vibrating structures, such as in aircraft.

Abstract: A magnetorheological fluid device which exhibits excursion (stroke or rotation) dependent resistance (force or torque) which is obtained passively. Linear and rotary embodiments are described. The devices described herein include various ways for passively varying magnetic circuit reluctance to accomplish the stroke or rotation dependent characteristic.

Abstract: A fluid-filled Active Vibration Absorber (AVA) (20) is described for attaching to, and controlling dynamic vibration of the member (22). The AVA (20) is comprised of primary tuning mass (23) preferably including an additional inertial tuning mass (26) which is associated with a primary resonant frequency (fn1), a flexible element (28) for interconnecting the primary mass (23) and, thus, interconnecting inertial tuning mass (26) to member (22), at least one, and preferably two, fluid chambers, (30) and (32), each having a defined volume stiffness Kv'1, Kv'2, a fluid (34) contained within the at least one and preferably two, fluid chambers, (30) and (32), a moveable piston (36) dynamically interacting with the fluid (34) in the at least one fluid chamber and preferably, in first and second fluid chambers, (30) and (32), to cause pressure variations which dynamically drive the primary tuning mass (23) within a range about the primary resonant frequency (fn1).

Abstract: A mount for isolating a vibrating member from its support. An elastomeric element is made up of four components that are preferably bonded to the inclined outer surface of an inner member and the inclined inner surface of an outer member. One of the inner and outer members is bifurcated and drawing the two halves into mating engagement results in the elastomeric components being preloaded simultaneously in compression and shear. The elastomeric element is preferably formed with portions which snub movement in each of three orthogonal directions. The dimensions of the pair of elastomeric components above or below the vibrating member may be different than the other pair since the greater compression strain on one pair of components will make its stiffness characteristics more critical to determining the effective stiffness of the mount.

Abstract: An isolator for use in a hand-held vibrating device for providing optimum vibration isolation by utilizing elastomeric sections. Six embodiments are shown which utilize elastomer sections to enhance vibration isolation along an axial direction of vibration. A first embodiment includes a frustoconical section, while the second employs a W-shaped buckling element. A third embodiment includes use of a tuned fluid inertia which is tuned to substantially coincide with a predominant operating frequency of the vibrating device and produces forces to substantially reduce the vibration transmission, while three other embodiments employ metallic buckling springs. Another embodiment employs a tuned vibration absorber and still another combines a tuned mass with a buckling column.

Abstract: An elastomer bearing (20) and assembly method therefor. The bearing (20) includes an inner member (22) having an outer profiled surface with a maximum radial dimension, an outer member (24) having a minimum radial dimension which is smaller than said maximum radial dimension and a inner profiled surface. The outer member (24) includes first (26) and second halves (28) being inserted axially over the spherical portion (23) of inner member (22). Each halve (26, 28) including axial threaded portions (32) which are threadedly interconnected to secure halves (26, 28) together. An elastomer layer (30) is bonded to said outer profiled surface of said inner member (22) and said inner profiled surface of said outer member (24). In another aspect, the profiled surfaces are spherical surfaces. Preferably, air is vented into the threaded escapeway (33) during the bonding process. A radial gap (34) is provided to aid is air removal/venting.

Abstract: A flexibly-mounted active vibration absorber (AVA) which has a secondary controllable mass M.sub.3. If the passive resonance of mass M.sub.2 of the tuned absorber is insufficient to control the input vibration, a secondary mass M.sub.3 is vibrated at a frequency, amplitude and phase sufficient to make up the deficiency in mass M.sub.2. Many embodiments are described which depict variations on the first spring used for flexibly mounting the AVA, the actuators used to drive the AVA, and the attachment features for attaching to a vibrating member. Further in another aspect, means for counterbalancing the moments produced by the AVA are described.

Abstract: A spherical bearing used in a rod end housing is modified with an elastomeric member equally precompressed in an amount of about 30% of an unstressed thickness of the elastomeric member to isolate the transmission of vibrations and sound. Such spherical elastomeric bearings can be used in any application where a conventional spherical bearing is used such as cable connections, clutch linkages, etc., in trucks, farm tractors, and various other pieces of equipment.

Abstract: A controllable vibration apparatus having an electrical connection to a controllable valve made through a single-strand electrical conductor. In one embodiment, the piston and rod are preferably used as the source of ground or return electrical path. An axially compressed sealing element provides radial sealing against the conductor. An accumulator including a flexible diaphragm provides separation of fluid and accumulator chambers. In magnetorheological (MR) fluid dampers, a special sealing system including a relationship between piston rod surface finish and particle size is provided. A surface treated metal bushing is used with a lip seal to prevent escape of fluid and support side loads. The controllable valve can be formed from top and bottom pole pieces spaced from an outer ring to define a passageway. The pole and ring are preferably secured together by non-magnetic bridging elements. Preferably, the coil assembly is configured with integral axially-extending pins for ease of connection.

Abstract: An insert used to connect aircraft floor panels, and the like, to supporting structure includes features which function to isolate the supported panel from vibrations in the supporting structure. The isolation of the panels leads to reductions in SIL (Speech Interference Level) noise within aircraft cabins. The insert consists of internal and external rigid components separated by a contoured elastomeric component. The elastomeric component is preloaded when installed via a fastener extending through the inner rigid component and attaching to the supporting structure. The outer and inner rigid components are sized such that the inner rigid component will not pass through the outer rigid component, thus providing a safetied installation of the panel. The elastomeric component extends below the bottom of the outer rigid component and provides soft snubbing against the supporting structure during loading of the panels. This allows some level of isolation while restricting motion of the panels.