Abstract: Elastomer dampers (20) and (120) for damping movement between two relatively moveable members, such as shimmy motion between components in an aircraft landing gear assembly (10). Each damper includes a housing (24) having an internal cavity (36) with a cylindrical interior surface (34) and an opening (41), and a member assembly (28, 128) moveable relative to the housing (24) having an elongated shaft (30) received through the opening (41) with a piston head assembly (32) mounted thereon. The piston head assembly (32, 132) has a annular support element (46, 146) received over the shaft (30) with a sleeve-like elastomer member (48, 148) received over it. The elastomer member (48, 148) engages the interior surface (34) in an interference fit relationship thereby radially precompressing the elastomer element (48, 148) in the range of between about 5% and 15%.

Abstract: A railway car side bearing includes a lower housing member, an upper housing member spaced apart from the lower housing member, and an elastomeric spring member interposed between the upper and lower housing members that buckles upon application of vertical loading to provide a spring rate that softens within a range of compressive loads. The upper and lower housing members cooperate with each other to allow for relative vertical movement therebetween, but restrain lateral and rotational movement therebetween. The elastomeric spring member has a first set of spring rates when subjected to axial loads within a first range. However, when the side bearing is subjected to axial loads within an second range, the elastomeric spring member buckles and exhibits a second set of substantially softer spring rates.

Abstract: An elastomeric mounting configured to be inserted in a pocket in a vibrating first member and to isolate the first member from a second member on which the first member is mounted. The mounting includes a rigid tube, a substantially rigid radial disk at one end of the mounting, and an elastomeric member including a tubeform section essentially surrounding the rigid tube and a sandwich section bonded to an axially projecting surface of the rigid radial disk and extending radially outward from the tubeform section.

Abstract: A tuned vibration absorber and vibration-reduced pipeline system utilizing same. The tuned vibration absorber includes a support frame, a tuning mass mounted for pivotal movement relative to the support frame about a pivot; the tuning mass including a lever, and a spring contacting the lever. In the vibration-reduced pipeline system, the absorber's support frame is preferably secured atop of the pipeline section, preferably by at least one strap, to absorb vibrations thereof. In a preferred aspect, the tuning mass includes an arm extending from the pivot in a first direction and a weight repositionably mounted thereon. The lever extends from the arm along a second direction substantially orthogonal to the first direction. Preferably the line of action (along A--A) of the spring extends substantially parallel to the first direction. An adjuster is provided for readjusting a position of the tuning mass relative to said support frame due to drift in the spring.

Abstract: A device for hand and wrist rehabilitation includes a small, hand-held housing for a magnetic fluid controllable resistance brake. Tool elements that provide a grip for a patient releasably snap onto to a shaft of the brake, and allow the patient to exercise the wrist or hand in a variety of positions. The controllable brake provides fine control of the resistance, which is selected by the user with a knob.

Abstract: An isolator (26) and assembly method therefor. The isolator (26) is particularly useful for aircraft thrust reverser doors, and the like, and includes an outer member (28), and a isolator component (29). The outer member (28) has a central axis (A--A), a generally non-planar inner peripheral surface (32), and first and second axially extending slotted entryways (48, 48'). The isolator component (29) preferably includes a component axis (B--B), an inner member (30) having an external radial peripheral surface (33), and an elastomer or metal mesh member (40) surrounding said external radial peripheral surface (33). The isolator component (29) is assembled and retained within said outer member (28) by insertion endwise through said first and second slotted entryways (48, 48'), and rotating 90.degree. such that the component axis (B--B) is substantially aligned with the central axis (A--A).

Abstract: A method of controlling a controllable force generator within a controllable suspension system interconnected between a first member M.sub.1 and a second member M.sub.2. The method includes the steps of obtaining a first signal (V.sub.abs) representative of the absolute velocity of the first member M.sub.1, obtaining a second signal (V.sub.rel) representative of the relative velocity between the first and second members, and setting a desired damping force for the generator based upon a control policy which defines a control surface. The control policy includes a preselected gain, an absolute velocity, and a shaping function of relative velocity wherein said control surface exhibits only continuous first derivatives for V.sub.rel *V.sub.abs >0 and wherein the control surface is devoid of any surface discontinuities. This control policy effectively eliminates the jerkiness in certain prior art control methods, such as skyhook.

Abstract: A bonded component (126) adapted for insertion in a housing (120) thus forming a mount (118). The bonded component (126) includes an inner member (128) including a outer periphery (129) having a preferably non-planar profile along its width and an elastomer (130) bonded thereto. The elastomer (130) includes a first arcuate section (142) extending through a first arc (.theta..sub.1) and having first and second lateral faces (150a-c), a second arcuate section (142') extending through a second arc (.theta..sub.2) also having first and second lateral faces (150b-d), notches (148a-d) formed in first and second lateral faces of each of said first and second arcuate sections, the notches only extending part way across each of said sections. In another aspect, the location of the notches (148a-d) are vertically and/or angularly offset from said fore-and-aft axis (146).

Abstract: A device for cushioning shocks is provided. A relatively unstable, collapsible elastomeric member which has guides integrally formed thereon, is surrounded by a guide sleeve which provides controlled deflection as well as damping for the elastomeric member. A piston is used to collapse the elastomeric member. The cush of the present invention can be utilized in hydraulic systems where an elastomeric bladder provides primary energy storage and in other applications where the cush of the present invention is the primary damper. This cush can be preloaded and, where desired, can be provided with the capability to adjust the preload.

Abstract: A fluid damper to damp unwanted vibration between a first member (21) and a second member (23, 23'), such as between a rotor blade and hub within a helicopter rotor system. According to a first aspect, the fluid damper (20) includes an outer member (22), first and second inner members (24, 24'), first and second elastomeric elements (26, 26'), a hollow (28), a divider (30) subdividing hollow (28) into first (32) and second (32') operating chambers, a connector (34) interconnecting first (24) and second (24') inner members, a fluid passageway (36) interconnecting operating chambers (32, 32'), a fluid (38) contained within said passageway (36) and operating chambers (32, 32'), and a volume compensator (40) including a compensator chamber (42) housed within one of first (24) and second (24') inner members. In another aspect, an annular bubble trap (58) is formed in a wall portion (62) of the operating chamber (32) to focus any air bubbles into a fill port (54) during fill.

Abstract: An elastomer detent assembly includes a first member and a second member. The first member includes a plurality of recesses formed in a surface thereof. The second member is engagable with the plurality of recesses and includes at least one detent finger. A dimension of the at least one detent finger is sized relative to a comparable dimension of the surface such that, upon application of a force, the at least one detent finger will move in finite increments relative to the first member providing a detent mechanism. At least one of the first and second members further includes an elastomer portion and a radially extending flange for limiting axial motion between the members. Embodiments including elastomer bonded to either an inner or an outer member are provided.

Abstract: A method for controlling end stop collisions in electro-mechanical systems including dampers or actuators. In a first aspect, a velocity-squared control method determines an end stop control signal (V.sub.end stop) based, at least in part, upon a square of the relative velocity (V.sub.inst). Preferably, the displacement (.delta..sub.end) to the end stop is also used to derive the end stop control signal (V.sub.end stop). In another aspect, a snubber control method is employed which produces a snubber control signal (V.sub.snub) based, at least in part, upon a continuous function of a snubber incursion distance (.delta..sub.z) within a snubber zone (Z). Preferably, the velocity-squared end stop and the snubber control methods operate together. When used in conjunction with an end stop control method, the snubber control method prevents end stop collisions for cases where the end stop control algorithm alone would not.

Abstract: A fluid and elastomer damper includes a first and second members and an elastomer section flexibly mounting the second member to the first member and allowing lateral movement therebetween. The elastomer section includes an inner wall forming a portion of a cavity defined within the damper and a damping fluid disposed within the cavity. A flexible damping plate separates the cavity into first and second chambers. At least one passageway is formed between the damping plate and the inner wall, the passageway exhibiting a gap dimension between the wall and the damping plate. When lateral movement occurs between the first and second members, the gap dimension is maintained substantially constant by flexing of the damping plate along the lateral direction.

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 method and apparatus is described for limiting transient motions between an aircraft power member and aircraft structure. The apparatus incorporates a coupler (20) for use with inertial-type mounts and includes a body portion (21) having a coupler piston (32) telescopically received therein. Upon exceeding a transient relative motion which causes a fluid flow velocity to be exceeded, seat (38) formed on coupler piston (32) interacts with lip (39) on body portion (21) to cause a fluid flow restriction. This method and apparatus restricts and limits transient motions, i.e., acts as a snuffer, to limit further relative motion between an aircraft power member (54) and an aircraft structural member (52). The coupler piston (32) preferably includes a flexible seal (38) formed thereon and orifice (40) therethrough for providing additional throttle-type damping upon snubbing.

Abstract: An elastomeric bumper restricts movement of large objects such as diesel engines to .+-.0.5" along the bumper's axis. The bumper includes a solid elastomeric button, an elastomeric sleeve spaced therefrom by a gap, and a rigid, tight fitting cup which surrounds the sleeve and limits the outward bulging of the elastomer. The button has an axial length which exceeds the length of the sleeve by an amount which defines a first volume of elastomer. That volume is designed to be equal to the volume of the gap. When the movement of the large object has caused the equivalent of the first volume of elastomer to flow into the gap, additional movement of the object is resisted by bulk loading of the elastomer which behaves as an incompressible fluid and resists additional motion with the full weight of the support to which the bumper is attached.

Abstract: A method is described for identifying the primary load path of a particular engine. An elastomeric mount may then be made laterally soft in a first (in the disclosed case, the tangential) direction and more rigid in the direction of the primary load path. Efforts can then be directed to dynamically softening the mount in the primary load path. Specific apparatus may include passive fluid devices, active fluid devices, passive non-fluid devices and active non-fluid devices. In the case of a fluid mount, another feature of the invention is to have an auxiliary fill port of the volume compensator in alignment with at least one and, preferably both, of the primary fill port for the mount and the inertia track to facilitate filling.

Abstract: Actuators for active vibrational energy control systems which are frequency focused. The high-frequency cancellation function is decoupled from the low-frequency cancellation function to enable the size, force, number and placement of the actuators to be optimized. A hybrid system employing structural actuators to cancel low-frequency vibrations and speakers to cancel higher-frequency vibrations is also taught.

Abstract: A system (20) which includes a frequency-dependent decoupler (21) arranged in a series-spring relationship with an actuator (26) for supplying active forces to cancel vibration. The system (20) also includes a spring (28) for providing a primary load path. The system (20) is responsive to at least one sensor (32, 34, 36 or 38) and is controlled via controller (30). The decoupler (26) has greater frequency dependency than the spring (28) and allows the actuator (26) to be effectively decoupled at low frequency, yet coupled at high frequency. This frequency dependent coupling allows the system (20)to accommodate transient static and low frequency loads and motions by allowing motion across the decoupler (21). However, at high frequency, the decoupler (21) becomes stiffer and couples the actuator (26) with the moving members (22) and (24) such that motion across the decoupler (26) is minimized and the actuator (26) becomes more effective at high frequency attenuation.

Abstract: A drive coupling is fail-safed by providing an inner metallic member with a pair of machined opposing flat surfaces that can engage a pair of pins that are positioned in pockets in the intermediate elastomeric member. These pins are anchored in place with respect to the outer housing by staking the ends of the pins, or the like.