A leaf spring structure is designed as a single piece to be able to change the spring rates of leaf springs under a load independently from the manufacturing material. The operating mechanism of the leaf spring allows for increasing the spring rates by deactivating the short spring, which remains between the point A and the point B, as a result of the interaction between the short spring and the long spring after a certain amount of vertical displacement in the leaf spring.

The invention relates to a tuned mass damper or vibration damper which, with the aid of an assembly (2) of a plurality of stacked, specially shaped or bent leaf springs (2.1), can be adapted over a certain range to the disturbance frequencies acting on a component to be damped or of the vibration system to be damped, the position of the damper mass (1, 34) being changed essentially only slightly. The invention relates in particular to one- and two-dimensionally effective tuned mass dampers. The tuned mass dampers according to the invention are suitable in particular for installations, vehicles and machines that undergo frequent changes in rotational speed, resulting frequently in disturbance frequencies that become noticeable, in particular, in the form of structure-borne sound, or other vibrations.

A spring element that includes one or more loop portions. Each loop portion provides vibration isolation characteristics for the spring element. One or more fastening portions of the spring element enable the fastening or connecting of the spring element to one or more structures. A ratio of a longitudinal measure of each loop portion to a transverse measure of the spring element is between 7.5 and 500. A pair of loop portions may be integrally joined together at a middle section to form a continuous loop. A pair of fastening portions may be integrally joined to opposing sides of the middle section, respectively. One of the fastening portions may be connected to a first structure and the other one of the fastening portions may be connected to a second structure.

A variable stiffness leaf spring mechanism and method of locking parallel leaf springs allow for a wide range of stiffness settings in a low-mass package. By varying the number of parallel leaf springs as well as the thickness and stiffness of each layer the system stiffness and range of stiffness settings can be optimally tuned to each application. Additionally, by locking leaf springs without inducing large normal forces from a clamping mechanism, the frictional wear on the system is greatly diminished. In addition to increasing the life cycles of the system, this will decrease auditory noise emitted during operation. The system and method can be applied to lower extremity prostheses to allow for more biological emulation than passive prostheses in a lower mass package than powered prostheses.

The invention provides a vibration isolation system (IS), comprising a piston (402) to carry a payload, a connecting member (410), a spring (404) and a flexible member (408). The spring is arranged to support the piston along a direction with a positive stiffness. The flexible member is arranged to apply a force to the piston along the direction via the connecting member with a negative stiffness.

A variable stiffness spring assembly includes first and second members made of a first material and separated by a gap along at least a portion of their lengths, and one or more layers made of a second material disposed in the gap. The variable stiffness spring assembly can be incorporated into or take the form of a limb support assembly, such as a prosthetic foot. The second material disposed between the first and second members is rate-sensitive or speed-dependent, such that the material exhibits different properties when the user of the prosthetic foot is walking at high or fast walking speeds compared to low or slow walking speeds. The prosthetic foot can exhibit high damping and energy absorption, and therefore stability, at slow speeds, and high energy return at faster speeds.

To reduce vibration of movable airfoil structures, such as rudders, elevators, and ailerons, a spring device, a leaf spring for example, is mounted to an airfoil mounting structure, such as a vertical tail plane, horizontal tail plane or the wings, such that the spring device exerts a force on a cam device, which transforms the spring force into an airfoil torque. The airfoil torque is applied to the airfoil structure and thus reduces a risk of vibration. The cam device is configured to redirect the spring force such that when the airfoil structure is moved in a first direction, torque decreases and when moved in the opposite second direction the torque is zero.

Described is a fibre composite component designed as a spring, comprising at least one spring section and at least one force transfer structure (2). In the end portion forming or surrounding the force transfer element (3) the fibre composite material of the fibre composite component (1) is divided, in a plane perpendicular to the longitudinal direction of the force transfer structure (2), into at least two fibre composite material strands (4, 4.1, 4.2). Two adjacent fibre composite strands (4, 4.1, 4.2) run in opposite directions, overlapping over a specific angular portion and each forming an eye, with their mutually opposed side faces (7) force-transmittingly connected in the overlapping portion.

A vibration isolation system includes multiple isolators between an inner object and an outer housing that surrounds the object. In one example the inner object may be a rack or container that holds electronics, such as printed circuit boards, and the outer housing may be a housing for a missile, such as a supersonic or hypersonic missile. The isolators have flexures to attenuate vibrations, isolating the inner object at least in part from vibrations encountered by the outer housing. The flexures may be oriented in different directions for different isolators to change the resonant frequency of the system for a given axis. In addition the isolators are able to compensate for differences in expansion between the inner object and the outer housing. The isolators may also include multi-part isolators that have spring-loaded wedge elements used to expand the isolators in one or more radial directions.

Rotor hubs described herein include a frustoconical body having a base, a frustum, and a longitudinal axis extending therebetween, and a plurality of elongated protrusions spaced about a circumference of the base and extending from the base parallel to the longitudinal axis.