A personal care appliance which includes at least one flexible spring. The flexible spring having an grounded section with an outer surface and an inner surface, a rotational member arranged radially within the grounded section, wherein the rotational member is arranged to rotate within the grounded section in a first rotational direction about an imaginary rotational axis, and a compliant member having a first end and a second end, wherein the first end is operatively engaged with the inner surface of the grounded section and the second end operatively engaged with the rotational member. The compliant member has a first stiffness such that the compliant member is arranged to resist rotation of the rotational member in at least the first rotational direction.

A flexible shock-absorbing parts, suitable for use in a flexible damping device which connects and absorbs torque from two different mechanical shafts, so that they are coaxial during transmission. The flexible shock-absorbing parts is arranged between the two machines and closely attached to them; the flexible shock-absorbing parts are arranged radially on the first plane. The first plane is composed of the X-axis and the Y-axis in the Cartesian coordinate system. When the flexible shock-absorbing parts are installed in the vehicle, it allows the vehicle to absorb larger instantaneous external forces received by the wheels when the vehicle is travelling so that the impact of these external forces on the structure of the motor and the second gear inside the gear box can be reduced, thereby achieving protection for them.

Proposed is an elastic body having variable rigidity, wherein the elastic body is used in a series elastic actuator module, connects an input and an output, and has a rigidity that varies according to the applied torque. The elastic body having variable rigidity comprises: a connection part which receives torque from the input side or the output side; and a spring part connected to and receiving torque from the one selected from among the input side and the output side which is different from the connection part, wherein the spring part is formed integrally with the connection part and has a rigidity that varies as the connection part and the spring part come into contact with each other due to deformation caused by the applied torque.

A joystick device including a hollow housing having an endless boundary structure and a ceiling structure with an opening; a control-stick having a head portion and a stem portion, the hollow housing surrounding the stem portion with the head portion outside the hollow housing; and a plurality of biasing curved arm members extending outwardly from the stem portion and movable with the control-stick as a whole relative to the hollow housing along a plane at least substantially perpendicular to the stem portion. Each of the plurality of biasing curved arm members having a curved segment with a convex side directed towards a respective corresponding portion of the endless boundary structure so as to bias the stem portion when the control-stick is being moved towards said portion. The plurality of biasing curved arm members being distributed around the stem portion so as to cooperate with each other to centre the control-stick.

Proposed is an elastic body having variable rigidity, wherein the elastic body is used in a series elastic actuator module, connects an input and an output, and has a rigidity that varies according to the applied torque. The elastic body having variable rigidity comprises: a connection part which receives torque from the input side or the output side; and a spring part connected to and receiving torque from the one selected from among the input side and the output side which is different from the connection part, wherein the spring part is formed integrally with the connection part and has a rigidity that varies as the connection part and the spring part come into contact with each other due to deformation caused by the applied torque.

A vibration damping device for use with a downhole tool having a tool axis and a drill string component (DSC), may comprise an inertia ring rotatably mounted on the DSC and including at least one cutout defining a chamber therein such that the DSC forms an end wall of the chamber, and a leaf spring disposed in the chamber, the leaf spring having first and second spring ends, the first end being attached to the inertia ring or the DSC such that relative rotation between the inertia ring and the DSC distorts the leaf spring. The second spring end may engage the other of the inertia ring or the DSC. A fluid may be included in the chamber and the spring may divide the chamber into two portions, so that relative rotation between the inertia ring and the DSC distorts the leaf spring and varies the volumes of the portions.

A joystick device including a hollow housing having an endless boundary structure and a ceiling structure with an opening; a control-stick having a head portion and a stem portion, the hollow housing surrounding the stem portion with the head portion outside the hollow housing; and a plurality of biasing curved arm members extending outwardly from the stem portion and movable with the control-stick as a whole relative to the hollow housing along a plane at least substantially perpendicular to the stem portion. Each of the plurality of biasing curved arm members having a curved segment with a convex side directed towards a respective corresponding portion of the endless boundary structure so as to bias the stem portion when the control-stick is being moved towards said portion. The plurality of biasing curved arm members being distributed around the stem portion so as to cooperate with each other to centre the control-stick.

A vibration reduction shaft includes a cylindrical outer shaft having an inner hollow portion, in which the outer shaft includes: a first member (110) and a second member (120) which are disposed to be spaced apart from each other in a longitudinal direction of the shaft; and a vibration reduction region (150) which is disposed between the first member and the second member, and multiple connecting members (151), which connect the first member and the second member in an axial direction, are disposed to be spaced apart from one another within the vibration reduction region.

Blade and spring damper apparatus for use with vehicle torque converters are disclosed. A disclosed vehicle torque converter includes a housing, a hub, a clutch including a piston in the housing, and a damper assembly operatively interposed between the clutch and the hub. The damper assembly includes a blade damper having a blade and a roller engaging the blade. Movement of the roller relative to the blade bends and unbends the blade. The damper assembly also includes a spring damper connected to the blade damper. The spring damper includes a first spring damper portion, a second spring damper portion, and a spring between the first and second spring damper portions. Movement of the first spring damper portion relative to the second spring damper portion compresses and decompresses the spring. The blade damper and the spring damper, together, are configured to dampen a torsional vibration received by the housing when the clutch is engaged.

A gear mechanism for a fishing reel includes a drive gear, a handle, and a vibration damper. The drive gear includes a gear having a prescribed gear diameter, and a drive gear shaft rotated together with the gear and having a smaller dimension than the prescribed gear diameter. The handle rotates the drive gear shaft. The vibration damper is disposed between the drive gear shaft and the handle, and dampens the transmission of the vibration of the drive gear.