Abstract: As disclosed herein, an apparatus for adjusting a tension of a headband of a head-mounted display (HMD) is provided. The apparatus may include a base plate including a stationary ratchet drum. The apparatus may include a rotating cap positioned over at least the stationary ratchet drum to define an internal space therebetween. The rotating cap may include multiple walled structures projecting from an inner surface of the rotating cap and into the internal space. The apparatus may include a ratchet positioned in the internal space. The ratchet may include multiple pawls. Each pawl may include a head. The head may include a first protrusion projecting transversely to the head and a second protrusion projecting transversely to the first protrusion. The first protrusion may be received within a corresponding walled structure, and the corresponding walled structure may be configured to guide a pivoting movement of the pawl.

Abstract: The present invention relates to an electromechanical battery comprising a single pole-pair Halbach array of permanent magnets incorporated into an annular flywheel, which together comprise a rotor assembly, a means for levitating the rotor assembly using a “double-lift” attractive magnetic levitator under active control, and a means for actively stabilizing the spinning rotor assembly by interaction with the fringe fields of the Halbach array.

Abstract: The present invention relates to an electromechanical battery comprising a single pole-pair Halbach array of permanent magnets incorporated into an annular flywheel, which together comprise a rotor assembly, a means for levitating the rotor assembly using a “double-lift” attractive magnetic levitator under active control, and a means for actively stabilizing the spinning rotor assembly by interaction with the fringe fields of the Halbach array.