Abstract: A descent control device for controlling rotational motion of an object includes: at least one drive assembly for rotationally engaging the rotating object; a first substantially planar ferromagnetic moving element in rotationally locked engagement with at least one drive assembly and comprising at least one recess formed in a surface thereof having at least one magnet fixedly disposed therein; a second substantially planar ferromagnetic moving element in rotationally locked engagement with at least one drive assembly, and comprising at least one recess formed in a surface thereof having at least one magnet fixedly disposed therein; and at least one conducting plate disposed proximate the first and second moving elements. A magnetic field may be induced by rotational movement of the first or second moving element relative to at least one conducting plate in a direction to oppose acceleration of at least one drive assembly as it rotationally engages the object.

Abstract: A descent control device for controlling rotational motion of an object includes: at least one drive assembly for rotationally engaging the rotating object; a first substantially planar ferromagnetic moving element in rotationally locked engagement with at least one drive assembly and comprising at least one recess formed in a surface thereof having at least one magnet fixedly disposed therein; a second substantially planar ferromagnetic moving element in rotationally locked engagement with at least one drive assembly, and comprising at least one recess formed in a surface thereof having at least one magnet fixedly disposed therein; and at least one conducting plate disposed proximate the first and second moving elements. A magnetic field may be induced by rotational movement of the first or second moving element relative to at least one conducting plate in a direction to oppose acceleration of at least one drive assembly as it rotationally engages the object.

Abstract: A magnetic descent control device is disclosed. The device comprises an input shaft affixed to a rotating driven sheave acting as a drive assembly, which grips a cable guiding the descent path of a body carrying cage. The input shaft has a shoulder upon which rests a rotor. The rotor is encased within a front and back enclosure of conductive material. Disposed along at least one surface of the rotor and/or at least one of the conductors, is a series of magnets such that rotation of the rotor relative to the conductors creates relative motion between the magnets' magnetic field and the conductor inducing eddy currents in the conductor that oppose the magnetic field creating a rotational braking force. As a result, very precise and/or controllable descent may be obtained over a broad range of descent angles and/or distances with little or no mechanical wear or risk of overheating. Preferably, the sheave gripping the cable may have a circumferential groove to better improve traction and grip of the cable.

Abstract: A magnetic descent control device is disclosed. The device comprises an input shaft affixed to a rotating driven sheave acting as a drive assembly, which grips a cable guiding the descent path of a body carrying cage. The input shaft has a shoulder upon which rests a rotor. The rotor is encased within a front and back enclosure of conductive material. Disposed along at least one surface of the rotor and/or at least one of the conductors, is a series of magnets such that rotation of the rotor relative to the conductors creates relative motion between the magnets' magnetic field and the conductor inducing eddy currents in the conductor that oppose the magnetic field creating a rotational braking force. As a result, very precise and/or controllable descent may be obtained over a broad range of descent angles and/or distances with little or no mechanical wear or risk of overheating. Preferably, the sheave gripping the cable may have a circumferential groove to better improve traction and grip of the cable.