Abstract: A screen having louvers rotatable about parallel axes under the control of magnetic fields and attached to permanent magnets contained in a magnetically permeable housing so dimensioned relative to the spacing between adjacent magnets that each magnet exerts a stabilizing torque on like magnets of neighboring louvers to maintain a parallel attitude between all of the louvers.

Abstract: An electromagnetically operated screen having a plurality of louvers which are provided with permanent magnets for maintaining the louvers latched shut when in a closed attitude without the consumption of energy.

Abstract: A link suspension permitting limited rotation of a rotor in response to a magnetic control field uses a permanent magnet and support means having two contacting narrow concave curvilinear surfaces.

Abstract: A link suspension permitting limited rotation of a rotor in response to a magnetic control field uses a permanent magnet and support means having two contacting narrow concave curvilinear surfaces.

Abstract: Apparatus for holding a series of permanent magnet rotors having parallel transversely spaced coplanar rotational angles firmly at any of a wide range of desired angles without consumption of energy, the angles being linearly adjustable independently of rotor spacing and with constant torque sensitivity, by mechanically linking each rotor to an adjacent rotor to form pairs and arranging the magnetic axes mutually perpendicular and perpendicular to the axes of rotation, coupling each rotor to a direct magnetic control field component perpendicular to the plane which is common to the rotor axes and varying the amplitude ratio of the field components coupled to the rotors of a linked pair according to the tangent of a control angle to turn the rotors through a corresponding angle.

Abstract: Apparatus which has a permanent magnet rotor magnetically coupled to a control field permanent magnet, the magnets being rotatable about respective rotational axes of support that are perpendicular to one another. The magnetic axis of each magnet is perpendicular to the rotational axis of that magnet, so that the rotor magnet changes in attitude about its rotational axis in response to a change in the magnitude and sense of the control field component perpendicular to the rotational axis of the rotor magnet. Such a change of the perpendicular control field component is caused by turning the control field magnet about its rotational axis through motor-driven reduction gearing including a worm and gear combination which holds the rotor magnet at its adjusted attitude after the motor is deenergized.