Abstract: A system and method for monitoring the composition of a magnetically permeable material, where the system comprises a first container containing a volume of magnetically permeable material; a flow path for flowing the magnetically permeable material out of the container; a sensor for determining the inductance of the magnetically permeable material; and a sensor for determining the density of the magnetically permeable material. The sensors for determining the density and inductance of the magnetically permeable material are flow connected to the flow path.

Abstract: A magnetically actuated motion control device includes a housing defining a cavity and including a slot therethrough. A movable member is located within the cavity and is movable relative to the housing. A magnetic field generator located on either the housing or the movable member causes the housing to press against the movable member to develop a friction force. The flux caused by the magnetic field flows through the housing, the movable member and at least one pole located along the movable member. The at least one pole comprises a first portion having a first axial dimension and a second portion having a second axial dimension where the first axial dimension is greater than the second axial dimension and as a result the magnetic flux through the second portion of the at least one pole has a greater magnitude than the magnetic flux through the first portion of the pole.

Abstract: A system that includes a magnetically actuated motion control device comprising a housing defining a cavity and including a slot therethrough. A movable member is located within the cavity and is movable relative to the housing. A magnetic field generator located on either the housing or the movable member causes the housing to press against the movable member to develop a friction force.

Abstract: A joint member for selectively joining first and second members, said joint member comprising a first coupling member comprising a volume of field responsive material and a second coupling member comprising a field generating member for selectively applying a field across the field responsive material, the joint member also comprising means for selectively moving the field responsive material toward and away from the field generating means.

Abstract: An apparatus comprising a frame; a member movable relative to said frame; a damping device interconnected between the frame and the movable member; a controller for activating said damper to generate a damping condition at a predetermined member operating condition; and system for activating the damping device at a predetermined operating condition of the moving member during a loss of power to the apparatus. The damping device may comprise a field controllable damper that includes a volume of field controllable fluid, which may in turn comprise magnetorheological fluid for example. The rheology of the field controllable fluid is effected during the application of said field.

Abstract: A system that includes a magnetically actuated motion control device comprising a housing defining a cavity and including a slot therethrough. A movable member is located within the cavity and is movable relative to the housing. A magnetic field generator located on either the housing or the movable member causes the housing to press against the movable member to develop a friction force.

Abstract: The invention provides a magnetorheological grease composition which contains magnetic-responsive particles, a carrier fluid and a thickening agent. The composition according to the invention contains an effective amount of thickening agent to provide a composition of proper consistency with good properties and little settling of the magnetic-responsive particles.

Abstract: A system and method for monitoring the composition of a magnetically permeable material, where the system comprises a first container containing a volume of magnetically permeable material; a flow path for flowing the magnetically permeable material out of the container; a sensor for determining the inductance of the magnetically permeable material; and a sensor for determining the density of the magnetically permeable material. The sensors for determining the density and inductance of the magnetically permeable material are flow connected to the flow path.

Abstract: A chair height adjustment mechanism includes an energy storage unit which has a compressible fluid. This compressible fluid allows the compressible fluid displaced by the piston rod entering the cylinder, to store energy for subsequent use as the chair seat is raised. This fluid may be of the type that has a dual phase at room temperature such that increase in pressure on the compressible fluid causes a portion of that compressible fluid to transition from gaseous phase to liquid phase. This makes the energy storage unit a constant force spring. The features of this constant force spring may be used in a conventional piston cylinder, shock absorbing device, as well.

Abstract: Magnetorheological fluid concentrates are provided which contain a substantially dry mixture of magnetic-responsive powder and a thixotropic agent. The concentrates may be mixed with an aqueous or an organic carrier fluid to form magnetorheological fluids.

Abstract: A magnetorheological (MR) device (20) including settling stability. The MR fluid device (20) includes a housing (22) including a hollow (30), a moving element (26) contained within the hollow (30), the housing (26) and moving element (26) cooperating to form a working section (36) and a chamber (32) within the hollow (30), a MR fluid (38) contained within the working section (36) and the chamber (32), a coil (40) or the like for generating a magnetic field to act upon the MR fluid (38) contained within the working section (36) to cause a rheology change therein, and a magnet (25) or electromagnet (31) generating a low-level magnetic field to act upon a substantial portion of the MR fluid (38) contained in the chamber (32) to minimize settling of the particles in the MR fluid. Linear and rotary acting embodiments are included.

Abstract: A controllable medium device for resisting movement (rotary, linear, or sliding) between two relatively moveable members includes a first member and a second member coupled for relative movement having a working space between them, and a controllable medium retaining structure, for example, an absorbent matrix, to hold a controllable medium only in the working space. A field generating coil is mounted to one of the first and second members to generate a field acting on the first and second members and the controllable medium in the working space. The rheology change in the medium produced by the field results in resistance to relative movement of the first and second members. A device according to the invention may be used in apparatus, such as washing machines, exercise equipment, air supported tables, and a range of other apparatuses that would benefit from controlled damping or braking.

Abstract: A magnetically actuated motion control device includes a housing defining a cavity and including a slot therethrough. A movable member is located within the cavity and is movable relative to the housing. A magnetic field generator located on either the housing or the movable member causes the housing to press against the movable member to develop a friction force.

Abstract: A haptic interface system or force feedback system having a magnetically-controllable device that provides resistance forces opposing movement. The magnetically-controllable device is adapted for use with a force feedback computer system to provide force feedback sensations to the system's operator. The magnetically-controllable device contains a magnetically-controllable medium beneficially providing variable resistance forces in proportion to the strength of an applied magnetic field. The system further comprises a controller that executes an interactive program or event, a video display, and a haptic interface device (e.g. joystick, steering wheel) in operable contact with an operator for controlling inputs and responses to the interactive program.

Abstract: A joint member for selectively joining first and second members, said joint member comprising a first coupling member comprising a volume of field responsive material and a second coupling member comprising a field generating member for selectively applying a field across the field responsive material, the joint member also comprising means for selectively moving the field responsive material toward and away from the field generating means.

Abstract: A controllable damper for resisting movement between two relatively moveable members includes a first member and a second member coupled for relative movement having a working space between them, and a controllable medium retaining structure, for example, an absorbent matrix, to hold a controllable medium in the working space. A field generating coil is mounted to one of the first and second members to generate a field acting on the first and second members and the controllable medium in the working space. The rheology change in the medium produced by the field results in resistance to relative movement of the first and second members. According to a preferred embodiment, transmission is included to convert linear motion of a first component to rotary motion of the second member. The transmission allows amplification of the relative speed between the first and second members.

Abstract: A haptic interface system or force feedback system having a magnetically-controllable device that provides resistance forces opposing movement. The magnetically-controllable device is adapted for use with a force feedback computer system to provide force feedback sensations to the system's operator. The magnetically-controllable device contains a magnetically-controllable medium beneficially providing variable resistance forces in proportion to the strength of an applied magnetic field. The system further comprises a computer system that runs an interactive program or event, a video display display, and a haptic interface device (e.g. joystick, steering wheel) in operable contact with an operator for controlling inputs and responses to the interactive program.

Abstract: A haptic interface system or force feedback system having a magnetically-controllable device that provides resistance forces opposing movement. The magnetically-controllable device is adapted for use with a force feedback computer system to provide force feedback sensations to the system's operator. The magnetically-controllable device contains a magnetically-controllable medium beneficially providing variable resistance forces in proportion to the strength of an applied magnetic field. The system further comprises a controller that executes an interactive program or event, a video display, and a haptic interface device (e.g. joystick, steering wheel) in operable contact with an operator for controlling inputs and responses to the interactive program.

Abstract: An interlock mechanism is provided which includes a controllable fluid within a hydraulic link. The controllable fluid, preferably comprising a magnetorheological fluid, is disposed within the interlock mechanism. The viscosity of the fluid can be changed to allow the interlock mechanism to be actuated. A fluid control means, such as a magnet assembly, is used to control the fluid.