Lord Corporation

Kenneth Alan St Clair

Robert H Marjoram

Mark R Jolly

J David Carlson

Douglas Edward Ivers

Michael J Chrzan

Donald R Prindle

William J McMahon

K Andrew Kintz

Steve Koester

Steve C Southward

David M Catanzarite

Stephen F Hildebrand

Kenneth R Boone

Stephen P Koester

Gregory Ericksen

William C Hardin

Mariane Hontz

The controllable suspension system includes a strut with a magnetorheological fluid damper. The magnetorheological fluid damper includes a longitudinal damper tubular housing having a longitudinally extending axis and an inner wall for containing magnetorheological fluid. The damper includes a piston head movable within the damper tubular housing along a longitudinal length the housing, with the damper piston head providing a first upper variable volume magnetorheological fluid chamber and a second lower variable volume magnetorheological fluid chamber, with a fluid flow gap between the upper and lower fluid chambers, the damper piston having a longitudinal piston rod for supporting the piston head within the housing, with the piston supported within the housing with a piston rod bearing assembly disposed between the housing and the rod, with the piston rod bearing assembly having a piston rod bearing seal interface.

Controllable vehicle suspension system with a controllable magnetorheological fluid strut

A controllable brake includes a housing and a rotor supported on a shaft. The rotor is housed within a chamber containing a field controllable material which is acted upon by a magnetic field generator to impede movement of the rotor. The shaft is supported by bearings. The controllable brake housing defines a second housing chamber adapted to enclose means for monitoring and/or controlling the brake and in this way, an integrated, compact controllable brake is provided.

Brake with field responsive material

A magneto-rheological fluid damper includes a damper body having a reservoir for a magneto-rheological fluid, a piston rod, a piston rod guide disposed within the damper body, where the piston rod guide has a passage therein for receiving the piston rod. The magneto-rheological fluid damper further includes at least a first piston rod seal and at least a second piston rod seal arranged to seal between the piston rod guide and the piston rod. The magneto-rheological fluid damper further includes a fluid chamber defined between the piston rod guide and the piston rod, the fluid chamber being in communication with the reservoir. The magneto-rheological fluid damper further includes a piston rod guide filter arranged in a communication path between the fluid chamber and the reservoir to filter particulates out of the magneto-rheological fluid entering the fluid chamber. The magneto-rheological fluid damper further includes an accumulator arranged between the piston rod guide and the damper body.

Magneto-rheological dampers for semi-active suspension systems

A damper device comprising a first mode having a first level of damping, a second mode having a second level of damping corresponding to a predetermined function, a sensor system having a first output corresponding to a normal position and a second output corresponding to an end stop approaching position, and a control system operable for receiving the first output and the second output and executing the first mode and the second mode. The damper device is operable in the first mode when the control system receives the first output and is operable in the second mode when the control system receives the second output. A controllable suspension system comprising a damper device, a magnetic probe, a sensor system comprising at least one position sensor operable for sensing the position of the magnetic probe, and a control system electronically connected to the sensor system and the damper device, wherein the control system is operable for receiving an output from the sensor system and executing a predetermined function to control the damper device. Electric signals are supplied to the damper device from the control system during system operation to provide damping sufficient to prevent end stop collisions.

Adjustable damping control with end stop

The controllable suspension system includes a strut with a magnetorheological fluid damper. The magnetorheological fluid damper includes a longitudinal damper tubular housing having a longitudinally extending axis and an inner wall for containing magnetorheological fluid. The damper includes a piston head movable within the damper tubular housing along a longitudinal length the housing, with the damper piston head providing a first upper variable volume magnetorheological fluid chamber and a second lower variable volume magnetorheological fluid chamber, with a fluid flow gap between the upper and lower fluid chambers with a piston head fluid flow interface length HL, the damper piston having a longitudinal piston rod for supporting the piston head within the housing, with the piston supported within the housing with a piston rod bearing assembly disposed between the housing and the rod, with the piston rod bearing assembly having a piston rod bearing seal interface length BL, wherein contact between the piston head and the damper tubular housing inner wall is inhibited.

A controllable brake includes a rotor supported on one shaft end. The rotor is housed within a chamber containing a field controllable material which is acted upon by a magnetic field generator to change the rheology of the material and thereby impede movement of the rotor. The shaft is supported by two bearings which, in combination with the housing define a second housing chamber adapted to enclose means for monitoring and/or controlling the brake and in this way, an integrated, compact controllable brake is provided.

A method for limiting endstop collisions when non-typical inputs are experienced and also when the seat is leveled at a position above or below the normal leveling zone limits. According to the method of the invention a temporary or transient control method referred to as rebound control method causes a large damping force to be applied by the seat suspension system in response to non-typically large inputs. The large damping force is applied until a duration timer timesout. Also according to the invention, a level control algorithm provides additional damping when the seat is leveled outside the normal leveling zone. The degree of additional damping provided is a function of the distance the seat exceeds the normal leveling zone.

Method for limiting endstop collisions in semi-active seat suspension systems

In a seat suspension system, a method for adjusting the gain applied to a control signal to accommodate for large variations in rider weight and input severity and thereby provide rider comfort over a wider range of conditions than is possible with fixed gains or tunings. The method of the present invention is adaptable to changes in system operating conditions.

Method for adjusting the gain applied to a seat suspension control signal

An Adaptive Off-state (AO) control method (,) for use in conjunction with a suspension system (,) including a controllable damper (,) interconnecting relatively moveable members (,) to reduce the transmission of vibrational forces therebetween. Such suspension systems (,) are switchable between alternative on- and an off-state in accordance with a primary control method (,) and/or a secondary override control method (,). Sensors (,) monitor the parameters of the suspension system (,), such as the displacement, velocity, and acceleration of the moveable members (,). Damper command signals (,) are provided to the damper (,) in the on-state (,) to adjust the damping characteristics thereof. In the off-state, the damping signal in conventional systems is approximately zero or a constant relatively low magnitude. According to the present adaptive off-state control method (,), the off-state damping signal (,) to the controllable damper (,) is modulated over time to make the off-state damping a function of the system inputs. In a preferred embodiment, the modulation is a function of the real time or time-averaged input disturbances to the system (,). In an alternative embodiment, the modulation is derived from a user switch (,) that imparts a user variable Off-State Gain (OSG) to the off-state damping signal (,) based on operator perceived ride characteristics.

Adaptive off-state control method

A controllable valve assembly (18) applicable in Magnetorheological (MR) fluid devices (20), such as MR mounts and MR dampers. The valve assembly (18) includes a valve body (32) having a magnetic circuit (40) contained therein which carries magnetic flux .phi., a controllable passageway (42) within the magnetic circuit (40), a MR (magnetically controlled) fluid (44) including soft-magnetic particles in a liquid carrier contained in the controllable passageway (42), a magnetic flux generator, such as a wound wire coil (46), generating magnetic flux .phi. which is directed through the MR fluid (44) in the controllable passageway (42) thereby generating 'rheology' changes causing restriction in flow of MR fluid (44) therethrough. In one aspect, a one-way check valve (34) is operative with a passive passageway (36) which is arranged in parallel relationship to the controllable passageway (42) provides 'asymmetric' damping across the controllable valve (18) creating higher pressure differentials in a first direction and a lower in a second direction without 'rapidly switching' the current to the coil (46). In another aspect, 'asymmetric' damping is provided by a 'changeable gap' formed by a moveable wall portion of the controllable passageway (42). In a third aspect, a first controllable passageway provides controllable flow in a first direction and a second controllable passageway provides controllable flow in a second direction, thereby provide 'asymmetry.' In a fourth aspect, 'asymmetry' is provides by a 'variable magnetic short' which changes magnetic circuit reluctance dependent on flow direction.

Two-way magnetorheological fluid valve assembly and devices utilizing

A controllable valve assembly (18) applicable in Magnetorheological (MR) fluid devices (20), such as MR mounts and MR dampers. The valve assembly (18) includes a valve body (32) having a magnetic circuit (40) contained therein which carries magnetic flux .PHI., a controllable passageway (42) within the magnetic circuit (40), a MR (magnetically controlled) fluid (44) including soft-magnetic particles in a liquid carrier contained in the controllable passageway (42), a magnetic flux generator, such as a wound wire coil (46), generating magnetic flux .PHI. which is directed through the MR fluid (44) in the controllable passageway (42) thereby generating 'rheology' changes causing restriction in flow of MR fluid (44) therethrough. In one aspect, a one-way check valve (34) is operative with a passive passageway (36) which is arranged in parallel relationship to the controllable passageway (42) provides 'asymmetric' damping across the controllable valve (18) creating higher pressure differentials in a first direction and a lower in a second direction without 'rapidly switching' the current to the coil (46). In another aspect, 'asymmetric' damping is provided by a 'changeable gap' formed by a moveable wall portion of the controllable passageway (42). In a third aspect, a first controllable passageway provides controllable flow in a first direction and a second controllable passageway provides controllable flow in a second direction, thereby provide 'asymmetry.' In a fourth aspect, 'asymmetry' is provides by a 'variable magnetic short' which changes magnetic circuit reluctance dependent on flow direction.

A controllable secondary suspension system (20) for vehicle cabs (18) and the like which flexibly suspends and controls movement of the vehicle's cab (22) relative to the vehicle's frame (24). The system (20) includes at least one flexible support (26), which are preferably two spaced apart air springs flexibly suspending the cab (22) relative to the frame (24), at least one controllable fluid damper, and preferably two spaced-apart controllable fluid dampers, such as Magnetorheological (MR) fluid dampers (28, 28'), interconnected between the cab (22) and the frame (24). In one aspect, the system (20) may include at least one sensor, such as a relative position sensor (30), for providing relative vibration information between the cab (22) and the frame (24), and a controller (36) for processing the relative vibration information to determine current to be supplied to the controllable fluid damper (28) to control the degree of damping thereof. Signals from additional sensors, such as a speed sensor (32), steering angle sensor (34), brake sensor (46), throttle position sensor (48), and vertical and lateral acceleration sensors (40, 44) may be used to enhance control. Roll, pitch, lurch and ride may be simultaneously or independently controlled.

Controllable cab suspension

A method for controlling end stop collisions in electro-mechanical systems including dampers or actuators. In a first aspect, a velocity-squared control method determines an end stop control signal (V.sub.end stop) based, at least in part, upon a square of the relative velocity (V.sub.inst). Preferably, the displacement (.delta..sub.end) to the end stop is also used to derive the end stop control signal (V.sub.end stop). In another aspect, a snubber control method is employed which produces a snubber control signal (V.sub.snub) based, at least in part, upon a continuous function of a snubber incursion distance (.delta..sub.z) within a snubber zone (Z). Preferably, the velocity-squared end stop and the snubber control methods operate together. When used in conjunction with an end stop control method, the snubber control method prevents end stop collisions for cases where the end stop control algorithm alone would not. Either of the end stop methods (the velocity-squared end stop control method or the snubber control method) may be used alone, in combination with each other, or in combination with a primary control method.

End stop control method

A controllable vibration apparatus having an electrical connection to a controllable valve made through a single-strand electrical conductor. In one embodiment, the piston and rod are preferably used as the source of ground or return electrical path. An axially compressed sealing element provides radial sealing against the conductor. An accumulator including a flexible diaphragm provides separation of fluid and accumulator chambers. In magnetorheological (MR) fluid dampers, a special sealing system including a relationship between piston rod surface finish and particle size is provided. A surface treated metal bushing is used with a lip seal to prevent escape of fluid and support side loads. The controllable valve can be formed from top and bottom pole pieces spaced from an outer ring to define a passageway. The pole and ring are preferably secured together by non-magnetic bridging elements. Preferably, the coil assembly is configured with integral axially-extending pins for ease of connection. Push-on connectors preferably make the connection between the conductor and pins. In a two single-strand conductor version, one single-strand carries the incoming current and the other the outgoing current.

Growing community of inventors

Cary, NC, United States of America

Kenneth Alan St Clair