Patents by Inventor Keith O. Stuart

Keith O. Stuart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5782454
    Abstract: An electromagnetically actuator is disclosed having an electromagnet, a core element, the core element having a normally biased initial spaced apart first position distal from the electromagnet when the electromagnet is off and a second stop position proximal from the electromagnet when the electromagnet is on, a first resilient member adapted to bias said core element in the normally biased first position, and a second resilient member adapted to bias the electromagnet away from the core. The first resilient member is more resilient than the second resilient member. Therefore, the core approaches the electromagnet when the electromagnet is on until the core reaches the fixed stop position, and the electromagnet subsequently approaches the core to the fixed stop position. The actuator may further include an adjustment member that engages the electromagnet so as to control the pressure of the electromagnet against the second resilient member, whereby the axial position of the electromagnet is controlled.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: July 21, 1998
    Assignee: Aura Systems, Inc.
    Inventors: Dennis C. Bulgatz, Fernando B. Morinigo, Christopher Sortore, Keith O. Stuart
  • Patent number: 5768395
    Abstract: A field coil actuator includes a magnetic flux conductive material case, an electrical current conductive field coil and two electrical current conductive moving coils uniquely arranged. The case has a first surface and a continuous channel disposed in said first surface. The channel has a pair of opposing walls. The field coil is disposed within the channel between the walls so that a gap remains between the walls above the field coil and another gap remains between the walls below the field coil. When a current is induced in the field coil, magnetic flux is developed across the gaps. The flux is confined substantially normal to the walls of the channel. The electrical current conductive moving coils are each disposed moveably in one of the gaps such that an electrical current in the coil develops a Lorentz force on each of the coils in a direction substantially normal to the current in the moving coil and the magnetic flux to displace the moving coil in response to the current in the moving coil.
    Type: Grant
    Filed: June 9, 1997
    Date of Patent: June 16, 1998
    Assignee: Aura Systems, Inc.
    Inventors: Keith O. Stuart, Dennis C. Bulgatz
  • Patent number: 5548263
    Abstract: An electromagnetically actuator is disclosed having an electromagnet, a core element, the core element having a normally biased initial spaced apart first position distal from the electromagnet when the electromagnet is off and a second stop position proximal from the electromagnet when the electromagnet is on, a first resilient member adapted to bias said core element in the normally biased first position, and a second resilient member adapted to bias the electromagnet away from the core. The first resilient member is more resilient than the second resilient member. Therefore, the core approaches the electromagnet when the electromagnet is on until the core reaches the fixed stop position, and the electromagnet subsequently approaches the core to the fixed stop position. The actuator may further include an adjustment member that engages the electromagnet so as to control the pressure of the electromagnet against the second resilient member, whereby the axial position of the electromagnet is controlled.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: August 20, 1996
    Assignee: Aura Systems, Inc.
    Inventors: Dennis C. Bulgatz, Fernando B. Morinigo, Christopher Sortore, Keith O. Stuart
  • Patent number: 5536984
    Abstract: A voice coil actuator includes a magnetic flux conductive material core, a magnet and an electrical current conductive coil. The core has a first surface and a continuous channel disposed in said first surface. The channel has a pair of opposing walls. The magnet is disposed in intimate contact with a first one of said walls and spaced from a second one of said walls so that a gap remains between the magnet and the second one of the walls. The magnet has a first face of a first magnetic polarity facing the first one of the walls and a second face of a second, opposite magnetic polarity facing the gap. The magnet is further spaced from a bottom of the channel so that magnetic flux is substantially normal from the second face across said gap to the second one of the walls.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: July 16, 1996
    Assignee: Aura Systems, Inc.
    Inventors: Keith O. Stuart, Dennis C. Bulgatz
  • Patent number: 5434458
    Abstract: A voice coil actuator includes a magnetic flux conductive material core, a magnet and an electrical current conductive coil. The core has a first surface and a continuous channel disposed in the first surface. The channel has a pair of opposing walls. The magnet is disposed in intimate contact with a first one of the walls and spaced from a second one of the walls so that a gap remains between the magnet and the second one of the walls. The magnet has a first face of a first magnetic polarity facing the first one of the walls and a second face of a second, opposite magnetic polarity facing the gap. The magnet is further spaced from a bottom of the channel so that magnetic flux is substantially normal from the second face across the gap to the second one of the walls.
    Type: Grant
    Filed: August 5, 1994
    Date of Patent: July 18, 1995
    Assignee: Aura Systems, Inc.
    Inventors: Keith O. Stuart, Dennis C. Bulgatz
  • Patent number: 5355108
    Abstract: A compressor having an electromagnetically actuated valve is disclosed. The movement of the compressor's piston is controlled by an electromagnetically actuated valve. The valve includes an electromagnetic element having a core and a coil, and an armature. The core has a surface and an opening at the surface extending through the core. The surface also includes a continuous channel extending around the opening. The channel has a top portion of frustroconical cross-section and a bottom portion. The coil is disposed in the bottom portion. The armature element has a raised portion dimensioned to be received within the top portion of the channel. The valve shaft is disposed within the opening of the electromagnetic element and is connected to the armature. The compressor piston is connected to one end of the shaft. A support spring is disposed within the opening of the electromagnetic element, and extends from the retaining bar to the upper surface of the cylinder.
    Type: Grant
    Filed: December 9, 1992
    Date of Patent: October 11, 1994
    Assignee: Aura Systems, Inc.
    Inventors: Fernando B. Morinigo, Keith O. Stuart
  • Patent number: 5354185
    Abstract: A compressor is disclosed having an electromagnetic actuator for driving the piston in the compression cylinder. The actuator includes an electromagnetic element having a core and a coil. The core has an electromagnet surface and a channel extending through the core. The coil is disposed in the channel. An axially reciprocating armature element is interconnected with the piston. The armature element defines an axial stroke having a stroke midpoint and a stroke peak. The armature element also has an armature surface dimensioned to align with and correspond to the electromagnet surface at the stroke peak. The actuator also includes a primary spring disposed on one end of the armature element for biasing the armature from movement in an axial direction. A secondary spring is disposed on the opposing end of the armature element and biases the armature from movement in an opposite axial direction. The armature is biased by the springs to resonate at a pre-determined frequency.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: October 11, 1994
    Assignee: Aura Systems, Inc.
    Inventors: Fernando B. Morinigo, Keith O. Stuart
  • Patent number: 5352101
    Abstract: A compressor having an electromagnetically actuated valve is disclosed. The movement of the compressor's piston is controlled by an electromagnetically actuated valve. The valve includes an electromagnetic element having a core and a coil, and an armature. The core has a surface and an opening at the surface extending through the core. The surface also includes a continuous channel extending around the opening. The channel has a top portion of frustroconical cross-section and a bottom portion. The coil is disposed in the bottom portion. The armature element has a raised portion dimensioned to be received within the top portion of the channel. The valve shaft is disposed within the opening of the electromagnetic element and is connected to the armature. The compressor piston is connected to one end of the shaft. A support spring is disposed within the opening of the electromagnetic element, and extends from the retaining bar to the upper surface of the cylinder.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: October 4, 1994
    Assignee: Aura Systems, Inc.
    Inventors: Fernando B. Morinigo, Keith O. Stuart
  • Patent number: 5341054
    Abstract: An electromagnetic actuator includes a magnetic flux conductive material housing, an electrical current conductive coil, a magnetic flux conductive material stationary core portion, a slideable core portion, and a pair of radially polarized magnetic flux developing elements. The coil is disposed in the housing coextensively adjacent to the housing's interior wall. The core is disposed within the housing and the coil and includes both the magnetic flux conductive stationary core portion and the slideable core portion. The slideable core portion is slideably received on the stationary core portion, and the magnetic flux developing elements are carried on the exterior wall of the slideable core portion in a facing relationship with the coil.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: August 23, 1994
    Assignee: Aura Systems, Inc.
    Inventors: Zeev Tal, Keith O. Stuart, Dennis C. Bulgatz
  • Patent number: 5325699
    Abstract: A linear electromagnetic actuator has it core mounted to a can body forming apparatus and its coil attached to re-draw sleeve of such apparatus. The actuator provides for the axial movement of the re-draw sleeve between its fully retracted position and its fully extended position. The re-draw sleeve and the coil are coaxially mounted to each other so that the force exerted on the re-draw sleeve is also coaxial. Once the re-draw sleeve is in its fully extended position, an electromagnet is turned on so that the re-draw sleeve exerts the requisite force on the can material preform. The electromagnet is mounted coaxially about the re-draw sleeve and exerts its force on a magnetic material ring mounted to the re-draw sleeve to hold the re-draw sleeve against the can material preform.
    Type: Grant
    Filed: February 18, 1993
    Date of Patent: July 5, 1994
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart
  • Patent number: 5321762
    Abstract: A voice coil actuator includes a magnetic flux conductive material core, a magnet and an electrical current conductive coil. The core has a first surface and a continuous channel disposed in said first surface. The channel has a pair of opposing walls. The magnet is disposed in intimate contact with a first one of said walls and spaced from a second one of said walls so that a gap remains between the magnet and the second one of the walls. The magnet has a first face of a first magnetic polarity facing the first one of the walls and a second face of a second, opposite magnetic polarity facing the gap. The magnet is further spaced from a bottom of the channel so that magnetic flux is substantially normal from the second face across said gap to the second one of the walls.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: June 14, 1994
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart
  • Patent number: 5307665
    Abstract: A linear electromagnetic actuator has its core mounted to a can body forming apparatus and its coil attached to re-draw sleeve of such apparatus. The actuator provides for the axial movement of the re-draw sleeve between its fully retracted position and its fully extended position. The re-draw sleeve and the coil are coaxially mounted to each other so that the force exerted on the re-draw sleeve is also coaxial. Once the re-draw sleeve is in its fully extended position, an electromagnet is turned on so that the re-draw sleeve exerts the requisite force on the can material preform. The electromagnet is mounted coaxially about the re-draw sleeve and exerts its force on a magnetic material ring mounted to the re-draw sleeve to hold the re-draw sleeve against the can material preform.
    Type: Grant
    Filed: July 10, 1992
    Date of Patent: May 3, 1994
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart
  • Patent number: 5309050
    Abstract: An electromagnetic actuator is disclosed having a case fabricated of a ferromagnetic material and defining a central axis, a core disposed coaxial with the central axis, and being in slideable engagement within the case. The core includes a first end portion, a second end portion, and a central portion. The actuator further includes magnetic flux developing element mounted coaxial with the central axis and a first and a second electrical current conductor coil. The first coil is mounted in a facing relationship with the first end portion of the core and the second coil is mounted in a facing relationship with the second end portion of the core. The coils are fabricated from a ferromagnetic material and are coaxial with the central axis. The coils have a cross-sectional length in a direction perpendicular to the central axis and a width of insulating space between the turns of the coil in a direction parallel to the central axis.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: May 3, 1994
    Assignee: Aura Systems, Inc.
    Inventors: Fernando B. Morinigo, Keith O. Stuart
  • Patent number: 5222714
    Abstract: An electromagnetically actuated valve is disclosed having an upper electromagnetic element and a lower electromagnetic element, each of the elements having a toroidal configuration or an annular configuration with a U-shaped cross-section. The elements each define a central chamber and a central channel. The upper and lower electromagnetic elements are in a mirrored relationship to each other. The valve also includes a core element having an annular horizontal cross-section and is disposed intermediate the upper and lower electromagnetic elements. A coil is disposed within the central channel of each of the electromagnetic elements. A valve stem is disposed within the central chamber of the electromagnetic elements. A spring is disposed within the central chamber of the electromagnetic elements for biasing the electromagnetic elements in a neutral position. A connecting plate connects the core elements to the valve stem.
    Type: Grant
    Filed: October 5, 1992
    Date of Patent: June 29, 1993
    Assignee: Aura Systems, Inc.
    Inventors: Fernando B. Morinigo, Keith O. Stuart
  • Patent number: 5212977
    Abstract: A linear electromagnetic actuator has it core mounted to a can body forming apparatus and its coil attached to re-draw sleeve of such apparatus. The actuator provides for the axial movement of the re-draw sleeve between its fully retracted position and its fully extended position. The re-draw sleeve and the coil are coaxially mounted to each other so that the force exerted on the re-draw sleeve is also coaxial. Once the re-draw sleeve is in its fully extended position, an electromagnet is turned on so that the re-draw sleeve exerts the requisite force on the can material perform. The electromagnet is mounted coaxially about the re-draw sleeve and exerts its force on a magnetic material ring mounted to the re-draw sleeve to hold the re-draw sleeve against the can material perform.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: May 25, 1993
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart
  • Patent number: 5187398
    Abstract: An electromagnetic actuator includes a magnetic flux conductive material case, an electrical current conductive coil, a magnetic flux conductive material core, and a pair of radially polarized magnetic flux developing elements. The coil is disposed in the case coextensively adjacent to its interior wall. The core is movably received within the chamber with motion of the core occurring between the first end and the second end of the case such that a first region of the core traverses the coil between its first end and its midpoint, and a second region of the core traverses the coil between its second end and its midpoint. A first one of the magnetic elements is carried by the first region and a second one of the magnetic elements is carried by the second region so that magnetic flux across the coil between the first region and the case is in a first direction, and magnetic flux across the coil between the second region and the case is in a second direction.
    Type: Grant
    Filed: March 23, 1992
    Date of Patent: February 16, 1993
    Assignee: Aura Systems, Inc.
    Inventors: Keith O. Stuart, Dennis C. Bulgatz
  • Patent number: 5099158
    Abstract: An improved electromagnetic actuator of the type comprising (a) a first assembly; (b) a second assembly movable relative to the first assembly along an axis of relative movement in response to a command signal, the second assembly comprising magnetic flux source means for defining radially directed flux both in an inward and outward direction relative to the axis of relative movement; (c) coil assembly means for defining at least two coil segments respectively disposed in the paths of the flux in the inward and outward directions; and (d) means for applying the command signal to the coil segments so that a current flows in one direction around the axis through the inward directed flux, and flows in the opposite direction around the axis through the outward directed flux so that the flux/current force applied between the first and second assemblies is additive. In accordance with one aspect of the invention flat magnets and flux focussing elements are used to provide the radially directed flux.
    Type: Grant
    Filed: March 26, 1990
    Date of Patent: March 24, 1992
    Assignee: Aura Systems, Inc.
    Inventors: Keith O. Stuart, Bradley J. Ashbrook, Dennis C. Bulgatz
  • Patent number: 4998441
    Abstract: A system for measuring a force applied to a mass so that the magnitude and direction of the force can be determined as well as the torque about three orthogonal axes. The system comprises an electromagnetic bearing support system for electromagnetically suspending the mass in a predetermined position and orientation relative to a three-dimensional coordinate system defining three mutually perpendicular axes. The forces applied to the mass are measured by measuring the force components of each applied force along one of the axes so that the one axis defines a reference axis. The force components in the direction of the two remaining force components are each measured at two locations along the reference axis. The roll of the mass about the reference axis is measured and the yaw and pitch of the mass about the two remaining axes is determined as a function of the two components in the direction of the of each of the two remaining axes.
    Type: Grant
    Filed: July 11, 1989
    Date of Patent: March 12, 1991
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart
  • Patent number: 4969662
    Abstract: The active damping system includes an electrical current conductive coil spatially fixed with respect to one of the sprung mass and unsprung mass of a vehicle and a magnetic element spatially fixed with respect to the other of the sprung mass and the unsprung mass. Relative motion is imparted between the coil and the magnetic element in response to relative motion between the sprung mass and the unsprung mass. This relative motion is in response to random input vibrations from a road surface. The magnetic element develops a magnetic flux intersecting the coil to develop and induced current through the coil wherein the induced current develops an electromotive force on the magnetic element opposing the relative motion to act as the active damping element. The active damping system also includes means for developing a control current through the coil to oppose motion of the sprung mass relative to the road surface occurring below a selected frequency.
    Type: Grant
    Filed: June 8, 1989
    Date of Patent: November 13, 1990
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart
  • Patent number: 4912343
    Abstract: An improved electromagnetic actuator assembly is described. The assembly comprises a magnetic circuit for defining radially directed flux both in an inward and outward direction, and a coil disposed in the flux paths and connect to receive a control signal so that a current can be applied in one direction through those portions of the coil disposed in the inward radially directed flux, and applied in the opposite direction through those portions of the coil disposed in the outwardly directed flux so that the flux/current products of the coil portions and associated flux are additive.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: March 27, 1990
    Assignee: Aura Systems, Inc.
    Inventor: Keith O. Stuart