Patents Assigned to Maxwell Laboratories, Inc.
  • Patent number: 5907472
    Abstract: A single cell, multi-electrode high performance double layer capacitor includes first and second flat stacks of electrodes adapted to be housed in a closeable two-part capacitor case which includes only a single electrolyte seal. Each electrode stack has a plurality of electrodes connected in parallel, with the electrodes of one stack being interleaved with the electrodes of the other stack to form an interleaved stack, and with the electrodes of each stack being electrically connected to respective capacitor terminals. A porous separator sleeve is inserted over the electrodes of one stack before interleaving to prevent electrical shorts between the electrodes. The electrodes are made by folding a compressible, low resistance, aluminum-impregnated carbon cloth, made from activated carbon fibers, around a current collector foil, with a tab of the foils of each electrode of each stack being connected in parallel and connected to the respective capacitor terminal.
    Type: Grant
    Filed: May 29, 1998
    Date of Patent: May 25, 1999
    Assignee: Maxwell Laboratories, Inc.
    Inventors: C. Joseph Farahmandi, John M. Dispennette, Edward Blank, Alan C. Kolb
  • Patent number: 5782253
    Abstract: A system is provided for removing material from a structure having at least one layer of the material formed on a substrate. The system includes a radiant energy source, such as a flashlamp, with an actively cooled reflector for irradiating a target area of a structure with radiant energy, preferably sufficiently intense in at least the visible and ultraviolet, to break or weaken chemical bonds in the material, and an abrasive blaster for impinging the material after irradiation with a cool particle stream, preferably including of CO.sub.2 particles, to remove the irradiated material and cool the substrate. The system may also include light sensors used in a feedback loop to control the removal process by varying the speed at which the radiant energy source is moved along the structure, the repetition rate of the source, the intensity of the source, the pulse width of the source and/or the distance between the source and the structure.
    Type: Grant
    Filed: March 2, 1994
    Date of Patent: July 21, 1998
    Assignees: McDonnell Douglas Corporation, Maxwell Laboratories, Inc.
    Inventors: Michael C. Cates, Richard R. Hamm, John D. Hoogerwerl, Michael W. Lewis, Wayne N. Schmitz
  • Patent number: 5751539
    Abstract: An improved ceramic feedthrough capacitor design which results in distinct advantages in EMI (electromagnetic interference) filtering and therapeutic waveform management for implantable defibrillators and pacemakers and the like. The invention provides ceramic capacitor electrode plate designs which provide both low impedance decoupling for EMI suppression, and, at the same time provide an isolated common ground point through a separate coupling capacitor for electrical isolation of the filtered circuit from the metal case (usually titanium) of the defibrillator or the like. Such an arrangement allows the defibrillator HV (high voltage) output pulse to the heart to be referenced lead to lead (including reverse polarity), or from either lead to a common floating ground point or to the titanium case. The primary application of the invention is directed to implantable defibrillators where the output pulse to the heart is typically high voltage (up to 750 volts) and of short duration (typically in the 10.times.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: May 12, 1998
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Robert A. Stevenson, Dick H. Ni
  • Patent number: 5621607
    Abstract: A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: April 15, 1997
    Assignee: Maxwell Laboratories, Inc.
    Inventors: C. Joseph Farahmandi, John M. Dispennette
  • Patent number: 5613509
    Abstract: An improved system and method are provided for removing material coatings or contaminants such as paints from a structure. The system and method include a radiant energy source, such as a flashlamp, for irradiating the target area of the structure with the radiant energy sufficient to initiate the pyrolysis and/or ablation of the coating or contaminant and a low temperature carbon dioxide stream which is directed at the target area to disperse the material from the structure, clean the exposed surface and cool the underlying substrate. The low temperature carbon dioxide stream is formed from a liquid carbon dioxide from a liquid carbon dioxide source which undergoes phase transition to yield a predetermined amount of low temperature carbon dioxide gas and carbon dioxide snow. The system and method eliminate the need for a carbon dioxide pelletizer, a carbon dioxide pellet transport hopper, and a compressed carrier gas which are used in related systems.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: March 25, 1997
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Alan C. Kolb, Leonard W. Braverman, Cyril J. Silberman, Richard R. Hamm, Michael C. Cates
  • Patent number: 5573307
    Abstract: A method and apparatus for blasting of hard rock using a highly insensitive energetic material ignited with a moderately high energy electrical discharge causing the fracturing and break up of the hard rock is provided. The blasting apparatus comprises a reusable blasting probe including a high voltage electrode and a ground return electrode separated by an insulating tube. The two electrodes of the blasting probe are in electrical contact with a continuous volume of highly insensitive yet combustible material such as a metal powder and oxidizer mixture. The metal particles within the metal powder and oxidizer mixture form a plurality of fusible metal paths between the high voltage electrode and the ground return when subjected to an electric current delivered from a large capacitor bank coupled to the high voltage electrode.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: November 12, 1996
    Assignee: Maxwell Laboratories, Inc.
    Inventors: G. Mark Wilkinson, Steven G. E. Pronko
  • Patent number: 5431105
    Abstract: An electrothermal chemical cartridge with a fuse of tapering cross section enables higher impulse energy to be imparted to a projectile by means of complete controlled burning of propellant. A long, narrow tube filled with propellant has a fuse on its inside surface with a cross section that tapers toward the discharge end, separated from the electrical ground of the cartridge casing by a layer of insulation sufficiently thin to be destroyed as the fuse ignites the propellant. A high-voltage electrode connected at the back end of the tube provides for application of a pulse of sufficient current density to ohmically heat or burn the fuse in a controlled fashion from the discharge end to the back end. Many such tubes can be bundled together in a large casing for wide barrel guns.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: July 11, 1995
    Assignee: Maxwell Laboratories, Inc.
    Inventor: G. Mark Wilkinson
  • Patent number: 5425570
    Abstract: Method and apparatus for plasma blasting comprises a capacitor bank for storing electrical charge to which is coupled an inductance which delivers the electric charge as a current through a switch to an explodable conductor comprising a portion of a probe. The explodable conductor is a ribbon helically wound on a cylindrical mandril, the ribbon having a given length to cross section ratio which is proportional to the square root of the ratio of the inductance to the capacitance in order to ensure efficient dissipation of an optimal amount of the electrical energy stored in the capacitance.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: June 20, 1995
    Assignee: Maxwell Laboratories, Inc.
    Inventor: Gregory M. Wilkinson
  • Patent number: 5390073
    Abstract: Dielectric materials having a high dipole moment density are provided. The high dipole moment density is achieved by the use of a substituted .alpha.-amino acid, such as N-trimethyl glycine and related homologues having nonpolar sidechain groups, with three alkyl substitutions on the nitrogen of the .alpha.-amino group. These molecules have a high dipole moment and small volume, allowing rapid rotation around the .alpha.-amino, carboxyl dipole. N-trimethyl glycine alone or in combination with one or more homologues is preferably provided as a solute in a liquid dielectric solution. Alternatively, these molecules are provided as substituents on a linear polymer.
    Type: Grant
    Filed: January 11, 1993
    Date of Patent: February 14, 1995
    Assignee: Maxwell Laboratories, Inc.
    Inventor: William G. McMillan
  • Patent number: 5333095
    Abstract: A feedthrough filter capacitor assembly and related installation method are provided for shielding a conductive terminal pin or lead of the type used, for example, in an implantable medical device such as a heart pacemaker or defibrillator, against passage of external interference signals. The feedthrough assembly includes a terminal pin subassembly having at least one terminal pin supported within a cylindrical conductive ferrule by a hermetically sealed insulator ring. The ferrule is adapted for mounting onto a conductive pacemaker housing, as by welding or brazing, to support the terminal pin for feedthrough passage to the housing interior. A co-axial filter capacitor is mounted at an inboard side of the pacemaker housing, with capacitor electrode plate sets coupled respectively to the pacemaker housing and to the terminal pin by a conductive adhesive or the like.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: July 26, 1994
    Assignee: Maxwell Laboratories, Inc., Sierra Capacitor Filter Division
    Inventors: Robert A. Stevenson, Donald N. Pruett
  • Patent number: 5328517
    Abstract: A method is provided for removing material from a structure having at least one layer of material formed on a substrate. The method includes the steps of irradiating a target area of a structure with radiant energy sufficient to break or weaken chemical bonds in the material, and impinging the target area with a particle stream to remove the pyrolyzed material from the structure. The method may be implemented by a system comprising a housing having a window; a radiant energy source mounted in the housing for irradiating the target area of the structure with the radiant energy; and a nozzle mounted to the exterior of the housing for directing the stream of particles at the target area.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: July 12, 1994
    Assignees: McDonnell Douglas Corporation, Maxwell Laboratories, Inc., Cold Jet, Inc.
    Inventors: Michael C. Cates, Richard R. Hamm, Michael W. Lewis, Wayne N. Schmitz
  • Patent number: 5281798
    Abstract: Pulsed light sources, such as a flashlamp or laser, remove coatings from substrates via the ablation method. A photodetector circuit, sensing reflected light from the surface being ablated, provides a feedback signal that indicates the reflected color intensity of the surface being ablated. The boundary between the coatings or substrate surfaces is distinguished by a change in color intensity between an upper coating and an undercoating, e.g., between a topcoat of paint and a primer coat of paint, or between a coating and the substrate surface itself. The color intensity determination thus provides a measure relative to when one coating has been removed and another coating remains. The photodetector circuit is also useful for providing feedback information relative to the quality of a stripped work surface for quality control or other purposes.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: January 25, 1994
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Richard R. Hamm, John D. Hoogerwerf
  • Patent number: 5229743
    Abstract: A protection arrangement for a high voltage tube includes a low inductance disk resistor connected in series with the anode of the tube. When an electrical discharge occurs within the tube, the increased anode current flows through the resistor which absorbs much of the potentially harmful energy surge. The resistor is a disk resistor having two counter-wound planar spirals of resistance wire electrically connected in parallel and counter-wound with respect to one another. Connection arrangements are provided to both electrically and mechanically connect the resistor to the high voltage tube.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: July 20, 1993
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Gary R. Miscikowski, Joseph M. Briscoe
  • Patent number: 5214685
    Abstract: A polished aspheric mirror focusses a fan X-ray beam from a point source onto a work piece as a straight image line. The work piece can be efficiently exposed to the X-ray beam by simply tilting the aspheric mirror about a rotational axis, causing the focused image line to sweep across the workpiece. The aspheric mirror is designed to collimate the beam in one direction, e.g., the horizontal direction, and focus the beam in the other direction, e.g., the vertical direction, thereby creating the focused image line at the workpiece. This process is achieved by representing the mirror surface as at least a fourth order Maclaurin series polynomial, and by adjusting the coefficients of such Maclaurin series to create and maintain the desired straight image line. The mirror surface is then polished using computer controlled polishing techniques to realize the designed shape.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: May 25, 1993
    Assignee: Maxwell Laboratories, Inc.
    Inventor: Malcolm R. Howells
  • Patent number: 5204517
    Abstract: A method for removing material from a structure, comprising the steps of: (1) generating a light beam; (2) irradiating the surface material of a structure with the light beam having an intensity sufficient to ablate the surface material and to cause the surface material to generate spectral emission signals having intensities; (3) scanning the structure with the light beam at a scan speed; (4) monitoring the spectral emissions to detect a selected one of the spectral emission signals having a selected wavelength and generating an electronic output signal representative of the intensity of a selected one of the spectral emission signals in response to detecting the selected one of the spectral emission signals; (5) determining an updated scan speed functionally related to the electronic output signal; and (6) directing the scan speed to be equal to the updated scan speed.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: April 20, 1993
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Michael C. Cates, Richard R. Hamm, John D. Hoogerwerf
  • Patent number: 5194723
    Abstract: The present invention provides an automated system and method for removing one or more layers of a material from a substrate. The system and method include irradiating a structure comprising at least one layer of material formed on a substrate with a light beam having an intensity sufficient to ablate the materials in order to expose selected regions of the substrate, where the ablated material generates photoacoustic signature signals; scanning the structure with the light beam along a predetermined path at a scan speed; detecting the photoacoustic signature signals; determining an updated scan speed functionally related to the detected photoacoustic signals; and directing the scan speed to be equal to the updated scan speed.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: March 16, 1993
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Michael C. Cates, Richard R. Hamm
  • Patent number: 5126638
    Abstract: A high power pseudospark switch (40) utilizes a coaxial cylindrical electrode geometry to provide a large number of pseudospark discharge channels (60) in a compact space. The coaxial cylindrical electrode geometry includes a hollow cylindrical anode (52) inside of a larger hollow cylindrical cathode (54). A plurality of radially aligned holes (57, 59) are equally spaced around the perimeter of both the hollow anode and cathode, thereby forming an annular pseudospark discharge (PSD) channel about the coaxial center axis. A plurality of such PSD channels (56, 58) are then stacked along the length of the coaxial cylindrical electrode geometry. A single trigger pulser (48) aligned with the center axis of the cylindrical electrodes provides a way for simultaneously triggering a discharge in each PSD channel.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: June 30, 1992
    Assignee: Maxwell Laboratories, Inc.
    Inventor: Rolf Dethlefsen
  • Patent number: 5126621
    Abstract: A flashlamp provides a ruggedized yet simple-to-manufacture construction capable of operating at high average output power over a long life. The flashlamp construction includes a glass tube (12) with an electrode assembly (24) detachably secured to each end. The electrode assembly includes an end cap (26) to which an electrode support (28) is attached, with a first end (32) of the electrode support protruding inside of the glass tube, and a second end (44) of the electrode support protruding outside of the glass tube. The electrode support (28) is made from a suitable electrical conductor. An electrode (34) is threaded onto the first end of the electrode support (28) without the use of brazing or other attachment techniques that might introduce impurities. An electrode lug (36) is attached to or near the second end of the electrode support, outside of the glass tube, and provides a means for making electrical contact with the electrode (34).
    Type: Grant
    Filed: January 24, 1991
    Date of Patent: June 30, 1992
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Richard G. Morton, William J. Connally
  • Patent number: 5107187
    Abstract: A protection arrangement for a high voltage tube includes a low inductance disk resistor connected in series with the anode of the tube. When an electrical discharge occurs within the tube, the increased anode current flows through the resistor which absorbs much of the potentially harmful energy surge. The resistor is a disk resistor comprising two counter-wound planar spirals of resistance wire electrically connected in parallel and counter-wound with respect to one another. Connection arrangements are provided to both electrically and mechanically connect the resistor to the high voltage tube.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: April 21, 1992
    Assignee: Maxwell Laboratories, Inc.
    Inventor: Gary R. Miscikowski
  • Patent number: 5034235
    Abstract: Methods for food product preservation by inactivation of microorganisms and/or enzymes by applying pulses of very intense, very short duration pulses of light in the visible and near visible frequencies to the surface of food products to be preserved. Also disclosed are packaging methods and apparatus utilizing such intense, short pulses of polychromatic, incoherent light.
    Type: Grant
    Filed: June 8, 1989
    Date of Patent: July 23, 1991
    Assignee: Maxwell Laboratories, Inc.
    Inventors: Joseph E. Dunn, R. Wayne Clark, John F. Asmus, Jay S. Pearlman, Keith Boyer, Francois Painchaud, Gunter A. Hofmann