Patents Represented by Attorney M. E. Frederick
  • Patent number: 4757295
    Abstract: A pulsed transformer capable of providing up to 500 kilovolt or higher, 10 nanosecond rise time, and 1000 joule or higher pulses comprising non-conducting or insulated transformer cores each separated by conductive grading rings wherein n coaxial cables in combination with the grading rings are connected in parallel at one end and in series at their other ends. The transformer may function as either an inverting or non-inverting transformer. In a transformer with n cables, if a pulse voltage of V is applied to the input, an output voltage of nV will appear at the output. The cores function to isolate the coxial cables and permit them to be connected in series at their one end. Weight may be minimized by operating the transformer in gaseous Freon rather than transformer oil.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: July 12, 1988
    Assignee: Avco Research Laboratory, Inc.
    Inventor: Charles T. Pike
  • Patent number: 4756765
    Abstract: A method of removing material of poor thermal conductivity such as paint, grease, ceramics, and the like from a substrate by ablation without damage to the substrate by delivering to the material to be removed pulses or their equivalent of a laser beam having a wavelength at which the material to be removed is opaque and a fluence sufficient to ablate or decompose the material without damaging or adversely affecting the substrate or its surface.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: July 12, 1988
    Assignee: AVCO Research Laboratory, Inc.
    Inventor: Jaime A. Woodroffe
  • Patent number: 4755719
    Abstract: A spark gap switch is disclosed with a pumping system which utilizes flowing gas to replenish the interelectrode region between conductive pulses. The spark gap switch typically consists of a housing enclosing a gas filled chamber in which there are two end electrodes with an intervening trigger plane electrode that may be inserted at other than midplane. To initiate switch closure, a trigger pulse is applied between one end electrode and a trigger plane electrode causing the gas in the intervening gap to ionize and conduct and thereby bring on complete switch closure. To achieve proper gas flow each end electrode is configured as a truncated cone and gas is caused to flow from a multiplicity of ports spaced equidistantly around each cone base. The gas ascends the conical outer surface of each end electrode, sweeps over the crown and exhausts out through an opening in the center of each electrode.
    Type: Grant
    Filed: July 13, 1987
    Date of Patent: July 5, 1988
    Assignee: Auco Research Laboratory, Inc.
    Inventor: Rudolf Limpaecher
  • Patent number: 4714902
    Abstract: A method of providing laser controlled real-time optics and optic systems for a laser beam or beams utilizing near resonance nonlinear dispersion in a collision dominated gaseous medium. Refractive optical elements may be provided that function as spherical or curved reflectors and refractive lens or prisms for expanding or contracting a laser beam or beams as well as providing gratings for providing partial or total reflection or deflection of a laser beam. The generation of a grating in accordance with the invention permits total deflection of large cross-section and powerful laser beams by the investment of a moderate amount of power. Real-time color holographic displays may also be provided and phase front aberrations caused by a laser amplifier may also be corrected.
    Type: Grant
    Filed: June 17, 1985
    Date of Patent: December 22, 1987
    Assignee: AVCO Everett Research Laboratory, Inc.
    Inventors: Mordechai Rokni, Allen M. Flusberg
  • Patent number: 4712372
    Abstract: A redundancy monitor is presented which makes operational checks on the electronic overspeed control system used on aircraft turbine engines. The monitor is a small and lightweight device that can be permanently installed on the engine. Its function is to monitor both the speed pickups that count the revolutions per minute that the turbine shaft is turning and at the same time maintain a check on the performance of the circuitry which processes the data. The monitor includes a latching type BITE indicator which signifies redundant status of the speed pickups and a lamp which lights to indicate any failure in the output circuitry of the overspeed sensor system. A momentary-on type switch activates self test circuitry within the redundancy monitor.
    Type: Grant
    Filed: September 18, 1985
    Date of Patent: December 15, 1987
    Assignee: Avco Corporation
    Inventors: Thomas A. Dickey, George R. Bodetka
  • Patent number: 4658110
    Abstract: A laser beam is used to weld two or more overlapping layers of metal together. The beam is applied through tubular clamping elements which engage and squeeze the metal layers to be welded. By inserting an inert gas within the tubular elements, an oxygen-free weld zone may be obtained. The laser beam is deflected to create a substantially spiral-shaped weld pattern.
    Type: Grant
    Filed: May 1, 1984
    Date of Patent: April 14, 1987
    Assignee: Avco Corporation
    Inventors: Jule A. Miller, Mary Bazan, Gerard E. Bessette
  • Patent number: 4633057
    Abstract: A laser welder fault detector system, including a microphone and an associated electronic circuit operatively connected to a solenoid actuated ink jet, is provided to detect the formation of defective welds by an intermittently energized laser and to spray ink on sheets of metal being welded to mark the location of the defective welds. Defective welds are detected by acoustic signals generated during the welding process and picked up by the microphone, the amplitude of the signals, when defective welds are being formed, being relatively low compared to those generated when normal welds are being produced. The electronic components of the system compare the acoustic signals generated during the welding process with a reference signal characteristic of the formation of a normal weld.
    Type: Grant
    Filed: August 22, 1985
    Date of Patent: December 30, 1986
    Assignee: Avco Corporation
    Inventors: Craig A. Wilson, Stephen J. Curry, Kenneth Struzek, Ralph Falcigno
  • Patent number: 4631080
    Abstract: A method of an apparatus for heat processing of glass and/or glass forming material wherein cullet and/or the raw materials needed to form glass are heated while suspended in a high temperature gas stream which may comprise products of combustion. The particles heated both in and downstream of a burner, for example, together with products of combustion are accelerated out of the burner, preferably downwardly, through a nozzle and against a closely spaced impact surface in a separation chamber. Upon impact, the particles and/or molten droplets are separated from the products of combustion by adhering to the impact surface and form a continuous flowing layer which flows from the impact surface, over a flow surface and as a molten layer into a pool of molten glass product at the bottom of the separation chamber.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: December 23, 1986
    Assignee: Gas Research Institute
    Inventors: Leonard F. Westra, Jaime A. Woodroffe, David B. Stickler
  • Patent number: 4622050
    Abstract: An annular air filter is rotationally mounted within a plenum box, which in turn is securely mounted to the inlet end of a gas turbine engine. At least a portion of the annular air filter surrounds the inlet end of the engine. A motor is provided to rotationally drive the air filter relative to both the plenum box and the engine. An air pressure nozzle is disposed adjacent the inner circumferential surface of the air filter, and a vacuum nozzle is disposed adjacent the outer circumferential surface thereof. The air pressure and vacuum nozzles clean the air filter as the air filter is rotated relative thereto.
    Type: Grant
    Filed: July 22, 1985
    Date of Patent: November 11, 1986
    Assignee: Avco Corporation
    Inventor: William O'Connor
  • Patent number: 4565012
    Abstract: A flexible marking and measuring instrument which can be folded or rolled as may be desired or convenient comprising a plurality of preferably elongated, rectangular, flat, thin members parallel one with another and sequentially flexibly connected one to another whereby the marking instrument may be folded or rolled to fit in a pocket or tool chest and/or bent or flexed to follow substantially any surface such as, for example, an elongated pipe, board, inside and outside corners, or surface of substantially any configuration. The parallel members may, inter alia, be of the same or different widths, the instrument may be provided with portions that are foldable at the same or different angles, the instrument may be provided with edges defining predetermined angles, the instrument may be provided with marking holes, and/or the instrument may be provided with such indicia as may be desired including but not limited to dimensions in English and/or metric units and lines designating angles.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: January 21, 1986
    Inventors: Peter R. Bilodeau, Theodore W. Bilodeau
  • Patent number: 4518232
    Abstract: A method and apparatus for transforming an obscured beam into a uniform intensity pattern at the image plane of the apparatus are described. Apparatus for carrying out the invention comprises two on-axis optical elements which are designed for stigmatic imaging of an incoming obscured parallel laser beam. The first element, a paraboloid mirror, forms an imaginary stigmatic image of the beam at its focal point. The second element, a multi-faceted mirror, comprises identical flat facets disposed on an ellipsoid envelope. The ellipsoid conjugates the focal point of the paraboloid and the image plane. Selection of an image shape and dimension defines the shape and dimension of the facets. Each facet's contribution to the image is a full scale centered spot. The contribution of each facet add up to form a final uniform image. Slight variation of the image dimension, from facet to facet, allows a roll-off of the image and compensates for diffraction ripples by the edges of the facets.
    Type: Grant
    Filed: August 24, 1983
    Date of Patent: May 21, 1985
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Dominique M. Dagenais
  • Patent number: 4477332
    Abstract: Pulverized carbonaceous material such as coal while flowing through a reactor dispersed in a carrier gas substantially transparent to radiant energy and at atmospheric pressure is heated, typically for a few milliseconds to about K., by thermal radiation while maintained in the cooler carrier gas to selectively heat the pulverized material, while cooling the volatile products as they diffuse into the cooler carrier gas, followed by quenching where necessary. In the case of coal, the principal result of this treatment is a radical increase in the easily soluble fraction of the coal with substantially no net change in the solid ultimate or proximate characteristics and substantially no output gaseous volatile production.
    Type: Grant
    Filed: July 25, 1983
    Date of Patent: October 16, 1984
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: David B. Stickler
  • Patent number: 4476374
    Abstract: A rotary indexing device for indexing a member, such as a shaft, into operative working positions in which the shaft carries a plurality of indexing arms for selecting different working positions. Final positioning means for each indexing arm comprising a solenoid actuated, pneumatic operated pin for engaging the indexing arm and effects final adjustment of the indexing arm which is brought to approximately its proper position by a servo-motor. Means are also provided to provide positive confirmation that each step of the indexing operation has been properly completed to insure that the shaft has been rotated to and is in its proper position.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: October 9, 1984
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Joseph P. Saggese
  • Patent number: 4468279
    Abstract: A method for laser melting of silicon for the production of boules pulled from a pool of liquid ultraclean or ultrapure silicon wherein the boules are used for producing silicon wafers suitable for use in the electronics field. A laser beam, preferably P polarized, is directed at an angle of about 88 degrees to the normal to the surface of silicon disposed in conventional melting apparatus. A suitable mirror is preferably provided to capture and reflect that portion of the laser beam reflected from the surface of the pool. Use of the present invention permits continuous operation by adding solid silicon and melting it at the point of impingement of the laser beam with up to about 96% absorption of laser energy at this point, thereby permitting the provision of heat in a very controlled manner in a continuous ultraclean silicon crystal growth process.
    Type: Grant
    Filed: August 16, 1982
    Date of Patent: August 28, 1984
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Irving Itzkan
  • Patent number: 4456811
    Abstract: This invention is directed to a method of and apparatus for heat treating axisymmetric surfaces such as inner and outer surfaces on pipes, shafts, gears, valve seats and the like with a laser beam. An annular laser beam is provided and caused to impinge on a segmented generally conical mirror which focuses and/or directs the laser beam onto the desired surface of a work piece as an annular or ring-shaped beam with a predetermined width and energy profile. Relative movement about the axis of the laser beam may be provided between the work piece and the laser beam to average any intensity distributions around the laser beam. Additionally, relative movement along the axis of the laser beam may also be provided between the work piece and the laser beam in the case of shafts, pipes and the like to provide uniform and non-overlapping coverage of the surface to be treated.
    Type: Grant
    Filed: June 21, 1982
    Date of Patent: June 26, 1984
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Richard A. Hella, John V. Staal
  • Patent number: 4401726
    Abstract: Properties of the surface of low melting substrate parts including low melting, high conductivity reactive metal parts, are modified by forming an alloy casing thereon having the metal of the substrate as a first (matrix) component thereof together with a higher melting material as the second (reinforcing) component. The higher melting component is coated on the substrate, melted under laser heating, with gas shielding to avoid oxidation, and mixed with a melted portion of the substrate through convective circulation and the mixture is rapidly cooled to produce the alloy casing. Then the casing may be rescanned with the laser beam to rapidly melt and resolidify the casing with refined grain structure. Such grain refining may also be applied to uncoated substrates.
    Type: Grant
    Filed: December 21, 1981
    Date of Patent: August 30, 1983
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Daniel S. Gnanamuthu
  • Patent number: 4396580
    Abstract: In an apparatus for treatment of a process flow by beams of ionizing radiant energy, drag elements are provided for slowing flow velocity to achieve equal treatment of all portions of the process flow.
    Type: Grant
    Filed: March 18, 1981
    Date of Patent: August 2, 1983
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Richard M. Patrick, Charles C. Stewart
  • Patent number: 4328443
    Abstract: An electron beam device having a vacuum chamber in which an electron beam generator generates a directed stream of electrons. An electron beam window comprising a foil which seals the vacuum chamber is in the path of the stream of electrons and permits passage of the stream of electrons into a working region exterior of the chamber and adjacent the electron beam window. An electrode is positioned closely adjacent the foil and a second electrode is spaced from the foil to form an elongated working or, in the case of a laser, a lasing region between them. The electrodes are maintained at a high electrical potential which, along with the electron beam, molecularly excites a gaseous working medium between the electrodes. The included angle of electrons passing through and scattered by the foil is limited and the electron beam confined to a desired region by an external shield or bezel overlying the foil.
    Type: Grant
    Filed: March 11, 1980
    Date of Patent: May 4, 1982
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Oswald L. Zappa
  • Patent number: 4323925
    Abstract: An image sensor, suitable for resolving a high-resolution image, comprises an arrayed plurality of image sensor modules of moderate individual resolution. The high-resolution image is subdivided into contiguous sub-images, each of which is minified before being projected upon an image sensor module. This avoids bars of blindness between the fields of view of the image sensor modules, and also facilitates production and repair of the image sensor.
    Type: Grant
    Filed: July 7, 1980
    Date of Patent: April 6, 1982
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Gurdon R. Abell, Francis J. Cook, Peter D. Howes
  • Patent number: 4313739
    Abstract: The parent gas to be purified is passed end-to-end through a porous electrically conductive cylinder or its equivalent having a small wire electrode disposed along its longitudinal axis. A voltage is applied between the cylinder and wire sufficient to produce a corona discharge and ionize gas in the vicinity of the wire. Substantially only contaminants having an ionization potential less than that of the parent gas are or remain ionized and due to the electric field producing the corona discharge, are simultaneously caused to move toward the cylinder. Similarly, only electronegative gases become negatively charged in a negative corona and are likewise removed. A slightly lower pressure is maintained outside the cylinder effective to capture and remove the contaminant that has migrated to or adjacent the inner surface of the cylinder along with a small amount of the parent gas. Purified gas exits from the outlet of the cylinder.
    Type: Grant
    Filed: October 27, 1980
    Date of Patent: February 2, 1982
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Diarmaid H. Douglas-Hamilton