Patents Represented by Attorney George F. Helfrich

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  • Bis[4-(3,4-dimethylene-pyrrolidyl)phenyl] methane
    Patent number: 4895915
    Abstract: A polyimide composition consisting essentially of recurring units having the following structural formula: ##STR1## is produced by the copolymerization of a bismaleimide and bis[4-(3,4-dimethylenepyrrolidyl)phenyl] methane.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: January 23, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Raphael M. Ottenbrite
  • Cable suspended windmill
    Patent number: 4894554
    Abstract: A windmill includes an airframe having an upwind end and a downwind end, a first rotor rotatably connected to the airframe, and a generator supported by the airframe and driven by the rotor. The airframe is supported vertically in an elevated disposition by poles which extend vertically upwardly from the ground and support cables which extend between the vertical poles. Suspension cables suspend the airframe from the support cable.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: January 16, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Moses G. Farmer
  • Method and apparatus for determining optical absorption and emission characteristics of a crystal or non-crystalline fiber
    Patent number: 4890915
    Abstract: A method of determining optical absorption and emission spectra from a crystal or non-crystalline fiber sample includes directing a laser light source to a side of the fiber sample and measuring fluorescence intensity at various positions along the crystal fiber sample, and then directing a broadband light source through the ends of the crystal fiber sample and measuring absorption in a region of no fluorescence. The preferred apparatus for carrying out the method includes a broadband light source to generate measurable absorption outside the region of fluorescence and a laser light source for generating measurable absorption in the region of fluorescence.
    Type: Grant
    Filed: August 16, 1988
    Date of Patent: January 2, 1990
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Charles E. Byvik, A. Martin Buonchristiani
  • Acetylene terminated aspartimides and resins therefrom
    Patent number: 4889912
    Abstract: Acetylene terminated aspartimides are prepared using two methods. In the first, an amino-substituted aromatic acetylene is reacted with an aromatic bismaleimide in a solvent of glacial acetic acid and/or m-c=resol. In the second method, an aromatic diamine is reacted with an ethynyl containing maleimide, such as N-(3-ethynylphenyl) maleimide, in a solvent of glacial acetic acid and/or m-cresol. In addition, acetylene terminated aspartimides are blended with various acetylene terminated oligomers and polymers to yield composite materials exhibiting improved mechanical properties.
    Type: Grant
    Filed: March 24, 1989
    Date of Patent: December 26, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, John W. Connell, Stephen J. Havens
  • Earth-to-orbit vehicle providing a reusable orbital stage
    Patent number: 4884770
    Abstract: A reusable earth-to-orbit vehicle 28 with an orbital stage 10 sized to fit into a payload bay equipped, earth-return-capable space vehicle 26 such as the United States Space Shuttle. The orbital stage 10 is equipped with a reusable rocket engine 13 capable of operation from the earth's surface to earth orbit. The orbital state 10 propels itself into earth orbit with the help of boosters 11 that separate and return to earth before orbit is reached. After delivering its payload 12, the orbital stage 10 is placed in the earth-return-capable space vehicle's payload bay 29 and returned to earth for reuse.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: December 5, 1989
    Assignee: The United States of America as represented by the National Aeronautics and Space Administration
    Inventor: James A. Martin
  • Circumferential pressure probe
    Patent number: 4873990
    Abstract: A probe for measuring circumferential pressures inside a body cavity. In the preferred embodiment, a urodynamic pressure measurement probe for evaluating human urinary sphincter function is disclosed. Along the length of the probe are disposed a multiplicity of deformable wall sensors (15) which typically comprise support tube sections (55) with flexible side wall areas (57, 16). These are arranged along the length of the probe in two areas, one just proximal to the tip (13) for the sensing of fluid pressure inside the bladder, and five in a sensing section (14) which is positioned within the urethra at the point at which the urinary sphincter constricts to control the flow of urine. The remainder of the length of the probe comprises multiple rigid support tube sections (10) interspersed with flexible support tube sections in the form of bellows (58) to provide flexibility.
    Type: Grant
    Filed: September 23, 1988
    Date of Patent: October 17, 1989
    Assignees: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration, Virginia Commonwealth University
    Inventors: Harlan K. Holmes, Thomas C. Moore, Jr., Andrew J. Fantl
  • Compression pylon
    Patent number: 4867394
    Abstract: A "compression" pylon 10 for an aircraft with a wing-mounted engine, that does not cause supersonic airflow to occur within the fuselage-wing-pylon-nacelle channel 20. The chord length of the pylon 10 is greater than the local chord length of the wing 12 to which it is attached. The maximum thickness 45 of the pylon 10 occurs at a point corresponding to the local trailing edge 32 of the wing 12. As a result, the airflow through the channel 20 never reaches supersonic velocities.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: September 19, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: James C. Patterson, Jr.
  • Tensile film clamps and mounting block for the rheovibron and autovibron viscoelastometer
    Patent number: 4864865
    Abstract: A set of film clamps and a mounting block for use in the determination of tensile modulus and damping properties of films in a manually operated or automated Rheovibron. These clamps and mounting block provide uniformity of sample gripping and alignment in the instrument. Operator dependence and data variability are greatly reduced.
    Type: Grant
    Filed: November 4, 1988
    Date of Patent: September 12, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Diane M. Stoakley, Anne K. St. Clair, Bruce D. Little
  • Passive venting technique for shallow cavities
    Patent number: 4863118
    Abstract: A device for reducing drag and store separation difficulties caused by shallow cavities on aircraft in supersonic flight consisting of a group of hollow pipes the same length as the cavity. The pipes are attached to the cavity floor so as to allow air to flow through the pipes. This device allows air to flow through the pipes opposite to the direction of flow outside the pipes. This results in reduced drag and improved store separation characteristics.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: September 5, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert L. Stallings Jr., Floyd J. Wilcox, Jr.
  • Elevated temperature aluminum alloys
    Patent number: 4861551
    Abstract: Three aluminum-lithium alloys are provided for high performance aircraft structures and engines. All three alloys contain 3 wt % copper, 2 wt % lithium, 1 wt % magnesium, and 0.2 wt % zirconium. Alloy 1 has no further alloying elements. Alloy 2 has the addition of 1 wt % iron and 1 wt % nickel. Alloy 3 has the addition of 1.6 wt % chromium to the shared alloy composition of the three alloys. The balance of the three alloys, except for incidentql impurities, is aluminum. These alloys have low densities and improved strengths at temperatures up to 260.degree. C. for long periods of time.
    Type: Grant
    Filed: July 30, 1987
    Date of Patent: August 29, 1989
    Assignee: The United States of America as represented by the Administrator, National Aeronautics and Space Administration
    Inventors: Peter Meschter, Richard J. Lederich, James E. O'Neal
  • Ethynyl terminated imidothioethers and resins therefrom
    Patent number: 4861882
    Abstract: Ethynyl terminated imidothioethers (ETIs) are prepared by the reaction of a dimercaptan, such as 4,4'-dimercaptodiphenyl ether, and an ethynyl containing maleimide, such as N-(3-ethynylphenyl)maleimide. Blends of thse ETIs and ethynyl terminated polymeric materials, such as ethynyl terminated sulfones and ethynyl terminated arylene ethers, are also prepared. These resin blends exhibit excellent processability, and the cured blends show excellent fracture toughness and solvent resistance, as well as excellent adhesive and composite properties.
    Type: Grant
    Filed: July 14, 1988
    Date of Patent: August 29, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul M. Hergenrother, John W. Connell, R. Gerald Bass
  • Electronic precipitator control
    Patent number: 4860149
    Abstract: A method and apparatus for controlling power to a preciptator 27. After each spark the power to the precipitator is reduced to zero, increased along a fast ramp 15 for a fixed period of time and then increased along a slow ramp 17 until a spark occurs. The fast and slow ramp data is computed and stored (memory 48) and then retrieved after each spark. The data retrieved is the data corresponding to the firing angle at the last spark. Apparatus is provided (selector 51 and memory 52) for dividing (frequency divider 45) the retrieved slow ramp data by a number to select the number of sparks per minute. Also the AC current and the AC voltage in the power to the precipitator are detected and the RMS values are obtained (32 and 34) and compared 35 and if the difference is above a predetermined value the power is disconnected (relay 36 and contacts 23 and 24).
    Type: Grant
    Filed: May 14, 1986
    Date of Patent: August 22, 1989
    Assignee: The United States of America as represented by the United States National Aeronautics and Space Administration
    Inventor: David F. Johnston
  • Process for making a noble metal on tin oxide catalyst
    Patent number: 4855274
    Abstract: A quantity of reagent grade tin metal or compound, chloride-free, and high-surface-area silica spheres are placed in deionized water, followed by deaerating the mixture by boiling and adding an oxidizing agent, such as nitric acid. The nitric acid oxidizes the tin to metastannic acid which coats the spheres because the acid is adsorbed on the substrate. The metastannic acid becomes tin-oxide upon drying and calcining. The tin-oxide coated silica spheres are then placed in water and boiled. A chloride-free precious metal compound in aqueous solution is than added to the mixture containing the spheres, and the precious metal compound is reduced to a precious metal by use of a suitable reducing agent such as formic acid. Very beneficial results have been obtained using the precious metal compound tetraammine platinum(II) hydroxide.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: August 8, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Billy T. Upchurch, Patricia A. Davis, Irvin M. Miller
  • Rapidly quantifying the relative distention of a human bladder
    Patent number: 4852578
    Abstract: A device and method rapidly quantifying the relative distention of the bladder of a human subject are disclosed. Ultrasonic transducer 1, which is positioned on subject 2 in proximity to bladder 16, is excited by pulser 3A under command of microprocessor 4 to launch an acoustic wave into patient 2. This wave interacts with bladder walls 12,13 and is reflected back to ultrasonic transducer 1, when it is received, amplified and processed by receiver 3B . The resulting signal is digitized by analog-to-digital converter 5 under command of microprocessor 4, and is stored in data memory 6B.
    Type: Grant
    Filed: November 10, 1987
    Date of Patent: August 1, 1989
    Assignee: The United State of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John A. Companion, Joseph S. Heyman, Beth A. Mineo, Albert R. Cavalier, Travis N. Blalock
  • Bis[4-(3,4-dimethylenepyrrolidyl)phenyl]methane
    Patent number: 4851544
    Abstract: A polyimide composition consisting essentially of recurring units having the following structural formula: ##STR1## is produced by the copolymerization of a bismaleimide and bis[4-(3,4-dimethylenepyrrolidyl)phenyl]methane.
    Type: Grant
    Filed: July 19, 1988
    Date of Patent: July 25, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Raphael M. Ottenbrite
  • Method for maintaining precise suction strip porosities
    Patent number: 4851071
    Abstract: A masking method which precisely controls porosity of a perforated titanium sheet having suction strips of a defined width includes separately taping suction strip areas and bonding land areas and then applying a coating of maskant material over the tape in the vicinity of the suction strips. Gaps formed on opposite sides of the suction strips are filled with the same maskant material and the bonding land tapes are removed after the masking material is semi-cured. The entire aerodynamic surface of the titanium sheet is covered with strips of tape and overlapping pieces of tape form seams in the vicinity of the bonding surface margins.
    Type: Grant
    Filed: July 22, 1988
    Date of Patent: July 25, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Frank H. Gallimore
  • Isotope exchange in oxide-containing catalyst
    Patent number: 4839330
    Abstract: A method of exchanging rare-isotope oxygen for common-isotope oxygen in the top several layers of an oxide-containing catalyst is disclosed. A sample of an oxide-containing catalyst is exposed to a flowing stream of reducing gas in an inert carrier gas at a temperature suitable for the removal of the reactive common-isotope oxygen atoms from the surface layer or layers of the catalyst without damaging the catalyst structure. The reduction temperature must be higher than any at which the catalyst will subsequently operate. Sufficient reducing gas is used to allow removal of all of the reactive common-isotope oxygen atoms in the top several layers of the catalyst. The catalyst is then reoxidized with the desired rare-isotope oxygen in sufficient quantity to replace all of the common-isotope oxygen that was removed.
    Type: Grant
    Filed: January 15, 1988
    Date of Patent: June 13, 1989
    Assignee: The United States of America as repesented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert V. Hess, Billy T. Upchurch, Kenneth G. Brown, Irvin M. Miller, David R. Schryer, Barry D. Sidney, George M. Wood, Ronald F. Hoyt
  • Reusable high-temperature heat pipes and heat pipe panels
    Patent number: 4838346
    Abstract: A reusable, durable heat pipe which is capable of operating at temperatures up to about 3000.degree. F. in an oxidizing environment and at temperatures above 3000.degree. F. in an inert or vacuum environment is produced by embedding a refractory metal pipe within a carbon-carbon composite structure. A reusable, durable heat pipe panel is made from an array of refractory-metal pipes spaced from each other, each refractory-metal pipe being embedded within a carbon-carbon composite structure. The reusable, durable, heat-pipe panel is employed to fabricate a hypersonic vehicle leading edge and nose cap.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: June 13, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Charles J. Camarda, Philip O. Ransone
  • Copolyimide with a combination of flexibilizing groups
    Patent number: 4837300
    Abstract: Novel copolyimides are prepared by reacting one or more aromatic dianhydrides with a meta-substituted phenylene diamine and an aromatic bridged diamine. The incorporation of meta-substituted phenylene diamine derived units and bridged aromatic diamine derived units into the linear aromatic polymer backbone results in a copolyimide of improved flexibility, processability, and melt-flow characteristics. The novel copolyimides are especially useful as thermoplastic hot-melt adhesives.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: June 6, 1989
    Assignee: The United States of America as represented by the Administration of the National Aeronautics and Space Administration
    Inventors: Terry L. St. Clair, Harold D. Burks, Donald J. Progar
  • Method for producing an atomic oxygen beam
    Patent number: 4828817
    Abstract: A method for producing an atomic oxygen beam is provided by the present invention. First, a material 10' is provided which dissociates molecular oxygen and dissolves atomic oxygen into its bulk. Next, molecular oxygen is exposed to entrance surface 11' of material 10'. Next, material 10' is heated by heater 17' to facilitate the permeation of atomic oxygen through material 10' to the UHV side 12'. UHV side 12' is interfaced with an ultra-high vacuum (UHV) environment provided by UHV pump 15'. The atomic oxygen on the UHV side 12' is excited to a non-binding state by exciter 14' thus producing the release of atomic oxygen to form an atomic oxygen beam 35'.
    Type: Grant
    Filed: October 29, 1987
    Date of Patent: May 9, 1989
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Ronald A. Outlaw