Patents Represented by Attorney L. D. Wofford, Jr.
  • Patent number: 4404511
    Abstract: A power factor type motor controller in which the conventional power factor constant voltage command signal is replaced during a starting interval with a graduated control voltage. The present invention adds to the three-phase system of pending application Ser. No. 199,765, filed Oct. 23, 1980, means for modifying the operation of the system for a motor start-up interval of 5 to 30 seconds. The modification is that of providing via ramp generator 174 an initial ramp-like signal which replaces a constant power factor signal supplied by potentiometer 70. The ramp-like signal is applied to terminal 40 where it is summed with an operating power factor signal from phase detectors 32, 34, and 36 to thereby obtain a control signal for ultimately controlling SCR devices 12, 14, and 16 to effect a gradual turn-on of motor 10.
    Type: Grant
    Filed: October 13, 1981
    Date of Patent: September 13, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Frank J. Nola
  • Patent number: 4400657
    Abstract: A failure detector is provided for detecting unidirectional failures in triacs, particularly as used in power factor controllers for induction motors. In a first embodiment, the triac voltage waveform is sensed and upon detection of an unbalanced signal, corresponding to failure of the triac in either the positive or negative direction, the triac is turned full on in both directions. In a second embodiment, a pair of pulsed signals are derived, the pulse durations of which are proportional to the phase difference between the load current and voltage for each half cycle, and the triac is turned full on responsive to a difference in pulse duration between the half cycle signals. An unidirectional open circuit detector is adapted to use a signal from either of the first and second embodiments to turn the triac off in response to an open circuit failure in either direction.
    Type: Grant
    Filed: November 30, 1981
    Date of Patent: August 23, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Frank J. Nola
  • Patent number: 4398412
    Abstract: A hand held device (12) having a forward open window portion (14) adapted to be pushed downwardly into the frost on a surface, and a rear container portion (22) adapted to receive the frost removed from the window area. A graph (FIG. 4) on a side of the container enables an observer to determine the density of the frost from certain measurements noted. The depth of the frost is noted from calibrated lines (28) on the sides of the open window portion (14).
    Type: Grant
    Filed: March 18, 1982
    Date of Patent: August 16, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Farouk Huneidi
  • Patent number: 4394610
    Abstract: A control system for a permanent-magnet motor (10) driven by a multiphase line-commutated inverter (12) is provided with integrators (24) for integrating the back EMF of each phase of the motor for use in generating system control signals for an inverter gate logic (30) using a sync and firing angle (.alpha.) control generator (26) connected to the outputs of the integrators. A precision full-wave rectifier (16) provides a speed control feedback signal to a phase-delay rectifier (14) via a gain and loop compensation circuit (20) and to the integrators for adaptive control of the attenuation of low frequencies by the integrators as a function of motor speed, whereby as the motor speed increases, the attenuation of low frequency components by the integrators is increased to offset the gain of the integrators to spurious low frequencies. The .alpha.-control signals are produced by the firing angle control generator by means (48, 50) for combining 120.degree.
    Type: Grant
    Filed: August 7, 1981
    Date of Patent: July 19, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Carlisle R. Dolland
  • Patent number: 4391423
    Abstract: A satellite retrieval system (10) wherein first and second pairs of coacting parallel bars (40), and (94) are separately mounted in spaced parallel planes on the front of a spacecraft (14). The bars of one pair are at right angles to bars of the other pair, and together the two pairs of bars effect a variable aperture adapted to close around a rod (26) extending from a second spacecraft (22) to thereby effect the capture of the latter.
    Type: Grant
    Filed: March 30, 1981
    Date of Patent: July 5, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Edwin C. Pruett, Kem B. Robertson, Tomas E. Loughead
  • Patent number: 4391518
    Abstract: A dual laser optical system and method is disclosed for visualization of phenomena in transparent substances which induce refractive index gradients such as fluid flow and pressure and temperature gradients in fluids and gases. According to the invention two images 68 and 70 representing mutually perpendicular components of refractive index gradients may be viewed simultaneously on screen 66. Two lasers 10 and 12 having wave lengths in the visible range but separated by about 1000 angstroms are utilized to provide beams 14 and 20 which are collimated into a beam 32 containing components of the different wave lengths. The collimated beam 32 is passed through a test volume 33 of the transparent substance. The collimated beam is then separated into components of the different wave lengths and focused on to a pair of knife edges arranged mutually perpendicular to produce and project images 68 and 70 onto screen 66.
    Type: Grant
    Filed: January 12, 1981
    Date of Patent: July 5, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert B. Owen, William K. Witherow
  • Patent number: 4389904
    Abstract: A method and apparatus for preparing and studying samples of materials supercooled and solidified in a containerless, low-gravity environment in bulk form is disclosed which includes an enclosure 10 in which a containerless environment is provided in which a sample specimen 52 is positioned. Method contemplates heating the specimen 52 in the containerless environment, dropping the specimen melt through the tube 12 wherein it cools by radiation, and alternately backfilling the tube 12 with an inert gas whereby the specimen melt cools by both radiation and convection during its free fall. During the free fall, the sample is in a containerless, low-gravity environment which will enhance supercooling in the sample and prevent sedimentation and thermal convection influences. The sample will continue to supercool until nucleation occurs which is detected by silicon photovoltaic detectors. The sample will solidify after nucleation and be completely solid before entering the detachable catcher.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: June 28, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Lewis L. Lacy, Michael B. Robinson, Thomas J. Rathz, Lester Katz, Daniel B. Nisen
  • Patent number: 4388585
    Abstract: A power generating system for adjustably coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac. The triac is regulated to normally turn "on" at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.
    Type: Grant
    Filed: March 16, 1981
    Date of Patent: June 14, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Frank J. Nola
  • Patent number: 4381583
    Abstract: Connector apparatus and assembly is disclosed for connecting beams and the like structural members which is particularly advantageous for connecting two members together when moved laterally into place since the connector apparatus requires no relative longitudinal movement between the ends of the beams or members being connected to make a connection joint. The connector apparatus includes a receptacle member A and a connector housing B carried by opposed ends of the structural member being connected wherein a spring-loaded connector member C is carried by the connector housing B which may be released for extension and engagement into the receptacle member A.
    Type: Grant
    Filed: October 8, 1980
    Date of Patent: May 3, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Georg F. von Tiesenhausen
  • Patent number: 4362361
    Abstract: An optical manifold transforms a collimated beam, such as a laser beam, into a plurality of parallel beams having uniform intensity or having a desired intensity ratio. The manifold (10) comprises an optical substrate (12) coated on its rear surface (13) with a fully reflective layer (14) and on its front surface (15) with a partially reflecting layer (20) having a reflectivity gradient. An input collimated beam (30) entering the rear surface (13) and impinging on the front surface (14) will be reflected, multiple (32-40) between the front and rear surfaces producing a plurality of parallel beams (42, 44, 46, 48) that emerge from the front surface. The intensities of the emerging beams will have a relationship that depends on the reflectivity (R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5) of the front surface at the points where the beams emerge. By properly selecting the reflectivity gradient, the emerging beams will have uniform intensity or a desired intensity ratio.
    Type: Grant
    Filed: September 15, 1980
    Date of Patent: December 7, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Cecil W. Campbell, Robert B. Owen
  • Patent number: 4351022
    Abstract: Control signals for phase-delay rectifiers, which require a variable firing angle that ranges from 0.degree. to 180.degree., are derived from line-to-line 3-phase signals (.phi.A, .phi.B, .phi.C) and both positive and negative firing angle control signals (+.alpha. and -.alpha.) which are generated by comparing (at 20) current command and actual current (sensed at 16). Line-to-line phases are transformed (32) into line-to-neutral phases and integrated (at 34) to produce 90.degree. phase delayed signals (A.phi., B.phi., and C.phi.) that are inverted (at 26a, b, c) to produce three cosine signals (C, A and B RAMP) such that for each its maximum occurs at the intersection of positive half cycles of the other two phases which are inputs to other inverters. At the same time, both positive and negative (inverted) phase sync signals are generated for each phase by comparing (at 27a, b, c) each with the next and producing a squarewave when it is greater.
    Type: Grant
    Filed: June 30, 1981
    Date of Patent: September 21, 1982
    Inventors: Alan M. Administrator of the National Aeronautics and space Administration, with respect to an invention of Lovelace, Carlisle R. Dolland, Daniel W. Trimble
  • Patent number: 4343584
    Abstract: Apparatus for transferring and manipulating a plurality of containers in a sequence is disclosed including a mechanical manipulator arm 10 having a gripping device B which automatically picks up a container at a fixed pickup position P and transfers it to a processing station.At a processing station X, the container is loaded with silicon wafers and thereafter returned by the arm to the fixed position P at the pickup and return station Y. A plurality of the containers may be processed in sequence from the fixed pickup position by providing a movable carriage 58 upon which container pedestal platforms 54 and 56 are supported, at least one of which is an elevator platform. The platforms include abutments 54c and 56c for properly positioning the containers for accurate pickup by the manipulator arm.
    Type: Grant
    Filed: July 11, 1980
    Date of Patent: August 10, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Jerry L. Hudgins
  • Patent number: 4319133
    Abstract: A photoelectric beam system for the detection of the arrival of an object at a discrete station wherein artificial light, natural light, or no light may be present. A signal generator turns on and off a signal light at a selected frequency. When the object in question arrives on station, ambient light is blocked by the object, and the light from the signal light is reflected onto a photoelectric sensor which has a delayed electrical output but is of the frequency of the signal light. Outputs from both the signal source and the photoelectric sensor are fed to inputs of an exclusively OR detector which provides as an output the difference between them. The difference signal is a small width pulse occurring at the frequency of the signal source. By filter means, this signal is distinguished from those responsive to sunlight, darkness, or 120 Hz artificial light. In this fashion, the presence of an object is positively established.
    Type: Grant
    Filed: April 30, 1980
    Date of Patent: March 9, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: James R. Currie, Raymond R. Schansman
  • Patent number: 4309146
    Abstract: The invention relates to the utilization of wind energy and increasing the effects thereof for power generation. Amplified wind turbine apparatus is disclosed wherein ambient inlet air is prerotated in a first air rotation chamber (B) having a high pressure profile increasing the turbulence and Reynolds number thereof and a second rotation chamber (C) adjacent and downstream of the turbine has a low pressure core profile whereby flow across the turbine is accelerated and thereafter exits the turbine apparatus through a draft anti-interference device (D) which eliminates interference with ambient winds at the outlet of the turbine apparatus. Pivotable vanes 12 controlled in response to prevailing wind direction admit air to the chambers and aid in imparting rotation. A central core 20 may be utilized for creating the desired pressure profile in chamber B.
    Type: Grant
    Filed: March 12, 1980
    Date of Patent: January 5, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Leopold A. Hein, William N. Myers
  • Patent number: 4304219
    Abstract: A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal.
    Type: Grant
    Filed: November 29, 1979
    Date of Patent: December 8, 1981
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: James R. Currie
  • Patent number: 4286542
    Abstract: Apparatus is disclosed for immersing minute integrated circuit chips in an etching solution in manufacturing integrated circuits during research and development. The apparatus includes holder member C having a handle 24 and basket support 26 for carrying a removable unitary basket A and lid structure B wherein fluid flow-through passages 20 are formed and wherein graduated openings 28 in the handle provide for adjustably supporting the basket in a beaker at a desired level.
    Type: Grant
    Filed: July 18, 1980
    Date of Patent: September 1, 1981
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Jewell G. Belcher, Jr., Ben R. Hollis, Jr.
  • Patent number: 4282752
    Abstract: A multi-channel temperature measurement amplification system wherein a plurality of differential outputs of thermocouples are sequentially amplified by a common amplifier, the amplified outputs compared with a reference temperature signal in an offset correction amplifier, and a particularly poled output signal provided when a differential output is of a discrete level compared with a reference temperature signal.
    Type: Grant
    Filed: November 29, 1979
    Date of Patent: August 11, 1981
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: James R. Currie
  • Patent number: 4262195
    Abstract: A solar tracker for a solar collector which is angularly oriented by a motor wherein the outputs of two side-by-side photodetectors are discriminated as to three ranges, a first corresponding to a low light or darkness condition; a second corresponding to light intensity lying in an intermediate range; and a third corresponding to light above an intermediate range, direct sunlight. The first output drives the motor to a selected maximum easterly angular position; the second enables the motor to be driven westerly at the earth rotational rate; and the third output, the separate outputs of the two photodetectors, differentially controls the direction of rotation of the motor to effect actual tracking of the sun.
    Type: Grant
    Filed: July 25, 1979
    Date of Patent: April 14, 1981
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Paul R. White, Donald R. Scott
  • Patent number: 4256093
    Abstract: A pump/valve unit for controlling the inflation and deflation of a urethral collar in a prosthetic urinary sphincter device is disclosed including a compressible bulb pump defining a reservoir made integral with a valve unit for implant wherein the valve unit includes a movable valve member operable by depression of a flexible portion of the valve unit housing for controlling fluid flow between the reservoir and collar and a pressure sensing means which operates the valve member to relieve an excess pressure in the collar should too much pressure be applied by the patient.
    Type: Grant
    Filed: October 12, 1978
    Date of Patent: March 17, 1981
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Curtis R. Helms, Harold M. Smyly
  • Patent number: 4247434
    Abstract: Monodisperse latexes having a particle size in the range of 2 to 40 microns are prepared by seeded emulsion polymerization in microgravity. A reaction mixture containing smaller monodisperse latex seed particles, predetermined amounts of monomer, emulsifier, initiator, inhibitor and water is placed in a microgravity environment, and polymerization is initiated by heating. The reaction is allowed to continue until the seed particles grow to a predetermined size, and the resulting enlarged particles are then recovered. A plurality of particle-growing steps can be used to reach larger sizes within the stated range, with enlarged particles from the previous steps being used as seed particles for the succeeding steps. Microgravity enables preparation of particles in the stated size range by avoiding gravity-related problems of creaming and settling, and flocculation induced by mechanical shear that have precluded their preparation in a normal gravity environment.
    Type: Grant
    Filed: December 29, 1978
    Date of Patent: January 27, 1981
    Inventors: Alan M. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Lovelace, John W. Vanderhoff, Fortunato J. Micale, Mohamed S. El-Aasser, Dale M. Kornfeld