Abstract: A method and apparatus for detecting a defect in a workpiece are disclosed. The workpiece is positioned with a surface of the workpiece to be inspected in an optical path of an infrared radiation detector. A selected portion of the workpiece is heated by scanning with electromagnetic radiation for a selected duration to cause an increase in radiance from any defect present in the selected portion. Any defects, present in the workpiece selected portion, which may cause a failure of the workpiece, may be detected and distinguished from minor surface anomalies by analyzing a transient response of the irradiance received by the infrared radiation detector.

Abstract: A method and apparatus for inspecting a channel through a workpiece or cooling holes through the surface of a gas turbine engine are disclosed. The gas turbine engine blade is mounted in a fixture such that a heated gas may be forced into the hollow interior of the blade during a heat-up cycle, and after a predetermined period of time, a solenoid valve switches to shut off the heated gas and to permit a chilled gas to be forced into the hollow interior of the blade for a cool-down cycle. An imaging infrared radiometer generates a series of images of the blade during both the heat-up and cool-down cycles. A selected group of parameters are determined from the series of images generated by the IR radiometer and defects within the cooling holes may then be detected by analyzing the parameters, such as a transient response of the infrared signature of the cooling holes during both the heat-up and the cool-down cycles.

Abstract: A non-contacting system for measuring the radius of a curved surface. The system includes a light source for illuminating the surface along the intersection of the surface with a plane which includes the radius to be measured. A lens, arranged such that its principal axis is perpendicular to the plane which includes the radius to be measured, is utilized to project a distortion free image of the intersection onto the photosensitive array within a video camera. The video signal generated by the camera is provided to a microcomputer which calculates surface radius from the image data included in the video signal.

Abstract: To prevent overheating of the gaps between shroud segments circumferentially arranged about a high pressure turbine rotor, an improved seal is provided to block radial leakage flow of hot working gas through the gaps, as well as to restrict axial flow of working gas in the gaps. The seal includes a corrugated, axial fluid flow restricting element sandwiched between a pair of radially spaced, gap spanning shim sealing elements. Pressurized cooling air is admitted to the gap at locations between the shim sealing elements via passages through adjacent shroud segments to cool the gap and to further restrict working gas axial flow in the gap.

Abstract: A method for making an engine component with a hollow interior includes the steps of: selectively patterning a principal substrate surface; forming a slurry including a selected amount of a binder material, a selected amount of a solvent and a selected amount of a filter material; inserting the slurry into the substrate surface pattern; evaporating the solvent to solidify the slurry; depositing a close-out layer of material over the patterned substrate surface and over the solidifed slurry; and without removing the close-out layer, removing the solidified slurry to provide a structure with a hollow interior.

Abstract: A squeeze film damper having spaced opposite piston rings for damper fluid sealing includes a fluid plenum groove adjacent and inboard of each ring to serve as a lower pressure receiver for damper fluid and as a reservoir to receive and supply fluid during pumping action of the damper.

Abstract: The present invention provides a device for transferring replacement fluid from a first to a second fluid system and for transferring overflow fluid from the second fluid system to the first fluid system. Replacement and overflow fluid is transferred between systems by first and second flow paths respectively, each flow path including a filter to prevent particle contamination between the systems.

Abstract: A method and apparatus for increasing response to low intensity radiation in a radiation detector includes a housing surrounding a chamber, a window adjoining the chamber, and a slot formed in one side of the chamber for admitting a circuit board into the chamber. The board supports an array of elongated detector elements on a surface thereof, an electrically conductive plate within the chamber and substantially parallel with the array of detector elements, sealant means in the slot surrounding the circuit board for providing a gas impervious seal, an ionizable gas contained in the chamber under high pressure, and a collimator mounted in a collimator support and positioned outside the chamber for directing ionizing radiation through the window for detection.

Abstract: A system for detecting energy leakage from an optical fiber transmitting high power laser beams. A second optical fiber is placed together with the laser power transmitting fiber into a jacketing tube or conduit. The second fiber is connected at one end to a light source and at the other end to a photosensitive diode. Leakage of laser energy from the power transmitting fiber will cause a failure of the second optical fiber, reducing or terminating the transmission of light to the photosensitive diode. Energy leakage from the laser power transmitting fiber can therefore be detected by monitoring the output of the photosensitive diode.

Abstract: A vision system for automating a machine process. The system includes a conventional CCD camera and a vision processor which automatically determines process parameters from a workpiece surface by generating an image of the workpiece surface, transducing the workpiece image into electrical signals, and electronically determining the process parameters from the electrical signals. Applied to a laser welding process, the vision system locates workpiece edges, determines part centerline and thickness, and calculates process parameters such as weld location, the rate of delivery of weld powder, laser intensity, and the speed at which the weld is applied.

Abstract: An edge contouring system for removing burrs from edges of precision parts. The system includes an industrial robot for moving a special piloted deburring tool along the part edges. A compliance device applies a constant force on the deburring tool to keep it in contact with the part edge, yet permits movement of the tool in a direction normal to the part surface to accommodate for irregularities in the part geometry. A pilot integral with the deburring tool limits penetration of the tool into the part edge.

Abstract: A vision system for automating a machine process. The system includes a conventional CCD camera and a vision processor which automatically determines process parameters from a workpiece surface by generating an image of the workpiece surface, transducing the workpiece image into electrical signals, and electronically determining the process parameters from the electrical signals. Applied to a laser welding process, the vision system locates workpiece edges, determines part centerline and thickness, and calculates process parameters such as weld location, the rate of delivery of weld powder, laser intensity, and the speed at which the weld is applied.

Abstract: A diameter gauge is disclosed for measuring the outside diameter of a part having a circular cross-section. The gauge comprises two arms converging to form a channel, a light source and a light detecting device. The part to be measured is placed within the channel, partially blocking or reflecting the transmission of light from the light source. The diameter of the part is determined from the location of the part shadow or reflected light.

Abstract: An improved, more energy efficient reactor-type ballasting circuit for fluorescent lamps includes an inductive ballasting coil for directly applying an AC line voltage to the cathodes of a lamp without an intermediate autotransformer and also includes a glow type thermal switch in series with a positive temperature coefficient (PTC) resistor for electrical connection across the cathodes of the lamp to conduct pre-heating current to the lamp cathodes. The PTC resistor will effectively remove the glow switch from the ballast circuit if the switch fails to open after an appropriate time delay.