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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Simple, inexpensive milling machine tapers panels from a common apex to a uniform height at panel edge regardless of the panel perimeter configuration. The machine consists of an adjustable angled beam upon which the milling tool moves back and forth above a rotatable table upon which the workpiece is held.
Cold machining process, which uses a sub-zero refrigerated cutting fluid, is used for machining refractory or reactive metals and alloys. Special carbide tools for turning and drilling these alloys further improve the cutting performance.
Single tool prepares a pipe end for precision welding by simultaneously performing internal machining, end facing, and bevel cutting to specification standards. The machining operation requires only one milling adjustment, can be performed quickly, and produces the high quality pipe-end configurations required to ensure precision-welded joints.
Computer program is designed for automatically programmed tools. Preprocessor computes desired tool path and postprocessor computes actual commands causing machine tool to follow specific path. It is used on a Cincinnati ATC-430 numerically controlled machine tool.
Shadowgraph system projects magnified image on screen so that alignment of small electrodes mounted on electrical discharge machines can be corrected and verified. Technique may be adapted to other machine tool equipment where physical contact cannot be made during inspection and access to tool limits conventional runout checking procedures.
A machine designed to locate automatically a star image on a photographic plate from approximate coordinates on a punched card and to measure and record its position to a micron is described. The main frame of the machine is of granite, as are the x and y coordinate carriages which move on air bearings against granite ways. The system is capable of making measurements continuously over a 10 x 10 inch range by means of a Ferranti moire fringe system, with a least count of one micron.
The design, fabrication, development, operation, calibration and results from reversed bending combined with steady torque fatigue research machines are presented. Fifteen-centimeter long, notched, SAE 4340 steel specimens are subjected to various combinations of these stresses and cycled to failure. Failure occurs when the crack in the notch passes through the specimen automatically shutting down the test machine. These cycles-to-failure data are statistically analyzed to develop a probabilistic S-N diagram. These diagrams have many uses; a rotating component design example given in the literature shows that minimum size and weight for a specified number of cycles and reliability can be calculated using these diagrams.
Survey of the present technological development status of machine intelligence for autonomous manipulation in the U.S., Japan, USSR, and England. The extent of task-performance autonomy is examined that machine intelligence gives the manipulator by eliminating the need for a human operator to close continuously the control loop, or to rewrite control programs for each different task. Surveyed research projects show that the development of some advanced automation systems for manipulator control are within the state of the art. Yet, many more realistic breadboard systems and experimental work are needed before further progress can be made in the design of advanced automation systems for manipulator control suitable for new major practical applications. Specific research areas of promise are pointed out.
Published report discusses development of two-component force dynamometer which is used for dynamic measurement of machining forces in cutting and thrust directions. Resulting data suggest that faster metal-cutting machines may be developed that have reduced vibrations.
Fully-automatic tube-joint soldering machine can be used to make leakproof joints in aluminum tubes of 3/16 to 2 in. in diameter. Machine consists of temperature-control unit, heater transformer and heater head, vibrator, and associated circuitry controls, and indicators.
Two methods of augmenting the structure of a sequential machine so that it is diagnosable are presented. The checkable (checking sequences) and repeated symbol distinguishing sequences (RDS) are discussed. It was found that as few as twice the number of outputs of the given machine is sufficient for constructing a state-output augmentation with RDS. Techniques for minimizing the number of states in resolving convergences and in resolving equivalent and nonreduced cycles are developed.
A digital controller for controlling the operation of a folding machine enables automatic folding of a desired number of sheets responsive to entry of that number into a selector. The controller includes three decade counter stages for corresponding rows of units, tens and hundreds push buttons. Each stage including a decimal-to-BCD encoder, a buffer register, and a digital or binary counter. The BCD representation of the selected count for each digit is loaded into the respective decade down counters. Pulses generated by a sensor and associated circuitry are used to decrease the count in the decade counters. When the content of the decade counter reaches either 0 or 1, a solenoid control valve is actuated which interrupts operation of the machine. A repeat switch, when actuated, prevents clearing of the buffer registers so that multiple groups of the same number of sheets can be folded without reentering the number into the selector.
The application of a vibroacoustical method for analyzing the vibration characteristics of textile machines is discussed. A drawing of a typical mechanism is provided to show the sources of vibration. The conditions under which the machine operates are defined. An accelerometer is used as a sensor. The point of installation is selected so that a dip in the frequency characteristic of the vibrating part, on which the sensor is installed, in the region of the maximum acoustical signal. This allows for a drop in the vibrations for those values of the gap in the mechanism which amount to 10 to 20 db.
A brief review of the development over the last decade of earth resource information systems is presented. Machine data preprocessing and analysis methods are surveyed and illustrated. These include preprocessing steps intended to modify geometric and radiometric aspects of earth observational image data to enhance the ability of either human interpreters or machine algorithms to extract information from the data. Illustrations of processed and analyzed images from spaceborne sensors including the Earth Resources Technology Satellite are discussed.
A substantial improvement in the performance of an 8-centimeter-diameter auxiliary propulsion thruster was achieved by reducing the diameter of the accelerator grid apertures. The accelerator grid hole geometry was defined by ion machining accelerator grids on an 8-centimeter thruster at thrust levels of 2.2, 4.4, and 6.7 millinewtons was (mN). A thruster with an ion machined accelerator grid was operated at a thrust of 4.4 mN for 1000 hours. The discharge propellant utilization was 92% at an eV/ion of 338. Thruster performance and accelerator grid hole geometry was documented as a function of thrust level. It was also determined that the small hole accelerator grid has a very low backstreaming voltage limit. In fact the thruster can be operated with the acclerator grid held at neutralizer tip potential.
Tests were conducted at 350 K (170 F) with three groups of 8.9 cm (3.5 in.) pitch diameter spur gears made of vacuum induction melted (VIM) consumable-electrode vacuum-arc melted (VAR), AISI M-50 steel and one group of vacuum-arc remelted (VAR) AISI 9310 steel. The pitting fatigue life of the standard forged and ausforged gears was approximately five times that of the VAR AISI 9310 gears and ten times that of the bending fatigue life of the standard machined VIM-VAR AISI M-50 gears run under identical conditions. There was a slight decrease in the 10-percent life of the ausforged gears from that for the standard forged gears, but the difference is not statistically significant. The standard machined gears failed primarily by gear tooth fracture while the forged and ausforged VIM-VAR AISI M-50 and the VAR AISI 9310 gears failed primarily by surface pitting fatigue. The ausforged gears had a slightly greater tendency to fail by tooth fracture than the standard forged gears.
Machine-aided analysis of ERTS-1 MSS data obtained over the Sand Hills of Nebraska indicates that reasonably accurate soils maps can be produced automatically. An interpretation of spectral class spatial distribution and statistical character allows confident assignment of familiar soil and cover type names to computer classes. Resultant computer classification maps are displayed on a television screen or printer image. Correlation between computer maps and the USDA soils map of the same area is high. Geographic distribution of classes of interest can be accentuated by automatic methods. Percentages of cover type for any classified area also can be obtained. Interpretation of machine maps yields information concerning land use, physiographic, soil, and hydrologic patterns of the region.
A substantial improvement in the performance of an 8-centimeter-diameter auxiliary propulsion thruster has been achieved by reducing the diameter of the accelerator grid apertures. The accelerator grid hole geometry has been defined by ion machining accelerator grids on an 8-centimeter thruster at thrust levels of 2.2, 4.4, and 6.7 millinewtons (mN). A thruster with an ion machined accelerator grid has been operated at a thrust of 4.4 mN for 1000 hours. The discharge propellant utilization was 92% at an eV/ion of 338. Thruster performance and accelerator grid hole geometry has been documented as a function of thrust level. It was also determined that the small hole accelerator grid has a very low backstreaming voltage limit. In fact the thruster can be operated with the accelerator grid held at neutralizer tip potential.