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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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Pin locking technique for flush fasteners retains a screw under dynamic conditions when self-locking or lock wiring devices are not practical. Spring pin is counter sunk through one side of the screw head into the component to form a flat surface.
Valve head moves in spiral motion away from seat. Motion is controlled by travel of pin along spiral groove in valve guide. Clearances between pin and groove permit free motion of valve, but effectively dampen vibration and chattering.
Release mechanism employing simple clevis fitting in combination with two pin-pullers achieves high reliability degree through active mechanical redundancy. Mechanism releases solar arrays. It is simple and inexpensive and performs effectively. It adapts to other release-system applications with variety of pin-puller devices.
Multiple resistance soldering device for attaching electric leads to multiple terminal block connectors uses power source with one terminal connected to working probe, and other terminal attached to connector carrying common pins for lead insertion. Mating of male and female connectors solders each lead to individual cup pin.
Disconnect device is described, which consists of stud with enlarged end held in collet locked by pins, which are held in place by piston. When squib is fired, trapped combustion products force piston to release pins.
The results of 7 months of study, tradeoffs, test design, and fabrication are presented for an effort to modify three ground stations in support of the ATS-F program. As a result of tests on the existing feed system of the Rosman No. 2 85-foot antenna and on the transportable ground station (TGS) 40-foot antenna, it was determined that modifications of the existing phase-compensating rotary joints at Rosman are feasible. Other components must be completely replaced. In the TGS antenna feed system, it was found to be feasible to broadband the existing monopulse comparator by adding simple irises and posts; both spare and active comparators were modified. The TGS polarizers can be broadbanded by adjusting existing pins and adding two new pins. These modifications are also directly applicable to the Mojave 40-foot antenna. Detailed electrical and mechanical characteristics are presented for the new equipment, as well as installation plans to enable NASA and its contractors to determine the adequacy of the designs and to confirm that planned locations are both available and compatible with planned operational concepts.
A simplified design analysis was conducted on a nutating plate type drive system for a 2500 horsepower helicopter main rotor gear box. A drive system that split the output torque evenly between two nutating plates for the purpose of reducing the load on each nutating plate was analyzed. Needle bearings were used on the nutating plate pins. The results of the analysis indicate that the required load capacity of the pin bearings and the speed of the nutating plate bearings were beyond the state-of-the-art capacity of rolling-element bearings. The analysis further indicates that the nutating plate drive is less efficient, and results in a higher weight per horsepower than a conventional planetary helicopter transmission with similar design specifications.
Fuel volume swelling and clad diametral creep strains were calculated for five fuel pins, clad with either T-111 (Ta-8W-2.4Hf) or PWC-11 (Nb-1Zr-0.1C). The fuel pins were irradiated to burnups between 2.7 and 4.6%. Clad temperatures were between 1750 and 2400 F (1228 and 1589 K). The maximum percentage difference between calculated and experimentally measured values of volumetric fuel swelling is 60%.
Two molybdenum-uranium dioxide cermet fuel pins with molybdenum clad were fission-heated in a forced-convection helium coolant for sufficient time to achieve 5.3% burnup. The cermet core contained 20 wt % of 93.2% enriched uranium dioxide. The results were as follows: there was no visible change in the appearance of the molybdenum clad during irradiation; the maximum increase in diameter of the fuel pins was 0.8%; there was no migration of uranium dioxide along grain boundaries and no evident interaction between molybdenum and uranium dioxide; and, finally, approximately 12% of the fission gas formed was released from the cermet core into the gas plenum.
The design of a MOS 256-bit Random Access Memory (RAM) is discussed. Technological achievements comprise computer simulations that accurately predict performance; aluminum-gate COS/MOS devices including a 256-bit RAM with current sensing; and a silicon-gate process that is being used in the construction of a 256-bit RAM with voltage sensing. The Si-gate process increases speed by reducing the overlap capacitance between gate and source-drain, thus reducing the crossover capacitance and allowing shorter interconnections. The design of a Si-gate RAM, which is pin-for-pin compatible with an RCA bulk silicon COS/MOS memory (type TA 5974), is discussed in full. The Integrated Circuit Tester (ICT) is limited to dc evaluation, but the diagnostics and data collecting are under computer control. The Silicon-on-Sapphire Memory Evaluator (SOS-ME, previously called SOS Memory Exerciser) measures power supply drain and performs a minimum number of tests to establish operation of the memory devices. The Macrodata MD-100 is a microprogrammable tester which has capabilities of extensive testing at speeds up to 5 MHz. Beam-lead technology was successfully integrated with SOS technology to make a simple device with beam leads. This device and the scribing are discussed.
One component serves three functions, electrical interconnections, thermal control, and mechanical integrity, at same time. Several versions of design: (1) Insulated support plate contains holes; (2) Alternate support plate configuration uses rivets instead of pins; and (3) Another configuration includes leaf-spring contacts instead of pins or rivets.
Coating compositions were evaluated for oxidation protection of directionally solidified composite alloy NiTaC-13. These coatings included three NiCrAlY compositions (30-5-1, 25-10-1 and 20-15-1), two FeCrAlY compositions (30-5-1 and 25-10-1), a CoCrAlY composition (25-10-1), and one duplex coating, Ni-35Cr + Al. Duplicate pin samples of each composition were evaluated using two cyclic furnace oxidation tests of 100 hours at 871 C and 500 hours at 1093 C. The two best coatings were Ni-20Cr-15Al-lY and Ni-35Cr + Al. The two preferred coatings were deposited on pins and were evaluated in detail in .05 Mach cyclic burner rig oxidation to 1093 C. The NiCrAlY coating was protective after 830 hours of cycling, while the duplex coating withstood 630 hours. Test bars were coated and cycled for up to 500 hours. Tensile tests indicated no effect of coatings on strength. In 871 C air stress rupture, a degradation was observed for coated relative to bare material. The cycled NiCrAlY coating offered excellent protection with properties superior to the bare cycled NiTaC-13 in 1093 C air stress rupture.
The adhesion and friction behavior of the platinum metals group was examined with clean surfaces and surfaces selectively contaminated with oxygen, vinyl chloride (C2H3Cl), and methyl mercaptan (CH3SH). A pin or disk specimen configuration was used with the pin being a single crystal of gold of the (111) orientation and with the platinum metal disks also being single crystals of the (111) or (0001) orientation. Loads applied ranged from 1 to 10 g and a sliding velocity of 0.7 mm/min was employed. Results indicate adhesion and transfer of gold to all of the platinum metals. Despite this observation friction differences existed among the metals in the group. These differences are related to surface chemical activity. Adsorption of various friction reducing species was selective. With some adsorbates present strong adhesive forces between metals were still observed.
Prelaunch oscillatory bending deflections of the Atlas/Centaur launch vehicle are restrained by a damper mechanism mounted on the end of a horizontal boom supported from the umbilical tower. A single vertical pin on the vehicle engages the mechanism, and the damper is connected to the vehicle until liftoff. As the attach pin rises with the vehicle, a retractable arm mechanism provides initial clearance. An explosive release mechanism allows the boom to swing clear of the vehicle like a pendulum, while a snubber mechanism decelerates the free swinging boom and damper mechanism to a safe stop.
A locking mechanism for orthopedic braces is described which automatically prevents or permits the relative pivotable movement between a lower brace member and an upper brace member. The upper and lower brace members are provided with drilled bores within which a slidable pin is disposed, and depending upon the inclination of the brace members with respect to a vertical plane, the slidable pin will be interposed between both brace members. The secondary or auxiliary latching device includes a spring biased, manually operable lever bar arrangement which is manually unlatched and automatically latched under the influence of the spring.
An aircraft crash location transmitter tuned to transmit on standard emergency frequencies is reported that is shock mounted in a sealed circular case atop the tail of an aircraft by means of a shear pin designed to fail under a G loading associated with a crash situation. The antenna for the transmitter is a metallic spring blade coiled like a spiral spring around the outside of the circular case. A battery within the case for powering the transmitter is kept trickle charged from the electrical system of the aircraft through a break away connector on the case. When a crash occurs, the resultant ejection of the case from the tail due to a failure of the shear pin releases the free end of the antenna which automatically uncoils. The accompanying separation of the connector effects closing of the transmitter key and results in commencement of transmission.
The device is characterized by a support column adapted to be received within an insulated, hermetically sealable chamber. A plurality of anchor pins are mounted on the column for releasibly connecting thereto a plurality of test specimens. A plurality of axially displaceable pull rods are received by the column in coaxial alignment with the anchor pins. One end of each pull rod is provided with a coupling for connecting the pull rod to a test specimen. The opposite end of the pull rod is entended through a cover plate and adapted to be connected with a remotely related linear actuator through a connecting link including a load cell for measuring stress as the pull rod is placed in tension by the actuator.
The adherence, friction, and wear properties of thin hard refractory compound coatings applied to 440C bearing steel by radiofrequency sputtering were investigated. Friction and wear tests were done with nonconforming pin on disk specimens. The compounds examined were chromium carbide, molybdenum silicide, and titanium carbide. The adherence, friction, and wear were markedly improved by the application of a bias voltage to the bearing steel substrate during coating deposition. Analysis by X-ray photoelectron spectroscopy indicated that the improvement may be due to a reduction in impurities in bias deposited coatings. A fivefold reduction in oxygen concentration in MoSi2 coating by biasing was noted. Chromium carbide was not effective as an antiwear coating. Molybdenum silicide provided some reduction in both friction and wear. Titanium carbide exhibited excellent friction and antiwear properties at light loads. Plastic flow and transfer of the coating material onto the pin specimen appears to be important in achieving low friction and wear.