Abstract: An improved bolt carrier for a firearm is provided that improves the overall reliability and performance of the firearm bolt assembly. The bolt carrier includes a bolt with a body having a number of lugs extending therefrom. The bolt includes an extractor recess sized and configured to avoid any undercut of the lugs adjacent the recess. The bolt also includes an extractor pivotably engaged in a recess formed in the bolt. The extractor has a pair nipples on flanges configured to engage a pair of integrally buffered springs disposed on a tapered spring well on either side of a firing pin bore extending through the bolt.

Abstract: An electrical gardening tool includes a working piece having a main body, and a seat body with a base seat. The main body includes a coupling strip with actuating and hook ends and a projection that is disposed within the main body, and a side wall with a slot. The base seat has a coupling end surface that is formed with a fixed bar to engage the hook end so as to fix the seat body to the working piece. The actuating end of the coupling strip is rotatable forcibly relative to the main body to turn the projection out of the main body through the slot so as to remove the hook end from the bar, thereby permitting removal of the seat body from the working piece.

Abstract: Combustion turbine power plants and methods of operating the same are provided in which air is cooled using solar energy and supplied to an air inlet of the power plant to support combustion. Also, combustion turbine power plants and methods of operating the same are provided in which steam is produced using solar energy and injected into a turbine of the power plant.

Abstract: Apparatus and methods for including a code having at least one code frequency component in an audio signal are provided. The abilities of various frequency components in the audio signal to mask the code frequency component to human hearing are evaluated and based on these evaluations an amplitude is assigned to the code frequency component. Methods and apparatus for detecting a code in an encoded audio signal are also provided. A code frequency component in the encoded audio signal is detected based on an expected code amplitude or on a noise amplitude within a range of audio frequencies including the frequency of the code component.

Abstract: A method and apparatus for automatically identifying a program broadcast by a radio station or by a television channel, or recorded on a medium, by adding an inaudible encoded message to the sound signal of the program, the message identifying the broadcasting channel or station, the program, and/or the exact date. In one embodiment the sound signal is transmitted via an analog-to-digital converter to a data processor enabling frequency components to be split up, enabling the energy in some of the frequency components to be altered in a predetermined manner to form an encoded identification message, and with the output from the data processor being connected via a digital-to-analog converter to an audio output for broadcasting or recording the sound signal. In another embodiment, an analog bandpass filter is employed to separate a band of frequencies from the sound signal so that energy in the separated band may be thus altered to encode the sound signal.

Abstract: This invention relates to electron emitting semiconductor materials for use in dynodes, dynode devices incorporating such materials, and methods of making the dynode devices. In particular, the invention relates to emissive materials having an electron affinity that is negative and which have low resistivity. The invention also relates to electronic devices such as electron multipliers, ion detectors, and photomultiplier tubes incorporating the dynodes comprising the materials, and to methods for fabricating the electronic devices. The secondary electron emitters of the present invention comprise wide bandgap semiconductor films selected from diamond, AlN, BN, Ga.sub.1-y Al.sub.y N where 0.ltoreq.y.ltoreq.1 and (AlN).sub.x (SiC).sub.1-x where 0.2.ltoreq.x.ltoreq.1. The films are preferably single crystal or polycrystalline. The films may be continuous or patterned.

Abstract: An apparatus and method for switching video signals from input lines to output lines. A control device selectively sets a blackout start time and a blackout stop time. A first comparator compares the blackout start time with actual time and a second comparator compares the blackout stop time with actual time. A switch is provided for connecting the input lines to output lines and for disconnecting the input lines from the output lines. The switch is responsive to the first comparator to disconnect all input lines from all output lines when the actual time equals the blackout start time. The switch is also responsive to the second comparator to reconnect the input lines to the output lines when the actual time equals the blackout stop time.

Abstract: Methods and apparatus for effecting a fluid-tight seal between a surface of an oil and/or gas well tubing or casing and a wellhead member are provided, wherein the surface has been unprepared to form the seal. The wellhead member is positioned circumferentially about a stub of the tubing or casing. A metal-to-metal fluid-tight sealing means of the wellhead member is positioned adjacent the unprepared surface of the tubing or casing. The sealing means has at least one metallic projection positioned to extend toward the unprepared surface of the tubing or casing. The metallic projection is forced into the unprepared surface of the tubing or casing thus to form a seal therebetween.

Abstract: A communication joint for use in a well is disclosed. The communication joint includes a one-piece tubular body having an exterior surface adapted to form a slidable fluid seal with a wellhead member of the well. The tubular body includes first and second fluid conduits extending axially along and positioned in the tubular body, each conduit providing a fluid passageway independent of the other fluid conduit. Preferably, the first and second fluid conduits extend axially above and below the exterior surface of the body.

Abstract: An improved downhole pressure measuring apparatus includes a flow tube conveying pressurized fluid from a fluid source on the surface into a borehole. The fluid flow and pressure is measured at the surface and the downhole pressure is determined.A perforating gun firing mechanism may be attached to a lower end of the flow tube and positioned in the borehole respective to a perforating gun for the firing thereof. The gun is fired by manipulating the flow tubing and the downhole pressure is simultaneously recorded.

Abstract: A differential pressure actuated vent assembly is connected into an oil well tool string. In one form of the invention, the tool string includes a packer device, a perforating gun attached to the lower end of the tubing string, with the vent assembly being interposed between the gun and the packer device. Fluid pressure within the tubing string is effected on one face of a piston associated with the vent assembly, which reciprocates the piston and communicates the interior of the tubing string with the annulus around the tubing string while carrying out the step of perforating the formation. Movement of the piston and the subsequent detonation of the gun preferably are both accomplished sequentially in response to the dropping of a bar down through the tool string. The bar opens a passageway leading to the piston, and immediately thereafter, before the pressure differential between the interior of the tubing string and the annulus is equalized, the gun is detonated, thereby obviating damage to the formation.

Abstract: A well apparatus connected to a pipe string extending down into a cased borehole for treating a formation comprising a packer assembly for sealing with the casing assembly and an integral crossover/release assembly attached to the packer assembly for supporting and releasing a gravel screen assembly before or after treating the formation without rotating the pipe string. The crossover/release assembly includes crossover ports providing a downward flow path for the treating fluid, annular veins providing an upward flow path for the returns, and a reciprocating piston reciprocating upon effecting hydraulic pressure on the piston for releasing the gravel screen assembly.

Abstract: A system and method for selectively removing a recording means from a strip chart scale to avoid marking undesired data thereon.

Abstract: An apparatus used for measuring the pressure within a body cavity and methods of manufacturing and using same. An elongated catheter has its perforated body end disposed in a guide tube used for introducing the catheter. Both the catheter and guide tube are prefilled with sterile liquid and sealed against loss thereof and disposition of the guide tube and catheter. The gauge end of the guide tube is releasably sealed and secured by a tubular member fitted frictionally over the gauge end of the guide tube and catheter.

Abstract: Apparatus for use in measuring continuously the change in pH values of a fetus, comprises a holder made of an insulating material, a spiral electrode extending from the forward end of said holder and adapted to engage the fetus during delivery, a maternal electrode supported on said holder rearward of said spiral electrode, said electrodes including a material which forms a half cell in the presence of hydrogen ions, and means responsive to the potential difference across said first and second electrodes for continuously measuring the changes in pH of the fetus.

Abstract: An improved electrode structure for use in monitoring fetal heartbeat and the like. A guide tube has an open forward end adapted to be inserted through the vagina and cervix of a woman in labor. A signal acquisition device, adapted to rotatably engage a fetal epidermis, is slidably and rotatably disposed in the guide tube. A driving member is slidably and rotatably disposed in the guide tube for driving the signal acquisition device into engagement with a fetal epidermis. A line is attached to the driving member and is wrapped circumferentially around at least a portion of the driving member. A device is affixed to the line for pulling it tangentially with respect to the drive member, whereby the driving member and the signal acquisition device may be rotated for engaging a fetal epidermis.

Abstract: A support board for use in securing the extremities of an infant against motion and method of assembling same. A rigid support member is provided. A pad of flexible material is shaped to back the support member and form a plurality of flexible straps for holding the support board to the extremity. In a preferred method of assembling the support board, the pad is affixed to the support member by folding a central member of the pad over two sides of the support member and affixing the support member between the folds of the central member.