Abstract: An airborne tree trimming apparatus for installation on a helicopter or the like, and operating independently of the helicopter, which apparatus includes a boom extension vertically suspended from the helicopter and a plurality of circular saw blades arranged in tandem, coplanar relationship on an operating boom which is attached to the boom extension by means of a boom pivot. The circular saw blades are designed to rotate about parallel, substantially horizontal axes which are oriented substantially at right angles to the normal direction of motion of the helicopter and are belt-driven by an internal combustion engine which is also mounted on the operating boom, above the circular saw blades. A pair of ground-located cradles not attached to the operating boom, permit the apparatus to be landed with the operating boom elevated from ground level, by maneuvering the helicopter to lay the operating boom and circular saw blades on the cradles in front of the helicopter.

Abstract: A detector (32) monitors infrared ray emissions from an air preheater (10) rotor (14) to detect a temperature rise that precedes a fire within air preheater (10) with each sensor output being processed independently by signal processing electronics. The instantaneous minus the average temperature of rotor (14) is calculated and compared to a variable trip level signal to determine whether a hot spot has been detected. The detector (32) scans across the face of rotor (14) until an initial hot spot is detected, whereupon the scanner motor (58) ceases operation thereby locating the scanner over the rotor radial position of the detected hot spot. If the same hot spot is detected on the next subsequent rotor pass, a hot spot alarm (60) is energized. If the hot spot is not detected on the next subsequent rotor pass, detector scanning is resumed by energizing scan motor (58).

Abstract: In a circuit that detects from a received RF signal the digital signal modulated on the IF carrier signal by recovering the unmodulated IF carrier signal and comparing the recovered IF carrier with the downconverted RF signal, improvements are presented which minimize errors due to rapid and large phase changes in the RF signal. The circuit includes a downconverter (104) for downconverting the received RF signal to the IF level and a phase-locked loop (115, 118, 116, 119, 117) for both providing correction for relatively slow variations in the RF signal and for deriving the recovered IF carrier signal to which the downconverted IF signal is compared (108). Large and rapid phase changes in the RF signal are detected in a separate loop in the phase locked loop by monitoring (122) the sign and phase of the phase locked loop error signal for signals exceeding a predetermined threshold and rapidly advancing (123) or retarding (124) the phase of the recovered IF carrier whenever the threshold is exceeded.

Abstract: To minimize secondary losses and flow maldistribution, an aerofoil such as a gas turbine nozzle guide vane, is designed so that in the throat defined by the trailing edge of one aerofoil and the flank of the adjacent aerofoil, the local gas flow streamlines are normal to the trailing edge of the aerofoil at the point of intersection.

Abstract: A coal-tar emulsion seal coat is applied atop, spread, and pressed into an asphalt pavement by a continuous rolling technique whereby liquid sealant is carried by and released from a delivery tank extending between the sides of a frame onto the asphalt surface. A first and second set of rollers extending between the frame sides spread and smooth an even pattern of sealant, then a third, smaller, lighter roller provides a finishing and touch-up operation.

Abstract: Apparatus of the "coil tubing injector" type which is capable of running coupled pipe into or out of a well continuously. Methods are also disclosed.

Abstract: A seat adjuster mounts a vehicle seat for back and forth adjustment between different functional positions and is adapted to lock the seat in each selected position. When the seat back is tilted forwardly, the seat adjuster releases the seat to enable the seat to move fully forwardly to an entry position. A mechanical memory is incorporated in the seat adjuster and, when the seat is shifted rearwardly following forward movement to its entry position, the mechanical memory automatically stops the seat in its last-established functional position.

Abstract: An articulated wheel chair includes front and rear sections which are pivotally connected together to permit pivoting therebetween about a vertical axis. The front section is provided with a pair of support wheels and the rear section is provided with a pair of propulsion wheels driven by an electric motor. A seat for the occupant is pivotally mounted on the rear section and is connected to the front section by a link to cause pivoting of the seat in response to articulated pivoting movement between the sections.

Abstract: A vehicle adapted for transporting and manipulating objects within a confined space, such as a tunnel. The vehicle comprises a pair of side frames interconnected by vertically adjustable front and rear interconnecting members that include horizontal portions onto which a boom is slideably and pivotally connected. Raising and lowering of one or two of the interconnecting members and lateral traversing of one or two of the connected boom portions provides for manipulation of an object or tool attached to the boom.

Abstract: An adjustment kit for adjusting the camber angle of front wheels suspended by a twin I-beam suspension system includes a cylinder having a radial flange which supports the lower end of one of the helical springs of the suspension system. A piston is positioned in the cylinder and has a radius rod bolt secured thereto and to one of the suspension beams. The relative position of the piston and cylinder may be readily changed by increasing or decreasing the amount of grease with the cylinder to thereby change the camber angle.

Abstract: A hydraulically operated slip assembly, connectible to a well head or well pipe handling machine and useful to intermittently grip pipe being run into or pulled from the well. The slip assembly has upper and lower plates with passages for pipe. Wedges, carrying unique slip systems, are positioned around the passages and slidably mounted for radial movement between guide plates extending from the upper and lower plates. The wedges are moved radially inward to grip pipe and radially outward to release pipe by a hydraulic cylinder, pivotally mounted aside the lower plate. When actuated to extend, the hydraulic cylinder rotates an inner bearing race and attached camming segments, which move the wedges inwardly to grip pipe. When the cylinder is actuated to contract, the bearing race and camming segments are rotated to pull the wedges outward radially, releasing pipe. The bearing outer race is housed in ring segments between and connecting the slip assembly upper and lower plates.

Abstract: A press having a generally "C" shaped frame, punch mounting means arranged on an upper part of the frame, and anvil support means provided on a lower part of the frame. A relatively deep throat is thereby afforded for sheet metal which may be inserted between said punch mounting means and said anvil support-means. Anvil-support suspension mounting means are provided on the upper part of the frame to allow a further anvil support to be suspended from that part of the frame, whereby smaller work can be operated on by the machine.

Abstract: In accordance with the invention humidity resistant matches having excellent and improved humidity resistance as well as excellent strike sensitivity are provided using a polyacrylic or substituted polyacrylic acid as the binder and zinc oxide as the filler, or as at least one of the components of the filler.

Abstract: A first pipe is connected to the wall of a container such as a larger pipe, tank or other vessel, wherein the transverse surface of one end of the first pipe is substantially flush with the inside surface of the portion of the wall of the container to which the first pipe is connected. The method for forming the pipe connection relies upon the plastic memory of the synthetic thermoplastic polymeric material from which the end portion of the first pipe and the portion of the wall of the container, to which the first pipe is to be connected, are formed. The diameter of a hole in the wall of the container is expanded in a cold condition in such a manner that the edges of the hole expand outwardly from the wall of the container while the diameter of the end portion of the first pipe is reduced in a cold condition such that the reduced diameter portion of the first pipe can be inserted into the expanded hole.

Abstract: Improved coil tubing injection apparatus for servicing wells by running coil tubing thereinto for circulating fluids through the well and having the ability to rotate the coil tubing for performing drilling operations. The apparatus can readily provide concurrent longitudinal and rotational movement of the coil tubing. Methods of servicing wells involving such movement of coil tubing are disclosed.

Abstract: The present invention relates to a portable transceiver and a remote terminal station each using at least two antennas with different polarization transmission capabilities for an adaptive retransmission technique. In the present adaptive retransmission technique, the terminal station transmits the same preamble signal in at least two time slots of a frame period of a time division sequence using the antenna receiving the strongest signal from the transceiver in the immediately prior frame period followed by a binary message signal using the same antenna. The transceiver receives each of the preamble transmissions from the terminal station via a separate one of differently oriented antennas and determines which antenna received the strongest signal. The message signal from the terminal station is then received via the antenna of the transceiver having received the strongest signal and also sends its response message signal on that antenna during a separate time slot of a frame period.

Abstract: The present invention relates to a linear, class A FET amplifier circuit capable of providing linear amplifier of input signals with a time-varying envelope function. An envelope detector (12) is responsive to an input signal (v.sub.i (t)) for extracting the envelope signal (V.sub.i (t)) therefrom. A gate controller (16) subsequently adds the envelope signal to a predetermined gate bias voltage (E.sub.G) and applies the sum (E.sub.G (t)) as the "d-c" gate input to the FET amplifier (14). Therefore, the gate bias voltage is dynamically controlled by the envelope of the input signal, resulting in a significant improvement in the power-added efficiency (.eta..sub.added) over prior art class A FET amplifiers.