Abstract: A heat exchanger is disclosed for heating air entering a combustion gas turbine to increase the power output of the turbine when the turbine operates in a cold environment. The heat exchanger may be used also as a cooler to cool air entering the turbine to increase the power output of the turbine when the turbine operates in a hot environment.

Abstract: A wheelchair lift apparatus for transporting a wheelchair and its occupant into and from a commercial vehicle can be installed in the existing doorway of the vehicle on a rotation column which is capable of supporting a telescoping platform assembly for movement into and out of an operative position across the doorway, there being a retention strap to prevent accidental forward rolling movement of the wheelchair as it is lifted or lowered, and a barrier plate across the front end of the forwardmost platform section cooperates with side flanges or rails on the platform section to prevent accidental movement of the wheelchair off of the platform assembly. The platform support unit is capable of lifting and lowering substantial loads without binding, and the platform assembly is hinged to the platform support unit in such a way as to require positive manual pressure in folding and unfolding the platform assembly with respect to the support unit.

Abstract: A fluid control circuit and method of operating equipment such as a blowout preventer having a two-way hydraulic piston and cylinder assembly. The circuit includes various features such as a dual pressure level independently controlled fluid supply, a dedicated secondary fluid supply reserved for supplemental use, a dedicated fluid supply reserved for exclusive use in one operating branch, automatic sensor for applying a reserve fluid supply on a sensed demand, a pressure intensifier for increasing available operating force, and control circuitry for preventing loss of enhanced secondary operating energy into a primary circuit.

Abstract: A heat exchanger is disclosed for heating air entering a combustion gas turbine to increase the power output of the turbine when the turbine operates in a cold environment. The heat exchanger may be used also as a cooler to cool air entering the turbine to increase the power output of the turbine when the turbine operates in a hot environment.

Abstract: A steering system for a tow tractor having steerable front and rear road wheels is disclosed. The steering system comprises a steering wheel for turning the front road wheels and a hydrauclic servo valve for turning the rear road wheels through an angle proportional to the turning of the front road wheels.A rear mechanical push-pull cable is used for signaling a feedback angular quantity of the turning of the rear road wheels to the servo valve. A front mechanical push-pull cable is used for signaling an input angular quantity of the turning of the front road wheels to the servo valve. A hydraulic clutch is used for remotely engaging and disengaging the front mechanical system having at least two steering modes for the front and rear road wheels.A method of operating a vehicle having mechanical controls for steerable front and rear road wheels is disclosed that eliminates the dangers of a failure mode inherent in an electronic control over hydraulic four-wheel steering device.

Abstract: A hydraulic control circuit and method of operating a blowout preventer having a two-way hydraulic piston and cylinder assembly including an open and close port. An adjustable hydraulic supply is connected to a control valve which is in turn connected to the open and close ports. A pressure booster having an input and an output is connected to the close port and a control circuit is connected to the input of the booster and to the close port for actuating the booster and also blocking flow from the control valve to the closed port when the hydraulic supply increases to a predetermined value.

Abstract: A rigid water conduit is manifold connected to a rotary swivel connection and receives high pressure water therefrom and supplies the water to a plurality of jet nozzles. The jet nozzles are rotated about an axis offset from the nozzles and reciprocating means are connected to the manifold for reciprocating the manifold and nozzles about the swivel connection. The swivel connection includes a housing with a water inlet adapted to be connected to a water pump with a hollow mandrel rotatable in the housing and connected to the manifold and having an opening in communication with the water inlet. A bearing and a seal are provided between the mandrel and the housing on each side of the opening whereby the mandrel may be easily rotated. A track is positioned generally transverse to the manifold and a carriage movable on the track includes a pivoting support having bearings for supporting the mandrel but allowing movement of the mandrel transverse to the carriage.

Abstract: Improving the operation of a diesel engine at light loads in which the engine includes a plurality of cylinders, a piston in each cylinder, a fuel injector for each cylinder, an air blower for supplying air to the cylinders and an exhaust manifold. A valve is pivotally positioned in the exhaust manifold, and biasing means is connected to the valve acting to bias the valve towards a closed position. The modulating valve restricts the flow from the manifold at light loads thereby maintaining a back pressure on the exhaust at lighter loads for improving engine performance, but opens wider by exhaust flow from the manifold at higher loads. An adjustable stop may be positioned in the path of travel of the valve preventing the valve from entirely closing. The valve may be a butterfly valve pivotally supported off-center and the biasing means may include a weight connected to a lever arm connected to the pivot supporting the valve. Improved fuel injectors provide less fuel than normal injectors at lighter loads.

Abstract: A hydraulic control system for controlling a plurality of remotely positioned hydraulically actuated underwater devices by a single hydraulic control line extending underwater. A reference hydraulic manifold is connected to the single control line and a signal hydraulic manifold is connected to the single control line. A pilot actuated hydraulic control valve is connected to each of the underwater devices controlling the flow of actuating fluid thereto. The pilot of each valve is connected to both the reference manifold and the signal manifold, but the pilot of each of the valves is actuated by different pressure levels in the signal manifold whereby the underwater devices may be controlled in a predetermined sequence by applying predetermined pressure levels to the single hydraulic control line. A pressure regulator is positioned in the control line upstream of the reference manifold to maintain the reference manifold at a predetermined pressure level.

Abstract: A method of and apparatus for measuring and monitoring the annulus pressure between coaxial well conduits by providing a pressure measuring means which is adapted to be positioned in the well in the annulus and which is movable in response to pressure, and measuring means measuring the movement of the movable pressure measuring means, and transmitting the measurement to the well surface. Pressure measuring means may include a movable element exposed to the pressure in the annulus and a pressure charge chamber acting on the element opposing the movement caused by the pressure in the annulus. The pressure chamber and movable elements may be annular and surround the exterior of the interior conduit. The measuring means includes sensor means adapted to be moved in the well in the interior of the interior conduit to a position adjacent but spaced from the pressure measuring means for providing measurements by signal waves.

Abstract: A valve assembly for controlling the flow of hydraulic fluid through a subsea control system providing hydraulic control of underwater equipment and having a female member adapted to be connected to the underwater equipment and having a retrievable male member coacting with the female member in which each of said members includes a plurality of flow control passageways. A laminated manifold block having top, middle and lower layers is connected to the top of the male member and supports a plurality of individual valve housings releasably secured to the top layer of the manifold block for receiving control valves. The laminated manifold block includes fluid supply, fluid exhaust and fluid outlet passageways between the control valves and the controlled underwater equipment. The laminated manifold block is longer than the width of the male member thereby accommodating larger control valves to provide an adequate volume of fluid for control purposes.