Abstract: An aircraft propulsion system includes at least first and second electrical generators, each being configured to provide electrical power to a respective first and second AC electrical network. The system further comprises at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor, and a DC electrical network electrically coupled to the first and second AC networks via respective first and second AC to DC converters, and to a further electrical motor, the further electrical motor being coupled to a propulsor.

Abstract: An aircraft propulsion system includes at least first and second electrical generators, each being configured to provide electrical power to a respective first and second AC electrical network. The system further comprises at least first and second AC electrical motors directly electrically coupled to a respective AC network and coupled to a respective propulsor, and a DC electrical network electrically coupled to the first and second AC networks via respective first and second AC to DC converters, and to a further electrical motor, the further electrical motor being coupled to a propulsor.

Abstract: An aircraft propulsion system (10) comprises at least first and second electrical generators (15a, 15b), each being configured to provide electrical power to a respective first and second AC electrical network (16a, 16b). The system (10) further comprises at least first and second AC electrical motors (19a, 19b) directly electrically coupled to a respective AC network (16a, 16b) and coupled to a respective propulsor (4), and a DC electrical network electrically coupled to the first and second AC networks (16a, 16b) via respective first and second AC to DC converters (17a, 17b), and to a further electrical motor 19c), the further electrical motor (19c) being coupled to a propulsor (4).

Abstract: Energy conversion apparatus comprising: an electrical machine including a rotor arranged to rotate about an axis, the rotor defining a first cavity therein; power electronic circuitry arranged at least partially around the axis and defining a second cavity therein, the power electronic circuitry being positioned adjacent to the electrical machine; a heat pipe positioned within the first cavity of the rotor and within the second cavity defined by the power electronic circuitry, the heat pipe being arranged to receive thermal energy from the rotor; and a cooling arrangement positioned at least partially within the second cavity and arranged to receive thermal energy from the power electronic circuitry and from the heat pipe.

Abstract: A power electronics module is provided having one or more power converter semiconductor components. The power electronics module further has a substrate having a first surface to which the one or more components are mounted, and having an opposing second surface from which project a plurality of heat transfer formations for enhancing heat transfer from the substrate. The power electronics module further has a coolant housing which sealingly connects to the substrate to form a void over the heat transfer formations of the second surface. The coolant housing has an inlet for directing a flow of an electrically insulating coolant into the void and an outlet for removing the coolant flow from the void, whereby heat generated during operation of the one or more components is transferred into the coolant flow via the substrate.

Abstract: An aircraft propulsion system (10) comprises at least first and second electrical generators (15a, 15b), each being configured to provide electrical power to a respective first and second AC electrical network (16a, 16b). The system (10) further comprises at least first and second AC electrical motors (19a, 19b) directly electrically coupled to a respective AC network (16a, 16b) and coupled to a respective propulsor (4), and a DC electrical network electrically coupled to the first and second AC networks (16a, 16b) via respective first and second AC to DC converters (17a, 17b), and to a further electrical motor 19c), the further electrical motor (19c) being coupled to a propulsor (4).

Abstract: A power electronics module is provided having one or more power converter semiconductor components. The power electronics module further has a substrate having a first surface to which the one or more components are mounted, and having an opposing second surface from which project a plurality of heat transfer formations for enhancing heat transfer from the substrate. The power electronics module further has a coolant housing which sealingly connects to the substrate to form a void over the heat transfer formations of the second surface. The coolant housing has an inlet for directing a flow of an electrically insulating coolant into the void and an outlet for removing the coolant flow from the void, whereby heat generated during operation of the one or more components is transferred into the coolant flow via the substrate.

Abstract: Energy conversion apparatus comprising: an electrical machine including a rotor arranged to rotate about an axis, the rotor defining a first cavity therein; power electronic circuitry arranged at least partially around the axis and defining a second cavity therein, the power electronic circuitry being positioned adjacent to the electrical machine; a heat pipe positioned within the first cavity of the rotor and within the second cavity defined by the power electronic circuitry, the heat pipe being arranged to receive thermal energy from the rotor; and a cooling arrangement positioned at least partially within the second cavity and arranged to receive thermal energy from the power electronic circuitry and from the heat pipe.

Abstract: A collimator for a therapeutic linear accelerator comprising first and second opposed arrays of individually longitudinally moveable elongate leaves, and a blocking element arranged transverse to the two arrays and moveable in that transverse direction, thereby to move into a gap between the tips of a leaf from the first array and a leaf from the second array. The blocking element and the two arrays can be in the same plane, thereby reducing the overall height of the device. As the tips of the leaves are usually profiled, it is preferred that the side edges of the blocking element are profiled to a complementary shape. The side edges of the leaves are usually non-vertical in order to allow for the divergence of the radiation beam. Each leaf will have a different angle. Accordingly, it is preferred that the tip of the blocking element has a variable angle, in order to match the angle of whichever leaf is adjacent.

Abstract: A collimator for a therapeutic linear accelerator comprising first and second opposed arrays of individually longitudinally moveable elongate leaves, and a blocking element arranged transverse to the two arrays and moveable in that transverse direction, thereby to move into a gap between the tips of a leaf from the first array and a leaf from the second array. The blocking element and the two arrays can be in the same plane, thereby reducing the overall height of the device. As the tips of the leaves are usually profiled, it is preferred that the side edges of the blocking element are profiled to a complementary shape. The side edges of the leaves are usually non-vertical in order to allow for the divergence of the radiation beam. Each leaf will have a different angle. Accordingly, it is preferred that the tip of the blocking element has a variable angle, in order to match the angle of whichever leaf is adjacent.

Abstract: A switch actuation assembly is provided with a support means for supporting the switch in a fixed position relative to orientations of a moveable member. A motion response element is operably connected to the moveable member for being moved in one of two directions in response to movement of the moveable member toward one of the orientations and for being moved in the other of the two directions in response to the movement of the moveable member toward the other of the two orientations. An actuating member is provided for engaging the switch to actuate the switch from a first position to a second position. The actuating member is in frictional contact with the motion response element whereby the actuating member is moved by the response element until any force of resistance to the movement of the actuating member exceeds the static friction force.

Abstract: A combined depth-control and wing-lift hydraulic circuit is disclosed. The circuit is preferably used in combination with a farm implement having a tool bar. The tool bar is horizontally disposed relative to the ground, and is carried by the implement. The hydraulic circuit comprises means to raise and lower the tool bar relative to the ground, thereby to effect depth control. The tool bar includes pivotally connected wings. Each wing carries an associated wing wheel. The hydraulic circuit includes means for causing rotative movement of each wing about its associated tool bar pivot between a substantially horizontally-disposed position and a substantially vertically-disposed position, relative to the ground, and for further causing each wing to be selectively disposed at one of these positions, thereby to effect wing lift. Each wing wheel is coupled to, and is distally spaced from and located beneath, its associated wing structure when such wing is in the substantially horizontally-disposed position.

Abstract: An implement-mounting linkage mechanism for pivotally connecting a frame to a wheeled implement is disclosed. The mechanism is preferably used for pivotally connecting a wheeled load-bearing frame to the backside of a wheeled farm implement. The frame includes wheels adjustable relative to the frame for raising and lowering the frame relative to the ground. The frame preferably includes a plurality of soil-engaging ground-tool implements mounted thereon. The mounting-linkage mechanism of the present invention incorporates a novel non-parallel four-point design which virtually eliminates negative hitch weight when the frame is raised above the ground, in the static case. On the other hand, the novel design results in a net downward force being imposed upon the ground-tool implements when the frame is lowered for soil engagement, in the dynamic case.