Abstract: In some embodiments, a rotorcraft includes a fuselage, a tailboom, a drive system and a variable thrust cross-flow fan system. The cross-flow fan system includes a cross-flow fan assembly that is mechanically coupled to a drive shaft and operable to rotate with the drive shaft about a longitudinal axis. The cross-flow fan assembly includes first and second driver plates having a plurality of blades rotatably mounted therebetween. The blades are disposed radially outwardly from the longitudinal axis and have a generally circular path of travel when the cross-flow fan assembly rotates about the longitudinal axis. The blades are moveable between a plurality of pitch angle configurations. A control assembly is coupled to the blades. The control assembly is operable to change the pitch angle configuration of the blades to generate variable thrust at a substantially constant rotational speed of the cross-flow fan assembly.

Abstract: In some embodiments, a rotorcraft includes a fuselage, a tailboom, a drive system and a variable thrust cross-flow fan system. The cross-flow fan system includes a cross-flow fan assembly that is mechanically coupled to a drive shaft and operable to rotate with the drive shaft about a longitudinal axis. The cross-flow fan assembly includes first and second driver plates having a plurality of blades rotatably mounted therebetween. The blades are disposed radially outwardly from the longitudinal axis and have a generally circular path of travel when the cross-flow fan assembly rotates about the longitudinal axis. The blades are moveable between a plurality of pitch angle configurations. A control assembly is coupled to the blades. The control assembly is operable to change the pitch angle configuration of the blades to generate variable thrust at a substantially constant rotational speed of the cross-flow fan assembly.

Abstract: According to one embodiment, a constant velocity (CV) joint includes a first yoke, a second yoke, and a control mechanism. The first yoke is configured to be rotatably coupled to an input device about a first axis and configured to receive the input device through a first opening. The second yoke is rotatably coupled to the first yoke about a second axis and rotatably coupled to an output device about a third axis. The control mechanism is adapted to constrain the first yoke and the second yoke so as to achieve a substantially CV characteristic between the input device and the output device.

Abstract: A convertible helicopter ring member includes a ring member and a drive mechanism. The drive mechanism orients the ring member substantially in-plane with a tail rotor of a helicopter during a first mode of helicopter operation and orients the ring member substantially off-plane with the tail rotor of the helicopter during a second mode of helicopter operation that is different from the first mode.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A transmission for a rotary-wing aircraft has a differential torque-splitting mechanism associated with an input shaft. The differential has a drive disk coaxial with the shaft and integral in rotation with the shaft, a first driven member coaxial with the shaft and generally adjacent the drive disk, and a second driven member coaxial with the shaft and generally adjacent the drive disk. At least one pin engages each of the drive disk, the first driven member, and the second driven member. The first driven member is configured to drive a first transfer gear, and the second driven member is configured to drive a second transfer gear for supplying torque to a bull gear associated with a rotor mast.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A transmission for a rotary-wing aircraft has a differential torque-splitting mechanism associated with an input shaft. The differential has a drive disk coaxial with the shaft and integral in rotation with the shaft, a first driven member coaxial with the shaft and generally adjacent the drive disk, and a second driven member coaxial with the shaft and generally adjacent the drive disk. At least one pin engages each of the drive disk, the first driven member, and the second driven member. The first driven member is configured to drive a first transfer gear, and the second driven member is configured to drive a second transfer gear for supplying torque to a bull gear associated with a rotor mast.

Abstract: A transmission for a rotary-wing aircraft has a differential torque-splitting mechanism associated with an input shaft. The differential has a drive disk coaxial with the shaft and integral in rotation with the shaft, a first driven member coaxial with the shaft and generally adjacent the drive disk, and a second driven member coaxial with the shaft and generally adjacent the drive disk. At least one pin engages each of the drive disk, the first driven member, and the second driven member. The first driven member is configured to drive a first transfer gear, and the second driven member is configured to drive a second transfer gear for supplying torque to a bull gear associated with a rotor mast.

Abstract: A robust underwater communication system, for communication between an acoustic signal transmitter and a remotely positioned acoustic signal receiver, wherein transmitted data is carried by a plurality of symbols each having two components one of which comprises a distinctive bit code and the other of which appertains to the character of the symbol as a whole wherein the character of successive symbols is stepped through a predetermined continuously repeating sequence of distinctive steps each of which occurs once in the sequence, the signal receiver being operated synchronously with the signal transmitter and comprising a correlator arrangement responsive both to the bit code and to the character of received signals for effecting demodulation and having a plurality of outputs one for each symbol, so that as each symbol is detected a signal on the output to which it corresponds pre-dominates and amplitude detector means responsive to the outputs from the correlator arrangement for providing an output signal c

Abstract: A robust underwater communication system, for communication between an acoustic signal transmitter and a remotely positioned acoustic signal receiver, wherein transmitted data is carried by a plurality of symbols each having two components one of which comprises a distinctive bit code and the other of which appertains to the character of the symbol as a whole wherein the character of successive symbols is stepped through a predetermined continuously repeating sequence of distinctive steps each of which occurs once in the sequence, the signal receiver being operated synchronously with the signal transmitter and comprising a correlator arrangement responsive both to the bit code and to the character of received signals for effecting demodulation and having a plurality of outputs one for each symbol, so that as each symbol is detected a signal on the output to which it corresponds pre-dominates and amplitude detector means responsive to the outputs from the correlator arrangement for providing an output signal c

Abstract: A transmission for a rotary-wing aircraft has a differential torque-splitting mechanism associated with an input shaft. The differential has a drive disk coaxial with the shaft and integral in rotation with the shaft, a first driven member coaxial with the shaft and generally adjacent the drive disk, and a second driven member coaxial with the shaft and generally adjacent the drive disk. At least one pin engages each of the drive disk, the first driven member, and the second driven member. The first driven member is configured to drive a first transfer gear, and the second driven member is configured to drive a second transfer gear for supplying torque to a bull gear associated with a rotor mast.

Abstract: A ducted fan for a helicopter includes a transverse duct and a counter-torque device supported within the duct. The counter-torque device includes a rotor rotatably mounted within the duct and a stator fixedly mounted within the duct downstream from the rotor. The rotor includes a rotor hub having a rotor axis, and rotor blades extending from the hub. The Rotor blades have a modulated angular distribution about the rotor axis. The stator includes a stator hub, and a plurality of stator vanes distributed around the stator hub. The stator vanes are angularly modulated around the stator hub.

Abstract: A rotorcraft having an enhanced configuration in which a simple wing and a propulsive anti-torque system are combined is disclosed. The propulsive anti-torque system includes an anti-torque thruster system in which a variable pitch fan is installed internal to the tail boom of the rotorcraft and an anti-torque thruster nozzle is mounted at the extremity of the tail boom. The fan is driven directly from the main rotor drive. The configuration and location of the fan allows the primary exhaust from the engine to be mixed with the compressed air flow from the fan. The mixed air flow from the fan and the engine passes through the tail boom and out the thruster nozzle.

Abstract: A proprotor blade (27a, 27b, 127a, 127b) having a fixed, spanwise, leading edge slot (215) located in at least the inboard portion of the proprotor is disclosed. The slot (215) is formed by a selectively shaped slat (217) disposed in a selectively shaped recessed area (219) located at the leading edge (202) of the main portion of the proprotor blade. The slot (215) is selectively shaped so the a portion of the airflow over the lower airfoil surface of the proprotor blade is diverted between the main portion of the proprotor blade and the slat (217) and exits at the upper airfoil surface of the proprotor blade. The present invention may be used on both military-type tiltrotor aircraft (11) and civilian-type tiltrotor aircraft (111) with only minor variations to accommodate the different shapes of the proprotor blades.

Abstract: An adjustable plant support system with a vertically oriented shaft, an adjustable clamp assembly and a horizontally oriented shaft. The clamp assembly is capable of releasably retaining both the vertical shaft and the horizontal shaft. A preferred embodiment includes the clamp assembly having a rigid body with a vertically disposed aperture, a horizontally disposed aperture and a U shaped cutout area located in front of the apertures that receives a cam type clamping lever that is rotatably pinned to the remaining upper and lower legs formed by the U shaped cutout. The vertical aperture and the horizontal aperture are in adjoining proximity to each other so that when the shafts are in place, the cam lever pushes against the vertical shaft which in turn pushes against the horizontal shaft thereby locking them in place.

Abstract: Vegetable Cradle with a rigid support platform that is radially curved when looking at an end view and straight and parallel to the ground when looking at a side view. A plurality of legs are attached the underside of the platform to keep the lowest portion of the platform approximately one inch off the ground. The platform has a plurality of ventilation slots and or apertures thereby allowing a fruit or vegetable to be ventilated. The platform is constructed of transparent material such as clear acrylic plastic. In a preferred embodiment, the legs include a broad foot to help prevent the legs from sinking into the ground.