Abstract: A charged particle buncher includes a series of spaced apart electrodes arranged to generate a shaped electric field. The series includes a first electrode, a last electrode and one- or more intermediate electrodes. The charged particle buncher includes a waveform device attached to the electrodes and configured to apply a periodic potential waveform to each electrode independently in a manner so as to form a quasi-electrostatic time varying potential gradient between adjacent electrodes and to cause spatial distribution of charged particles that form a plurality of nodes and antinodes. The nodes have a charged particle density and the antinodes have substantially no charged particle density, and the nodes and the antinodes are formed from a charged particle beam configured to hit the target.

Abstract: A squeezer holder device for the holding a hand rivet squeezer on a bench top for improved part control and squeezer operation. The squeezer holder device also provides convenient storage for a hand squeezer and associated dies. The central feature of the invention is the simple slot and die holders designed into a single block. The squeezer holder device allows the user to position a squeezer on any benchtop at a user selected orientation. The squeezer holder device enables accurate control of parts with one hand throughout squeezer operation by using the table surface to operate the lower squeezer lever. The squeezer holder device can be easily slid around a benchtop with the squeezer and dies between operations. When squeezer use is completed the squeezer holder device holds the squeezer in an upright space saving position with associated dies.

Abstract: A dual, counter rotating, coaxial rotor system provides an upper and lower rotor system, with a reduced axial rotor separation distance along a common axis by way of rotor tip position sensing and rotor position controls to avoid tip contact.

Abstract: A dual, counter rotating, coaxial rotor system provides an upper and lower rotor system, with a reduced axial rotor separation distance along a common axis by way of rotor tip position sensing and rotor position controls to avoid tip contact.

Abstract: A drag reduction system extends from an underside of a VTOL aircraft forward of a four-point sling system. The four-point sling system carries an external load close to an underside of the airframe and oriented along the aircraft longitudinal axis. The drag reduction system includes a retractable shield mounted beneath the underside of the aircraft which reduces drag of the external sling load and reduces the airloads on the external load.

Abstract: A translational propulsion system for a hybrid UAV includes a pusher prop mounted to the rear of the aircraft with its rotational axis oriented substantially horizontal. The pusher prop is mounted to a driveshaft assembly which transmits power from a coaxial transmission to drive the pusher prop. The driveshaft assembly includes a shaft which defines an axis of rotation. The shaft is mounted to the transmission through a crown spline assembly and is supported by a single bearing. The crown spline and the inherent slop in the bearing accommodates angular deflection and misalignment. The length of the shaft is selected such that the force on the crown spline is less than an allowable level.

Abstract: A cooling system for a hybrid aircraft includes an inlet which extends through the body to communicate airflow to a powerplant subsystem and out through an exhaust within a rotor duct. In a hover mode, there is a significant low-pressure area created inside the rotor duct by the rotor system. The low-pressure area within the rotor duct assists in drawing air through the inlet and over the engine via the exhaust. A cooling fan is located adjacent the inlet to augment cooling-air flow. The cooling fan is smaller than conventional practice because it does not have to provide the entire pressure difference to force air-cooling flow over the engine. In a transition mode, the low-pressure area created inside the rotor duct decreases but ram air pressure through the inlet increases. In a forward flight mode, the pressure inside the rotor duct is approximately atmospheric but significant ram air is provided from the inlet due to forward flight speed.

Abstract: An unmanned aerial vehicle that includes a fuselage with a partial toroidal forward portion, and an aft portion. A duct is formed through the fuselage and extends from the top to the bottom of the fuselage. Two counter-rotating rotor assemblies are mounted within the duct for providing downward thrust through the duct. The rotor assemblies are supported by a plurality of support struts. At least one engine is mounted within the fuselage and engages with the rotor assemblies. A pusher prop assembly is mounted to the aft portion of the fuselage. The pusher prop assembly is designed to provide forward thrust along the longitudinal axis of the aircraft. The pusher prop assembly includes a drive shaft that is engaged with the engine. A plurality of propellers are attached to and rotated by the drive shaft. A shroud is mounted to the aft portion of the fuselage around the propellers and is operative for channeling the air passing through the propellers in a substantially aft direction.

Abstract: A method for reducing a nose-up pitching moment in an unmanned aerial vehicle during forward flight. The unmanned aerial vehicle includes counter-rotating rotor assemblies that are mounted within a duct. Each rotor assembly includes a plurality of rotor blades. The method involves adjusting the rotor blades to have substantially zero pitch. Then rotating the rotor assemblies to produce a virtual plane across the duct. The virtual plane is operative for substantially deflecting air passing over the fuselage away from the duct. In one embodiment of the invention, the method involves the further step of obstructing at least a portion of the bottom of the duct to inhibit air that is flowing across the bottom of the duct from passing into the duct.