Abstract: A removeable off-ice training blade for use in a convertible ice skate on a non-ice training surface. The blade has an upper retention surface shaped to engage the interior of a blade-holding groove and retention mechanism of the skate and has a lower tread to engage the non-ice training surface. Two side surfaces extend substantially perpendicularly from the lower tread to meet the upper retention surface. The tread surface comprises reflective non-cutting axial edges, to negate any destruction of the non-ice training surface during use of the blade. Certain embodiments of the training blade will include a tread surface that is wider than the upper retention surface, achieved with multiple lower profiles and cross-sections of the blade. Insofar as the training blade will not permit on-ice skating use, it can be removed from the skate for replacement with an ice blade having cutting edges. A skate incorporating the blade, and a related exercise method, are also disclosed.

Abstract: A tandem-wing unmanned aircraft system (UAS) includes forward and aft wings mounted to the fuselage by frangible spar elements, the forward wings in a shoulder-wing configuration and the aft wings in a low-wing configuration. The forward and aft wings may incorporate fill-span multifunctional control surfaces on their trailing edges. The wing design prevents interference with airflow over the fuselage into a tail-mounted ducted propeller assembly, which pivots to provide vectored thrust. A nose compartment at the nose end of the fuselage may include a forward-mounted camera with a hemispherical field of view, the nose camera protected by transparent exterior panels. A ventral cargo compartment mounted amidships may include a ventral camera gimbal-mounted to provide an overhead perspective; the ventral camera may be gimbal-mounted for articulation along multiple rotational axes to provide additional views of the UAS exterior.

Abstract: A vertical takeoff and landing (VTOL) unmanned aircraft system (UAS) may be uniquely capable of VTOL via a folded wing design while also configured for powered flight as the wings are extended. In a powered flight regime with wings extended, the VTOL UAS may maintain controlled powered flight as a twin pusher canard design. In a zero airspeed (or near zero airspeed) nose up attitude in a VTOL flight regime with the wings folded, the unmanned aircraft system may maintain controlled flight using main engine thrust as well as vectored thrust as a vertical takeoff and landing aircraft. An airborne transition from VTOL flight regime to powered flight and vice versa may allow the VTOL UAS continuous controlled flight in each regime.

Abstract: A multi-rotor UAV comprises a body and a plurality of rotor arms extending radially from the body. A rotor assembly is connected to an outside end of each rotor arm. An attachment interface is connected to the body and provides rotor arm attachment points for attaching the rotor arms to the body and pivoting the rotor arms from an unfolded operating position, to a folded position wherein the rotor arms are pivoted such that an outer arm portion of each rotor arm is enabled to cross the pivot end and an inner arm portion of an adjacent rotor arm.

Abstract: A multi-rotor UAV comprises a body and a plurality of rotor arms extending radially from the body. A rotor assembly is connected to an outside end of each rotor arm. An attachment interface is connected to the body and provides rotor arm attachment points for attaching the rotor arms to the body and pivoting the rotor arms from an unfolded operating position, to a folded position wherein the rotor arms are pivoted such that an outer arm portion of each rotor arm is enabled to cross the pivot end and an inner arm portion of an adjacent or arm.

Abstract: A combination rotor and wheel assembly for an unmanned vehicle with ground and aerial mobility has a rotor arm adapted to be attached at an inner end thereof to a vehicle body. A rotor is rotatably connected to an outer end of the rotor arm about a rotor axis, and a rotor drive mounted on the rotor arm rotates the rotor such that the rotor exerts an upward lift force on the rotor arm. An open spoked wheel is rotatably connected about the rotor axis independent of the rotor The diameter of the wheel is greater than that of the rotor, and a bottom edge of the wheel is below the rotor. A wheel drive rotates the wheel. Vehicles can have various numbers and orientations of the rotor and wheel assembly to provide aerial and ground mobility.

Abstract: A vertical takeoff and landing (VTOL) unmanned aircraft system (UAS) may be uniquely capable of VTOL via a folded wing design while also configured for powered flight as the wings are extended. In a powered flight regime with wings extended, the VTOL UAS may maintain controlled powered flight as a twin pusher canard design. In a zero airspeed (or near zero airspeed) nose up attitude in a VTOL flight regime with the wings folded, the unmanned aircraft system may maintain controlled flight using main engine thrust as well as vectored thrust as a vertical takeoff and landing aircraft. An airborne transition from VTOL flight regime to powered flight and vice versa may allow the VTOL UAS continuous controlled flight in each regime.

Abstract: A combination rotor and wheel assembly for an unmanned vehicle with ground and aerial mobility has a rotor arm adapted to be attached at an inner end thereof to a vehicle body. A rotor is rotatably connected to an outer end of the rotor arm about a rotor axis, and a rotor drive mounted on the rotor arm rotates the rotor such that the rotor exerts an upward lift force on the rotor arm. An open spoked wheel is rotatably connected about the rotor axis independent of the rotor The diameter of the wheel is greater than that of the rotor, and a bottom edge of the wheel is below the rotor. A wheel drive rotates the wheel. Vehicles can have various numbers and orientations of the rotor and wheel assembly to provide aerial and ground mobility.

Abstract: A rotary wing aircraft apparatus has arms extending from a body, and a rotor assembly attached to an end of each arm. Each rotor assembly has a rotor blade releasably attached by a lock mechanism. A clockwise rotor blade is releasably attached to a first rotor assembly by engagement in a clockwise lock mechanism, and a counterclockwise rotor blade is releasably attached to a second rotor assembly by engagement in a counterclockwise lock mechanism. The clockwise rotor blade is engageable only with the clockwise lock mechanism and the counterclockwise rotor blade is engageable only with the counterclockwise lock mechanism and cannot be engaged in the clockwise lock mechanism. A leg extends down from each rotor assembly to support the apparatus on the ground.

Abstract: A combination rotor and wheel assembly for an unmanned vehicle with ground and aerial mobility has a rotor arm adapted to be attached at an inner end thereof to a vehicle body. A rotor is rotatably connected to an outer end of the rotor arm about a rotor axis, and a rotor drive mounted on the rotor arm rotates the rotor such that the rotor exerts an upward lift force on the rotor arm. An open spoked wheel is rotatably connected about the rotor axis independent of the rotor The diameter of the wheel is greater than that of the rotor, and a bottom edge of the wheel is below the rotor. A wheel drive rotates the wheel. Vehicles can have various numbers and orientations of the rotor and wheel assembly to provide aerial and ground mobility.

Abstract: A rotary wing aircraft apparatus has arms extending from a body, and a rotor assembly attached to an end of each arm. Each rotor assembly has a rotor blade releasably attached by a lock mechanism. A clockwise rotor blade is releasably attached to a first rotor assembly by engagement in a clockwise lock mechanism, and a counterclockwise rotor blade is releasably attached to a second rotor assembly by engagement in a counterclockwise lock mechanism. The clockwise rotor blade is engageable only with the clockwise lock mechanism and the counterclockwise rotor blade is engageable only with the counterclockwise lock mechanism and cannot be engaged in the clockwise lock mechanism. A leg extends down from each rotor assembly to support the apparatus on the ground.

Abstract: A circular folding wheel has a center wheel section encompassing the center of a circle and adapted to be mounted to an axle at the center, with a side substantially corresponding to a chord of the circle. A wheel segment is pivotally attached to the center wheel section about a pivot axis extending along the side of the center wheel section. The wheel segment is movable from a rolling orientation, where the outer edge of the wheel segment is aligned with an outer edge of the center wheel section such that the folding wheel takes a rolling circular shape, to a folded orientation where the wheel segment extends laterally away from the pivot axis. Two, three, or more wheel segments can be pivotally attached to corresponding sides of the center wheel section.

Abstract: A circular folding wheel has a center wheel section encompassing the center of a circle and adapted to be mounted to an axle at the center, with a side substantially corresponding to a chord of the circle. A wheel segment is pivotally attached to the center wheel section about a pivot axis extending along the side of the center wheel section. The wheel segment is movable from a rolling orientation, where the outer edge of the wheel segment is aligned with an outer edge of the center wheel section such that the folding wheel takes a rolling circular shape, to a folded orientation where the wheel segment extends laterally away from the pivot axis. Two, three, or more wheel segments can be pivotally attached to corresponding sides of the center wheel section.

Abstract: A rotary wing aircraft apparatus includes a body and a rotor pair connected to the body by an arm. The rotor pair has an upper rotor driven by an upper motor and rotating about an upper rotor axis and a lower rotor driven by a lower motor and rotating about a lower rotor axis. The upper and lower rotor axes are tilted with respect to each other. Tilting the axes away from the arm increases the distance from the rotor blades to the arm, and decreases the risk of the blades of the rotor contacting the arm. In an aircraft with a plurality of arms extending from the body, and a rotor assembly connected to each arm, the arms can be pivoted from a flying position, where the arms extend laterally outward to a folded position where the arms are positioned substantially parallel and adjacent to each other.

Abstract: A rotary wing aircraft apparatus includes a body and a rotor pair connected to the body by an arm. The rotor pair has an upper rotor driven by an upper motor and rotating about an upper rotor axis and a lower rotor driven by a lower motor and rotating about a lower rotor axis. The upper and lower rotor axes are tilted with respect to each other. Tilting the axes away from the arm increases the distance from the rotor blades to the arm, and decreases the risk of the blades of the rotor contacting the arm. In an aircraft with a plurality of arms extending from the body, and a rotor assembly connected to each arm, the arms can be pivoted from a flying position, where the arms extend laterally outward to a folded position where the arms are positioned substantially parallel and adjacent to each other.

Abstract: A rotary wing aircraft apparatus includes a body and a rotor pair connected to the body by an arm. The rotor pair has an upper rotor driven by an upper motor and rotating about an upper rotor axis and a lower rotor driven by a lower motor and rotating about a lower rotor axis. The upper and lower rotor axes are tilted with respect to each other. Tilting the axes away from the arm increases the distance from the rotor blades to the arm, and decreases the risk of the blades of the rotor contacting the arm. In an aircraft with a plurality of arms extending from the body, and a rotor assembly connected to each arm, the arms can be pivoted from a flying position, where the arms extend laterally outward to a folded position where the arms are positioned substantially parallel and adjacent to each other.

Abstract: A rotary wing aircraft apparatus includes a body and a rotor pair connected to the body by an arm. The rotor pair has an upper rotor driven by an upper motor and rotating about an upper rotor axis and a lower rotor driven by a lower motor and rotating about a lower rotor axis. The upper and lower rotor axes are tilted with respect to each other. Tilting the axes away from the arm increases the distance from the rotor blades to the arm, and decreases the risk of the blades of the rotor contacting the arm. In an aircraft with a plurality of arms extending from the body, and a rotor assembly connected to each arm, the arms can be pivoted from a flying position, where the arms extend laterally outward to a folded position where the arms are positioned substantially parallel and adjacent to each other.

Abstract: A rotary wing aircraft is provided having at least three rotor pairs. Each rotor pair has an upper rotor and a lower rotor. During operation, the upper rotor and lower rotor rotate around a shared rotor axis with the upper rotor rotating in a first direction and the lower rotor rotating in an opposite direction By independently controlling the speed of rotation of each upper rotor and each lower rotor the aircraft can be made to ascend, descend, move forward, move backward, move side to side, yaw right and yaw left by only varying the relative speeds of rotations of the upper rotors and lower rotors.