Abstract: An anti-flutter structure, or reinforcement panel, for a roof panel supported on transversely extending roof bows. The reinforcement panel is attached to at least one of the roof bows with the flanges being disposed above the roof bow. The flanges extend longitudinally, and are resiliently compressed by the roof panel. The reinforcement panel has a body and flanges laterally flanking the body. The body is attached to one of the roof bows with the flanges being disposed above the roof bow. The anti-flutter material is disposed between the flanges and the roof panel.

Abstract: A motor vehicle has a receiving element for a torsion bar. In order to devise a motor vehicle which has a receiving element for a torsion bar and in which the receiving element has a simple design and reduced weight while avoiding drawbacks in respect of the sealing effect and the available space, the receiving element consists essentially of a monolithic extruded profile.

Abstract: A tailgate includes an internal panel, external panel, upper panel, lower panel, latching mechanism, and access panel. The internal and external panels are each secured to the upper and lower panels. A cavity is defined between the upper, lower, internal, and external panels. The latching mechanism is disposed within the cavity and is linked to a handle located on the external panel. The access panel is secured and extends adjacent to the internal panel beyond the upper panel. The cavity is exposed when the access panel is removed.

Abstract: A powered side panel system is used in conjunction with a loading bed found on trailers and other flatbed vehicles. The system includes a side panel having a vertical member. The side panel is configured to pivot about a panel axis in communication with the trailer. A lever arm extends between the side panel and an actuator. The actuator pivots the lever arm about a lever axis. The lever arm contacts the vertical member and controls the rate of radial motion of the side panel about the panel axis. A control unit is configured to regulate the operation of the actuator device.

Abstract: A tracked vehicle with a chassis comprising an upper frame structure connected to a lower frame structure, the lower frame structure spanning a longitudinal distance along a longitudinal direction of the vehicle, wherein over a first portion of the longitudinal distance, the lower frame structure overlaps with the upper frame structure and wherein over a second portion of the longitudinal distance, the lower frame structure does not overlap with the upper frame structure. The tracked vehicle may also comprise an operator cabin, power plant mounted to the upper frame structure and a plurality of track assemblies for traction of the tracked vehicle. Each track assembly is mounted to the lower frame structure of the chassis and comprises a drive wheel; an end wheel; and a plurality of support wheels therebetween; and an endless track disposed around the plurality of wheels for engaging a ground on which the tracked vehicle travels.

Abstract: A carriage assembly includes a primary frame, a first idler wheel mounted to the primary frame, and a secondary frame pivotably mounted to the primary frame. The carriage assembly further includes an idler wheel assembly coupled to the secondary frame and movable with respect to the secondary frame along a longitudinal axis of the idler wheel assembly. The idler wheel assembly includes at least one second idler wheel and at least one third idler wheel mounted to the idler wheel assembly such that the second idler wheel is located between the first idler wheel and the third idler wheel. The first idler wheel is configured to pivot with the primary frame relative to the secondary frame, and the second idler wheel and the third idler wheel are configured to move with the idler wheel assembly relative to the secondary frame along the longitudinal axis of the idler wheel assembly.

Abstract: Damping system for an endless track system, comprising: Damper operatively connectable between frame members for damping relative movement therebetween, including: cylinder and piston movable therewithin forming variable volume chamber containing liquid. Reservoir containing liquid and gas connected to chamber. Conduits connecting chamber to reservoir for allowing liquid to flow therebetween to move the piston. Gas in reservoir applying hydrostatic pressure to liquid, biasing piston toward an extended position and causing piston to move theretowards when load on endless track system is decreased, and causing piston to move toward a retracted position when load on endless track system is increased.

Abstract: A crawler track includes a link and is driven in a direction of travel by a sprocket having a plurality of teeth. The link includes a pad, a first grouser, and a second grouser. The pad defines a first surface, a second surface opposite the first surface, a first end, and a second end spaced apart from the first end along the direction of travel. The pad defines at least one opening extending through the pad between the first surface and the second surface, and the opening is operable to receive a sprocket tooth. The first grouser is positioned on the first surface proximate the first end of the pad, while the second grouser is positioned on the first surface proximate the second end of the pad. The first grouser and the second grouser extend in a direction substantially perpendicular to the direction of travel of the track.

Abstract: A two wheeled robot with a pair of motorized wheels mounted on each end of a body and a rearwardly extending tail. The body comprising a chassis with sides and exterior side surfaces and providing an accessory mounting interface. The interface having a matrixical arrangement of threaded holes and one or more landings, the landings having an outwardly facing planar landing surface with hole openings at the landing surface. An accessory with a robot mounting interface cooperates with the chassis at the accessory mounting interface such that prior to fastening the accessory has a single degree of freedom of movement. Screws extend through portions of the accessory into select ones of the threaded holes of the matrixical arrangement.

Abstract: A composite climb structure includes a climber, a horizontal planar structure, and a ramp coupled on to a base plate. The horizontal planar structure and the ramp are collinearly situated on opposite sides of the climber. The climber is pressed by a robotic vehicle moving on to it from the horizontal planar structure, the climber being pressed to a final position, wherein the angle of elevation (BOC) of the climber is same as the angle of elevation of the ramp, thereby facilitating traversal of the robotic vehicle from the horizontal planar structure on to the ramp.

Abstract: A fender assembly for a tractor, as well as a tractor having such a fender assembly. The fender assembly is constructed as first and second fender parts, connected via a rail. The rail has a partial spiral or helical shape. As a result, the second fender part is moveable on the rail along a path substantially parallel to a portion of the circumference of a wheel of the tractor, in a direction downwardly and outwardly relative to the first fender part. This provides a fender assembly allowing for improved access to tractor components located inboard of the fender assembly, as well as allowing for ease of access to the second fender part for an operator standing on the ground adjacent the tractor.

Abstract: A method and assembly station (12) for assembling vehicle body doors (22) utilizes sensing of vehicle body hinge members (26) and door hinge members (28) with the door positioned by a robot (16) to provide assembly with reduced labor cost.

Abstract: The vehicle includes: a vehicle body rotatable about a roll axis; one or more front wheels; a front wheel support supporting the one or more front wheels turnably to a turning direction about a turning axis; one or more rear wheels; an operation input unit to be operated to input a turning direction; a lean angle changing unit for changing a lean angle of the vehicle body in a vehicle width direction about a lean axis different from the roll axis; and a lean control unit for controlling the lean angle changing unit.

Abstract: A variety of scooters are disclosed. In some embodiments, a scooter can include a pivot assembly that allows the scooter to move between a folded and unfolded configuration. The pivot assembly can include a knob that frees a pin from a bracket to allow the scooter to fold. Turing the knob increases compressive forces on elements of the pivot assembly to reduce rattling noise and wobbling movement when the scooter is in use. Some embodiments of the scooter can include a center stand that can be deployed from either side of the scooter deck to stabilize the scooter when the scooter is stationary. Certain embodiments have an ergonomic handgrip.

Abstract: A suspension assembly for a bicycle comprises a lower tubular support configured to be received within a steerer tube of a bicycle fork assembly; an upper tubular support configured to be connected to a stem of a steering assembly above an upper end of the steerer tube; and a spring configured to exert a force that biases the upper and lower tubular supports toward an extended position, wherein the upper and lower tubular supports are configured such that the upper tubular support slides longitudinally relative to the lower tubular support adjacent the stem and above a fork crown of the bicycle fork assembly.

Abstract: A racing bicycle handlebar includes a transverse support connected to a front part and is, in particular, designed in one piece. Two lower handle elements are connected to the transverse support. In order to design additional handle elements which are optionally elastic, two upper handle elements are connected to the transverse support.

Abstract: Disclosed is a thumb switch for operating a mobile communication device and/or electric components of a vehicle, said thumb switch comprising a housing, on which at least one operating element is arranged. In order to allow for ease of operation, the thumb switch has communication electronics for generating control signals for functions that can be carried out on the mobile communication device and/or on at least one electrical component of the vehicle. The invention further relates to control system comprising such a thumb switch.

Abstract: An operating device for a handlebar steered vehicle is basically provided with a base member, an operating member and a handlebar fixing structure. The base member includes a support abutment arranged to contact an outer surface of a handlebar while the operating device is in an installed state. The operating member is pivotally coupled to the base member about a pivot axis. The handlebar fixing structure is coupled to base member. The handlebar fixing structure defines a handlebar arrangement area extending along a handlebar axis. The support abutment being spaced from the handlebar receiving area of the handlebar fixing structure in a handlebar axis direction parallel to the handlebar axis by an axial width with a range from ten millimeters to thirty millimeters.

Abstract: A trailing link, multi-link, suspension assembly for a cycle having improved stability includes a first arm having a first arm fixed pivot and a first arm shock pivot. A shock link has a shock link fixed pivot and a shock link floating pivot. A shock absorber has a first shock mount and a second shock mount. A wheel carrier has a wheel carrier first pivot and a wheel carrier second pivot spaced apart from one another, and a wheel mount that is adapted to be connected to a wheel. A control link has a control link floating pivot and a control link fixed pivot, the control link floating pivot being pivotably connected to the wheel carrier second pivot, and the control link fixed pivot being pivotably connected to the first arm control pivot. A mechanical trail distance increases as the suspension assembly compresses relative to a fully extended state.

Abstract: A trailing link multi-bar suspension assembly for a cycle having improved stability includes a first arm having a first arm fixed pivot and a first arm shock pivot. A shock link has a shock link fixed pivot and a shock link floating pivot. A shock absorber has an inline configuration, a gas spring, a first shock mount, and a second shock mount. A wheel carrier has a wheel carrier first pivot and a wheel carrier second pivot spaced apart from one another, and a wheel mount that is adapted to be connected to a wheel. A control link has a control link floating pivot and a control link fixed pivot, the control link floating pivot being pivotably connected to the wheel carrier second pivot, and the control link fixed pivot being pivotably connected to the first arm control pivot.

Abstract: A bicycle crank assembly comprises a sprocket, a crank axle, a movable member, a torque transmitting member, and a bearing structure. The sprocket has a rotational center axis. The crank axle extends along the rotational center axis. The crank axle includes an internal space. The movable member is movably provided in the internal space to move the sprocket in an axial direction of the rotational center axis. The torque transmitting member is to transmit a pedaling torque from the crank axle to the sprocket. The bearing structure is disposed between the movable member and the crank axle to slidably support the movable member in the axial direction. The bearing structure is disposed at a location different from a location of the torque transmitting member in the axial direction.

Abstract: The disclosure relates to improved friction drive systems, control algorithms for friction drive systems, and automatic traction control for friction drive systems. Embodiments of friction drive systems and methods may improve control over an amount of normal force between a contact surface on a friction drive (e.g., disposed on a drive motor) and a tire or wheel of a wheeled vehicle. Embodiments of friction drive systems and methods may dynamically adjust the normal force between the contact surface and the tire or wheel in response to rapidly changing conditions, such as weather, road surface, and/or tire inflation. Embodiments of an automatic traction control system may adjust the normal force to avoid slippage while minimizing tire wear and maximizing battery efficiency. Embodiments of friction drive systems and methods may allow a user to calibrate or adjust the amount of normal force delivered based on their preferences or based on a selected mode of operation.

Abstract: A catalytic converter for treatment of exhaust gases from a motorcycle engine includes a housing having an upstream end and a downstream end. A housing body extends between the upstream end and the downstream end. A catalyst mantle is positioned within the body of the housing such that a void is formed between the catalyst mantle and the housing body. A catalyst is positioned within the catalyst mantle. An insulator is positioned within the void between the housing body and the catalyst mantle.

Abstract: The present invention relates to a shifting device for a gearing unit, in particular for a vehicle driven using muscle force. The shifting device has a shaft for the mounting of a multiplicity of idler gears. A multiplicity of pawls are assigned to the idler gears and are movably mounted on the shaft in order to connect the idler gears rotationally conjointly to the shaft in at least one direction of rotation. A camshaft is assigned to the pawls and is designed to set different gear-speed stages of the gearing unit, wherein the pawls are assigned in each case one actuating element which is mounted so as to be movable relative to the camshaft and relative to the respective pawl and which is designed to actuate the pawl for the purposes of setting the gear-speed stages.

Abstract: A snowmobile has a frame having a motor module, a tunnel connected to the motor module, a suspension module connected to the motor module, a motor, a handlebar, a ski operatively connected to the handlebar and a front suspension assembly operatively connecting the ski to the suspension module and to the motor module. The front suspension assembly has a suspension arm having a proximal end positioned longitudinally between the motor module and the suspension module. The proximal end pivots about a pivot axis extending through an interior portion of the suspension module. A proximal fastener passes through the proximal end of the suspension arm and extends from the interior portion of the suspension module to the motor module. The proximal fastener thereby pivotally connects the suspension arm to the suspension module and to the motor module about the pivot axis.

Abstract: The invention concerns a cargo transfer vessel for transferring fluid between an offshore production facility and a tanker and a method for transferring the fluid. The cargo transfer vessel comprise a hull having a first and a second outer longitudinal hull side; a deck, propulsion means for actively maintaining the cargo transfer vessel at a predetermined distance from the offshore production facility and the tanker during fluid transfer operations and fluid transfer means for transferring fluid between the offshore structure and the tanker. The vessel is further characterized in that the hull comprises a main hull member and at least one protruding hull member arranged below the cargo transfer vessels water line at each of the outer longitudinal hull sides for suppressing roll of the vessel, wherein the at least one protruding hull member extends at least partly along the hulls longitudinal length, i.e. from the start of the vessel's bow to the end of the vessel's aft.

Abstract: An additional chamber to watercraft that adds both volume and curvature to other compartments or components of the watercraft that are essentially flat is described. The additional chamber provides for modular construction of watercraft for creating volumetric space as well as a curved surface to the outer portion of the watercraft. The chamber advantageously increases the aesthetic appeal of the watercraft as well as provides a surface on which water is discouraged from pooling or collecting on. Various watercrafts having such a chamber are also described.

Abstract: The present invention is directed broadly to a marine vessel (10) comprising a deck (12) mounted to a hull (14) together with a sail (16) coupled to the marine vessel (10) via a mast base assembly (18). The mast base assembly (18) comprises a mast tilt assembly (22). The mast base assembly (18) also comprises a mast base mounting (20) to which the mast tilt assembly (22) is pivotally mounted for movement about a tilt axis (24) between stowed and operative positions. The mast base assembly (18) further comprises a sail slew assembly (26) mounted to the sail (16) associated with the marine vessel (10). The sail slew assembly (26) is operatively coupled to the mast tilt assembly (22) for slewing of the sail (16). The sail (16) is rotated or slewed about a slew axis (28) of the mast tilt assembly (22) to reorient the sail (16) relative to the marine vessel (10).

Abstract: A lift assist mechanism is provided for positioning a hatch cover in relation to a corresponding opening in a hatch frame. The assist mechanism includes a torsion bar and a lifting mechanism. The torsion bar has first and second opposite ends. The first end secures to the hatch frame. The second end connects to a bar spur gear. The lifting assembly includes a lift spur gear and a hinge gear. The lift spur gear engages the bar spur gear. The gears convert an acute angle twist of the bar to substantially perpendicular pivot the hatch cover from the hatch frame.

Abstract: A shallow water anchor and related methods are provided. The shallow water anchor includes a four-bar linkage and a hydraulic actuator for actuating the four-bar linkage. An anchoring element is connected to the four-bar linkage. A hydraulic control arrangement operates the hydraulic actuator to transition the hydraulic actuator between stowed and deployed positions and vice versa. The shallow water anchor can incorporate a controller which monitors a current limit, a pressure limit, or both to perform a variety of anchoring functions.

Abstract: The present invention relates to an evacuation system for positioning and maintaining a position of an inflatable floatable unit in relation to a maritime structure during evacuation of persons at sea, comprising a maritime structure from which persons are to be evacuated, an inflatable floatable unit configured to be deployed from the maritime structure, and a bowsing system comprising a first bowsing line extending from the maritime structure to the inflatable floatable unit, and a first bowsing winch configured to, by means of the first bowsing line, bowse and position the inflatable floatable unit in relation to the maritime structure after it has been deployed from the maritime structure into the water, wherein the bowsing system further comprises a first hydraulic cylinder having a piston with a first piston end extending outside the first hydraulic cylinder, and a first hydraulic accumulator which is in fluid communication with the first hydraulic cylinder, the first piston end being connected with the

Abstract: The present invention relates to a liquefied gas carrier having a width of less than 32.3 m to pass through the old Panama Canal, which includes a liquefied gas tank having a liquefied gas storage capacity of 70K or more, preferably 78.7K.

Abstract: A pleasure boat with a system for launching/hauling a water craft is provided. The system includes a platform movable from a first position, in which it is substantially flush with the floor of the parking area of the boat, to a second position, in which it is below the water surface. The system also includes a cradle for the water craft, a guiding system for the cradle which comprises first guides extending in the parking area and second guides extending on the platform, and a handling system. The handling system includes a first handling assembly, arranged in the parking area to move the cradle along the first guides, and a second handling assembly, arranged in the platform to move the cradle along the second guides. The system allows the water craft to be automatically transferred from the parking area to the platform, and vice versa, with no manual intervention.

Abstract: A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

Abstract: Apparatus, systems and methods for collecting debris from a body of water on a vessel include at least one inflow regulator (IFR) configured to be selectively actuated to adjust the height of at least a portion thereof relative to the surface of liquid in the vessel during debris collection operations.

Abstract: A method and apparatus for producing electricity from a combination of three sources: ocean waves, wind and solar, includes converting an upward and downward motion of a buoyant platform into a rotational motion of a shaft using a plurality of blades mounted to the shaft, the blades causing the shaft to rotate from internal wind energy as the blades move up and down within a cavity. The shaft is coupled to a generator for producing electricity. A wind turbine is mounted to the buoyant platform for converting wind energy into electricity. Further, solar panels are included, for example, mounted to the buoyant platform and/or turbine blades of the wind turbine, the solar panels also generate electricity when exposed to light.

Abstract: The invention relates to a water sports device comprising an inflatable body component (1) having a longitudinal direction (L) and inflatable arms (8a, 8b) on a rear end, the arms being distanced from one another and orientated in the longitudinal direction (L), between which arms a receptacle (2) having an inner contour is formed, and comprising a drive component (7) having a tread surface (4) and an underwater surface (3), which drive component is formed with a complimentary contour (10a, 10b, 11) on two longitudinal sides (10a, 10b) that are distanced from one another and which component can be inserted into the receptacle (2) from the rear end, wherein the inner contour and the complimentary outer contour (10a, 10b, 11) form a connection to one another and a position of the inserted drive component (7) in the receptacle (2) is secured in the direction of the tread surface.

Abstract: A ballast and de-ballast system and method for an articulated tug barge (ATB) or integrated tug barge (ITB) are described herein. The system includes a tug ballast tank located on the tug, the tug ballast tank being configured to hold ballast water; and a barge trim tank located on the barge, the barge trim tank being configured to hold ballast water. The system further includes at least one umbilical line connecting the tug ballast tank to the barge trim tank. The system is configured to transfer ballast water between the tug ballast tank and the barge trim tank via the at least one umbilical line.

Abstract: A ship vicinity information display device is provided, which is capable of displaying a position etc. of a destination of another ship based on information of the destination obtained from the other ship, in a mode which is intuitively easy to understand. A radar indicator may include a display unit, an AIS interface, and processing circuitry. The display unit may be capable of displaying an image of a situation in the vicinity of one ship. The AIS interface may receive the information of the destination of the other ship. The processing circuitry may acquire a longitude and latitude of the destination based on the destination information of the other ship and graphically display at least one of the position of the destination of the other ship and a direction of the destination from the other ship (other-ship destination symbol), on the display unit.

Abstract: An enhanced system and various methods for remotely deploying boat fenders from a safe and convenient location. The boat fenders, which are placed along the entire periphery of the boat, may be deployed and retracted with lines attached to winches and motors. A smart phone app may be employed to remind users to deploy boat fenders upon entering known ports, and may also deploy the boat fenders automatically.

Abstract: A life ring includes a cover formed of a knitted back polyester fabric with a top vinyl coating, and a urethane foam core within the cover. The cover and the urethane foam core are formed into a ring shape. By using the noted cover material, the life ring can be manufactured without a painting step, thereby reducing manufacturing costs and improving the consistency of the finished product.

Abstract: This invention relates to a subsea Remotely Operated Vehicle (ROV) hub. In particular, the invention relates to a subsea ROV hub comprising a plurality of compartments for housing and deploying a plurality of ROVs.

Abstract: Apparatus and method for propelling a watercraft. An oar has a blade and a shaft, the blade having a front side and a back side, the shaft having a longitudinal axis. The blade includes a plurality of openings which pass from the front side to the back side of the blade. In some cases, the openings are slit shaped openings oriented substantially perpendicularly to the longitudinal axis of the shaft. In other cases, the smallest lateral dimension of each opening is 5 mm or less. The openings may influence the flow around the blade so that the blade is more efficient, and thus may produce more useful work in moving a boat than a solid blade with no openings.

Abstract: An actuating system for an actuatable door that comprises at least one latching device with a latching hook that is adapted for locking the actuatable door in a closed position, the latching hook being pivotally mounted to an associated pivot bearing and connected to a pivotable mechanical transmission element via a coupling link, which is pivotally mounted to the latching hook and to the pivotable mechanical transmission element, the pivotable mechanical transmission element being coupled to a rotatable latching shaft, wherein rotation of the rotatable latching shaft in operation results in pivoting of the pivotable mechanical transmission element and pivoting of the latching hook around the associated pivot bearing, wherein the pivotable mechanical transmission element is mounted onto the rotatable latching shaft. The invention is further related to an actuatable door having such an actuating system.

Abstract: A drone comprising a carrier structure, at least three lift propulsion rotors and a control system delivering at least one electrical power supply to at least three electric motors driving said at least three rotors, said at least three rotors being spaced apart longitudinally and transversely beside one another, wherein said drone includes a wing carrying two half-wings symmetrically about an anteroposterior plane of symmetry P of said drone, serving at least to increase the lift of said drone, each of said two half-wings including at least one movable portion suitable for moving relative to said carrier structure of said drone with at least a first degree of freedom to move in rotation about a first pivot axis parallel to a longitudinal direction X of said drone; and two first electric actuators respectively enabling each of said movable portions of one of said two half-wings.

Abstract: An aircraft encompasses a main-body, a frame-structure to support the main-body, main and auxiliary rotors provided to the frame-structure and a controller for controlling rotations of the main and auxiliary rotors. In a first mode, the controller delivers a same control signal for rotating the set of the main and auxiliary rotors, and when one of the main and auxiliary rotors becomes abnormal, the controller delivers the same control signal for compensating a decrease of the lift. In a second mode, the controller delivers a control signal only to the normal rotor for increasing the rotation of the normal rotor. Sets of the main and auxiliary rotors in divided regions adjacent to a subject divided region are rotated in a direction counter to the subject divided region. By the first and second modes, the lifts are equalized for balancing the aircraft.

Abstract: The invention relates to a propeller ring (10) of a turbomachine (1), with variable-pitch blades (P), the propeller ring (10) comprising a substantially coaxial annular body (11) with a main axis (A) and a plurality of radial housings (12) uniformly distributed around the main axis (A), each radial housing (12) being designed to receive a bearing (13) for a root (14) of a blade (P) so as to allow the variable pitch of the blade (P), the radial housings (12) having a substantially ovoid cross-section in a plane (T) tangential to the annular body (11).

Abstract: A mechanism for transitioning a tiltrotor aircraft between rotary and non rotary flight modes. The mechanism includes a gimbal lock positioned about a mast that is operable to selectively enable and disable a gimballing degree of freedom of a rotor assembly relative to the mast. A blade stop assembly, positioned about the mast, includes a plurality of arms having a radially contracted orientation and a radially extended orientation. A blade lock assembly is operably associated with each rotor blade assembly. Each blade lock assembly is operable to selectively enable and disable a folding degree of freedom and a pitching degree of freedom of the respective rotor blade assembly. A swash plate is operable to change the pitch of the rotor blade assemblies in the rotary flight mode and fold the rotor blade assemblies in the non rotary flight mode.

Abstract: An aircraft has a small high-speed propeller used during take-off, climbing and landing maneuvers, and a large collapsible or foldable propeller used for loitering. The large collapsible or foldable propeller is kept in a folded configuration during take-offs and landings to minimize drag and to avoid ground strikes. During loitering operations, the large collapsible propeller is unfolded and used at a lower rotational speed than the smaller high-speed propeller to permit efficient and quite loitering. During loitering operations, the smaller high-speed propeller may be disengaged so as to spin freely or held in a non-rotational position. One or more foldable propellers may be paired with at least one conventional propeller. The propellers may be arranged as twin tractor, tractor-pusher, or nearly any other type of layout on the fuselage or wings, or on pods of the fuselage or wings.

Abstract: Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Systems, methods, and apparatus may actively adjust the position and/or configuration of one or more propeller blades of a propulsion mechanism to generate different sounds and/or lifting forces from the propulsion mechanism.