A system, method and apparatus for unfolding and folding a multi-arm device that includes a support member and an actuator. A first arm is coupled to the actuator and extends from a folded position to an unfolded position upon actuation of the actuator. A second arm is coupled to the actuator and moves from a folded position to an unfolded position upon actuation of a linkage that causes the second arm to rotate. A third arm moves from a folded position to an unfolded position, via an elbow joint, upon release of a tether attached to the third arm.

A system, method and apparatus for unfolding and folding a multi-arm device that includes a support member and an actuator. A first arm is coupled to the actuator and extends from a folded position to an unfolded position upon actuation of the actuator. A second arm is coupled to the actuator and moves from a folded position to an unfolded position upon actuation of a linkage that causes the second arm to rotate. A third arm moves from a folded position to an unfolded position, via an elbow joint, upon release of a tether attached to the third arm.

The present disclosure provides a deployment mechanism for arms of a drone. This mechanism is particularly of relevance to a drone that is housed in a container and is configured to be launched therefrom, and therefore is required to have an efficient deployment mechanism for its arms to be deployed immediately after the launch. The deployment mechanism is biased to its deployed state and is retained in its non-deployed state by external forces, such as the normal forces that are applied by the walls of the container on the arms while the drone is housed within the container. After the launch from the container, the above-mentioned forces are no longer applied to the arms of the drone and the deployment mechanism, causing a transition of the arms from their non-deployed state to their deployed state, in which they are in a position suitable for flying, i.e. activation of the rotors mounted on the arms.

The present disclosure provides a deployment mechanism for arms of a drone. This mechanism is particularly of relevance to a drone that is housed in a container and is configured to be launched therefrom, and therefore is required to have an efficient deployment mechanism for its arms to be deployed immediately after the launch. The deployment mechanism is biased to its deployed state and is retained in its non-deployed state by external forces, such as the normal forces that are applied by the walls of the container on the arms while the drone is housed within the container. After the launch from the container, the above-mentioned forces are no longer applied to the arms of the drone and the deployment mechanism, causing a transition of the arms from their non-deployed state to their deployed state, in which they are in a position suitable for flying, i.e. activation of the rotors mounted on the arms.

A tension-torsion strap includes a first spindle and a second spindle, which are spaced apart from each other, such that the first and second spindles are positioned at opposite ends of the tension-torsion strap, a winding formed of a filament wrapped about the first and second spindles a plurality of turns, the winding extending between and connecting the first and second spindles and being positioned within a cavity formed circumferentially about each of the first and second spindles, and a protective layer covering the winding, which is formed according to an arched winding pattern, a portion of the winding extending outside boundaries of the cavity defined by the inner wall and the lateral walls, such that an outer surface of the winding has an arched, or curved, profile.

A tension-torsion strap includes a first spindle and a second spindle, which are spaced apart from each other, such that the first and second spindles are positioned at opposite ends of the tension-torsion strap, a winding formed of a filament wrapped about the first and second spindles a plurality of turns, the winding extending between and connecting the first and second spindles and being positioned within a cavity formed circumferentially about each of the first and second spindles, and a protective layer covering the winding, which is formed according to an arched winding pattern, a portion of the winding extending outside boundaries of the cavity defined by the inner wall and the lateral walls, such that an outer surface of the winding has an arched, or curved, profile.

An extension assembly for a rotor system for rotating a plurality of rotor blades about a rotor axis with a central rotor hub that defines the rotor axis includes a beam assembly and a first bearing assembly. The beam assembly is configured to attach to the central rotor hub and is positioned at least partially within a corresponding one of the plurality of rotor blades. The first bearing assembly is configured to be fastened to the beam assembly and to at least one of a leading edge or a trailing edge of the corresponding one of the plurality of rotor blades.

A rotor blade assembly connectable to a rotor hub configured to rotate about a center axis includes a torsional pitch member coupled to the rotor hub, a torque tube coupled to the torsional pitch member, wherein the torsional pitch member extends away from the center axis through a portion of the torque tube, a blade coupled to the torque tube, and a pitch control member coupled to the torque tube and configured to control a pitch angle of the blade, wherein the torsional pitch member includes a first curvilinear channel and a second curvilinear channel each having a front side and a back side, wherein the first curvilinear channel and the second curvilinear channel are disposed adjacent to each other, such that the back side of the first curvilinear channel faces the back side of the second curvilinear channel.

A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.

A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.