Abstract: A configuration of a multirotor aircraft that will facilitate enhanced yaw control includes one or more adjustable members that will twist the frame of the multirotor aircraft, thereby adjusting the orientation of the motors and propellers and enhancing the yaw control of the multirotor aircraft. In some implementations, the adjustable member(s) are passive and twist in response to differential thrusts generated by the propellers. In other implementations, the adjustable members are active and twist in response to a yaw command from the multirotor aircraft control system.

Abstract: An animal litter-box including granular-material-housing, having a window opening formed in the front side of the granular-material-housing, allowing an animal to walk in and out of the granular-material-housing. The window opening includes an upper edge, a lower edge and two side edges. The animal litter-box further includes a granular-sifting-apparatus, having a container body, and a litter-scooper disposed inside the upper portion of the container body. The litter-scooper includes a scooper container body, wherein sifting-openings are formed at the bottom and optionally, at the lower sides of the scooper body. The granular-sifting-apparatus further includes a paws-sifter, disposed on top of the litter-scooper, for the animal to step on when going in and out of the granular-material-housing.

Abstract: A fastener device provided with at least one movable stud and a stationary stud, the movable stud including first magnetization means co-operating with second magnetization means of the stationary stud. One magnetization means is carried by a ball joint, each magnetization means being carried by movement means in order to move the first magnetization means in translation in a plane and to move the second magnetization means in translation along a longitudinal axis that is substantially orthogonal to the plane from an engagement position to a disengagement position in reversible manner, the magnetization means being strongly magnetically attracted to each other when they are facing and each in the engagement position and being magnetically attracted only slightly or not at all when at least one magnetization means is in the disengagement position.

Abstract: A parachute device is provided with a bag containing a main parachute and a reserve parachute and with a propulsion assembly having a frame to which two arms are coupled; the two arms can be opened laterally by operating a control and support respective power units, which can be started by operating a further control.

Abstract: A system for pylon attachment for mounting an engine on a structure of an aircraft, or to wings of the aircraft, is provided. The system includes a first attachment mechanism that can be secured to the pylon and a second attachment mechanism that can be secured to the structure of the aircraft. A connection mechanism connects the first and second attachment mechanism. The connection mechanism allows movement of the first attachment mechanism in relation to the second attachment mechanism between first and second positions.

Abstract: A helicopter dolly includes a platform defining a helicopter landing area, a plurality of rollers connected to the platform such that a vertical clearance is defined between the platform and the ground and a plurality of safety panels movably connected to edges of the platform so as to be movable relative thereto between raised and lowered positions. The safety panels cover the vertical clearance in the lowered position. A method of using a helicopter dolly includes arranging a helicopter dolly for a helicopter landing, moving a plurality of safety panels and a plurality of corner members to cover a vertical clearance defined between a platform and the ground and moving the plurality of safety panels and the plurality of corner members to uncover the vertical clearance after the helicopter landing.

Abstract: Disclosed is a disc-shaped aircraft with dual spinning discs, comprising an engine, an upper fuselage, a lower fuselage, an upper spinning disc and a lower spinning disc. An upper cover is arranged at the bottom of the upper fuselage, and a lower cover is arranged at the top of the lower fuselage. The upper and lower covers are connected as a whole through an axle tube. A central gear is installed on the axle tube. The lower spinning disc is installed on the central gear and the upper spinning disc is located above the lower spinning disc. The engine is fixed on the lower cover and drive the central gear so that the upper and lower spinning discs are driven to rotate. Helical blades of the upper and lower spinning discs are opposite in rotary direction, angle of attack and installation angle, so that the problem of rotary balance of the fuselage is solved. The disc-shaped type aircraft provided by the invention is simple in structure, light in weight and low in cost, and can save much lifting power.