Patent attributes
A drone (2) has an upper coupler (6) that releasably connects to a lower coupler (8) of a second drone (4), interconnecting the drones in a stacked combined flying machine (5A). The couplers index a predetermined rotational relationship between the two drones about a central vertical axis (10). An embodiment (5C) provides coaxial counter-rotating propellers of the respective upper and lower drones. Other embodiments rotationally offset the upper and lower drones to minimize overlap (A1, A2) of the upper and lower propeller disks or to overlap only portions (A1) of the propeller disks that rotate in opposite directions. The couplers may have electrical connectors that integrate control systems (38, 40) that establish a master/slave control relationship.
