Abstract: A rotary coupling for conducting rotational movement across a plurality of electrical wires is disclosed herein which applies a minimum amount of stress on the wires. The coupling generally comprises first and second concentrically disposed tubular members rotatably movable with respect to one another and a skirt member circumscribing one of the tubular members which defines a recess for receiving U-shaped slack portions present in each of the wires. In operation, the U-shaped slack portions extend into and retract out of the recess whenever the coupling members are rotated relative to one another. The rotary coupling effectively transmits torque and high electrical currents in environments where the use of slip rings is undesirable, such as outer space, and is particularly useful within a movable support arm which connects a solar panel to the main body of a space facility.

Abstract: A device for electrically connecting first and second members movable relative to each other, includes a flexible printed circuit board located between the first and second relatively movable members. The flexible printed circuit board has a first side piece and second side piece divided by a cutout made in the flexible printed circuit board. One of the first and second side pieces is bent about 180.degree. in the direction of the relative movement of the first and second members to form a turned "U" shaped portion. The first side piece has its free end portion fixed to the first member and the second side piece has its free end portion fixed to the second member, so that the displacement of the printed circuit board resulting from the relative movement of the first and second members is absorbed by movement of the "U" shaped portion.