A cable reel can improve transfer of power and data between a static frame and a cable wound around a rotatable element. The cable reel can use torsional springs to store mechanical energy and also to electrically couple the cable to a node within the static frame. This electrical coupling can be used to pass power. The cable reel can use a data transfer apparatus to transfer data between the frame and the cable. This apparatus may comprise two capacitive plates that together form a capacitor, one connected to the frame and one connected to the rotatable element. Alternatively, this apparatus may comprise an optically isolated zone in which an optical transmitter may communicate data to an optical receiver over free-space optical communications. The data can be transferred without physical contact between the frame and rotatable element, even while the rotatable element may rotate relative to the static frame.

A cable reel can improve transfer of power and data between a static frame and a cable wound around a rotatable element. The cable reel can use torsional springs to store mechanical energy and also to electrically couple the cable to a node within the static frame. This electrical coupling can be used to pass power. The cable reel can use a data transfer apparatus to transfer data between the frame and the cable. This apparatus may comprise two capacitive plates that together form a capacitor, one connected to the frame and one connected to the rotatable element. Alternatively, this apparatus may comprise an optically isolated zone in which an optical transmitter may communicate data to an optical receiver over free-space optical communications. The data can be transferred without physical contact between the frame and rotatable element, even while the rotatable element may rotate relative to the static frame.

A fish tape case is configured to house a fish tape in accordance with some example embodiments is provided. The fish tape includes a shell having a rotatable tray therein. A fish tape extends through openings in the shell and the tray. The fish tape case does not include a handle.

A device for winding up and unwinding an elongated flexible element having a free end and a spatially fixed end. The elongated flexible element is divided over its length at least into a use portion and a compensation portion, wherein the use portion has the free end and the compensation portion has the spatially fixed end. The device includes a rotatable drum configured on its circumference to wind up and unwind at least the use portion in a first winding plane, wherein the end of the compensation portion is spatially fixed relative to the drum. The elongated flexible element in the transition from the use portion to the compensation portion is fixed at a fastening point to the drum, and when the drum is rotated the compensation portion is coiled up and uncoiled in the form of at least one looped portion in a second winding plane.

A system includes a chassis having an interior containing at least one component secured to a base. A cable storage module is attached to the chassis and has a frame defining an interior space in which a cable is stored. The cable has a first end extending out of the frame for connection to the component and a second end extending out of the frame for connection to a device exterior to the chassis.

A system includes a chassis having an interior containing at least one component secured to a base. A cable storage module is attached to the chassis and has a frame defining an interior space in which a cable is stored. The cable has a first end extending out of the frame for connection to the component and a second end extending out of the frame for connection to a device exterior to the chassis.

A rotary connector device includes a first case, a second case, an electrical cable, and a stopper structure. The stopper structure includes a movable member, a rotation restricting portion, and a guide portion. The movable member is movable relative to the second case between a first radial position and a second radial position in a radial direction. The rotation restricting portion is provided at the first case and contactable with the movable member in a circumferential direction to restrict a relative rotation of the first case and the second case in a state where the movable member is at the second radial position. The guide portion is provided at the first case and contactable with the movable member to guide the movable member toward the first radial position.

A rotary connector device includes a first case, a second case, and a stopper structure. The stopper structure includes a movable member, a movement conversion portion, and a stopper. The movable member is rotatable about a rotation axis along with the second case with respect to the first case. The movable member is movable in an axial direction defined along the rotation axis with respect to the first case and the second case. The movement conversion portion is to convert a relative rotation of the first case and the second case into a movement of the movable member in the axial direction with respect to the first case and the second case. The stopper is provided on at least one of the first case and the second case. The stopper is contactable with the movable member.

An electric energy transmission tether for an airborne wind power station comprises an elastic core, a first layer of one or more electric conductors helically wound around the elastic core, an electric insulation layer surrounding the first layer of electric conductors, a second layer of one or more electric conductors helically wound around the electric insulation layer, and a load bearing layer surrounding the second layer of electric conductors, for absorbing tensile forces and radial pressure forces acting on the tether.

An electric energy transmission tether for an airborne wind power station comprises an elastic core, a first layer of one or more electric conductors helically wound around the elastic core, an electric insulation layer surrounding the first layer of electric conductors, a second layer of one or more electric conductors helically wound around the electric insulation layer, and a load bearing layer surrounding the second layer of electric conductors, for absorbing tensile forces and radial pressure forces acting on the tether.