Abstract: A rotational coupling includes input and output hubs disposed about a rotational axis and an attachment ring disposed about the axis on one side of the input hub opposite the output hub. A flexible, multi-coil body such as a cable is disposed radially outwardly of the input and output hubs and couples the hubs together for rotation upon rotation of the input hub in one rotational direction. The body has ends coupled to the output hub and attachment ring. A torque limiter includes a torque transmission plate configured to rotate with the input hub and an armature plate fixed against rotation. The torque transmission plate and armature plate are configured to move axially together along the axis of rotation. An electromagnet disposed on one side of the torque limiter opposite the input hub attracts the plates in a second axial direction away from the attachment ring when energized.

Abstract: A rotational coupling is provided. The coupling includes first and second hubs disposed about an axis of rotation. A wrap spring is disposed radially outwardly of the hubs and rotatably couples the hubs upon rotation of the first hub in a first rotational direction. A spring actuation member is configured for rotation about the axis and coupled to one end of the wrap spring. The opposite end of the wrap spring is coupled to the second hub. An actuator is configured to selectively stop rotation of the spring actuation member and the second hub in the first rotational direction and cause rotation of the spring actuation member in a second rotational direction to thereby unwrap the wrap spring. The rotational coupling therefore facilitates disengagement of the wrap spring from the first hub during release of the coupling to prevent undue noise and vibration and reduce wear.

Abstract: A rotational coupling is provided. The coupling includes first and second hubs disposed about an axis of rotation. The coupling further includes a wrap spring engaging the first hub and disposed radially outwardly of the second hub. The wrap spring is configured to couple the first and second hubs together for rotation during rotation of the first hub in a first rotational direction. The coupling may include one or more shoes disposed radially between the second hub and the wrap spring and springs for biasing the shoes radially outwardly from the second hub. By urging the wrap spring away from the second hub, quick and complete release of the wrap spring occurs even where the difference in rotational speed between the hubs during clutch disengagement is low.

Abstract: A rotational coupling is provided. The coupling includes first and second hubs disposed about an axis of rotation. A wrap spring is disposed radially outwardly of the hubs and rotatably couples the hubs upon rotation of the first hub in a first rotational direction. A spring actuation member is configured for rotation about the axis and coupled to one end of the wrap spring. The opposite end of the wrap spring is coupled to the second hub. An actuator is configured to selectively stop rotation of the spring actuation member and the second hub in the first rotational direction and cause rotation of the spring actuation member in a second rotational direction to thereby unwrap the wrap spring. The rotational coupling therefore facilitates disengagement of the wrap spring from the first hub during release of the coupling to prevent undue noise and vibration and reduce wear.