An apparatus for exchanging articles with an article holder includes a vertical mast having a vertical mast axis and a shuttle ring assembly. The shuttle ring assembly has a central aperture surrounding the mast and is coupled to the mast to allow the shuttle ring assembly to be translated vertically along the mast through multiple heights between a lower height and an upper height. The shuttle ring assembly includes a rotary member coupled to the mast to be rotated through multiple orientations about the mast axis. The rotary member includes multiple article-holding fixtures, angularly spaced from each other about the mast axis. The multiple orientations include a respective exchange orientation for each of the article-holding fixtures. The rotary member can be positioned in any one of the exchange orientations so that a selected one of the article-holding fixtures is in an associated exchange position. The shuttle ring assembly also includes an article transfer mechanism configured to transfer an article between the article holder and a selected one of the article-holding fixtures when the rotary member is positioned so that the selected one of the article-holding fixtures is in its associated exchange position.