You can buy all sorts of fancy gizmos if you have a collection of old-fashioned, automatic, mechanical watches that you want to keep wound when they aren’t on your wrist.
Today’s invention is a new, somewhat humorous variant.
It consists of a mainspring and escapement attached to a pendulum (exactly as used to control grandfather clocks). The pendulum in this case consists of one or more watches, so that not only are they kept wound by the mechanism, the whole system allows the owner to read the time via the watch face(s).
Since the period of oscillation (for small angles) is independent of the mass, a small collection of such watches could be arranged to form the pendulum.
Periodically of course, the mainspring will need to be would up tight.