Wheels made in several sections are joined with a pin and socked clamped with 2 hex set screws.
The photos show a standard pin assembly
The following drawing is not to scale.
A long joint is used to repair a broken joint in a wheel.
The dimensions of the pin are identical to a standard joint, but the ends that are welded to the rim are approximately 10 cm longer, allowing the rims to be cut a bit shorter and hence avoiding the welds of the original joint.