A joint assembly of an adapter defines a first longitudinal axis and includesfirstand second hinges, first and second rings, a joint cover, and a biasingmechanism. Thejoint cover has first and second cover portions. The first ring is pivotallycoupled to thefirst hinge and the first cover portion is pivotally coupled to the firsthinge to define afirst joint center. The second ring is pivotally coupled to the second coverportion andthe second hinge is pivotally coupled to the second ring to define a secondjoint centerthat is spaced from the first joint center. The first and second joint centersdefine a coveraxis of the joint cover. The biasing mechanism is engaged with the first ringand the jointcover to bias the joint cover towards an aligned configuration in which thecover axis isaligned with the first longitudinal axis.
