US Patent 6886216 Caster leg assembly with adjustment locking means

The caster leg assembly has a slidable collar mounted on a shank that is threaded onto a stud fixed within a hollow table leg. A resiliently deformable ring is positioned between a shoulder on the shank and an inwardly turned end of the leg. A locking nut is threaded onto a threaded portion of the collar to abut the inwardly turned end of the leg. After the shank has been adjusted along the length of the stud, the locking nut is threaded against the end of the leg to cause the collar to be drawn in a direction out of the leg thereby compressively deforming the ring to frictionally engage the collar and leg. This, in turn, locks the shank against rotation relative to the leg.