US Patent 7231689 Adjustable wheel assembly

An improved wheel assembly comprises a caster swivel post that is adapted to pivot about a pivot axis transverse to the caster swivel post. A caster fork is supported for rotation relative to the caster swivel post and rotatably supports a caster wheel. The caster swivel post is adapted selectively pivot about the pivot axis that is transverse to the caster swivel post or be held in a substantially fixed position. A setscrew can be threadable into an upper end of a pivot nut to hold the pivot nut and thus the caster swivel post in a fixed position within the housing.