Abstract: A caster is provided which makes use of a wheel that has discrete notches and that is rotatably mounted to a housing, a locking pin that is movably mounted to the housing to engage (or to disengage from) any one of the notches, and an actuator for use by a user in moving the locking pin into engagement (or disengagement). The housing also has a distinct notch into which the locking pin moves when it engages any of the wheel notches, so that locking force is borne by the housing rather than by the actuator. The notches are preferably defined in an internal surface of the wheel. Advantageously two identical wheels are used in opposition, for optimum strength and appearance.

Abstract: A seat swivel apparatus includes a first mounting plate rotatively mounted to a second mounting plate. Each of the first and second mounting plates has a circular recess formed therein to define a pair of bearing races which hold bearing means such as a plurality ball bearings. The first and second mounting plates are held together utilizing fastening means that include a Belleville spring to provide a continuous and substantially constant biasing force on the plates to maintain them in proper rolling contact with the ball bearings. Each of the races include two arcuate sidewall portions and a connecting portion between the sidewall portions, the connecting portions being substantially flat to help prevent the bearings from tightening within the races.