Abstract: A wheel assembly having a braking mechanism that is actuated by centrifugal force. The braking mechanism includes a rotating hub insert having a first pocket, a thread guard having a second pocket fixed relative to the frame of the wheel assembly, and an internal ball between the rotating hub insert and the thread guard. The internal ball can be flung by centrifugal force from the first rotating pocket to the second fixed pocket to cause a braking force from contact of the ball in the second pocket with the rotating hub insert. The amount of centrifugal force required to fling the ball into the second pocket can be calculated for rotation of the wheel greater than a certain predetermined speed.

Abstract: A wheel assembly includes a tubular spindle having a central portion of reduced diameter defining at each axial end of the central portion an axially facing locking surface. Two annular bearing members encircle and are supported on the spindle on opposite sides of the reduced diameter central portion, each bearing member having at least one resilient locking member which projects axially toward the other bearing member and which has a shoulder engageable with a respective shoulder on the spindle. Each bearing member has at its axially outer end a radial projection which carries an axially inwardly facing annular surface. A wheel has a central axial opening, the spindle and bearing members being disposed within the opening and the radially outer surfaces of the bearing members engaging the central axial opening through the wheel. The wheel has at each end of the central opening an axially outwardly facing surface which engages the surface on the radial projection of a respective bearing member.