A trolley wheel mechanism

摘要

A trolley wheel mechanism has two caster wheel assemblies each having a pair of wheels mounted on a rotatable housing. In a free mode the wheels are free to both rotate and to swivel. This is caused by the user pressing a release pedal. In a unidirectional mode a retainer lock engages a brake disc to prevent swivelling of the housing. This is caused by the user pressing both pedals simultaneously. A brake mode is caused by the user pressing the apply pedal.