Stairlift

A carriage for a stairlift mounted to a rail, comprising:

• a frame;
• a central drive unit mounted to the frame, the central drive unit including a drive motor and a drive gear coupled to the drive motor for rotation therewith;
• a seat mounted to the central drive unit;
• a yoke assembly pivotably mounted to the frame;
• and
• a first bogie unit attached to the yoke assembly and a second bogie unit attached to the yoke assembly, wherein each bogie unit includes a bogie socket fixedly mounted to the yoke assembly, a bogie ball pivotable within the bogie socket, the bogie socket having a wall defining a passageway having a partial spherical shape and the bogie ball having an exterior surface having a partial spherical shape, wherein the walls of the bogie socket and the bogie ball maintain contact during operation to hold the bogie ball within the bogie socket while allowing for rotation of the bogie ball in three dimensions relative to the bogie socket and the yoke assembly, and a plurality of bogie ball rollers mounted on the bogie ball and which are configured to mount the bogie ball to the rail.