Two-stage expansion/collapse control mechanism for use on a hand-trailable luggage case

摘要

A two-stage expansion/collapse control mechanism is provided for use on a hand-trailable luggage case having an auxiliary wheel unit, which allows the auxiliary wheel unit to be expanded for use to support the luggage case when the extendable handle of the luggage case is being extended for use, and also allows the auxiliary wheel unit to be collapsed into the luggage case when the extendable handle is being pushed back into the luggage case.