Patent ID: 7549520

Claim:
A spring structure of a multi-joint luggage pull-rod, the pull-rod comprising at least three joint tubes and a grip, said grip having a press button placed thereon, the joint tubes having a bottom with a positioning base placed thereon, said positioning base having a resilient jumping bean and resilient spring placed therein, said resilient jumping bean having an oblique surface placed on a predetermined part thereof, said positioning base having a through hole and a protruding foot placed on a top and bottom thereof respectively, said spring structure being placed inside said positioning base made by the first and second joint tubes, said spring structure comprising: a spring; and a top base, being comprised of a concave part, a protruding joint, and a spring limiting part, said concave part connecting to said protruding foot of said positioning base by the first joint tube, said protruding joint being inserted in said through hole of said positioning base made by the second joint tube, said spring limiting part being connected to a top end of said spring; and a base, being comprised of a spring support and a prop, said spring support being connected to a bottom of said spring, said prop being pushed against a top of said positioning base made by the second joint tube, said base having a yielder placed on one side of said base for said protruding joint of said top base to go through.