Folding collapsible kick scooter

Claim 1

A folding collapsible kick scooter comprising a front wheel, a rear wheel, a handlebar and front fork assembly supported on said front wheel, a base frame, said base frame having two arched upright lugs at a front side thereof and a rear side supported on said rear wheel, said arched upright lugs each having an arched slot, a connecting bar, said connecting bar having a front end fixedly connected to said handlebar and front fork assembly and a rear end pivotally connected between the two arched upright lugs at said base frame by a pivot for enabling said handlebar and front fork assembly to be turned with said connecting bar relative to said base frame between an extended position and a collapsed position, and a quick-release lock installed in the lugs at said base frame and the rear end of said connecting bar and controlled to lock said handlebar and front fork assembly and said connecting bar, said quick-release lock comprised of a locking lever, a holding-down block a shaft, and a cap nut, said shaft having one end inserted through a through hole on said holding-down block and pivotally connected to said locking lever by pivot means, and an opposite end threaded and inserted through the arched slot on each lug at said base frame and a through hole on said connecting bar and then screwed up with said cap nut, wherein: the rear end of said shaft is a flat end of oblong cross section, having two opposite flat side walls, the through hole of said holding-down block is an oblong through hole fitting the cross section of the rear end of said shaft; said connecting bar is a tubular member holding a torisonal spring on the inside around said shaft, said torsional spring having a first end fastened to the flat rear end of said shaft and a second end secured to the peripheral wall of said connecting bar; the arched slot on each lug of said base frame has two expanded ends, the expanded ends of the arched slot on one lug of said base frame each having two vertically spaced protruded portions for engagement with the two opposite flat side walls of the rear end of said shaft upon a 90° rotary motion of said shaft with said locking lever after the rear end of said shaft has been moved to the expanded end at one end of the arched slot on one lug of said base frame.