Abstract: A telescopic tube mounting device, which includes an outer tube having a coupling at the top, an inner tube made to slide in and out of the outer tube and locked at the desired elevation by a lock screw on the coupling, a C-shaped locating ring fastened to the bottom end of the inner tube to prohibit disconnection of the inner tube from the coupling, a stopper sealed in the bottom end of the inner tube and having a longitudinal through hole with a tapered top orifice for passing air in and out of the inner tube to buffer the falling speed of the inner tube when the inner tube is collapsed.

Abstract: A track-mounted lighting fixture including a track mounting device having a split extended from a horizontal top mounting channel to an outer thread thereof, a lock nut threaded onto the outer thread, and a connector to connect a lamp holder to the track mounting device, whereby the pitch is enlarged for allowing the track mounting device to be mounted on an overhead track as the lock nut is turned in one direct; the pitch is shortened for allowing the track mounting device to be firmly retained to the overhead track as the lock nut is turned in the reversed direction.