Patent ID: 7104203

Claim:
A height adjustable tube assembly comprising: an inner tube ( 10 ); an outer tube ( 20 ) in which the inner tube ( 10 ) is retractably inserted; a height adjustable device ( 30 ) received in the inner tube ( 10 ) and including a base ( 31 ) which is fixed in the inner tube ( 10 ) and two grooves ( 310 , 311 ) defined in the base ( 31 ), two stop plates ( 32 , 33 ) respectively received in the two grooves ( 310 , 311 ) and two respective first ends ( 320 , 330 ) of the two stop plates ( 32 , 33 ) extending through apertures ( 11 ) defined through the inner tube ( 10 ) and being in contact with two respective insides of the outer tube ( 20 ), a movable member ( 34 ) movably connected to the base ( 31 ) and including a driving portion ( 340 ) which pivots two respective second ends ( 321 , 331 ) of the two stop plates ( 32 , 33 ), a cable ( 35 ) having a first end ( 351 ) thereof fixed to a first end ( 343 ) of the movable member ( 34 ) so as to pull the movable member ( 34 ) in a direction away from the outer tube ( 20 ), a resilient member ( 36 ) connected between a second end ( 344 ) of the movable member ( 34 ) and the base ( 31 ) so as to pull the movable member ( 34 ) in a direction toward the outer tube ( 20 ).