Adjustable seat tubing device for a bicycle

An adjustable seat tubing device for a bicycle comprising:

• a tubing assembly, an adjusting unit and a controlling assembly;
• the tubing assembly comprising an outer tubing, an inner tubing and a connecting member, the outer tubing assembled to a bicycle, the inner tubing passing through the outer tubing, the connecting member sleevingly defined between the outer tubing and the inner tubing, the connecting member having an outer connecting portion defined at an outer periphery thereof, the outer connecting portion communicating with the tubing assembly;
• the adjusting unit comprising a pivoting assembly, a driving assembly, an engaging assembly and an elastomer;
• the pivoting assembly pivotally assembled into the outer connecting portion;
• the driving assembly assembled into the tubing assembly, the driving assembly comprising a supporting member and a flapping member, the flapping member pivotally assembled into the supporting member, the flapping member having a pushing portion defined at one end thereof and a working portion defined at another end thereof, the working portion passing through the supporting member;
• the engaging assembly comprising a gear rack and an engaging block, the gear rack assembled into the inner tubing, the gear rack having a plurality of rack teeth defined at one side thereof, one side of the engaging block pivotally assembled to the supporting member, and another side of the engaging block having a plurality of engaging teeth, the engaging teeth engaging with the rack teeth of the gear rack, the pushing portion slidably assembled to the engaging block;
• the elastomer defined in the outer tubing, the elastomer enclosing the driving assembly, two ends of the elastomer abutting against the inner tubing and the outer tubing respectively;
• and
• the controlling assembly comprising a switch and an actuating member, one end of the actuating member assembled to the switch, and another end of the actuating member pivotally passing through the pivoting assembly and assembled to the working portion inside the outer tubing, the actuating member driving the pivoting assembly rotating simultaneously;
• wherein when a user presses the switch, the switch drives the actuating member firstly;
• then, the actuating member drives the flapping member;
• and then, the flapping member drives the engaging block disengaging with the gear rack;
• as a result, the inner tubing is movable relative to the outer tubing, so that a height of the tubing assembly is adjustable to the user for riding bicycle comfortably.