Patent ID: 7316293

Claim:
An extension ladder with improved mechanism comprising: a plurality of ladder sections, connection kits, a locking mechanism, and transverse step beams, wherein each ladder section is a hollow rail having different caliber, which can be interconnected by telescoping with each other; its upper end is horizontally provided with a connection kit, while an inside of said connection kit is provided with said locking mechanism covered by said transverse step beam; Wherein said locking mechanism includes a locking bar which passes through said ladder section, on the locking bar, there are a pair of mounting grooves forming sectional axes; one of said mounting grooves is engaged by a pair of separate arms of a turning key, the other of said of mounting grooves are engaged by a pair of separate feet of a passive key, while one end of said turning key and passive key has respectively a pair of locking pawl extending outwardly from side surfaces of said turning key and passive key, such that when said locking bar moves to and fro, said turning key and passive key then rotates by using said locking pawl as axial center, one end of said passive key is installed with a pushing plate, when said locking bar moves out of said ladder section, said pushing plate then extends outward to push said turning key inside said upper connection kit and then the locking mechanism becomes unlocked.