| 摘要 |
The present invention discloses a retractable ladder which is a common climbing tool in daily life and engineering industry. The retractable ladder comprises a pedal operated unlock device, section-positioning lock devices and an accidental operation preventing device. The main components of the unlock device is disposed in the first ladder section and enclosure caps at upper ends of each ladder section, except for the uppermost ladder section, are provided with the lock devices and unlock nose spikes. The retractable ladder is changed from an extended state to a folded state simply by operating the unlock device with foot of the user so as to release the lock of the ladder. Consequently, the retractable ladder will automatically retract to descend all of the ladder sections from top to bottom in turn. When the ladder is changed from the folded state to the extended state, section-positioning pins are pulled out downwardly from the uppermost ladder section so as to lock the ladder sections. The retractable ladder of the present invention is configured to extend and retract conveniently, and the use of the ladder is very easy. Further, the retractable ladder is advantageous in ease of assembling and maintenance, Meanwhile, safety is ensured so as to prevent hurts of hands of the user which may occur when a manual retractable ladder is used. In addition, the retractable ladder has advantages of low cost, safe operation and prominent improvements to the art. |
