发明名称 Extension ladder with improved mechanism
摘要 An extension ladder with improved mechanism includes a plurality of ladder sections, connection kits, locking mechanism, and transverse step portions; wherein each ladder section is a hollow rung, and the caliber of the rung becomes smaller when it is in a higher location. The upper ladder section and lower ladder section can be interconnected and fit each other; said connection kits are horizontally provided in the upper end of said ladder section. The internal part of said connection kit is provided with a locking mechanism to snap-fit into the through hole of said ladder section to secure the extension between each ladder section. The outside of said locking mechanism is covered by the transverse step portion, by the improved locking mechanism, the extension ladder can be assembled easily and firmly for providing superior safety to people, even when an external force is applied.
申请公布号 US7316293(B2) 申请公布日期 2008.01.08
申请号 US20060435135 申请日期 2006.05.17
申请人 YAO KUO-CHING;LIEFKE NORMAN WILLIAM 发明人 YAO KUO-CHING;LIEFKE NORMAN WILLIAM
分类号 E06C1/00 主分类号 E06C1/00
代理机构 代理人
主权项
地址