| 摘要 |
A roof ladder construction includes a roof hook assembly and a ladder to which the roof hook assembly is pivotally mountable for movement between two operative positions, a first of the operative positions being a position in which the roof hook assembly may extend over a roof ridge for engagement with a remote roof surface at a side of the roof opposite that at which the ladder is positioned and the other, second position being one in which the roof hook assembly does not engage with the remote surface of the roof. |
