| 摘要 |
328,573. Loft Ladders, Ltd., and Gorham, P. H. Jan. 29, 1929. Ladders. - The sliding portion of an extension ladder is supported on the rungs 7 of the lower portion by means of spring - actuated or counter balanced catches 6 pivotally secured to the bottom ends of the rails of the sliding portion. The catches are retained in disengageable position by means of a rope 8, so that the portions may be slid relatively to each other. |
