摘要:
A method and apparatus for treating preselected areas of metallic ladder rungs wherein such metallic spaced rungs are moved in a path substantially normal to the longitudinal axes of the rungs with preselected areas of the spaced rungs passing through a controlled longitudinally extending heating zone to heat such preselected areas to a desired annealing temperature.
摘要:
A method of making foldable ladder structure wherein plastic material is injected and expanded in molds to form several parts of a foldable ladder which includes front and rear ladder sections that can be pivotally hinged at their upper portions, a collapsible shelf and spreader linkage to allow the sections to be relatively pivoted from collapsed face-to-face relation to erected position.
摘要:
An improved ladder leg extender and leveler assembly including a frame structure which can be fixed in flush face-to-face relation to a ladder leg side so as to straddle rung fastener protrusions on the ladder leg side, thus avoiding bending stresses, the arrangement permitting quick and efficient assembly.
摘要:
Foldable ladder structure and method of making the same wherein plastic material is injected and expanded in molds to form several parts of a foldable ladder which includes front and rear ladder sections that can be pivotally hinged at their upper portions, a collapsible shelf and spreader linkage to allow the sections to be relatively pivoted from collapsed face-to-face relation to erected position.
摘要:
A rung lock frame and a mechanical latching structural assembly for selectively releasably locking and releasably and augmentally latching a pair of adjacently positioned rungs of relatively slidable ladder sections of an extension ladder, the rung lock frame and latching structure including guide rib and inclined ramp arrangement to permit ready movement of said latching structure into and out of augmental latching position on the rung lock frame.
摘要:
A rung lock assembly for selectively and releasably locking a pair of adjacent rungs of relatively slidable fly ladder and base ladder sections of an extensible ladder including a rung lock frame pivotally mounted within the fly ladder section to be normally urged into engagement with adjacent rungs of the ladder sections and a pulley and cable system cooperative with the rung lock frame to release and move the same away from such engagement for relative slidable movement of the ladder sections.