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A ladder leveling device having a pair of hydraulic cylinder/piston units to be secured at the outside lower ends of the ladder side rails in a manner so that the piston rods of the units extend as ladder supports. The working chambers of the units are in fluid communication with each other through

A ladder leveling device having a pair of hydraulic cylinder/piston units to be secured at the outside lower ends of the ladder side rails in a manner so that the piston rods of the units extend as ladder supports. The working chambers of the units are in fluid communication with each other through a valved passageway which, when open, allow both piston rods to adapt to an irregular supporting surface while the ladder is oriented in a vertical plane. Upon closure of the passageway to isolate the working chambers of the respective units, the piston rods act as rigid extensions of the ladder side rails. Valving of the passageway is effected by a actuating member extending between the side rails in the region of a lower ladder rung so that the member may be depressed to close the passageway by one ascending the ladder in simply stepping on the actuating member.

대표청구항 ▼

A leveling device for a ladder having a plurality of spaced rungs extending between a pair of generally parallel side rails, said device comprising: a pair of hydraulic cylinder/piston units adapted to be secured one to each of the lower ends of the ladder side rails, each of said units including an

A leveling device for a ladder having a plurality of spaced rungs extending between a pair of generally parallel side rails, said device comprising: a pair of hydraulic cylinder/piston units adapted to be secured one to each of the lower ends of the ladder side rails, each of said units including an elongated cylinder having top and bottom ends, a piston to establish a working chamber with the upper interior of said cylinder, and a piston rod connected at one end to said piston and extending through the bottom of said cylinder to a ladder support end; means for establishing a closed fluid passageway between said working chambers; valve means for, in a closed position, closing said passageway to isolate said working chambers from each other and for, in an open position, opening said passageway to place said working chambers in fluid communication with each other; and actuating means for selectively moving said valve means to said open or closed position, whereby the ladder support ends self adjust relative to the side rails when the valve means is in said open position and are fixed relative to said rails with stability in the properly oriented position, when the valve means is in the closed position, said actuating means being located in the region of a lower rung of the ladder and movable between an elevated valve-open position and a depressed valve-close position, whereby said valve means is closed by stepping on said actuating means in ascending the ladder.