HYDRAULIC DOUBLE-ACTING LEG OF EQUAL RESISTING Russian patent published in 2008 - IPC E21D15/44 

FIELD: mining engineering.

SUBSTANCE: leg includes cylinder with inlets in piston and rod sides, first stage plunger, located in the cylinder, with piston and fitted with piston rod of second stage acting installed in plunger. At that head end of second stage rod is jointed with head end of first stage plunger. Besides head end of second stage rod is jointed with its rod end. Such leg accomplishment allows receiving isolated head ends with autonomous incremental lines, proved controlling of current carrying capacity during exploitation.

EFFECT: simplification of construction and leg producing technology, in particular lowering surface finishing of the second stage acting leg.

2 cl, 1 dwg