| 摘要 |
FIELD: mining.SUBSTANCE: section of movable shield during its extraction is squeezed from its neighbouring movable shield with the help of, at least, one expansion cylinder provided in the area of shield cap piece and, at least, one directing cylinder provided in the area of shield skid. Note that expansion and directing cylinders are loaded by reduced maximum pressure discharged from high-pressure line through proper pressure control valve. Note that pressure control valve contains valve casing with high pressure inlet (P), outlet for return (R) and outlet for reduced pressure (A) of fluid medium. Note that there is a measuring piston in valve casing that is loaded by adjustable spring force and having a pass hole closed by valve needle between outlet for reduced pressure (A) of fluid medium and outlet for return (R).EFFECT: group of invention provides improved protection from neighbouring shields overturning in the course of shield section movement.10 cl, 4 dwg |
