Hydraulic prop for mines - has vertically pivoting arm for supporting roof plate universally mounted on floor base

摘要

Hydraulic prop for use in mines consists of a base resting on the floor and pivotally supporting one end of an arm. The arm position is adjustable in vertical plane by hydraulic cylinders and at the free end of the arm is pivotably mounted a head plate for supporting the roof. The head frame and the arm are comparatively wide and the arm which is vertically adjustable by two hydraulic cylinders is so attached to the base that it can pivot in vertical plane and move across its pivoting axis. The arm position across its pivoting axis is adjusted by either one double acting hydraulic cylinder positioned between the base and one of the arm cylinders or by two opposite single acting hydraulic cylinders positioned between the base and one of the arm cylinders.