Abstract: A jack for installing a mine stopping panel includes an extendible post and a press for extending the extendible post. The press can have a lever movable between an actuated position and a non-actuated position and operative to extend the post as it moves toward the actuated position and retract the post as it moves toward the non-actuated position. A yieldable biaser yields when the post is extended to extend the mine stopping panel and the mine stopping panel engages a mine surface with sufficient force to crush a stopping seal and anchor the stopping panel. The press can comprise an over-center toggle linkage.

Abstract: A locking device installed in a cargo support to lock a retractable tube, including a holder frame fastened to the outer tube of the retractable tube, a rack moved in a longitudinal sliding way defined between two parallel lugs of the holder frame, a driving lever pivoted to the holder frame for moving the rack, and a locking block pivoted to the holder frame and retained by a spring to lock the driving lever, wherein a L-shaped locating plate is mounted in the holder frame for the positioning of the outer tube of the retractable tube, having a round hole on a transverse section thereof through which the inner tube is inserted into the outer tube, two stop flanges bilaterally extended from a longitudinal section thereof and respectively engaged with respective end notches on the holder frame, and a lug extended from one stop flange and fastened to a lug at the holder frame; the holder frame and the locking block are respectively made of iron.