| 摘要 |
<p>A screening plate is movable between inner and outer positions, to the side of a cap, beyond the edge of which it protrudes in its outer position, on the striding support frame used in underground mining. The plate(27) is fitted on the underside of the surface(10) of the cap(8) fitting against the seam roof(9). It is pressure-activated towards the outer position by compressed leaf springs(20) at a set interval apart. One end(22) of these is attached to the cap and the other to the plate, and they run at an angle to the lateral cap edge. The screening plate can still move sideways when the cap is close against the roof, and effect automatic gap closure between adjacent frames.</p> |
