| 摘要 |
<p>A mine roof support comprises a plurality of hydraulically extensible chock legs 5,6, articulated at upper ends thereof to one or more roof beams 3 and at lower ends thereof to one or more base members 1, a shield 9 pivotally connected to a rearward part of the base member 1 and also pivotally connected to a rearward part of the roof beam 3, with permanently pressurised rams 12 both located between a pair of laterally spaced chock legs 6 and one located to each side of the centre line 19 of the support, the rams being mutually inclined with respect to the centre line 19 and reacting via the shield 9 on the roof beam 3, and a pair of tie bars 11 located one at or towards each side of the support and both connected between the roof beam 3 and the shield 9.</p> |
