| 摘要 |
A shield support, suitable for use in mines, comprising a floor-engaging structure, a roof-engageable canopy, extendible and contractible prop means disposed between the floor-engaging structure and the canopy, and a shield assembly pivotally-connected to the canopy at or near its rearward end portion. The shield assembly includes a lazy tongs linkage, one element of which is pivotally-connected directly to the floor-engaging structure and another element of which is pivotally-connected to the floor-engaging structure through the intermediary of a further element.
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