Improvements in Mining Props.

摘要

16,735. Deutsch, W. July 20. Mine props. - Telescopic mine props in which the upper members are supported by filling- material are provided with movable bases d, g, k supporting the filling - material, and retained in position by screws or the like f, c, l. The base d is mounted on a plate c secured over an opening in the lower member of the prop. The base g is engaged by a plate h, mounted on a plate c and adjusted by the screw i. The base k is provided with tapering grooves m into which the screw engages.