E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
E21D15/00—Props; Chocks, e.g. made of flexible containers filled with backfilling material
E21D15/14—Telescopic props
E21D15/16—Telescopic props with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure
E21D15/20—Telescopic props with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure with pawl, pin, cross-piece, or the like engaging with ratchet teeth, notches, holes, or the like, spaced apart at intervals
Vorrichtung zum sichern eines schiebers eines presswerkzeugs, der zwischen einer zurückgesetzten position und einer arbeitsposition beweglich montiert ist