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
E21D15/24—Telescopic props with parts held together by positive means, with or without relative sliding movement when the prop is subject to excessive pressure with axial screw-and-nut, rack-and-worm, or like mechanism
Landscapes
Engineering & Computer Science
(AREA)
Mining & Mineral Resources
(AREA)
Mechanical Engineering
(AREA)
Structural Engineering
(AREA)
Life Sciences & Earth Sciences
(AREA)
General Life Sciences & Earth Sciences
(AREA)
Geochemistry & Mineralogy
(AREA)
Geology
(AREA)
Hooks, Suction Cups, And Attachment By Adhesive Means
(AREA)
Cale deplaçable le long d'un profile et rabattable par pivotement contre celui-ci pour chaque pneu d'un vehicule routier porte par une unite de transport