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Ruhrstahl AG
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Ruhrstahl AG
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Application filed by Ruhrstahl AGfiledCriticalRuhrstahl AG
Application grantedgrantedCritical
Publication of FR1076853ApublicationCriticalpatent/FR1076853A/en
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
E21D15/28—Telescopic props with parts held relatively to each other by friction or gripping
E21D15/32—Telescopic props with parts held relatively to each other by friction or gripping by a deformable collar or clamping means applied symmetrically inside a locking ring
E21D15/325—Telescopic props with parts held relatively to each other by friction or gripping by a deformable collar or clamping means applied symmetrically inside a locking ring by a clamping ring
FR1076853D1952-05-201953-05-12
Retaining post for mining especially to support the ceiling in iron mines
ExpiredFR1076853A
(en)