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
Boulon demontable pour assembler de facon tournante l'un a l'autre deux elements mecaniques de petites dimensions axiales, particulierement pour des systemes de leviers de machines textiles
Organe de fixation mécanique de deux éléments l'un à l'autre, notamment pour la fixation d'un carter de direction à un support de direction.