Telescopic hydraulic pit prop - has cap fitting over intermediate block with rubber insert to permit eccentricity of load

摘要

A hydraulic pit prop. with an inner member sliding telescopically inside an outer member, as in the main patent, has a top cap which is mounted so as to permit a limited amount of eccentrically of the load with respect to the central axis. The cavity at the top is replaced by a joint piece (29) in the form of a plug with a groove (31) around it for a locking ring (34). An intermediate block (30) fitting onto this joint piece carries a rubber buffer (23) in which is incorporated a metal strengthening ring (26'). The buffer has a sleeve (23) through the middle which projects upwards to fit into an upper block (33). Housed inside the sleeve is a metal plug (26). Finally a cap (17) secured by another locking ring (36) fits over the shouldered top of the upper block (33). The cap has four lugs (39) on the top.