Hydraulic rock breaking tool

摘要

A hydraulic rock breaking tool of modular construction comprises an assembly of shaft sections having a longitudinally extending bore therethrough and lateral passages communicating with the bore. The shaft assembly provides a number of radial abutment flanges between which a number of self-supporting, radially expansible, elastomeric membranes are confined in the longitudinal direction, each membrane having a cylindrical portion surrounding the shaft and defining with it an annular space communicating with the bore via the lateral passages. Each membrane has a pair of annular end flanges, each terminating in an axially extending retrorse flange which is seated against the shaft section for sealing engagement with it, the retrorse flanges being urged against the shaft by fluid pressure in the annular space.