COCRETE PIPE MAKING MACHINE WITH REDENSIFICATION APPARATUS

摘要

A machine for "dry mix" packerhead concrete pipe manufacture has two stations and a separable tubular jacket movable therebetween. A rotatable cylindrical packerhead is movable axially within the jacket and a "dry mix" delivery means deposits mix atop the packerhead as it rotates and moves vertically upwardly within the jacket. The packerhead distributes the mix thereabout to form a concrete pipe in the jacket. A radially expandable and contractable core is movable axially in a contracted condition to a position within the pipe and is then expanded. Vibrators within the core are operated to "redensify" the pipe; that is, to compact the mass thereof, to eliminate voids, and to relieve residual forming stresses therein. A guide ring is employed to align the contracted core axially with the pipe during entry and further guiding and supporting devices for the core are provided. Core entry and withdrawal is power actuated as is core expansion and contraction within the pipe. Expansion and contraction devices may comprise fluid cylinders operated adjacent a single axial split line in the core or, true circle expansion and contraction means may be provided with a core having one or more axial split lines.