Concrete pipe making machine with redensification apparatus

In a machine for the "dry mix" packerhead manufacture of concrete pipe comprising at least one separable upright and vertically open tubular jacket for the formation of pipe therewith, a rotatable cylindrical packerhead having an external diameter substantially less than the internal diameter of said jacket, said packerhead being axially aligned with and movable vertically within and above said pipe jacket, "dry mix" delivery means disposed above and operatively associated with said packerhead for progressively depositing the mix atop the packerhead with the packerhead rotating and moving vertically upwardly within the jacket whereby to distribute the mix radially outwardly from the packerhead and to form a concrete pipe in the annular space between the jacket and the periphery of the packerhead;

• the improvement comprising a core operatively associated with said jacket and being approximately as long as the jacket and having an external diameter approximating the internal diameter of a pipe formed within said jacket, said core being of a tubular construction and adpated for radial expansion and contraction, radially expandable and contractable connecting and supporting means for said core, first and second power operated means operatively associated with said connecting and supporting means respectively for moving the core vertically between first and second positions relative to a jacket and formed pipe and for radially expanding and contracting the core, the first position being vertically displaced from the jacket and pipe and the second position being within and concentric with the pipe and jacket, said second power operated means serving also to contract the core during movement relative to the jacket and pipe and to expand the core into firm engagement with the internal diameter of the pipe when the core is in its said second position, and at least one vibratory operatively associated with the core for vibrating the same in its said expanded second position whereby to compact the pipe, to eliminate voids, and to relieve forming stresses therein.

In a machine for the "dry mix" packerhead manufacture of concrete pipe comprising at least one separable upright and vertically open tubular jacket for the formation of pipe therewithin, a rotatable cylindrical packerhead having an external diameter substantially less than the internal diameter of said jacket, said packerhead being axially aligned with and movable vertically within and above said pipe jacket, "dry mix" delivery means disposed above and operatively associated with said packerhead for progressively depositing the mix atop the packerhead with the packerhead rotating and moving vertically upwardly within the jacket whereby to distribute the mix radially outwardly from the packerhead and to form a concrete pipe in the annular space between the jacket and the periphery of the packerhead;

• the improvement comprising a core operatively associated with said jacket and being approximately as long as the jacket and having an external diameter approximating the internal diameter of a pipe formed within said jacket, said core being of a tubular construction and adapted for radial expansion and contraction, radially expandable and contractable connecting and supporting means for said core, power operated means operatively associated with said connecting and supporting means for expanding and contracting said core and for moving the core vertically between first and second positions relative to a jacket and formed pipe, the first position being vertically aligned with but displaced from the jacket and pipe and the second position being within and concentric with the pipe and jacket, said power operated means serving also to contract the core during movement relative to the jacket and pipe and to expand the core into firm engagement with the internal diameter of the pipe when the core is in its said second position, and said core connecting and supporting means serving further as a part of said power operated means for core expansion and contraction in the second position of the core, said connecting and supporting means including at least two radially inwardly and outwardly movable members, each of said members at outer end portions urging the core radially outwardly on radial outward movement, and each of said members having inner end portions power driven at least in its radial outward direction of movement, and at least one vibrator operatively associated with the core for vibrating the same in its said expanded second position whereby to compact the pipe, to eliminate voids, and to relieve forming stresses therein.