Patent ID: 6817589
Filing Date: 2004-11-16
Classification: B28B

Abstract:
An apparatus for removing a joint ring from a concrete product such as a concrete pipe or manhole segment, which joint ring was placed during the manufacture of the concrete product to form a joint in the final product, said apparatus comprising: a puller beam assembly moveable toward and away from a concrete product positioned for joint ring removal and having pull bits independently moveable inwardly and outwardly toward and away from the joint ring to be removed as to engage the joint ring on opposite sides; first power units for moving the pull bits inwardly and outwardly; a clamping assembly have inner and outer clamps adapted to engage the concrete product and restrain the concrete product from movement during the removal of the joint ring; second power units for applying an independent tensile force to the pull bits to pull the joint ring from the concrete product; a pressure transducer for monitoring the tensile force applied to the joint ring by each pull bit; a first control responsive to the pressure transducers to maintain a predetermined initial tensile force on each pull bit; a pneumatic hammer combined with each pull bit to apply a shock force laterally to the joint ring through the pull bit; the pressure transducers being adapted to sense a drop in the tensile forces which drop indicates the joint ring is freed from the concrete product; and a second control responsive to the pressure transducers to signal the puller assembly to move away from the concrete product thereby carrying with the assembly the joint ring.