Apparatus for forming steps in manholes and the like

摘要: Method and apparatus for forming steps in manhole structures. Manhole assembly is comprised of pre-cast concrete sections. Each such section formed an appropriate mold typically inner outer shells. The shell provided with pairs openings arranged a predetermined fashion. Plastic core members are snap fittingly inserted into the resilient flanges which cooperate marginal edges each opening to retain proper position alignment. placed mold. One set cured, removed from plastic snapped free their locked remain as integral part cured section. U-shaped stepped sections force cores serve step member position.