Apparatus for production of precast manhole bases

Abstract

A system for producing precast manhole bases including an apparatus consisting of a mold jacket defining vertical walls and a mold form disposed within the jacket. The form includes the central portion spaced inwardly from the jacket and channel forming members extending over the central portion with inserts attached to the channel forming members and extending into contact with the jacket walls. When concrete is poured over the mold form and allowed to solidify, the walls of the manhole base form between the jacket walls and the mold form. The vertical walls of the base form between the jacket and the central portion, and the bottom wall of the base forms over the central portion with the channel forming members defining the channels in the bottom wall of the base. The inserts result in openings through the base walls in communication with the channels. The channel forming members consist of a first member attachable in a fixed position on the central portion, this first channel forming member being shaped for defining effluent channel and a central basin in the mold base. The channel forming members further include one or more members extending radially from the basin. These radially extending members include locking means for fixing the members in any desired position relative to the basin, and bracket means are provided for attaching the inserts to the radially extending members.