| 摘要 |
A polymeric electrical enclosure has an electrical access knockout having a plurality of concentric grooves integrally molded into a wall section of reduced thickness. A plurality of angularly spaced, frangible flow leaders all bridge the outermost groove, with a lesser number bridging the remaining concentric grooves to facilitate the flow of material during molding to the knockout segments defined by the grooves. The concentric grooves are progressively deeper from the outermost to the innermost to aid in selective removal of inner segments without fracture of the outer segments. A flow leader which bridges all the grooves becomes narrower at the inner grooves, as less material need flow through that section of the flow leader, and the narrower section fractures sooner, thus aiding in selective removal of the inner segments of the knockout. |
