초록 ▼

A prefabricated composite vertical earth drain which has an elongated corrugated flexible plastic core sheet with horizontal corrugations that provide continuous longitudinally extending drain channels. Desired longitudinally extending surfaces of these drain channels are provided with a series of c

A prefabricated composite vertical earth drain which has an elongated corrugated flexible plastic core sheet with horizontal corrugations that provide continuous longitudinally extending drain channels. Desired longitudinally extending surfaces of these drain channels are provided with a series of closely spaced reliefs for inhibiting tendencies of the core to horizontally bend and fold or collapse, thereby pinching off the vertical drain channels.

대표청구항 ▼

[ I claim:] [1.] A prefabricated vertical earth drain including an elongated corrugated flexible plastic core sheet having horizontal corrugations providing continuous longitudinally extending drain channels defined with longitudinal corrugation corner bends, the improvement comprising selected long

[ I claim:] [1.] A prefabricated vertical earth drain including an elongated corrugated flexible plastic core sheet having horizontal corrugations providing continuous longitudinally extending drain channels defined with longitudinal corrugation corner bends, the improvement comprising selected longitudinally extending surfaces between adjacent corner bends of said channels having a series of closely spaced reliefs confined within said selected surfaces without impinging on said corner bends for inhibiting tendencies of the corrugated core sheet to horizontally fold and thereby pinch off said vertical drain channels.