Patent ID: 7237981

Claim:
A thermoplastic end cap, for an arch shape cross section storm water chamber having an interior cavity for receiving storm water, the chamber having an arch-end for receiving an end cap, and an open bottom and perforated sidewall for enabling outward flow of storm water introduced into the interior cavity during use, which comprises: a dome portion, for closing off said arch-end of a chamber for preventing the entry of gravel or other particulate material which surrounds a storm water chamber during use into said interior cavity, the dome portion presenting a convex exterior surface when the cap is attached to said arch-end of said chamber; a flange portion, running along an arc path around the periphery of said dome portion, for attaching the end cap to said arch-end of a chamber; and, a pipe stub, having a first end extending into said interior cavity and having an exterior surface which is smooth, substantially constant in diameter along its length and free of corrugations, which first end is integrally attached to the dome portion by plastic weld material; the stub having a second end which cantilevers outwardly from the convex exterior surface of the dome portion, for carrying water to or from said interior cavity of said chamber when the end cap is attached to the arch-end of said chamber.