Patent ID: 8979421
Filing Date: 2015-03-17
Classification: B28B,B29C,E02D

Abstract:
1. A manhole cover, comprising: a base made of a composite material having 12-18 weight % of a glass fiber, 17-23 weight % of a polyester resin and a remaining weight % of CaCO3, the base being mounted in a manhole and having an exposed top; and a metallic reinforcing member which is uniformly filled in the interior so as to reinforce the base and increase the weight and strength, wherein said base contains 0.7˜1.3 weight % of a UV blocking agent to block ultraviolet rays and enhance sterilization, wherein the reinforcing member includes first to fourth elongate wires, all converging into a first point at an outer circumference of the base, the first wire extending from the first point to a second point at a first inner central circle around a central point of the base, the second wire extending from the first point to a third point at the first inner central circle, the third point being opposite to the second point, the third wire extending from the first point to a fourth point at a second inner central circle around the central point of the base, the fourth wire extending from the first point to a fifth point at the second inner central circle, the fourth point being opposite to the fifth point, the first circle having a diameter larger than a diameter of the second circle, and wherein the base has a thickness to taper in a radial direction from a central region thereof toward a circumference region thereof.