| 摘要 |
A pavement marker comprises an unpotted upper shell (12) and a lower base plate (14) together defining a housing, and a plurality of ribs in the housing interior oriented substantially perpendicular to the inner wall of the base plate. The upper shell has first and second opposed end faces (12B,c) inclined at an angle of approximately 30 degree , first and second opposed convex side faces (12D,E) having opposed recessed finger grip slots (30a,B) formed therein, and an upper face (12F), and is made of a plastic material having moderate to high flexural and impact moduli. The upper shell has a low profile and curved edges to minimize vehicle impact, and preferably is made of a thermoplastic resin such as polycarbonate, and includes about 30 percent glass fiber reinforcement. The lower base plate has a planar inner wall and an opposed planar, pavement-engaging outer wall, and is made of a plastic material, preferably plastic, having a Young's modulus of at least approximately 300,000 PSI (20.7 x 108 Pascal). The bottom peripheral surface of the shell can have a peripheral recess formed therein for receiving the base plate. The ribs are formed unitarily with the inner wall of either the upper shell or the base plate, and extend upwardly from the inner wall of the base plate to the inner wall of the shell to support the inner wall of the shell. A retroreflective lens (50, 52) is positioned on at least one of the first and second opposed side faces of the marker. The ribs can be arranged to extend longitudinally and transversely in a grid pattern; or they can be divided into a first group in which the ribs are circular in shape and concentric, and a second group in which the ribs extend radially with respect to the first group. The pavement marker preferably has a minimum apparent modulus of approximately 80,000 PSI (5.52 x 108 Pascals). |
