| 摘要 |
Roll-forming apparatus and method for more precisely shaping an extruded-plastic Fresnel lens. A drive/support roller is rotatably mounted to the support frame and the surface of which engages and rotates to support the smooth outer surface of an extruded arcuate, elongated linear Fresnel lens. A tooth-forming roller is rotatably mounted to the support frame and has an external profile with tooth-forming projections formed thereon for engagement with the grooves on the inner surface of the extruded sheet, said tooth-forming roller being positioned on the inner surface of the Fresnel lens opposite the drive/support roller and being loosely mounted on the support frame to track the grooves formed in the Fresnel lens to improve the profile of the lens section by sharpening the root radius and flattening the optical face of each lens section. The tooth-forming roller is rotatably mounted to a biased floating yoke assembly for rotation of the tooth-forming roller about an axis perpendicular to the longitudinal direction of the movement of the arcuate, elongated linear Fresnel lens and wherein the yoke assembly provides for movement of the tooth forming roller about a longitudinal axis which is aligned in the longitudinal direction of the movement of the arcuate, elongated linear Fresnel lens. A pressure piston applies force to the yoke frame through the second ball-and-socket joint member. The tooth-forming roller is formed as two separate independent roller segments which are mounted coaxially for separate side-by-side movement. To cover the entire width of the lens, rows of tooth-forming rollers and corresponding drive/support rollers are provided.
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