| 摘要 |
PURPOSE:To obtain a required strength and to facilitate manufacture by using a jointless frame for a frame supporting a rib, fitting the frame to a peripheral of the rib and to the inside and adopting the structure fitting a thin plate reflecting plate to a curved part of the rib. CONSTITUTION:The rib 2 being deeper than a conventional rib is used, the frame 3 supporting the rib 2 is the jointless frame, e.g., an angle of channel- shaped extruded member, fitted to the peripheral and inside of the rib 2 and a thin plate reflecting plate 1 is fitted to the curved part of the rib 2. A plate processed by an NC milling machine is used for the rib 2 to form a curved face with high accuracy and a thin plate 1 being a reflection plate uses a thin plate mating to the curved face of the rib 2 and fitted to the curved face of the rib 2 by using screws or rivets. |
