| 摘要 |
Parabolic reflector includes a number of sectors ( 2 ) being connected to each other at a central hub ( 3 ), the parabolic reflector being collapsible from an extended position ( 9 ), in which the sectors together extend 360 °around the hub ( 3 ), to a retracted position ( 8 ), in which the sectors ( 2 ) are brought together into a compact unit. Each sector ( 2 ) is rigid and is firmly joined to a cylindrical hub sleeve ( 4 ). The hub sleeves ( 4 ) together form the hub ( 3 ), around which the sectors ( 2 ) are journalled for limited movement around a central axis extending through the center of the hub ( 3 ). The hub sleeves ( 4 ) are concentrically arranged one radially inside the other with consecutively decreasing radii, and the hub sleeves ( 4 ) have mutually cooperating guiding surfaces that permit axial displacement of the hub so as to enable relative rotation there between.
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