| 摘要 |
<p>A motorized mechanism (15) for actuating motion within a housing of a window shade arrangement having first and second window shades (5,7) for controlling the amount of light admitted through a window. The motorized mechanism (15) comprises a first rail assembly (25) movable in the housing and connected to a first end of the first window shade (5) and a first end of the second window shade (7), a second rail (45) assembly movable in the housing and connected to a second end of the second window shade (7), a second end of the first window shade (5) being fixed to the housing, said first and second window shades (5,7) being adapted to be extended and compressed relative to the window in accordance with motion within the housing of at least one of said first and second rail assemblies (25,45). A first cable (63) is looped between a motor-driven first pulley (65) and a second pulley (67) along a first path. A second cable (63a) is looped between a motor-driven third pulley (65a) and a fourth pulley (67a) along a second path. Corresponding ends at one side of said first and second rail assemblies (25,45) are in said first path, with only one of said first and second rail assemblies (25,45) being connected to the first cable (63), and corresponding ends at the other side of said first and second rail assemblies being in said second path, with only the other one of said first and second rail assemblies being connected to the second cable (63a).</p> |
