| 摘要 |
<p>A covering for architectural openings including a roller, a shade wrapped around the roller, the shade extendable from the roller when the roller rotates in a first direction, and retractable onto the roller when the roller rotates in a second direction. The covering also includes a retraction mechanism operably associated with the roller for biasing the roller in a direction to retract the shade and a positioning device operably engaging the roller for selectively holding the shade at a selected extension location and selectively releasing the shade for additional extension or retraction. The positioning device is actuated to hold the shade at the selected extension position by movement of the shade in either the extension or retraction direction.</p> |
