| 摘要 |
<p>A mechanism for covering and uncovering a cold frame includes a starting base and a spaced-apart terminal base, a frame, and a cover deployable over the frame starting at the starting base and ending at the terminal base. The cover is wrapped from its midline around a cover shaft rotated by a first drive motor, as cables, attached to the leading edge of the cover, pull it over the frame. Those cables are simultaneously winding themselves around a cable shaft rotated by a second drive motor so that cover remains tight between the cable shaft and the cover shaft. The other end of the cables is secured to the starting base while the trailing edge of the cover is secured to the terminal base. Torque arms extend from the first and second drive motors and their distal ends are pivotally connected.</p> |
