| 摘要 |
PURPOSE:To provide a greenhouse ventilator assuring sheet rolling up stably through a simple mechanism. CONSTITUTION:Winding shafts 1 are nearly horizontally arranged on the ceiling valleys and side of a continuously ridged greenhouse 10, respectively, and each end of the winding shafts 1 is fitted with a winding drum 2. A rotary drum 5 consisting of a manually operating winch 6 is arranged outside the end of the ridge of the greenhouse 10. The revolution of the rotary drum 5 is transmitted to the respective winding drums 2 via a transmission wire 9 to revolve the respective winding shafts 1 and simultaneously wind or unwind the edge of a covering sheet 11. To prevent the winding shafts 1 from slipping up, a specified length of an antislip wire 3 is wrapped on each of the winding shafts 1 and stretchedly fixed in the direction opposite to that of winding up. |
