| 摘要 |
A roof vent system for greenhouses or buildings comprised of a flexible sheet of material permanently attached stationary to a lower member of vent frame and towed by a flexible tube to open or close to upper peak member of said vent by winch assisted tether ropes and closed at building ends of said vent by free flexible material grommeted and tensioned by tether ropes attached to building end walls, producing a continuous flexible window. Flexible torsion hoops provide a support system for flexible sheeting materials and at the same time act as retracting mechanisms as the said vent is being opened. The vent system is longitudinal and transverses a building from end to end functioning to evacuate heat, humidity or other elements. Opening the vent requires releasing the winch locked tethers so that the flexible material which is attached to a pull pipe is free to descend down the slope of the building roof. Tethers are used to pull the vent to a close at the peak while reverse tethers or a pole prop can be used to assist opening. |
