| 摘要 |
PURPOSE:To enable a damper to open and close very easily by utilizing the water pressure of city water, by constituting the damper in such a manner that it can be opened by a flexible expansion tube, which is contracted when the damper is closed, being expanded by feeding of water. CONSTITUTION:A thermally controlled three-way cock C is installed in a greenhouse A, and a city water feed pipe 5, a discharge pipe 6 and an operating water pipe 7 are connected to the cock C. The operating water pipe 7 is connected to one end of a flexible expansion tube 2. The other end of a tube 2 is closed. Prior to use, the tension of a temperature controlling spring 13 is adjusted by turning a controlling screw bolt 11 to set the temperature to drive a damper, that is a window 1, to open. When the temperature in the greenhouse A rises and it reaches a set temperature, the free end 10a of an operating plate 10 pushes up a valve stem 15 against the tension of a spring 17 and a valve body V1 comes away from a valve seat 20. Then city water is fed from an operating water intake 14c into the flexible expansion tube 2 through the operating water pipe 7 to make the flexible expansion tube 7 expanded, and the window 1 can be opened by its expansion. |
