| 摘要 |
A system for fixing plastic sheets for covering greenhouses with metal or plastic clamping butterflies which are accompanied by protective washers of durable plastic and hold a specially shaped fixing component together with the plastic sheet. The metal or plastic butterflies have a wedge-like ending A, a step shaped neck B and wings without points C. They are installed by hand, secured by turning through 90 degree and can be used any number of times. The washers of durable plastic protect the frame and the metal components. The fixing component is fitted to the frame and holds and protects the plastic sheet which may be of any thickness. The fixing component is specially shaped to fit the frame of the greenhouse well. The system is used in greenhouses of semi-metallic construction with a frame of tubes of any diameter or of metal rods of rectangular cross-section with a long length. |
