| 摘要 |
1452984 Greenhouse: roof: truss VSES AKAD SELSKOKHOZYAISTVENNYKH NAUK IM V I LENINA 31 Jan 1974 4437/74 Headings E1A, E1K and E1W A greenhouse comprises a roof truss 2 mounted on support columns 1, the truss having an upper chord and two laterally spaced bottom chords, and a roof mounted on the bottom of the truss comprising a plurality of horizontal, translucent panels 3. The panels 3 are supported by framing members 12 releasably mounted on flanges 15 and are arranged in a stepped manner downwardly from the centre of the truss. Some of the panels 3 are slidable and have wheels engaging the lower flanges of I-sectioned framing members 12. They are operated by a rope and pulley arrangement. Each truss has one end fixedly mounted on a column 1 and the other end secured to a plate 7 slidable between two upstanding flanges 10 on top of another column. |
