| 摘要 |
An opening and closing device is designed to pull a pair of roof covers of straw mats (23) up and down along the inner and outer arch walls of a dual greenhouse which is formed in an inner tunnel (1) and an outer tunnel (2) at some distance each other. The device comprises an inner shaft (6), an outer shaft (7) a number of rope systems arranged at an equal interval, a chain and sprocket system (11, 12, 13) driving the outer shaft, an electric motor whose shaft is coincident with the inner shaft at its end, and a shaft coupling means (15) with a release spoke (16). A lot of bearing metals (4, 5) for the inner (6) and outer shaft (7) are mounted inside and outside the top of the arch frame at a regular interval, resp. The rope system comprises a lot of rope winders (18, 19) fixed on the shafts at a regular interval, a lot of guide rollers (22, 25) arranged in the same interval with the rope winders, and a pair of ropes (20, 20') hung at the left and right sides of the tunnel roof, whose ends are fixed to a reinforming bar (21a) provided at the top brim of the straw mat whose opposite brim is located on the ground.
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