Screen device for plants growing in greenhouses - contains spring loaded dilatation fittings to cancel out expansion or contraction forces exerted by greenhouse frame when screen is closed

摘要

Individual screen strips are coupled together by at least one actuator bar (4), which is used to open and close them and is preferably mounted on a roof beam in the greenhouse. Dilatation fittings (33) in the device compensate for differences in expansion between the device and greenhouse. The fittings are spring-loaded and arranged to absorb expansion forces coming from two opposite directions. Preferably transmission components (42, 43) are present to transfer expansion forces to the spring (40) in the fitting whenever it is compressed or expands. Also claimed are (i) the dilatation fittings and (ii) a greenhouse equipped with the above screen device.