Mechanism for spreading plastic sheet over greenhouse comprises bars attached to ends of sheet, one rotating and one fixed, rotating bar being driven by motor operating system of pulleys and cables to raise and lower sheet

摘要

The mechanism for spreading plastic sheet over a greenhouse comprises bars (5, 6) attached to either end of the sheet. One of these can rotate while the other is fixed. The rotating bar is driven by a motor (7) which operates a system of pulleys and cables (9, 10, 19) to raise and lower the sheet.