Abstract: A retractable roof structure has a pair of longitudinally spaced supports, guide wires extending between said supports and positioned to support a covering in a required profile. The covering comprises a plurality of sections arranged in seriatim along the guide wires with each section slidably supported on the guide wires so as to be moveable between an open position in which the area beneath the covering is exposed and a closed position in which the area beneath the covering is covered. A drive member extends between the supports and is connected to one end of each of the sections at a first location to move the one end along the guide wires. A tensile member, such as a rope or cable, extends from the peak of the leading edge of one section to the lower corner of the leading edge of a section along a path so that movement of the peak is transmitted by the tensile member to the eaves to move the section along the eave guide wire in the same direction.

Abstract: A retractable roof structure for crop protection includes pitched sections of roof defined by a retractable membrane. The membrane is moved by cables connected to a drive tube with a spring to regulate minimum tension of the cable. The drive system ensures that the membrane adjacent to the drive tube is able to travel the same distance as the second membrane from the drive tube. The rafter contains profiles to allow the stationary end of said membrane to be attached continuously to the rafters to provide a water tight connection. The rafter also contains clips which inhibit vertical, lateral and horizontal movement of the guide wires used to suspend the membrane. The guide wires are supported by flexible cables or nodes. A secondary clear membrane is installed below a white upper retractable membrane.

Abstract: A retractable roof structure for crop protection includes pitch sections of roof defined by a retractable membrane. The membrane is moved by cables connected to a drive tube with a spring regulate minimum tension of the cable. The drive system ensures that the membrane adjacent to the drive tube is able to travel the same distance as the second membrane from the drive tube. The rafter contains profiles to allow the stationary end of said membrane to be attached continuously to the rafters to provide a water tight connection. The rafter also contains clips which inhibit vertical, lateral and horizontal movement of the guide wires used to suspend the membrane. The guide wires are supported by flexible cables or rods. A secondary clear membrane is installed below a white upper retractable membrane.