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.

Abstract: A sewing machine for attaching tapes to a web includes a web feed station, a sewing station and a transfer mechanism to transfer the web from the sewing station to a collection zone. The sewing station includes a sewing head that moves across the web to sew the tape. The tape has hooks periodically spaced along the tape and movement of the sewing head is initiated by sensing one of the hooks at a predetermined locator. Successive tapes may then be sewn with the hooks aligned.

Abstract: A roof structure to protect a crop growing area includes a retractable roof membrane or curtain that defines pitched sections of the roof. The membrane extends across the valley between pitched sections and apertures are provided in the membrane to allow water to pass through the membrane. A gutter is disposed in the valley beneath the apertures to collect water and discharge it away from the crop growing area.

Abstract: A hook for suspending or supporting, from a rod or wire, a retractable roof covering used on greenhouses, comprises a pin for engaging the covering, a separator for preventing the covering material from contacting the rod or wire, and a locking mechanism for locking the pin and preventing the covering and rod or wire from being disengaged. The components of the hook are parts of a unitary body generally having a ring or loop shape.

Abstract: A roof structure to protect a crop growing area includes a retractable roof membrane or curtain that defines pitched sections of the roof. The membrane extends across the valley between pitched sections and apertures are provided in the membrane to allow water to pass through the membrane. A gutter is disposed in the valley beneath the apertures to collect water and discharge it away from the crop growing area.

Abstract: A roof structure to protect a crop growing area includes a retractable roof membrane or curtain that defines pitched sections of the roof. The membrane extends across the valley between pitched sections and apertures are provided in the membrane to allow water to pass through the membrane. A gutter is disposed in the valley beneath the apertures to collect water and discharge it away from the crop growing area.

Abstract: A curtain system includes two portions of a curtain each mounted on a common guide. Each portion is dimensioned to cover a predetermined area so that the portions may be deployed alternatively. One of the portions is selectively engageable with a drive cable to allow deployment of one or the other portion by the cable.