Abstract: The purpose of this Air Vent is to safeguard the security of the public potable water system, especially in such enclosed structures as reservoir and clearwell and other vital air vented installations against sabotages, vandalism and other accidental contamination by animals or birds.

Abstract: A modular louver assembly comprises a peripheral frame having a sill, a header and jambs defining a rectangular primary opening, a plurality of intermediate frame members joined to the peripheral frame and dividing the primary opening into a plurality of rectangular modular unit openings, and either louver modules or blank-off panels received in the unit openings. A sight screen mounted on the framework overlies substantially the entire primary opening.

Abstract: A louvre type roof structure includes a plurality of parallel slats mounted on carrier elements which in turn are mounted on carrier beams such as to permit pivotal displacement of the carrier elements and the slats between a closed position in which the slats are disposed in a roughly coplanar orientation, and an open position in which the slats are disposed in spaced apart generally parallel planes. The carrier elements are secured to the slats by engaging the slats without penetrating the slats, so that each slat is located in a fixed planar orientation relative to the respective carrier. Mounting of the carrier elements to the carrier beams is by means of a pair of mounting levers for each carrier element. One of the pair of mounting levers is a fixed lever securable to a carrier beam in a selected position, and the other lever is a free lever displaceable relative to a carrier beam.

Abstract: A ventilator for buildings comprising a cylindrical main body which is open at both ends and provided with a plurality of seating members installed at attachment holes opened in the cylindrical circumferential wall of the main body. The seating members having surfaces conforming to the curvature of the cylindrical main body and also having perpendicular ends for holding the slats securely by screws.

Abstract: A louvre type roof structure including a plurality of parallel slats mounted on carrier beams extending transversely to the slats, in which the slats are mounted on carrier elements which are in turn mounted on the carrier beams to permit pivotal displacement of the carrier elements and of the slats between a closed position in which they are disposed in a roughly coplanar position, and an open position in which they are disposed in spaced apart parallel planes. The carrier elements are secured to the slats by means of lugs engaging the slats without penetrating the slats. The carrier elements are mounted on the carrier beams by mounting levers, a pair of mounting levers being provided in respect of each carrier element, one of a pair of levers being a fixed lever and being secured to the carrier beam in a fixed position, and the other one being a free lever and being displaceable relative to the carrier beam.