Abstract: A self-locking window operator has a reversible rotary drive shaft connectable in sequence to separate linkages respectively controlling movement of a casement relative to a surrounding frame and actuation of a fastening mechanism for releasably securing the casement when closed. The drive shaft is coupled by a worm gear to a drive input member rotatable about a drive axis and each linkage has a drive output member rotatable about separate axes offset from the drive axis. The input member has a drive pin co-operable with a respective pin receiving recess of each output member for sequentially operating the linkages.

Abstract: A two-part plastics ventilator comprises a housing defining a ventilation opening, a flap pivotal to open and close the opening, and spring legs integral with the housing to bias the flap to the open and closed positions.

Abstract: A fastener 1 has two elongate bars 2,3 slidably mounted in a guide track 4 for simultaneous displacement longitudinally thereof in opposite directions under the action of a rotatable handle 6. Each bar 2,3 has an associated rack and pinion assembly 7,8 for transposing rotation of the handle 6 into linear displacement of the bar.