Abstract: A slot ventilator having a canopy with a downwardly facing air inlet and a rear wall having an air outlet which, in use, leads to the slot with which the ventilator is associated includes at least one longitudinally extending baffle which increases the flow path between the inlet face and the outlet, at least one surface of the baffle being formed with corrugations which reduce noise generated by air flowing through the ventilator. The ventilator comprises a profile member affording upper and front walls of the canopy and at least one insert slidable longitudinally into the profile member and affording the baffle or baffles. Preferably, the ventilator includes at least two of the said inserts, one being longer than the other.

Abstract: A sliding sash window ventilator assembly for insertion between the window sashes and the window frame comprises an elongate ventilator housing having an air passage through and between its inner and outer lateral faces and an elongate facing member mounted by a parallel motion linkage onto said ventilator housing, such that lengthwise movement of said facing member produces movement of said facing member towards or away from said housing between a fully closed position obstructing said air passage and a fully open position.

Abstract: A sliding sash window ventilator assembly for insertion between one sash and the window frame. A ventilation channel is closable by a facing member mounted by a parallel motion linkage for adjustment of its position. The facing member is disposed and mounted such that it fails to extend beyond the overall dimensions of the ventilator assembly even when fully open, to thus avoid obstructing motion of the sashes. Preferably, the facing member is mounted on external flange members of the assembly for ease of construction.

Abstract: A vehicle wheel attachment offers an increased tread to support the vehicle on soft ground, snow or sand. A rigid version has a body (5) of revolution which is clamped co-axially against the wheel (1) using a screw device (7,19) anchored to the studs which mount the wheel. The body is generally frusto-conical and may be made buoyant or be ballasted. There are also inflatable (29) and telescopic versions which can be collapsed and stowed against the wheel.