Abstract: A shaft and pulley assembly for a blower having a scroll housing containing an impeller utilizes a square section shaft having a pulley retained thereon, an impeller having a hub with inner surfaces which lie in face-to-face contiguity with the shaft, a pair of adaptors having inner surfaces which also lie in face-to-face contiguity with the shaft and having curved external surfaces which support the adaptors from bearings which are themselves carried in bearing housings which are fixed with respect to the scroll housing, at least one of the adaptors having latches thereon which retain its said bearing against displacement.

Abstract: A boss of a pulley is provided with interference lobes which are directed radially inwardly and which, upon assembly, bear against the surfaces of a non-circular shaft and cause consequential deformation of the boss. This ensures a continued pressure between the boss and the shaft which can result in firm retention of the pulley to the shaft, notwithstanding the inherent dimensional instability of polymeric material.

Abstract: An evaporative cooler pad assembly comprising a pad of absorbent material, e.g. woodwool is retained between a pair of side grids each of which has projections which interengage the other, and at least some of the projections extend through the pad and support it.

Abstract: A spreader plate having a water receiving area which receives water from a pump, a plurality of ribs radiating outwardly from the central water receiving area, the lengths and spacing of the ribs being such as to divide the water up into a plurality of streams of approximately equal intensity, and a cover over the water receiving area comprising a deflector which deflects water flow over the water receiving area in a constant thickness film and into the channels between the ribs.

Abstract: A baffle is upstanding from the base of an evaporative cooler tank, and a spreader has a depending flange, the pad frames having their lower ends located and supported by the upper edge of the baffle and their upper ends engaged and located by the depending spreader flange.