Abstract: A cross flow fan (10) imparts both radial and axial flow components to airflow passing through the fan, resulting in a conical exit airflow. The fan includes a hub (12) and circumferentially spaced, radially extending fan blades (14, 16, 18, 20, 22, and 24). Backing plate portion (34, 36, 38, 40, 42, and 44) is associated with each of the blades 14-24. The backing plate portions lie on a conical plane which rakes backwardly from the hub in a direction downstream from the fan. The fan blades are disposed in a plane oblique to their corresponding backing plate portions, so that they intersect the latter along a joining edge (50). Each of the fan blades includes portions having greater (56) and lesser (58) radii of curvature. The portions (58) of lesser radii of curvature cooperate with the corresponding backing plate portions (36) to provide a radial component to the flow through the fan whereas the leading edge portions (56) provide the axial flow component.

Abstract: A vehicle emissions control system includes an air pump (12), a catalytic converter (22) communicated to the air pump, and a bleed control valve (28) which controls the quantity of air communicated from the air pump to the catalytic converter. The bleed valve includes a support arm (50) which suspends a valve element (40) adjacent a tapered valve surface (36). The support arm relaxes in response to repeated flexing due to the pulsating output of the air pump. Accordingly, when the vehicle is new, the valve element is held away from the valve seat to permit substantially uninhibited communication through the bleed valve so that almost all of the air which would otherwise be communicated to the catalytic converter is bled off.