A rotatable centrifugal fan blade assembly and air flow circulation apparatus.

摘要

A rotatable centrifugal fan blade assembly comprises substantially parallel circular disk members (9,56) at least one of which has a centrally disposed aperture (19). Blade members (20-31) are each disposed on a plane substantially normal to the planes of the disk members and extend therebetween. At least one of the disk members has cut-outs (44-55) each of which is located between the connection between two adjacent blade members with one of the disks and each of which is defined by a larger area disposed towards the trailing edge of one of the two blade members and by a smaller area disposed towards the face side of the other of the two blade members.