The present invention provides a fan (100) that includes a hub (102) and a plurality of blades (104). The hub (102) has a blade attachment surface (106) that extends around the circumference of the hub (102). The blades (104) extend from the blade attachment surface (106). Each of the blades (104) has...http://www.google.de/patents/US6086330?utm_source=gb-gplus-sharePatent US6086330 - Low-noise, high-performance fan
