| 摘要 |
A propeller fan comprising a pair of similar sheet metal spider-blade members each having a flat central hub section and two right angularly arranged pairs of narrow radially outwardly projecting spider arms. Each spider arm is twisted at an intermediate portion so that radially outer end portions of the arms of each pair are inclined in opposite directions relative to the hub section. A pair of air moving blades are formed integrally at inner end portions respectively with the outer end portions of the spider arms of one of the pairs of arms. A pair of laterally projecting blade support members are integrally formed respectively with the outer end portions of the other pair of spider arms. Each blade support member is approximately twice as wide as each spider arm and each blade is approximately four times as wide as each spider arm. The width and length of each blade are approximately equal. The two spider-blade members are right angularly arranged with the hub sections and spider arms in contiguous face-to-face relationship and the lateral support members of one member in face-to-face engagement with and supporting inner end portions of the blades of the other member. Spot welding at spaced areas throughout the hub section, the spider arms, and the support members and blades secures the two spider-blade members in operative relationship to form the propeller fan.
|
