| 摘要 |
1490778 Centrifugal blowers TORIN CORP 5 May 1975 [24 May 1974] 18767/75 Heading F1C [Also in Division B3] A blower wheel comprises a sheet metal blade strip 12, Fig. 2, comprising arcuate blades 18, Figs. 2 and 3, extending between narrow side margins 16. The initially flat strip 12 is wrapped around a sheet metal support disc 30, Fig. 8, so that each blade 18 enters a corresponding opening 32 in the periphery of the disc 30 and rests against a side edge 38 of the opening with notches 28 in the blade engaging end edges 42, 44 of the opening to locate the blade against radial or axial displacement relative to the support disc. The abutting ends of the side margins 16 are then connected together, preferably by welding. Portions 52 of the disc 30, which had previously been bent up from the plane of the disc through an angle of between 45 degrees and 90 degrees to facilitate insertion of the blades 18 into the openings 32 are then re-bent into the plane by means of a press tool to provide a further side edge 40 of the opening 32 as shown in Fig. 10. |
