摘要 |
1,068,118. Making turbine and like blades. VENTILATOR A.G. May 27, 1965 [May 29, 1964], No. 22673/65. Heading B3A. [Also in Division F1] The vanes of an axial-flow blower (see Division F1) are each formed in one piece from sheet metal, e.g. aluminium, by cutting a sheet metal strip of trapezoidal form, pressing or otherwise forming it into a twisted vane, bending the wide end to a position approximately at right angles to the vane to form a base portion, and pressing or stamping the base into an arched or part-spherical configuration. |