초록 ▼

The axial fan produced by the novel method may have a cylindrical shroud, an impeller mounted coaxially within the shroud, and a bell-shaped deflector extending across the exhaust to redirect the airflow toward radially outward directions. A malleable blank may be cut and shaped to form the impeller

The axial fan produced by the novel method may have a cylindrical shroud, an impeller mounted coaxially within the shroud, and a bell-shaped deflector extending across the exhaust to redirect the airflow toward radially outward directions. A malleable blank may be cut and shaped to form the impeller having at least three blades, the peripheries of which define a cylinder coaxial with the shroud. The impeller should have a depth-to-radius ratio exceeding 0.5.

대표청구항 ▼

A method of making an axial fan impeller comprising the steps of (a) forming in a flat malleable blank n generally radial cuts extending from first points equally spaced along a central circle, n being an integer of at least 3, n symmetrical first spiral cuts, each extending outwardly from a second

A method of making an axial fan impeller comprising the steps of (a) forming in a flat malleable blank n generally radial cuts extending from first points equally spaced along a central circle, n being an integer of at least 3, n symmetrical first spiral cuts, each extending outwardly from a second point on said circle between adjacent first points to a third point on an adjacent generally radial cut, and n symmetrical second spiral cuts extending from fourth points at the outward extremities of the generally radial cuts, each second spiral cut extending generally parallel to the radially adjacent first spiral cut, an extension of each second spiral cut terminating at the next second spiral cut, (b) shaping each portion of the blank between radially adjacent first and second spiral cuts to provide n air-driving blades, the peripheries of which along the n second spiral cuts together generally define a cylinder coaxial with said central circle, and (c) forming each portion of the blank between said central circle and one of said first spiral cuts not to extend radially beyond the circle.