Sheet metal fan assembly

Claim 2

A sheet metal fan assembly comprising, in combination: a sheet metal hub comprising a central portion and a plurality of arms integral with and projecting radially from said central portion, each arm presenting a forwardly facing mounting pad surface spaced outwardly from said central portion and said central portion having a marginal flange having a forwardly facing surface merging with said mounting pad surface, each mounting pad surface being twisted out of the plane of said marginal flange; a sheet metal fan blade for each arm, each fan blade having an inner end portion overlapping a corresponding mounting pad surface and being securely fixed thereagainst, whereby each fan blade likewise is twisted out of the plane of said marginal flange, and each fan blade including an outer end projecting radially outwardly beyond its corresponding mounting pad surface and terminating in a forwardly bent tip portion; said central portion of the hub including an inner portion offset rearwardly from but parallel to said marginal flange and presenting a mounting surface on its rear face for connection to an engine-driven drive member and a side wall joining said inner portion with said marginal flange, and each arm having a radially extending trough therein interrupting said side wall and merging smoothly with said inner portion of the hub and extending radially outwardly into the area of said mounting pad surface, said trough defining a reinforcing rib bulging outwardly from the rearward side of its arm; and each blade having a radially extending trough therein extending outwardly from the inner end of the blade in registry with the reinforcing rib of its corresponding arm, said trough in the blade defining a reinforcing rib bulging outwardly from the forward side of the blade.

Claim 3

A sheet metal fan assembly as defined in claim 1 wherein said mounting pad surface is flat and of generally triangular configuration, each blade also having a mating generally triangular flat area on its inner end portion.

Claim 4

A sheet metal fan assembly as defined in claim 2 wherein each fan blade is of generally rectangular plan view, the amount by which each blade is twisted out of the plane of said marginal flange of the hub and the amount of forward bending of the tip of each blade being such that the width of the blade as projected onto a plane normal to the plane of said marginal flange of the hub is widest at said fowardly bent tip of each blade.

Claim 5

A sheet metal fan assembly as defined in claim 1 wherein each blade is provided with a generally U-shaped trough forming generally Y-shape with its radial trough and defining reinforcing rib arms bulging forwardly from the fan blade and branching from the radial rib to merge into the fan blade body radially beyond said mounting pad portion of its corresponding arm.

Claim 6

A sheet metal fan assembly comprising, in combination: a sheet metal hub comprising a central portion and a plurality of arms integral with and projecting radially from said central portion, each arm presenting a forwardly facing mounting pad surface spaced radially outwardly from said central portion and said central portion having a marginal flange having a forwardly facing surface merging with said mounting pad surface, each mounting pad surface being twisted out of the plane of said marginal flange; a sheet metal fan blade for each arm, each fan blade having an inner end portion overlapping a corresponding mounting pad surface and being securely fixed thereagainst, whereby each fan blade likewise is twisted out of the plane of said marginal flange, and each fan blade including an outer end projecting radially outwardly beyond its corresponding mounting pad surface and terminating in a forwardly bent tip portion; said central portion of the hub including an inner portion offset rearwardly from but parallel to said marginal flange and presenting a mounting surface on its rear face for connection to an engine-driven drive member and a side wall joining said inner portion with said marginal flange, and each arm having a radially extending through therein interrupting said side wall and merging smoothly with said inner portion of the hub and extending radially outwardly into the area of said mounting pad surface, said trough defining a reinforcing rib bulging outwardly from the rearward side of its arm; each blade having a radially extending trough therein extending outwardly from the inner end of the blade in registry with the reinforcing rib of its corresponding arm, said trough in the blade defining a reinforcing rib bulging outwardly from the forward side of the blade, the tip of each blade being curved away from the remainder of the blade, thereby to induce radially outward flow of air, the tips defining the widest part of the projected width of the fan assembly.

Claim 7

A sheet metal fan assembly comprising, in combination: a sheet metal hub comprising a central portion and a plurality of arms integral with and projecting radially from said central portion, each arm presenting a forwardly facing mounting pad surface spaced radially outwardly from said central portion and said central portion having a marginal flange having a forwardly facing surface merging with said mounting pad surface, each mounting pad surface being twisted out of the plane of said marginal flange; a sheet metal fan blade for each arm, each fan blade having an inner end portion overlapping a corresponding mounting pad surface and being securely fixed thereagainst, whereby each fan blade likewise is twisted out of the plane of said marginal flange, and each fan blade including an outer end projecting radially outwardly beyond its corresponding mounting pad surface and terminating in a forwardly bent tip portion; said central portion of the hub including an inner portion offset rearwardly from but parallel to said marginal flange and presenting a mounting surface on its rear face for connection to an engine-driven drive member and a side wall joining said inner portion with said marginal flange, and each arm having a radially extending through therein interrupting said side wall and merging smoothly with said inner portion of the hub and extending radially outwardly into the area of said mounting pad surface, said trough defining a reinforcing rib bulging outwardly from the rearward side of its arm; each blade having a radially extending trough therein extending outwardly from the inner end of the blade in registry with the reinforcing rib of its corresponding arm, said trough in the blade defining a reinforcing rib bulging outwardly from the forward side of the blade, the tip of each blade being curved away from the remainder of the blade, thereby to induce radially outward flow of air, the tips defining the widest part of the projected width of the fan assembly.

Claim 8

A sheet metal fan assembly as defined in claim 5 wherein said mounting pad surface is flat and of generally triangular configuration, each blade also having a mating generally triangular flat area on its inner end portion.

Claim 9

A sheet metal fan assembly as defined in claim 6 wherein each fan blade is of generally rectangular plan view, the amount by which each blade is twisted out of the plane of said marginal flange of the hub and the amount of forward bending of the tip of each blade being such that the width of the blade as projected onto a plane normal to the plane of said marginal flange of the hub is widest at said forwardly bent tip of each blade.

Claim 10

A sheet metal fan assembly as defined in claim 5 wherein each blade is provided with a generally U-shaped trough forming generally Y-shape with its radial trough and defining reinforcing rib arms bulging forwardly from the fan blade and branching from the radial rib to merge into the fan blade body radially beyond said mounting pad portion of its corresponding arm.