Fan blade mounting structures and arrangements

Abstract

Example axial fans (overhead fans) include a set of radially extending spokes that connect a set of fan blades to a motor-driven hub. Each spoke has at least one notch, so the spokes can be assembled in interlocking relationship with each other, such that the spokes extend at different rotational angles from the rotational axis of the hub but lie in substantially the same horizontal plane. Such an arrangement enables the spokes to support the cantilevered weight and other vertical loads exerted by the fan blades while providing a compact assembly. In some examples, a retainer extends through aligned bores of several components of the fan along the axis of rotation.

1 . An overhead fan comprising:
 a housing;   a hub being rotatable relative to the housing about a rotational axis that is perpendicular to a radial direction;   a first fan blade;   a first spoke connecting the first fan blade to the hub;   a second fan blade; and   a second spoke connecting the second fan blade to the hub, the second spoke overlapping the first spoke to define an overlapping interface between the first spoke and the second spoke, the overlapping interface lying substantially perpendicular to the rotational axis, both the first spoke and the second spoke extending lengthwise in the radial direction across the rotational axis.   
     
     
         2 . The overhead fan of  claim 1 , wherein the first spoke defines a first notch at the rotational axis, the second spoke defines a second notch at the rotational axis, and the overlapping interface is between the first notch and the second notch. 
     
     
         3 . The overhead fan of  claim 1 , further comprising:
 a first inboard screw fastening the first spoke to the hub;   a first outboard screw fastening the first spoke to the hub, the first fan blade being closer to the first inboard screw than to the first outboard screw, the first inboard screw and the first outboard screw being at opposite sides of the rotational axis;   a second inboard screw fastening the second spoke to the hub; and   a second outboard screw fastening the second spoke to the hub, the second fan blade being closer to the second inboard screw than to the second outboard screw, the second inboard screw and the second outboard screw being at opposite sides of the rotational axis.   
     
     
         4 . The overhead fan of  claim 1 , wherein the first spoke defines a first hole, the second spoke defines a second hole, and the rotational axis extends through both the first hole and the second hole. 
     
     
         5 . The overhead fan of  claim 4 , further comprising:
 a hollow shaft extending from the housing and being substantially fixed relative thereto;   a bearing coupling the hub to the hollow shaft; and   a retainer that is vertically elongate, the retainer extending through the hollow shaft, through the first hole in the first spoke, and through the second hole in the second spoke; the retainer being in substantially fixed rotational relationship with the hollow shaft, the retainer including a catch member below both the first hole and the second hole, the catch member have an outermost periphery, at least one of the first hole and the second hole having an innermost periphery, the rotational axis being closer to the innermost periphery than to the outermost periphery.   
     
     
         6 . The overhead fan of  claim 1 , further comprising:
 a third fan blade; and   a third spoke connecting the third fan blade to the hub, the third spoke having a section sandwiched between the first spoke and the second spoke at the overlapping interface.   
     
     
         7 . The overhead fan of  claim 1 , further comprising a third fan blade connected to the first spoke. 
     
     
         8 . An overhead fan comprising:
 a housing;   a hollow shaft extending from the housing;   a hub;   a bearing coupling the hub to the hollow shaft such that the hub is rotatable relative to the housing about a rotational axis;   a first fan blade;   a first spoke connecting the first fan blade to the hub, the first spoke defining a first hole;   a second fan blade; and   a second spoke connecting the second fan blade to the hub, the second spoke defining a second hole; and   a retainer that is vertically elongate, the retainer extending through the hollow shaft, through the first hole in the first spoke, and through the second hole in the second spoke; the retainer being in substantially fixed rotational relationship with the housing, the retainer including a catch member below both the first hole and the second hole, the catch member have an outermost periphery, at least one of the first hole and the second hole having an innermost periphery, the rotational axis being closer to the innermost periphery than to the outermost periphery.   
     
     
         9 . The overhead fan of  claim 8 , wherein the rotational axis is perpendicular to a radial direction, the second spoke overlaps the first spoke to define an overlapping interface between the first spoke and the second spoke, the overlapping interface lies substantially perpendicular to the rotational axis, and both the first spoke and the second spoke extend in the radial direction across the rotational axis. 
     
     
         10 . The overhead fan of  claim 9 , wherein the first spoke defines a first notch at the rotational axis, the second spoke defines a second notch at the rotational axis, and the overlapping interface is between the first notch and the second notch. 
     
     
         11 . The overhead fan of  claim 9 , further comprising:
 a third fan blade; and   a third spoke connecting the third fan blade to the hub, the third spoke having a section sandwiched between the first spoke and the second spoke at the overlapping interface.   
     
     
         12 . The overhead fan of  claim 8 , further comprising a third fan blade connected to the first spoke. 
     
     
         13 . The overhead fan of  claim 8 , further comprising:
 a first inboard screw fastening the first spoke to the hub;   a first outboard screw fastening the first spoke to the hub, the first fan blade being closer to the first inboard screw than to the first outboard screw, the first inboard screw and the first outboard screw being at opposite sides of the rotational axis;   a second inboard screw fastening the second spoke to the hub; and   a second outboard screw fastening the second spoke to the hub, the second fan blade being closer to the second inboard screw than to the second outboard screw, the second inboard screw and the second outboard screw being at opposite sides of the rotational axis.   
     
     
         14 . The overhead fan of  claim 8 , wherein the rotational axis extends through the hollow shaft, through the first hole of the first spoke and through the second hole of the second spoke. 
     
     
         15 . An overhead fan comprising:
 a housing;   a hub being rotatable relative to the housing about a rotational axis;   a first fan blade being rotatable to define a path of rotation;   a first spoke connecting the first fan blade to the hub, the first spoke having a first shape;   a second fan blade being rotatable along the path of rotation; and   a second spoke connecting the second fan blade to the hub, the second spoke having a second shape that is distinguishable from the first shape.   
     
     
         16 . The overhead fan of  claim 15 , wherein the first spoke and the second spoke are substantially equal in length. 
     
     
         17 . The overhead fan of  claim 15 , wherein the second spoke overlaps the first spoke to define an overlapping interface between the first spoke and the second spoke, the overlapping interface lying substantially perpendicular to the rotational axis, both the first spoke and the second spoke extending lengthwise in a radial direction across the rotational axis, wherein the radial direction is perpendicular to the rotational axis. 
     
     
         18 . The overhead fan of  claim 15 , wherein the first spoke defines a first notch, the second spoke defines a second notch, and the first notch and the second notch overlap each other. 
     
     
         19 . The overhead fan of  claim 15 , further comprising:
 a first inboard screw fastening the first spoke to the hub;   a first outboard screw fastening the first spoke to the hub, the first fan blade being closer to the first inboard screw than to the first outboard screw, the first inboard screw and the first outboard screw being at opposite sides of the rotational axis;   a second inboard screw fastening the second spoke to the hub; and   a second outboard screw fastening the second spoke to the hub, the second fan blade being closer to the second inboard screw than to the second outboard screw, the second inboard screw and the second outboard screw being at opposite sides of the rotational axis.   
     
     
         20 . The overhead fan of  claim 15 , wherein the first spoke defines a first hole, the second spoke defines a second hole, the rotational axis extends through both the first hole and the second hole, and the overhead fan further comprising:
 a hollow shaft extending from the housing;   a bearing coupling the hub to the hollow shaft; and   a retainer that is vertically elongate, the retainer extending through the hollow shaft, through the first hole in the first spoke, and through the second hole in the second spoke; the retainer including a catch member below both the first hole and the second hole, the catch member have an outermost periphery, at least one of the first hole and the second hole having an innermost periphery, and the rotational axis being closer to the innermost periphery than to the outermost periphery.