Ceiling fan and impeller blade

1. A ceiling fan comprising:

a body having an outer periphery and a bottom, the body defining an annular air flow passage with an annular inlet in the bottom, and an annular outlet provided on the outer periphery of the body;

a motor having a rotor, defining a rotational axis, with at least a portion of the rotor located within the body;

an impeller mounted to the rotor to move air through the air flow passage;

an annular grill located radially exteriorly of the impeller and circumscribing the annular outlet such that air passing through the annular air flow passage and exiting the annular outlet passes through the grill; and

a set of blades provided on the impeller, the set of blades located within the annular air flow passage and circumferentially spaced about the annular air flow passage, with at least one blade of the set of blades extending from a root to a tip in a span-wise direction, and extending from a first edge to a second edge defining a chord-wise direction, wherein at least some tips of the blades include an extension extending outward at the tip.

2. The ceiling fan of claim 1 wherein the second edge includes a straight linear portion extending radially outwardly from the root.

3. The ceiling fan of claim 2 wherein the second edge further includes a first curved portion extending from the straight linear portion.

4. The ceiling fan of claim 3 wherein the first curved portion is convex.

5. The ceiling fan of claim 3 wherein the second edge further includes a second curved portion extending from the first curved portion.

6. The ceiling fan of claim 5 wherein the second curved portion is concave.

7. The ceiling fan of claim 6 wherein an inflection point is defined on the second edge at a junction between the first curved portion and the second curved portion.

8. The ceiling fan of claim 6 wherein the second curved portion terminates at the tip.

9. The ceiling fan of claim 1 wherein the extension is curvilinear.

10. The ceiling fan of claim 1 further comprising a second extension defining a valley between the extension and the second extension.

11. The ceiling fan of claim 1 wherein each blade of the set of blades includes a hyperbolic paraboloid shape.

12. The ceiling fan of claim 1 wherein the annular grill further includes a set of grill extensions arranged complementary to the extensions extending from the tip of each blade of the set of blades.

13. The ceiling fan of claim 1 wherein the annular grill includes a set of ribs connected by a vertical wall, wherein the vertical wall can be angled complementary to a flow of air exhausting from the annular air flow passage.

14. A blade for a ceiling fan impeller, the blade comprising:

a body extending between a root and a tip, defining a span-wise direction, and extending between a first edge and a second edge, defining a chord-wise direction; and

a set of extensions extending from the body at the tip;

wherein the second edge includes a straight linear portion extending radially outwardly from the root and the second edge extends between the root and the tip, and includes a first curved portion and a second curved portion.

15. The blade of claim 14 wherein the first curved portion is convex and the second curved portion is concave, and the first curved portion meets the second curved portion at an inflection point.

16. An impeller for a ceiling fan comprising:

a hub having an inner wall defining an interior motor chamber, and a top wall extending radially from an upper edge of the inner wall;

a set of blades extending radially from the hub;

wherein each blade of the set of blades includes a root and a tip and opposing first and second edges, with the first edge spaced from the second edge, and which extend between the root and the tip, wherein the root is attached to the inner wall, the first edge is attached to the top wall, and the tip includes a set of extensions extending radially outwardly from each blade of the set of blades;

wherein each blade of the set of blades includes a bottom edge extending between the root and the tip, with the bottom edge including a straight linear portion extending from the root, a convex portion extending from the straight linear portion, and a concave portion extending between the convex portion and the tip.

17. The impeller of claim 16 wherein each blade of the set of blades includes a hyperbolic paraboloid shape.

18. A ceiling fan comprising:

a body defining an air flow passage with an inlet provided on a lower surface of the body and an outlet provided on an outer periphery of the body;

a motor having a rotor, with at least a portion of the rotor located within the body;

an impeller mounted to the rotor to move air through the air flow passage;

a grill located radially exteriorly of the impeller and facing circumscribing the outlet such that air passing through the air flow passage and exiting the outlet passes through the grill; and

a set of blades provided on the impeller, the set of blades located within the flow passage and circumferentially spaced about the flow passage, with at least one blade of the set of blades extending from a root to a tip in a span-wise direction, and extending from a first edge to a second edge defining a chord-wise direction, wherein at least some tips of the blades include an extension extending outward at the tip, the second edge includes a straight linear portion extending radially outwardly from the root, and the second edge further includes a first curved portion extending from the straight linear portion.