CN111852941B - Blade for ceiling fan - Google Patents

Abstract

The present disclosure relates to blades for ceiling fans. A ceiling fan or similar means of moving air may include a motor for rotating one or more blades to drive a volume of air around a space. The blade may include a body having an outer surface with a flat top surface and a flat bottom surface and side edges. The curved transition may extend between the side edge and one of the flat top surface and the flat bottom surface. The curved transition may comprise an elliptical curve.

Description

Blade for ceiling fan

Technical Field

The present disclosure relates to a blade for a ceiling fan.

Background

Ceiling fans are machines that are typically suspended from a structure for moving a volume of air around an area. The ceiling fan includes a motor having a rotor and a stator and suspended from and electrically coupled to the structure. A set of blades is mounted to the rotor such that the blades are rotatably driven by the rotor and the blades can be disposed in an angular orientation to move a volume of air around the region. As energy costs become more and more important, there is a need to increase the efficiency of ceiling fans when they are operated.

Disclosure of Invention

In one aspect, the present disclosure is directed to a blade for a ceiling fan having a fan motor for rotating the blade. The blade includes a body having an outer surface extending in a spanwise (span-wise) direction between a root and a tip and in a chordwise (chord-wise) direction between a first side edge and a second side edge. The outer surface has a top surface and a bottom surface, and the curved transition on the top surface has a curvature extending to the first side edge or the second side edge, the curved transition having a chordwise length greater than any transition on the bottom surface.

In another aspect, the present disclosure is directed to a blade for a ceiling fan, the blade having a chordwise direction. The blade includes a planar upper surface and a planar lower surface opposite the planar upper surface. Side edges having a width space the planar upper surface from the planar lower surface. The first curved transition transitions between the first side edge and the flat upper surface, and the first curved transition has a chordwise width greater than any transition between the flat lower surface and the side edge.

Drawings

In the drawings:

FIG. 1 is a schematic view of a structure with a ceiling fan suspended from the structure and including a set of blades.

FIG. 2 is a top view of one of the set of blades of FIG. 1 having a curved surface that transitions to the blade edge.

FIG. 3 is a cross-sectional view of the blade of FIG. 2, showing curved transitions to the blade edge on the top and bottom surfaces.

FIG. 4 is an enlarged cross-sectional view of one edge of the blade of FIG. 3, showing an elliptically curved surface of the blade.

FIG. 5A is a cross-sectional view of another exemplary blade, illustrating a chamfered surface taken through section VA-VA of FIG. 5B.

FIG. 5B is a top-down view of the blade of FIG. 5A including a chamfered surface extending along the leading edge, trailing edge, and tip of the blade.

Detailed Description

The present disclosure relates to a ceiling fan and ceiling fan blades that may be used, for example, in residential or commercial applications. These applications may be indoor, outdoor, or both. Although the present description is primarily directed to residential ceiling fans, it may also be applied to any environment that utilizes ceiling fans or for cooling an area using air movement.

As used herein, the term "set" or "group" of elements may be any number of elements, including just one. All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, transverse, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, rearward, etc.) are used merely for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly with respect to the position, orientation, or use of the aspects of the present disclosure as described herein. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a series of members and relative movement between members unless otherwise indicated. Likewise, a connective reference does not necessarily refer to two elements directly connected and fixed relative to each other. The exemplary drawings are for illustrative purposes only and the dimensions, positions, order and relative sizes reflected in the accompanying drawings may vary.

Referring now to FIG. 1, a ceiling fan 10 is suspended from a structure 12. In a non-limiting example, the ceiling fan 10 may include one or more ceiling fan components including a suspension 14, a cover 16, a lower pole 18, a motor adapter 20, a motor housing 22 at least partially enclosing a motor 24 having a rotor 26 and a stator 28, a light kit 30, and a set of blade irons 32. In other non-limiting examples, the ceiling fan 10 may include one or more controllers, wireless receivers, ball mounts, suspension balls, light fixture glass, light cages, spindles, tip decorations, switch housings, blade prongs, blade tips or blade covers, or other ceiling fan components. A set of blades 34 may extend radially from the ceiling fan 10, and the blades may be rotatable to drive a volume of fluid (such as air). The blades 34 may be operatively coupled to the motor 24 at the rotor 26, such as via a blade iron 32. The blades 34 may include a set of blades 34 having any number of blades, including having only one blade.

The structure 12 may be a ceiling, for example, from which the ceiling fan 10 is suspended. It should be appreciated that the structure 12 is shown schematically by way of example only, and may include any suitable building, structure, home, business, or other environment suitable or requiring a ceiling fan to move air. The structure 12 may also include a power source 36, and the power source may be electrically coupled to the ceiling fan 10 to provide power to the ceiling fan 10 and the motor 24 thereon. It is also contemplated that the power source may come somewhere outside of the structure 12, such as a battery or generator in a non-limiting example.

The controller 38 may be electrically coupled to the power supply 36 to control the operation of the ceiling fan 10 via the power supply 36. Alternatively, the controller 38 may be coupled to the ceiling fan 10 wirelessly or communicatively and configured to remotely control operation of the ceiling fan 10 without a dedicated connection. Non-limiting examples of controls for the ceiling fan 10 may include fan speed, fan direction, or lamp operation. Further, a separate wireless controller 40 may be communicatively coupled to a controller or wireless receiver located in the ceiling fan 10 to control operation of the ceiling fan 10, either alone or in addition to the wired controller 38. It is also contemplated that in an alternative example, the ceiling fan is operated solely by the wireless controller 40 and is not operatively coupled to the wired controller 38.

Referring to FIG. 2, one blade 34 is shown separated from the rest of the ceiling fan 10 of FIG. 1 for purposes of illustration. Three fastener holes 50 are provided in the blade 34 for securing the blade to the motor 24 for rotating the blade 34 about the ceiling fan 10, preferably via the blade irons 32. Any number of fastener holes or indeed any method or mechanism of blade attachment is within the scope of the present disclosure. The vane 34 includes an outer surface 52 that includes a top surface 54. The top surface 54 terminates at a side edge 56. The top surface 54 may include a flat portion 58 and a top curved transition portion 60 that transitions from the flat portion 58 to the side edge 56. Alternatively, the top surface need not be flat, but may include alternative geometries that extend to the curved transition 60. In one example, the curved transition 60 may be about 1 inch from the top surface 58 to the side edge 56, while any width is contemplated. In another example, the curved transition 60 may extend between 5% -40% of the chordwise width of the blade between the opposite side edges 56, however, it is contemplated that the distance may be less than 5% or greater than 40%.

The blade 34 also includes a tip 62 and a root 64, the root 64 being adjacent the fastener hole 50 and the tip 62 being opposite the root 64. For example, the curved corner 66 transitions between the top end 62 and the side edge 56, while it should be appreciated that the curved corner 66 is optional or may include other shapes, such as sharp corners. The chordwise direction may be defined between the opposite side edges 56, while the spanwise direction may be defined between the tip 62 and the root 64. The blade 34 may widen extending in the spanwise direction from the root to the tip, and the widening is defined in the chordwise direction, however any top-down shape is contemplated for the blade, such as having an outwardly extending chordwise width defining a taper in the spanwise direction. Non-limiting examples of blade shapes may include square, rectangular, curved, angled, or circular.

Further, the blade 34 may include a first edge 68 and a second edge 70 as the side edges 56, which may be arranged as a leading edge and a trailing edge, respectively, although the particular arrangement may vary depending on the direction of rotation of the blade. Thus, a chordwise direction may be defined between the first edge 68 and the second edge 70 to define a blade chord. As can be observed, the blade chord is shown increasing from the root 64 toward the tip 62.

Further, the curved transition 60 may extend along all of the first edge 68, the second edge 70, the tip 62, and/or the root 64. As shown, the curved transition 60 extends along the first edge 68, the second edge 70, and the tip 62, and curves at the corners 66 where the side edges 68, 70 contact the tip 62.

Referring to FIG. 3 (taken through section III-III of FIG. 2), the blade 34 further includes a bottom surface 80, which may have no flats or planar portions, and a bottom curved transition 82 from the bottom surface 80 to the side edge 56. The side edges 56 include a width 84 to define a distance that the curved transition 60 at the top surface 54 is spaced from the curved transition 82 of the bottom surface 80. In one other example, the width 84 may be zero such that the curved transition 60 immediately transitions from the top surface 54 to the curved transition 82 of the bottom surface 80. The blade 34 may be symmetrical about the centerline 86, however it is contemplated that the blade 34 may be asymmetrical, bendable, or may include other shapes and should not be limited to the symmetrical shape shown.

Further, it should be appreciated that the blades 34 may be mounted with an angle of attack (angle of attack). The angle of attack may be defined based on the angular position of the blades 34 such that the bottom surface 80 and the top surface 54 are disposed at an angle relative to a horizontal plane, or relative to a surface on which the ceiling fan is suspended or hung. The angle of attack allows the blades 34 to drive a volume of air and push the air in an upward or downward direction based on the direction and angle of movement of the blades 34. Without an angle of attack, the air movement produced by the blades 34 is minimal.

Referring now to FIG. 4, an enlarged cross-sectional view of the first edge 68 of the vane 34 better illustrates the curvature of the curved transition 60, 82. The curved transitions 60, 82 may provide a transition between the top surface 54 and the bottom surface 80 to the side edge 56 that is disposed perpendicular to the top surface 54 and the bottom surface 80. One or both of the curved transitions 60, 82 may be specifically shaped to have an elliptical arc, defining at least a portion of an elliptical profile for the curved transition 60, 82. More specifically, one or more curved transitions may be expressed by equation (1) written in a standard form:

where x represents the x-axis 90 and y represents the y-axis 88 in a Cartesian coordinate system. The x-axis 90 may be defined in a chordwise direction and the y-axis 88 may be defined in a direction extending from the top surface 54 to the bottom surface 80. Further, a represents the respective length of the ellipse on the x-axis, and b represents the respective length of the ellipse on the y-axis. It should also be appreciated that the ellipse may be a circle when a=b, which does not define a major or minor axis since the diameters are equal for circles. Furthermore, all other ellipses when a is not equal to b may be non-circular, defining a major axis as the maximum diameter and a minor axis as the minimum diameter, respectively. Thus, it is contemplated that the curved transition 60, 82 may be defined as elliptical, non-circular elliptical, parabolic, or hyperbolic.

In fig. 4, the curved transition 60 from the top surface 54 to the side edge 56 may be represented, for example, by the following equation (2):

wherein a=6 and b=1. Further, the curved transition 82 from the side edge 56 to the bottom surface 80 may be a 90 degree circular ellipse, which is represented, for example, by the following equation (3):

wherein a=2 and b=2. It should be appreciated that although the curved transition 82 at the bottom surface 80 is shown as an ellipse having equal major and minor axes and forming a circle, it may alternatively be an ellipse having unequal major and minor axes. Further, the particular equation representing the curved transition 60, 82 may be any suitable elliptical arc and should not be limited to the particular arc defined by equations (2) and (3) above.

In examples where one of the curved transitions 60, 82 is parabolic, the equation representing at least a portion of the curvature of the curved transition 60, 82 may be expressed in the following standard form:

(x-h) ² ＝4p(y-k) (4)

where focus (focus) may be defined as (h, k+p) and the guideline as y=k-p. x may represent the x-axis 90 and y may represent the y-axis 88.

In another example where one of the curved transitions 60, 82 is hyperbolic, the equation representing at least a portion of the curvature of the curved transition 60, 82 may be expressed in the following standard form:

or (b)

Wherein equation (5) is based on a horizontal transversal axis (trans axis) and equation (6) is based on a vertical transversal axis, which ultimately depends on the local coordinate system defining the curved transitions 60, 82 of the blade 34. (h, k) may be used to define the center of the hyperbola, while x may represent the x-axis 90 and y may represent the y-axis 88.

The curved transition 60 at the top surface 54 may have a chordwise extent from the side edge 56 that is greater than the chordwise extent of any curved transition 82 at the bottom surface 80, as may be observed when shown by the dashed lines 88, 90 in fig. 4. This greater chordwise extent may be defined, for example, by the greater major axis of the elliptical curvature of the curved transition 60 at the top surface 54. Further, it should be appreciated that although the blade is shown with two curved transitions 60, 82, it is contemplated that the blade 34 includes only one curved transition 60, with, for example, a corner or edge instead of the second curved transition 82, such as along a dashed line at either curved transition 60, 82. In other words, the transition 82 at the bottom surface may be a sharp corner with little radius.

It should be appreciated that one or more curved transitions 60, 82 between the top and bottom surfaces 54, 80 and the side edges 56 may provide increased efficiency to the blade 34. Since both the first and second edges 68, 70 may include curved transitions 60, 82, an increase in efficiency may be perceived in either rotational direction of the blade 34. Furthermore, the elliptical geometry for one or more curved transitions 60, 82 may provide improved efficiency to the blade 34, particularly the transition 60 located on the top surface 54, as compared to a blade without a curved transition.

It should also be appreciated that other geometries for the curved transition 60 are contemplated, such as geometries having a root function or a logarithmic function. For example, the curved transition 60 may be represented by an nth order root function:

or (b)

y＝x ^1/n (8)

Where x represents a value about the x-axis, and f (x) and y represent values about the y-axis, n representing any real number. Likewise, the nth order root function may be a square root function or a cube root function, or any variation thereof. Further, the curved transition 60 may be represented by a logarithmic equation:

y＝log _b (x) (9)

where b is a logarithmic base, x represents a value about the x-axis, and y represents a value about the y-axis.

Furthermore, it should be appreciated that different combinations of curved transitions 60 may be used with a single blade. For example, a first curved transition 60 may be used for the leading edge and a different curved transition may be used for the trailing edge. In another example, a first curved transition 60 may be used for the curved transition at the top surface 54 and a second, different curved transition 82 may be used at the bottom surface 80. In yet another example, the curved transition 60 may vary along the leading edge, trailing edge, upper surface, lower surface, or otherwise vary in the spanwise direction between the root and tip. Thus, it should be appreciated that a myriad of different curved transitions may be utilized with the ceiling fan blades, which may provide further increased efficiency, as well as being utilized in either rotational direction.

Referring now to fig. 5A and 5B, a cross-sectional profile and a top view of another blade 110 are shown, respectively. The blade 110 includes a root 108 and a tip 106, and for example, the blade may have a top-down shape generally similar to that shown in the top-down view of FIG. 2, although other variations in the top-down shape are contemplated. Blade 110 may include leading and trailing edges 112, 114 and top and bottom surfaces 116, 118. Each of the leading edge 112 and the trailing edge 114 may include a radiused or rounded transition 120 between the top surface 116 and the bottom surface 118.

The blade 110 may include at least one beveled edge 122 that transitions between the top surface 116 and one of the leading edge 112 and the trailing edge 114. As shown, the beveled edge 122 is disposed at both the leading edge 112 and the trailing edge 114. In one example, the beveled edge 122 may extend continuously around the blade 110 along the leading edge 112, tip, trailing edge 114, although it is contemplated that any one or more portions of the root, tip, leading edge 112, and trailing edge 114 may include the beveled edge 122. The beveled edge 122 may contact the leading edge 112 or the trailing edge 114 at a rounded transition 120. Similarly, a rounded or radiused transition 124 may be provided at the junction between the top surface 116 and the beveled edge 122.

In one example, the beveled edge 122 may be between 5% and 40% of the chord-wise width of the blade, extending between and measured from the leading edge 112 and the trailing edge 114. The beveled edge 122 may be disposed at an angle 130 of less than 180 degrees but greater than 90 degrees relative to the top surface 116. In one example, angle 130 may be between 175 degrees and 155 degrees. Further, the beveled edge 122 may be disposed at an angle 132 relative to the leading edge 112 or the trailing edge 114. The angle 132 may be greater than 90 degrees. In one example, the angle may be between 95 degrees and 115 degrees. In one other alternative example, the beveled edge 122 may be rounded, such as concave or convex.

Furthermore, the height of the beveled edge 122 may be such that the thickness of the leading edge 112 or trailing edge 114 meets control requirements. Thus, the thickness between the top surface 116 and the bottom surface 118 will necessarily be thicker than the thickness of the leading edge 112 or trailing edge 114 with the beveled edge 122. Further, the rounded transition 120 may be the minimum rounded edge that contacts the leading edge 112 or trailing edge 114 requiring control. In one example, the leading edge 112 or trailing edge 114 may be flat, perpendicular to the top and bottom surfaces 116, 118, with rounded transitions connecting the leading edge 112 and trailing edge 114 to the top and bottom surfaces 116, 118. Alternatively, it is contemplated that the leading edge 112 and trailing edge 114 are fully rounded.

The blade 110 including the beveled edge 122 provides improved blade efficiency and aerodynamic performance. Such as blades 110, may require less energy to move the air per unit volume, thereby increasing the overall efficiency of the fan. In addition, the flat bottom surface provides a traditional design aesthetic for the fan blade to cater to the consumer. Thus, efficiency may be improved without sacrificing the visual appeal of the ceiling fan or the blades themselves.

The blades and sections thereof described herein allow for an increase in the total flow volume of the ceiling fan, thereby allowing for an increase in efficiency while maintaining the aesthetic appearance desired by the consumer, with the unfinished bottom surface of the ceiling fan. More specifically, the curved transition 60, 82 provides an increased downward force on the air, which increases the overall volume of the airflow, while the flat upper and lower surfaces of the blades match conventional fan blade forms, providing a pleasant or attractive aesthetic to the user.

The various features, aspects, and advantages of the disclosure may be implemented in any arrangement of aspects of the disclosure, including, but not limited to, the technical solutions defined in the following enumerated aspects:

1. a blade for a ceiling fan having a fan motor for rotating the blade, the blade comprising a body having an outer surface extending in a spanwise direction between a root and a tip and in a chordwise direction between a first side edge and a second side edge, the outer surface having a top surface and a bottom surface, and at least one curved transition on the top surface having a curvature extending to at least one of the first side edge and the second side edge, the at least one curved transition having a chordwise length greater than any transition on the bottom surface.

2. A blade according to any of the preceding aspects, wherein the at least one curved transition is a first transition extending to the first side edge, and the blade further comprises a second transition between the first side edge and the flat lower portion.

3. The blade of any of the preceding aspects, wherein each of the first and second transition portions comprises an elliptical curvature, wherein a major axis of the elliptical curvature for the first transition portion is greater than a major axis of the elliptical curvature for the second transition portion.

4. A blade according to any of the preceding aspects, wherein the curvature defines a non-circular profile.

5. A blade according to any of the preceding aspects, wherein the at least one curved transition comprises a first transition at the junction of the first side edge and the flat upper portion and comprises a second transition at the junction of the second side edge and the flat upper surface, and the blade comprises a third transition at the junction of the first side edge and the flat lower surface and comprises a fourth transition at the junction of the second side edge and the flat lower surface.

6. The blade of any of the preceding aspects, wherein the curve is one of an ellipse, a hyperbola, a parabola, an nth root curve, a logarithmic curve, and combinations thereof.

7. A blade according to any of the preceding aspects, wherein the curvature is elliptical and has a long axis extending in a chordwise direction.

8. A blade according to any of the preceding aspects, wherein the curved portion is elliptical and has a minor axis parallel to one of the first and second side edges.

9. A blade according to any of the preceding aspects, wherein at least one curved transition is defined as being about 1 inch wide in the chordwise direction.

10. A blade according to any of the preceding aspects, wherein at least one curved transition extends between 5% and 40% of the chord wise width between the first side edge and the second side edge.

11. A blade according to any of the preceding aspects, wherein at least one transition extends to the tip along the first and second side edges and along the entire tip.

12. A blade according to any of the preceding aspects, wherein the transition extends along the entire first side edge.

13. A blade for a ceiling fan, the blade having a chordwise direction and comprising: a flat upper surface; a flat lower surface opposite the flat upper surface; a side edge having a width that separates the planar upper surface from the planar lower surface; and a first curved transition portion that transitions between the side edge and the flat upper surface, the first curved transition portion having a chordwise width that is greater than any transition portion located between the flat lower surface and the side edge.

14. A blade according to any of the preceding aspects, wherein the first curved transition has a curvature that is one of elliptical, hyperbolic, parabolic, cubic, logarithmic and combinations thereof.

15. A blade according to any of the preceding aspects, wherein the first curved transition comprises an elliptical curve.

16. A blade according to any of the preceding aspects, wherein the elliptical curvature does not define a circular profile.

17. The blade of any of the preceding aspects, further comprising a second curved transition between the side edge and the planar lower surface.

18. A blade according to any of the preceding aspects, wherein the second curved transition has a curvature that is one of elliptical, hyperbolic, parabolic, cubic, logarithmic and combinations thereof.

19. A blade according to any of the preceding aspects, wherein the first curved transition is defined wider than the second curved transition in a chordwise direction between the side edge and an opposite side edge of the blade.

20. A blade according to any of the preceding aspects, wherein the first curved transition extends around the circumference of the blade.

In the scope not yet described, the different features and structures of the individual features can be used in combination as desired. One feature is not shown in all aspects of the disclosure and is not meant to be construed as it cannot be shown in all aspects of the disclosure, but rather does so for the sake of brevity of description. Thus, the various features of the different aspects described herein may be mixed and matched as desired to form new features or aspects thereof, whether or not such new features or aspects are explicitly described. This disclosure will cover all combinations or permutations of features described herein.

This written description uses examples to detail aspects described in this disclosure, including the best mode, and to enable any person skilled in the art to practice the aspects described herein, including making and using any devices or systems or performing any incorporated methods. The patentable scope of the aspects described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Where these other examples have structural elements that do not differ from the literal language of the claims, or where such other examples include equivalent structural elements with insubstantial differences from the literal languages of the claims, they are intended to be within the scope of the claims.

Claims (12)

1. A blade for a ceiling fan having a fan motor for rotating the blade, the blade comprising:

a body having an outer surface extending in a spanwise direction between a root and a tip and extending in a chordwise direction between a first side edge and a second side edge, the outer surface having a planar top surface and a bottom surface, wherein the first side edge and the second side edge space the planar top surface from the bottom surface;

a top curved transition from the planar top surface to the first side edge; and

a bottom curved transition from the planar bottom surface to one of the first side edge and the second side edge;

wherein the top curved transition has a greater chordwise length than the bottom curved transition;

wherein the top curved transition and the bottom curved transition are one of an n-th root curve, a logarithmic curve, and combinations thereof.

2. The blade of claim 1, wherein the top curved transition is a first transition extending to the first side edge, and further comprising a second transition between the first side edge and the flat bottom surface.

3. The blade of claim 1, wherein at least one of the top curved transition and the bottom curved transition define a non-circular profile.

4. The blade of claim 1, wherein the top curved transition comprises a first transition at a junction of the first side edge and the planar top surface, and the blade further comprises a second transition at a junction of the second side edge and the planar top surface, and the bottom curved transition comprises a third transition at a junction of the first side edge and the planar bottom surface, and the blade further comprises a fourth transition at a junction of the second side edge and the planar bottom surface.

5. The blade of claim 1, wherein at least one of the top curved transition and the bottom curved transition is defined as being about 1 inch wide in the chordwise direction.

6. The blade of claim 1, wherein at least one of the top curved transition and the bottom curved transition extends between 5% and 40% of a chordwise width between the first side edge and the second side edge.

7. The blade of claim 1, wherein at least one of the top curved transition and the bottom curved transition extends to the tip along the first side edge and the second side edge and along the entire tip.

8. The blade of claim 1, wherein at least one of the top curved transition and the bottom curved transition extends along the entire first side edge.

9. A blade for a ceiling fan, the blade having a chordwise direction and comprising:

a flat planar upper surface;

a flat planar lower surface opposite the flat planar upper surface;

a side edge having a width that spaces the planar upper surface from the planar lower surface;

a first curved transition portion that transitions between the side edge and the planar upper surface; and

a second curved transition portion that transitions between the side edge and the planar lower surface;

wherein the first curved transition portion has a chordwise width that is greater than a chordwise width of the second curved transition portion;

wherein the first curved transition portion has a curved portion that is one of an n-th order root curve, a logarithmic curve, and a combination thereof.

10. The blade of claim 9, wherein the second curved transition has a curvature that is one of elliptical, hyperbolic, parabolic, cubic-n-root, logarithmic, and combinations thereof.

11. The blade of claim 10, wherein the first curved transition is defined to be wider than the second curved transition in a chordwise direction between the side edge and an opposite side edge of the blade.

12. The blade of claim 9, wherein the first curved transition extends around a periphery of the blade.