GB2281593A

GB2281593A - Fan blade.

Info

Publication number: GB2281593A
Application number: GB9318333A
Authority: GB
Inventors: Yung-Chung Huang
Original assignee: TYGAR CO Ltd
Current assignee: TYGAR CO Ltd
Priority date: 1993-09-03
Filing date: 1993-09-03
Publication date: 1995-03-08
Also published as: GB9318333D0

Abstract

A fan blade for a ceiling fan (40) (Fig. 3) comprises a plate 6 with a first end 64 to be fixed to a shaft, a second end 65, two edges (61) (Fig. 6) extending from the first end 64 to the second end 65, and two opposite faces 62. Each of the opposite faces 62 is indented gradually and inwardly from each of the peripheral edges 61 so as to form a substantially concaved surface and the blade may thin gradually from the first end to the second end. The blade shape enables lighter blades to be made which produce air-flow in more than one direction when rotated. <IMAGE>

Description

FAN BLADE This invention relates to a fan blade, more particularly to a blade of a ceiling fan.

Figure 1 shows a ceiling fan which has a rotary shaft unit that includes a motor 1 and a blade supporting frame 2 driven by the motor 1, and a plurality of blades 3 fixed inclinedly to the blade supporting frame 2 in order to induce air currents for enhancing air circulation when the blades 3 rotate.

Referring to Figure 2, each blade 3 is formed as a flat plate 31 which has two opposite flat surfaces 30 and a uniform thickness.

In order to prevent deformation of the blade 3 due to gravity and wind resistance, the blade 3 is made with a predetermined thickness. When the thickness of the blade 3 is reduced (i.e., smaller than the predetermined thickness) in order to reduce the weight thereof, the blade 3 may deform easily because it cannot bear the effects of gravity and wind resistance.

The deformed blade cannot induce efficiently air currents. Therefore, the conventional blade 3 is generally heavy, thereby making it inconvenient to mount on the blade supporting frame 2.

In addition, due to the flat surfaces 30 formed on the flat plate 31, the air currents which are produced when the blade 3 generally flow in only one direction.

Therefore, the objective of this invention is to provide an improved blade of a ceiling fan, which blade is lighter than the conventional blade and can produce air currents that flow in different directions when rotated.

Accordingly, a blade of this invention is to be mounted on a rotary shaft unit of a fan and has a plate with a first end to be fixed on the rotary shaft unit, a second end opposite to the first end, two opposite elongated peripheral edges extending from the first end to the second end, and two opposite faces, each of which being bounded by the first and second ends and the peripheral edges. Each of the two opposite faces is indented gradually and inwardly from each of the peripheral edges so as to form a substantially concaved surface.

The substantially concaved surface formed on each of the two opposite faces can include two opposed inclined portions and a valley portion at which the two opposed inclined portions are joined. Each of the opposed inclined portions may incline at an angle of about 4-6 degrees relative to a plane containing the peripheral edges. Furthermore, the plate of the blade can thin gradually from the first end toward the second end thereof.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a ceiling fan with conventional fan blades.

Figure 2 is a schematic view of the conventional fan blade.

Figure 3 is a schematic view of a ceiling fan provided with a first preferred embodiment of a fan blade of this invention.

Figure 4 is a side view of the first preferred embodiment of the fan blade of this invention.

Figure 5 is a sectional view of the first preferred embodiment.

Figure 6 is a top view of the first preferred embodiment.

Figure 7 is a sectional view of the first preferred embodiment showing an angle formed between an inclined portion and a plane containing the peripheral edges of a plate of the blade of this invention.

Figure 8 is a sectional view of a second preferred embodiment of the blade of this invention.

Figure 9 is a top view of the second preferred embodiment.

Figures 4 to 7 show a first preferred embodiment of a blade (A) of a ceiling fan 40 according to this invention. The ceiling fan 40, as shown in Figure 3, has a rotary shaft unit 50 which includes a motor 4 with a shaft 41 and a blade supporting frame 5 that is connected to the shaft 41 and that is driven rotatably by the motor 4. The ceiling fan 40 further has a plurality of blades (A) of this invention mounted inclinedly to the blade supporting frame 5. The blade (A) has a plate 6 with a first end 64 which is fixed to the blade supporting frame 50, a second end 65 opposite to the first end 64, two opposite elongated peripheral edges 61 extending from the first end 64 to the second end 65, and two opposite faces 62, each of which being bounded by the first and second ends 64, 65 and the peripheral edges 61.Each of the opposit'e faces 62 is indented gradually and inwardly from each peripheral edge 61 so as to form two opposed inclined portions 63 and a valley portion 63' at which the two opposed inclined portions 63 are joined. Referring to Figure 7, each of the opposed inclined portions 63 inclines at an angle (Y) of about 4-6 degrees relative to a phantom plane (P) containing the peripheral edges 61.

Referring again to Figure 4, the blade (A) can thin gradually from the first end 64 toward the second end 65.

Due to the formation of the inwardly indented faces 62 on the plate 6 of the blade (A), the blade (A) can bear the effects of gravity and wind resistance and does not deform easily when the thickness of the peripheral edge 61 of the blade (A) at the first end 64 is equal to the thickness of the conventional blade 3 while an intermediate portion, which is located between the peripheral edges 61, is thinner with respect to the peripheral edge 61. Furthermore, due to the formation of the inwardly indented faces 62, the blade (A) can be made to thin gradually from the first end 64 toward the second end 65 and can still bear the effects of gravity and wind resistance without deforming. In this way, when the blade (A) of the invention is made of a material which is similar to that of the conventional blade 3, the blade (A) weighs less.Therefore, it is more convenient to mount the blade (A) of this invention to the blade supporting frame 5. Since the blade (A) of this invention does not deform easily, it can induce efficiently air currents when rotated.

Since the plate 6 of the blade (A) is formed with opposed inclined portions 63 instead of flat surfaces, the air currents which are produced flow in different directions when the blade (A) rotates so as to enhance efficiently air circulation.

It is noted that the blade (A) can be rotated in a clockwise or anticlockwise direction to induce air currents when mounted on the ceiling fan 40. In addition, the blade (A) can be made to have a uniform cross-section without the reduced thickness which is formed gradually from the first end 64 toward the second end 65.

Figures 8 and 9 show a second preferred embodiment of the blade (B) of a ceiling fan according to this invention. The blade (B) has a plate 6' with a first end 64' to be fixed to a rotary shaft unit of a ceiling fan, a second end 65' opposite to the first end 64', two opposite elongated peripheral edges 61' extending from the first end 64' to the second end 65', and two opposite faces 62', each of which being bounded by the first and second ends 64', 65' and the peripheral edges 61'. Each of the two opposite faces 62' is indented gradually and inwardly from each peripheral edge 61' so as to form a substantially concaved surface 63'.

Claims

CLAIMS:

1. A fan blade to be mounted on a rotary shaft unit of a fan, comprising a plate with a first end to be fixed to said rotary shaft unit, a second end opposite to said first end, two opposite elongated peripheral edges extending from said first end to said second end, and two opposite faces, each of which being bounded by said first and second ends and said peripheral edges, at least one of said two opposite faces being indented gradually and inwardly from each of said peripheral edges so as to form a substantially concaved surface.

2. A fan blade as claimed in Claim 1, wherein said substantially concaved surface formed on said one of said two opposite faces includes two opposed inclined portions and a valley portion at which said two opposed inclined portions are joined.

3. A fan blade as claimed in Claim 2, wherein each of said two opposed inclined portions inclines at an angle of about 4-6 degrees relative to a plane containing said peripheral edges.

4. A fan blade as claimed in Claim 1, wherein said plate thins gradually from said first end toward said second end thereof.

5. A fan blade substantially as hereinbefore described with reference to Figures 3 to 9.