1. Field of the Invention
The present invention relates to a smoke exhauster, and more particularly to a smoke exhauster including an improved fan device for increasing the air drawing effect thereof and for reducing the noise that may be generated by the smoke exhauster.
2. Description of the Prior Art
The applicants have developed various kinds of typical smoke exhausters which comprise one or more centrifugal fan devices each having a fan casing and a number of radially extended fan blades directly punched or forged or extended from the fan casing.
For example, U.S. Pat. No. 5,158,429 to Chiang et al. discloses one of the typical smoke exhausters comprising a number of radially extended fan blades directly punched or forged or extended from the fan casing for agitating the air or the like and for generating a circulating air. Due to the directly punching or forming of the fan blades from the fan casing, the fan blades may only be formed with a single curvature and may include a limited or a small area for actuating the air.
For increasing the air drawing effect to the fan device, the applicants have further developed various kinds of typical smoke exhausters comprising a fan device including a number of preformed fan blades to be assembled and secured between two casing members for increasing the air drawing effect to the fan devices.
For example, U.S. Pat. No. 6,866,481 to Chiang et al., and U.S. Pat. No. 6,945,753 to Chiang et al. discloses two of the typical smoke exhausters each comprising a fan device including a number of preformed and curved and suitably shaped fan blades to be assembled and secured between an upper plate and a lower plate for increasing the air drawing effect to the fan devices.
However, the fan blades include a solid structure that may generate a great noise particularly when the fan blades are rotated or driven or operated in a great speed.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional smoke exhausters.
The primary objective of the present invention is to provide a smoke exhauster including an improved fan device for increasing the air drawing effect thereof and for reducing the noise that may be generated by the smoke exhauster.
In accordance with one aspect of the invention, there is provided a fan device for a smoke exhauster comprising a housing including an upper plate, and a lower plate disposed below the upper plate for forming a chamber between the upper plate and the lower plate, the upper plate including a number of slits formed therein, the lower plate including a number of slots formed therein, and including a bore formed therein, and the upper plate including a casing provided therein, the chamber of the fan device being communicating with the bore of the lower plate to allow an air to flow through the bore of the lower plate and to flow into the chamber of the fan device, a motor received in the casing of the upper plate and including a spindle secured to the casing of the upper plate of the housing for allowing the casing of the housing to be rotated and driven by the spindle of the motor and to be rotated relative to the motor, and a number of fan blades disposed in the chamber which is formed between the upper plate and the lower plate of the housing, the fan blades each include an upper portion having a number of ears extended upwardly therefrom and engaged through the slits of the upper plate for securing the fan blades to the upper plate, and each include a lower portion having a number of ears extended downwardly therefrom and engaged through the slots of the lower plate for securing the fan blades to the lower plate and for securing the fan blades between the upper plate and the lower plate, and the fan blades each include a curved bottom edge curved inwardly and upwardly from the lower plate toward the upper plate to allow the air to flow into the chamber of the fan device before contacting with the fan blades, and the fan blades each include a number of orifices formed therein for allowing the air to flow through the orifices of the fan blades and for reducing a noise generated by the fan blades when the fan blades are rotated relative to the motor.
The fan blades each includes a curved outer segment, and a planar inner segment. The fan blades are preferably disposed inclined relative to the upper plate and the lower plate for increasing an air scooping effect of the fan blades.
Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.
Referring to the drawings, and initially to
The motor 30 may further include a frame or bracket 32 (
The lower plate 20 includes a bore 22 formed therein (
The fan blades 40 may thus be solidly attached and secured between the outer peripheral portion of the upper plate 11 and the lower plate 20. As shown in
The fan blades 40 of the housing 10 of the fan device 1 each further include a number of orifices 48 formed therein for allowing the air to flow through the orifices 48 of the fan blades 40 and for reducing the noise that may be generated by the fan blades 40 when the fan blades 40 are rotated or driven or operated in a great speed. The fan blades of the typical fan devices have no noise reducing orifices formed in the fan blades such that the fan blades of the typical fan devices may generate great noises particularly when the fan blades are rotated or driven or operated in a great speed. It is to be noted that a single fan device 1 has been shown and illustrated in
It is further to be noted that the fan blades 40 are shown in the drawing figures to be secured between the upper plate 11 and the lower plate 20, and the fan blades 40 may be disposed or arranged perpendicular to the upper plate 11 and the lower plate 20, or the fan blades 40 may be arranged or disposed to be tilted or inclined relative to the upper plate 11 and the lower plate 20, best shown in
The formation or provision of the orifices 48 in the fan blades 40 allows the air to flow through the orifices 48 of the fan blades 40 and to reduce the noise that may be generated by the fan blades 40, and the inclination of the fan blades 40 relative to the upper plate 11 and the lower plate 20 may further increase the air drawing or scooping effect of the fan blades 40.
Accordingly, the smoke exhauster in accordance with the present invention includes an improved fan device for increasing the air drawing effect thereof and for reducing the noise that may be generated by the smoke exhauster.
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.