GB2240621A - Ventilating fan - Google Patents

Abstract

A ventilating fan includes a casing (1) enclosing an electric motor (2) having a rotational shaft, a fan blade (4) detachably coupled to the rotational shaft of the motor (2), and a front frame (10) detachably attached to the front side of the casing (1). In the ventilating fan, either one or both of the fan blade (4) and the front frame (10) are formed from a foaming material such as foam polystyrene. Alternatively, either one or both of the fan blade (4) and front frame (10) may be formed from a sheet material or paper. In the event of either a fan blade or the front frame becoming soiled, the respective parts are easily replaceable. <IMAGE>

Description

VENTILATING FAN This invention relates to ventilating fans wherein either or both of a fan blade and a front frame which are likely to be soiled during a ventilating operation and are conspicuous are composed as throwaway parts and replaceable by respective new ones.

Ventilating fans are generally used for exhausting filthy air in a room or lamp smoke or soot induced in a kitchen. Since lamp dust or the like contained in the soot adheres to a fan blade and front decorative frame of the ventilating fan, the fan blade and front frame are gradually rendered dirty and the ventilating fan appearance is defiled. For preventing the fan blade and front frame from becoming dirty, they need to be periodically cleaned.

However, the lamp dust adherent to the surfaces of fan blade and front frame cannot be completely wiped away with a dustcloth or the like and accordingly, the fan blade and front frame are usually detached from the frame of the ventilating fan and washed in water. It is thus troublesome to wash the fan blade and front frame in water at every time of the cleaning.

For improvement of the above-described troublesome cleaning, a strippable paint has recently been applied to the surfaces of the fan blade and front frame such that paint films are formed thereon. In this case, the paint films are stripped away every time the fan blade and the front frame become dirty. Furthermore, a filter is attached to the front of the ventilating fan so that the lamp dust or the like is collected by the same.

However, in the case of forming strippable paint films, it takes much time for a user to apply a paint to the surfaces of the fan blade and front frame to thereby form uniform paint films thereon. Furthermore, the paint film thickness is liable to be ununiform and torn when stripped away. Thus, the paint film applying work is troublesome.

In the case of attaching a filter to the front side of the ventilating fan, it would be impossible to completely collect the lamp dust with the filter. Consequently, adherence of the lamp dust or the like to the fan blade and the front frame is unavoidable even when the filter is attached to the front of the ventilating fan. Thus, the cleaning efficiency cannot be completely improved by attachment of the filter to the front of the ventilating fan.

Therefore, an object of the present invention is to provide a ventilating fan wherein the cleaning efficiency may be improved.

The present invention provides a ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of the motor, and a front frame detachably attached to the front side of the casing, at least one of the fan blade and the front frame being formed from a foaming material.

Since either one or both of the fan blade and the front frame are formed from the foaming material, the production costs of the fan blade and the front frame are low and accordingly, the user may obtain a new fan blade and a front frame as throwaway parts at low costs for the purpose of replacement. What the user have to do at the time of the cleaning is to detach either or both of the fan blade and the front frame from the ventilating fan and to attach the respective new ones to the ventilating fan. Since the soiled fan blade and front frame are replaced by respective new ones, soil affixed to the fan blade and front frame may be completely removed therefrom and the appearance of the ventilating fan may be prevented from being defiled.

The invention may be practiced by a ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of the motor, and a front frame detachably attached to the front side of the casing, at least one of the fan blade and the front frame being formed from a sheet material.

As in the case of the foaming material, the sheet material may be obtained at low cost and either the fan blade or the front frame may be provided as a throwaway part.

Furthermore, the invention may be practiced by a ventilating fan comprising a casing enclosing an electric motor having a rotational shaft1 a fan blade detachably coupled to the rotational shaft of the motor, and a front frame detachably attached to the front side of the casing, at least one of the fan blade and the front frame being formed from paper.

As in the foaming and sheet materials, the paper may be obtained at low cost and either the fan blade or front frame may be provided as a throwaway part.

Furthermore, the invention may be practiced by a ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of the motor, and a front frame detachably attached to the front side of the casing, at least one of the fan blade and the front frame comprising a base material formed from either a foaming material or paper and a film applied to the surface of the base material.

In the case of the above-described construction, either the fan blade or the front frame may be provided as a throwaway part and replaceable. Additionally, since the base material may be reinforced by the film, the base material may be prevented from being broken during transportation, attachment and use thereof.

The invention will be described, merely by way of example, with reference to the accompanying drawings, in which: FIG. 1 is a longitudinal cross sectional view of a ventilating fan of a first embodiment of the present invention; FIG. 2 is a longitudinal cross sectional view of a ventilating fan of a second embodiment of the invention; FIG. 3 is a perspective view of a fan blade employed in the ventilating fan of the second embodiment; and FIG. 4 is a longitudinal cross sectional view of a ventilating fan of a third embodiment.

The ventilating fan of the first embodiment will now be described with reference to FIG. 1. A casing 1 of the ventilating fan is mounted on a wall (not shown) of the kitchen, for example. The casing 1 encloses an electric motor mounted on a mounting frame 3. The motor 2 has a rotational shaft (not shown) forwardly extended and a fan blade 4 is detachably coupled to the drive shaft by a nut 5.

The casing 1 has a rear opening to which three shutter members 6 are attached for rotative movement. The upper ends of the shutters 6 are coupled to a generally L-shaped lever 7 which can be lifted and lowered. A switch box 8 is disposed at the lower side of the casing 1. When a switch string 9 hung down on the switch box 8 is manually drawn, the L-shaped lever 7 is lowered, thereby opening the shutter members 6. Simultaneously, the motor 2 is energized to thereby drive the fan blade.

A front frame 10 is detachably attached to the front side of the casing 1. The front frame 10 has a bellmouth 11 formed so as to surround the fan blade 4. The front frame 10 also has a flange portion 10a formed on the external periphery thereof so as to extend backwardly. The flange portion 10a has an engagement projected portion 12 formed on the rear end inner periphery thereof. An elastic engagement strip 13 is formed on the front end flange la of the casing 1 so as to be projected forwardly and correspond to the engagement projected portion 12. The front frame 10 is detachably attached to the front side of the casing 1 by engaging the engagement projected portion 12 with the elastic engagement strip 13.

In the embodiment, the fan blade 4 and front frame 10 are formed in accordance with one of the following methods for the purpose of lowering the production costs thereof and being displaceable: 1) The fan blade 4 and the front frame 10 are formed by foaming a foaming material such as a foam polystyrene or from a foaming material sheet by way of the vacuum forming.

These foam products need less amount of material than the prior plastics products formed by way of the injection molding. Consequently, the material cost and therefore, the production cost may be lowered to a large extent.

2) The fan blade 4 and the front frame 10 are formed from a sheet material such as a polypropylene sheet by way of the vacuum forming, blow molding, hot press forming or the like. The forming process in each of these methods is simplified as compared with the prior injection molding, which reduces the forming cost. Furthermore, the thickness of the sheet material is reduced and consequently, the material cost is also reduced. Thus, the production cost may be reduced to a large extent.

3) The fan blade 4 and the front frame 10 are formed from paper by way of pressing. The paper may be obtained at low cost and the pressing does not require high forming cost. As a result, the production cost may be reduced to a large extent.

When the fan blade 4 and the front frame 10 are soiled, the front frame 10 is detached from the casing 1 by disengaging the engagement projected portion 12 from the elastic engagement strip 13 and then dumped away. Further, the nut 5 is disengaged so that the soiled fan blade 4 is detached from the drive shaft of the motor 2 and dumped away. Then, the new fan blade 4 and front frame 10 are attached to the ventilating fan. Such a replacement is rendered possible for the reasons that the foaming material, sheet material and paper may be obtained at low costs and that the production costs of the fan blade 4 and front frame 10 are low. Accordingly, in the ventilating fan of the embodiment, the fan blade 4 and front frame 10 need not be washed in water every time the ventilating fan is to be cleaned.Further, such a troublesome work as applying the strippable paint to the fan blade 4 and front frame 10 is not needed and the ventilating fan is free from the problems of occurrence of ununiform thickness of the paint and tear of the paint in the case where the paint is stripped. Thus, the cleaning of the ventilating fan may be done by replacing the soiled fan blade 4 and front frame 10 with respective new ones. Since the nut 5 fixing the fan blade 4 to the motor shaft is positioned on the center of the fan blade 4 and air flows along the external peripheral sides of the fan blade 4, the nut 5 does not relatively become dirty.

Further, the nut 5 may be cleaned with ease and accordingly, the nut 5 need not be a throwaway part.

Furthermore, since the fan blade 4 and front frame 10 which are conspicuous are replaced by the respective new ones every time the ventilating fan is cleaned, the appearance of the ventilating fan may be maintained at that of the new one and the stains adherent to the portion of the ventilating fan seen at the room interior may be completely removed away.

Furthermore, since the fan blade 4 and front frame 10 are formed from the foaming material, sheet material or paper all of which are relatively low in durability, the fan blade 4 and front frame 10 may be broken into pieces with ease when they are dumped. Thus, the fan blade 4 and front frame 10 are not bulky and may be collected as wasted articles with ease.

It is more or less inevitable that the durability of each of the fan blade 4 and front frame 10 is lowered as compared with those of the prior art. However, since these parts may be replaced by new ones in the ventilating fan of the present invention, the durability of each of these parts is not required to be so high that they are durable for a sufficient long period as in the prior art ventilating fans.

Accordingly, the durability of each of the fan blade 4 and front frame 10 is only required to be at such a level that they durable for a relatively short period from the start of use to the time they become dirty. Such a level of durability may be sufficiently obtained from the foaming material, sheet material or paper. Moreover, the fan blade 4 and front frame 10 formed from these materials weigh light. Should these parts fall off during operation of the ventilating fan, that would not cause any injury to persons.

Additionally, since employment of the light-weight fan blade 4 improves unbalance thereof, the vibration and therefore, noise generated during the ventilating operation may be reduced.

FIGS. 2 and 3 illustrates the ventilating fan of a second embodiment. The second embodiment differs from the foregoing embodiment in that the fan blade 14 and front frame 15 comprise a bases 14a and 15a formed from the foaming material or paper and films 14b and 15b affixed to the surfaces of the bases, respectively. In production of the fan blade 14 and front frame 15, a film 14b or 15b such as a polyester film is laminated or otherwise affixed to the surface of a foaming material or paper sheet 14a or 15a by adhesive. Subsequently, the fan blade 14 and front frame 15 are formed from the foaming material or paper sheet with the film affixed thereto by way of the vacuum forming.

The same effect is achieved in the second embodiment as in the foregoing embodiment and additionally, the following effect is achieved in the second embodiment. The bases 14a and 15a of the fan blade 14 and front frame 15 may be reinforced by films 14b and 15b, respectively, thereby preventing them from being damaged during transportation, mounting and use. Furthermore, the films 14b and 15b may be colored with ease and a desirable marking or figure may be printed on the films 14b and 15b with ease, thereby improving design of the-ventilating fan.

FIG. 4 illustrates the ventilating fan of a third embodiment. A filter 16 is attached to the front frame 10 so as to cover the bellmouth 11. The filter 11 is utilized to collect the lamp dust in the exhaust air. The filter 16 includes a frame 16a having generally L-shaped hook arms 17 projected toward the rearward of the ventilating fan. The L-shaped hook arms 17 are inserted into holes 18 formed in the front frame 10, respectively to be engaged with the front frame. At the time of the cleaning, the front frame 10 and filter 16 are simultaneously replaced by new ones, respectively.

In the third embodiment, since the lamp dust in the air may be collected by the filter 16, the progress of dirtiness of the fan blade 4 and front frame 10 may be retarded, thereby reducing the number of times of replacement of these parts. Consequently, the parts replacement cost may be reduced. Furthermore, since the lamp dust in the air may be collected by the filter 16, the degree of dirtiness of an outdoor side wall due to the lamp dust may be reduced to a large extent.

Although both of the fan blade and front frame are replaced by new ones in the foregoing embodiments, either one of them may be replaced.

The foregoing disclosure and drawings are merely illustrative of the principles of the present invention and are not to be interpreted in a limiting sense. The only limitation is to be determined from the scope of the appended claims.

Claims (5)

WHAT WE CLAIM IS:

1. A ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of said motor, and a front frame detachably attached to the front side of said casing, at least one of said fan blade and said front frame being formed from a foaming material.

2. A ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of said motor, and a front frame detachably attached to the front side of said casing, at least one of said fan blade and said front frame being formed from a sheet material.

3. A ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of said motor, and a front frame detachably attached to the front side of said casing, at least one of said fan blade and said front frame being formed from paper.

4. A ventilating fan comprising a casing enclosing an electric motor having a rotational shaft, a fan blade detachably coupled to the rotational shaft of said motor, and a front frame detachably attached to the front side of said casing, at least one of said fan blade and said front frame comprising a base material formed from either a foaming material or paper and a film joined to the surface of said base material.

5. A ventilating fan substantially as herein described with reference to the accompanying drawings.