This invention relates to a device intended to be placed inside appliances that draw air with the use of fans, in this specific case hairdryers, both portable and fixed. More specifically, this invention relates to a device, as defined above, formed by a plastic (PA polyamide) or metal structure that combines a hollow body, which houses in its interior the rotating motor shaft on which is fixed the propeller/fan of the appliance in which the device is installed, and by a structure formed by two other hollow cylinders with larger diameters - of different sizes and thicknesses depending on the recipient appliance - suitable to support the hollow body. Thus the device comprises: a hollow body joined by the structure formed by two concentric cylinders that present the anchoring flanges to the appliance, and the convectors necessary to operate as spokes between the two concentric cylinders of different diameters and as effective air conveyors. The purpose of this invention is to avoid the drawbacks caused by dirt drawn inside the appliance with the air. More specifically, the purpose of this invention is to provide a device which can protect the motor shaft of appliances with rear suction and axial fan from dirt drawn inside the appliance by the fan and to divert the air flows sucked in to stop the vacuum thus generated internally, especially around the motor shaft, to avoid and prevent dirt from accumulating around the said shaft. An additional purpose of the invention is to provide a device, as defined above, which, thanks to the guaranteed internal cleaning, can improve and ensure longer motor life by allowing a continuously optima! and constant rotation, and thus a higher efficiency of the appliance. A further purpose of the invention is to provide a device suitable to reduce the thickness of the outer shell of the appliance, since the structural function of the flanges and/or of the conveyors can possibly also create an internal connection that strengthens and stiffens the structure of the specific appliance to which it is anchored. Finally, the anchoring of the device at several points ensures not only that it remains equidistant and centred with respect to the motor shaft, but provides also increased resistance to blows. These and other purposes are achieved by the "protection device to avoid the deposit of dirt inside the hairdryer and conveyor of air flows for the optimization of the devices". To the knowledge of the inventor, the current state-of-the-art of hairdryers does not include the use of devices such as that represented by this invention to protect the motor shaft and to create a rationalised outflow of the airflows internally. There are inventions with the purpose of providing the outflow of dirt in different ways, using separators of the air drawn inside to direct it towards the discharge areas of the collected dirt, referred to in the patent published under number 20030140788 B2 of 31 July 2003. Another invention referred to in the patent published in Germany as DE 19834376 A1 generates a cyclonic flow in the motor. The innovation of the device of this invention is given by the coverage and envelopment of the motor shaft with a single hollow plastic (PA polyamide) or metal body, in turn supported by a structure of the same materia! that includes the anchoring flanges to the inner body of the hairdryer or the fan, and the conveyors (walls parallel to the air flow generated by the fan inside the appliance) that operate as air convectors and deflectors, pre-stamped and fixed in the structure, which can be set at the different angles desired, capable of eliminating the air depressions that cause dirt accumulation inside the appliance and reduced performance. At that point, the dirt in the air is expelled directly from the device without clogging or damaging the motor shaft.

The constructive and functional characteristics of the device of this invention can be more clearly understood from the following detailed description, wherein reference is made to the attached tables of drawings that illustrate a preferred but not limiting manner of constructing the said device and in which:

Figure 1 schematically represents, in perspective view, the entire body of the device of this invention which by way of example includes: a) the hollow cylindrical body enveloping the motor shaft; b) the two concentric hollow cylinders of different diameter that form the structure that supports and houses the hollow cylindrical body, as well as the flanges and the conveyors; c) the conveyors which function as spokes to bind together the two concentric cylinders and as air deflectors; Figure 2 schematically represents the vertical cross-section of the same device that specifically highlights the elements which in this example form the frame and the anchorage of the hollow cylindrical body to the structure; Figure 3 schematically represents the cross-section of the appliance where the device of the invention is shown already fitted inside to show an example of its positioning and of the air flows created, with the indication, at the centre, of the hollow cyiindrical body that envelops the motor shaft; Figure 4 schematically represents, in perspective view, the entire body of the device of the present invention with the detail of the hollow cylindrical body (Zone C), the motor shaft, the flanges and the conveyors, and of the area intended for the mechanical support of the device for anchorage to the motor; Figure 5 schematically represents the vertical cross-section of the same device that specifically highlights the elements which in this example form the frame and the anchorage of the hollow cylindrical body; Figure 6 schematically represents the horizontal cross-section of the same device that specifically highlights the elements which in this example form the frame, the structure of the body which anchors the hollow cylindrical body to the appliance, as well as the connecting flanges and the conveyors for the related functions of structural spoke and of intake air diverters. A device that comprises a part called hollow body (Figure 1 element a) or Figure 3 element C) with functions of bearing and/or bushing inserted onto the motor shaft of the electric motor on which the fan and/or propeller that draws air from outside towards the body of the hairdryer is fitted. A device that includes another part or structure which anchors the hollow cyiindrical body to the flanges, and the other part of the structure which houses the conveyors that deflect and direct the air flows into the desired areas within the appliance, and which also has structural purposes as spoke between the two concentric cylinders that anchor and support the hollow cylindrical body of the device to the appliance. The part of the device that envelops the motor shaft, the hollow body, can be made also in other ways than that shown, which corresponds to a stand-alone cylinder that is clamped or fixed directly on the motor flange, as shown in the figure. In fact, the hollow body may have a conical, faceted or square shape. The internal part, however, has a cylindrical shape so as to envelop the motor shaft (Zone C in Figure 4). The length of the hollow body is variable, since it can continue up to the partial correspondence/insertion of the fan, but it will be for the entire length of the motor shaft of the appliance so as to cover it fully up to both ends, completely isolating the area concerned from any possibility of dirt infiltration. The external structure of the device has plastic or metal sides, resistant to high temperatures. Specifically, the device comprises: a hollow body joined together by the structure formed by two concentric cylinders that present the anchoring flanges to the appliance, and the conveyors necessary to operate as spokes between the two concentric cylinders with different diameters. On top of the cylinder with the narrower diameter is the conjunction with two or more arms useful to support or bind the hollow body to this structural part, while on its opposite part it has the flanges necessary to anchor the device to the internal body of the appliance or to the motor or to the fan. The two concentric cylinders are joined together by the conveyors that have the structural functions of a spoke useful for joining together the two concentric cylinders and possibly for supporting the entire device on the internal shell of the appliance. The conveyors also perform a functional activity since they direct the air outflow. The flanges are that part of the device which together with the conveyors not only perform the function of conveying and directing the air flows drawn in by the fan in order to avoid the generation of depressions as far as possible and to allow maximisation of the air flows in terms of both flow rate and pressure, but also a structural function of anchorage to the internal body of the appliance. Should the flanges solution, as shown in Figures 1 and 4, be adopted, the support of the hollow cylindrical body of the device will have a structural function since the flanges and the air conveyors will also have the function of mechanical support for anchorage to the shell that forms the appliance in question or to the motor. The methods of the structure of the device are indeed irrelevant, since the invention consists in having devised a protective body around the motor shaft, together with a structure that can be made in different manners and that has the function of deflecting the generated airflows. Possible developments of the Invention: developments of the invention relate to the ways of anchoring the device, or rather its hollow body, to the appliance. In fact, the hollow cylindrical body can be an integral part of the suction fan or it can be mounted on its structure as shown in the attached figures. Although the invention has been described above with particular reference to one of its forms of construction, given by way of example and limited to that, numerous modifications and variations will be apparent to experts of the branch in light of the foregoing description. This invention, therefore, intends to encompass all modifications and variations that fall within the spirit and the protective scope of the following claims.