Description of the prior art According to the known art, seats of the type that has just been mentioned, having a conventional ring- shaped structure, are mounted in a fixed position on the toilet bowl and incorporate a certain number of spray nozzles. These nozzles are sustained by a box-type structure that stands on the rear part of the seat. The nozzles can completely moisten the upper surface of that seat, i. e. the surface affected by contact with the skin of the user. Following the spraying of the fluid, the same nozzles are used to provide an air stream for drying the seat.

The operation of the nozzles is controlled by a suitable electronic control system that, by means of appropriate sensors, is capable of establishing when a use has been terminated and, consequently, triggering the cleaning of the seat in view of the next use.

The sanitizing fluid, stored in a tank, is sprayed onto the seat with a certain abundance and a part of it therefore tends to drip from the seat edges, both inside

and outside the ring. While the dripping from the internal perimeter edge does not constitute a problem, since the sanitizing fluid ends up within the toilet bowl, the dripping from the outer perimeter edge causes a not negligible drawback. In fact, the whole external surface of the bowl is daubed by it, also because this part is not reached by the drying air jet. Apart from creating an unpleasant impression of lack of cleanliness, the user's clothing may be stained, this being undoubtedly annoying.

Summary of the invention The object of the present invention is therefore to solve the above problem by providing a new model of an automatically sanitized toilet seat that, thanks to an original configuration, is capable of avoiding, or at least hindering, the dripping of the sanitizing fluid onto the external surface of the toilet bowl.

This aim is attained by the automatically sanitized toilet seat according to the present invention, having a generally ring-shaped structure with an upper surface coming into contact with a user, said surface being defined between an external perimeter edge and an internal perimeter edge, the seat comprising or being associated with a multiplicity of spray nozzles for moistening said upper surface with sanitizing fluid. The seat is characterized by the fact that it comprises a passage formed so as to provide a fluid inlet opening along the external perimeter edge and a fluid outlet opening along the internal perimeter edge, the inlet opening being shaped in such a manner as to collect the excess fluid flowing over said external edge, whereby

said excess fluid is drained away into the toilet bowl through the passage and its outlet opening.

According to a preferred embodiment of the invention, the seat has a two-part construction with an upper and a lower part, that are mutually connected in a spaced manner so as to define said passage between them.

Advantageously, the lower part is substantially basin- shaped, thanks to the provision of an external peripheral lip that is bent obliquely upwards. Correspondingly, the upper part provides an external peripheral lip bent obliquely downwards and inwards, spaced from the lip on the lower part so as to form the inlet opening of the passage. Adhering to the surface of the external lip on the upper part, the sanitizing fluid enters the passage, dropping into the basin formed by the lower part and flowing towards the outlet opening.

Brief description of the drawings The characteristics and advantages of the automatically sanitized toilet seat in accordance with the present invention will be brought out more clearly by the description given hereinbelow of a particular embodiment thereof, which is to be considered as an example and not limitative in any way, said description making reference to the attached drawings in which: - figure 1 shows a perspective view of the entire toilet installation provided with a self-sanitizing seat according to the invention; - figure 2 shows an exploded perspective view of the seat according to the invention as seen from below; - figure 3 shows a top plan view of the seat of figure 2;

- figure 4 is a cross section of the seat taken along lines IV-IV of figure 3; and - figure 5 shows a front elevation of the seat of the previous figures.

Detailed description of a preferred embodiment Referring to figure 1, a seat according to the invention, indicated by the reference number 1, has a conventional ring-shaped structure with an upper surface la, which will come into contact with a user, defined between an external perimeter edge lb and an internal perimeter edge 1c. Conventionally again, the seat is arranged above a bowl 2 of a water closet. Still in conformity with the prior art, from the rear part of seat 1, i. e. the part where the back of the user will come to be positioned, there rises a box-like structure 3 of which a front wall 3a bears several nozzles 4 capable of flushing said upper surface la of seat 1 with a sanitizing fluid and thereafter providing an air stream so as to dry said surface again.

The box-like structure 3 houses the water and air circuits that feed nozzles 4. Above structure 3 there is arranged a case 5 within which there is situated, besides the traditional tank containing the bowl-flushing water, the electronic system that controls the operation of nozzles 4 in response to a signal emitted by appropriate sensor means. Said means, as known to persons skilled in the art, are capable of detecting the end of each individual use of the water closet and, consequently, activating the sanitizing operation.

Referring now also to the other figures, according to the invention external edge 1b and internal edge lc of seat 1 are communicated with each other via a passage 6

formed within seat 1. In greater detail, passage 6 is preferably obtained, as in the illustrated embodiment, by realizing seat 1 with a two-part construction. In fact, a lower part 12 that rests on the toilet bowl 2 underlies an upper part 11 that comprises, over and above the box- like structure 3, the upper surface la with the external perimeter edge 1b and the internal perimeter edge lc.

As can be seen particularly well from figure 2, the two parts of the seat are mutually connected by means of U-shaped stirrups 7 that extend downwards from the upper part 11 and are arranged at substantially equal distances along the ring of the seat. Stirrups 7 engage with fixing screws (not shown on the drawing) that pass through appropriate seatings 8 formed in the lower part 12. The fact that the two parts of the seat are kept apart by stirrups 7 does generate passage 6.

Turning now to figure 4, it can be seen that the lower part 12, along the external perimeter, is provided with a lip 12a that is bent obliquely upwards, thus conferring upon said part a shape that generally corresponds to a basin. Similarly, on the upper part 11 there is provided an external perimeter lip lla that is bent obliquely downwards and towards the interior of the seat. Said lip thus projects into the basin defined by the lower part 12, though it remains at a certain distance from lip 12a so as to form an inlet opening of passage 6.

Along its internal perimeter, on the other hand, lower part 12 is provided with a downward-pointing lip 12b. The upper part 11, in its turn, is provided with an internal perimeter lip lib that extends vertically downwards and, in cooperation with the internal perimeter

lip 12b of the lower part 12, forms an outlet opening of passage 6, facing the inside of bowl 2 of the water closet.

Thanks to the configuration just described, when after a use nozzles 4 spray sanitizing fluid onto the upper surface of seat 1, the excess fluid flowing over the external edge lb, rather than dripping onto the outer surface of toilet bowl 2, is collected within passage 6 and thence drained away into the inside of the bowl.

In fact, due to the surface adhesion effect, the fluid descends along the external lip lla of the upper part and thus pass through the inlet opening of hollow space 6. Dripping off the margin of lip lla, is collected by lip 12a of the lower part 12 and then conveyed towards the internal perimeter of the seat, that is to say, towards the outlet opening of passage 6. Passing through this opening, it drops into the toilet bowl. With a view to facilitating the discharge of the fluid, the bottom of lower part 12 may advantageously slope slightly downwards as it passes from external lip 12a to internal lip 12b.

This arrangement assures that the outer surface of bowl 2, as also the surrounding floor, remain dry, thus giving a pleasant impression of order and cleanliness, avoiding also all possibility of the user's clothes becoming wetted and/or soiled. It is therefore evident that the seat in accordance with the invention, though employing a structure of extreme simplicity, provides a perfectly efficient solution of a rather annoying problem.

Passage 6 that collects the sanitizing fluid and conveys it from the external perimeter to the internal perimeter of the seat can obviously be realized by means

of different constructions from the two-part one described and illustrated above. The two-part construction of the seat may however prove advantageous on account of its simplicity, and can also be exploited to associate heating means with the seat or-more precisely-with its upper part 11. Said heating means, in the form of electrical resistances which are not shown on the drawings, will heat the upper surface la of the seat to a temperature of about 30°C and will therefore cause the evaporation of any traces of humidity that may have remained after the passage of the air stream, with the result that users will always find a perfectly dry seat.

Though particular reference has here been made to water closets of railway carriages, the self-sanitizing seat in accordance with the invention can of course be employed also in any toilet facility provided for public use in which problematics similar to the one describe hereinabove may arise.

Variations and/or modifications can be brought to the automatically sanitized toilet seat incorporating means for collecting the sanitizing fluid in accordance with the present invention without departing from the scope of the invention as defined by the attached claims.