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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a self-cleaning public toilet and to the corresponding safety equipment. 
         [0003]    More in particular, the present invention regards a self-cleaning public toilet in which washing and drying of the toilet is carried out automatically after each individual use. 
         [0004]    2. Description of the Related Art 
         [0005]    In towns, there is a more and more widespread use of self-cleaning public toilets to be installed in a fixed way in public places, or else in a removable way on the occasion of events (sports events, concerts, etc.) in which large crowds of people gather. 
         [0006]    In the past, the use of self-cleaning toilets of this type has highlighted different problems, which can be summarized as follows: 
         [0007]    (1) the systems of cleaning and drying are costly and difficult to maintain; 
         [0008]    (2) the toilet systems are subject to frequent acts of vandalism, which considerably raise the costs of management thereof; and 
         [0009]    (3) the toilet systems do not respect effective rules as regards safety, both in terms of the aspects regarding safe opening of the exit door or as regards possible moving devices within the toilet itself. 
         [0010]    In effect, in the past, there have occurred events, including even tragic ones, in which the exit door failed to open for a wide range of reasons, or else the users were injured by mobile washing devices present inside the self-cleaning toilet. 
         [0011]    All of the above problems have merely had the effect of discouraging many potential users from using this type of toilets, both because they consider them not very clean, and because not they do not deem them altogether reliable from the safety standpoint. 
         [0012]    A kind of self-cleaning toilet is known from the document No. WO 95/30801 (SELF-CLEANING ENVIRONMENTS USA, INC.). The system described in this document envisages a wall-mounted articulated rotary arm that can move angularly along vertical/horizontal planes from a resting position, in which it is mounted in a wall, to a position of activation, in which it is set above a sanitary appliance to be washed. The rotary washing arm enables diffusion of the liquid from nozzles for cleaning the sanitary appliances. In addition, said rotary arm can be pre-arranged for describing a pre-set path around an area of interest. 
         [0013]    Even though the system described in WO/95/30801 has yielded certain appreciable results in the cleaning of sanitary appliances, it is deficient as regards the aspect of safety. In fact, in this system no device is provided for stopping the rotary washing arm in the case where it were to encounter, during its rotation, an obstacle along its path. 
       SUMMARY OF THE INVENTION 
       [0014]    Consequently, forming the main subject of the present invention is to provide a self-cleaning toilet that is not only simple to manage, but is also very safe for users. 
         [0015]    Provided, therefore, according to the present invention is a self-cleaning toilet with the corresponding safety equipment as claimed in the attached Claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The present invention will now be described with reference to the annexed drawings, which illustrate a non-limiting example of embodiment thereof and in which: 
           [0017]      FIG. 1  illustrates a plan view of a self-cleaning toilet forming the subject of the present invention; 
           [0018]      FIG. 2  shows a first layout of the self-cleaning toilet of  FIG. 1 ; 
           [0019]      FIG. 3  illustrates a second layout of the self-cleaning toilet of  FIG. 1 ; 
           [0020]      FIG. 4  shows a third layout of the self-cleaning toilet of  FIG. 1 ; 
           [0021]      FIG. 5  illustrates a fourth layout of the self-cleaning toilet of  FIG. 1 ; 
           [0022]      FIG. 6  shows a rotary washing arm in a closed position; 
           [0023]      FIG. 7  illustrates the rotary washing arm of  FIG. 6  in a partially open position; 
           [0024]      FIG. 8  shows the rotary washing arm of  FIG. 6  in a totally open position; 
           [0025]      FIG. 9  illustrates a first part of a block diagram corresponding to the safety system of the self-cleaning toilet of  FIGS. 1 ,  2 ,  3 ,  4  and  5 ; and 
           [0026]      FIG. 10  shows a second part of a block diagram corresponding to the safety system of the self-cleaning toilet of  FIGS. 1 ,  2 ,  3 ,  4  and  5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    In  FIGS. 1 ,  2 ,  3 ,  4  and  5 , designated as a whole by  10  is a self-cleaning toilet forming the subject of the present invention. 
         [0028]    The self-cleaning toilet  10  comprises a substantially parallelepipedal load-bearing structure  11 , obtained with traditional systems. 
         [0029]    The load-bearing structure  11  delimits, with its walls  12 ,  13 ,  14 , and  15 , an internal space RM of use designed to house the toilet facilities, as will be described hereinafter. 
         [0030]    In fact, the internal space RM houses in a known way a toilet bowl  16 , set up against the wall  13 , and a wash-basin  17 , resting on the wall  15  opposite to the wall  13 . 
         [0031]    The load-bearing structure  11  is equipped with a hydraulic technical space HTS external to the space RM and in effect constituting the aforesaid wall  15 . The hydraulic technical space HTS is designed to contain hydraulic equipment (not illustrated), which has the purpose of sending water to the toilet bowl  16 , to the wash-basin  17 , and to the washing system (see hereinafter). 
         [0032]    The hydraulic technical space HTS is closed by a main door D 1 , which can be opened only from outside the toilet  10 . 
         [0033]    Housed in an electrical and pneumatic technical space EPTS, in effect constituting the wall  13 , is electrical and pneumatic equipment (not visible) necessary for operation of the self-cleaning toilet  10  (see hereinafter). 
         [0034]    The electrical and pneumatic technical space EPTS is closed by a main door D 2 , which can be opened only from outside the toilet  10 . 
         [0035]    The wall  14  is equipped with a sliding door  18 , which enables entrance/exit of the users (not shown), whilst a door  19  hinged on hinges  20  is provided on the wall  12 . The door  19  can be opened only in the case of emergency by specialized personnel (staff of the company responsible for maintenance of the toilet, firemen, etc.). 
         [0036]    Alongside the sliding door  18 , there is a device (not shown), referred to as “coin box”, for payment of the service. 
         [0037]    The self-cleaning toilet  10  moreover comprises a washing system  100 , which uses a rotary washing/drying arm  200  designed to rotate about a vertical axis (A) ( FIGS. 1 ,  7  and  8 ) through a maximum angle of 90°. The vertical axis (A) is fixed, with known means, to a service cabinet  210  made preferably of stainless steel, contiguous to the electrical and pneumatic technical space EPTS. 
         [0038]    As illustrated in greater detail in  FIG. 8 , the rotary washing/drying arm  200  comprises a substantially U-shaped press-bent plate  200   a  made of steel. In addition, the rotary washing/drying arm  200  comprises a first rectilinear portion  201 , the length of which is substantially equivalent to that of a first side portion HG 1  of a seat HG of the toilet bowl  16 . The first portion  201  of the rotary arm  200  continues with a second portion  202  inclined with respect to said first portion  201  by an angle such as to reproduce approximately the curvature of a second head portion HG 2  of the seat HG. 
         [0039]    Once again with reference to  FIG. 8 , it may be noted that the press-bent plate  200   a  houses inside it a box-shaped washing manifold  203 , provided with a plurality of washing nozzles  204 , set in use facing the seat HG of the toilet bowl  16 . Some devices (not shown), contained in the hydraulic technical space HTS and in the service cabinet  210 , send, via a pipe  207 , a washing solution of water and disinfectant to the washing manifold  203  and then to the nozzles  204 , by which it is sprayed onto the toilet bowl  16 , for example during a number N 1  of to-and-fro cycles, which can be set via an electronic control unit CC ( FIG. 1 ), of the rotary washing/drying arm  200 . 
         [0040]    In addition to the washing manifold  203 , located within the rotary washing/drying arm  200  is also a drying manifold  205  ( FIG. 8 ), which also has a boxlike shape, provided with a plurality of nozzles  206 , through which preferably hot air is sent. The drying operation is carried out according to the same criterion as that of “washing” with a number of to-and-fro cycles, programmable once again via the electronic control unit CC. 
         [0041]    The air is supplied to the drying manifold  205  via a pipe  207  ( FIG. 8 ). 
         [0042]    In the resting position, i.e., during the presence of the user within the internal space RM, the rotary arm  200  remains hidden away within the service cabinet  210 , it coming out only to carry out the cycles of cleaning set by the maintenance operator by means of an electronic control unit CC ( FIG. 1 ). 
         [0043]    In effect, as illustrated in  FIGS. 7 and 8 , the rotary arm  200  in the resting position is housed in a seat ST provided in the cabinet  210 . In other words, in the resting position ( FIG. 6 ) an external surface ES of the press-bent plate  200   a  is coplanar with an external surface  210   a  of a wall WL of the cabinet  210  facing the space RM. In this way, it is not necessary to use doors that open for exit of the washing member, but it is the external surface ES itself that functions as door when the rotary arm  200  is housed entirely in the seat ST. 
         [0044]    For actuation of the rotary washing/drying arm  200 , a pneumatic cylinder PC is used, which is able to convert a linear motion into a rotary motion (rotary actuator indicated by the double-headed arrow F). The pneumatic cylinder PC is housed in the service cabinet  210  in a position readily accessible from the electrical and pneumatic technical space EPTS. 
         [0045]    In addition, the pneumatic cylinder PC is connected to a pneumatic system IP comprising two electro-pneumatic valves V 1 , V 2 , associated to each of which is a respective pressure switch P 1 , P 2  for carrying out functions that will be described hereinafter. 
         [0046]    Preferably, to wash the seat HG and the side and internal walls of the toilet bowl  16  water containing disinfectant is sprayed by the nozzles  204 , said water containing disinfectant coming from a centrifugal pump (not illustrated) that raises the pressure of the liquid to 7 bar. 
         [0047]    In a further embodiment of the present invention, an instantaneous generator is used that produces steam, as an alternative to the pressurized washing solution, using an aqueous solution. One of the advantages of this latter solution as compared to the others lies in the fact that the use of steam at a high temperature eliminates the step of drying. The steam can be water vapour and can be distributed by a rotary arm of the type described. 
         [0048]    In addition, as illustrated in  FIG. 2 , the wall  12  is equipped, on the internal surface of the space RM, with a mirror  208  made of stainless steel, and an emergency push-button  209  (in addition to the already mentioned door  19 ). 
         [0049]    Located on the wall  15  (illustrated in  FIG. 3 ), in addition to the wash-basin  17  and to a device  17   a  designed to deliver a solution of hot water and neutral soap, hot water, and hot air for drying hands, is a hatch  211  for refuse, a further emergency push-button  212 , a loudspeaker  213 , a perfume nebulizer  214 , a microphone  215 , a push-button  216  for calls of a technical nature, a push-button  217  for calls of a sanitary nature, a light  218  for warning that the time available to the user is drawing to an end, and a push-button  219  for opening the door  18  by the user. 
         [0050]    The device  17   a  can moreover also perform the function of washing of the underlying wash-basin  17 , once the toilet  10  has been used and the user has left it. 
         [0051]    As regards the wall  14  ( FIG. 4 ), in addition to the already mentioned door  18 , also present are a dispenser  220  of paper seat-covers to be installed before use on the seat HG of the toilet bowl  16 , a handle  221  of possible aid for the user, and a push-button  222  for activation of a flush (not shown). 
         [0052]      FIG. 5  illustrates the devices that equip the wall  13 . In addition to the already described service cabinet  210 , toilet bowl  16 , and rotary washing/drying arm  200 , there is a handle  223 , a device for dispensing toilet paper  224 , and a further emergency push-button  225  located on the outer casing of the service cabinet  210 . The cycle of operation of the self-cleaning toilet  10  is managed in a completely automatic way by the electronic control unit CC. 
         [0053]    Furthermore, the bi-directional movement of the pneumatic cylinder PC (arrow F) that enables rotation through 90° of the rotary washing/drying arm  200  is guaranteed by two electro-pneumatic valves V 1 , V 2 , governed according to a program managed by the electronic control unit CC. For detection of the positions of the pneumatic cylinder PC, magnetic limit switches (not illustrated) are used. 
         [0054]    A very important aspect of the present invention relates to the safety equipment installed in the self-cleaning toilet  10 . 
         [0055]    In effect, the floor FL in the hydraulic technical space HTS and the electrical and pneumatic technical space EPTS is provided with a plurality of load cells  226  (four in the case in point), which are able to sense the presence of a user within the toilet  10 . The load cells  226  also have the purpose of weighing the user. The floor FL in turn comprises a metal load-bearing structure coated with a metal plate of large thickness covered by a ribbed mat made of non-slip rubber and in which the longitudinal axes of the ribbings extend from the wall  15 , in which the hydraulic technical space HTS is located, to the wall  13 , where the electrical and pneumatic technical space EPTS is installed. 
         [0056]    In effect, when the space RM has been left free by the user after use, in order to clean the floor FL, the system governed by the control unit CC sends water under pressure into a manifold CL located underneath the wash-basin  17 . The manifold CL is equipped with nozzles (not shown), from which there exit jets of water at a high pressure, which impinge upon the floor FL at a grazing angle. The jets draw along with them any possible refuse left on the floor FL by the user towards an evacuation gate SR ( FIG. 5 ), set underneath the toilet bowl  16 . 
         [0057]    Once the cycle of washing of the floor FL is completed, the jets of water are stopped, the gate SR is closed automatically ready for being re-opened at the next cycle. 
         [0058]    In addition, installed on the wall WL of the service cabinet  210  is a photoelectric-sensor detection system  227  ( FIGS. 5   6 ,  7 ,  8 ) that amply covers the range of sweep of the rotary washing/drying arm  200 . At a possible detection of a person or whatever else in the range of action of the rotary arm  200 , the system  227  immediately stops the course of the rotary arm  200 , or rather, blocks the cycle in progress, freeing the arm  200  from the forces of actuation, sending the pneumatic system IP into “discharge”, and putting the toilet  10  in an “out of order” condition. 
         [0059]    In other words, if the arm  200  finds any resistance along its path, this fact results in a corresponding raising of the pneumatic pressure in one of the pressure switches P 1 , P 2 , according to the direction of rotation of the arm  200  itself. 
         [0060]    The pneumatic system IP is conceived in such a way that, if the pressure in one of the two pressure switches P 1 , P 2  exceeds a given pre-set threshold, the pneumatic system IP itself goes into “discharge” and thus it is as if the arm  200  were “idle” about the axis (A). 
         [0061]    At the same time, an “out of order” signal is generated. 
         [0062]    Operation of the self-cleaning toilet  10  is represented schematically in the flowchart of  FIGS. 9 and 10 . 
         [0063]    The routine starts with a block (S), where the payment is made by the user via the coin box of the amount established for use of the toilet  10 . In block (S) also the door  18  opens and the user enters the space RM. 
         [0064]    Weighing of the user is performed by means of the load cells  226 . If the weight detected is less than 20 kg or more than 250 kg, the system enables use of the toilet bowl  16  and of the other toilet facilities only with the door  18  open in order to prevent a small child from remaining closed in the toilet  10  by mistake or else a number of persons from being closed inside at a time. 
         [0065]    If the check on the weight has yielded a positive result, the door  18  closes after a check (CHECK  1 ) appearing in block (X) has been made. The door  18  first makes three attempts at closing, and if it does not find any obstacles it closes; if, instead, it encounters an obstacle, it again makes attempts at closing; if the attempts at closing continue to be unsuccessful, it is evident that the toilet  10  is out of order, and this fact is signalled on the panel of the coin box. 
         [0066]    In the case where the toilet  10  presents any faults, the system goes to a block (Y), in which there is intervention of the technical-assistance and maintenance service and a manual “reset” of the public toilet  10  itself on the part of specialized personnel. 
         [0067]    Illustrated in block (T) are the various steps followed by the system during a check for presence or otherwise of fumes, in particular inside the hydraulic technical space HTS and the electrical and pneumatic technical space EPTS. Evidently, if the system detects the presence of fumes, control returns to block (Y). 
         [0068]    Represented in block (U) is the activation of the various push-buttons  209 ,  212 ,  216 ,  217 ,  219  and  225 . 
         [0069]    If the user remains in the toilet  10  for less than 15 minutes and presses the push-button  219 , the door  18  opens with an acoustic and visual warning. Immediately after, the door  18  re-closes, and the system passes to point ( 2 ) of block (W). 
         [0070]    Consequently, the washing cycle starts, performed by the rotary arm  200  on the toilet bowl  16 , by the device  17   a  on the wash-basin  17 , and by the jets of pressurized water that exit from the floor-washing manifold CL. After flushing the floor FL and removing any possible refuse present thereon, the water is discharged through the gate SR located on the opposite side. 
         [0071]    It should be noted, moreover, that in block (W) there is also made a check by the photoelectric-sensor detection system  227  as well as the check by the pressure switches P 1 , P 2 . 
         [0072]    A check (CHECK  2 ), identical to CHECK  1 , which is also represented in block (X), regards the checks that are made by the system for detecting any possible faults occurring during closing of the gate SR. 
         [0073]    To return to block (V), in addition to the already mentioned check on the time of permanence of the user in the toilet  10 , there is a check on the presence of electric mains current at the moment when the user wishes to open the door  18  by pressing the push-button  219 . 
         [0074]    The safety procedure is provided only on the emergency push-buttons  212 ,  209  and  225 ; in effect, the user resorts to an emergency push-button only if the “exit” push-button  219  does not activate opening of the door  18 . If the system verifies that there is no electric mains current, it switches immediately onto a standby battery. In the case where also the standby battery were to be out of order, a tank for accumulation of air under pressure (not shown) is actuated, which in any case enables opening of the door  18 . 
         [0075]    The user presses the push-button  219  just once, and the system resorts to the solution suited to the need in a completely automatic way. 
         [0076]    The main advantages of the self-cleaning toilet forming the subject of the present invention are described in what follows:
       a rotary washing/drying arm, the external surface of which, in the resting position, is coplanar with the external surface of a cabinet; in this way, it is not necessary to use doors that open for exit of the washing member; and   a safety system that is extremely effective because it envisages the use of as many as three devices (load cells on the floor, photoelectric sensors on the service cabinet, and pressure sensors in the pneumatic control system of the rotary arm) for detecting the unwanted presence of a user inside the toilet during the steps of cleaning thereof.

Summary:
A self-cleaning public toilet comprising a safety and alarm system. The safety and alarm system includes a plurality of load cells that weigh the user who has entered a space; a photoelectric-sensor device, for detecting the presence or otherwise of a person in the space during washing and drying of the inside of the toilet; and at least one pressure switch located in a pneumatic system for supply of a pneumatic cylinder that actuates a rotating arm for cleaning a toilet bowl.