Patent Publication Number: US-7581263-B2

Title: Toilet flush water opening device provided with an electrohydraulic actuator

Description:
The invention relates to a toilet flush opening device of the type that comprises a water cistern supplied by a valve connected to a water supply system, and that can be opened to allow the cistern to be filled if the water level drops below a predetermined lower limit, and of the type that comprises a lower discharge aperture and a vertical moveable discharging open/close element for this aperture, which is able to occupy a closed lower position to keep the water in the cistern or an open upper position to discharge the water into a toilet bowl. 
   BACKGROUND OF THE INVENTION 
   Numerous examples of flush opening devices of this kind are known. 
   Most of them are devices in which the discharging open/close element is operable mechanically by way of a member moved directly by the user. 
   This configuration, when installed in public toilets frequented by large numbers of users, leads to many user problems. Specifically, users may forget to operate the actuating member of the discharging open/close element and the state of cleanliness of the toilets can decline rapidly. 
   To overcome this problem, toilet flush opening devices have been disclosed in which the discharging open/close element can be moved automatically by an electrical device. 
   This configuration consumes a lot of energy because in order to move the discharging open/close element it must have a high-power electrical supply such as a mains supply. 
   To solve this problem, toilet flush opening devices have been disclosed in which the discharging open/close element can be operated by a submerged float that can be released into a position of actuating the open/close element by an electrical device. 
   This configuration is satisfactory but the problem with it is that while the flush is not being used the electrical device is under permanent stress from the submerged float. 
   SUMMARY OF THE INVENTION 
   To solve this problem, the invention provides a toilet flush opening device of the type described above, in which the open/close element can be moved by an electrohydraulic actuator. 
   To this end, the invention provides a toilet flush opening device of the type described above, characterized in that the open/close element can be moved from its lower position to its upper position by an electrohydraulic actuator which comprises a controlled solenoid valve able to occupy an inactive position or an active position, in which active position it delivers water at pressure, and an expandable hydraulic device supplied by the solenoid valve and connected mechanically to the open/close element, which is moveable between:
         a retracted position in which it is not supplied by the solenoid valve and does not move the open/close element, and   an extended position in which it is supplied with water at pressure by the solenoid valve and tends to move the open/close element from its closed lower position to its open upper position.       

   In accordance with other features of the invention:
         the toilet flush opening device comprises, fixed inside the cistern, an essentially tubular and vertical casing whose lower end comprises an open/close element seat coinciding with the lower discharge aperture of the cistern and inside which there is mounted a sliding actuating rod whose lower end comprises an open/close element seat seal and whose upper end, which projects from the casing, can be actuated by the expandable hydraulic device to actuate the open/close element seat,   the expandable hydraulic device is mounted on an upper face of the tubular casing and it comprises at least one moveable upper actuating face that is able, when the expandable hydraulic device is in the extended position, to apply force to a shoulder element mounted on the upper end of the actuating rod,   the expandable hydraulic device comprises:
           a vertical guide pin mounted on the upper face of the tubular casing,   a tubular cylindrical body mounted so as to slide on the pin,   a cap, which closes the upper end of the cylindrical body and whose upper face is the moveable upper actuating face, and   housed in the tubular cylindrical body between the cap and the upper end of the pin, an inflatable element that can be supplied with water at pressure from the solenoid valve via a channel which extends through the cap so as to inflate and push against the upper end of the pin in such a way as to lift the cap and apply force to the shoulder element of the actuating rod,   
           the inflatable element consists of a membrane attached to the underside of the cap and defining an inflatable chamber that can be supplied by the channel passing through the cap with water at pressure from the solenoid valve and that is able, in the absence of water at pressure, to drain into the cistern via at least one hole in the cap by the forces of gravity acting on the actuating rod, on the tubular cylindrical body and on the cap of the expandable hydraulic device,   the cap has on its upper face a connecting adapter inside which the channel is formed and which is connected to the solenoid value via a flexible tube,   the shoulder element of the actuating rod is a split washer which fits into a groove formed at the end of the actuating rod,   the casing houses a submerged assistance float that is attached to the actuating rod and that has buoyancy features such that:
           in the retracted position of the electrohydraulic actuator linked with the closed lower position of the open/close element, the buoyancy of the assistance float does not overcome the resultant of the forces of gravity acting on the actuating rod and the open/close element,   in the extended position of the electrohydraulic actuator associated with the open upper position of the open/close element, the buoyancy of the assistance float is added to the actuating force of the electrohydraulic actuator to assist the rise of the actuating rod carrying the seal of the open/close element.   
               

   The invention also relates to a method of controlling a solenoid valve of an electrohydraulic actuator for a toilet flush opening device. 
   In a first embodiment of this method, it comprises at least one step linked to the complete draining of the cistern during which the solenoid valve is activated for a first period linked to the complete draining of the cistern. 
   In a second embodiment of this method, it also comprises at least one step linked to a partial draining of the cistern during which the solenoid valve is activated for a second predetermined period corresponding to a part of the first period linked to the complete draining of the cistern. 
   In a third embodiment of this method, it comprises a step linked to the complete draining of the cistern during which the solenoid valve is activated for a reduced period so that the expandable hydraulic device provides a pulse to the actuating rod such as to drain the cistern completely, and the submerged float assists the rise of the actuating rod and that of the seal of the open/close element. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages will become apparent in the course of reading the following detailed description, for an understanding of which the reader should refer to the attached drawings, in which: 
       FIG. 1  is a general perspective view of a toilet flush opening device according to the invention; 
       FIG. 2  is a general view in axial section through the toilet flush opening device of  FIG. 1 , shown with the expandable hydraulic device retracted; 
       FIG. 3  is a general view in axial section through the toilet flush opening device of  FIG. 1 , shown with the expandable hydraulic device extended; 
       FIG. 4  is a general view in axial section through a toilet flush opening device in a variant shown in the extended position of the expandable hydraulic device. 
   

   DETAILED DESCRIPTION OF THE PREFFERED EMBODIMENTS 
   In the following description, identical references denote identical parts or parts having similar functions. 
   The figures show the whole of a toilet flush opening device  10  constructed in accordance with the invention. 
   As in the prior art, the device  10  comprises a water cistern  12  that is supplied by a valve (not shown) connected to a water supply system, and that can be opened to allow the cistern  12  to be filled if the water level drops below a predetermined lower limit. The cistern  12  comprises a lower discharge aperture  14  and a vertical moveable discharging open/close element  16  for this aperture  14 , which is able to occupy a closed lower position, shown in  FIG. 2 , to keep the water in the cistern  12  or an open upper position, shown in  FIGS. 3 and 4 , to discharge the water into a toilet bowl (not shown). 
   Conventionally, the discharging open/close element  16  can be actuated mechanically by way of a component moved directly by the user. 
   Effective as this construction may be when installed in a private dwelling or in infrequently used toilets, it is not suitable for public toilets used by large numbers of people. 
   To solve this problem, there exists in the prior art a toilet flush opening device  10  in which the open/close element  16  can be moved in an automated manner by an electric actuator. 
   This configuration consumes a lot of energy because in order to move the discharging open/close element  16  it needs a high-power electrical supply such as a mains supply. 
   The invention provides a toilet flush opening device  10  in which the open/close element  16  can be moved in an automated manner by an electric actuator running off a low-power electricity supply, meaning that said device can be used in toilets installed in places that do not have a high-power electricity supply. 
   The invention is thus of particular application to public toilets remote from a mains electricity supply—as for example, without limiting the invention, beach toilets or portable toilets erected temporarily at public gatherings. 
   To this end, as shown in  FIG. 1 , the invention provides a toilet flush opening device  10  of the type described earlier, characterized in that the open/close element  16  can be moved from its lower position to its upper position by an electrohydraulic actuator  18 . 
   As shown in  FIG. 1 , this electrohydraulic actuator  18  comprises a controlled solenoid valve  20  able to occupy an inactive position (not shown) or an active position (not shown), in which active position it delivers water at pressure, and an expandable hydraulic device  22  which is supplied by the solenoid valve  18  and is connected mechanically to the open/close element  16 . 
   More particularly, as illustrated in  FIGS. 2 and 3 , this expandable hydraulic device  22  is moveable between:
         a retracted position, shown in  FIG. 2 , in which it is not supplied by the solenoid valve  20  described above with reference to  FIG. 1 , and does not move the open/close element  16 , and   an extended position, shown in  FIG. 3 , in which the expandable hydraulic device  22  is supplied with water at pressure by the solenoid valve  20  described above with reference to  FIG. 1 , and tends to move the open/close element  16  from its closed lower position to its open upper position.       

   More particularly, as shown in  FIGS. 1-4 , the flush opening device  10  according to the invention comprises, fixed inside the cistern  12 , an essentially tubular and vertical casing  24 . 
   For this purpose, a threaded tubular lower end  26  of the casing  24  extends through the discharge aperture  14  of the cistern  12  and is fixed relative to the cistern  12  by an opposing nut  30  to immobilize the casing  24  inside the cistern  12 . 
   The lower end  26  of the casing  24  comprises an open/close element seat  28  that coincides with the lower discharge aperture  14  of the cistern  12 . 
   Mounted inside the casing  24 , in an upper bearing  36 , is a sliding actuating rod  32  whose lower end comprises a seal  34  for the open/close element  16  seat  28  and whose upper end  38  projects from the casing  24 . This upper end  38  can be actuated by the expandable hydraulic device  22  to actuate the seal  34  of the open/close element  16 . 
   Any form of mechanical connection between the expandable hydraulic device  22  and the actuating rod  32  may be suitable for successful implementation of the invention. 
   However, in the preferred embodiment of the invention, the expandable hydraulic device  22  is mounted on an upper face  40  of the tubular casing  24  and comprises at least one moveable upper actuating face  42  that is able, when the expandable hydraulic device shown in  FIG. 3  is in the extended position, to apply force to a shoulder element  44  mounted on the upper end  38  of the actuating rod  32 . 
   This shoulder element may for example be a split washer  44  that fits into a groove  45  formed at the end  38  of the actuating rod  32 . 
   The expandable hydraulic device  22  may be implemented in any way, provided it is capable of lifting the shoulder element  44  of the actuating rod  32  through a sufficient stroke to open the open/close element  16 . 
   As shown in the figures, the expandable hydraulic device  22  preferably comprises:
         a vertical guide pin  46  which is mounted on the upper face  40  of the tubular casing  24  and has a hemispherical upper end  47 ,   a tubular cylindrical body  48  mounted so as to slide on the pin  46 ,   a cap  50 , which closes the upper end of the cylindrical body  48  and whose upper face is the moveable upper actuating face  42 , and   housed in the tubular cylindrical body  48  between the cap  50  and the upper end  47  of the pin  46 , an inflatable element  52  that can be supplied with water at pressure from the solenoid valve  20  via a channel  54  which extends through the cap  50  so as to inflate and push against the upper end  47  of the pin  46  in such a way as to lift the cap  50  and apply force to the washer  44  of the actuating rod  32 .       

   The inflatable element preferably consists of a membrane  52  that is attached to the underside of the cap  50 , or that is clamped between the cap  50  and the body  48 , and that defines an inflatable chamber  56  that can be supplied via the channel  54  passing through the cap  50  with water at pressure from the solenoid valve  20 . 
   In the absence of water at pressure, this chamber  56  is able to drain spontaneously into the cistern  12  through at least one hole  58  in the cap, by the forces of gravity acting on the actuating rod  32 , on the tubular cylindrical body  48  and on the cap  50  of the expandable hydraulic device. The hole  58  is so designed that the flow rate of the leak which it permits does not prevent the chamber  56  from being inflated when pressure is established in it. 
   To supply the chamber  56 , the cap  50  advantageously has on its upper face  42  a connecting adapter  60  inside which the channel  54  is formed and which is connected to the solenoid value  20  via a flexible tube  62 , as shown in  FIG. 1 . 
   In the preferred embodiment of the invention, which is shown in  FIGS. 1-3 , the casing  24  houses a submerged assistance float  64  that is attached to the actuating rod  32  and that has buoyancy features such that:
         in the retracted position of the electrohydraulic actuator  18  associated with the closed lower position of the open/close element  16 , as shown in  FIG. 2 , the buoyancy of the assistance float  64  does not overcome the resultant of the forces of gravity acting on the actuating rod  32  and the open/close element  16 ,   in the extended position of the electrohydraulic actuator  18  associated with the open upper position of the open/close element  16 , as shown in  FIG. 3 , the buoyancy of the assistance float  64  is added to the actuating force of the electrohydraulic actuator  18  and more particularly of the expandable hydraulic device  22 , to assist the rise of the actuating rod  32  carrying the seal  34  of the open/close element  16 .       

   In this configuration, which corresponds to a first embodiment of the invention, the solenoid valve  20  of the electrohydraulic actuator can be controlled by a method comprising a step linked to the complete draining of the cistern  12  during which the solenoid valve  20  is activated for a reduced period so that the expandable hydraulic device  22  provides a pulse to the actuating rod  32  such as to drain the cistern  12  completely, the submerged float  64  assists the rise of the actuating rod  32  and that of the seal  34  of the open/close element  16  and the open/close element  16  is only closed again when the water level in the cistern  12  has dropped sufficiently for the float  64  no longer to oppose the closing of the open/close element  16 . 
   In a second embodiment, as a variant of the invention more particularly shown in  FIG. 4 , the actuating rod  32  need not have an assistance float  64 , and in this case the actuating rod  32  is lifted purely by the force applied by the expandable device  22  on the washer  44 . 
   In this configuration the solenoid valve  20  of the electrohydraulic actuator may be controlled by an method comprising a step linked to the complete draining of the cistern  12 , during which the solenoid valve  20  is activated for a first predetermined period linked to the complete draining of the cistern  12 . This period can be determined very easily from the volume of water contained in the cistern and from the diameter of the aperture  14 . 
   Advantageously, in this second embodiment of the invention, the solenoid valve  20  of the electrohydraulic actuator may be controlled by a method that also comprises at least one step linked to a partial draining of the cistern  12  during which the solenoid valve  20  is activated for a second predetermined period corresponding to a part of the first period linked to the complete draining of the cistern  12 . 
   This second period may for example be a fraction of the first duration and can be used to drain a fraction of the volume of the cistern, depending on the type of matter to be flushed from the toilet. 
   The invention thus provides a compact and innovative toilet flush opening device that can be powered by a low-power electricity supply such as that delivered by a low-voltage cell or battery.