Abstract:
The present invention relates to a circuit for dispensing windshield washer fluid for a motor vehicle. According to the invention, the dispensing circuit is characterized in that it includes a float ( 11 ) housed inside a chamber ( 12 ) of a stationary body ( 13 ) so as to occupy a top position enabling the flow of the windshield washer fluid toward the nozzles, and a bottom position in which the chamber ( 12 ) is inoperative, an in which the float blocks the flow of the windshield washer fluid to the tank ( 2 ). The invention can be used in the automotive field.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is the US national stage under 35 U.S.C. §371 of International Application No. PCT/FR2011/052750 having an international filing date of Nov. 24, 2011, which claims the priority of French application 1059856 filed on Nov. 29, 2010. 
     BACKGROUND 
     The present invention relates to a circuit for dispensing windshield washer fluid for a vehicle, such as a motor vehicle. 
     Conventionally, a circuit for dispensing windshield washer fluid includes a storage tank for windshield washer fluid which is placed in the engine compartment of the vehicle, or in a free space of the fender of the vehicle, a pump optionally built directly in the storage tank, and a tube connecting the storage tank and the pump to the nozzles for spraying the windshield washer fluid onto the windshield of the vehicle or the glass lens of the vehicle&#39;s headlights, or to a nozzle for atomizing windshield washer fluid on the back window of the vehicle. 
     The nozzles are sometimes mounted on the support arms of the wiper blades or on the wiper blades themselves, and a portion of the tube is then located outside the vehicle. 
     Under these conditions, due to the fact that the nozzles and the outer portion of the feed tube supplying windshield washer fluid to the nozzles are not protected by the engine of the vehicle, the windshield washer fluid present in the nozzles can freeze in cold weather and due to the aerodynamic effect of the forward movement of the vehicle, making the nozzles unusable. 
     A simple solution to prevent the freezing of the windshield washer fluid in the nozzles and in the outer tube portion consists in completely purging the circuit for dispensing windshield washer fluid by returning it into the tank. 
     However, the disadvantage of this solution is that it increases the response time of the window washing function, especially when the tank and the pump are installed far from the nozzles. 
     The document DE 3840621 describes a circuit for dispensing windshield washer fluid comprising a valve making it possible to direct the windshield washer fluid to at least one nozzle when a feed pump supplying windshield washer fluid is activated, and allowing the windshield wiper fluid standing in a portion of the tube located outside, between the nozzle and the valve, to be discharged into the storage tank for windshield wiper fluid when the pump is stopped in order to prevent the fluid from freezing in cold weather. The valve consists of a movable part that occupies a different position depending on the pressure of the windshield wiper fluid, thus opening specific passages in order to make it possible to supply the nozzle with windshield washer fluid or to discharge the windshield washer fluid contained in the outer tube portion connected to the nozzle. 
     However, the design of such a valve is fairly complex and costly. 
     SUMMARY 
     The purpose of the present invention is to overcome the above disadvantages of the known circuits for dispensing windshield washer fluid. 
     For this purpose, a circuit for dispensing windshield washer fluid for a vehicle, such as a motor vehicle, includes at least one nozzle, a valve assembly arranged in a tube connecting the nozzle to a tank for windshield washer fluid and a washing fluid feed pump. The circuit makes it possible to direct the windshield washer fluid to the nozzle when the pump is activated, and to return the windshield washer fluid present in a first tube section between the nozzle and the valve assembly to the tank when the pump is stopped. To enable this functionality, the valve assembly includes a float housed in a chamber of a stationary body communicating, on the one hand, with the first tube section connecting the valve assembly to the nozzle, and, on the other hand, with a second tube section connecting the valve assembly to the tank and to the pump. The float can occupy a top position in the chamber when the pump is activated to enable the passage of the windshield washer fluid from the second tube section to the first tube section through the chamber, and can drop with the level of windshield washer fluid in the chamber when the pump is stopped to enable the discharge of the windshield washer fluid in the first section to the second tube section through the chamber until the float occupies a bottom rest position in the chamber in which it obstructs or closes the passage of the windshield washer fluid to the second section and blocks a column of windshield washer fluid in this second section. 
     According to a first embodiment, the float comprises a needle-shaped float having an upper rod which enables guided sliding of the needle-shaped float relative to the stationary body between the float&#39;s top and bottom rest positions. A lower end of the float bears, in the bottom rest position of the needle-shaped float, against a sealing seat located at the bottom of the stationary body and communicating with the second tube section. 
     Advantageously, an annular sealing gasket is inserted between the lower end of the needle-shaped float and the sealing seat. 
     The annular sealing gasket is rigidly connected to the sealing seat or to the lower end of the needle-shaped float. 
     The lower end of the needle-shaped float and the sealing seat are frusto-conical. 
     According to a second embodiment, the float comprises a ball that bears with sealing contact, in its bottom rest position, against an annular sealing gasket rigidly connected to the bottom of the stationary body having an opening communicating with the second tube section. 
     According to a variation of this embodiment, the ball has an upper rod enabling the guided sliding of the ball relative to the stationary body between its top and bottom rest positions. 
     Advantageously, the float can be maintained in its bottom rest position by magnetization means. 
     According to an embodiment, the magnetization means includes a magnet housed in the float, and a metal part or another magnet rigidly connected to the stationary body near the magnet of the float in order to magnetically attract the magnet of the float toward the metal part of the other magnet. 
     According to another embodiment, the magnetization means includes a metal coating rigidly connected to the float, and a magnet rigidly connected to the stationary body near the metal coating in order to magnetically attract the float. 
     The float is made of a plastic material. 
     The float, in addition, has a density lower than that of the windshield washer fluid. 
     The nozzle is mounted on a windshield wiper of the vehicle, and at least a portion of the first tube section is located outside the engine hood of the vehicle. 
     The invention also relates to a vehicle, such as a motor vehicle, which is characterized in that it is provided with a circuit for dispensing windshield washer fluid as defined above. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       The invention will be better understood, and other purposes, characteristics, details and advantages thereof will become clearer in the following description made in reference to the appended drawings, which are given solely as examples illustrating several embodiments, and in which: 
         FIG. 1  is a is a schematic representation of a circuit for dispensing windshield washer fluid; 
         FIG. 2  is a diagrammatic representation in cross section of a valve assembly with a float located in the dispensing circuit of  FIG. 1 , and occupying a rest position; 
         FIG. 3  is a view similar to that of  FIG. 2 , representing the float in a top position for the passage of windshield washer fluid for supplying at least one washing nozzle; 
         FIGS. 4 and 5  are diagrammatic representations in cross section of an embodiment of the valve assembly with a float; 
         FIG. 6  represents a first embodiment of the float comprising a needle-shaped float occupying its bottom rest position with a sealing gasket located in the sealing seat of the needle-shaped float; 
         FIG. 7  is a view similar to that of  FIG. 6 , representing the needle-shaped float in its top position for the passage of windshield washer fluid for supplying the washing nozzles; 
         FIGS. 8 and 9  represent a variation of the embodiment of  FIGS. 6 and 7 , according to which magnetization means are provided in order to maintain the needle-shaped float in its bottom rest position; 
         FIGS. 10 and 11  represent a variation of the embodiment of  FIGS. 6 and 7 , according to which no sealing gasket is provided between the needle-shaped float and its sealing seat; 
         FIGS. 12 and 13  represent a variation of the embodiment of  FIGS. 10 and 11 , according to which magnetization means are provided in order to maintain the needle-shaped float in its bottom rest position; 
         FIGS. 14 and 15  represent another embodiment of the needle-shaped float member provided with a sealing gasket occupying a bottom rest position and a top position for the passage of windshield washer fluid to the washing nozzles, respectively; 
         FIGS. 16 and 17  represent a variation of the embodiment of  FIGS. 14 and 15 , according to which magnetization means are provided in order to maintain the needle-shaped float in its bottom rest position; 
         FIGS. 18 and 19  represent a second embodiment of the float comprising a guided ball occupying a bottom rest position bearing against a sealing gasket and a top position for the passage of windshield washer fluid to the nozzles, respectively; 
         FIGS. 20 and 21  represent a variation of the embodiment of  FIGS. 18 and 19 , according to which magnetization means are provided in order to maintain the guided ball in its bottom rest position; 
         FIGS. 22 and 23  represent another embodiment of the float comprising a free ball occupying a bottom rest position bearing against a sealing gasket and a top position for the passage of windshield washer fluid to the nozzles, respectively; and 
         FIGS. 24 and 25  represent a variation of the embodiment of  FIGS. 22 and 23 , according to which magnetization means are provided in order to maintain the ball in its bottom rest position. 
     
    
    
     DETAILED DESCRIPTION 
     Referring first to  FIG. 1 , reference numeral  1  denotes a circuit for dispensing windshield washer fluid of a vehicle, the circuit  1  including a storage tank  2  for storing windshield washer fluid, a feed pump  3  for supplying windshield washer fluid, which can be built directly in the tank  2 , a tube  4  connecting the pump  3  to two washing nozzles  5  for washing a window of the vehicle, in particular the front window of the vehicle. In this case, the two nozzles  5  can be mounted on the two pivoting support arms of the windshield wiper blades or on the wiper blades themselves, respectively. However, the two nozzles  5  can be mounted on two support arms of wiper blades for the glass lenses of the headlights of the vehicle, or on the wiper blades themselves, respectively. It is also possible to provide only a single nozzle mounted on a support arm of the wiper blade of the back window of the vehicle or on the wiper blade itself. A valve assembly  6  is located along the tube  4  and makes it possible to direct the windshield washer fluid to the nozzles  5  when the pump  3  is activated in order to clean the window and to lower or discharge the windshield washer fluid present or standing in a first upper section  7  of the tube  4 , which is located between the nozzles  5  and the valve assembly  6 , back into the tank  2  when the pump  3  is stopped. 
     According to the design of the dispensing circuit represented in  FIG. 1 , the tank  2  and the pump  3  are arranged in the bottom portion of the engine compartment  8  of the vehicle, which is closed by the hood  9 , or they can be arranged in a free compartment of the fender of the vehicle. 
     The valve assembly  6  and the second section  10  of the tube  4  connecting the valve assembly to the pump  3  and to the tank  2  are also arranged in the engine compartment of the vehicle or under the scuttle/cowl grille, with it being possible for the assembly to be arranged substantially on the tank  2 . 
     The first upper tube section  7  rigidly connected to the nozzles  5  is, for the most part, arranged outside the engine compartment  8  of the vehicle without being protected by the hood  9 . Hence, the windshield washer fluid contained in the nozzles  5  and in the first upper section  7  can freeze in cold weather or due to the aerodynamic effect of the forward movement of the vehicle. 
     As represented in  FIGS. 2 and 3 , the valve assembly  6  includes a float  11  housed in a chamber  12  of a body  13  forming a stationary casing in the engine compartment of the vehicle, or under the scuttle grille, the chamber or body extending vertically. 
     The chamber  12  communicates with the first tube section  7  through an opening  14  produced in the side wall of the body  13 , substantially in the middle of the same, the opening  14  being extended on the outside by a pipe  15  of short length to which the corresponding end of the first section  7  is rigidly connected. The chamber  12  also communicates with the second tube section  10  through an opening  16  which is formed in the lower wall of the body  13  and extended on the outside by a pipe  17  of short length to which the corresponding end of the second section  10  is rigidly connected. 
     When the pump  3  is actuated by a command of the user of the vehicle, the windshield washer fluid under pressure penetrates into the chamber  12  through the lower opening  16  and moves the float  11  to its top position in the chamber  12  of the body  13 , in which the windshield washer fluid is allowed to pass through the chamber  12  and the side opening  14 , as represented symbolically by the arrow F 1  in  FIGS. 3 and 5 , and to circulate subsequently in the first tube section  7 , in order to supply windshield washer fluid to the nozzles  5  which spray the windshield washer fluid onto the window to be cleaned. 
     When the control unit of the pump  3  is no longer activated, the windshield washer fluid present in the first tube section  7  and in the chamber  12  below the float  11  descends back to the storage tank  2  through the second tube section  10 , with a lowering of the float  11  as the level of fluid in the chamber  12  drops until the float  11  reaches a relatively low position as represented in  FIG. 2 , in which it rests as a result of gravity on a sealing seat, and is maintained on this seat by a “suction cup” effect due to the windshield washer fluid present in the portion of the chamber  12  below the float  11  and in the second tube section  10 , so that the float  11  obstructs the passage of the windshield washer fluid in the section  10 , and blocks the water column under the second tube section  10 . In this manner, all the windshield washer fluid that was present in the first tube section  7  is discharged into the tank  2  through the valve assembly  6 . Naturally, the float  11  must have a density lower than that of the windshield washer fluid, so as not to obstruct the return of the windshield washer fluid as soon as the pump  3  is stopped and enable the windshield washer fluid to return in part to the tank  2  after it has been discharged by gravity from the first tube section  7 . The float  11  can have a density less than one. 
     As shown in  FIGS. 2 and 3 , the sealing seat of the float  11  comprises an annular sealing gasket  18  rigidly connected to the inner cylindrical surface of the body  13 . 
     Preferably, the float  11  is made of a plastic material and can have the general shape of a piston which is axially guided in the body  13  and whose lower surface has a convexity turned toward the gasket  18 . 
     By emptying the first tube section  7  of the windshield washer fluid, there is no longer any risk of the windshield washer fluid freezing in cold weather or due to the aerodynamic effect of the forward movement of the vehicle. Additionally, the blocking of the windshield washer fluid in the water column under the float  11  in the position represented in  FIG. 2  makes it possible to preserve a relatively rapid response time for the window washing function as soon as the pump is activated again. 
     The embodiment represented diagrammatically in  FIGS. 4 and 5  differs from that of  FIGS. 2 and 3  only in general shape of the float, the float being in the form of a needle-shaped float whose conical lower end  19  bears with sealing contact against the complementarily-shaped seat  20  provided at the bottom of the body  13  when the float  11  occupies its bottom rest position for closing the passage of the windshield washer fluid to the tank  2 , as shown in  FIG. 4 . 
     The functioning of the float  11  is identical to that of  FIGS. 2 and 3 , except that, once the windshield washer fluid has been discharged from the first tube section  7  to the tank  2 , fluid remains at the bottom of the chamber  12  up to the seat  20 , and a column of fluid remains in the second tube section  10  and under the conical end  19  of the float  11  so as to apply a suction cup effect pressing the conical end  19  of the float  11  onto the seat  20 , as shown in  FIG. 5 . In general, residual fluid remains at the bottom of the chamber  12  when the float  11  occupies its top position for the passage of the windshield washer fluid to the nozzles  5 , as shown in  FIG. 5 . 
     Like the float  11  of  FIGS. 2 ,  3 , the float of  FIGS. 4 ,  5  can be made of a plastic material and it has a density less than that of the windshield washer fluid. 
       FIGS. 6-17  represent several embodiments of the needle-shaped float  11 . 
     According to these embodiments, the body  13  in which the float  11  is housed comprises two portions including a generally cylindrical base body  21  in which the chamber  12  is defined and a cover  22  covering the base body  21  in order to close the chamber  12 . 
     The cover  22  comprises two oblique upper pipes  15  located on both sides of the cover communicating with the chamber  12  respectively through two diametrically opposite openings  14  produced in the side wall  21   a  of the base body  21  and to which the ends of the two pipes forming the first tube section  7  are connected, respectively, each tube being connected to a nozzle  5 . 
     The base body  21  includes a vertical lower pipe  17  to which the corresponding end of the second tube section  10  is connected and which communicates with the chamber  12 . 
     An annular sealing gasket  21   b  is inserted between the side wall of the cover  22  and the side wall  21   a  of the base body  21 , housed in a groove of the side wall  21   a.    
     According to the embodiments of  FIGS. 6-13 , the needle-shaped float  11  includes an upper cylindrical rod  23  which is mounted so that it slides, guided between its upper position for supplying windshield washer fluid to the nozzles  5  and its bottom rest position for obstruction of the passage of this fluid to the tank  2 , in a stationary sleeve  24  rigidly connected to the upper wall of the cover  22  and protruding into the chamber  12 . 
     The frusto-conical lower end  19  of the needle-shaped float  11  bears, in the bottom rest position of the float, against a complementarily shaped sealing seat  20  communicating with the outer pipe  17  of the chamber  12 . 
     According to the embodiment represented in  FIGS. 6-9 , the frusto-conical end  19  of the needle-shaped float  11  also bears with sealing contact, in its bottom rest position, against an annular sealing gasket  18  housed in an annular groove  21   c  formed in the frusto-conical seat  20  of the base body  21 . 
     The functioning of the valve assembly  6  having a needle-shaped float  11  is the same as for the valve assembly described in reference to  FIGS. 4 and 5 , that is to say when the pump  3  is actuated by a command of the user, the windshield washer fluid under pressure raises the needle-shaped float  11  which is moved in a guided manner to the top until it abuts against the upper wall of the cover  22 , and the frusto-conical lower end  19  is released from its seat  20  and from the sealing gasket  18 , in order to allow the windshield washer fluid to circulate in the body  13  to the nozzles  5  through the pipes  15  and corresponding feed pipes (i.e., tubes  7 ) that supply the nozzles  5  with windshield washer fluid. When the command to activate the pump ceases, the windshield washer fluid present in the first tube section  7  descends back into the tank  2  through the body  13  in which the needle-shaped float  11  drops as the level of fluid in the chamber  12  drops, until the frusto-conical lower end  19  of the float  11  bears with sealing contact against its seat  20  and against the gasket  18  in such a manner as to obstruct the passage of the windshield washer fluid to the tank  2  and block the column of windshield washer fluid under the needle-shaped float  11  and in the second tube section  10 , which column exerts a suctioning effect on the frusto-conical end  19 , so as to maintain the conical end  19  bearing against the seat  20  and the gasket  18 . 
     The embodiment of  FIGS. 8 and 9 , in comparison to that of  FIGS. 6 and 7 , comprises magnetization means that allow application of the frusto-conical lower end  19  of the needle-shaped float  11  against the sealing gasket  18  and against the seat  20  in the rest position of the float, in order to prevent a complete emptying of the dispensing circuit in case of vehicle vibrations capable of being applied to the float  11 . 
     These magnetization means can include a magnet  25  housed in the frusto-conical lower end of the needle-shaped float  11  and a metal part  26  attached outside the base body  21  near the magnet  25  so that they attract each other mutually magnetically in a direction that makes it possible to apply the end frusto-conical  19  against the sealing gasket  18  and the seat  20 . 
     The metal part  26  can be in the shape of an annular ring which is rigidly connected to the base body  21  coaxially with respect to the outer pipe  17 . 
     As a variant, the magnetization means can comprise a magnet instead of the metal part  26 , and a metal part instead of the magnet  25  or another magnet instead of the metal part  26  in addition to the magnet  25  present in the frusto-conical lower end  19  of the needle-shaped float  11 . 
     According to another embodiment, the magnetization means can comprise a magnet instead of the metal part  26  and a metal layer coating the frusto-conical lower end  19  of the float  11 , outside or inside. 
     Naturally, the force of magnetic attraction exerted by the magnetization means in order to maintain the frusto-conical lower end  19  of the float  11  with sealing contact against the gasket  18  and the seat  20  has to be less than the pressure of the windshield washer fluid exerted on the float  11  when the pump  3  is activated, so as to ensure under normal conditions the circulation of the windshield washer fluid to the nozzles  5 , and this force of magnetic attraction must be negligible when the float  11  descends back to its seat  20  as soon as the pump  3  is stopped, in order to enable the windshield washer fluid present in the first tube section  7  to be discharged completely into the tank  2 . This force of attraction intervenes only once the float  11  is in its rest position. 
     The embodiment of  FIGS. 10-13  differ from the embodiment of  FIGS. 6-9  only in the absence of a sealing gasket  18 , so that the frusto-conical lower end  19  of the float  11  bears with sealing contact against its seat  20  only when the float  11  occupies its bottom rest position for obstruction of the passage of windshield washer fluid to the tank  2 . 
     The embodiment of  FIGS. 10 and 11  comprises no magnetization means making it possible to maintain the frusto-conical lower end of the float  11  on its sealing seat  20 , while the embodiment of  FIGS. 12 and 13  comprises such magnetization means whose embodiment variants have already been described in reference to  FIGS. 8 and 9  and will thus not be described in detail again. 
     The embodiment represented in  FIGS. 14-17  differs from that of  FIGS. 6-13  in that the lower end  19  of the needle-shaped float  11  has a generally cylindrical shape, comprising an outer groove  19   a  in which the annular sealing gasket  18  is housed, and which bears with sealing contact against an inner annular seat  20  of the base body  21  when the float  11  occupies its bottom rest position. The sealing seat defines a central opening capable of communicating with the outer pipe  17  through a frusto-conical orifice  21   d  of the base body  21 . 
     The embodiment of  FIGS. 16 and 17  differs from that of  FIGS. 14 and 15  in that it comprises magnetization means that make it possible to maintain the sealing gasket  18  of the lower cylindrical end of the float  11  in sealing contact against its seat  20  when the float occupies its bottom rest position. These magnetization means can have various embodiment variants as described in reference to  FIGS. 8 and 9  and they will therefore not be described in detail again. 
     I The embodiment of  FIGS. 14-17  functions in the same manner as the embodiment described in reference to  FIGS. 6-13 . 
     According to the embodiment represented in  FIGS. 18-21 , the float  11  includes at its lower end a generally spherical portion or a portion in the form of a ball  19  over which a cylindrical rod  23  hangs capable of sliding guided in the vertical direction in a stationary sleeve  24  of the cover  22 , as in the various embodiments described in reference to  FIGS. 6-17 . 
     As in the case in particular of  FIGS. 6 and 7 , an annular sealing gasket  18  is housed in a circular groove  21   c  produced in the frusto-conical opening  21   d  of the base body  21  in such a manner that the ball  19  of the float  11  bears with sealing contact against the gasket  18  when it occupies its bottom position for obstruction of the passage of the windshield washer fluid, represented in  FIG. 18 . 
     When the pump  3  is actuated by a command of the user, the pressure of the windshield washer fluid in the opening  21   d  raises the ball float  11  to a top position in order to disengage the ball from the sealing gasket  18  to allow the windshield washer fluid to flow out through the two pipes  15  of the cover  22  in order to supply the nozzles  5  with windshield washer fluid. When the command is no longer activated, the windshield washer fluid standing in the first tube section  7  descends again and returns to the tank  2 . The ball float  11  descends in the chamber  12  as the level of fluid present in the chamber drops until the ball  19  of the float  11  bears with sealing contact against the gasket  18  in order to prevent the remaining windshield washer fluid from returning to the tank, and from being maintained in the water column under the ball  19  of the float  11 , exerting on the ball  19   a  suctioning effect which maintains the ball in sealing contact on the gasket  18 . 
     The embodiment of  FIGS. 20 and 21  differs from that of  FIGS. 18 and 19  only in the presence of magnetization means making it possible to maintain the ball  19  of the float  11  in sealing contact on the gasket  18  when it occupies its bottom rest position. These magnetization means have various embodiments already described in reference to  FIGS. 8 and 9  and they will therefore not be described again, except to say that they make it possible for the ball  19  of the float  11  to be properly applied on the gasket  18  in its rest position, in order to prevent a complete emptying of the dispensing circuit in case of vehicle vibrations capable of being applied to the float  11 . 
     According to the embodiment represented in  FIGS. 22-25 , the float  11  comprises only a ball held freely in the chamber  12 , between its bottom position in sealing contact on an annular sealing gasket  18  installed in a circular groove  21   c  of the base body  21 , as in the embodiment variants of  FIGS. 18-21 , and a top position abutting with the free end of the stationary sleeve  24  of the upper wall of the cover  22 . 
     When the pump  3  is actuated by a control of the user, the pressure of the washing fluid penetrating into the chamber  12  raises the ball  11  to a top position until it abuts with the lower free end of the sleeve  24 , in order to allow the windshield washer fluid to flow out through the two outer pipes  15  in order to supply the nozzles  5  with windshield washer fluid. When the command is no longer activated, the windshield washer fluid present in the first tube section  7  descends back to the tank  2 , through the chamber  12  in which the ball  11  descends as the level of fluid in this chamber drops until the ball rests on the sealing gasket  18  so as to obstruct the passage of the windshield washer fluid, in order to prevent it from returning to the tank  2  and block the column of windshield washer fluid on the ball  11 , exerting on the latter a suctioning effect which maintains it bearing against the sealing gasket  18 . 
     The embodiment of  FIGS. 24 and 25  differs from that of  FIGS. 22 and 23  in that it comprises magnetization means making it possible to apply the ball  11  against the sealing gasket  18  in its rest position and to prevent the complete emptying of the dispensing circuit in case of vehicle vibrations capable of being applied to the ball. These magnetization means can have various embodiments already described particularly in reference to  FIGS. 8 and 9 . 
     Regardless of the various embodiments described in reference to  FIGS. 6-25 , the float  11  can be made of a plastic material while being hollow on its inside, and, naturally, the density of the float  11  is less than the density of the windshield washer fluid. 
     The above-described dispensing circuit of the invention is a simple, effective, and inexpensive design aiming to prevent the windshield washing fluid present in the outer tube section  7  from freezing in cold weather and due to the aerodynamic effect of the forward movement of the vehicle. In addition, the design of this dispensing circuit is such that it does not increase the response time of the window washing function carried out by the nozzles and it prevents the complete draining of the entire dispensing circuit.