Abstract:
The regulator comprises an enveloping body with a closure diaphragm on which a spring acts, said body comprising an entrance for the pressure liquid and an exit toward the pressure liquid application apparatus, characterised in that, at the bottom, the body comprises a closure plug with a graduable axial position for achieving a depressurisation position or free passage position, and, at the top, the compression spring on the diaphragm abuts against a flange of an asymmetrical intermediate body, of which the inversion brings about the two different preloading positions of the spring providing two regulator adjustment pressures.

Description:
DESCRIPTION  
       [0001]     The present invention is intended to disclose pressure regulator for liquids, in particular for achieving stable spraying in hand-operated agricultural and garden sprayers and the like, for treating large areas.  
         [0002]     As is known, the spray characteristics such as flow, angle, distribution, appearance of the liquid stream, droplet size, etc., which can be obtained with a hand sprayer, depend on the type of nozzle and the pressure of the liquid at the outlet thereof. However, application of a liquid by means of a hand sprayer involves a fluctuation in the outflow pressure as a function of the velocity of the piston thrust which brings about a variable flow and dispersion in the droplet size, reducing the efficiency of application and producing an increase in contamination for both the person carrying out the application and the environment.  
         [0003]     An object of the pressure regulator according to the present invention is to achieve an outflow of liquid at constant pressure, to allow the generation of droplets with much reduced dispersions in diameter and to optimise use of the volume of the chemical product applied.  
         [0004]     The pressure regulator according to the present invention substantially comprises a main body with openings for the admision and outflow of liquid, a pressure-regulating valve with a diaphragm-type closure which is subjected to the action of a spring, a combined intermediate throttle valve and a device for eliminating pressure or for depressurisation of the regulator. Furthermore, the regulator according to the present invention comprises very simple means for achieving two distinct outflow pressure values, one of which is much higher than the other, a fact which is achieved simply by changing the position of an asymmetrical abutment piece of the spring and then disassembling an external closure cap.  
     
    
       [0005]     For the purpose of better understanding there follow, by way of non-limiting example, some drawings of a liquid pressure regulator according to the present invention.  
         [0006]      FIG. 1  shows a complete section of the regulator.  
         [0007]      FIG. 2  shows a section of the regulator partially disassembled.  
         [0008]      FIG. 3  and  4  show respective details in section of the depressuriser.  
         [0009]      FIG. 5  shows a perspective view of the regulator.  
         [0010]      FIG. 6  shows a perspective view of the regulator with the control and exit assembled. 
     
    
       [0011]      FIG. 1  shows the pressure regulator in which a main body  1  comprises the liquid entrance  2  and, at the opposite end, the exit  3 , combined with the action of an internal throttle valve  14  connected to an intermediate closure plate  4  which is subjected to the action of the spring  5  and which acts on an internal closure flange  6  of the body by means of the diaphragm  7 .  
         [0012]     A lower cylindrical body or depressurisation plug  8  which is accommodated in the interior of the cylindrical recess  9  of the body  1  carries out closure or depressurisation as will be explained below.  
         [0013]     The illustrated regulator is arranged with its entrance  2  connected to a pressure liquid supply by a manual piston pump and its exit  3  to the spraying nozzle.  
         [0014]     When the pressure liquid enters the chamber  10  of the regulator, it passes through the orifice  11  of the body  1 , acting by means of the diaphragm on the valve plate  4  such that when the pressure of the spring  5  is overcome, said valve is raised, throttling the valve passage  14  which is conical and connected to the plate  4  with respect to the orifice  11 . Raising of the plate  4  allows passage of the liquid toward the exit  3  connected to the nozzle, so spraying commences.  
         [0015]     The throttle valve  14  is connected by ultrasound welding of its pin  13  to the plate  4  which is subjected to the action of the spring  5  and acts on the diaphragm  7  which is trapped between the pin  13  of the throttle valve  14  and the neck of the plate  4  in which said pin is ultrasonically welded. Therefore, displacement of the diaphragm corresponds to displacement of the plate  4  as well as to displacement of the throttle valve with pin  13  and conical head  14 . The throttling produced by the action between the cone  14  and the opening  11  generates a loss in load, for which reason the spring  5  can again overcome the force of the liquid, arriving at the other position of equilibrium. The pressure of the sprayed liquid is kept constant by this equilibrium.  
         [0016]     Different liquid outflow pressures can be obtained by changing the pressure of the spring  5 . According to the present invention, the regulator is calibrated to two outflow pressures, one lower one and one higher one, for example  1 . 5  and  3  bar, by means of the change in the position of an upper asymmetrical abutment piece  15  receiving the end of the spring  5 . Said upper abutment piece  15  comprises an external tubular element  16  equipped with the flange or thickened part  17  for receiving the spring  5  and which, at the top, comprises an extension  18  terminating in a centring prong  19  which fits into the upper opening  20  of the exterior cover  21  which is coupled so as to be capable of quick assembly and disassembly, for example by means of a bayonet coupling, relative to the body  1 . The distance between the faces of the flange  17  and the respective ends of the body are different such that, by disassembling the cover  21  and inverting the piece  15 , two spring pre-stressing positions can be achieved, one of which is shown in  FIG. 1  and the other corresponding to the inversion of said piece  15  with which centring is established in the opening  20  by means of the lower prong  22  which makes the piece  15  asymmetrical, i.e. the above-mentioned difference in length, this signifying greater compression of the spring  15 . Two pressure adjustment values of the regulator can thus be easily achieved.  
         [0017]     The pressure regulator according to the present invention also comprises means for eliminating pressure in the chamber  10 , allowing free outflow of the liquid, for which reason the lower displaceable body  8  abuts a lower cover  23  screwed into a tubular extension  24  of the body  1  and comprises two closure O-rings  25  and  26 , which act on the orifice  9  and on a smaller diameter orifice of said body respectively, thus closure the chamber  10 , as illustrated in  FIG. 3 . By partially unscrewing the lower cover  23 , the O-ring  26  stops closing the passage toward the chamber  10 , thus producing depressurisation by means of the passage  27 , as is illustrated in  FIG. 4 . This application is of particular interest for eliminating the pressure of the regulator and part of the circuit for the entrance of the liquid, at the end of the use thereof, avoiding the danger of contamination to the user.  
         [0018]     It will be understood therefore that the indicated construction of the pressure regulator according to the present invention means that three different regulation positions may be achieved very simply and easily, two of which are for two different liquid outflow pressures and the third for depressurisation or free passage since, as has been indicated, in the depressurisation position the chamber  10  communicates with the exit  3  by means of a passage  27 . The function of eliminating pressure is particularly beneficial when it is necessary to achieve some type of manipulation of the attachments in the portion of the circumference upstream of the regulator, because when the ingress pressure is less than that measured, closure produced by the spring brings about pressurisation of all of said section, for which reason said manipulation, for example for cleaning, etc., involves an increased risk of contamination since the treatment product can emerge under pressure toward the user or the environment.  
         [0019]     The position of free outflow or elimination of the pressure can be conveniently indicated in the cover  23  by means of inscriptions, which are not shown, in the zones  28  and  29  to indicate the regulator pressure and depressurisation positions. Said indications may also be arranged in the body  1  itself of the regulator by means of small arrows  30  and  31  or the like intended to coincide with a fixed indicator  32  in the lower cover  23 .  
         [0020]     To allow continuous visibility of the pressure indicator when it is being used, the upper part of the buttons  19  and  22  are to carry the corresponding indication and are to be visible at any instant by being able to turn the regulator with respect to the nozzle without the possibility of losing liquid owing to the arrangement of a special connecting nut  35 ,  FIG. 1 , which is capable of turning by means of an internal rib  33  that is introduced under pressure into a corresponding groove of the tubular ingress element  2  of the body  1 ; An internal toric coupling  34  guarantees a seal at any time, allowing said turning.  
         [0021]      FIG. 6  shows an arrangement of the regulator between the liquid ingress  36  carrying the manual control  37  and the outflow  38  toward the spray nozzle.  
         [0022]     To seal the external edge of the diaphragm  7 , the pressure regulator according to the present invention has an upper body  39  enclosing the spring  5  and which, at the bottom, widens to create a circular flange  40  which presses on the diaphragm  7  producing sealing thereof and also having a step  41  abutting a projecting zone  42  of the body, allowing ultrasonic welding thereof. The upper body  39  enclosing the spring  5  is thus connected and the diaphragm  7  is held in a sealed manner, closing the chamber  10  at the top.  
         [0023]     As will be understood, by means of said arrangement of elements it is possible to achieve a liquid pressure regulator which involves a simple variation in the supply pressure, a pressure elimination function of the remaining circumference of the entrance and a free passage position as well as efficient sealing of the diaphragm.