Abstract:
A fluid expansion valve with a main body and a method of its use. The main body has an internal fluid passage and an outlet connector. The outlet connector is suitable for delivering the expanded fluid and for connecting with a socket. The internal profile of the socket is suited for connection with the external profile of the outlet connect. The outlet connect has three connention sections of varying external diameters. The valve may be used to introduce a pressurized gas to a liquid or a beverage.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to an expansion valve the gas outlet coupling of which comprises an external profile suited to taking a user connector with a complementary internal profile, preferably a expansion valve with a non-adjustable reduced pressure for gas cylinders, particularly those which may be used in the field of food, particularly for drinks, in the field of welding, in laboratories or the like. 
   2. Related Art 
   Existing gas valve assemblies with built-in pressure reducers, also known as expansion valves, like the one described in document EP-A-0747796, usually have at least one device for interrupting the delivery of high-pressure gas, a pressure reducer, a system for adjusting the pressure and the flowrate, and a coupling for the gas outlet and to which the user can connect. 
   The device for interrupting the delivery of high-pressure gas is composed mainly either of the valve shutter of the pressure reducer when the expansion valve assembly has just one shutter, or of a shutter separate from the pressure-reducing shutter, when the expansion valve assembly has several valve shutters, generally two shutters. 
   When the operator wishes to obtain gas, he has therefore to perform two or even three successive operations, namely to connect a gas outlet coupling to the body of the expansion valve assembly, to open the gas passage by operating a valve or a control lever on the gas outlet, and possibly to adjust the flowrate and/or the pressure of the gas to the desired value. 
   Now, in a certain number of uses or applications, these successive operations on the part of the user on the expansion valve assembly may give rise to:
         a risk of error leading to malfunctioning, particularly on the part of users who have little or no technical awareness, which is, in particular, the case in the application to the tapping off of CO 2 , because the users of CO 2  in packaged form are, in particular, proprietors or managers concerned with delivering drinks, such as beer or other sparkling beverages which are served on tap in this type of establishment, particularly fizzy drinks, and   a significant length of time spent using the gas, which may sometimes prove to take quite a long time until the desired result is obtained.       

   In an attempt at solving this problem, an expansion valve which is simpler to use than the conventional expansion valves, even for users with no particular technical awareness as it has a reduced number of operations that need to be performed when the user taps off gas, has already been proposed and this valve being characterized by the presence of a gas outlet coupling which can take a user connector and which delivers reduced-pressure gas at a reduced pressure that the user cannot adjust, that is to say at a predetermined fixed pressure of, for example, 8 bar. 
   Now, at the present time, gas outlet couplings of this type of expansion valve are all practically identical or differ from one another only very slightly, which means that there may be a significant risk of error, when the user connection is being connected or coupled to the said coupling by an ill-informed operator. 
   SUMMARY OF THE INVENTION 
   The purpose of the present invention is therefore to solve the above problem by proposing an improved expansion valve. 
   The solution to this problem therefore consists in a fluid expansion valve preferably with a preset reduced pressure comprising:
         a main body within which there is formed at least one internal passage for fluid between at least one inlet port for fluid whose pressure is to be reduced, and at least one outlet port for reduced-pressure fluid,   fluid pressure-reducing means arranged in or on at least part of the said internal fluid passage, between the said inlet port and the said outlet port, and designed to reduce the pressure of the fluid, and   an outlet coupling able to deliver the said reduced-pressure fluid, the internal fluid passage opening to the outlet end of the said reduced-pressure fluid outlet coupling and the said outlet coupling comprising an external profile designed to take and have connected to it a user connector which has an internal profile tailored to and/or complementing the said external profile of the said coupling, characterized in that the outlet coupling comprises at least three cylindrical coupling portions arranged in succession from the outlet end of the said outlet coupling towards the end via which the said outlet coupling is coupled to the body of the expansion valve, the first coupling portion P 1  having a first outside diameter D 1 , the second coupling portion P 2  having a second outside diameter D 2  and the third coupling portion P 3  having a third outside diameter D 3 , which diameters are such that D 1 &lt;D 2 &lt;D 3  and D 1  is between 6 mm and 10 mm, D 2  is between 7 mm and 18 mm and D 3  is between 11 mm and 19 mm.       

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the nature and objects for the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein: 
       FIG. 1  illustrates a view in longitudinal section of an expansion valve in accordance with one illustrative embodiment of the present invention. 
       FIG. 2  illustrates a view in longitudinal side view of an outlet coupling for an expansion valve in accordance with one illustrative embodiment of the present invention. 
       FIG. 3  illustrates a view of the user outlet connector and the outlet coupling in accordance with one illustrative embodiment of the present invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   As appropriate, the expansion valve of the invention may have one or more of the following features:
         the outlet coupling furthermore comprises a fourth cylindrical coupling portion P 4  having a fourth outside diameter D 4 , situated between the third portion P 3  of outside diameter D 3  and the end via which the outlet coupling is coupled to the body of the expansion valve, with D 3 &lt;D 4  and D 4  between 12 mm and 21 mm; the end via which the outlet coupling is coupled to the body of the expansion valve being the end of the coupling via which the said coupling is fixed or secured to the body of the expansion valve,   the outlet coupling further comprises a fifth cylindrical portion P 5  of fifth outside diameter D 5  situated between the fourth portion P 4  of outside diameter D 4  and the end via which the said outlet coupling is coupled to the body of the expansion valve, with D 5 &gt;D 4  and D 5  between 15 mm and 27 mm,   the outlet coupling further comprises a sixth cylindrical portion P 6  of outside diameter D 6  situated between the third portion P 3  of outside diameter D 3  and the fourth portion P 4  of outside diameter D 4 , with D 3 &gt;D 6  and D 6  between 7 mm and 18 mm, preferably between 8 mm and 17 mm,   D 1  is between 7 mm and 9 mm, D 2  is between 8 mm and 17 mm, D 3  is between 12 mm and 18 mm, D 4  is between 13 mm and 20 mm, D 5  is between 16 mm&lt;D 5 &lt;26 mm and/or D 6  is between 8 and 12 mm,   the first coupling portion P 1  has an external length L 1  of between 6 mm and 9 mm, preferably between 7 mm and 8.5 mm,   the second coupling portion P 2  has an external length L 2  of between 1.5 mm and 4 mm, preferably between 2 mm and 3.5 mm,   the third coupling portion P 3  has an external length L3 of between 0.5 and 3 mm, preferably of the order of 1.2 mm,   the fourth coupling portion P 4  has an external length L 4  of between 2 mm and 6 mm and/or preferably of the order of 3.5 mm,   the fifth coupling portion P 5  has an external length L 5  of between 2 mm and 6 mm, preferably of the order of 3.5 mm,   the sixth coupling portion P 6  has an external length L 6  of between 2.5 mm and 5 mm, preferably 3 and 4.5 mm,   the second coupling portion P 2  and the third coupling portion P 3  are separated by a ramp and/or the first coupling portion P 1  has a chamfer at the outlet end of the outlet coupling,   the outlet coupling comprises at least one coupling valve shutter able to move in translation in the outlet coupling when a user outlet connector comprising means of actuating the valve shutter which collaborate with the said valve shutter so as to move the shutter is connected to the said coupling,   the fluid pressure-reducing means comprise a pressure-reducing valve shutter positioned in a fixed pressure-reducing position that cannot be altered by the user and that corresponds to the said preset pressure value,   the fluid pressure-reducing means allow the fluid to have its pressure reduced to a preset pressure value of between 4 bar and 12 bar, more preferably still of between 5 bar and 10 bar,   the coupling valve shutter moves in translation in the outlet coupling when a user outlet connector comprising means of actuating the coupling valve shutter which collaborate with the said valve shutter so as to obtain the said movement is connected to the said coupling,   the outlet coupling has a profile tailored to collaborate with a guiding and locking system formed in a user outlet connector with a complementary profile,   the outlet coupling comprises a valve shutter spring means collaborating with the coupling shutter and at least one seal and a bearing surface making it possible to obtain sealing against fluid of the fluid outlet port borne by the coupling.       

   According to another aspect, the invention relates also to a system for transferring fluid comprising a gas expansion valve according to the invention, and a gas outlet connector having an internal profile which complements the external profile of the said outlet coupling and comprising a body in which there is formed an internal guidance and locking system used to receive and guide the end of the outlet coupling of the expansion valve and, also, to prevent the connector from becoming disconnected from the said coupling by collaborating with the external profile of the external peripheral wall of the coupling, the said connector also comprising a connector valve shutter which normally rests against a valve seat and can be moved in translation along the longitudinal axis of the connector. 
   The invention also relates to a container of pressurized fluid, particularly a gas cylinder, equipped with a expansion valve according to the invention, preferably the said assembly is inserted in and protected by a protective bonnet mounted on the container. 
   The present invention will now be better understood by virtue of the detailed description which follows, given with reference to the appended figures. 
     FIG. 1  depicts a view in longitudinal section of a expansion valve  50  according to the invention the body  30  of which contains a part which acts as a pressure reducer. The level of pressure reduction is either preset to a given pressure that the user cannot alter, for example 8 bar, or is adjustable by the user according to the level of pressure required in the application in question. 
   Setting the pressure to its desired fixed value is performed in a way known per se and will not be detailed hereinbelow. 
   According to the invention, the body  30  also comprises a gas-outlet coupling  1  with shut-off allowing easy and quick connection and disconnection of an outlet connector to this expansion valve  50  so that the gas reduced to the said reduced pressure downstream of the pressure reducer can be collected and then used. 
   The opening for the gas passing through the body  30  of the expansion valve assembly  50  is controlled downstream of the pressure-reducing part and is synchronized with the connection of the gas outlet connector (see  FIG. 3 ) by the user to the gas outlet coupling  1 . 
   Connecting this gas tapping or outlet connector to the gas outlet coupling  1  makes it possible, apart from the actual connection proper, to achieve sealing followed by a release of gas at the desired pressure. 
   Furthermore, a gas cylinder equipped with this type of expansion valve  50  can be filled without removing the assembly and this can be done simply by supplying the filling valve  31  with gas under pressure (high pressure) which then passes through the body  30  via the internal passage  32 ,  32   c ,  32   a  connecting the said filling valve  31  to the connection fitting  35  that allows the expansion valve  50  to be fixed to the neck of a gas cylinder. The internal gas passage  32 ,  32   c  passes axially through the connecting fitting  35  which carries an external screw thread  36 . 
   In fact, the passage  32  here comprises three portions  32   a ,  32   b  and  32   c . The portions  32   c  and  32   a  of the internal passage  32  connect, as explained hereinabove, the filling valve  31  to the connection fitting  35  and therefore to the inside of the cylinder, and are used when filling with high-pressure gas, while the passages  32   a  and  32   b  connect the inside of the cylinder, via the fitting  35 , to the outlet port  18  borne by the outlet coupling  1  of the invention so as to allow the user to be supplied with low-pressure gas, that is to say gas at a pressure which has been reduced by comparison with the pressure of the gas in the container bearing the expansion valve  50 . 
   By virtue of this type of expansion valve, use of the gas at low pressure is reduced to a single operation which is simple and quick. 
   If the user connector, supplying the user&#39;s gas circuit, is also of the type with shut-off, the use of a expansion valve according to the invention also preserves the quality of the gas. 
     FIG. 2  depicts a longitudinal side view of an outlet coupling  1  for a expansion valve  50  according to the invention, to which can be connected and fixed a user connector  20  which can adopt various forms of embodiment, such as a connector  20  with a fixing ring or collar or, as the case may be, with a control button as illustrated in FIG.  3 . 
   The gas expansion valve further comprises, as detailed in  FIGS. 1 and 2 , a main body  30  within which there is formed the internal gas passage  32  between an inlet port  37  for the gas that is to be reduced in pressure, for example the gas at a high pressure of 100 bar, carried by the fitting  35 , and an outlet port  18  for gas reduced to the desired pressure, for example a fixed pressure of 8 bar. Pressure reduction is performed by conventional fluid pressure reducing means  32   d  arranged in the path of the gas, in or on part of the said internal gas passage  32  between the inlet port  37  and the outlet port  18 . Gas is distributed to the user via the gas outlet coupling  1  according to the invention which is able to deliver the reduced-pressure gas, that is to say the gas after pressure reduction by the said pressure-reducing means which in particular comprise a expansion valve shutter, a pressure-reducing port and a valve seat all collaborating with one another in a known way to reduce the pressure of the high-pressure gas. 
   The internal gas passage  32  opens (at  32   b ) at the outlet end  11  of this reduced-pressure fluid outlet coupling  1  and also comprises an external profile suited to receiving and to having connected to it a user connector  20  which has an internal profile tailored to and/or complementing the said external profile of the said coupling. 
   To solve the problem of the invention, the outlet coupling  1  comprises several cylindrical coupling portions P 1  to P 6 , arranged so they are successive from the outlet end  11  of the outlet coupling  1  towards the end  10  via which the latter is coupled to the body of the expansion valve. The respective coupling portions P 1  to P 6  each have a respective outside diameter D 1  to D 6  as defined above. 
   By way of example, the dimensions (in mm) of the various diameters D 1  to D 6  of couplings  1  of several expansion valves according to the invention are given in Table I below. 
   
     
       
             
             
             
           
             
             
             
             
             
             
             
           
             
             
             
             
             
             
             
             
           
         
             
                 
               TABLE I 
             
           
           
             
                 
                 
             
             
                 
               Diameters 
                 
             
           
        
         
             
                 
               D1 
               D2 
               D3 
               D4 
               D5 
               D6 
             
             
                 
                 
             
           
        
         
             
                 
               Example 1 
               8 
               9 
               13 
               14 
               21 
               9.5 
             
             
                 
               Example 2 
               8 
               12 
               13 
               14 
               17 
               9.5 
             
             
                 
               Example 3 
               8 
               9 
               13 
               15 
               20 
               9.5 
             
             
                 
               Example 4 
               8 
               10 
               13 
               15 
               19 
               9.5 
             
             
                 
               Example 5 
               8 
               11 
               13 
               14 
               18 
               9.5 
             
             
                 
               Example 6 
               8 
               13 
               17 
               18 
               25 
               9.5 
             
             
                 
               Example 7 
               8 
               16 
               17 
               18 
               21 
               9.5 
             
             
                 
               Example 8 
               8 
               13 
               17 
               19 
               24 
               9.5 
             
             
                 
               Example 9 
               8 
               14 
               17 
               19 
               23 
               9.5 
             
             
                 
               Example 10 
               8 
               15 
               17 
               18 
               22 
               9.5 
             
             
                 
                 
             
           
        
       
     
   
   Furthermore, the lengths L 1  to L 6  of the various portions P 1  to P 6  in examples 1 to 10 above were as given in Table II below. 
   
     
       
             
           
             
             
             
             
             
             
             
           
         
             
               TABLE II 
             
             
                 
             
           
           
             
               Lengths of portions P1 to P6 (in mm) 
             
           
        
         
             
                 
               L1 
               L2 
               L3 
               L4 
               L5 
               L6 
             
             
                 
                 
             
             
                 
               7.75 
               2.75 
               1.2 
               3.5 
               3.5 
               3.8 
             
             
                 
                 
             
           
        
       
     
   
   In  FIG. 3  it can be seen that when the user connector  20  is connected (direction of the arrow F) to the coupling  1 , the internal part of the said connector  20  fits over the external profile of the outlet coupling  1 . 
   More specifically, the user connector  20  has a fixing end which comprises an internal housing the profile of which is tailored to and complements that of the coupling  1  and which is intended to receive the projecting end of the coupling  1 . 
   The fact of giving the coupling  1  several diameters D 1  to D 5  which differ and which increase, from the outlet end  11 , makes it possible not only to facilitate the connecting of the connector to the coupling but also to avoid any risk of significant error when an ill-informed operator is connecting or coupling the user connector to the said coupling, because a connector with a profile not specific to that of the coupling will not be able to be coupled to it. 
   Furthermore, in order to make connection even quicker and more effective the connector  20  also comprises an internal guiding and locking system used, on the one hand, to receive and to guide the end  11  of the coupling  1  and, on the other hand, to prevent the connector  20  from becoming disconnected from the coupling  1 , after coupling, by collaborating with the portions P 3  and P 6  of the coupling, which portions are situated peripherally on the cylindrical coupling  1  and respectively constitute a projecting annular part (P 3 ) and a recessed annular portion forming a groove (P 6 ). 
   Furthermore, the user connector  20  comprises a conventional system for controlling the passage of fluid from the coupling to the connector  20 , which system in particular comprises a connector valve shutter equipped with a projecting portion which normally rests against a valve seat so as to shut off the fluid passage of the connector by means of the projecting portion borne by the valve shutter. An elastic means, such as a spring, exerts a thrusting force on the rear part of the shutter tending to push it back towards its seat. Conversely, when the valve shutter is lifted off its seat, fluid can flow into the connector  20  from its inlet end, through the fluid passage from which the projecting portion of the valve is now extracted, and is discharged via the central passage of the connector  20 . An appropriate seal provides sealing between the coupling  1  and the connector  20  when these are connected to one another. 
   Furthermore the coupling  1  for its part comprises a coupling shutter and a shutter spring, and a seal, which seals the fluid outlet port, at a bearing surface. 
   The positioning of the connector  20  on the coupling  1  and the errorproofing associated with the specific profile of the assembly are achieved by pushing the user connector  20  in a translational movement over the outlet coupling  1  of the expansion valve. Sealing is obtained gradually by continuing to insert the connector  20  over the cylindrical outlet end of the coupling  1 . When sealing has been achieved, the shutters in the connector and in the coupling respectively gradually open, these collaborating with one another by pushing each other back in synchronism or, as the case may be, successively one after the other. Furthermore, the locking system plays its part so as to allow the connector  20  to be fixed securely to the coupling  1 . After that, as the shutters are lifted off their respective seats, the cycle of reducing the pressure to the desired pressure can begin and the reduced-pressure gas then passes to the user connector  20  and is then conveyed, via appropriate means, particularly pipes, hoses or the like, to the gas user site. Conversely, disconnection can be achieved by performing the opposite. 
   The expansion valve of the invention is particularly well suited to delivering a gas under pressure intended to pressurize a drink, particularly beer or a fizzy drink. 
   It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above.