Abstract:
The present invention relates to a quick connection which comprises two elements, male and female, adapted to fit axially in each other. The body of the female element is equipped with a loaded bolt, mounted to slide in this body and pierced with a central opening for fit of the male element, the wall of this opening being equipped with three teeth offset with respect to one another along a median axis of the opening. The male element is provided with a shoulder adapted to rest selectively against one of the teeth. Means allow the downstream pipe to be placed in communication with the ambient atmosphere when the male element rests by its shoulder against the intermediate tooth.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a quick connection for the removable join of two pipes through which a pressurized fluid passes.  
         BACKGROUND OF THE INVENTION  
         [0002]    Patent FR 2 514 855 discloses a quick connection which comprises two elements, male and female, adapted to fit axially, provoking the opening of a valve mounted in the body of the female element, this body being equipped with a loaded bolt, mounted to slide in this body and pierced with a central opening for the fit of the male element. The wall of the opening of the bolt presents three teeth offset with respect to one another along a median axis of this opening, while the male element is provided with a shoulder adapted to rest selectively against one of these teeth. The movement of unlocking of this known connection takes place in two steps corresponding respectively to the abutment of the shoulder of the male element on the intermediate tooth and on the tooth nearest to the opening of the female element. When the male element rests by its shoulder against the tooth nearest the opening, the air contained in the conduit connected to the male element may be driven to the outside without too great a risk of tear of the male element or of a whipping movement of the pipe associated therewith.  
           [0003]    This conventional arrangement is satisfactory from the standpoint of robustness and of reliability.  
           [0004]    However, when the male element is in abutment by its shoulder against the intermediate tooth, it exerts thereon an effort which depends on the pressure of the fluid present in the pipe connected to the male element. -This effort induces frictions which oppose the slide of the bolt in the body of the female element. In order to overcome these efforts of friction, it is necessary to use a powerful spring which elastically loads the lock towards a position of disengagement of the intermediate tooth. This may prove a hindrance during the coupling of the connection as the effort generated by this spring must be overcome in order to allow the introduction of the male element in the female element.  
           [0005]    In other words, a connection of the afore-mentioned type becomes difficult to manoeuvre when it is used with a fluid at relatively high pressure. Now, such a connection must be able to be used for fluid networks at 6 or 10 bars, and even 25 bars, in which case it is effectively delicate to manoeuvre manually.  
           [0006]    In practice, the geometry of the male connector element, which is standardized, should not be modified.  
           [0007]    It is an object of the present invention to propose a quick connection which may be easily manoeuvred, including when the pressure of the fluid is relatively high, and which comprises a standard male connector.  
         SUMMARY OF THE INVENTION  
         [0008]    To that end, the invention relates to a connection of the afore-mentioned type which comprises means for placing the downstream pipe in communication with the ambient atmosphere when the male element rests by its shoulder against the intermediate tooth.  
           [0009]    Thanks to the invention, the downstream pipe may be drained of the fluid that it contains, while the male connector is in abutment on the intermediate tooth, with the result that, when this draining operation is terminated, the pressure prevailing in the downstream pipe is substantially equal to the ambient pressure and the shoulder does not exert a considerable effort on the intermediate tooth, this allowing the bolt to be easily manoeuvred.  
           [0010]    According to advantageous but non-obligatory aspects of the invention, this connection incorporates one or more of the following characteristics:  
           [0011]    The afore-mentioned communicating means comprise at least one orifice formed in the body of the female element, downstream of the valve. This orifice may advantageously be obturated by the male element when the latter rests by its shoulder against the tooth most remote from the opening of a central conduit of the female element. In other words, this orifice is closed when the connection is in passing configuration. In addition, this orifice may be provided to extend in a direction which is substantially radial with respect to the axis of fit of the male and female elements.  
           [0012]    The communicating means are arranged in a zone of the body of the female element distinct from the part in which the bolt slides. Thanks to this aspect of the invention, the fluid coming from the downstream pipe does not risk disturbing slide of the bolt.  
           [0013]    The communicating means are arranged upstream of that part of the body of the female element in which the bolt slides.  
           [0014]    The female element is equipped with means adapted to ensure seal of the connection between the male and female elements, while, when it rests against the intermediate tooth, the male connector is disengaged with respect to the sealing means. In this way, the sealing means do not oppose the drain of the downstream pipe. 
       
    
    
       [0015]    The invention will be more readily undestood on reading the following description of an embodiment of a quick connection in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings, in which:  
         [0016]    [0016]FIG. 1 is an axial section of a quick connection according to the present invention, the male and female elements being shown in passing and locked position.  
         [0017]    [0017]FIG. 2 is a section similar to FIG. 1 during a first step of opening of the connection.  
         [0018]    [0018]FIG. 3 is a section similar to FIG. 1 during a second step of opening of the connection, and  
         [0019]    [0019]FIG. 4 is a section similar to FIG. 1 when the male and female elements are uncoupled. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
       [0020]    Referring now to the drawings, the connection shown in FIGS.  1  to  4  comprises a female element A and a male element or connector B connected respectively to an upstream pipe C 1  and to a downstream pipe C 2 . The upstream pipe C 1  is itself connected to a source of fluid under pressure (not shown).  
         [0021]    The body  1  of the female element presents a substantially cylindrical and circular outer shape, centred on an axis X-X′ which is also the longitudinal axis of a conduit  11 , inside the body  1  and in which is disposed a valve  2  mobile along axis X-X′. The body  1  is also equipped with a seal  3  forming seat for the valve and disposed inside a groove  12  made in the wall of the conduit  11 .  
         [0022]    The body  1  forms a second groove  13  for receiving an O-ring  4 .  
         [0023]    The body  1  is also provided with a cylindrical housing  14  extending substantially in the direction of an axis Y-Y′ perpendicular to axis X-X′.  
         [0024]    Inside the housing  14  there is slidably mounted a bolt  5  on which a spring  6  exerts an elastic effort F 1  directed opposite the bottom  14   a  of the housing  14 , i.e. in the direction of its opening  14   b . The movement of the bolt  5  under the effort F 1  is limited by a projection  51  coming into abutment against a shoulder  14   c  of the housing  14 .  
         [0025]    The spring  6  is truncated in shape and engages in a reinforcement  56  provided on the outer surface of the bolt  5 .  
         [0026]    The bolt  5  is provided with a central opening  52  centred on an axis X 5 -X′ 5  parallel to axis X-X′. The opening  52  is bordered by three teeth.  
         [0027]    A first tooth  53  forms a surface  53   a  substantially perpendicular to axis X 5 -X′ 5 .  
         [0028]    A second tooth  54  is made on the side of the bolt  5  opposite spring  6 . It defines a surface  54   a  substantially perpendicular to axis X 5 -X′ 5 .  
         [0029]    A third tooth  55  is arranged on the side of the bolt  5  nearest the spring  6  and forms a surface  55   a  substantially perpendicular to axis X 5 -X′ 5 .  
         [0030]    The teeth  53 ,  54  and  55  extend from the circumference of the opening  52  in the direction of axis X 5 -X′ 5 . The tooth  53  is the most remote from the opening  15  of the conduit  11 , while tooth  55  is the closest to this opening, tooth  54  being intermediary between teeth  53  and  55 .  
         [0031]    A bore  16  connects the conduit  11 , downstream of the valve  2 , with the outer atmosphere E. In practice, and as is visible in FIGS. 3 and 4, a plurality of bores of the type such as bore  16  may be distributed about axis X-X′, one of these other bores appearing with reference  16 ′. In the example shown, the body  1  is provided with three bores  16 ′ distributed at 120° about axis X-X′.  
         [0032]    The male connector B comprises a metallic body  7  provided with a flange  71  forming a shoulder  72  intended to come selectively into abutment against one of the teeth  53 ,  54  or  55 .  
         [0033]    The flange  71  is also provided with an inclined ramp  73  which is truncated and convergent in the direction of the front end  74  of the body  7 .  
         [0034]    Functioning is as follows:  
         [0035]    When element B is fitted in element A, the functioning is similar to that of the known connection of FR 2 514 855.  
         [0036]    This makes it possible to attain the position of FIG. 1 where the flow of the fluid is represented by arrows F 2 . In this position, the connector B is in contact with the  0 -ring  4 , which avoids leakages towards the outside of the connection.  
         [0037]    In the configuration of FIG. 1, the body  7  obturates the bores  16  and  16 ′.  
         [0038]    From this position, and when it is desired to uncouple elements A and B, it suffices to exert on the bolt  5  an effort F 3  opposite effort F 1 , which has the effect of causing the bolt  5  to slide in the housing  14  in the direction of the bottom  14   a , this making it possible to disengage the teeth  53  with respect to the flange  71 . Due to this displacement, the tooth  54  is placed on the path of disengagement of the shoulder  72  which then comes into abutment against the surface  54   a . In this position shown in FIG. 2, the front end  74  of the body  7  is disengaged with respect to the valve  2  and to the  0 -ring  4 , while the bore  16  is in communication with the inner volume  75  of the body  7 , this allowing a flow of the fluid from the downstream pipe C 2  towards the outside E, as represented by arrow F 4 . The fluid located in the upstream pipe C 1  remains upstream of the valve  2  which is in firm abutment against its seat  3  under the effect of the pressure P prevailing in the upstream part of the conduit  11 .  
         [0039]    Thanks to the flow F 4 , the pressure P′ in the volume  75  decreases rapidly, with the result that the effort of friction between the shoulder  72  and the surface  54   a  decreases rapidly. When this effort of pressure attains a lower threshold value, this effort is overcome by the effort F 1  and the spring  6  pushes the bolt  5  towards the position of FIG. 3 where the connector  7  is efficiently retained in position thanks to the cooperation of the surface  55   a  and of the shoulder  72 .  
         [0040]    As the effort of friction between the surfaces  72  and  54   a  is relatively low, the effort F 1  which must be exerted by the spring  6  in order to return the bolt  5  towards the position of FIG. 3 is not too great, even if the original pressure P is relatively high. In effect, this effort F 1  is independent of this pressure, as it occurs after the drain of the pipe through bores  16  and  16 ′.  
         [0041]    The stiffness constant of the spring  6  may thus be chosen with a relatively low value. In this way, the user does not perceive too great a resistance to the effort F 3  which he must exert.  
         [0042]    The male element B may then be definitively released by a fresh pressing on the bolt  5 , as represented by arrow F′ 3  in FIG. 4, this pressing having the effect of retracting the tooth  55  with respect to the flange  71 . The connector B may in that case be withdrawn as represented by arrow F 5 .  
         [0043]    The invention makes it possible to effect draining of the downstream pipe on the intermediate tooth and, in this way, to limit the effort to be overcome in order to pass from the position of FIG. 2 to that of FIG. 3, i.e. to limit the stiffness constant of the spring  6 . This stiffness constant being less than in the known devices, the effort F 3  or F′ 3  to be exerted in order to drive the bolt  5  in the housing  14 , may be lower.  
         [0044]    The fact that the bores  16  and  16 ′ are located in a zone  17  of the body  1  distinct from the housing  14  avoids the essential of the flow F 4  propagating towards the interior of the housing  14  and tending to push the bolt  5  against the effort F 3 , which might cause the user instinctively to increase the pressure that he exerts with his finger on the outer surface  56  of the bolt or button  5 , and cause a complete unlocking of the connection before total drain of the downstream pipe C 2 .  
         [0045]    The invention therefore ensures that the pipe C 2  is efficiently drained before the male element B is withdrawn from the female element A.