Patent Abstract:
A female element of a quick connection provided with a closure valve, wherein the opening of the valve is controlled by a reaction force exerted by an O-ring disposed in an inner housing of a body of a male connection element adapted to be fitted in the female element. The reaction force results from the abutment of the valve on the O-ring when the male and female elements are coupled together. Upon the failure of the O-ring, the valve is not displaced so that the risks of leakages are eliminated.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to a female element of a quick connection. It also relates to a quick connection for removably joining pipes conveying fluid under pressure, as well as to an installation for filling automobile vehicle tanks with gas under pressure, incorporating such a female element. 
   BACKGROUND OF THE INVENTION 
   In the domain of filling automobile vehicle tanks with gas under pressure, particularly liquefied petroleum gas (LPG), it is known that each automobile vehicle may be equipped with a male connector constituting the end of a pipe connected to a tank, this connector being intended to cooperate with a female element belonging to a filling installation, such as a service station. This male connector and this female element together form a quick connection intended to be manipulated by a consumer, such as the driver of an automobile vehicle. 
   Normally, the male connector of the automobile vehicle is equipped with an O-ring which ensures insulation between the channel for circulation of gas under pressure, formed by the coupled connection elements, and the ambient atmosphere. Now, it may happen that the O-ring, which should be present on the connector of an automobile vehicle, is absent due to wear and tear, cut, or further to an accidental ejection. The filling of a vehicle whose male connector is bereft of an O-ring is potentially dangerous, particularly due to the explosive nature of certain gases. 
   Similar problems are raised in other domains where an O-ring is used on a male connection element. 
   It is a more particular object of the present invention to overcome these drawbacks by eliminating, as far as possible, the risk of transit of fluid through the male and female elements of connections in the absence of an O-ring with which the male element must normally be equipped. 
   SUMMARY OF THE INVENTION 
   In that spirit, this invention relates to a female element of a quick connection provided with a closure valve, characterized in that the opening of this valve is controlled by an effort of reaction exerted by an O-ring disposed in an inner housing in the body of a male connection element adapted to be fitted in the female element, this effort resulting from the abutment of the valve on the O-ring further to the coupling of these male and female elements. 
   Thanks to the invention, the female element is opened, by displacement of its valve, only further to the interaction of the latter with the O-ring of a male element. 
   According to advantageous but non-obligatory aspects of the invention, a female connection element may incorporate one or more of the following characteristics: 
   The valve is provided with a part adapted to be engaged in the inner volume of the body of a male connection element and to come into abutment against the O-ring of this male element when the male and female elements are coupled. 
   Depending on the forms of embodiment under consideration, this part may be in one piece with or added on a principal part of the valve adapted to obturate an inner conduit of the female element. 
   In addition, the part adapted to be engaged in the inner volume of the body of a male element of the connection is advantageously provided with an outer peripheral bevel for abutment against an O-ring, this bevel being convergent in a direction opposite to a zone of tight abutment of the valve on the body of the female element. 
   The vertex angle of this bevel may present a value included between 60 and 175°, preferably between 80 and 160°, and preferably still, of the order of 120°. 
   In a variant embodiment, in place of the bevel, the afore-mentioned part may be shaped as a portion of torus. 
   This invention also relates to a quick connection for removably joining two pipes through which a fluid under pressure circulates, this connection comprising two elements, male and female, adapted to fit in each other axially, the male element being equipped with an O-ring disposed in a housing made in an inner surface of the body of this element, while the female element is as described hereinabove. 
   Advantageously, in the absence of the O-ring in the housing of the male element, the coupling of the male and female elements does not lead to the valve moving in the sense of opening. 
   Finally, this invention relates to an installation for filling automobile vehicle tanks with gas under pressure, each equipped with a male connection element provided with an O-ring disposed in a housing made on an inner surface of a body of this male element, this installation itself being equipped with a female connection element adapted to receive, fitted therein, one of the afore-mentioned male connection elements and provided with a closure valve. This installation is characterized in that the female element is as described hereinabove. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood and other advantages thereof will appear more clearly in the light of the following description of two forms of embodiment of a female element, of a connection, and of a part of an installation in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings, in which: 
       FIG. 1  is an axial section through a male element and a female element of a connection according to the invention, in uncoupled configuration. 
       FIG. 2  is a section similar to  FIG. 1 , showing the connection in coupled configuration and when the male element is equipped with an O-ring. 
       FIG. 2A  is a view on a larger scale of detail D in  FIG. 2 . 
       FIG. 3  is a section similar to  FIG. 2  in the absence of the O-ring in the male element of the connection, and 
       FIG. 4  is a view similar to  FIG. 2A  for a connection and an element in accordance with a second form of embodiment of the invention. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring now to the drawings, the connection shown in  FIGS. 1 to 3  comprises a female element or connector A and a male element or connector B respectively connected 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). 
   In the present case, the element A belongs to an installation such as a service station and is connected via the pipe C 1 , which is flexible, to a reservoir of liquefied petroleum gas. As for the connector B, it is mounted on an automobile vehicle and connected to the fuel tank of that vehicle. According to an aspect of the invention (not shown), the connector B may be equipped with an internal closure valve. 
   The body  1  of the female element A is of substantially cylindrical and circular shape, centred on an axis X A –X′ A  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 A –X′ A . The valve  2  is equipped with an O-ring  21  intended to come into abutment against an inner shoulder  12  of the body  1  in order to obturate the conduit  11 . The valve  2  is provided with an outer radial flange  22  on which a spring  3  in abutment against a second shoulder  13  of the body  1  exerts an elastic effort F 3  of closure of the valve  2 . The outer shape of the valve  2  is cylindrical, with circular base centred on axis X A –X′ A . It is provided with an axial bore  23  and with a plurality of radial bores  24 , of which two are visible in the Figures. 
   The valve  2  comprises a head  25  disposed in the conduit  11 , upstream of the shoulder  12 . It also comprises a rod  26  disposed downstream of the shoulder  12  and of which  26   a  denotes the end or “head” which projects with respect to the flange  22 , opposite the head  25 . 
   Between the shoulders  12  and  13 , the body  2  is provided with a groove  14  for receiving an O-ring  15  against which the rod  26  bears. 
   A manoeuvring sleeve  4  is disposed around the body  1  and elastically loaded by a spring  5  towards a position where it exerts a centripetal effort on balls  6 . Only one ball is visible in the Figures. In practice, the female element comprises a plurality of balls distributed about axis X A –X′ A . In a variant, the balls may be replaced by fingers or pawls performing, like the balls  6 , a function of locking the male connector in the coupled configuration shown in  FIG. 2 . 
   The outer shape of the body  101  of the male element B is substantially cylindrical and circular, centred on an axis X B –X′ B  which is intended to merge with axis X A –X′ A  when elements A and B are in coupled configuration. The body  101  defines a conduit  111  for circulation of gas under pressure and is provided with a groove  116  for receiving the balls  6  with a view to locking the elements A and B in coupled configuration. 
   The body  101  is also provided with an inner radial groove  117  which borders the end part  111   a  of the conduit  111  closest to its opening and in which an O-ring  102  is disposed. This O-ring  102  aims at ensuring an efficient insulation between the assembly constituted by conduits  11  and  111 , on the one hand, and the ambient atmosphere, on the other hand, when elements A and B are coupled. 
   As the groove  117  is made inside the body  101 , the O-ring  102  is relatively protected from the mechanical and chemical aggressions coming from the outside. 
   The groove  117  is adjacent an inner radial shoulder  112  of the body  101  and d denotes the distance between this shoulder  112  and the front face  118  of the body  101 . 
   The head  26   a  of the rod  26  is provided with an outer peripheral bevel  26   b  of which the vertex angle α has a value of the order of 120°. In practice, the angle α may have a value included between 60 and 175°, preferably between 80 and 160°, and preferably still, of the order of 120°. 
   When the elements A and B are to be fitted in each other, they are subjected to a movement of approach represented by arrow F 1  in  FIG. 1 , this making it possible to attain the configuration of  FIG. 2  where the head  26   a  has penetrated in the end  111   a  of the conduit  111 . In this configuration, the bevel  26   b  bears against the O-ring  102  and exerts thereon an axial effort F 2 . Due to its stiffness, which is greater than that of the spring  3 , the O-ring  102  exerts on the bevel  26   b  an effort of reaction F′ 2  which makes it possible to push the valve  2  against the effort F 3 , the valve  2  in that case attaining the position of  FIG. 2  where the channels  24  and  23  allow the flow of gas under pressure from the upstream part of the conduit  11  towards the conduit  111 , as represented by arrows E. 
   The value of the angle α influences the deformation of the O-ring  102 , its tightness and its durability. An angle α of the order of 120° gives satisfactory results and makes it possible to conciliate a clear-cut abutment of the head  26   a  on the O-ring  102 , without degradation of the latter, with a clear-cut opening of the valve  2 . 
   In the absence of O-ring  102  in the groove  117 , and as shown in  FIG. 3 , the front face  26   c  of the end  26   a  does not bear against the shoulder  112 , with the result that the valve  2  remains in position of tight abutment against the shoulder  12  which serves as seat therefor. 
   To that end, the length  1   26  of the end  26   a  is less than the sum of the distance d and of the distance e between the front face  118  of the element B and the flange  22 , when the valve is in closed configuration. 
   In view of the foregoing, a secured functioning of the connection formed by elements A and B is obtained, insofar as the valve  2  is efficiently displaced by the O-ring  102  when the elements A and B are coupled, while, in the absence of the O-ring  102 , the valve remains in abutment on its seat  12 , this avoiding the risks of leakage and allowing an efficient detection of the absence of O-ring. 
   The invention has been represented when used in a service station for filling automobile vehicle tanks, but may be employed in other domains where similar problems are likely to occur. 
   In the example shown, the head or end  26   a  is in one piece with the head  25  and the rod  26  of the valve  2 . In a variant embodiment, this head may be added on this rod and fixed by any appropriate means, particularly by adhesion, screwing or welding. 
   The head  26   a  is not necessarily equipped with a bevel as shown in the Figures with reference  26   b . In the case shown in  FIG. 4 , the zone of transition  26   b  between its front face  26   c  and its outer radial surface  26   d  is preferably rounded, with a radius of curvature R greater than 0.3 mm, avoiding the O-ring  102  being marked by the head  26   a . The zone of transition  26   b  is in that case in the form of a portion of torus. 
   In addition, the diameter of the rod  26  in the vicinity of the channels  24 , i.e. in the vicinity of the shoulder  12  and of the O-ring  15 , is advantageously greater than the diameter of the head or end  26   a . In this way, the resultant of the pressure of the gas in the coupled connection tends to close the valve  2 . In practice, the diameter of the rod  26  may be slightly greater than that of the head  26   a , for example 0.2 mm.

Technology Classification (CPC): 5