Abstract:
A fluid communication device including a tubular body which enables the circulation of a fluid and which has an end piece that is connectable to a plug-in pipe having an outer annular locking groove. An assembly head includes a receiving chamber in which an end piece of the tubular body is mounted. The assembly head includes a U-shaped locking element having two arms that are inserted into the receiving chamber. An intermediate ring is slidably mounted in the receiving chamber to achieve a pre-opening of the locking element just before the plug-in pipe reaches a position in which it engages with the end piece.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase Patent Application based on International Application No. PCT/EP2013/065103 filed Jul. 17, 2013, which claims priority to French Patent Application No. 1257124 filed Jul. 23, 2012, the entire disclosures of which are hereby explicitly incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of fittings for fluid conveyance, and more specifically a fluid communication device comprising a tubular body permitting circulation of a fluid and having a tubular end piece extending in a given axial direction, said tubular end piece being intended to be connected by axial insertion to a plug-in pipe having an outer annular locking neck, said device further comprising an assembly head in which the tubular end piece is mounted, said assembly head comprising a receiving chamber that is coaxial with the tubular end piece and is adapted to receive said plug-in pipe so as to connect it to the tubular end piece, said assembly head also comprising a U-shaped locking element with two arms that insert into said receiving chamber in an insertion direction that is perpendicular to said axial direction, said two arms being adapted to spread apart elastically in said receiving chamber in a direction transverse to said axial direction when the pipe is displaced axially in the chamber to a position of abutment in which it is fully connected to the tubular end piece, said arms further being adapted to engage in said annular neck of the plug-in pipe by moving closer together when said plug-in pipe has reached its position of abutment with respect to the tubular end piece, so as to lock the plug-in pipe in position in the assembly head. 
     2. Description of the Related Art 
     This type of fluid communication device is widely used to quickly connect all types of fluid pipes to a flange, particularly in the automotive industry for the connection of fuel injectors, filters, and radiators. In some cases, the production of these flanges by machining may necessitate several rework operations, owing to the complexity of the flanges. To reduce the cost of their production, however, manufacturers of these flanges no longer do finishing work on the radii and chamfers of the pipes to be connected, and the latter consequently may damage the seals provided in the communication devices such as that defined above. There may also be damage to the locking element of the communication device if the insertion forces required to insert the pipe in the communication device are too high, due to binding or catching of the elements that are to be inserted one inside the other. 
     Published patent U.S. Pat. No. 7,445,249 describes a plug-in pipe with an annular rib that serves to pre-open a U-shaped locking element in a fluid communication device. As noted above, however, manufacturers of flanges with plug-in pipes are in fact trying to reduce the complexity of such pipes. 
     SUMMARY OF THE INVENTION 
     The present invention provides a fluid communication device designed with a mechanism for pre-opening a locking element. 
     To this end, the subject matter of the invention is a fluid communication device comprising a tubular body permitting circulation of a fluid and having a tubular end piece extending in a given axial direction, said tubular end piece being intended to be connected by axial insertion into a plug-in pipe having an outer annular locking neck, said device further comprising an assembly head in which the tubular end piece is mounted, said assembly head comprising a receiving chamber that is coaxial with the tubular end piece and is adapted to receive said plug-in pipe so as to connect it to the tubular end piece, said assembly head also comprising a U-shaped locking element with two arms that insert into said receiving chamber in an insertion direction that is perpendicular to said axial direction, said two arms being adapted to spread apart elastically in said receiving chamber in a direction transverse to said axial direction when the pipe is displaced axially in the chamber to a position of abutment in which it is fully connected to the tubular end piece, said arms further being adapted to engage in said annular neck of the plug-in pipe by moving closer together when said plug-in pipe has reached its position of abutment with respect to the tubular end piece, so as to lock the plug-in pipe in position in the assembly head, characterized in that further provided is an intermediate ring, which is mounted in said receiving chamber so as to able to slide in said axial direction in order to effect a pre-opening of the locking element, said intermediate ring being adapted to be pushed axially by said plug-in pipe when the latter is displaced in said receiving chamber toward the tubular end piece, said intermediate ring having chamfers that act to elastically spread apart the two arms of the locking element just before said plug-in pipe reaches its position of abutment. 
     The idea on which the invention is based is, therefore, to provide a sliding intermediate ring that accompanies the insertion of the pipe in the communication device all the way to its position of abutment on the tubular end piece, thereby reducing the stresses of mounting the pipe on the tubular end piece. 
     The fluid communication device according to the invention can advantageously have the following features: 
     it comprises an elastic biasing element mounted in said receiving chamber in such a way as to act in opposition to said axial displacement of the intermediate ring in order to return the latter to an initial position when the latter is not being pushed by a pipe 
     said intermediate ring comprises reference tongues that are visually apparent from the outside of the assembly head when said pipe is locked on the tubular end piece. 
     In one form thereof, the present invention provides a fluid communication device including a tubular body permitting circulation of a fluid and having a tubular end piece extending in a given axial direction, the tubular end piece being intended to be connected by axial insertion into a plug-in pipe having an outer annular locking neck, the device further including an assembly head in which the tubular end piece is mounted, the assembly head including a receiving chamber that is coaxial with the tubular end piece and is adapted to receive the plug-in pipe so as to connect it to the tubular end piece, the assembly head also including a U-shaped locking element with two arms that insert into the receiving chamber in an insertion direction that is perpendicular to the axial direction, the two arms being adapted to spread apart elastically in the receiving chamber in a direction transverse to the axial direction when the pipe is displaced axially in the chamber to a position of abutment in which it is fully connected to the tubular end piece, the arms further being adapted to engage in the annular neck of the plug-in pipe by moving closer together when the plug-in pipe has reached its position of abutment with respect to the tubular end piece, so as to lock the plug-in pipe in position in the assembly head, characterized in that further provided is an intermediate ring, which is mounted in the receiving chamber so as to be able to slide in the axial direction in order to effect a pre-opening of the locking element, the intermediate ring being adapted to be pushed axially by the plug-in pipe when the latter is displaced in the receiving chamber toward the tubular end piece, the intermediate ring having chamfers that act to elastically spread apart the two arms of the locking element just before the plug-in pipe reaches its position of abutment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an exploded perspective view of the fluid communication device according to the invention; 
         FIGS. 2 and 3, 4 and 5, 6 and 7, and 8 and 9  are axial sectional views along two axial planes, successively illustrating various steps in the assembly of the fluid communication device of  FIG. 1 ; and 
         FIGS. 10 and 11  are radial sections of the fluid communication device of  FIG. 1  in which the sectional plane passes through the locking element, particularly through plane AA of  FIG. 9 , and which illustrate the respectively unlocked and locked positions of the locking element. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
     DETAILED DESCRIPTION 
     Turning now to the figures, particularly  FIG. 1 , the fluid communication device  1  according to the invention comprises a tubular body  2 , seals  3 , an intermediate ring  4 , an elastic biasing element  5 , locking means  6  and a hollow head forming a sleeve  7 . The fluid communication device  1  is intended to receive a plug-in fluid pipe  8  (visible in  FIGS. 4 to 11 ). 
     The body  2  has a tubular end piece  20  that extends in an axial direction A and, here, two stepped end pieces  21  with which the tubular end piece  20  forms a T. Passing axially through the tubular end piece  20  and the stepped end pieces  21  are pipes  22  that communicate with one another and that also form a T. The body  2  can, of course, have any other suitable shape. Thus, a fluid can circulate in the pipes  22  of the tubular end pieces  20  toward one or both of the stepped end pieces  22  and vice versa. The tubular end piece  20  is cylindrical overall and has an outer circular slot  23  provided toward its free end and intended to receive an annular gasket  3  that constitutes the sealing means after the fluid pipe  8  has been fitted onto the tubular end piece  20 . The tubular end piece  20  additionally comprises longitudinal ribs  24 , four of them in the example, which are distributed over the periphery of the tubular end piece  20  and whose function will be explained hereinbelow. These longitudinal ribs  24  extend over only a portion of the tubular end piece  20 , opposite the free end of the tubular end piece  20 . The ends of the longitudinal ribs  24  merge with the cylindrical portion of the tubular end piece  20  via inclined ramps  25  (visible in  FIG. 1 ) whose function will be explained hereinbelow. 
     The intermediate ring  4  comprises a guide ring  40  (visible in  FIG. 1 ) having an inner diameter that is slightly larger than the outer dimensions of the longitudinal ribs  24  of the tubular end piece  20  on which it is mounted so as to be able to slide. On its outer face, the guide ring  40  has a cylindrical portion  41 , followed by a chamfer  42  that flares with increasing distance from the cylindrical portion  41 . The chamfer  42  is disposed such that when the intermediate ring  4  is fitted onto the tubular end piece  20 , the chamfer  42  extends away from the free end of the tubular end piece  20 . The chamfer  42  is at least partially annular. In the example shown, the chamfer  42  has two separate concentric portions. The intermediate ring  4  further comprises two separate diametrically disposed tongues  43 , which are integral to the guide ring  40 . These tongues  43  are provided between the portions of the chamfer  42  and are inscribed in a cylinder of larger diameter than that of the chamfer  42 . The tongues  43  are also elastically deformable. The free end of each tongue  43  is provided with a radial lug  44  whose function will be explained hereinbelow. Once the intermediate ring  4  has been fitted onto the tubular end piece  20 , the tongues  43  create an annular seat  45  between the intermediate ring  4  and the tubular end piece  20 . The intermediate ring  4  can slide on the tubular end piece  20  in direction A, between a frontal position in which it is close to the free end of the tubular end piece  20  and a dorsal position in which it is far from the free end of the tubular end piece  20  and close to the stepped end pieces  21 . 
     In the example shown, the elastic biasing element  5  is a compression spring having coils whose inner diameter is slightly larger than the outer dimensions of the longitudinal ribs  24  and whose outer diameter is slightly smaller than the diameter of the annular seat  45  of the intermediate ring  4 . Thus, the elastic biasing element  5  can be fitted onto the tubular end piece  20  and partially seated in the annular seat  45  of the intermediate ring  4 . One end of the elastic biasing element  5  bears against the edge of the guide ring  40  of the intermediate ring  4 , and the other against a radial shoulder  26  of the body  2 . The elastic biasing element  5  tends to urge the intermediate ring  4  toward an initial resting position that corresponds to the frontal position. 
     The locking means include an elastically deformable, U-shaped locking element  6 , for example formed of spring wire. The two arms or branches  60  of the U of the locking element  6  can thus be forced away from each other in a direction transverse to direction A toward an unlocked position, before being released and coming elastically back together into a locked position. 
     In its frontal mouth, the sleeve  7  has an inner orifice  70  whose shape and dimensions are substantially complementary to those of the intermediate ring  4 . Thus, the sleeve  7  includes longitudinal slots  71  that are designed to allow the tongues  43  of the intermediate ring  4  to pass. These longitudinal slots  71  serve to guarantee the angular position of the intermediate ring  4  relative to the sleeve  7  during assembly. The distance between these longitudinal slots  71  is smaller than the distance separating the radial lugs  44 . Thus, the tongues  43  must be bent toward one another in order to get past the longitudinal slots  71 . In alignment with these longitudinal slots  71  and passing through the medial portion of the sleeve  7  are two radial windows  72 , through which the tongues  43  are visible when the intermediate ring  4  is in its dorsal position. When the sleeve  7  has been fitted onto the tubular end piece  20 , the sleeve  7  and the tubular end piece  20  define between them an annular chamber  73  in which the intermediate ring  4  seated so as to be able to slide. This annular chamber  73  is coaxial with the tubular end piece  20  and is intended to receive the end of a plug-in fluid pipe  8  that fits onto the free end of the tubular end piece  20  by axial insertion accompanied by axial pushing of the intermediate ring  4 . The inner orifice  70  of the sleeve  7  further comprises inner radial recesses  74 , which frontally delimit radial windows  72  and against which the radial lugs  44  of the tongues  43  of the intermediate ring  4  are to bear. The sleeve  7  further comprises two radial openings  75 , which are located diametrically opposite each other and open into the inner orifice  70 . The radial openings  75  are disposed angularly between the longitudinal slots  71 . These radial openings  75  are intended to receive the branches  60  of the locking element  6  and are edged by radial ribs  76  (visible in  FIG. 1 ) that guide the branches  60  of the locking element  6  between its locked and unlocked positions. Remote from the longitudinal slots  71 , the sleeve  7  comprises two mutually separate, incurvate, longitudinal wings  77  (visible in  FIG. 1 ) that prolong the inner orifice  70 . These longitudinal wings  77  are in alignment with the longitudinal slots  71  and are intended to straddle the intersection between the stepped end pieces  21  of the body  2  in order to orient the sleeve  7  angularly relative to the body  2  during assembly. 
     The means of communication used is a fluid pipe  8  with a main orifice  80  passing through it and an outer diameter substantially equal to that of the maximum diameter of the intermediate ring  4  where the chamfer  42  is greatest. The fluid pipe  8  used is also provided with an annular neck  81 —here, a circular one—which is intended to receive the branches  60  of the locking element  6 . The end of the fluid pipe need not have any particular shape. 
     Turning now to  FIGS. 2 and 3 , prior to the use of the fluid communication device  1 , the annular gasket  3 , the elastic biasing element  5 , the intermediate ring  4 , the sleeve  7  and the locking element  6  are assembled on the body  2 . During assembly, the elastic biasing element  5  is guided over the tubular end piece  20  by the longitudinal ribs  24  and the inclined ramps  25 , facilitating insertion. To insert the intermediate ring  4  into the sleeve  7 , the tongues  43  are elastically deformed toward one another to enable the radial lugs  44  to get past the longitudinal slots  71 . When the radial lugs  44  are opposite the radial windows  72 , the tongues  43  relax. The intermediate ring  4  is then locked in the sleeve  7  by its radial lugs  44  and the inner radial recesses  74  of the sleeve  7 . In this pre-assembled state of the fluid communication device  1 , the branches  60  of the locking element  6  are in locked position, projecting into the annular chamber  73  and bearing against the guide ring  40  of the intermediate ring  4 . The intermediate ring  4  is held in its frontal position by the elastic biasing element  5 . The angular position of the intermediate ring  4  relative to the sleeve  7  is guaranteed by the tongues  43  and the radial windows  72 . In addition, the angular position of the sleeve  7  relative to the body  2  is guaranteed by the longitudinal wings  77  and the stepped end pieces  21 . 
     Referring now to  FIGS. 4 and 5 , when a fluid pipe  8  is to be fitted on, it is first positioned within the axis of the tubular end piece  20  and is then inserted axially over the tubular end piece  20  and into the inner orifice  70  of the sleeve  7 . In the process, the free end of the fluid pipe  8  comes into contact with the side of the intermediate ring  4 . Leaktightness between the fluid pipe  8  and the tubular end piece  20  is ensured by the annular gasket  3 . Turning to  FIGS. 6 and 7 , the free end of the fluid pipe  8  continues to be inserted axially, which causes the intermediate ring  4  to be displaced in the annular chamber  73 , the elastic biasing element  5  to be gradually compressed, and the branches  60  of the locking element  6  to slide over the guide ring  40 . The locking element  6  is still in locked position at this point. The insertion of the free end of the fluid pipe  8  continues. The branches  60  of the locking element  6  that are in contact with the chamfer  42  are elastically spread apart transversely to direction A until the chamfer  42  has been cleared. As illustrated by  FIG. 10 , the branches  60  of the locking element  6  are then in unlocked position, in which they are separated by a distance that allows the free end of the fluid pipe  8  to pass without stress. During this step, the compression of the elastic biasing element  5  is increased. The insertion of the free end of the fluid pipe  8  proceeds further. With reference to  FIGS. 8, 9 and 11 , when the branches  60  of the locking element  6  are opposite the circular neck  81  of the fluid pipe  8 , they relax into their locked position, in which they are seated in the circular neck  81  and prevent the fluid pipe  8  from being withdrawn from the sleeve  7  and the tubular end piece  20 . The fluid pipe is then in abutment with the tubular end piece. Leaktightness between the fluid pipe  8  and the tubular end piece  20  continues to be ensured by the annular gasket  3 . In this locked position, the tongues  43  of the intermediate ring  4  are visible through the radial windows  72  of the sleeve  7 . Visual inspection of the positions of the tongues  43  in the radial windows  72  makes it possible to ascertain that the fluid pipe  8  is properly connected and effectively locked. The fluid pipe  8  is solidly fitted to the fluid communication device  1 . 
     If necessary, the fluid pipe  8  can easily be removed from the fluid communication device  1  by pressing the tongues  43  toward one another so as to free the radial lugs  44  from the inner radial recesses  74 . The elastic biasing element  5  can then be freed by forcibly pulling on the fluid pipe  8  to get the branches  60  of the locking element  6  to come out of the circular slot in the circular neck  81  of the fluid pipe  8 . The elastic biasing element  5  acts in opposition to the axial displacement of the intermediate ring toward the tubular end piece and tends to maintain the intermediate ring  4  in its frontal initial position when the latter is not being pushed by the plug-in fluid pipe. Thus, after being removed, the fluid pipe  8  can again be connected to the fluid communication device  1  as described above. 
     As is clearly apparent from the foregoing description, the fluid communication device  1  according to the invention makes it possible to limit the force that must be exerted in fitting on the fluid pipe  8 . This is because the intermediate ring  4 , particularly with the chamfer  42 , makes it easier to get the fluid pipe  8  past the locking element  6  without requiring any particular shape for the end of the fluid pipe  8 . It goes without saying that the present invention is in no way limited to the foregoing description of the embodiment, which is susceptible of some modifications without thereby departing from the scope of the invention. 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.