CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is continuation of co-pending International Application No. PCT/FR2008/001040 filed Jul. 16, 2008, which designated the United States, and which claims priority to French Patent Application 0705418, filed Jul. 25, 2007, the disclosure of each of which is expressly incorporated herein by reference. 


   BACKGROUND OF THE INVENTION 
   The present invention relates to a connector with an indicator, and more precisely to a connector also known as a “quick” connector or coupling. 
   Certain automobile equipment manufacturers require ways for ensuring that fuel lines are properly installed, in particular to prevent the risk of couplings being incompletely connected. 
   Thus, certain type couplings that are locked manually typically employ U-shaped clips that enable the user to lock the coupling halves only when one halve is properly in place in the other. 
   Quick couplings, however, lock automatically. It thus is required that the coupling itself indicates that the connection has been properly made. For this purpose, an indicator part is used that may be ejected or extracted from the coupling at the end of connection. 
   Such couplings with indicators are shown, for example, in EP 712473; EP 959290; and EP 901592, relating to ejectable indicator parts, and in U.S. Pat. No. 6,722,703 and EP 1734299 relating to indicator parts that are extractable. 
   These solutions may not be ideal as involving a waste management issue for the user. Such solutions also run the risk that indicator part may be lost or forgotten in the engine compartment of a vehicle where it may give rise to noise or may even melt and foul the engine even before the vehicle is sold. 
   In addition, the indicator function of such couplings is disable after the first use such that when a second connection is performed later, such as during a maintenance operation that requires disconnection, any subsequent connection no longer benefits from this indicator function as the indicator part has been separated from the coupling on the first occasion that is it used. 
   U.S. Pat. No. 7,316,425 describes a coupling with an indicator in which the indicator is not separable from the components of the coupling, and in particular from the locking member. Nevertheless, this coupling requires an action to be performed by the operator. 
   Thus, there is believed to exist a need for a quick coupling that incorporates a function of automatically signaling proper connection, and which function is permanent, inseparable from the components of the coupling itself so as to be reusable after disconnection, and constitutes a mark that is visually highly contrasted relative to the other components of the coupling. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a quick connector with an indicator. The connector includes:
         a female part having a staged bore with a section of larger diameter;   a male part having a collar; and   a latch which may be in the form of a ring mounted to slide radially in a housing formed in the female part.
 
With the larger diameter section of the female part being capable of receiving the outer collar of the male part of the connector beyond the latch ring, the latch ring is movable against a resilient return member between a stable, first position for locking where its opening for passing the collar is off-center relative to the axis of the large-diameter section of the bore, and an unstable, second position where the opening is substantially coaxial with the section of such bore.
       

   The latch ring is fitted on its rear face with a backing ring possessing an opening of the same diameter as the opening in the latch ring. The backing ring is free to slide relative to the latch ring parallel to the sliding direction thereof in the female part. The backing ring is held relative to the latch ring in a position in which the two openings lie on a common axis by means of at least one tab that is folded onto the visible surface portion of the latch ring, with movement of the latch ring relative to the backing ring from such position causing the tab to be stood up at the surface of the latch ring. 
   This arrangement has several advantages. One lies in the fact that the length of the tab can be considerable, and its movement that results from the ring moving relative to the backing ring, even by only a small amount, is constituted by a tilting movement so that the tab stood up at the surface of the latch ring, and thus at the outside surface of the coupling, constitutes a kind of small flag (the indicator) that is of dimensions that are not negligible, and providing it is of a bright color or strongly contrasted with the color of the body of the coupling, it provides a clear indication of the (good) state of the connection that has been made. Another advantage lies in the fact that the indicator is held captive and therefore does not constitute waste. 
   With the invention, when the coupling is not achieved, the folding down of the tab against the above-mentioned surface portion of the latch ring causes the backing ring to be recentered relative to the latch ring. This provides an indicator that is reusable or that can be initialized. 
   In an embodiment of the invention, the backing ring has two tabs suitable for folding down on the visible surface of the latch ring, with the tabs moving as mirror images of each other. 
   In another embodiment, the tab can be folded down is a single tongue, and its movement is contained substantially in a plane perpendicular to the axis of the staged bore. 
   For reasons of appearance, it is advantageous for the visible surface of the latch ring to include housings for receiving the above-mentioned tab(s). 
   The invention thus seeks to provide a coupling similar in particular to the coupling described in document FR-A-2705430, but with a member for signaling the state of its connection, which member is captive and highly visible in each of its two states. 
   The present invention, accordingly, comprises the construction, combination of elements, and/or arrangement of parts and steps which are exemplified in the detailed disclosure to follow. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein: 
       FIG. 1  is an axial section view of the female part of a connector in accordance with the state of the art as shown in FR-A-2705430; 
       FIG. 2  is an axial section view of the female part of a  FIG. 1  connector fitted with the indicator in accordance with the invention; 
       FIG. 3  is an outside view of the latch ring associated with the backing ring; 
       FIG. 4  is a section view of the connector of the invention indicating a good connection; 
       FIG. 5  is an outside view of  FIG. 4 ; 
       FIG. 6  is an outside view of a variant embodiment of the backing ring of the invention; 
       FIG. 7  is a section view of another embodiment of the connector of the invention; 
       FIG. 8  is an outside view of the latch ring implemented in  FIG. 7 ; and 
       FIG. 9  is an outside view showing the backing ring implemented in  FIG. 4 . 
   


   The drawings will be described further in connection with the following Detailed Description of the Invention. 
   DETAILED DESCRIPTION OF THE INVENTION 
   With reference to  FIG. 1 , a connector of the invention comprises, in known manner, a female part  1  that is subdivided into a plurality of sections along a central longitudinal axis, L. A first section  2  possesses an internal channel  3  and external means  4  forming a serrated spigot for insertion into a tube (not shown). The second section  5  of the part  1  has a bore  6  of diameter designed to receive the nose of an endpiece  7  ( FIG. 4 ) that forms the male part of the connector. 
   The third section  8  of the female part  1  has a bore  9  of diameter larger than that of the bore  6  in order to receive two O-rings  10  and an insert  11  for blocking them. The inside diameter of the insert is equal to the diameter of the bore  6 . Finally, the female part  1  has a third section  12  has a bore  13  of an inside diameter that is still greater than that of the preceding bore so as to be capable of freely passing a collar  14  carried by the endpiece  7  ( FIG. 4 ). At its end open to the outside, the last section  12  of the female part  1  has a latch for preventing the endpiece  7  being extracted once it has been properly inserted in the female part  1 . This latch is constituted by a ring  15  capable of sliding radially in the female part  1  in an open housing  1   a  formed therein, and it has two outer resilient spring legs, commonly referenced at  16 , that tend to shift the axis of the bore inside the ring  15  relative to the bore  13 . The portion of this bore inside the ring  15  situated beside the legs  16  is in the form of a conical surface  17  with the apex of the cone situated beside the other sections of the bore, such that when the collar  14  goes past, such surface forms a ramp for realigning the axes of the bore in the ring  15  and of the bore  13  in the part  1 . The ring  15  can then move against the effect of the resilient spring legs  16  until the collar  14  is received in the bore  13  beyond the ring  15 . 
   The legs  16  then relax and the ring  15  returns to its free position that is off-center relative to the bore  13 , and one of its flanks comes into contact with the rear flank of the collar  14  and constitutes an abutment opposing extraction of the endpiece  7 . 
     FIGS. 2 and 3  show the dispositions that are specific to one embodiment of the invention. In  FIG. 2 , the housing  1   a  for the ring  15  is shown to also receive a backing ring  20 . With reference to  FIG. 3 , backing ring  20  is mounted in slideways  21  and  22  on the ring  15 , running along its face that faces towards the bore  12  ( FIG. 2 ). The backing ring  20  possesses an opening  23  of the same diameter as the opening of the ring  15 . This opening  23  is held on the axis of the ring  15  by a hook  24  ( FIG. 2 ) that upwardly limits movement of the backing ring  20  relative to the ring  15 , and by two tabs  25  and  26  forming parts of the backing ring, being connected thereto by bridges  27  and  28  that are flexible and of very small dimensions such that the tabs  25  and  26  constitute fasteners for fastening the backing ring to the ring when the tabs are pressed down against the uncovered portion of the outside surface  15   a  of the ring  15 . 
   More precisely, the ring  15  includes setbacks or housings  15   b  and  15   c  in the surface  15   a , into which the tabs  25  and  26  can be placed. In this state, as shown in  FIG. 3 , the tabs  25  and  26  hold the backing ring against any tendency to slide downwards, i.e. towards the resilient spring legs  16 . The retention force can be overcome by causing the backing ring  20  to slide downwards under a force that is smaller than that developed by the spring legs  16  on the ring  15 . In this movement, the tabs escape from their housings and are raised so as to penetrate somewhat into side slots in the ring  15  along the slideways  21  and  22 . In this state, the tabs  25  and  26  clearly project out from the body of the first part  1  ( FIG. 2 ) of the connector like small, upwardly-extending flags. Such projections of the tabs  25  and  26  then constitute an indication that the backing ring  20  is offset downwards relative to the ring  15 . 
   The dimensions of each of the tabs  25  and  26  may be designed to be large so that the relative movement of the ring and the backing ring through about one or two millimeters becomes transformed into a movement of much greater amplitude and results in projections from the female part  1  of the connection that are of a size that is much greater than the value of the amplitude of the movement that gives rise to their existence. These “flags” can then easily be identified by optical inspection equipment, such as cameras. 
   This condition is shown in  FIGS. 4 and 5 , where the connector formed by the coupling of the female part  1  and the male endpiece  7  male part is shown in service. The male endpiece  7  is received inside the female part  1  of the connector and is pushed in, as may be seen in  FIG. 4 , far enough for the collar  14  to be located beyond the ring  15 . The extent to which endpiece  7  can be pushed in is limited by the insert  11  retaining the O-rings, which insert  11 , unlike in  FIG. 1 , occupies practically all of the bore  13 . When in abutment in this way, the collar  14  lies in the opening  23  of the backing ring  20 , which is of diameter that is slightly greater than that of the collar  14 . Under the effect of the spring legs  16 , the ring  15  is raised, while the backing ring  20  is held down where it was entrained by the ring  15  by means of the hooks  24  when the collar  14  was passing through the ring  15 , with the collar pushing it downwards by acting on the ramp  17 . The rise of the ring  15  causes the tabs  25  and  26  to be stood up out from their housings  15   b  and  15   c , raising them as flags, as explained above. The ring  15 , raised behind the collar  14 , then does indeed act as a latch. 
   If the operator desires to disconnect the connector, the operator presses on the surface  15   a  ( FIG. 5 ) of the ring  15 . The collar  14  can then pass back through the latch ring  15  and the connector is disassembled. The operator can then put the tabs  25  and  26  back into the housings  15   b  and  15   c . The indicator is thus cocked or reinitialized, ready to perform its function once more on the next connection. 
     FIG. 6  shows a variant embodiment of the backing ring  20  in which the two tabs  25  and  26  ( FIG. 3 ) are replaced by a single, longer tab  29  that therefore projects further from the body of the connector when it is stood up by the relative off-centering of the two rings  15  ( FIG. 3) and 20 . 
   In  FIG. 7 , the connector that is shown in section possesses a ring  15  shown in an outside view in  FIG. 8 , and also a backing ring  20 , shown in an outside view in  FIG. 9 . 
   The ring  15  is provided with a top plate  30  that serves as a disconnection pusher. This substantially horizontal plate possesses a central recess  31  for passing a tongue  32  that is hinged to the top of the backing ring  20 , which ring does not have a hook  24  in this embodiment. 
   The tongue  32  has two grooves  32   a  and  32   b  that laterally engage two respective pegs  33  provided on the flanks of the opening  31  which forms the branches of a yoke between which the tongue  32  can slide and tilt during relative movement between the ring and the backing ring. Between the branches, at their end, a cross-member  34  is provided with an orifice  34   a  for receiving a split centering button  35  at the end of the tongue  32 . As above, this relative movement results in the ring  15  rising while the backing ring  20  is blocked by the collar  14 . The pegs  33  rise, acting on the flanks of the grooves  32   a  and  32   b  so as to raise the tongue  32  with its button  35  escaping from the orifice  34   a . The tongue  32  then stands up and projects relative to the outside surface of the connector so as to form an indicator of its activated state. Unlike the tabs  25 ,  26  ( FIG. 3 ), and  29  ( FIG. 6 ) that pivot substantially about axes that are parallel to the axis of the bore  13  ( FIG. 1 ), the tongue  32  pivots about an axis that is perpendicular to that direction. As above, the indicator tongue  32  may be reinitialized after disconnection. 
   As it is anticipated that certain changes may be made in the present invention without departing from the precepts herein involved, it is intended that all matter contained in the foregoing description shall be interpreted in as illustrative rather than in a limiting sense. All references including any priority documents cited herein are expressly incorporated by reference.
A quick connector including a female part, a male part, and a latch. The latch includes a latching ring which slides within a housing of the female part, and a backing ring which is fitted on the latching ring and is slidable relative thereto. As the male part is inserted into the female part, the latching ring locks the parts and a folded tab of the backing ring is raised to provide a visual indication that male part is locked in the female part.