Abstract:
A quick safety connection for the removable joining of pipes, comprising a male connector and a female element adapted to fit and to be locked inside one another. A controlled locking mechanism is adapted to immobilized the male connector axially in a position of connection, while at least one retention member is provided to immobilize the male connector, after release of the connector by said locking mechanism, in an intermediate position of discharge of the pipe connection. The locking mechanism and retention member are controlled by a sleeve sliding around the female element. Vents and safety stops are provided to limit the movement of the sleeve under the effect of the pressure prevailing due to the discharge of the connection in the intermediate position between the female element and the sleeve.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a quick safety connection for the removable joining of pipes and, more specifically, to a so-called “double-release” quick connection. 
     DESCRIPTION OF THE RELATED ART 
     European Patent Application 0 722 063 discloses a double-release quick connection in which two rings are used, provided with elastic claw elements adapted to cooperate successively with an outer groove of a male connector in order to release this connector in two steps, allowing the discharge of the fluid contained in the downstream pipe, which avoids the whiplash movements which might prove dangerous for a user with a single-release connection. Other double-release connections are known for example from U.S. Pat. No. 5,290,009 or DE-A-27 41 512. 
     In these known devices, an outer ring or sleeve is used for controlling, on the one hand, means for locking the male connector in the female element in a position of communication of the pipes, and, on the other hand, members for retaining the connector in intermediate position of emptying or discharge of the downstream pipe. In this position of discharge, the fluid which flows from the male connector fills the inner volume of the sleeve, which has the effect of increasing the pressure prevailing in an annular chamber defined around the body of the female element and inside this sleeve. Such increase in pressure may, in at least certain configurations, induce a displacement of the sleeve corresponding to an increase in the volume of this chamber, i.e. to a reduction of this pressure. Such a displacement may have the consequence of releasing the male connector without the intervention of an operator, which may result in a violent discharge and a potentially dangerous “whiplash”. 
     It is a particular object of the present invention to overcome these drawbacks by proposing a quick safety connection in which the male connector does not risk passing automatically, i.e. without the intervention of the operator, from its position of locking in the female element to a position of complete disconnection, without retention in its position of discharge of the downstream pipe. 
     SUMMARY OF THE INVENTION 
     To that end, the invention relates to a quick connection of the type mentioned hereinbefore, which comprises means for limiting the movement of the sleeve, under the effect of the pressure prevailing in its inner volume due to the discharge of the pipe in the intermediate position, towards a position of release of the connector by the retention member. 
     Thanks to these means for limiting the movement of the sleeve, the latter cannot be displaced towards a position of release, premature and automatic, of the male connector. 
     According to a first advantageous embodiment of the invention, the means for limiting the movement of the sleeve comprise venting orifices allowing the flow of the fluid issuing from the downstream pipe, from the inner volume of the sleeve towards the outside of the connection. These vents avoid too great a rise in pressure within the sleeve, particularly in an annular chamber defined around the body of the female element. Such a pressure is therefore not capable of inducing an untimely displacement of the sleeve. The venting orifices advantageously present a total cross-section allowing the flow of the fluid issuing from this downstream pipe without substantial rise in the pressure in the inner volume of the sleeve. 
     According to a second, particularly advantageous embodiment of the invention, the means for limiting the movement of the sleeve comprise a stop adapted to cooperate with an inner heel of the sleeve, this stop being disposed in the inner volume of the sleeve. Such a stop makes it possible efficiently to limit the movements of the sleeve. According to an advantageous aspect, the stop is formed by a ring disposed around the body of the female element in an annular chamber defined between the body and the sleeve. This ring may be provided to be elastically loaded in the direction of an outer bearing surface of the body and in the direction of the heel of the sleeve. In that case, the means for elastically loading the ring may be formed by means for elastic return of the sleeve into position of engagement of the locking mechanism and/or of the retention member. 
     According to another advantageous aspect of the invention, the clearance between the body of the female element and the sleeve, downstream of the stop in the direction of flow of the fluid, in the intermediate position of the connector, is greater than the clearance between this stop and the body and/or than the clearance between this stop and this sleeve. This aspect of the invention guarantees that the pressure downstream of the stop is permanently lower than the pressure upstream of this stop, with the result that the stop is permanently subjected to a difference in pressure which tends to apply it towards the bearing surface defined on the body and towards the heel of the sleeve. 
     The known devices comprise means for locking in transfer position and means for retention in intermediate position, adapted to cooperate with a particular geometry of connector, particularly in the case of using elastic claws. Now, the connectors that may be used with the female elements may have several origins and variable geometries, with the result that the locking means and/or the manoeuvring members are not always fully efficient. In order to overcome this drawback, the retention member is formed by a ball capable of axial and radial movements in an oblong slot formed in the body. Furthermore, the locking mechanism may comprise needles mobile in oblong slots formed in the body in directions inclined with respect to the direction of introduction and of extraction of the male connector in and from the female element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood on reading the following description of an embodiment of a quick safety connection 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 showing the general arrangement of two male and female elements of a connection according to the invention, in coupled position. 
     FIG. 2 is a cross-section along line II—II of FIG. 1; I—I therein indicates the plane of section of FIG.  1 . 
     FIG. 3 is an axial section along line III—III of FIG. 1; I—I therein indicates the plane of section of FIG.  1 . 
     FIG. 4 shows, in an exploded perspective view, certain elements constituting the connection of FIGS. 1 to  3 . 
     FIG. 5 is a section similar to FIG. 1 when the male connector is placed in an intermediate position of discharge or of emptying. 
     FIG. 6 is a section along line VI—VI of FIG. 5; V—V therein indicates the plane of section of FIG.  5 . 
     FIG. 7 is a section similar to FIG. 5 when the male connector has attained its position of discharge or of emptying. 
     FIG. 8 is a section along line VIII—VIII of FIG. 7; VII—VII therein indicates the plane of section of FIG.  7 . 
     FIG. 9 is a view similar to FIG. 7 upon disconnection of the male connector from the female element of the connection, and 
     FIG. 10 is a section along line X—X of FIG. 9; IX—IX therein indicates the plane of section of FIG.  9 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings, the quick connection shown in the Figures comprises a male element A and a female element B both provided to be tubular in shape. The male element A is formed by a connector  1  whose rear part (not shown) is fluidically connected to a first pipe C 1 . Similarly, the rear part of the female element B is connected to a second pipe C 2  itself connected to a source of compressed air (not shown). The female element B is formed by a tubular body  2  inside which is slidably housed a valve  3  adapted to come into abutment against a seat  4 , formed by an elastomer ring immobilized between an inner bush  5  and an outer bush  6  on which the pipe C 2  is connected, bushes  5  and  6  being disposed inside a central bore  2   a  of the body  2 . An O-ring  7  is also provided in this central bore in order to abut against the outer radial surface of the connector  1  when the connection is in coupled position, as shown in FIGS. 1 and 3. 
     Two needles  10  and  11  are provided to lock the connector  1  inside the body  2  in the position of FIGS. 1 and 3. These needles are received in an outer peripheral groove  1  a of the connector  1 , bordered by an outer peripheral flange  1   b . The needles  10  and  11  are mobile inside oblong slots  20  and  21  made in the body  2  and inclined with respect to the central axis X-X′ of the male and female elements A and B which defines the direction of introduction and of extraction of the male connector A in and from the female element B. 
     During introduction of the connection  1  in the body  2 , the flange  1   b  pushes the needles  10  and  11  inside the slots  20  and  21  until the front face  1   c  of the connector  1  abuts against the corresponding face  3   c  of the valve  3 . Due to the continuing movement of introduction of the connector  1 , the valve is detached from its seat  4 , which allows the flow of the air traversing the connector, from the upstream pipe C 2  towards the downstream pipe C 1 , as represented by arrows F in FIGS. 1 and 3. 
     A locking ring  30  is disposed around the body  2  and shaped so that the ends of the needles  10  and  11  are in simple abutment against a face  30   a  of the ring  30  facing the opening of the bore  2   a  of the body  2 , i.e. in the direction of pipe C 1 , in the position of FIGS. 1 and 3. By its face  30   b  opposite face  30   a , the locking ring  30  is in abutment against a compression spring  31  which tends to push it towards the opening of the bore  2   a.    
     In this way, when the connector  1  is introduced in the body  2 , the needles  10  and  11  are firstly pushed inside the housings  20  and  21 , so that they move the ring  30  in the direction of the valve  3 , against the force of the spring  31 . As soon as the flange  1   b  has passed beyond the needles  10  and  11 , the elastic return effort due to the spring  31  pushes the ring  30  towards the opening of the bore  2   a  so that the needles  10  and  11  are also pushed in this direction and, taking into account the inclined nature of the slots  20  and  21 , the needles  10  and  11  are displaced in the direction of the groove  1   a  of the connector  1 . The connector  1  is thus locked in the body  2  in the position of FIGS. 1 and 3. 
     Balls  40  and  41  are housed in two oblong slots  50  and  51  made in the body  2 , parallel to axis X-X′. In the position of FIGS. 1 to  3 , the balls  40  and  41  are maintained engaged in the groove  1   a  thanks to two bearing portions  53   a  and  53   b  formed on a locking ring  53  whose function is detailed hereinafter. At the level of the balls  40  and  41 , i.e. in the plane of section of FIG. 3, the ring  30  extends in two tongues  30   c  and  30   d  which cover the bearing portions  53   a  and  53   b , with the result that a movement of the balls  40  and  41  in a radial outward direction is prevented, the balls  40  and  41  thus being firmly maintained in position in the groove  1   a.    
     A sleeve  60  is arranged around the body  2 , capable of movements of translation around this body, parallel to axis X-X′. 
     When it is necessary to open the connection, i.e. to separate the male and female elements A and B, the connector  1  is unlocked from the body  2  by exerting on the sleeve  60  an effort E 1  directed towards the rear of the female element B, i.e. towards pipe C 2 , as shown in FIGS. 5 and 6. The sleeve  60  is fast with the ring  53 , so that the displacement of the sleeve  60  towards the pipe C 2  results in a concomitant displacement of the ring  53 . The bearing portions  53   a  and  53   b  cover the balls  40  and  41  and prevent any radial movement of these balls towards the outside of the groove  1   a.    
     Sidewalls  53   c  and  53   d  of the ring  53  are in simple abutment against the needles  10  and  11 . Due to the movement of the ring  53 , the sidewalls push the needles in the direction of pipe C 2 , which also has the effect of pushing the ring  30  against the return force of the spring  31 , as is produced during the step of unlocking of the connection. Under these conditions, due to the inclination of the slots  20  and  21  with respect to axis X-X′, the needles  10  and  11  are extracted from the groove  1   a  of the connector  1 , with the result that the connector  1  may be driven or drawn towards the outside of the bore  2   a , as represented by arrow T in FIGS. 5 and 6. 
     The front face  1   c  of the connector  1  is then no longer in abutment against the face  3   c  of the valve  3 . The valve  3  is therefore applied against the seat  4  under the effect of the pressure forces prevailing in the outer bush  6 . 
     In the position of FIGS. 5 and 6, the connector  1  is retained inside the body  1  by the balls  40  and  41  which are maintained in the groove  1   a , as shown in FIG.  6 . 
     By passing from the position of FIGS. 1 to  3  to that of FIGS. 5 and 6, the connector  1  has arrived in a position of decompression or emptying of the air contained in the pipe C 1 , since the front face  1   c  of the connector  1  is separated from the valve  3  by an inner volume V whose width  1 , defined between faces  1   c  and  3   c , is non zero. 
     When the operator releases the sleeve  60 , the latter is pushed towards the opening of the bore  2   a . In effect, the spring  31  exerts on the ring  30  an effort E 2  directed towards the pipe C 1  as shown in FIGS. 7 and 8. The needles  10  and  11 , which are in abutment against the ring  30 , are pushed towards the opening of the bore and take a position of abutment against the flange  1   b  shown in FIG.  7 . In this position, the needles  10  and  11  exert on the sidewalls  53   c  and  53   d  of the ring  53  an effort substantially similar to effort E 2 , which has the effect of also pushing this ring  53  and the sleeve  60  which is fast therewith in the direction of pipe C 1 . The position of FIGS. 7 and 8 is then attained, in which the balls  40  and  41  are maintained in position in the groove  1   a , as shown in FIG.  8 . 
     In the positions of FIGS. 5 to  8 , the air located in the pipe C 1  may flow from the connector  1  into the volume V, which makes it possible to drain the pipe C 1  and subsequently to avoid any risk of whiplash when the male and female elements A and B are effectively separated. 
     From volume V, the air fills the internal interstices of the female element B and, in particular, an annular chamber C defined in the inner volume of the sleeve  60  around the body  2 . On the pipe C 1  side, the annular chamber C is obturated by the ring  53 . Due to the flow of the air under pressure from the volume V towards the chamber C, the pressure P in the annular chamber C tends to increase. 
     When it is desired to continue disconnection of the male and female elements A and B, it suffices to exert on the sleeve  60  an effort E 3  as shown in FIGS. 9 and 10, in the direction opposite the effort E 1 , which has the effect of displacing the ring  53  in the direction of the pipe C 1  beyond the opening of the central bore  2   a  of the body  2 . The bearing portions  53   a  and  53   b  then no longer oppose the extraction of the balls  40  and  41  outside the groove  1   a  of the connector  1 . When the balls  40  and  41  are extracted from the groove  1   a  and since the needles  10  and  11  are already upstream of the flange  1   b , there is nothing to oppose the extraction of the connector  1  from the body  2 , which may in that case be effected as shown in FIGS. 9 and 10. 
     During introduction of the male element A in the female element B, the inclined front face of the flange  1   b  pushes the balls  40  and  41  upstream. The balls, captive in their slots  50  and  51 , come into abutment in these slots and push the body  2  inside the sleeve  60  held in the operator&#39;s hand. The position of FIGS. 9 and 10 is then attained. In this position, the balls  40  and  41  may be driven radially to the outside of the slots  50  and  51  by the flange  1   b  of the connector  1  in the course of introduction in the bore  2   a  of the body  2 . In effect, the ring  53  and the ring  30  do not overlap at the level of parts  53   a ,  53   b , and  30   c . In this way, taking into account the operation of the needles  10  and  11  described with reference to FIGS. 1 to  3 , it will be understood that the connection between the male and female elements A and B is automatic, in that it intervenes solely by the movement of introduction of the male connector  1  in the body  2 . 
     Returning to the intermediate positions shown in FIGS. 5 to  8 , and corresponding to the discharge of the pipe C 1 , it will be understood that it is indispensable that the balls  40  and  41  perform their function of retention of the connector  1  inside the body  2  efficiently, until the pipe C 1  is completely discharged, in order to avoid any untimely separation of the male part A from the female part B. Such a separation would in effect be the same as denying the feature of double release of the connection in question. 
     Due to the increase in the pressure P in the chamber C, the effort E 4  exerted on the face  30   b  of the ring  30  in the direction of the pipe C 1  increases as the air coming from this pipe discharges. 
     If the pressure P in the chamber C becomes too high, care must be taken that the effort E 4  is not sufficient to push the ring  53  and the sleeve  60  towards the position of FIGS. 9 and 10 in which the balls  40  and  41  may be ejected from the groove  1   a , while the operator has not exerted on the sleeve  60  any effort equivalent to the effort E 3  represented in FIGS. 9 and 10. 
     In order to eliminate this danger of untimely opening of the connection, and in accordance with the invention, it is provided to limit the movement of the sleeve  60  and of the ring  53  in the direction of the pipe C 1  in the position of FIGS. 5 to  8 . 
     To that end, vents  100  are provided in the body  2 , so that the air flowing from the connector in the volume V may follow the path represented by arrow F′ in FIG.  7 . In this way, a potentially dangerous rise in pressure in chamber C is avoided. 
     According to an embodiment of the invention (not shown), it may also be provided that the inner surface of the ring  53  presents longitudinal ribs which define channels with the outer surface of the body  2 , these channels allowing communication of chamber C and the outside atmosphere. These channels therefore also constitute vents for communication of the inner volume of the sleeve  60  and the outside of the connection. 
     In any case, the total cross-section of the vents is provided to be sufficient to allow the flow of the fluid issuing from pipe C 1  without a substantial rise in the pressure P in the chamber C, with the result that any risk of untimely movement of the ring  53  may be set aside. 
     Furthermore, a safety ring  200  is housed in the chamber C, i.e. between the body  2  and the sleeve  60 , in abutment against a shoulder  2   b  of the body  2 . The ring  200  is more particularly visible in FIG.  4 . It comprises an annular portion  200   a  and two sectors  200   b  and  200   c  presenting, in combination with the annular portion  200   a , a cross-section in the form of a C as shown in FIGS. 3,  6 ,  8  and  10 . The face  200   d  of the ring  200  turned towards the pipe C 1  is in simple abutment against the spring  31 , so that the ring  200  is elastically loaded in the direction of the shoulder  2   b  of the body  2 . 
     Furthermore, the sleeve  60  bears a plurality of inner heels or tabs  60   a  of which two are visible in FIGS.  1 , 5 , 7  and  9  and which are provided to cooperate with the face  200   e  of the safety or stop ring  200  turned toward the pipe C 2 . 
     In the event of rise in pressure in the chamber C, the effort E 4 , exerted on the locking ring  30  and which would tend to displace the ring  53  in the direction of the pipe C 1 , would have the effect of likewise entraining the sleeve  60  which is fast with the ring  53 . Such a movement of the sleeve  60  in the direction of the pipe C 1  would involve, due to the abutment of the heels  60   a  on the face  200   e  of the ring  200 , a displacement of this ring against the effort E 5  generated by the spring  31  and the pressure prevailing in the chamber C. In other words, the antagonistic efforts E 4  and E 5  which are respectively exerted on the rings  53  and  200 , as shown in FIG. 8, are due to the pressure P and to the spring  31 , with the result that they are substantially of the same value, which makes it possible to avoid a lack of equilibrium which might lead to a displacement of the ring  53  and of the sleeve  60 . In this way, independently of the value of the pressure P, a situation of stable equilibrium in the configuration of FIGS. 5 and 8 is obtained. The air present in the pipe C 1  can therefore escape safely, through the vents  100  or equivalent, without risk of auto-movement of the sleeve  60 . 
     In order to improve the reliability of the connection further, the clearance J between the sleeve  60  and the body  2  downstream of the ring  200  is provided to be greater than the clearance j between the ring  200  and the body  2  and than the clearance j′ between the ring  200  and the sleeve  60 . The air present in the chamber C may thus flow in the annular space defined by the clearance J, as represented by arrow F″ in FIGS. 7 and 8. 
     Thus, the pressure prevailing downstream of the safety ring  200  is permanently lower than the pressure P prevailing in the chamber C, as long as this pressure is different from atmospheric pressure. This make it possible to make full use of the force due to the pressure P prevailing in the chamber C to load the ring  200  in the direction of the shoulder  2   b , without risk of unstable positioning of the ring  200  inside the chamber C, even in a variant embodiment where the spring  31  does not cooperate with the ring  200 . 
     The vents  100 , on the one hand, and the safety ring  200 , on the other hand, may be provided independently in the connection of the invention or in combination, as shown in the Figures. In other words, the ring  200  might be omitted as long as sufficient vents are provided; similarly, the vents might be eliminated while only one safety ring is provided. The safety ring presents the additional advantage of not being accessible from the outside, with the result that its functioning is never altered. In particular, when the connection operates in a dirty environment, it may be that waste encumbers the vents  100  and even blocks them, which would render them inefficient. The ring  200  functions totally satisfactorily, including in a dirty environment. 
     It should also be noted that the ring  200  is efficient whatever the pressure P which depends on the pressure of the fluid transiting in the connection, since the effort exerted on the ring  200  to withstand the displacement of the sleeve  60  increases with this pressure. 
     In fact, the ring  200  constitutes an element for stopping displacement of the sleeve  60  and the ring  5 . In the example shown, it is constituted by a ring, but it is obvious that it might also be formed by discrete elements distributed around the body  2  in the inner volume of the sleeve  60 . 
     The invention has been shown with a locking means formed by needles and retention members formed by ball, which allows the female element B to be adapted to the connectors  1  of the male element A of variable geometry. However, other locking means and retention members may be envisaged, in particular claws, possibly mounted on an annular ring. Such claws may, as desired, replace the needles, the balls or both at the same time. The invention is also applicable with retention members formed by articulated levers in the female part and each provided with a nose or beak adapted to penetrate in an outer peripheral groove of the male connector. The geometry of the nose or beak of these levers may be adapted to that of the groove of the connector, hence a considerable adaptability of the female element with respect to the different types of connectors on the market. 
     The invention has been described with a connection supplied with air. However, it is applicable whatever the fluid, gaseous or liquid, transiting in the pipes.