COUPLING DEVICE FOR ONE PIPE

Description

DOMAINE DE L'INVENTION

[0001] The present invention relates to the field of fluid connection devices implemented in fluid circulation and / or distribution systems.

[0002] More particularly, the present invention relates to a device for connecting a tube and provided with means for checking the correct connection status of the tube to the connection device. In particular, the present invention proposes a device for connecting a tube and provided with a haptic indicator of correct connection. ARRIERE PLAN TECHNOLOGIQUE DE L'INVENTION

[0003] Fluid connection devices are now widely used in motor vehicles and road transport vehicles. These fluid connection devices are used in particular to ensure the circulation and / or distribution of a fluid within these vehicles.

[0004] Furthermore, in order to ensure assembly rates compatible with the requirements of the automotive and / or road transport vehicle industries, it may be required to have fluid connection devices allowing rapid connections and means of verifying their assembly.

[0005] In this regard, document [1] cited at the end of the description discloses a connection device allowing the fluid connection of a tube or a conduit, and which includes a visual assembly indicator.

[0006] In particular, this connection device comprises a substantially cylindrical hollow body having a receiving housing opening onto an insertion opening. A fastening ring and a sealing gasket are also arranged in the receiving housing and arranged to secure a tube inserted into the receiving housing through the insertion opening and in an insertion direction.

[0007] The connecting device also comprises a cartridge capable of being locked in either of a first or a second position in the receiving housing. The cartridge initially locked in the first position partially protrudes from the receiving housing through the insertion opening. Inserting a predetermined length into the receiving housing, depending on the direction of insertion, allows the cartridge to be unlocked and to slide from the first position to the second position in which said cartridge is fully integrated into the receiving housing.

[0008] The complete insertion of the cartridge into the receiving housing allows to conclude the correct connection of the tube with the connection device. However, there are situations in which the lighting conditions and / or the cramped connection areas on the vehicles prevent the observation of the position of the cartridge and thus make the visual indicator function of said cartridge ineffective.

[0009] Alternatively, it may have been envisaged to provide the connection device with an audible indicator. Document [2] cited at the end of the description discloses an example. In particular, the connection device described in this document comprises an audible indicator formed by an elastic pin configured to jump as soon as a predetermined length of the tube is pushed into the connection device. However, a noisy environment makes sound detection difficult.

[0010] Still alternatively, document [3] cited at the end of the description discloses a connection device which includes a haptic indicator of correct tube assembly. The connection device described in this document is provided, in an inner channel, with a stop against which the tube exerts a force until the stop breaks, indicating that the tube has been correctly inserted. However, the breakage of the stop prevents any subsequent verification of the correct assembly of the tube in the inner channel.

[0011] Document [4] cited at the end of the description discloses a plug-in type tube joint which can be connected to a connecting tube by simply inserting the connecting tube into a main body.

[0012] An aim of the present invention is therefore to propose a connection device configured to allow the correct connection of a tube in noisy, dark and / or cramped environments.

[0013] Another aim of the present invention is to propose a connection device provided with a tube correct assembly indicator capable of being activated as many times as necessary. BREVE DESCRIPTION DE L'INVENTION

[0014] The present invention relates to a device for connecting a tube, according to claim 1.

[0015] The device includes: a hollow body defining a housing which comprises an opening through which a tube is intended to be inserted by sliding in a direction of insertion; a fastening ring arranged in the housing coaxially with the direction of insertion and intended to be engaged with a tube inserted in the housing; a first stop arranged in the housing and upstream of the fastening ring in the direction of insertion, and against which said ring is capable of abutting;a cartridge against which the tube, inserted of a predetermined length and engaged with the attachment ring, is intended to abut in order to impose on said cartridge a state of connection, the cartridge in the state of connection being capable of sliding between a first and a second position in order to accompany the sliding of the tube in engagement with the attachment ring, the passage of the cartridge from the second to the first position requiring the tube to slide in an extraction direction, opposite to the insertion direction, in order to abut the attachment ring against the first stop, while the passage of the cartridge from the first to the second position allows sliding of the tube in the insertion direction in order to put the attachment ring at a distance from the first stop; a spring exerting a force against the cartridge in the extraction direction in order to impose on the cartridge, in the state of connection, to adopt its first position. ;

[0016] The housing is delimited by an internal surface of the hollow body, and which presents a symmetry of revolution around a main axis parallel to the direction of insertion.

[0017] The cartridge comprises a sleeve which extends from a free end in the direction of insertion, and which is intended to ensure the guidance of the tube when the latter is inserted into the housing.

[0018] The is capable of being maintained, by at least one locking means of the connection device, in a state, called the locked state, and in which any sliding of the cartridge towards the second position is prohibited, the passage from the locked state to the connection state being induced by the insertion, according to the direction of insertion, of a length of tube equal to the predetermined length.

[0019] According to one embodiment, the locking means comprises a second stop and a flexible lever, the second stop being formed on the internal surface, while the flexible lever, carried by the sleeve, extends in a divergent manner relative to the sleeve and comprises an end, called the locking end, intended to abut against the second stop when the cartridge is in the locked state, the flexible lever is furthermore configured to flex in a convergent manner internally to the sleeve when the tube is inserted in order to position the locking end set back from the second stop.

[0020] According to one embodiment, the sleeve comprises an end stop, opposite its free end, against which the tube is intended to stop as soon as it is inserted into the housing of a length at least equal to the predetermined length.

[0021] According to one embodiment, the cartridge comprises a jacket mechanically secured to the sleeve by one end of said sleeve opposite the free end, the jacket comprising a collar against which the spring exerts its force on said cartridge.

[0022] According to one embodiment, the cartridge comprises a lug which, when said cartridge is in the locked state, is located in a slot of the attachment ring in order to impose a constraint on it resulting in a spacing greater than a spacing in the free state of said attachment ring.

[0023] According to one embodiment, a dust cover ring is arranged in the opening, and upstream of the first stop in the direction of insertion, advantageously the dust cover ring is engaged with the hollow body by snap-fastening.

[0024] According to one embodiment, an O-ring is arranged in the housing upstream of the first stop in the direction of insertion, the dust cover ring covering said O-ring.

[0025] According to one embodiment, the first stop forms a ring at least partially embedded in the dust cover ring.

[0026] According to one embodiment, another O-ring is also arranged downstream of the attachment ring depending on the direction of insertion.

[0027] According to one method of implementation, the internal surface of the hollow body comprises a stop shoulder against which the spring bears. Brève description des dessins

[0028] Other characteristics and advantages of the invention will emerge from the detailed description which follows with reference to the appended figures in which: [ Fig.1 ] There [ Fig.1 ] is a schematic representation of a connection device according to an exemplary embodiment of the present invention, in particular, the [ Fig.1 ] represents the connection device according to a section plane passing through the main axis AA' of said connection device; [ Fig.2 ] There [ Fig.2 ] is a schematic representation of the hollow body implemented in the example of the [ Fig.1 ] and according to a perspective view allowing the opening through which the tube is intended to be inserted to be observed; [ Fig.3 ] There [ Fig.3 ] is an illustration of the connecting device of the [ Fig.1 ] according to the section plane passing through the main axis AA', and in which a length of tube, less than the predetermined length, is inserted into the housing through the opening and according to the direction of insertion; [ Fig.4 ] There [ Fig.4 ] is an illustration of the connecting device of the [ Fig.1 ] according to the section plane passing through the main axis AA', and in which a length of tube, equal to the predetermined length, is inserted into the housing through the opening and according to the direction of insertion, the cartridge, in its connected state, adopting its first position; [ Fig.5 ] There [ Fig.5 ] is an illustration of the connecting device of the [ Fig.1 ] according to the section plane passing through the main axis AA', and in which a length of tube, equal to the predetermined length, is inserted into the housing through the opening and according to the direction of insertion, the cartridge, in its connected state, adopting its second position; [ Fig.6 ] There [ Fig.6 ] is a schematic representation of a cartridge according to a section plane passing through the main axis AA' and capable of being implemented in the connection device according to the present invention; [ Fig.7 ] There [ Fig.7 ] is a schematic perspective representation of a cartridge comprising a lug imposing a spacing on the attachment ring; [ Fig.8 ] There [ Fig.8 ] is a schematic representation of a connection device according to another exemplary embodiment which is not covered by the text of the claims, in particular, the [ Fig.8 ] represents the connection device according to a section plane passing through the main axis AA' of said connection device; [ Fig.9 ] There [ Fig.9 ] is a schematic representation of a cartridge according to a section plane passing through the main axis AA' of the connection device according to the other exemplary embodiment; [ Fig.10 ] There [ Fig.10 ] is a schematic representation of a connection device according to the other embodiment, in particular, the [ Fig.10 ] represents the connection device according to a section plane passing through the main axis AA' of said connection device and in the connected state. DESCRIPTION DETAILLEE DE L'INVENTION

[0029] The present invention relates to a connection device intended to ensure a fluidic connection, and advantageously a sealed one, between a tube or a conduit and a female element (not shown in the figures). This connection can in particular be implemented in a fluid flow and / or distribution system (for example a liquid such as water or oil, or a gas, or air) in the automotive field, in particular in cars or any other type of commercial vehicle such as a coach, a truck, a trailer. The invention is however not limited to these fields alone, and can also be implemented in the railway and / or aeronautical fields.

[0030] To the [ Fig.1 ], we can see a connection device 1 according to an exemplary embodiment of the present invention. The principles set out below are not limited to the sole arrangement illustrated in this example. In particular, those skilled in the art, on the basis of the following, will be able to envisage other configurations. In particular, the connection device 1 according to this exemplary embodiment is represented along a section plane passing through an axis, called the main axis AA' of said connection device 1.

[0031] In particular, the connection device 1 comprises a hollow body 2 which has a housing 3 opening through an opening 4 ([ Fig.2 ]). The opening 4 allows in particular the insertion of a tube in an insertion direction u carried by the direction defined by the main axis AA'. The housing 3 is delimited by an internal surface 5 of the hollow body 2 and which has a symmetry of revolution around the main axis AA'.

[0032] The outer surface of the hollow body 2 may comprise one or more circumferential grooves R1, R2 intended to accommodate one or more O-rings J1, J2 making it possible to ensure a sealed junction with a female element.

[0033] The connecting device 1 comprises a hooking ring 6 and a first stop 7 for securing a tube capable of being inserted into the housing in the insertion direction u. More particularly, the hooking ring 6 and the first stop 7 are arranged to prevent the extraction of the tube as soon as the latter is inserted into the housing 3 and is engaged with said hooking ring 6.

[0034] In this regard, the attachment ring 6 may be provided with attachment means enabling it to be engaged with the tube. More particularly, the attachment ring 6 may have a tapered inner section 8 enabling it to scratch the outer surface of the tube, and thus be engaged with the latter.

[0035] By "engaged" is meant two elements mechanically secured to each other. The expression "engaged" also has a reciprocal nature so that a first element engaged with a second element implies that the second element is engaged with the first element. Thus, and throughout the description, as soon as the attachment ring is engaged with the tube implies that the tube is engaged with the attachment ring.

[0036] The first stop 7, for its part, is arranged upstream of the attachment ring 6 in the direction of insertion u so as to constitute an obstacle against which the attachment ring 6 is likely to abut. In a particularly advantageous manner, the first stop 7 can be formed by a ring whose axis of revolution coincides with the main axis AA', and is located in a fixed connection in the housing 3 of the hollow body 2.

[0037] Thus, an extraction force, in an extraction direction v (opposite to the insertion direction u), on a tube with which the attachment ring 6 is engaged, will position the latter in abutment against the first stop 7 and thus prevent the tube from being withdrawn.

[0038] Still advantageously, the first stop 7 may also comprise an internal surface 9, opposite its peripheral surface 10, having a divergent frustoconical shape in the direction of insertion u. This latter aspect makes it possible to constrain the attachment ring 6 against the tube when an extraction force is applied. In a complementary manner, the attachment ring 6 may comprise a peripheral surface 11 which also has a divergent frustoconical shape in the direction of insertion u. This aspect has the effect of reinforcing the constraint effect imposed by the first stop 7 on the attachment ring 6 as soon as an extraction force is exerted on a tube engaged with said attachment ring 6.

[0039] By "truncated cone surface diverging in the direction of insertion u" we mean a shape which widens in the direction of insertion u.

[0040] The connecting device 1 according to the present invention also comprises a cartridge 12.

[0041] In particular, the cartridge 12 is arranged in the housing 3 and is capable of adopting a state called the connection state. The connection state is in particular imposed on the cartridge 12 as soon as a predetermined length D of tube is inserted into the housing 3 in the insertion direction u, and is located by one of its ends, called the insertion end E, in abutment against the cartridge 12.

[0042] The cartridge 12 comprises a sleeve 13 which extends from a free end 12a in the direction of insertion u.

[0043] There [ Fig.3 ] is an illustration of the connection device 1 and in which a length of tube T less than the predetermined length is inserted into the housing through the opening 5 and according to the direction of insertion. In this [ Fig.3 ], the hooking ring 7 is engaged with the tube T. In other words, the insertion end E of the tube T is downstream of the hooking ring 6 in the insertion direction u. However, to the extent that the inserted length of tube T remains less than the predetermined length D, said tube T is not in abutment against the cartridge 12.

[0044] There [ Fig.4 ], illustrates a later stage of insertion of the tube T into the housing 3 according to the direction of insertion. In particular, the [ Fig.4 ] is an illustration of the connecting device 1 of the [ Fig.3 ] and in which the predetermined length D of the tube T is inserted into the housing 3 in the insertion direction u. at this stage of insertion, the tube T is in abutment by its insertion end against the cartridge 12 and is engaged with the attachment ring 6.

[0045] According to the present invention, the cartridge 12, in its connected state, is capable of sliding in either the insertion direction or the extraction direction, between a first position and a second position in order to accompany the sliding of the tube engaged with the attachment ring 6. By "accompanying the sliding", we mean an overall movement in the same direction of the tube, the attachment ring and the cartridge 12.

[0046] In other words, the sliding of the cartridge 12 in either the insertion direction u or the extraction direction v over a given distance can be accompanied by the same movement of the tube T and the attachment ring 6.

[0047] In this respect, the first position is a position upstream of the second position in the direction of insertion u, and for which the attachment ring 6 is in abutment against the first stop 7 (this aspect is notably illustrated in [ Fig.4 ]).

[0048] As illustrated in [ Fig.5 ], the cartridge 12, as soon as it is in the connected state, can slide, in the direction of insertion u, from the first position to the second position. This sliding from the first position to the second position can for example be induced by a force exerted by the tube T, in the direction of insertion u, in abutment against the cartridge 12. In other words, the sliding of the cartridge 12, from the first to the second position, is accompanied by an overall movement of the tube, the attachment ring and the cartridge. Furthermore, this overall movement positions the attachment ring 6 at a distance from the first stop 7.

[0049] The connection device 1 according to the present invention further comprises a spring 14 arranged to exert a force against the cartridge 12 in the extraction direction v in order to force said cartridge 12, in the connection state, to adopt its first position.

[0050] In other words, the spring 14, as arranged, makes it possible to make the movement of the tube T, the attachment ring 6 and the cartridge 12 integral. In particular, by default, the cartridge 12 is in its first position under the effect of the force exerted by the spring 14 and therefore requires the attachment ring 6 to be in abutment against the first stop 7. Conversely, a force exerted on the tube T in the direction of insertion u causes the tube T, the attachment ring 6 and the cartridge 12 to slide together. A release of this force will restore the cartridge 12 to its first position and will thus position the attachment ring 6 in abutment against the first stop 7.

[0051] Thus, as soon as the cartridge 12 is in the connection state, the assembly formed by the tube T, the attachment ring 6 and the cartridge 12 can be subjected to back and forth movements in the direction defined by the main axis AA'. In other words, an operator wishing to check the correct connection of the tube T to the connection device 1 can exert a force in the insertion direction u on the tube T in order to slide the cartridge from its first position to its second position. A release of this force will restore the cartridge 12 to its first position under the effect of the spring 14. This sequence will reveal on the one hand an insertion of the predetermined length D of the tube T into the connection device and, on the other hand, the gripping effect with the attachment ring.

[0052] This operation, carried out manually, can be performed in confined, unlit and / or noisy places, thus allowing the correct connection of the tube in the connection device to be checked efficiently and unambiguously.

[0053] The connecting device 1 comprises a locking means. In particular, the locking means may be arranged to maintain the cartridge 12 in a state, called the locked state, in which any sliding of said cartridge 12 towards the second position is prohibited. More particularly, the locking means may be arranged to cooperate with the tube T in order to allow the cartridge 12 to pass from the locked state to the connection state.

[0054] In particular, the transition of the cartridge 12 from the locked state to the connected state can be induced by the insertion of a length of tube T equal to the predetermined length.

[0055] Thus, and as illustrated in the [ Fig.3 ], the locking means comprises a second stop 15 and a flexible lever 16. More particularly, the second stop 15 is formed on the internal surface 5, while the flexible lever 16, carried by the sleeve 13, extends in a divergent manner relative to the sleeve 13 and comprises an end, called the locking end 17, intended to abut against the second stop when the cartridge 12 is in the locked state.

[0056] The flexible lever 16 is further configured to flex convergently internally to the sleeve 13 during insertion of the tube T in order to position the locking end set back from the second stop 15. In particular, the connection device 1 is arranged so that the flexing of the flexible lever 16 only occurs when a length of tube T equal to the predetermined length is inserted into the housing.

[0057] In this regard, and as illustrated in [ Fig.3 ], the length of tube T inserted into the housing is less than the predetermined length, so that said tube T does not exert any force on the flexible lever 16. In this figure, the flexible lever 16 remains in abutment against the second stop 15 and imposes on the cartridge 12 its locked state.

[0058] To the [ Fig.4 ], the length of tube T inserted into the housing is equal to the predetermined length so that said tube exerts a force on the flexible lever 16 so as to flex the latter in order to place the locking end 17 back from the second stop 15. The flexion of the flexible lever 16 thus makes it possible to impose on the cartridge 12 its connection state.

[0059] Advantageously, the sleeve 13 comprises an end stop 18, opposite its free end 12a, against which the tube T is intended to abut as soon as it is inserted into the housing of a length at least equal to the predetermined length.

[0060] Still according to this particular embodiment, the cartridge 12 (also illustrated in [ Fig.6 ]) comprises a jacket 19 mechanically secured to the sleeve by one end of said sleeve opposite the free end 12a, and which further comprises a collar 20 against which the spring 14 exerts its force on said cartridge 12. More particularly, the jacket 19 is arranged externally and coaxially with the sleeve 13. It is understood that the jacket 19 has a tube shape which extends, according to the direction of insertion, between a first end 19a and a second end 19b, the collar being arranged on the first end 19a ( [ Fig.4 ]).

[0061] According to this exemplary embodiment, the spring 14 is in compression between the collar 20 and a support shoulder 26 formed on the internal surface of the hollow body 2.

[0062] The cartridge 12 may also comprise a lug 21 which, when said cartridge 12 is in the locked state, is located in a slot of the attachment ring in order to impose a constraint on it resulting in a spacing greater than a spacing in the free state of said attachment ring 6 ([ Fig.7 ]).

[0063] Advantageously, a seal 22 can be inserted between the attachment ring 6 and the collar 20 in order to ensure a tight connection between the tube and the connection device. The seal 22 can also provide a stop function against which the attachment ring 6 abuts in the insertion direction as long as the cartridge is not in its connection state (it is understood, but not necessary to specify, that the seal 22 abuts against the collar of the cartridge). This aspect is illustrated in particular in [ Fig.1 ], to the [ Fig.3 ] and to the [ Fig.4 ]. In particular, as illustrated in [ Fig.1 ] and to the [ Fig.3 ], the cartridge 12 is in the locked state. When it is inserted through the opening, the tube T passes (by force) through the attachment ring without causing the latter to slide as long as it is not in abutment against the end stop 18 of the cartridge 12. At the [ Fig.4 ], the cartridge 12 is in the connected state and therefore allows an overall movement according to the direction of insertion of the tube, of the attachment ring engaged with the tube, and of the cartridge.

[0064] The connection device may also comprise a dust cover ring 23 placed on or in the opening 4 and in which a light is formed allowing the insertion of the tube T into the housing 3.

[0065] According to this particular embodiment, and as illustrated in [ Fig.5 ], the dust cover ring 23 is arranged upstream of the first stop in the direction of insertion. More particularly, the dust cover ring 23 is engaged with the hollow body 2 by snap-fastening.

[0066] Still advantageously, another O-ring 27 is arranged in the housing 3 upstream of the first stop 7 in the direction of insertion u.

[0067] The first stop 7 may comprise a ring at least partially embedded in the dust cover ring 23.

[0068] There [ Fig.8 ] is a schematic representation of a connection device 1 according to another embodiment. In particular, this other embodiment essentially incorporates the elements described previously but does not, however, include a locking means in accordance with the embodiment described previously.

[0069] More particularly, according to this other embodiment, the attachment ring 6 and the cartridge 12 are arranged to adopt a state, called the engagement state, in which the attachment ring 6, which is split, is imposed, by the cartridge 12, a constrained state resulting in a spacing, called the second spacing, greater than its spacing in the free state, called the first spacing.

[0070] The cartridge 12 and the attachment ring 6 are arranged so that the transition from the engagement state to the connection state of the cartridge 12 is induced by the insertion of the predetermined length D of tube T so as to slide the cartridge 12 in the direction of insertion and put the attachment ring 6 into engagement with the tube T.

[0071] In this regard, the cartridge 12 may comprise a collar 24 formed around the sleeve 13, while the attachment ring 6 comprises, in the insertion direction u, a first section 6a and a second section 6b ([ Fig.9 ]).

[0072] It is understood that the collar 24 takes the form of a ring formed around the sleeve 13.

[0073] The first section 6a carries the tapered inner section 8 allowing the outer surface of the tube to be scratched, and thus to be engaged with the latter.

[0074] The second section 6b, which extends over a length L, is intended to cooperate with the collar to impose the second spacing when the cartridge is in the engaged state.

[0075] Thus, as illustrated in [ Fig.8 ] and to the [ Fig.9 ], as soon as the cartridge 12 is in the engaged state, the collar 24 is inserted by sliding into the second section 6b of the attachment ring 6 in order to impose the second spacing on the latter.

[0076] The internal surface 5 of the hollow body comprises, in the insertion direction u, a first part of a first diameter and a second part of a second diameter, smaller than the first diameter, so as to form an engagement shoulder 25 and against which the second section 6b is intended to abut during the transition from the engagement state to the connection state of the cartridge, in order to release the attachment ring.

[0077] Thus, when it is inserted in the insertion direction u, the tube T exerts a force against the collar 24 leading to a sliding of the cartridge 12. This sliding, insofar as the attachment ring 6 is in abutment against the engagement stop 25, results in a disengagement of the collar 24 from the second section 6b of the engagement ring 6. More particularly, the complete disengagement of the collar 24 in the second section 6b is effective after sliding of the cartridge over a length L ([ Fig.10 ]).

[0078] As soon as the disengagement of the collar 24 from the second section 6b is complete, the attachment ring 6 is no longer constrained by said collar and is thus engaged with the tube T. In other words, the cartridge 12 is in the connected state.

[0079] According to this other embodiment, the spring 14 exerts its force against the collar 24. More particularly, the spring 14 is in compression between the collar 24 and the support shoulder 26 formed on the internal surface of the hollow body 2.

[0080] Still according to this other example, the dust cover ring 23 is engaged by external snap-fastening to the hollow body 2. In other words, the dust cover ring 23 covers the opening of the housing.

[0081] Furthermore, the seal 22 and the other seal 27 are arranged upstream of the first stop. In this regard, the seal 22 and the other seal 27 may be separated by a ring, called a separation ring 28.

[0082] Regardless of the example considered, the connection device 1 allows verification of the correct connection of a tube in cramped and dark environments. Furthermore, this verification can be carried out repeatedly and as many times as necessary without affecting the quality of the connection.

[0083] Furthermore, the connecting device 1 may be adapted to compensate for the bevel effect resulting from a non-straight (non-orthogonal) cut of the tube end. In other words, the connected state of the cartridge may only occur when a given length of the tube has actually passed through the attachment ring.

[0084] Of course, the invention is not limited to the embodiments described and variant embodiments can be made without departing from the scope of the invention as defined by the claims. Références

[0085] [1] WO2021148737A1 ; [2] FR3021089A1 ; [3] EP2249072A1 ; [4] JPH0735281A.

Claims

1. A device (1) for coupling a tube, comprising: - a hollow body (2) defining a housing (3) which comprises an opening (4) through which a tube is intended to be inserted by sliding according to a direction of insertion, the housing (3) is delimited by an inner surface (5) of the hollow body (2), and which has a rotational symmetry about a main axis parallel to the direction of insertion; - a locking ring (6) arranged in the housing (3) coaxially to the direction of insertion and intended to be engaged with a tube inserted into the housing (3); - a first stop (7) arranged in the housing (3) and upstream of the locking ring (6) according to the direction of insertion, and against which said ring is able to abut; - a cartridge (12) against which the tube, inserted by a predetermined length and engaged with the locking ring (6), is intended to abut in order to impose a connection state on said cartridge (12), the cartridge (12) in the connection state being able to slide between first and second positions in order to accompany the sliding of the tube engaged with the locking ring (6), the passage of the cartridge (12) from the second to the first position imposing on the tube to slide according to a direction of extraction, opposite to the direction of insertion, in order to stop the locking ring (6) against the first stop (7), whereas the passage of the cartridge (12) from the first to the second position enables a sliding of the tube according to the direction of insertion in order to place the locking ring (6) at a distance from the first stop (7), the cartridge (12) comprising a sleeve (13) which extends from a free end (12a) in the direction of insertion, and which is intended to ensure the guidance of the tube during the insertion of the latter into the housing (3), the coupling device (1) comprising at least one locking means, the cartridge (12) being able to be held, by the locking means, in a so-called locked state, and wherein any sliding of the cartridge (12) towards the second position is prohibited, the passage from the locked state towards the connection state being induced by the insertion, according to the direction of insertion, of a tube length equal to the predetermined length; - a spring (14) exerting a force against the cartridge (12) according to the direction of extraction in order to impose on the cartridge (12), in the connection state, to adopt its first position.

2. The coupling device (1) according to claim 1, wherein the locking means comprises a second stop (15) and a flexible lever (16), the second stop (15) being formed on the inner surface (5), whereas the flexible lever (16), carried by the sleeve (13), extends divergently with respect to the sleeve (13) and comprises an end, so-called the blocking end (17), intended to abut against the second stop (15) when the cartridge (12) is in the locked state, the flexible lever (16) is further configured to bend convergently inside the sleeve (13) during the insertion of the tube in order to position the blocking end (17) set back from the second stop (15).

3. The coupling device (1) according to claim 2, wherein the sleeve (13) comprises an end stop (18), opposite to its free end (12a), against which the tube is intended to abut as soon as it is inserted into the housing (3) by a length at least equal to the predetermined length.

4. The coupling device (1) according to one of claims 1 to 3, wherein the cartridge (12) comprises a liner (19) mechanically secured to the sleeve (13) by one end of said sleeve (13) opposite to the free end (12a), the liner (19) comprising a collar (20) against which the spring (14) exerts its force on said cartridge (12).

5. The coupling device (1) according to one of claims 1 to 4, wherein the cartridge (12) comprises a lug which, when said cartridge (12) is in the locked state, is in a slot of the locking ring (6) in order to impose a stress thereon resulting in a gap larger than a gap in the free state of said locking ring (6).

6. The coupling device (1) according to one of claims 1 to 5, wherein a dust cap ring (23) is arranged in the opening (4), and upstream of the first stop (7) according to the direction of insertion, advantageously the dust cap ring (23) is engaged with the hollow body (2) by snap-fitting.

7. The coupling device (1) according to claim 6, wherein an O-ring gasket is arranged in the housing (3) upstream of the first stop (7) according to the direction of insertion.

8. The coupling device (1) according to claim 6 or 7, wherein the first stop (7) forms a ring at least partially fitted into the dust cap ring (23).

9. The coupling device (1) according to one of claims 1 to 8, wherein another O-ring gasket is also arranged downstream of the locking ring (6) according to the direction of insertion.

10. The coupling device (1) according to any one of claims 1 to 9, wherein the inner surface (5) of the hollow body (2) comprises a stop shoulder against which the spring (14) bears.