Clamping coupling element and a coupling including such an element

A female coupling element for releasably joining pipes and which receives a male element along a longitudinal axis thereof, and which includes a body, a locking ring secured in translation relative to the body and provided with at least one slot for receiving at least one radially projecting portion of the male element, and at least one locking notch for receiving the projecting portion in a configuration in which the projecting portion is locked axially along the longitudinal axis, a safety ring superposed, at least in part, on the locking ring, and the safety ring including at least one elastic member that is deformable between a first configuration in which the member prevents the projecting portion of the male element moving out of a locking notch and a second configuration in which the member allows the projecting portion to move from the locking notch.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a coupling element and to a coupling for releasably joining together two pipes.

2. Brief Description of the Related Art

FR-A-2 901 595 discloses a female coupling element for receiving a male coupling element. The female element comprises a body, a locking ring mounted about the body, and a safety ring superposed on the locking ring. The movement of projecting locking studs placed on the male element is limited by the safety ring, which is urged to the front of the body by a spring. A function of locking these two elements together is thus obtained in reliable manner.

Nevertheless, in order to provide the safety function, it is necessary to cause a plurality of parts to co-operate. In addition to a solid steel safety ring, that type of coupling element also requires a spring and at least one lug serving to prevent the safety ring from turning.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a coupling element that includes means for providing locking on mutual engagement and means for making the locking safe, which means can be provided in simple manner.

To this end, the invention provides a female coupling element suitable for releasably joining pipes, said element being suitable for receiving a male element along a longitudinal axis of the element, the element comprising:a body;a locking ring secured in translation relative to the body and provided with at least one slot suitable for receiving at least one radially-projecting portion of the male element, and at least one locking notch suitable for receiving the projecting portion in a configuration in which said portion is locked axially along the longitudinal axis; anda safety ring superposed at least in part on the locking ring;

the female element being characterized in that the safety ring includes at least one elastically deformable member that is deformable between a first configuration in which the member prevents a projecting portion of the male element passing out of a locking notch, and a second configuration in which the member allows the portion to pass.

By means of the element of the invention, the two coupling elements can be locked to each other reliably, with locking in the connected position taking place automatically and in simplified manner, because of the presence of the elastically-deformable member of the safety ring. This provides a simplified construction for the coupling that is due to the spring and the anti-rotation lugs that are present in the prior art coupling being omitted.

According to other advantageous characteristics of the coupling element in accordance with the invention, taken in isolation or in any technically feasible combination:the member is elastically deformable between the first configuration and the second configuration by radial deformation;the safety ring is mounted to slide around the locking ring, and the locking ring is provided with an outer bearing surface suitable for coming into contact with at least one first inner surface of the or each elastically deformable member while said member is passing between the first configuration and the second configuration, and vice versa, the outer bearing surface or the first inner surface being inclined towards a receiver mouth of the coupling element at an angle of inclination relative to the longitudinal axis lying in the range 30° to 60°, and preferably in the range 40° to 50°;the body or the locking ring is provided with an abutment against which the safety ring comes to bear in the second configuration of the elastically-deformable member, the outer bearing surface being in contact with the first inner surface when the safety ring is in contact with the abutment;the inner surface of the or each elastically-deformable member suitable for coming into contact with at least one of the radially-projecting portions while it is being inserted into the slot for connection, forms a ramp that is inclined in the opposite direction to the receiver mouth of the coupling element, the angle of inclination of the inner surface of the or each member relative to the longitudinal axis lying in the range 30° to 60°, and preferably in the range 40° to 50°;the or each elastically-deformable member has an end that is received at least in part in the adjacent slot when the member is in the first configuration;when the or each elastically-deformable member is in the first configuration, a maximum radius defined between the longitudinal axis and a radially-outer surface of the end of the or each elastically-deformable member is less than or equal to a maximum radius defined between the longitudinal axis and a radially-outer surface of the locking ring in register with the slot;the locking ring has two guide surfaces for laterally guiding the elastically-deformable member;the guide surface situated at the side of the slot opposite from the locking notch is inclined relative to a radial direction;the guide surfaces are formed in register with a groove extending axially from a mouth of the slot;the locking ring is mounted so as to be capable of turning around the body; andthe safety ring is made of a synthetic material.

The invention also provides a coupling for releasably joining pipes, the coupling comprising a first coupling element and a second coupling element, the two coupling elements being suitable for engaging one within the other along a longitudinal coupling axis, one of the two elements being as described above.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 11show a bayonet coupling1comprising a male element2and a female element4. Each of these two elements2and4is adapted for releasably joining two pipes. For this purpose, each of these two elements2and4has a rear portion in fluid flow connection with a respective pipe C1or C2shown in chain-dotted lines and only inFIG. 1in order to clarify the drawings. The elements2and4are generally tubular and mutually complementary, such that they can be engaged one in the other along a longitudinal axis X-X that is common to these two elements.

The male element2comprises a generally tubular body6of circular section, and including three locking studs8, each projecting radially outwards from the body6. The three locking studs are regularly distributed around the periphery of the body6. These studs are of cylindrical shape and they thus extend in radial directions D8, forming between one another angles α of 120°, as shown inFIG. 2.

A valve member7is mounted in the body6and is resiliently biased by a spring9towards a seat61formed by the body6close to its front end62. Furthermore, an O-ring11provides sealing between the valve member7and the body6when the valve member presses against the seat61.

The female element4comprises a generally tubular body12of circular section having two circular section rings mounted thereabout, which rings overlap coaxially, i.e. an inner locking ring14and an outer safety ring16, both centered on the axis X-X. The locking ring14is axially secured to the body12. The safety ring16is placed in part around the locking ring14.

The body12of the female element4defines an inner shoulder18against which a spring20bears to exert a resilient force on a valve member22so as to press it against a seat24that is formed in the body12. The element4also has a pusher26that is stationary relative to the body12and that is in the form of an elongate rod centered on the axis X-X. When it bears against its seat24, the valve member22lies radially between the pusher26and the body12. Two O-rings28and30mounted respectively in the body12and on the pusher26then provide sealing when the element4is closed.

The locking and safety rings14and16of the female element4are suitable for turning together relative to the body12about the axis X-X.

The locking ring14has three grooves141that are regularly distributed about the axis X-X in such a manner as to be capable of simultaneously receiving the three locking studs8of the male element2. Each slot141is open to the front of the locking ring14, i.e. in its front face142that faces towards the element2in the configuration ofFIG. 1. Each slot141extends over the entire radial thickness of the locking ring14from a mouth143formed in the face142, with a curved shape that can be seen inFIG. 11. At its end opposite from the mouth143, each slot141terminates in a locking notch145. The locking ring14includes an abutment140limiting sliding of the safety ring16towards the front face142relative to the locking ring.

Each slot141is extended in a direction D144parallel to the axis X-X away from the mouth143by an axial groove144that is formed in a fraction only of the radial thickness of the locking ring14, in the outside thereof. The locking notch145is laterally offset relative to the groove144and to the mouth143.

The safety ring16has three elastically-deformable members or catches161. Each member161is designed to be received in part in a groove144and in a slot141of the locking ring14in connected and disconnected configurations of the coupling.

Each member161has a bulky free end162for obstructing the passage between the locking notch145and the mouth143in a slot141. It can be seen that the end162is set back relative to the front face142. Thus, the stud8can engage in the slot141prior to coming into abutment against the end162of the member161. Its second end, firmly secured to an annular portion167of the safety ring16, is connected to the free end162via a longitudinal blade163of radial thickness e163that is smaller than the radial thickness e162of the end162. The member161is preferably a catch that is elongate in the direction X-X so as to improve its flexibility and thus make it easier to deform when mechanical stresses are applied thereto.

Each catch161is formed integrally with the remaining portions of the safety ring16.

The catches161are adapted so that the in connected and disconnected configurations, their portions162and163are received respectively in a slot141close to the mouth143, and partially in the groove144that extends the slot.

In the disconnected configuration, the male and female elements2and4are separate, as shown inFIGS. 1 and 2. In order to connect them, the user moves the two elements2and4along arrows F1that extend parallel to the axis X-X. The coupling1is then brought into a “being-coupled” configuration as shown inFIGS. 3 and 4. Each locking stud8of the male element2is inserted simultaneously into the mouth143of one of the slots141of the locking ring14. Under the effect of axial forces in the directions of the arrows F1, each locking stud moves axially into the mouth143until it comes into abutment against the free end162of the catch161. This abutment causes the free end162of the catch161to be deformed radially. This deformation is due to the resilient bending of the catch161, and more particularly of its blade163. This bending releases a radial space in which the stud8can pass.

Under the action of forces that continue to be applied in the directions of the arrows F1, the locking studs8continue to advance along the slots141under the ends162until they engage in the locking notches145.

When the studs8reach the notches145and are no longer axially facing the corresponding catches161, the catches161return elastically to their initial configuration. Their respective free ends162come back into the slots141. The adjacent studs8are no longer exerting any mechanical stress in radial and axial directions on the catches161. This configuration of the catches161is shown inFIGS. 5 to 8and corresponds substantially to the above-described configuration of the catches when the coupling1is in the disconnected state. In all positions of the catches161, co-operation between the end162and the groove144serves to guide turning of the safety ring16relative to the locking ring14.

Once each stud8is received in a notch145, the coupling1is in the connected configuration as shown inFIGS. 5 to 8, in which configuration each catch161prevents the corresponding stud8escaping from the locking notch145in which the stud8is locked within the female element4against moving along the axis X-X. The valve members are both pushed back. Fluid can flow between the two pipes C1and C2that are connected to the male and female elements2and4, as represented by arrows E inFIG. 5.

In addition, the locking ring14is provided with an outer bearing surface148in alignment with the mouth143of the groove144and in contact with a first inner surface165of the free end162of the catch161. As shown inFIG. 3, when the male element2is engaging in the female element4, with the stud8advancing along the slot141, the catch161presses against portions of the outer bearing surface148. The bulky free end162moves backwards and slides along the outer bearing surface148, thereby contributing to the catch161deforming elastically in its blade163. Advantageously, the outer bearing surface148slopes towards a receiver mouth32of the female element4that serves to receive the male element2. Thus, the catch161is subjected to a smaller amount of stress in order to obtain the desired amount of bending. In addition, the angle of inclination P of the surface148relative to the longitudinal axis X-X lies in the range 30° to 60°, preferably in the range 40° to 50°, and more preferably is equal to 45°. An angle of inclination of 45° constitutes a good compromise for making it easier for the operator during a disconnection step both to move the free end162backwards and to retract the safety ring16.

A second radially-inner surface166of the free end162comes into contact with the locking studs8when the studs8engage in the slot141for connection purposes, and this surface166forms a sloping ramp or chamfer at an angle of inclination θ relative to the longitudinal axis X-X that lies in the range 30° to 60°, preferably in the range 40° to 50°, and more preferably is equal to 45°. The ramp slopes in the opposite direction to the mouth32. The presence of this chamfer enhances contact with the locking stud8and thus makes it easier for the catch161to deform radially under mechanical stress from the stud so as to make connection automatic.

A radius R1defined between a radially-outer surface164of the free end162and the longitudinal axis X-X, when the coupling1is in the disconnected or connected state, is less than a radius R2defined between a radially-outer surface147of the locking ring14and the axis X-X. In this way, the free ends162of the catches161, in the connected and disconnected positions, are protected by the locking ring14and do not run the risk of being damaged before they are used or while they are in use. As shown inFIGS. 2 and 6, the radial size of the safety ring16at the ends162is less than the radial size of the locking ring14.

Furthermore, the body12is provided with an outer annular collar36disposed at its periphery on a portion opposite from the mouth32. As shown inFIG. 3, while connection is taking place, the safety ring16can move backwards relative to the body12until it comes to bear against the collar36. This collar36thus forms an abutment that serves to ensure that the outer bearing surface148is in contact with the end162of the catch161when the safety ring16is moved backwards as far as possible. Thus, return of the catch161towards the connected and disconnected positions is automatic and therefore guaranteed.

In a variant that is not shown, the collar36may be provided on the locking ring14.

The safety ring16may be made of synthetic material. In addition to reducing the weight of the safety ring, the use of such a material enables complex shapes to be obtained, in particular by thermoforming.

Advantageously, the side surfaces168and169of a catch161are parallel to the axis X-X. These side surfaces168and169are parallel to the sides149and150of the groove144along which they extend in part. The sides149and150form receiver surfaces for receiving the side surfaces169and168of the catches161with which they are respectively parallel. As shown inFIGS. 2,4, and6, the side surfaces169and the sides149that are situated at the side of the slot141that is opposite from the notch slope with the same angle δ relative to a radial direction D passing through the middle of the bottom151of a groove144, i.e. halfway between the sides149and150in register with the bottom. The surfaces169and the sides149slope towards the notch145on going away from the axis X-X. The surfaces168and the sides150also slope relative to the direction D at an angle η. The surfaces168and169and the sides149and150are respectively mutually parallel, such that the angles δ and η have the same value. In a variant, these angles may be defined so that η is greater than δ so that deformation of the catch161can take place. The surfaces168and the sides150slope towards the notch145going away from the axis X-X.

Under such circumstances, deformation continues to be said to be radial even though the deformation of the catch161follows the direction of the inclination of the sides149and150of the groove144, in other words the deformation is radial, at least in part.

When a stud8is received in a notch145and the stud8tends to be expelled from the notch, the stud comes to bear against the side surface168of the adjacent catch161in the end portion162thereof. The catch161is in no danger of deforming sideways to any significant extent since its side surface169then comes to bear against the side149of the groove144. The side149thus forms an abutment preventing sideways deformation of the catch161. The inclination of the surface169and of the side149at the angle δ contributes to the desired blocking effect. In this way, the locking stud8is well held in the corresponding notch145when the coupling is in the connected state. Any force exerted by the stud8cannot cause the catch161to bend. Locking safety is thus reinforced.

To disconnect the male and female elements2and4, an operator pulls the safety ring16, and more precisely the annular portion167, towards the pipe C2until it comes into abutment against the collar36. The end162of the catch161then slides via its surface165over the surface148, thereby causing the catch161to deform radially. The end162releases a passage for the adjacent locking stud8. The stud8can then disengage from the locking notch145and move towards the mouth143of the slot141. Because of the forces exerted by the valve member22on the body6, the stud8then disengages from the adjacent locking slot141. The angle of inclination β, which is preferably equal to 45°, enables the operator to perform a single movement on the safety ring16in order to cause the ends162to bend.

When the operator lets go the safety ring16of the disconnected female element4, the deformed catches161return forwards, into their disconnected configuration as shown inFIG. 2, in which they obstruct the passages for the studs8between the mouths143and the notches145, and the coupling is ready for a further automatic connection operation.

In a variant of the invention that is not shown, the number of locking studs8is not necessarily equal to three. A male element may be provided that has at least one locking stud. If the male element has at least two locking studs, it is advantageous for them to be regularly distributed around the periphery of the surface of the element from which they project. The number and the spatial distribution of the slots141, the notches145, and the catches161match the number and the distribution of the studs8.

In addition, each locking stud8need not be formed integrally with the body6, but could be fitted to said body and secured by any appropriate means, such as adhesive or heat-sealing, for example. Furthermore, each locking stud is not necessarily cylindrical.

In another variant, the inner surface165is inclined, preferably at an angle of 45°, instead of and replacing the outer bearing surface148, with the orientation of the inclination of the inner surface165being identical to that described for the outer bearing surface148.

Furthermore, the catches161are not necessarily integral with the annular portion167.

Provision can also be made for the locking ring14to be prevented from moving in rotation and in translation relative to the body12, such that once the two coupling elements have been connected together, it is no longer possible for there to be any relative rotation between these two elements.

In a variant that is not shown, provision can be made for a locking notch to have a shape that enables the stud8to be locked axially in the female element. By way of example, the notch may be formed with sides that are perpendicular to the axis X-X. In this variant, the catch161does not serve to lock the stud axially in the locking notch, but serves to hold the stud in the notch in the event of relative movement between the two elements of the coupling.