FR2790056A1 - Pipe coupling has inner deformable claws and seal ring with toroid, cylindrical and conical surfaces - Google Patents

Abstract

The coupling consists of a tubular body (1) with one end connected to a pipe or other associated equipment, and the other containing deformable claws (12) and a seal ring (8) set in an annular recess (3) formed between stepped cylindrical surfaces. The seal ring has a toroid first surface (9) which interacts with the outer surface of the pipe, an outer cylindrical second surface (10) interacting with the inner cylindrical surface of the coupling body, and an inner conical third surface (11) which acts as a wedge to hold the claws in their gripping position. A pressure element (15) is used to open the claws for removing the pipe.

Description

The present invention relates to a connection device for the

  tight connection of one end of

  line to a member of a circuit for conducting fluids under pressure, such as another line, a tank, a pump, etc.

  Connection devices are known which comprise a tubular end piece having one end coupled to or integral with the member and a free opposite end.

  by which the pipe end is introduced. The em-

  tubular end is associated with means for sealingly securing the pipe end to it, which successively comprise, in a direction of introduction of the pipe end into the tubular end piece, means for retaining the pipe end and sealing means. In certain cases, these retaining means comprise a washer with deformable claws. Sealing is commonly ensured

  by an O-ring in a deformed elastomeric material

  ble received in an annular recess of the tubular end piece

  radially delimited by a cylindrical surface of it

  this. When introducing the pipe end into the tubular end piece, the pipe end is force fitted into the claw washer, the claws of which are then brought into a retaining position in which they are inclined and have a free end in abutment against an external surface of the pipe, and in the seal which is then crushed between the external surface of the pipe and the cylindrical surface of the

annular recess.

  When the circuit in which the connection device is installed is pressurized, this pressure has the effect of on the one hand pushing the tube backwards, movement possible because of the elasticity of the

  claws or teeth of the washer, and on the other hand to repel

  tighten the seal towards the deformable claws. It can then be seen that the seal rolls on itself and overlaps the claws, the seal then being moved away from the external surface of the pipe by the claws and no longer able to provide sealing. To prevent movement of the seal, sometimes a separating sleeve is placed between the O-ring and the claw washer, but the structure of the connection device is

then more complex.

  There therefore exists a need that has not yet been conveniently resolved for a connection device provided with

  means providing improved sealing.

  To this end, provision is made, according to the invention, for a

  connection device for the connection of an

  driving mite to a member, equipped with means for securing the pipe end to it in leaktight manner, these means comprising successively, in a tubular end piece coupled to the member and in a direction of introduction of the pipe end into the tubular end piece,

  deformable claws intended to be brought in from the outside

  pipe mite in a retaining position in which the claws are inclined and have a free end in abutment against an external surface of the pipe and an annular seal received in an annular recess radially delimited by a cylindrical surface of the nozzle tubular, the seal comprising a first substantially toric inner surface to cooperate with the external surface of the pipe and a second substantially cylindrical outer surface to cooperate with the cylindrical surface of the tubular end piece, the second surface being at least partially offset axially with respect to the first surface on the side of the claws. Thus, the second surface provides the seal with an offset support on the cylindrical surface of the annular recess which limits the movement and the rolling on itself of the seal towards the claws. Advantageously, the seal comprises a third substantially frustoconical interior surface, extending on the side of the second surface to cooperate in the manner of a wedge with the claws in the retaining position. The part of the seal delimited by the

  second and third surfaces thus form a corner provided-

  sant on the one hand to the seal a support on the cylindrical surface of the annular recess preventing the seal from moving and rolling on itself and constituting on the other hand a cam coming to apply the claws against the surface external of the pipe according to a force proportional to the pressure of the fluid circulating in the circuit, which reinforces the retention of the pipe end.

  Other features and advantages of the

  vention will emerge on reading the description which

  follows a particular non-limiting embodiment of the invention. Reference will be made to the accompanying drawings, in which: - Figure 1 is a longitudinal section view of a connection device according to the invention, and - Figure 2 is a partial view in longitudinal section of the connection device when 'a

  pipe end is connected to it.

  With reference to the figures, the connection device according to the invention is intended for the connection of a pipe end C to a member of a circuit for conducting fluid under pressure. This organ can be a fluid emitting or receiving organ such as another

  pipe end, pump, tank or other.

  The connection device comprises a tubular end piece 1 having a threaded end 1.1 intended to be implanted in the member and an opposite opposite end 1.2 by which the pipe end C is intended to be

  introduced into the tubular end piece 1.

  The tubular end piece 1 comprises a succession of three internal annular recesses 2, 3 and 4 of decreasing diameter in the direction of introduction of the end of

conduct indicated by arrow 5.

  The annular recess 4 has a diameter slightly greater than the diameter of the pipe end C to receive the latter in abutment against a shoulder 6 of the

annular recess 4.

  The annular recess 3 is delimited radially

  by a cylindrical surface 7 and receives a seal

  ring 8 in an elastomeric material.

  The seal 8 comprises a first inner surface 9 of toroidal shape. The surface 9 defines a passage section slightly smaller than that of the pipe end C. The seal 8 comprises a second substantially cylindrical outer surface 10 having a diameter substantially equal to that of the annular recess 3 to cooperate with the surface cylindrical 7 of the annular recess 3. The second contact surface 10 is partially offset axially with respect to the first surface

contact 9.

  A third interior surface 11 of frustoconical shape extends substantially at the level of the second surface 10. The second surface 10 and the third surface 11 converge towards one another on a side opposite to the first surface 9 to delimit a part having a wedge-shaped section along a radial plane of the seal. The second and third surfaces 10 and 11

  extend from the side of the annular recess 2.

  The annular recess 2 is connected to the annular recess 3 by a shoulder 12 against which a claw washer 13 is applied. The claw washer 13 is kept pressed against this shoulder by means of a locking ring 14 set in the end 1. 2 of the tubular end piece 1. A pusher 15 is

  slidingly received in the locking ring 14.

  When the pipe end C is introduced into the tubular end piece, it is force-fitted into the claw washer 12 and the seal 8 until it abuts the shoulder 6. The pipe end C then deforms the claws and brings them into a retaining position in which they are inclined and have a free end bearing against an external surface of the pipe. The part of the seal 8 having a radial corner section is then interposed between the claws in the retaining position and the cylindrical surface 7

of the annular recess 3.

  Under the effect of the pressure of the fluid circulating in the circuit in which the connection device is installed, the seal 8 is pushed towards the claw washer and acts as a wedge applying the claws against the external surface of the pipe. and

  thus strengthening the restraint exercised by them.

  The withdrawal of the pipe end C is carried out in a conventional manner by depressing the pusher 15 to spread the claws and thus free the pipe end. Of course, the invention is not limited to the embodiment described and it is possible to add to it

  variant embodiments without departing from the scope of the invention

  tion as defined by the claims.

Claims (2)

  1. Connection device for connecting a pipe end to a member, equipped with means for securing the pipe end therein in a sealed manner, these means successively comprising, in a tubular end piece (1) coupled to the deformable prongs (12) intended to be brought by the end of the pipe into a retaining position in which the prongs are inclined, according to a direction of introduction (5) of the pipe end into the tubular end piece and have a free end in abutment against an external surface of the pipe and an annular seal (8) received in an annular recess (3) delimited axially by a cylindrical surface (7) of the tubular end piece, characterized in that that the seal comprises a first interior surface (9) substantially toroidal to cooperate with the external surface of the pipe and a second exterior surface (10) substantially cylindrical for coop erect with the cylindrical surface (7) of the nozzle   tubular (1), the second surface being at least partial-   axially offset from the first surface on the side of the claws.   2. Connection device according to claim 1, characterized in that the seal comprises a third surface (11) substantially frustoconical interior extending from the side of the second surface (10) to cooperate in the manner of a wedge with the claws (12) in restraint position.