FR2556815A1 - COUPLING DEVICE FOR FLEXIBLE HOSE - Google Patents

Abstract

A SOFT HOSE COUPLING 3 INCLUDES A TUBULAR SLEEVE1 AND A CLAMP RING2. SLEEVE1 INCLUDES A PERIPHERAL RETAINING RIB5 OF WHICH AN ANTERIEUR FLAT7 IS SENSITIVELY TRUNCONIC. RING2 IS PIERCED BY RADIALLY UNINTERRUPTED SLOTS12. THESE SLOTS12 EXTEND OVER THE AXIAL LENGTH OF A POSTERIOR RAMP8 OF THE SAID RIB5, SENSITIVELY TRUNCONIC AND MADE OF ARDILLONS9. MEMBRURES13 SEPARATING THE SLOTS ARE ELASTIC IN THE RADIAL DIRECTION. BEFORE THREADING THE PIPE3 AND THE RING2 ON THE SLEEVE1, THE AVERAGE DIAMETER OF THE MEMBERS13 IS CONSTANT, AT LEAST OVER THE MAJOR PART OF THEIR LENGTH.

Description

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  EM: NT COUPLING DEVICE FOR FLEXIBLE HOSE

  The present invention relates to a delivery device

  plement for flexible pipe, comprising a tubular sleeve on which an end region of the flexible pipe is threaded, as well as an elastic clamping ring, said tubular sleeve externally comprising a peripheral retaining rib whose flank or anterior flat turned towards the the engagement end of the tubular sleeve is substantially frustoconical and is capped by the end region of the flexible pipe, and said clamping ring surrounding the end region threaded in the vicinity of the retaining rib, being provided at its axial ends with circumferential marginal regions closed and being pierced by radially uninterrupted slots, which extend in the axial direction of said clamping ring

  and are distributed evenly in the circumferential direction.

  In a known coupling device of this type, the rear ramp of the retaining rib, turned away from the engagement end of the tubular sleeve, is in a radial plane. The clamping ring has at its anterior and posterior axial ends a respective annular bead projecting inwards, the anterior bead pushing against the frustoconical flat part of the retaining rib the end region of the flexible hose threaded on the tubular sleeve, however that the posterior annular bead presses said end region against the cylindrical surface of said tubular sleeve contiguous to the radial flank of said retaining rib. The slots in the clamping ring are shorter, in the axial direction,

  that the axial length of the retaining rib, and the mem-

  notches inserted between these slots are relatively thick in the radial direction, their thickness increasing on the internal face in the direction of the ends, so that they are practically not flexible in the radial direction in addition to their short axial dimensions, and that the clamping force that they apply in the vicinity of the rib of

  restraint is relatively modest. These characteristics harm

  feels the sealing effect and the axial stop preventing the flexible hose from dislodging from the tubular sleeve. In the area between the posterior annular bead and the radial side of the retaining rib, there may be formed, between the cylindrical external surface of the tubular sleeve and the flexible pipe, a cavity in which no sealing effect is obtained. . Before the flexible pipe is threaded onto the tubular sleeve, the clamping ring is fitted onto this flexible pipe, after which said pipe and said ring are jointly threaded onto the sleeve. To allow easy threading of the flexible pipe and the clamping ring, at least the annular bead of this clamping ring, occupying an anterior position in the direction of the threading and projecting radially inwards, must have a internal diameter chosen appreciably larger than the external diameter of the retaining rib so that, possibly, the clamping force exerted in the threaded state between the annular bead

  anterior and the cylindrical outer surface of the sleeve tu-

  bular is too modest, despite the presence of the aforementioned cavity, to ensure sufficient sealing and axial locking. On the other hand, when the internal diameter of the anterior annular bead is chosen smaller, it is necessary to apply an extraordinarily large thrust force which cannot possibly be exerted, at least

by hand.

  The object of the invention is to provide a coupling device for flexible pipe of the aforementioned type, which guarantees sufficient sealing and axial locking, while allowing the flexible pipe and the clamping ring.

  to be more easily threaded on the tubular sleeve.

  According to the invention, this object is achieved by the fact that the slots (e the clamping ring extend

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  over a greater distance the axial length of the rear ramp of the retaining rib, turned away from the engagement end of the tubular sleeve; that the members located between these slots are endowed with elastic flexibility in the radial direction; that said rear ramp of the retaining rib is substantially frustoconical; and that the mean diameter of the clamping ring in the area of said members is constant, at least over most of their length, before the pipe is threaded

  flexible and the clamping ring on said tubular sleeve.

  The frustoconical configuration of the ramp of the retaining rib, oriented opposite the engagement end of the tubular sleeve, makes it possible to avoid the formation of a cavity between the flexible pipe and this tubular sleeve, and said 1S flexible pipe is pushed firmly against the retaining rib and the tubular sleeve, over a greater axial length, via the long members which flex radially outwards towards the retaining rib and apply elastic preload, this which provides both better sealing and better axial locking. In the case where there is therefore provided, at the anterior end of the clamping ring, an annular bead projecting radially inwards, the internal diameter of this bead can be chosen relatively large. If necessary, the presence of an annular bead

  protruding radially inward at the anterior end

  re of the clamping ring can become totally superfluous.

  Thus, the combined threading of the flexible pipe and the ring

  clamping on the tubular sleeve is facilitated.

  Likewise, the long elastic members facilitate this threading on the one hand and, on the other hand, they provide an elastic preload in a relatively long axial zone of the end region of the flexible pipe threaded on the tubular sleeve, so that the clamping ring can yield elastically in this zone as a result of thermal expansion of the material constituting the flexible pipe, and that it can recover its shape in the case of a contraction of said material constituting the flexible pipe, as a result of cooling. This further increases safety

sealant.

  It is also advantageous that the posterior ramp

  of the retaining rib is provided with peripheral barbs

  flattened risks. Axial locking is improved more

tage again.

  The barbs can be configured as sawtooth seen in axial section, and their side turned away from the engagement end of the tubular sleeve can be

  located in a radial plane. This configuration of ardil-

  lons facilitates on the one hand the threading of the flexible pipe and, on the other hand, it prevents to a particularly great extent this flexible pipe from dislodging or from skidding.

away from said tubular sleeve.

  Preferably, it is arranged that the slots extend at least over the entire axial length of the retaining rib. In this embodiment, the members elastically press the flexible pipe material against the retaining rib over the entire axial length of the latter, resulting in greater safety.

  sealing and better axial locking corresponding.

  It is furthermore favorable for the angle of inclination of the posterior ramp of the retaining rib to be smaller than that of the anterior flat part of this rib,

  when the axial lengths of these two flanks are approxi-

  matively identical, and that the external diameter of

  the engagement end of the tubular sleeve is sensi-

  considerably smaller than the internal diameter of the flexible pipe at rest, when the retaining rib is contiguous to this

  end of engagement. On the one hand, this facilitates the introduction

  tion of the tubular sleeve in the flexible pipe and, on the other hand, the threading of this flexible pipe. However, most of the flexible hose threaded over the tubular sleeve (especially the anterior end of this hose) is

  applied under the effect of its own preload against man-

  tubular cap, which increases the sealing effect.

  In addition, the axial length of the clamping ring can be dimensioned so that the end of this ring, turned away from the threaded end of the flexible pipe,

  is located before the engagement end of the sleeve tu-

  bular. In this way, the clamping ring prevents the material constituting the flexible hose from lifting away from the anterior frustoconical flat of the retaining rib, even when

  this flexible pipe is respectively deflected or bent radially-

  ment in front of the engagement end of the tubular sleeve.

  One of the circumferential marginal regions of

  the clamping ring can be applied against the front face

  tale of the threaded end of the flexible pipe. Under these conditions, said circumferential marginal region

  forms a stop preventing the clamping ring from being inserted

Too far on the hose.

  In addition, the clamping ring may have a diameter

  be internal constant over the length of the slots before the flexible pipe and the clamping ring are threaded onto the tubular sleeve. The manufacture of the clamping ring is thereby simplified and it is thus guaranteed that, in their axial central zone by which they cover the

  top of the retaining rib, the members are inflated

  flexed elastically and exert on the flexible pipe the

desired elastic load.

  By the way, the circumferential marginal region

  of the clamping ring located on the side of the post-boom

  of the retaining rib can be corrugated in the

  peripheral sense. This also allows a separation of the end

  mite the clamping ring located at the front in the direction of threading, and therefore facilitates this

threading.

  The above possibility may also be offered by

  the fact that the mean diameter of the clamping ring is cons-

  both over the major part of the axial length of this clamping ring before the flexible pipe and said ring are threaded onto the tubular sleeve; and that, in an intermediate zone connecting to said main part, and adjacent to the circumferential marginal region situated on the side of the rear ramp of the retaining rib, this diameter increases in the direction of said circumferential marginal region. In this case, it can be made so that the intermediate zone is bent radially backwards and outwards on the external face of the clamping ring, so that the circumferential marginal region, located on the side of the posterior ramp of the retaining rib,

  surrounds with a certain radial distance the main part

  abovementioned cipal. In this way, the clamping ring is permanently applied over its entire length to the pipe.

  flexible. It can however be flared at its anterior end.

  and can be easily put on the rib

  held together with said flexible pipe.

  The circumferential marginal region of the clamping ring located on the side of the rear ramp of the retaining rib may be discontinuous in the area

  between two neighboring members, and this disconti-

  night can be closed by a shutter element. This closure element of the clamping ring can then be

  open, before the flexible hose and said ring are

  spun on the tubular sleeve, to facilitate this threading. The closure element may consist of a lock

  snap-in. Such a lock can be easily manipulated.

  In particular, the shutter element may present, on either side of the discontinuity, bodies integrally molded and penetrating one into the other. he

  this results in a simple embodiment of the closure element.

  In addition, on either side of the discontinuity and in the vicinity of the latter, a respective projection can be produced on the circumferential marginal region having said discontinuity. These projections facilitate the closing of the closure element because, to this end, it

  just compress them in the peripheral direction.

  In this case, one of the projections can form one of the closing parts. We then dispense with an additional projection acting as a stop allowing the handling

  when closing the shutter element.

  The invention will now be described in more detail by way of non-limiting examples, with reference to the appended drawings in which:

  FIG. 1 is an axial section of a device conforming to

  mement to the invention for coupling a flexible pipe;

  Figure 2 is a radial section through a clamp ring.

ge of the device according to Figure 1;

  Figure 3 is a fragmentary representation in pers-

  pective of a second embodiment of a clamping ring of a coupling device according to the invention; Figures 4 to 9 are axial half-sections of other embodiments of clamping rings of coupling devices according to the invention mounted on a flexible pipe; and

  Figure 10 is a perspective view of another example.

  ple realization of a clamping ring of a device

coupling according to the invention.

  In the embodiment illustrated in Figures 1 and 2, the coupling device for flexible pipe consists of a tubular sleeve 1 and a clamping ring 2 of an elastic plastic material, between which a pipe

  flexible 3 is enclosed by the town, 4, of its extreme regions.

  The tubular sleeve 1 has a peripheral rib

  retainer 5, which begins at an engagement end 6 of the

  said sleeve 1 and ends substantially at the posterior end

  of this sleeve. The inclination of a side or flat

  frustoconical 7 of the retaining rib 5, adjacent to the end

  engagement mite 6, is slightly larger than the incli-

  origin of a posterior sidewall or ramp 8 which is turned

  opposite of said end 6 and is provided with peri-barbs

  flattened spheres 9. The external diameter of the tubular sleeve 1 at the engagement end, measuring approximately 28 mm, is slightly smaller when read the internal diameter (approximately 29 mm)

  flexible hose 3 at rest, so as to facilitate donning-

  ment of this pipe 3. The external diameter at the end

  posterior of sleeve 1, measuring approximately 31 nmm, is sensi-

  considerably larger than the internal diameter of the flexible pipe 3 at rest. The sides 7 and 8 have approximately the same length of 20 mm in the axial direction and an inclination of approximately 7 or approximately 3, respectively. The diameter

  maximum external of the retaining rib S measures approximately 33 mm.

  The section of the barbs 9 is substantially configured as a sawtooth. Their tapered flank turned away from the engagement end 6 extends over an axial length of approximately 1.5 mm, their radial flank extending over approximately 0.4 mm. The angle of inclination of the frustoconical sides of the

  barbs therefore measure roughly 15.

  The clamping ring 2 has four uninterrupted slots 12

  radially broken, which extend to regions

  circumferential margins in the form of annular beads

  tracks 10 and 11, are delimited by thin members

  axial 13 and are distributed at equal intervals over the

  turn of said clamping ring 2. These slots show a wid

  about 1 mm thick. The annular beads 10 and 11 are closed in the peripheral direction. The annular bead 11 is applied, by a wing projecting radially inwards, against the front face 14 of the extreme region 4, so that the clamping ring 2 cannot be threaded further on this extreme region 4. In place of this wing, the flexible pipe 3 may also have, on its external face, an annular bead 15 serving as a stop for the clamping ring 2. The removal of the wing from the annular bead 11 projecting radially towards the interior, as well as the production of the two annular beads 10 and 11 with the same internal diameter as the members 13, further facilitate the manufacture of the clamping ring 2 and the threading of this ring 2 on the flexible pipe 3, same as threading

  joint of said pipe 3 and said ring 2 on the tubular sleeve

  area 1, over the retaining rib 5.

  The slots 12 extend at least over the axial length of the barbed ramp 8, preferably, however, over a distance exceeding the entire axial length of the rib of

  retainer 5, as shown. The annular bead 10 is found

  ve therefore before the engagement end 6. The internal diameter of the clamping ring 2 in the vicinity of the slots 12, measuring about 28 mm, is substantially equal to the external diameter of the flexible pipe 3 at rest, which diameter is turn larger than the maximum external diameter

of the retaining rib 5.

  The flexible hose coupling shown on the

  Figures 1 and 2 offer the advantage that the re-

  extreme region 4 of the flexible pipe 3 is pressed along its entire axial length against the tubular sleeve 1 and in that,

  due to the elasticity of the members13, the material

  killing said end region 4 of the pipe is subjected to a pre-

  elastic load. This elastic preload ensures

  the wedge of the clamping ring 2 becomes smaller due to thermal expansion of the material constituting the flexible pipe, and it avoids excessive compression of this material. It thus acts against a lasting deformation of said material constituting the pipe. On the other hand,

  a firm contact of the pipe on the tubular sleeve 1 is ensured

  d even after thermal expansion of the material of the pipe and after subsequent cooling accompanied by a contraction of said material, because the members

  elastic resiliently return to their original position.

  Because the clamping ring 2 is chosen longer than the end region 4 of the flexible pipe 3 (so that this ring 2 extends beyond the engagement end 6, to the left while observing FIG. 1) , said end region 4 is prevented from lifting radially away from the tubular sleeve 1, in particular from the anterior flat 7, when said pipe 3 is deflected (bent) radially in front of said sleeve 1. Under these conditions, the ring of tightening 2 gives, in concert with the frusto-conical and notched embodiment of the rear ramp 8 of the retaining rib 5, great security preventing an axial dislocation or skidding of said end region 4 away from the sleeve 1, as such could be the case when a high fluid pressure 1 (3 prevails inside said pipe 3, or else a large force

  axial is applied from the outside.

  Prior to threading the pipe 3 on the sleeve 1, the clamping ring 2 is engaged in its position illustrated on this pipe 3. Then the pipe 3 and the ring 2 are

  jointly threaded on the tubular sleeve 1, an adhesive

  rette 16, located at the rear end of said sleeve 1 (or else a wall, corresponding to this collar 16, of a housing to which said sleeve 1 is for example connected in one piece), then acting as a stop and preventing unl threading too advanced. In other colors, it is thus guaranteed that the posterior end (annular bead 10) of the clamping ring 2 comes to be placed outside the

sleeve 1.

  FIG. 3 represents, by a perspective on an enlarged scale, part of a second embodiment of a tightening ring 2a. This ring 2a can be used

  instead of the clamping ring 2 of the coupling device-

  ment according to Figure 1, and also consists of an elastic plastic. Instead of annular beads 10

  and 11, this ring has circumferential marginal regions

  closed ferentials 10a and lla. The marginal marginal region

  11a located on the side of the ramp 8 of the retaining rib 5 is corrugated in the peripheral direction, the other circumferential marginal region 10a being smooth. In addition, this ring 2a is also pierced with axial slots 12a delimited by members 13a. The axial lengths of the ring 2a and of the slots 12a, as well as the internal diameter,

  can correspond to those of the clamping ring 2.

  In this exemplary embodiment, the corrugated circumferential marginal region 11a facilitates the threading of the clamping ring 2a over the retaining rib 5. In addition,

  it offers the same advantages as the first example of reali-

station.

  Figures 4 to 9 show other examples of embodiments.

  the clamping ring on the flexible hose 3. For all clamping rings 2b to 2g, the mean diameter (value

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  mean internal and external diameters) is constant over a main part of the axial length of the clamping ring, before the flexible pipe 3 and the ring 2b to 2g are threaded on the tubular sleeve 1 according to FIG. 1, no shown in Figures 4 to 9. In an intermediate area connecting to this main part, and adjacent to a circumferential marginal region 11b to 11g located on the side of the rear ramp 8 of the rib

  S according to figure 1, the mean diameter increases in direction

  tion of this region 11b to 11g, so as to facilitate threading of the flexible pipe 3 and the clamping ring 2b to 2g on the sleeve 1, over said rib 5. On

  Figures 4 to 9, the slots and the frames are respectively

  vely identified by 12b to 12g and 13b to 13g.

  In the exemplary embodiments according to FIGS. 4 and 5, the circumferential marginal regions 11b and

  11c extend parallel away from the peri-surface

  of the flexible pipe 3 (at rest), which means that the edges of said regions 11b and 11c, located at the front when threading on the tubular sleeve 1, lie in the plane of the front face 14 of the extreme region 4

of said pipe 3.

  On the other hand, in the exemplary embodiments according to FIGS. 6 to 8, the circumferential marginal regions 11d to 11f, located at the front when threading on the sleeve 1, are applied against the front face 14, so that they serve as stops preventing threading

  too tight of the clamping ring on the flexible pipe 3.

  In the embodiment according to FIG. 9, the curved intermediate zone is curved radially backwards and outwards on the external face of the ring

  tightening 2g. Therefore, the circumferential marginal region

  11g, located on the side of the rear ramp 8 of the retaining rib after threading on the sleeve

  tubular 1, also surrounds the radial distance

  main tie of the tightening ring 2g having the constant diameter (before threading). The frames 13g 1'2 are however applied at an axial distance more

long against soft tiluan 3.

  According to FIG. 10, a circumferential marginal region-

  11h of a 2h tightening ring, located at the front relative to the direction of threading, has a discontinuity 17 in the vicinity of one of the slots 12h1 or between two neighboring members 13h, respectively. The slots 12h are further closed at their ends because a posterior circumferential marginal region 10b, as well as the remaining area of said marginal region 11h, are produced.

  uninterrupted in the peripheral direction. When putting on-

  ment of the flexible hose 3 and the clamping ring 2h on the tubular sleeve 1, the discontinuity 17 is opened to facilitate this threading, then it is closed by a

  obturation element 18 after this threading.

  The shutter element 18 consists of a latching or snap lock comprising two shutter parts and 21, in the form of substantially radial projections integrally molded on the marginal region.

  circumferential 11 o'clock, on either side of the discontinuity

  tee 17. One, 20, of these closure parts is in clearance on the side facing the discontinuity 17, which

  roughly gives it the shape of a question mark

  gation. The other sealing part 21 has a substantially shorter radial length than that of the part 20, and it has a draft on its side turned away from the discontinuity 17. Another radial projection 22, also coming from molding at proximity of the discontinuity 17 on the stripped side of the closure part 21, facilitates closing. In this case, the projections 20 and 21 are compressed in the peripheral direction, by hand or by means of a tool, until the section of the closure part 20, in slight radial projection towards the inside. ,

  has slipped past the shutter part 21 and imprisoned-

  do not over the skin of this part 21. If desired, the shutter can be opened again by bending radially outward, by means of a

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  tool, the radial section of the closure part 20.

  Nozzles 23 of the circumferential marginal region

  11h, which project radially inwards, apply

  quent against the front face 14 of the end region 4 of the flexible hose S 3, when threading the tightening ring 2h, in order to prevent this ring 2h from being threaded too far

on said pipe 3.

  Variants of the exemplary embodiments shown may consist, for example, in that the clamping ring 1 ′) 2 of the type of embodiment according to FIGS. 1 and 2 has, in place of the annular bead 11, a substantially circumferential marginal region hooked, which first extends approximately radially inward, then approximately axially forwards towards the axially opposite end of the clamping ring 2, so that

  its section (in ul axial plane of said ring 2) has sensitive-

  the shape of a lying U. Furthermore, in all examples

  ples of realization, the members may have a section substantially U or substantially elliptical instead

  of a rectangular section. In addition, teeth fit

  laying on the barbs 9 can also be provided on the anterior flat 7 of the retaining rib 5, or else

only on this flat 7.

  -It goes without saying that many modifications can

  be made to the device described and shown, without

from the scope of the invention.

255681S

1.1

IRET: ND I CTI0NS 1. Coupling device for flexible hose, compre-

  nant a tubular sleeve on which an end region of the flexible hose is threaded, as well as an elastic clamping ring, said tubular sleeve externally comprising a peripheral retaining rib whose front flank or flat face facing the engagement end of the sleeve tubular is substantially frustoconical and is capped by the end region of the flexible pipe, and said clamping ring surrounding the end region threaded in the vicinity of the retaining rib, being provided at its axial ends with circumferential closed marginal regions and being pierced with uninterrupted slots radially, which extend in the axial direction of said clamping ring and are distributed uniformly in the circumferential direction, device characterized in that the slots (12; 12a - 12h) of the clamping ring (2; 2a - 2h ) extend over a distance greater than the axial length of the rear flank or ramp (8) of the retaining rib (S), turned away from the end sleeve engagement moth

  tubular (1); by the fact that the members (13; 13a -

  13h) located between these slots are endowed with elastic flexibility in the radial direction; by the fact that said rear ramp (8) of the retaining rib (5S) is substantially frustoconical; and by the fact that the average diameter of the clamping ring in the area of said members [13; 13a - 13h] is constant, at least over the nm part of their length, before threading the flexible pipe [3] and the clamping ring [2

  2a - 2h] on said tubular sleeve [1].

  2. Device according to claim 1, characterized in that the rear ramp (8) of the rib of

  retainer (5) is provided with flattened peripheral barbs (9).

  3. Device according to claim 2, characterized in that the barbs (9) are configured as teeth

  saw observed in axial section, their flank facing the opposite

  dried from the engagement end (6) of the tubular sleeve

  (1) being located in a radial plane.

  4. Device according to any one of the claims

  1 to 3, characterized in that the slots (12; 12a -

  12g) extend at least over the entire axial length of

the retaining rib (5).

  5. Device according to any one of the claims.

  1 to 4, characterized in that the angle of inclination

  the sound of the rear ramp (8) of the retaining rib (5) is smaller than that of the front flat (7) of this rib; by the fact that the axial lengths of these two flanks (7, 8) are approximately equal; and

  by the fact that the external diameter of the engagement end-

  ment (6) of the tubular sleeve (1) is substantially smaller than the internal diameter of the flexible pipe (3) at rest, when the retaining rib (5) is contiguous to said

end of engagement.

  6. Device according to any one of the claims

  1 to 5, characterized in that the end of the clamping ring, facing away from the threaded end of the flexible hose, is located before the engagement end (6)

tubular sleeve (1).

  7. Device according to any one of the claims

  1 to 4, characterized in that one (11; lld - 11f; 11h) of the circumferential marginal regions of the clamping ring is applied against the front face (14) of

  the threaded end of the hose.

  8. Device according to any one of the claims

  1 to 7, characterized in that the clamping ring (2; 2a) has a constant internal diameter over the length of the slots (12; 12a) before the flexible pipe (3) and said clamping ring ( 2; 2a) on the tubular sleeve

(1). -

  9. Device according to any claim

  1 to 8, characterized in that the circumferential marginal region (11a) of the clamping ring (2a) located on the side of the rear ramp (8) of the retaining rib

  (5) is wavy in the peripheral direction.

  10. Device according to any one of the claims

  1 '. 1 to 7, characterized by the fact that the mean diameter of the clamping water (2a - 2gl is constant over a main part of the oexial length of this clamping anecau before the flexible pipe (3) and said ring (2a - 2g) are threaded onto the i ;; tubular anclhcn (1); and by the fact that, in an intermediate zone connecting to said

  main part, and adjacent to the circumferential marginal region

  (11b - 11g) located on the side of the post-boom

  lower (8) of the retaining rib (S), this diameter

  increases towards said circumferential marginal region

differential (11b - 11g).

* 11. Device according to claim 10, characterized

  by the fact that the intermediate zone is radially curved

  backwards and outwards on the outside of the clamping ring (2g), so that the marginal region

  circumferential (11g), located on the side of the posterior ramp

  re (8) of the retained rib dc, radially surrounding h

distance the main part.

  12. Device according to any one of claims

  1 to 7, characterized in that the marginal region circulates

  (11h) of the clamping ring (2h) located on the side of. the posterior ramlpe (8) of the retaining rib is discontinuous in the zone between two adjacent members (13h), this discontinuity (17) being able to be closed

by a closure element (18).

  13. Device according to claim 12, characterized in that the closure element (18) consists

by a snap lock.

  14. Device according to claim 13, characterized in that the closing element (18) has, on either side of the discontinuity (17), parts (20,

  21) integrally molded and interpenetrating.

  15. Device according to claim 14, characterized in that a respective projection (20, 22) is produced on the circumferential marginal region (11h) having

  the discontinuity (17), on either side of this disconti-

  night (17) and near the latter.

  16. Device according to claim 15, characterized in that the tune (20) of the projections forms one of the

shutter parts.