FR2783589A1 - Tube connection method to a body provided with a channel using a deformable clamping screw - Google Patents

Abstract

The fixing of a pipe (C) to a body (1) with a through hole (2) consists of an extended terminal part (3) on the body (1) which has a threaded part (4) and an extension (5) for receiving the end of the tube. The coupling is effected by a nut (10), threaded to engage with the threaded part of the body. Part of the nut opens out radially when being screwed down whilst the other end (17) closes radially as the expansion of the end (16) increases.

Description

The present invention relates to means for connecting a pipe to

  a body in which a channel is formed. Such connection means are by

  example intended for use in conduction circuits

  pressurized liquors to connect two elements of the circuit to each other, such as pipes, or a pipe to an emitting or receiving member of a liquid. There are known connection ends of a pipe which have an end portion through which a channel opens into a recess intended to receive

  one end of the pipe so as to communicate

  cation the interior space of the pipe with the channel. The terminal part has an external thread to cooperate with a nut comprising deformable means

  radially clamping the pipe in the recess.

  The clamping means generally consist of a deformable metal ring mounted in the nut against a shoulder thereof so that, when the nut is screwed onto the external thread, the ring is clamped between the shoulder of the nut and the end of the end part of the nozzle. The clamping force causes a radial retraction of the ring which is thus crimped onto the pipe. The ring then simultaneously maintains

  from the end of the pipe in the recess and the watertight

connection cost.

  A drawback of such a connection lies in the fact that the end of the pipe is mounted with play in the recess. There is therefore a space between the bottom of the recess and the end of the pipe, and between the internal cylindrical surface of the recess and the external surface of the pipe. During the circulation of a liquid in the connection area, part of the liquid enters this space and stagnates there constantly. This

  space therefore constitutes a liquid retention zone.

   , The liquid retained may dry out and form flakes which, when liquid circulates again in the connection area, will be inserted into the liquid flow. In the case of paints, the glitter may block projection nozzles or be deposited on the surface to be painted, degrading the state of

surface obtained.

  Furthermore, in the case of feed liquids

  res, the liquid retained in the retention zones deteriorates and pollutes the liquid subsequently circulating in the connection zone. The cleaning of such retention areas

  is extremely difficult to achieve.

  There therefore exists a need that has not yet been conveniently resolved for connection means ensuring

  the tightness of the connection by limiting or even eliminating

  mant the fluid retention areas.

  To this end, according to the invention, means are provided for connecting a pipe to a body in which a channel is formed, comprising a tubular end part of the body extending said channel, provided with an external thread and equipped with means for receiving one end of the pipe, and comprising a nut having a central axis and cooperating with the external thread, the nut comprising radially deformable means for clamping the end of the pipe in said reception means during the screwing of the nut on the external thread, the reception means comprising an end portion of the tubular end portion intended to be engaged in the end of the pipe to be connected, and the nut comprises in its direction axial a first radially expandable tapped section and a second radially retractable section in response to the expansion of the first section when it is screwed onto the external thread. Thus, the second section of the nut closes on the pipe to pinch it between it and the

  end portion of the tubular end portion.

  Sealing is thus ensured at this end portion, so that it is possible to limit

the extent of the retention zones.

  Preferably, the tubular end part of the body has a shoulder on which the nut abuts at the end of its screwing. This ensures a precise position of the nut on this tubular part such that the free edge of the second section of the nut extends substantially opposite an end edge of the end portion. Sealing is then ensured at

  level of this extreme edge so that there is not sensitive-

no retention zone.

  According to a particular embodiment, the first and second sections of the nut are in the form of split sleeves longitudinally joined by an annular central part, the slots of one section being in the extension of the slots of the other section. The structure of the connection means is then particularly simple and comprises only a limited number of parts,

thus facilitating its realization.

  Advantageously, the end portion of the tubular end portion comprises an external chamfer and / or an internal chamfer. The external chamfer prevents the pipe from being damaged by the end portion due to the force exerted by the nut on the pipe at this level. The internal chamfer allows a progressive connection of the internal surface of the channel with

that of driving.

  Other features and advantages of the

  vention will emerge from reading the following description

  particular nonlimiting embodiments of

the invention.

  Reference will be made to the appended drawings, among which: - Figure 1 is an elevational view, with longitudinal half-section, of a connecting piece of a pipe before clamping the pipe, the end piece comprising means of connection according to the invention, - Figure 2 is a view similar to Figure 1 of this connecting piece after clamping the pipe, - Figure 3 is a detail view of the area indicated by arrow III in the figure 2, - Figure 4 is a top view of a nut according to the invention, - Figure 5 is a perspective view of this nut, - Figure 6 is a view similar to Figure 2

  a connection end piece according to an alternative embodiment

tion of the invention.

  We can see in Figures 1 and 2 a tip for connecting a pipe C to an element of a circuit

liquid not shown.

  The connection end piece according to the invention comprises a body generally designated at 1 in which a channel 2 is formed. The connection end piece is here made of stainless steel but can be made of any other

  material such as chemical nickel-plated brass.

  The body 1 comprises an end portion 3,

tubular, extending channel 2.

  An external thread 4 extends around the

  end part 3. The thread 4 is conical.

  The end part 3 is extended, on its side opposite to the rest of the body 1, by an end portion 5

that also crosses channel 2.

  The end portion 5 has a substantial diameter.

  ment equal to the internal diameter of the pipe C. This diameter is less than that of the terminal part 3 and the

  end portion 5 is connected to this terminated part

nal by a shoulder 13.

  The end portion 5 has an end edge 6 provided with an external chamfer 7 and an internal chamfer 8. The external surface of the end portion 5 has an annular step 9 here in the form of a fir tooth . The part 14 of the body 1, which is opposite the end part 3 and separated from the latter by an intermediate part 15 of polygonal cross section to cooperate with a tool such as a flat wrench, may have a structure identical to the part terminal 3 to be connected to another pipe or, as shown in Figure 1, have an externally threaded portion for

  be installed in the element of the liquid circuit.

  The connection end piece also includes a nut generally designated at 10 and intended to cooperate with the thread 4 of the terminal part 3. The nut 10 is here

  made of the same material as the body 1.

  With particular reference to FIGS. 4 and 5, the nut 10 has a central axis 11 and has an internal diameter greater than the external diameter of the

  line C to be connected. The nut 10 has a substantial length-

  equal to the cumulative lengths of the terminal part 3

and the end portion 5.

  The nut 10 comprises two coaxial sleeves 16 and 17, each defining a section of the nut, joined by an annular central part 12. The annular part 12 has, in cross section, an external contour

  polygonal to cooperate with a tool such as a flat wrench.

  The slots 18 of the sleeve 16 and the slots 19 of the sleeve 17, as well as the parts 21 of the sleeve 16 and the

  parts 22 of the sleeve 17 individualized by the slots 1835 and 19, extend in line with one another.

  A.-, The sleeve 16 has a thread 20 and the

  sleeve 17 here has a smooth internal surface.

  With reference to Figures 1, 2 and 3, for connection

  der a pipe C to a circuit element, the part 14 of the body 1 is previously screwed into the element. The end of the pipe is then introduced into the nut 10

  on the side of the section delimited by the sleeve 17.

  The end portion 5 of the terminal part 3 is then fitted into the end of the pipe C until the end of the pipe C comes into abutment

against shoulder 13.

  The sleeve 16 of the nut 10 is screwed onto the thread 4. Due to its taper, the thread 4 gradually exerts a force on the parts 21 of the sleeve 16 tending to separate them from each other. The tabs 23 of the annular part 12 extending at the level of the slots 18, 19 deform, which leads to a tilting, around these tabs, of the parts 21, 22 of sleeves 16, 17 in alignment. The section of the nut 10 delimited by the

  sleeve 16 gradually expands while simultaneously

  nement narrows the section delimited by the sleeve 19, the parts 22 of the sleeve 17 approaching each other. It is understood that the parts 21, 22 of the sleeves 16, 17 in alignment behave like levers whose axis of rotation is located at the legs 23 of the part

annular 12.

  As the nut is tightened, the parts 22 grip the external surface of the pipe C and apply the end of the pipe C against the shoulder 13. The parts 22 simultaneously cause a radial deformation of the pipe C tightening it on the end part 5. It will be noted that the division of the sleeves of the nut into six parts makes it possible to exert on the pipe a tightening force uniformly distributed around the periphery of

this one.

  Once the nut 10 abuts against the shoulder formed by the end of the thread 4, or against the intermediate part 15 the ends of the parts 22 forming the free edge of the sleeve 17 are located substantially opposite the extreme edge 6 of the end portion 5. The parts 22 press and deform the pipe C against the end edge 6 so that the internal surface of the pipe C substantially matches the shape of the external edge 6 as best seen in the figure 3. The connection is therefore sealed at the extreme edge 6. In FIG. 3, it can also be seen that the internal chamfer 8 provides a progressive connection of the internal surface of the channel 2 with that of the pipe C. We can provide that the elastic limit of the annular part is exceeded during the deformation of the nut 10, in particular when it is desired that the nut does not

  can be reused after disassembly.

  As a variant and in accordance with FIG. 6, a conical portion 24 is formed on the end portion 3 on the side of the intermediate portion 14, the conical portion 24 opening out from the end of the thread 4 to the intermediate portion 15. The conical portion 24 thus forms an expansion corner of the sleeve 16 increasing

  still the deformation of the nut 10.

  Advantageously, an internal annular step 25 in fir tooth is provided near the free edge of the sleeve 17 to improve the grip of the external surface of the pipe C by the parts 22 of the sleeve. The end portion 5 is here externally smooth but could have, as before, an external annular step. 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-35 tion as defined by the claims.

 ,

  Thus, a 4-cylinder thread can be produced.

  that and a tapered thread 19, or a thread and a

tapered thread.

  In addition, the nut may present on all of its

  length of a polygonal external contour in cross section

the.

Claims (6)

RESELL I CATIONS   1. Means for connecting a pipe (C) to a body (1) in which a channel (2) is formed, comprising a tubular end portion (3) of the body (1) extending said channel (2), provided with '' an external thread (4) and equipped with means for receiving one end of the pipe, and comprising a nut (10) having a central axis (16) and cooperating with the external thread, the nut comprising   radially deformable means for clamping the end   mity of the pipe in said reception means when the nut is screwed onto the external thread, characterized in that the reception means comprise an end portion (5) of the tubular end portion intended to be engaged in the end of the pipe to be connected, and in that the nut (10) comprises in its axial direction a first section (16) tapped radially expandable and a second section (17) retractable radially in response to the expansion of the first section when screwed on the external thread.   2. Connection means according to claim 1, characterized in that the terminal part (3) has a shoulder on which the nut (10) abuts at the end of its screwing.   3. Connection means according to claim 1 or claim 2, characterized in that the first and second sections (16, 17) of the nut (10) are in the form of a split sleeve longitudinally joined by an annular central part (12 ), the slots (18, 19) of a section being in the extension of the slots (19, 18) of the other section.   4. Connection means according to one of the res-   dications 1 to 3, characterized in that the end portion   mite (5) of the tubular end part (3) comprises a outer chamfer (7).   5. Connection means according to one of the res-   dications 1 to 4, characterized in that the end portion   mite (5) of the terminal part (3) has an inner chamfer (8). 6. Connection means according to one of the res-   above, characterized in that an annular step (9) of fir tree type extends around the part   end (5) of the tubular end portion (3).