FR2620649A1 - Apparatus for clamping two workpieces, in particular for welding them together - Google Patents

Abstract

The invention relates to an apparatus for holding two workpieces in close contact with each other, with an adapted clamping force, in particular so as to make it easier to weld them together. In order to provide a predetermined clamping force, the apparatus comprises means 5, 9 for bearing against two substantially opposed sides of the two workpieces 2, 3, first clamping means 4, 6, 8, 17, 20 for exerting on the said bearing means 5, 9 a force moving them together which is less than the predetermined clamping force which it is desired to reach and, linked to the said first means, second clamping means 12, 14, 17, 20 for exerting, on these same bearing means 5, 9, an additional force so as to reach the desired force for clamping the two workpieces 2, 3 together. The invention is particularly intended for the preparation for the welding together of a gas main and a branch-off connector ("saddle tee").

Description

 The invention relates to an apparatus for maintaining close contact One of the other of two parts, such as a pressurized gas pipe and a connection socket respectively, with a suitable clamping force, in particular in order to facilitate Their welding.

 Welding between them many parts often poses, as we know, delicate problems to be solved, in particular in the case where it is necessary to come to weld or more exactly heat seal, a connection socket, for example made of polyethylene, on a pipe which can also be made of polyethylene and used for the distribution of pressurized fuel gas.

In fact, practically every manufacturer has established precise rules for best welding their parts. As a result, the user is led in practice to have to adapt frequently, according to each type of material,
The standards he must use to pre-lock the pieces.

In addition, it should be remembered that in the case of gas pipelines, these are usually buried in the ground and that it is then necessary to intervene most of the time in the bottom of the hole which has been dug around channeling so as to allow
The intervention, which makes the operation delicate.

 So far, the devices offered have not been entirely satisfactory.

 In fact, first of all, they proved to be difficult to set up, given the relative narrowness of the hole, which in general cannot be enlarged at will without causing discomfort for the pedestrian automobile environment ...) , since Interventions are often carried out in urban areas.

 However, it is necessary that the entire intervention can be carried out easily, without any particular risk of human error or material defect, taking into account the risk that a welding defect would present, which could lead for example to leaks from gas.

 In addition, the devices offered were not versatile, that is, they were only suitable for working on a specific type of part.

 The object of the invention is to solve these various problems.

To this end, the apparatus of the invention is characterized in that, in order to ensure a determined clamping force of these two parts together, it comprises
support means coming to bear against two opposite sides of the two parts to be kept in close contact,
first clamping means for exerting on said bearing means a closing force less than the determined clamping force which one wishes to achieve,
- And, Related to said first means, second clamping means for exerting on these same support means, an additional force also determined, so as to achieve the desired clamping force of the two parts together.

 Thus, we can effectively apply to the parts a constant force determined corresponding to that recommended by the manufacturer, and this if necessary repeatedly, as and when interventions.

Preferably, the aforementioned second clamping means will comprise
- elastic compression means linked to one of the support means, to exert in their compressed state, a force substantially equal to the desired clamping force,
- And means to bring and maintain in their compressed state said elastic means.

 It will also be noted that in the case where the two parts to be clamped are effectively a pipe for pressurized gas and a connection socket, one of the support means will be interchangeable and will include a multi-stage cone-shaped holding pad. one of the stages of which will engage in the free end opposite the connection socket, while the other support means will come to bear directly against an opposite part of said pipe.

 This will ensure the device real versatility to intervene on different types of parts to assemble, or more exactly to weld, regardless of the model or manufacturer.

The invention will appear more clearly from the following description made with reference to the accompanying drawings in which:
FIG. 1 is a front view in cross section of the apparatus of the invention,
FIG. 2 is a sectional view along the line II-II of FIG. 1,
- Figure 3 is a possible embodiment of One of the support means of the apparatus illustrated in Figure 1, this means being intended to come to bear on
One of the rooms,
- Figure 4 is an alternative embodiment of
The invention incorporates extensions allowing an operator to intervene remotely and to control the device from outside a hole dug around the pipe.

 If we refer first to Figure 1, we see the device 1 of the invention in the intervention position on a pipe 2, for example polyechylene, distribution of pressurized gas on which we want weld another part marked 3, such as a polyethylene connection socket.

 As already noted, other interventions on different types of parts could of course be considered.

 Let us keep the example of a gas distribution pipe on which we want to weld a plug 3 connection.

 To ensure a suitable clamping force and obtain a suitable quality of welding conform to the standards defined by the manufacturer, the apparatus of the invention comprises two sets of clamping means which can develop different forces but which cooperate with each other. other.

 More precisely, to exert on the two parts to be assembled, firstly a first force tending to bring them closer together, this clamping force nevertheless remaining less than that recommended by the manufacturer for carrying out the welding, the apparatus 1 comprises a rod 4 pro Longed at one end by a hooked tab 5 which, in the case illustrated in FIG. 1, is in the form of a vee coming to bear against the lower part of the pipe '2.

The rod 4 is notched along a generator and comes to cooperate at the level of a passage 18 formed in a part 8, with a pawl 6 recalled by a spring 7 and mounted in this same part 8. The part 8 in question forms in fact connecting piece and is mechanically connected to a support or holding pad 9, by means of a system forming the second set of aforementioned clamping means on
Which we will come back to. Skate 9 comes to engage in
The orifice 23 of the barrel 13 of the outlet 3, at its opening end, and this appreciably in opposition to
The abovementioned support tab 5, so that one can exert an axial clamping force without causing any particular deformation of the parts.

 As we have understood, the connecting piece 8 is movable in relation to the rod 4 substantially parallel to the axis 10 of application of the clamping force which passes through the two support pieces 5 and 9 .

 In addition, according to the invention, so as to facilitate the disengagement of the notches of the rod 4 of the catch 6, this same rod 4 is movable in rotation around the axis 14 of transLation of the part 8 thus making it possible to easily release the tension rod, a priori at the end of the welding operation. In this regard, it will be noted that to facilitate its handling The rod is provided on the side of its end opposite to the hooked tab 5 with a handle 11 for operating here bent.

 Let us now turn to the second clamping means which will allow, after the rod 4 has been maneuvered, thus exerting the first abovementioned approach force, to apply a complementary force so as to reach the force recommended by the manufacturer.

These second means comprise a slide 12 mounted movable in translation relative to the piece of
Connection 8, substantially in the clamping axis 1C of the two parts. The slide 12 extends through a through orifice 28 formed in the part 8 and comprises a threaded part 1Za which extends it towards the outside of the part 8, in the direction of the parts to be clamped.

As illustrated, an operating part 14 comes to cooperate via a tapped part 14a with
The threaded part 1Za of the slide, in a rotational movement around the axis 1C of transLation of this same slide. The rotating operation of the part 14 is facilitated by a lever 15.

 A pin 16 (see also FIG. 2) or equivalent, fixedly mounted on the connecting piece 8 extends on one side in a slot 22 formed in the neck 12, and, on the other, in a groove 24 formed in look into the operating part 14 sensitively in its plane of rotation 34, so as to limit the magnitude of the pivoting movement by virtue of the two stops 24a, 24b at the bottom of the groove, as well as the movement in translation of the slide 12.

 Still FIGS. 1 and 2, it can also be seen that the slide 12 is traversed, at a tapped hole 12b and substantially in its axis 10 of translation, by a screw 17 or anaLogue which comes, via a shoulder 27, bear against elastic means 2G, which are arranged in a housing 21 formed in the support pad 9. An elastic ring 26, or equivaLent, keeps the means 20 in their housing.

 Beyond its shoulder 27, the screw 17 is extended by a stud 37 or bulge which opens into a passage 31 arranged opposite in the bottom of the recess 21 this passage having a neck 32 so as to limit the movement of The screw 17 When it is unscrewed and thus secure the screw and the holding pad 9.

 With regard to the above-mentioned elastic means 20, it should be noted that they may comprise a series of elastic washers surrounding the part opposite the screw and which can be loaded in the axis 1C of application of the forces (see in particular FIG. 3) .

 Of course, any other type of suitable elastic means forming a compression spring could also be used.

 These elastic means, whatever their nature, serving, as we understand, as means for applying the force of bringing the parts together, their force or their load will be adapted so that in their compressed state they allow the application of the clamping force recommended by the manufacturer.

 Of course, the stroke of the slide 12 caused by the rotational maneuver of the part 14 will be adapted to cause a translation of the screw 17 allowing, during the tightening operation of the parts to place these elastic means 20 of their compressed state.

 Depending on the compression force to be achieved, around the extension of the screw 17, the lens 25 of suitable thickness will be adapted (see FIG. 3) which will be placed at the bottom of the housing 21, under the elastic means 20, so as to ensure a limitation of the end of travel of the screw, thus avoiding any false maneuver which could cause an excess of force on the parts 2, 3 or damage the means 20. The wedge 25 which may appear, for example, under the shape of a washer may have an orifice diameter smaller than that of the stud 37 of the screw, so as to constitute the neck 32 of limitation of translation to the aforementioned unscrewing.

 FIG. 3 also shows a possible embodiment of the shoe -9 at its bearing faces which come to bear against the part 3.

 In the example illustrated, the shoe 9 is in the general form of a multi-stage cone 9a, 9b, 9c allowing it to be able to be adapted to the connection socket considered whatever the internal diameter o of its barrel 13.

 Of course, in practice, the pad 9 which will be adapted on the end of the screw 17 will be shaped so that its bearing faces come to best adapt to the part of the part 3 intended to receive them. .

 If we now refer to Figure 4, we see a variant of the apparatus of the invention equipped to allow its operation by an operator placed outside the hole 29 at the bottom of which is disposed here the pipe 2 surmounted from its connection socket 3.

 To allow this maneuver "at a distance", the apparatus 1 is provided with a first extension 30 which extends along its axis the rod 4 and ends with an operating handle 30a comparable to the handle 11 of the embodiment illustrated in Figure 1.

 A second extension 31 extends substantially parallel. to the first 30 and is in the form of a circular cylindrical hollow tube or cane curved at its upper end, at 31a, to form a handle. This second extension is extended at its lower part by a lug 31b connected to the handle 15 of the part 14, thus making it possible to remotely control its rotation around the axis 10.

 Inside this second extension 31 and sensitively in the axis 10, extends a third ra L Longe 33 which, as for it, pro Longe upwards The head 17a of the screw 17 and allows its controlled operation in v # ssage / unscrewing.

 Preferably and corme is clearly seen in Figure 4, the guide flanges 34 make integral with one another The two extensions 30 and 31 facilitating their maneuver in rotation around their respective axes.

 The apparatus of the invention having been described in its structure, we will now present its operating mode, making for this reference to the apparatus illustrated in FIG. 1. Nevertheless, it is clear that the functioning of the apparatus " The extension illustrated in Figure 4 is identical.

 For the sake of clarity, we will treat, still by way of example, the case of an intervention aiming to heat seal a connection socket 3 to a pipe, above a pipe 2.

After the piece 3 has therefore been placed overlapping the piece 2, as illustrated in fig # ure 1, and the device 1 of the invention has been fitted with its suitable support pad 9 To the shape of the bearing surface of the part 3 intended to receive it, the lever 15 of the operating part 14 is placed in "rear" abutment, so that
The couLisseau 12 is at the top stop at the bottom of the thread (position illustrated in FIG. 1 and, in phantom, in FIG. 3).

At the same time, care was taken to unscrew, also at the bottom of the thread, screw 17, so as to match
The biggest adjustment margin.

 We can then pull the handle 11 (in the axis 14) by rotating it so as to energize the rod 4 and place the vee 5 of lower support under the pipe 2. The key 6 which engages in the notch opposite the rod makes it possible to maintain the angular position and the tightening tension reached which corresponds to the first force in approaching the two parts 2, 3, Lacquer L The force remains, in accordance with the invention, less than La clamping force that you ultimately want to achieve before welding.

These operations being carried out, we just screw
The screw 17 is approaching, so as to reduce the preset final tightening stroke which the same screw will move when the lever 15 is rotated.

 The elastic means 20 for applying the additional clamping force are then slightly under tension.

 To reach the desired tightening tension, it suffices to pivot the lever 15 from its "rear" stop marked D in FIG. 3, towards its "front" stop F, which causes, as we understand, the proper movement in transLation of the screw 17 and therefore the desired compression of the elastic means 20, which then develop the additional effort adapted to the tightening of the parts 2, 3 recommended by the manufacturer.

 The welding or heat sealing operation can then be carried out under the best conditions. This is done, and after the necessary cooling time has been respected, the device 1 can be removed by pivoting the lever 15 back, unscrewing the screw 17 and releasing the tension from the rod. 4 while pivoting it about its axis 14 so as to release the tab 5 from the underside of the pipe.

 Of course, the apparatus of the invention is not strictly limited to the embodiments which have been more particularly envisaged.

 In particular, a cam operating system could also have been used to ensure the final compression of the elastic means 20.

 With regard to the application of the clamping force, it will also be noted that support means 5, 9 shaped to apply to the parts 2, 3 a force distributed at several points could also have been envisaged.

Claims (9)

R, EVENr: ATIONS  1. Apparatus for Maintaining in Close Contact One of the other of two parts, such as a pressurized gas pipe and a connection socket respectively, with a suitable clamping force, in particular in order to facilitate their welding, characterized in that, so as to ensure a determined clamping force of these two parts (2, 3) together, it comprises  - means (5, 9) for bearing against two substantially opposite sides of the two parts (2, 3)  - first clamping means (4, 6, 8, 17, 20) for exerting on said bearing means (5, 9) a closing force less than the determined clamping force which it is desired to achieve  - And, linked to said first means, second clamping means (12, 14, 17, 20) to exert, on these same support means (5, 9), an additional force also determined, so as to reach the force desired clamping of the two parts (2, 3) between them.  2. Apparatus according to claim 1 characterized in that said second clamping means comprise  - elastic compression means (20) linked to One (9) of the support means, to exert, in their compressed state, the desired clamping force,  - And means (12, 14, 17) for bringing and maintaining in their compressed state said elastic means (20).  3. Apparatus according to claim 1 or claim 2, characterized in that said first clamping means comprise  - a rod (4) towards one of the ends of which is mounted a support means (5) intended to come to bear against a side of the one (2) of the parts to be clamped  - And a connecting piece (8) mechanically connected to another support means (9) intended to come to bear against a side opposite the first city of the other piece (3) to be tightened with said connecting piece (8) which can slide , substantially parallel to the general direction (10) of application of the clamping force, along the said rod (4) to which it is linked by means of a pawl (6), or the like.  4. Apparatus according to claim 3 characterized in that said means for bringing and maintaining The elastic means (20) in their compressed state include  - a slide (12) mounted movable in relation to the connecting piece (8), substantially in The general axis (10) of application of the clamping force, and comprising a threaded part (12a)  - an operating part (14) comprising a threaded part (14a) coming to cooperate with said threaded part (12a) of the slide (12), said operating part (14) being rotatable around the above-mentioned axis (10) COLLAR TRANSLATION  a pin (16), or equivalent, fixedly mounted on the connecting niece (8) and extending, on one side, into a slot (22) formed in said couissor (12) and, on the other, in a groove (24) provided in said operating part (14), so as to limit the rotational movement of the latter and the displacement in transLation of the slide (12)  - And a screw (17), or the like, which extends in a thread (12b) through said slider (12) sensitively in its axis (10) of translation and comes, via a shoulder (27 ), bear against one end of said elastic means (20), which are arranged in a housing (21) formed in the corresponding support means (9).  5. Apparatus according to claim 4 characterized in that said support means (9) which receives the elastic means (20) comprises a part (25) forming a stop for The screw (17) or anaLogue.  6. Apparatus according to claim 4 or claim 5, characterized in that said screw (17) or analog comprises at one end a bulge (37) cooperating with a coL (32) formed on a fixed part of the support means (9) corresponding, so as to make soLidary in transLation Said screw (17) or anaLogue and Said support means (9).  7. Apparatus according to any one of claims 3 to 6, characterized in that the rod (4) is notched along a generator and is movable in rotation around the axis (14) of transLation of the piece of Link (8), so as to allow the engagement or disengagement of the notches and the lock (6) or the like.  8. Apparatus according to any one of claims 3 to 7 characterized in that it comprises  - a first extension (30) for the remote control of the rod (4)  - a second extension (31), in the form of a tube, extended by a tab (31b) for the remote control of The operating part (14)  - a third extension (33) extending to The interior of the second extension (31) for the remote control of the screw (17) or the like  - And at least one guiding piece (34) connecting between them The aforementioned first two extensions (30, 31).  9. Apparatus according to any one of claims 3 to 8, characterized in that the support means (9) which is linked to the part (8) of connection is interchangeabLe and comprises a support pad cone-shaped with several stages, one of the stages of which is adapted to engage with the part of the part (3) which receives it.