EP1554065A1

EP1554065A1 - Cooled mandrel for winding a strip product

Info

Publication number: EP1554065A1
Application number: EP03778444A
Authority: EP
Inventors: Dominique Tellier; Jean Perret
Original assignee: VAI Clecim SA
Current assignee: Clecim SAS
Priority date: 2002-10-23
Filing date: 2003-10-23
Publication date: 2005-07-20
Also published as: WO2004037456A8; US20060043231A1; WO2004037456A1; CN1319663C; KR101024746B1; CN1726102A; KR20050083815A; FR2846263A1; US7341218B2; FR2846263B1; AU2003285443A1; BR0306627A

Abstract

The invention relates to a cooled mandrel for winding a strip product. The inventive mandrel comprises an assembly of adjacent segments (2) which are mounted to slide radially on a central shaft (1) and which are each equipped with a cooling circuit (24, 24'). The aforementioned cooling circuit comprises two holes, namely an inlet (75) and an outlet (75'), which are each connected by means of a variable-length connector (7, 7') to a heat transfer fluid-feed (5) or -discharge (5') conduit respectively. According to the invention, the connectors (7, 7') corresponding to each segment (2) are connected to a dispensing part (6) which is disposed on a lateral surface (13') of the shaft (1). Moreover, the above-mentioned supply (5) and discharge (5') conduits, which are disposed inside the central shaft (1), open transversely onto said lateral surface (13') of the shaft.

Description

Cooled mandrel for winding a strip product

The subject of the invention is a cooled mandrel for winding a product in a strip, in coil, in particular a metal strip. The invention applies especially to the winding of a thin strip continuously cast but can be used, in general, for the winding in reel of any strip being at a high temperature, likely to disturb the operation of the chuck. In metallurgical installations, in particular for rolling or treating metal strips, it is often necessary, at the exit of one part of the installation, to wind the strip into a coil in order to transport it easily to another part of the facility or other place of treatment.

A winding machine is used for this, comprising a mandrel consisting of a cylindrical bar driven in rotation about its axis and provided with means for fixing the end of the strip which is thus wound in a coil on the cylindrical bar.

Generally, the winding bar has a variable diameter and can retract to allow removal of the coil after winding.

For this purpose, the mandrels usually used are of the type comprising a support shaft centered on an axis and associated with rotation drive means, and a plurality of circular segments together forming a substantially cylindrical surface and fixed on the central shaft. support with the possibility of radial displacement so as to allow the diameter variation of the cylindrical surface thus formed and on which the strip is wound.

To control the variation in diameter of the mandrel, a rack and pinion device is usually used, comprising a control part sliding axially on the central shaft and on which is provided, for each segment, at least one conical part cooperating with at least one conjugate inclined face formed on an inner face of the segment, which can thus deviate or approach the central shaft by longitudinal displacement of the control part under the action of '' an expansion rod slidably mounted axially in a bore of the central shaft.

For a correct operation of the mandrel, the various parts in relative movement must be able to move with minimum friction. A lubrication of the contact surfaces of the parts in relative motion is therefore provided for this purpose.

Until now, such mandrels have been used mainly in laminating plants and the residence time of a coil on a mandrel is then quite limited and does not exceed 5 to 6 minutes, for example. Even when the laminated strip is hot, such a residence time does not normally pose a thermal problem capable of disturbing the operation of the mandrel.

For some time, however, it has been sought to develop new techniques for continuously casting very thin strips and it may be advantageous to wind such a strip on a reel on a mandrel.

However, shortly after casting, the strip is still at a very high temperature and, on the other hand, the time of winding and, therefore, of stay of the coil on the mandrel can be long because it is linked to the casting speed which is obviously much slower than that encountered in rolling plants.

However, the mandrels usually used cannot withstand such heat transmission, due to the thermal effects, in particular stresses and expansions of the different parts, which risk disturbing the operation.

To solve this problem, the applicant company recently proposed to produce a mandrel whose surface winding can be cooled by circulation of a heat transfer fluid.

In such an arrangement, described in document FR-A-2,761,964, the external face of each segment consists of a relatively thick curved plate inside which is provided a cooling circuit having an inlet orifice and an outlet orifice connected respectively to a supply pipe and to a discharge pipe provided at least in part, inside the central shaft on which the segments are mounted. To allow expansion and constriction of the mandrel by sliding the segments radially, the fluid inlet and outlet ports are each connected, by a deformable connection, to a chamber, respectively of supply or discharge, in which leads the corresponding pipe.

In the arrangement of document FR-A-2,761,964, the supply and discharge chambers connected respectively to each segment are provided in a fluid box fixed to a front end of the central shaft which, usually, is mounted rotatable on a support frame and extends cantilevered from a rear end to which a rotational drive torque is applied. However, as has been indicated, the radial displacement of the segments for expanding or shrinking the mandrel is usually controlled by a tubular piece slidably mounted on the central shaft of the mandrel and the displacement of which, in one direction or in the the other is determined by an expansion control rod slidably mounted axially in a bore of the central shaft. The tubular part must therefore be connected to this control rod by a connecting part which passes in front of the front end of the central shaft and can move alternately in one direction or the other for controlling the expansion or of shrinking segments. However, the latter cannot move in the longitudinal direction and it is the same for the water box which, in the arrangement of the document FR-A-2,761 .964 is connected to each segment by deformable connectors whose length may vary radially. It is therefore necessary to provide, between this water box and the front end of the central shaft, a space allowing the movement of the connecting piece with the expansion rod and the supply and evacuation pipes arranged at the interior of the central shaft must therefore be connected to the corresponding chambers of the water box by deformable or sliding connection means.

I t is therefore quite difficult, in such d isposition, to seal the cooling circuit. In addition, the segments are extended beyond the front end of the central shaft so as to provide a housing in which the water box is placed, the latter being connected to the end of the central shaft by rods passing through the connecting piece to allow axial displacement. However, the deformable connection fittings between each segment and the water box exert on the latter, in the radial direction, significant forces and which are not always equal. In addition, in a metallurgical installation, in particular of continuous casting, the mandrel risks being subjected to shocks and the water box, thus placed at the end of the mandrel constitutes a fairly fragile member.

The object of the invention is to solve such problems, while retaining the advantages of the cooled mandrel i described in document FR-A-2,761,964, by virtue of a simpler arrangement of the cooling circuit allowing, in addition, better protect the supply and discharge members of the heat transfer fluid.

Furthermore, the invention facilitates the disassembly of the mandrel for maintenance and also makes it possible to ensure in a simple manner the lubrication of the various parts in relative movement. The invention therefore applies, in general, to a cooled mandrel for winding a strip product comprising a central shaft extending between a rear end connected to means for driving in rotation around an axis and a front end, and a set of adjacent segments slidably mounted radially on said shaft and having curved external faces which join to form a substantially cylindrical winding surface centered on the axis of the central shaft, means for controlling a variation in diameter of the winding surface, by radial sliding of said segments, between an expanded position and a constricted position, and means for cooling the surface of each segment by circulation of a heat transfer fluid comprising, for each segment, a cooling circuit formed inside said segment and having an inlet orifice and an outlet orifice for the heat transfer fluid connected ch no, via a deformable connection, to a pipe, respectively, for supplying or discharging the fluid. In accordance with the invention, each supply or evacuation pipe is formed, at least in part, inside the central shaft and is provided, near the front end of the latter, with 'a bent portion extending transversely to the longitudinal axis (X', X) of the central shaft and opening onto a lateral face of said shaft by a transverse orifice, respectively of supply or discharge, which is connected by sealingly, by at least one connector of variable length, to at least one orifice, respectively inlet or outlet, of at least one segment.

According to another particularly advantageous characteristic of the invention, the connection fittings with the inlet and outlet orifices of each segment are fixed to a distribution piece in the form of a ring having a concave internal face threaded tightly over a span smooth of the lateral face of the central shaft, on which are formed at least two internal orifices which, in the threaded position of the distribution piece, are each aligned with a transverse orifice, respectively for supply or discharge, s opening on said bearing surface of the central shaft, so as to produce a substantially sealed connection, and an external face on which are formed, for each segment, two external orifices, respectively of supply and evacuation, each associated with a means of connection of a connection fitting with an orifice, respectively of entry or exit of the corresponding segment, each external orifice, respectively of supply or evacuation being connected to an internal orifice, respectively of supply or of evacuation, through at least one channel, at least in part, into the distribution part.

In a preferred embodiment, the mandrel comprises for each segment, a pair of pipes, respectively supply and evacuation, formed inside the central shaft and opening respectively, on the smooth bearing of the shaft , by a pair of transverse orifices, the two external orifices, respectively of supply and discharge, corresponding to each segment are connected by two channels formed in the distribution piece, to two internal orifices, respectively of supply and of 'evacuation, and the pairs of internal orifices corresponding to the different segments are distributed along the internal face of the distribution piece, in the same way as the pairs of transverse orifices on the smooth bearing of the shaft, such that, in the threaded position of the dispensing part, each internal orifice, respectively of supply or evacuation, is in the extension of a transverse orifice al connected to a line, respectively supply or discharge, of the central shaft. The mandrel comprising a number (n) of segments centered on radial planes distributed in a star around the axis, the central shaft is therefore provided with (n) pairs of pipes, respectively supply and discharge, s' extending symmetrically on either side of each radial median plane and each opening into the smooth bearing of the shaft by a transverse orifice having an axis parallel to said radial median plane and the internal and external orifices of the distribution piece are distributed by pairs symmetrical with respect to the radial median plane of each segment and have axes parallel to said radial median plane and aligned with the axes of each corresponding pair of transverse orifices of the smooth bearing of the central shaft.

In a particularly advantageous manner, the smooth bearing surface of the central shaft and the combined internal face of the distribution part have the form of cylinders of revolution centered on the axis of the central shaft and having the same diameter, at the mounting clearance close, the distribution part being slid over the smooth bearing of the shaft with the interposition of at least two circular seals on either side of the aligned orifices.

In this case, the external face of the distribution piece preferably comprises a plurality of connection facets, in number equal to the number (n) of segments, each provided with a pair of external orifices, respectively supplying and discharge, connected to a pair of orifices, respectively of entry and exit, of the corresponding segment, by a pair of connectors of variable length each having an internal end and an external end fixed, respectively, on a facet of the distribution part and on a connection facet of the segment on which the inlet and outlet openings for the fluid are formed. Each connector of variable length can advantageously consist of a tube made of a deformable material such as an elastomer.

In a manner known per se, the radial sliding of the segments is controlled by a rack and pinion device comprising a tubular sheath mounted to slide axially on the central shaft between two positions, respectively moved back and forward, and connected to a control rod mounted to slide in a axial bore of said shaft, by a connecting member extending transversely in front of the front end of the central shaft.

According to another particularly advantageous characteristic of the invention, the tubular sheath on which the inclined faces for controlling the radial sliding of the segments are arranged extends substantially, in its advanced position, up to the level of the nesting range of the dispensing piece, and is extended above it, by at least two arms each passing between two pairs of connecting fittings between the dispensing piece and the two corresponding adjacent segments, so as to be fixed, by a front end, on the transverse member for connection with the sliding control rod.

The mandrel comprising (n) segments surrounding the central shaft, the distribution piece itself comprises (n) lateral facets for sealed connection, each of a pair of connection fittings, between which are (n) faces of sliding each forming a sliding support on a control arm of the tubular sheath. Preferably, the external face of the dispensing part has a substantially polygonal shape, the lateral connection facets of the connectors being planar.

According to another preferred characteristic, the transverse connecting member between the control rod and the sheath consists of a solid part, provided with a central recess which, at least in a rear position of the control rod, comes to thread on a centering surface, formed between the front end of the central shaft and the interlocking surface of the distribution piece. In certain cases, the connecting member can advantageously be extended, towards the front, by a projecting part forming a rocket centered on the axis of the central shaft and capable of bearing, by means of a landing, on a fixed part. Thus, instead of extending cantilevered from the support frame, the central shaft can bear, by removable means, on a fixed part, which prevents bending of the central shaft and to guarantee a good winding of the turns on each other.

On the other hand, the use, according to the invention, of a tubular sheath connected to the transverse connecting member with the sliding control rod by arms passing between the connecting fittings, allows the establishment of '' a very simple lubrication system for moving parts.

In fact, according to a particularly advantageous arrangement, the mandrel comprises a lubrication circuit, at least, inclined faces for controlling the sliding of the segments comprising, for each inclined face, at least one grease outlet orifice, placed at the outlet of a pipe extending along the sheath and extended along at least one sliding control arm to a supply orifice, placed on the front end of said arm and coming to be connected, by fixing the connecting member on said arm, on a sealed connection tube, carried by the connecting member, and connected to a means for introducing grease pressure.

Preferably, each connection pipe of the lubrication circuit is formed on a rear face of the connecting member, on which the front end of the corresponding control arm of the sleeve is applied and is placed at the outlet of a conduit. extending, at least in part, inside the connecting member, up to a grease introduction orifice.

To ensure a tight supply to the lubrication circuit, even under high pressure, the front end of the control rod which is centered on the axis of the mandrel is provided with a cylindrical seat which fits into a formed conjugate bore in the center of the connecting piece and into which opens at least one grease inlet orifice connected by a pipe to a connection pipe carried by the connecting piece, and the control rod is provided with at least one pipe s 'extending longitudinally between a rear orifice connected by the grease introduction means and a front orifice formed on the fitting surface of the control rod, and placed in communication with the grease inlet orifice opening into the bore of the connecting piece, after fitting therein the control rod.

Advantageously, the engagement surface of the control rod is provided with at least one annular groove which, in the fitted position of the control rod, is at the level of the grease introduction orifice opening onto the central bore, said groove being framed by two annular seals ensuring the tightness of the connection thus formed. The invention also has other advantages and covers other characteristics, mentioned in the claims, which will appear during the following description of a particular embodiment, given by way of example and illustrated by the appended drawings. Figure 1 shows two half-views in longitudinal section of the mandrel according to the invention, respectively in the expanded position at the top and in the constricted position at the bottom. Figure 2 shows two half-views in horizontal section along the line II-II of Figure 1, respectively in the expanded and constricted position.

FIG. 3 shows two half-views in cross section along the line l ll-ll l of FIG. 1.

FIG. 4 is a partial half-view of the front end of the mandrel in longitudinal section along the line IV-IV of FIG. 5.

Figure 5 is a cross-sectional view along the line V-V of Figure 4, in the constricted position at the top and in the expanded position at the bottom.

Figure 6 is another partial view of the front end of the mandrel, in longitudinal section along the line VI-VI of Figure 5. Figure 7 is a partial view, in longitudinal section, along VII-VII of Figure 8 , from the rear end of the central shaft.

Figure 8 is a cross-sectional view along line VIII-VIII of Figure 7. Figure 9 shows two partial half-views, in longitudinal section, of the front end of the mandrel.

Figure 10 is a front view of the connecting piece.

Figure 1 1 is a partial view, from above, of the tubular control part. Figure 12 shows two half-views in cross section along the line XII-XI I of Figure 1, respectively in the expanded and constricted position.

Figure 13 is a partial view, in longitudinal section, of a variant of the front end of the mandrel. As indicated, the mandrel according to the invention generally comprises a central shaft 1 rotatably mounted on a frame 10 around two bearings 1 1 and surrounded by a set of segments 2 slidably mounted radially on the central shaft and having curved external faces which join tangentially to form a surface cylindrical winding centered on the axis X'X of the shaft; the radial sliding of the segments is controlled by a tubular piece in the form of a sheath 3, threaded on the central shaft and provided with inclined faces 31 which cooperate with corresponding inclined faces 21 of each segment 2 to determine the expansion or the constriction of the mandrel by longitudinal displacement of the tubular sheath 3 between two positions, respectively moved back and advanced, under the action of an expansion control rod 4 sliding in an axial bore of the central shaft 1 and connected to the tubular part 3 by a transverse connecting member 40.

All these provisions are well known and do not require a detailed description. This is why, the drawings only show, in FIG. 1, the front part of the shaft 1 carrying the segments 2 and, in FIG. 7, the rear part of the shaft 1 with which there are associated means of rotational drive not shown in the drawing and a cylinder 41 for controlling the axial sliding of the expansion rod 4. Furthermore, the mandrel is of the type described in the preceding patent FR-B-2,761 .964, comprising means for cooling of the winding surface by circulating a heat transfer fluid inside each segment. To this end, each segment 2 therefore comprises a curved external wall 20, relatively thick, inside which is formed a cooling circuit 24, 24 'comprising an inlet orifice 75 and an outlet orifice 75' connected respectively, by connectors of variable length 7, 7 ′, to supply lines 5 and discharge lines 5 ′ arranged inside the central shaft.

Advantageously, each connector of variable length 7, 7 'consists of a tubular sleeve of deformable material such as an elastomer, but one could also use a telescopic assembly. As we saw above, in the previously known arrangement, the deformable fittings were connected to a distribution box placed in front of the front end of the central shaft and separated from it by a space allowing the longitudinal movement of the connecting member, each segment being extended beyond the front end of the central shaft so as to provide a housing in which the distribution box was placed.

In the arrangement according to the invention, on the contrary, the fluid distribution box 6 is threaded on the shaft 1 and comprises a set of channels 65, 65 'placed in alignment with channels 52, 52', formed radially in the thickness of the central shaft 1 and each opening, on the lateral face 13 thereof, by an orifice, respectively of supply 53 or discharge 53 ', said channels 65, 65' being connected, by deformable connections 7, 7 'with the orifices, respectively of inlet 75 or outlet 75', of the corresponding segment. This distribution box 6 is therefore placed behind the connecting member 40 which can move freely under the action of the expansion control rod and the segments 2 extend over a length substantially equal to that of the 'central tree.

In particular, in the preferred embodiment shown, in Figures 4 and 5, the central shaft 1 is provided, for each segment 2, with two bores parallel to the axis, which extend over the entire length of the 'shaft 1 and respectively constitute a supply line 5 and a discharge line 5' arranged symmetrically on either side of the median plane P of the segment 2. In the case, shown in the figure, of a mandrel comprising four segments each covering a quadrant, the central shaft 1 is therefore provided with four pairs of pipes 5, 5 '.

As before, the connecting member 40 which is fixed on the front end of the expansion control rod 4 extends transversely in front of the front face 12 of the shaft central 1. However, in the previous arrangement of French patent 2,761,964, the supply and exhaust pipes provided in the central shaft had to be extended by pipes passing through the connecting member, in order to connect to the distribution box placed in front of it. In the arrangement according to the invention, on the contrary, the longitudinal bores constituting the pipes 5, 5 'are closed, each by a plug 51, at the front face 12, and communicate with a channel 52, 52' which s 'extends transversely to the axis X'X of the mandrel to open out through an orifice 53, 53' opening onto a front part 13 'of the lateral face 13 of the shaft 1.

In the preferred embodiment shown in the figures, the lateral face 13 of the shaft 1 on which is threaded the control part 3 in the form of a tubular sheath is provided, on its front part 1 3 ′, with a smooth bearing having a cylindrical section of revolution and on which is threaded a distribution piece in the form of a ring 6 having a concave internal face 61 of diameter equal, apart from the mounting clearance, to that of this smooth bearing 13 '.

On the other hand, the distribution piece 6 is limited by an external face 62 comprising, for each segment 2, a facet, preferably planar, for fixing the deformable connection fittings between the segment 2 and the supply lines 5 and evacuation 5 '. In the four-segment embodiment shown in the figures, the external face 62 of the distribution piece 6 therefore has a square section so as to present four planar connection facets, each of a pair of deformable connectors 7, 7 . For each segment 2, the distribution ring 6 is provided, on its internal face 61, with two internal orifices 63, 63 'which each communicate with an external orifice 64, 64' formed on the external face 62, by a channel 65, 65 'drilled in the thickness of the ring 6. In addition, as shown in Figure 5, these channels 65, 65 'connecting between the internal orifices 63, 63' and external 64, 64 'are centered on axes orthogonal to the axis X'X of the shaft 1 and parallel to the median plane P of the corresponding segment 2 and are aligned, in the threaded position of the ring 6, with the axes of the channels 52, 52 'which i pass through the shaft 1 to communicate with the supply line, respectively 5 or 5 'discharge.

Preferably, the smooth bearing surface 13 ′ formed on the front part of the shaft 1 has a diameter smaller than that of the lateral face 13 of the latter so as to form a countersink allowing the fitting of the distribution piece 6 in ring shape, up to a determined position for which the channels 52, 52 'of the shaft 1 and 65, 65' of the ring 6 are perfectly aligned, the ring 6 being held in this position by a stop 15.

On the other hand, each external orifice 64, 64 'of the ring 6 opens into a deformable connection 7, 7' fixed by a pierced plate forming an internal flange 71 on a corresponding facet 62 'of the external face 62 of the ring. Similarly, at their opposite end, the two connections 7, 7 'are fixed by an external flange 71' on a flat facet 73 formed on the internal side of a connection piece 70 in the form of a circular sector fixed to the end before each segment 2.

Advantageously, an intermediate plate 72 is interposed between the external flange 71 'and the connection piece 70 of the segment so as to facilitate the disassembly of the segment, as will be seen below. As usual, each segment 2 comprises an external part 20 in the form of a cylindrical sector of revolution which constitutes a part of the winding surface of the strip and an internal part 20 ′ on which the inclined faces 21 cooperating with are formed. the mating faces 31 of the tubular sheath 3 to control the expansion or the constriction of the mandrel.

In the preferred embodiment shown in the figures, the external part 20 of segment 2 consists of a curved plate in the thickness of which are formed two series of channels, respectively 24, 24 'parallel to the axis X' X of the mandrel and extending, respectively, on either side of the median plane P of the segment, said channels being regularly spaced apart so as to cover substantially the entire surface of the segment.

As shown in FIG. 4, the front end of segment 2 is provided with two circular grooves 25, 25 'into which the two series of channels 24, 24' open, respectively. On the other hand, the connection piece 70 which is fixed, as we have seen, on the front end of the curved plate 20, is itself provided with two oblong holes 74, 74 'which each open , on one side on a part of the corresponding groove 25, 25 'of segment 2 and on the other, in a channel 76 formed in the thickness of the connection piece 70 and opening out through an orifice 75, 75' on the planar facet 73 for applying the external flange 71 'for fixing the pair of connectors 7, 7'.

In addition, as shown in Figure 1, the rear end of each curved plate 20 is provided with a circular groove 23 which connects the two series of channels 24, 24 'and is closed to the outside by a plug .

Conventionally, the shaft is provided with a transverse flange 14 engaging in a housing formed at the rear of each segment 2 which is held by an axial stop 27 with a possibility of radial sliding. The two orifices 75, 75 'formed in the connection piece 70 therefore remain aligned with the transverse channels 52, 52' to which they are connected by the deformable connectors 7, 7 'which follow the movements of expansion or constriction of the segment. The fitting of the ring 6 on the smooth surface 13 'with a simple mounting clearance ensures a tight connection between the channels 52, 52' and 65, 65 ', annular seals 16 making it possible to avoid leaks from inside the mandrel.

Thus, the heat transfer fluid arriving through the supply line 5 passes successively through the channel 52, the deformable connector 7 and the inlet orifice 75, to emerge through the oblong hole 74 in the groove 25 so as to spread in all of the channels 24. At the rear end of the segment 2, the fluid passes through the rear groove 23 to return via the discharge channels 24 'and then passes through the oblong hole 74', the outlet orifice 75 ', the deformable connector 7' and the channel 65 'to lead into the discharge pipe 5'.

The ring 6 thus forms a fluid distribution box, by means of the deformable connections 7, 7 ', between each segment 2 and the pipes, respectively of supply 5 and discharge 5', formed in the central shaft. 1.

Thanks to the invention, this distribution box 6, threaded on the front part of the central shaft 1 and placed behind the connecting member 40, is perfectly protected against possible shocks. It is necessary, however, to ensure the connection between this connecting member 40 and the control part 3 of the expansion and the constriction of the segments which consists, as usual, of a tubular sheath threaded on the cylindrical lateral face 13 of the 'shaft 1 and whose length is limited so as to extend only up to the level of the bearing surface 13' of fitting of the distribution ring 6, in the advanced position of the sleeve corresponding to the constriction of the segments.

To this end, according to another particularly advantageous characteristic of the invention, the tubular sheath 3 for controlling the expansion and shrinking of the segments extends, in its advanced position, to the level of the bearing surface 13 ′ for fitting the distribution ring 6, and is extended forward, beyond this by at least two arms 32 which each pass in a space left between two pairs of deformable connectors 7, 7 'and each extend to the level of the front end 15 of the shaft 1, so that the connecting member 40 with the rod expansion control 4 can be fixed, by bolts 34, on the front face 33 of said arms 32 (Figure 2). Thus, as shown in FIG. 5, in the four-segment embodiment, the tubular sheath 3 is extended by four connecting arms 32 arranged in a star and each centered on a plane P 'of junction between two adjacent segments, so to pass between the deformable fittings 7, 7 'corresponding to each segment.

Preferably, the connecting member 40 consists of a relatively massive bell-shaped part comprising a central recess 42 which, at least in a rear position of the control rod 4 corresponding to the expansion of the mandrel, comes s 'thread on a centering surface formed between the front end 12 of the central shaft and the distribution ring 6. As shown in the figures, this centering surface 15' can advantageously be constituted by the lateral face of the flange 15 of the distribution ring 6.

The central part 43 of the connecting member 40, which constitutes the bottom of the recess 42, is pierced with a bore 44 in which the end 44 'of the control rod 4 is threaded, the latter being extended by a bolt 45 fitted with a tightening nut.

Thus, the rod 4 sliding axially in the central shaft 1 and connected to the tubular sheath 3 by the transverse connecting member 40 and the arms 32 can control the expansion or the constriction of the mandrel by radial displacement of the segments 2. As we indicated, the whole system of distribution of the heat transfer fluid in the different segments, placed between the front end of the segments 2 and the solid part 40 constituting the connecting member with the control rod 4 is perfectly protected against shocks. In addition, all the organs of the fluid circulation circuit are axially integral with the central shaft 1 and can be fixed in leaktight manner, either on the latter or on the various segments 2 by means of the deformable connectors 7 , 7 '. This arrangement therefore ensures the distribution of the heat transfer fluid in the various segments with perfect sealing and without the use of hoses.

Indeed, as shown in Figures 3 and 5 relating to a four-segment assembly, the central shaft 1 can be pierced, over its entire length, with eight longitudinal bores distributed regularly around the axis and arranged in pairs so to constitute, for each segment, a supply channel 5 and an evacuation channel 5 'extending symmetrically on either side of the median plane P of the segment and each communicating, by a transverse channel 52, 52' with a deformable connection 7, 7 'for connection with an orifice, respectively of inlet or outlet of the fluid, formed on the connection piece 70 of each segment.

As indicated in FIGS. 7 and 8, the supply and the evacuation of the heat transfer fluid can be ensured, in a manner analogous to that which had been described in the previous patent n ° 2 761 964, by a rotary joint 54 constituted of a sleeve-shaped part threaded onto the rear part of the shaft 1 and comprising, on its internal face, two circular grooves connected respectively to means for supplying and discharging the fluid and communicating, by transverse tubes 55, 55 ', with the bores constituting, respectively, the supply 5 and discharge 5' channels.

However, the arrangement according to the invention also has other advantages. First of all, since the fluid distribution system is placed behind the connecting member 40, it is possible to arrange the front end of the central shaft 1 of the mandrel so as to allow support transverse thereof on a fixed part.

Indeed, as shown in Figure 13, the part 40 constituting the transverse connecting member can be extended forward by a projecting central portion 43 ', forming a kind of rocket on which can be threaded a bearing 17 by which the shaft 1, which rotates about its axis, can bear on a fixed part, not shown.

It is thus possible to avoid bending of the shaft under the weight of the coil and, thus, to ensure the contiguous winding of the superimposed turns. However, if the weight of the wound reel, as well as the tension applied to the strip, are not excessive, the mandrel shaft can, as usual, extend overhang from the support frame 10. In in this case, it is advantageous to cover the front end of the mandrel with a protective cover 26 removably attached to the connecting member 40 and extending rearward so as to cover all of said connecting member 40. Likewise, each segment 2 can be extended forward by a curved plate 26 ′ having a diameter slightly smaller than that of the cover 26 so as to penetrate inside the latter with the possibility of longitudinal sliding on the length corresponding to the axial displacement of the expansion control rod 4. A substantially continuous protective cover is thus produced against dust or other external nuisances, making it possible to avoid pollution of the interior of the mand rin.

However, the invention also makes it possible to ensure simple and effective lubrication of the different parts of the mandrel. It is necessary, in fact, to lubricate the parts in contact and, in particular, the conjugate inclined faces 31, 21 which ensure the expansion and the constriction of the mandrel. To this end, each inclined face 31 of the sleeve 3 is provided with a grease outlet orifice 80 which, thanks to the invention, can be connected, via the connecting member 40, to at least one channel 8 formed over the entire length of the expansion rod 4 and connected to a grease supply means 48, fixed to the rear part of the mandrel. As shown in particular in FIG. 1, each grease outlet orifice 80 is placed at the outlet of a pipe, at least part of which is pierced inside the tubular sheath and can be extended outside of the latter. , by a pipe 81 extending along the sheath and sealingly connecting to a channel 82 pierced inside a connecting arm 32 (Figure 6) and opening, on the front face 33 of said arm, by an orifice 83 which, after fixing the connecting member 40 on the arms 32 by means of the bolts 34, is connected in leaktight manner to a tube 83 'formed on the connecting piece 40 and opening onto the rear face of that -this .

As shown in Figures 9 and 10, this tubing 83 'is connected by a channel 84 extending radially inside the connecting member 40, to a grease introduction orifice 85 opening on the face internal of the axial bore 44 into which is fitted the front end of the expansion rod 4 which forms a cylindrical surface 44 'on which is formed a circular groove 46 which communicates, by a transverse channel, with the channel supply 8 arranged inside the expansion rod 4.

As indicated, the central bore 44 of the connecting member 40 constitutes a countersink making it possible to block the connecting member 40 in a fixed position for which the orifice 85 for introducing grease, opening on the bore 44, is at the level of the groove 46. This groove 46 is framed by two annular seals so as to ensure a sealed pressure connection between the supply channel 8 and the orifice 85 for introducing grease. In known manner, as shown schematically in Figure 7, the rear end of the control rod 4 is connected to the rod of the cylinder 41 for controlling expansion or constriction of the mandrel, by a coupling member 47 which ensures in addition, a sealed connection, by a circuit not shown, with a means 48 for supplying grease under pressure secured to the jack 41.

Thus, the grease introduced by the pipe 8 pierced in the control rod 4 successively passes through the connecting member 40 and one of the arms 32 of the sheath to open into at least one orifice 80 formed on at least one inclined face 31.

To control a radial displacement, parallel to itself, of each segment, the tubular sheath 3 comprises at least two series of inclined faces 31 centered respectively on two transverse mean planes spaced apart longitudinally and cooperating with at least two series of inclined faces 21 formed on the inner side of segment 2.

For example, in the case shown in the figures, the sheath 3 and the segments 2 have three series of inclined faces 31, 21 spaced apart longitudinally. The arrangements according to the invention allow the distribution of the fat, from a same axial channel 8, over all of the inclined faces 31. In fact, as shown in FIGS. 9 and 10, a groove 46 communicating with the channel 8 can supply several orifices 85 opening onto the internal face of the bore 44 and each connected, by a channel 84, to a channel 82 passing through a arm 32 and extended by a pipe 81 which may consist in part of an external pipe extending along the external face of the sleeve 3, between the projecting parts 30 carrying the inclined faces 31. This piping 81 advantageously opens into a bifurcation placed at the mean plane of a series of inclined faces to divide into at least two branches 86 each connected to an outlet orifice 80 formed on one or other of the inclined faces 31 of this series. Each arm 32 can optionally be pierced with several channels 82 and, for example, if the sheath 3 is provided with four arms 32 as shown in the figures, it is easy to distribute a sufficient number of supply lines over the sheath 3 so as to supply grease to all the inclined faces 31 for controlling the expansion or shrinking of the mandrel.

In addition, as shown in the figures, other pipes 87 connected to the longitudinal channel 82 can also be provided in the connecting member 40 or the tubular sheath 3 in order to lubricate other parts of the mandrel.

The arrangement according to the invention also makes it possible to implement a centralized lubrication system for the different parts of the mandrel. To this end, in the preferred embodiment shown in the figures, the control rod 4 is provided with two axial channels 8, 8 'which communicate respectively with two grooves 46, 46' formed on the cylindrical surface 44 'of the front end of the rod. As shown in FIG. 10, the two grooves 46, 46 'can supply, respectively, two groups of channels 84, 84' which are connected in pairs to distributors 89 making it possible to supply one or the other of two groups pipes 82, 81, 81 'formed in the arms 32 or along the tubular sheath 3 and connected to some of the inclined faces 31 of the sheath 3, these being thus divided into two groups which can be supplied alternately, thanks to a system central lubrication, from one or other of the supply channels 8, 8 ', passing through the control rod 4. It should be noted that the lubrication circuits can be produced almost entirely by holes made in machined parts and that the fittings are eliminated. In fact, in the embodiment shown in the drawings, only the rigid pipes 81, 86 extend outside of the sleeve 3, no hose being necessary to allow the sleeve and the segments to slide.

However, another important advantage of the invention still lies in the fact that the entire mandrel can be easily disassembled for maintenance or replacement of certain parts.

It should be noted, in fact, that the cooling segments 2, which are in contact with the strip to be wound, constitute a kind of wearing part, even if they are designed to hold as long as possible. For this reason, it is advantageous to be able to replace them without dismantling the entire mandrel.

For this, as indicated above, the external flange 71 'of each pair of deformable fittings 7, 7' is fixed to an intermediate plate 72 which, itself is fixed to the connection piece 70 of segment 2 by retaining screws 76 which can be removed from the outside. The external part 20 of each segment 2 can thus be removed and replaced, leaving in place all the other parts of the mandrel, and in particular, the distribution ring 6 and the deformable fittings 7, 7 '.

But it is also possible to change the deformable connections, which are made of a flexible material of the elastomer type, without having to dismantle the mandrel. For this, it suffices to remove the front cover 26 and to unscrew the bolts 45, 34, for fixing the connecting member 40, respectively on the control rod 4 and on the arms 32, to remove the member link 40 and access the distribution box 6 which can thus be dismantled as a block with the four pairs of deformable connectors 7, 7 ′ and the plates 72. In this regard, the machining carried out at the four corners of the ring 6 makes it possible to ensure that it is held with guidance between the four arms 32 of the sleeve 3 during disassembly, the latter being carried out in the constricted position of the mandrel. In this way, after having been released from the spindle 13 ', the water box 6 remains held between the arms 32 of the sleeve 3. On the other hand, on reassembly, the mandrel is expanded and it is the connecting member 40 with the support ring 15 which pushes the water box 6 on the smooth surface 13 ', to the bottom of the counterbore, in a determined position for which the orifices of the water circulation circuits are aligned.

The assembly of the distribution box 6 and the deformable connections 7, 7 ′ with the intermediate plates 72 therefore constitutes a complete mechanical sub-assembly, removable in situ after having simply removed the connecting member 40. It can thus be replaced a deformable connection without having to deposit the mandrel entirely.

However, the arrangements according to the invention also allow easy disassembly of the entire mandrel, in a single operation.

For this, it suffices, in fact, to remove the axial stops 27 which, as we have seen, axially secure the segments 2 with the flange 14 of the shaft 1, with the possibility of radial sliding.

After removing the front cover 26 and unscrewing the nut connecting the expansion rod 4 to the connecting member 40, it is possible to dismantle the entire mandrel, in the constricted position, by driving the water box 6 which is enclosed inside the arms 32 of the sheath 3.

Of course, the invention is not limited to the details of the embodiment which has just been described by way of simple example and could be subject to variants using equivalent means, while remaining within the protective framework defined by the revendications. For example, the mandrel could have a different number of segments.

On the other hand, to produce the cooling circuits, it is advantageous for each segment 2 to have a wall thick enough to pierce therein two series of fluid circulation channels. However, each segment could also be produced in mechanically welded construction, in the manner described in the previous patent No. 2,761,964, the outer wall of the segment comprising two curved plates, respectively internal and external, separated from one of the other so as to provide a free space iv ivise, by at least one partition parallel to the axis, in at least two chambers, respectively of supply and evacuation which open respectively in an inlet orifice and an outlet orifice heat transfer fluid opening on a connection facet formed on the internal face of the segment, at one end thereof, and to which two deformable connectors 7, 7 ′ can be connected. However, the preferred embodiment described above makes it possible to better resist the high thermal stresses to which the segments are subjected.

In particular, as shown in FIGS. 1 and 12, the curved plate 20 constituting the external part of the segment in which the channels 24, 24 ′ are formed, can be fixed on the internal part 20 ′ on which the inclined faces 21 are formed, by a series of screws 28 placed in the median axis of the segment and associated with keys 28 'which engage in corresponding housings of the two parts 20, 20' of the segment, in order to transmit the belt tension torque, with longitudinal play allowing the segment to expand.

In addition, the realization of the cooling circuits by bores which can be placed relatively close to the external surface, makes it possible to precisely regulate the extracted heat flow by varying the water flow rate. It should also be noted that, if it is particularly advantageous to carry out centralized lubrication in the manner described above, the mandrel could also, in a simpler design, be lubricated manually. In this case, it would no longer be necessary to provide supply channels 8, 8 ′ in the expansion rod 4 but the connecting member 40 would still be produced as a bored block allowing the distribution of the fat by the arms 32 for connecting the sheath, the distributors 89 being simply replaced by individual greasing bars which can be accessed by a simple modification of the front cover 26.

The reference signs inserted after the technical characteristics mentioned in the claims are for the sole purpose of facilitating the understanding of the latter and in no way limit their scope.

Claims

1. Cooled mandrel for winding a strip product, comprising a central shaft (1) extending between a rear end connected to means for driving in rotation about an axis (X'X) and a front end , and a set of adjacent segments (2) mounted to slide radially on said shaft (1) and having curved external faces which connect to form a substantially cylindrical winding surface centered on the axis (X'X) of l central shaft (1), means (3,4) for controlling a variation in diameter of the winding surface, by radial sliding of said segments (2), between an expanded position and a constricted position, and means for cooling the surface of each segment by circulation of a heat transfer fluid comprising, for each segment, a cooling circuit (24, 24 ') formed inside said segment (2) and having an inlet orifice ( 75) and an outlet (75 ') of the heat transfer fluid re each connected, via a variable length connector (7,7 '), to a line (5) or discharge (5') of the fluid, respectively, characterized in that each line, respectively supply (5) or evacuation (5 ') is arranged, at least in part, inside the central shaft (1) and provided, near the front end of that -this, of a bent part (52, 52 ') extending transversely to the longitudinal axis (X'X) and opening onto a lateral face (13') of said shaft (1) by a transverse orifice, respectively d 'supply (53) or discharge (53'), which is tightly connected, by at least one connector of variable length (7, 7 '), to at least one orifice, respectively inlet (75) or outlet (75 '), of at least one segment (2).

2. Winding mandrel according to claim 1, characterized in that the connectors of variable length (7, 7 ') connecting with the inlet (75) and outlet (75') orifices of each segment (2) are fixed to a distribution piece (6) in the form of a ring having a concave internal face ( 61) threaded tightly on a smooth surface (13 ') of the lateral face (13) of the central shaft (1), on which are formed at least two internal orifices (63, 63') which, in the position threaded from the distribution piece (6), are each aligned with a transverse orifice, respectively supply (53) or discharge (53 '), opening on said bearing surface (13') of the central shaft ( 1), so as to produce a substantially sealed connection, and an external face (62) on which are formed, for each segment, two external orifices, respectively of supply (64) and evacuation (64 '), each associated a means (71) for connecting a connection fitting (7) to an orifice, respectively inlet (75) or outlet (75 ') of the corresponding segment, each gold external ifice, respectively of supply (53) or discharge (53 ') being connected to an internal orifice, respectively of supply (63) or discharge (63'), by at least one channel (65) formed , at least in part, in the distribution part (6).

3. winding mandrel according to claim 2, characterized in that it comprises, for each segment (2), a pair of pipes, respectively supply (5) and discharge (5 '), arranged at the interior of the central shaft (1) and opening respectively, on the lateral face (13) of the shaft (1), by a pair of transverse orifices (53, 53 '), that each pair of external orifices, respectively supply (64) and evacuation (64 '), corresponding to a segment is connected by two channels (65, 65') formed in the distribution piece (6), to a pair of orifices internal, respectively supply (63) and discharge (63 '), and that the pairs of internal orifices (63, 63') corresponding to the different segments are distributed along the internal face (61) of the distribution part (6), in the same way as the pairs of transverse holes (53, 53 ') on the nesting surface (13') of the shaft (1), so that, in the threaded position of the distribution piece (6), each hole internal, respectively supply (63) or evacuation (63 '), is in the extension of a transverse orifice (53, 53') connected to a pipe, respectively supply (5) or evacuation (5 '), from the central shaft (1).

4. winding mandrel according to claim 3, comprising a number (n) of segments (2) having a radial median plane (P) and extending between two radial junction planes, said radial planes being distributed in a star around the axis (X'X), characterized in that the central shaft (1) is provided with (n) pairs of pipes, respectively supply (5) and discharge (5 '), extending symmetrically on either side of each radial median plane P and each opening into the lateral face (13) of the shaft (1) by a transverse orifice (53, 53 ') having an axis parallel to said radial median plane (P ) and that the internal (63, 63 ') and external (64, 64') orifices of the distribution piece (6) are distributed in pairs symmetrical with respect to the radial median plane (P) of each segment and have parallel axes to said radial median plane and aligned with the axes of each corresponding pair of transverse orifices (53, 53 ') of the interlocking surface (13 ') of the central shaft (1).

5. Winding mandrel according to one of claims 2, 3, 4 characterized in that the lateral face (13) of the central shaft and the conjugate internal face (61) of the distribution piece (6) have the shape of cylinders of revolution centered on the axis (X'X) of the central shaft (1) and having the same diameter, apart from the mounting clearance, and that the distribution piece (6) is threaded by sliding on the engagement surface (13 ') of the shaft (1) with the interposition of at least two annular seals (16), on either side of the aligned orifices (52, 65), (52 ', 65').

6. winding mandrel according to claim 5, characterized in that the external face (62) of the distribution piece (6) comprises a plurality of connection facets (62 '), in number equal to the number (n) segments, each provided with a pair of external orifices, respectively supply (64) and discharge (64 ^! ), connected to a pair of orifice (75) and outlet (75) respectively '), of the corresponding segment (2), by a pair of connectors of variable length (7, 7') each having an internal end and an external end fixed respectively on a facet (62 ') of the distribution piece (6) and on a connection facet (73) of the segment (2) on which are formed the inlet (75) and outlet (75 ') orifices for the fluid. 7. winding mandrel according to claim 6, characterized in that the ends, respectively internal and external of the fittings (7,

7 ') of each pair are fixed respectively to the connection facets (62', 73) of the distribution piece (6) and of the segment (2), by two plates respectively forming an internal flange (71) and an external flange (71 ').

8. Winding mandrel according to claim 7, characterized in that the external flange (71 ') for fixing each pair of fittings (7, 7') on each segment (2) is fixed on an intermediate plate ( 72) fixed itself on the connection facet (73) of the segment (2) by screws (76) engaging from the outside.

9. Rolling mandrel according to one of the preceding sells, comprising a number (n) of segments (2) and in which the central shaft (1) extends between a rear part connected to means of driving said shaft in rotation around its axis, and a front segment support part (2), characterized in that the radial sliding of the segments is controlled by a rack device comprising a tubular sheath (3) mounted sliding axially on the front part of the central shaft and on which are formed at least (n) faces (31) inclined relative to the axis, each cooperating with a conjugate inclined face (21) of a segment (2) corresponding, for the control, respectively, of the expansion or the constriction of the mandrel by sliding of the sleeve (3) between two positions, respectively moved back and advanced, under the action of a control rod (4) slidably mounted parallel to the axis (X'X) of the central shaft (1) and extended beyond a front end (12) thereof so as to be fixed on a connecting member (40) with the tubular sheath (3), extending transversely in front of the front end (12) of the central shaft (1).

1 0. winding mandrel according to claim 9, characterized in that the tubular sheath (3) slidably mounted on the central shaft (1) extends substantially, in its advanced position, to the level of the range (13 ') for fitting the distribution piece (6), and is extended above it by at least two arms (32) each passing between two pairs of fittings (7, 7') of connection between the distribution piece (6) and the two corresponding adjacent segments, each arm (32) being fixed, by a front end (33), on the transverse member (40) for connection with the control rod (4) sliding.

1 1. Winding mandrel according to claim 10, comprising (n) segments (2) surrounding the central shaft (1), characterized in that the distribution piece (6) comprises (n) facets (62 ') of sealed connection , each of a pair of connecting fittings (7, 7 '), between which are formed (n) sliding faces each forming a sliding support for an arm (32) for controlling the tubular sheath (3).

12. winding mandrel according to claim 1 1, characterized in that the external face (62) of the workpiece distribution (6) has a polygonal shape, the facets (62 ') for connecting the fittings (7, 7') being planar.

13. winding mandrel according to one of claims 10 to 12, characterized in that the transverse member (40) connecting between the control rod (4) and the idler reed (3) consists of a massive part, provided with a central recess (42) which, at least in a rear position of the control rod (4), is threaded on a centering surface (1 5), formed between the front end ( 12) of the central shaft (1) and the interlocking surface (13 ') of the distribution part (6).

14. Winding mandrel according to claim 13, characterized in that, the control rod (4) being slidably mounted in an axial bore of the central shaft (1), the central recess (42) of the transverse connecting member (40), is closed towards the front by a bottom on which the front end of the control rod is fixed.

1 5. winding mandrel according to claim 14, characterized in that the connecting member (40) is extended, forwardly, by a projecting part (44) forming a rocket centered on the axis of the central shaft and capable of taking support i, by means of a bearing (17), on a fixed part.

1 6. winding mandrel according to one of resells ication 9 to 1 5, characterized in that it comprises a protective cover (26), removably attached to the connecting member (40) and s 'extending backwards, so as to cover the whole thereof.

1 7. winding mandrel according to claim 16, characterized in that each segment (2) is extended forward by a curved plate (26 ') having a diameter slightly smaller than that of the cover so (26) to penetrate inside thereof with a possibility of longitudinal sliding to form a substantially continuous protection.

18. Winding mandrel according to one of the preceding claims, characterized in that each segment (2) comprises an internal part (20 ') for supporting the means for controlling the radial sliding and an external part (20) in form of cylindrical sector, produced in mechanically welded construction and comprising two curved plates, respectively internal and external spaced from one another so as to provide a free space divided, by at least one partition parallel to the axis, in at least two chambers, respectively supply and discharge, into which open, respectively, an inlet orifice and an outlet orifice for heat transfer fluid, formed in the internal plate of the segment, at one end thereof, said chambers being placed in communication at the other end of the segment.

19. Winding mandrel according to one of claims 1 to 17, characterized in that each segment comprises an internal part (20 ') for supporting the axial sliding control means and an external part (20) in the form cylindrical sector, consisting of a curved plate (20) in the thickness of which are formed a plurality of channels (24, 24 ') parallel to the axis of the mandrel and distributed over the entire surface of the segment in two series , respectively (24) supply and (24 ') discharge, each opening at a front end of the segment, in a distribution chamber (25, 25') integral with the segment (2) and provided with an orifice , respectively inlet (75) or outlet (75 ') of the fluid, the channels (24, 24') of the two series being connected together, at a rear end of the segment, by a common distribution chamber (23) .

20. winding mandrel according to claim 10, comprising a number (n) of segment and in which each arm (32) for controlling the sliding of the sheath (3) is fixed, by a front end (33), on a rear face of the transverse member (40) connecting with the control rod (4), characterized in that it comprises a lubrication circuit, at least, inclined faces (31) for controlling the sliding of the segments comprising, for each inclined face (31), at least one orifice (80) grease outlet, placed at the outlet of a pipe (81) extending along the sheath (3) and extended by a part (82) along at least one sliding control arm to an orifice supply (83) placed on the front end (33) of said arm (32) and coming to connect, by fixing the connecting member (40) on said arm (32), on a tube (83 ') sealed connection, carried by the connecting member (40), and connected to a means (8, 48) for introducing grease pressure.

21. Winding mandrel according to claim 20, characterized in that each tube (83) for connection of the lubrication circuit is formed on a rear face of the connecting member (40), on which the end is applied. front (33) of the corresponding control arm (32) of the sheath (3) and is placed at the outlet of a conduit (84) extending, at least in part, inside the connecting member (40 ), to a grease introduction orifice (85).

22. Winding mandrel according to claim 21, in which the control rod is centered on the axis of the mandrel and fixed, by a front end, on a transverse part constituting the connecting member (40) with the sheath ( 3), characterized in that the front end of the control rod (4) is provided with a cylindrical seat (44 ') which fits into a conjugate bore (44) formed in the center of the connection (40) and into which at least one orifice (85) grease inlet opens, connected by a conduit (84) to the connection pipe (83 ') carried by the connection member (40), and that the control rod (4) is provided with at least one channel (8) extending longitudinally between a rear orifice connected to the means (48) for introducing grease and a front orifice formed on the nesting surface (44 ′) of the control rod, and placed in communication with the grease inlet orifice opening into the bore (44) of the connecting piece (40), after fitting the control rod (4) therein.

23. winding mandrel according to claim 22, characterized in that the bearing surface (44 ') of the control rod (4) is provided with at least one groove (46) which, in the nested position of the control rod, is located at the orifice (85) for introducing grease opening onto the central bore (44), said groove (46) being framed by two annular seals (49 ).

24. winding mandrel according to one of claims 20 to 23, comprising at least two series of inclined faces (31) for controlling the radial displacement, respectively, of each segment (2), centered on two transverse mean planes spaced longitudinally , each segment (2) being associated with one face of each series, characterized in that the lubrication circuit comprises, for each series of inclined faces (31), at least one pipe (82, 81) extending along a control arm (32), from a supply orifice (83) placed on the front end (33) of said arm (32) to a bifurcation placed at the level of said series of inclined faces , from which said pipe (81) divides into at least two branches (86) each opening into an outlet orifice (80) formed on one of the inclined faces (31) of said series.

25. Winding mandrel according to one of claims 23 and 24, characterized in that the inclined faces (31) for controlling the radial sliding of the segments (2) are divided into at least two groups each associated with a circuit of lubrication, that the control rod is provided with at least two longitudinal channels (8, 8 ') each opening into a groove (46, 46') of the nesting surface (44 '), that the central bore of the connecting piece is provided with at least two groups of orifices (85) coming in coincidence, in the fitted position, each with a groove (46, 46 ') of the interlocking surface (44'), and each connected to a branch pipe (83 '), that the tubular sheath (3) carries at least two groups of associated pipes (82, 81, 81') respectively said groups of inclined faces, each pipe (82) extending along a control arm (32), from a supply orifice (83) connected to one of the connection pipes (83 '), up to at least one grease outlet orifice (80) opening into at least one inclined face (31) of the corresponding group, and the mand rin is associated with a central lubrication system ised for controlling the 'introduction under grease pressure, alternatively, in one or other of the lines (8, 8') of the control rod (4) and the lubrication of the either of the groups of inclined faces (31).