FR2631864A1 - Multi-function machining head for machine tools - Google Patents

Abstract

Multi-functional machining head 1 for machine tools, intended to receive rotating tools and fixed tools. This head comprises a ring B mounted so that it can rotate on a body A which is fixed with respect to it, this ring including both a fixture 4 for a rotating tool and a fixture 5 for a fixed tool, the locations provided for these tools being located at the periphery of the ring B, means for indexing the angular position of the ring B with respect to the body A and means for driving the fixture 4 for the rotating tool regardless of the indexing position of the ring B. Application to the performing of very varied machining operations without resetting the workpiece.

Description

 The present invention relates to a multipurpose machining head for equipping a machine tool of any type, but advantageously numerically controlled.

 This head is intended to receive cutting tools, fixed or rotary, working by removing chips to allow the realization of the most varied machining operations.

 In particular, with a stationary tool, the head makes it possible to carry out horizontal or vertical turning operations, exterior or interior turning, slotting and grooving and with a turning tool, the milling, boring, drilling and tapping operations.

Specialized machining heads are already known which are capable of receiving fixed or rotary tools of various types and which are intended to equip traditional or numerically controlled machine tools, in particular
- "orientable" heads of milling machines or boring machines,
- the so-called "universal" heads of milling machines or boring machines,
- heads with "revolver turrets" for boring machines, drilling machines, machining centers,
- sliding heads.

The preceding machining heads however have various drawbacks and limitations which have been recognized in the context of the present invention. In particular
- these multiple tool heads generally target # the equipment of specialized machines and are adapted to these machines, so that their versatility is limited
- These heads are often bulky, which limits for a given machine, the nature of the parts likely to be machined if one does not want to proceed with a recovery of the part;
- Known multi-tool machining heads often only develop limited working power for rotary tools, so multi-tool turrets generally cannot work beyond two kW
- The rigidity of the fixing often leaves something to be desired, which limits the precision of the machining;
- the mounting and fixing of tools often prohibits an automatic tool change, which considerably limits them. possibilities for machine tool automation.

 The present invention aims to remedy all of the aforementioned drawbacks by presenting a machining head with very high versatility, adaptable to machine tools and to the most varied known machining centers, this head also having a remarkable compactness of likely to allow multiple machining operations without reworking of parts.

 The invention is in fact based on the discovery that it was possible to meet the above specifications with only two tool locations; angularly distinct, respectively for a fixed tool and a rotating tool, under the condition that the rotating tool can be put into work in the various indexing positions provided for the head.

 In addition, the multi-purpose head according to the invention aims to offer the greatest possible compactness to the user, while allowing high-precision machining, with high cutting power (for example of the order of 8 kw) and in authorizing an automatic tool change both with regard to the cutting profile of this tool as its fixed or rotating nature.

 According to the invention, the multipurpose machining head for machine tools, intended to receive rotary tools and stationary tools, is characterized in that it comprises a crown rotatably mounted on a body fixed relative to it, this crown comprising both a mount for a rotating tool and a mount for a stationary tool, the locations provided for these tools being at the periphery of the crown, means for indexing the angular position of the crown relative to the body and means to drive the mounting of the rotating tool whatever the indexing position of the crown.

 The invention thus makes it possible, with remarkable economy of means, to meet very extensive machining specifications.

 According to a preferred embodiment of the invention, the axes of the mounts of the rotary and fixed tools are located in the same plane orthogonal to the axis of rotation of the crown on the body and are also orthogonal to one another.

 The invention also preferably provides that the mounts of the rotary and stationary tools include similar tool clamping devices.

 In a preferred embodiment, the drive of the rotary tool is ensured by means of a motor shaft directed along the axis of the crown, mounted in the body, protruding from it and which attacks by a reference a 'angle with pinions the rotary spindle of the rotary tool mount.

 According to another preferred feature of the machining head according to the invention, the frame of the fixed tool comprises a stirrup arranged in a transverse plane and in particular orthogonal, -to the axis of the rotating tool, this bypassing stirrup the mount provided for the latter.

 The invention thus triumphs over a prejudice by producing a crown with two intersecting axes.

 According to another preferred feature of the invention, the tool-holder ring is capable of a certain displacement in translation along its axis, which coincides with the axis of the body which carries it, facing stops, in particular of frustoconical profile, being arranged on the crown and on the body and a cylinder arranged between the body and the crown allowing * 'bring these stops in blocking contact to put the crown in the working position.

 According to a preferred feature of the machining head according to the invention, the means for indexing the crown relative to the body comprise a notched plate carried by the crown, the position of the notches corresponding to the indexing positions, a articulated fork carrying an indexing finger intended to be removably engaged in one of said notches by displacement of the fork in a direction substantially orthogonal to the notched plate, means for controlling the engagement or disengagement of the finger indexing relative to the notches and means for rotating the crown relative to the head and scrolling the notches in front of the indexing finger.

 These simple and economical means allow very precise indexing, especially if the fork carrying the indexing finger is connected to the body by a pseudoarticulation with an elastic blade.

 According to another characteristic of the invention, the means for driving the crown relative to the head, in particular in the case where the indexing positions are in discrete number, comprise a connection with the Maltese Cross.

 Other features and advantages of the invention will also result from the description below.

 In the accompanying drawings, given by way of nonlimiting examples, a preferred embodiment of the multipurpose machining head according to the invention has been shown.

 Figure 1 is a side elevational view of the head.

 Figure 2 is an end view of the side of the crown, the fixed and rotating tools not being engaged.

 Figure 3 is a perspective diagram of the body and the crown of the head, the shutter plate of the crown being assumed to be apart.

 FIG. 4 is a simplified view on a larger scale of the head, in section through the axial plane IV-IV of FIG. 2.

Figure 4A is a large-scale view of the detail
VA of figure 4.

Figure 5 is a more detailed view than Figure 4 in section through the axial plane VV orthogonal to the plane IV
IV.

 Figure 6 is a sectional view through the plane V = -VI of Figure 4 showing the means of indexing the crown.

 FIG. 7 is a front view of the plate of the body carrying the indexing notches.

 Figure 8 is an elevational view after section along Vili-Vili of Figure 5 showing the indexing device of the crown.

 FIG. 8A is a detail view on a larger scale, in section along VIIIA-VIIIA-of FIG. 8.

 FIG. 8B is another detail view on a larger scale in section along VIIIB-VIiIB of FIG. 4.

 Figure 9 is a more detailed partial sectional view than Figure 6 showing the indexing device during operation.

 Figure 10 is a sectional view along an axial plane of the sleeve for coupling the crown to the body.

 FIG. 11 is an illustrative diagram of the hydraulic control means provided for the head.

 FIG. 12 shows by way of illustration in axial section the various machining operations that can be carried out on a part of revolution with the head according to the invention.

 Figure 13 is the corresponding end view.

Figure 14 is the section along XIV-XIV of the
figure 12.

Referring to Figures 1 to 3 of the drawings
annexed, a preferred embodiment of a multi-purpose head 1 can be seen in accordance with the invention.

This head 1 essentially comprises a body A
UU axis on which is mounted with a certain degree of
freedom in axial translation along UU and in rotation
around UU, a tool crown B which is provided with a coupling sleeve 2 partially surrounding the body A
and allowing its connection with it.

The head 1 can be mounted, via a plate 3 of the body A, at will at a fixed station or on a
lathe, a milling machine or a machining center in which case it can be made mobile in space along three axes
Y, Z two to two orthogonal. The UU axis could also be articulated around one of the X, Y or Z axes or relative to a center of rotation. Preferably, this head is intended to equip a machining center comprising a lathe, of the type referred to by the applicant's French patent application, filed jointly and entitled
In the description which follows, it will be assumed for simplicity that the body A is fixed in space.

 Crown B has a polygonal outline (Fig.

2) and carries at its periphery both a mount 4 for a rotating tool 6 and a non-rotating mount 5 for a stationary tool 7. In FIG. 2, the tools 6 and 7 are shown before their installation in the mounts respective.

 As can be seen in FIGS. 2 and 3, the axes W and X of the mounts 4 and 5 are orthogonal to the axis U-U of rotation of the crown B on the body A and they are moreover orthogonal to one another. According to another feature of the invention, the mounts 4 and 5 comprise similar tool clamping devices with a standardized tool grip of the tool shank so as to allow complete interchangeability of the tools.

 More particularly, the rotary tool mount 4 comprises a spindle 8 having a frustoconical opening 10 for engaging the shank of the tool. The spindle S is extended along its axis W-W by a .tube 12 rotatably mounted in the carcass 13 of the crown B by means of bearings 14 placed on either side of the axis U-U. The frame 4 also carries a bevel gear 16, orthogonal to the axis WW intended to allow its drive in rotation from a drive gear 17 orthogonal to the axis UU, the assembly of the gears 16 and 17 constituting a reference of right angle movement.

 The pinion i7 is formed at the end of a drive shaft 18 driven by any motor means of a known type, not shown, and which passes axially along UU the body A. The shaft 18 is housed in a bore axial 19 of this body where it is guided by bearings 20.

 At the internal end of the bore 19 and opposite a bowl 21 of the carcass 13, the body A has a flange 22 with a dropped edge 23 (FIG. 4A) whose role will be seen below.

 The bowl 21 opens into a central chamber 15 formed in the carcass 13 of the head B. This chamber 15 is closed by a removable cover 34 whose center has a perforated air intake 34a whose role will be seen later.

 The mounting for fixing the shank 6a of the rotary tool 6, of a kind in itself known, comprises inside the spindle 4, locking balls 24 trapped between this spindle fixed in translation and a axial slide 26 movable along the axis WW. The slide 26 is subjected to the opposing actions of an elastic system 28 for returning upwards in the position of FIG. 4 (such as a coil spring or preferably a stack of Belleville-type washers) and a hydraulic cylinder 30 of loosening housed in a projection 31 of the carcass 13 on the side opposite to the rotating spindle 4.

 The jack 31 comprises a cylinder 32 in which is mounted a piston 33 which can press on the free end 26a of the slide 26.

 If the piston 33 is moved along F (Figure 4), it pushes the slide 26 and allows the balls 24 to escape into an annular housing 10a of the spindle 4. We can then put in place the shank 6a of the tool turning 6 which is positively tightened when the slide 26 returns to its initial position under the action of the elastic system 28.

 For its part, the mount 5 for fixing the shank 7a of the stationary tool 7 comprises (FIG. 5) a pin q formed in the carcass 13.

 Pin 9 has, like pin 8, a frustoconical entry 11, terminated by an annular housing Ila. Locking balls 25 are trapped between the spindle q and a slide 27, movable along the axis X-X of the crown B.

 According to a remarkable feature of the invention, the slide 27 belongs to a solid stirrup 29, located in a plane U-X orthogonal to the axis W-W of the rotary tool. 6 and which bypasses the rotary tube 12 of the mount 4.

 On the opposite side of the spindle 4, the stirrup 29 carries an axis 29a engaged in a bearing 35 arranged in a projection 37 of the carcass 13 on the side opposite to the spindle 9.

 The stirrup 29 is biased along G (loosening position) by a helical spring 39 (or similar elastic means) surrounding the axis 29a.

 This action is antagonistic to that of a hydraulic clamping cylinder 41, disposed around the housing 11a and which comprises an annular piston 42 movable in a cylindrical groove 43 formed in the spindle 9.

 The free end of the piston 42 bears on a bearing surface 44 of the caliper 29.

 It is understood that if the jack 41 is not supplied with pressurized oil, the thrust of the elastic members 39 on the stirrup 29 and the slide 27 causes the latter to descend along G (in FIG. 5), which brings the balls 25 into the annular housing IIa and makes it possible to engage the shank 7a of the stationary tool 7 in the bottom of the spindle 9.

 The pressurization of the jack 41 then ensures the tightening of the tool 7 by the balls 25.

 According to another aspect of the invention, the tool-holder ring B is capable, not only of a rotational movement around the axis UU but also of a certain translation along this axis, this in order to allow its indexing in the desired working position of the tool 6 or 7 relative to the body A. Means are also provided to ensure very precise setting of the crown B on the body A in the working position. To this end, (FIG. 4 or 5), the body A has a first frustoconical bearing 51 formed on an annular sleeve 52 and a second frustoconical bearing 53 on a sheath 54 (draw sheet following the bore 19) and which projects beyond from sleeve 52 to crown B.

 For its part, the sleeve 2 of the crown 3, which is attached to the carcass 13, has two frustoconical bearing surfaces 55 and 56 stepped, facing the bearing surfaces 51 and 53.

The bearing 56 is extended by a bearing 57 adjusted on a bearing 58 of the sheath 54 so as to be able to slide and rotate thereon. The two pairs of frustoconical surfaces thus provided are made of nitrided steel and surfaced with maximum precision.

 The bearing surfaces 55 and 56 of the sleeve 2 as well as the bearing 57 are particularly visible in FIG. 10, where the sleeve 2 is assumed to be isolated from the carcass 13.

 Means are also provided to ensure at will the setting of the sleeve 2 against the body A in the working position or the unclamping thereof to allow a change of indexing. These means comprise (FIG. 4A) a hydraulic cylinder 61 comprising an annular piston 62 coaxial with the axis U-U, trapped in the annular housing 63 formed by the flange 22 and the fallen edge 23 ending the sleeve 54.

 One of the faces of the piston 62 is supported on a transverse surface 64 formed by the bottom of a cup 65 formed in the front face of the sleeve 2.

 According to yet another aspect of the invention, illustrated in particular in FIGS. 6 to 9, the means for indexing the crown B relative to the body A comprise a plate 66 with notches 67. The plate 66 can be either machined in the face of the sleeve 2 situated opposite the body A, as shown diagrammatically in FIGS. 4 and 6, is preferably constituted by a crown 68 attached to said face by screws 69 as shown in FIG. 7.

 In the example considered, four indexing positions are provided at 900 from each other and a capacity for rotation of the crown B relative to the body A of 2700.

 To this end, the plate 66 has four notches 67 to 900. The notches 67 are preferably slightly trapezoidal as shown in FIGS. 7 and 9.

 The indexing means further comprise (FIGS. 8 and 8a) a fork 71 movable transversely, substantially orthogonal to the axis U-U and surrounding the sheath 54 of about 1800. The fork 71 carries in its middle part an indexing finger 72 directed towards the notches 67 and adapted to their profile.

 In the preferred embodiment shown in FIGS. 8 and 8A, the fork 71 is connected to the body A by a pseudo-articulation constituted by two flexible blades 73 made of spring steel respectively fixed to the body A and to said fork 71 by screws 74 and 75 .

 Means are provided for controlling the engagement or disengagement of the finger 72 relative to the notches 67.

These means comprise a jack 76 housed in the front face 77 of the body A and whose piston 78 (movable according to G-G1) is terminated by a open head 79 trapped in the fork 71 opposite the indexing finger 72 (FIG. 8B ).

 Other means are provided for rotating the crown B relative to the head A in order to bring it to the desired indexing position (by scrolling the notches 67 in front of the finger 72). These means, in particular in the case of a limited number of indexing positions as provided by the example described, include a drive link of the Maltese Cross type.

 To this end, the body A carries on the side opposite the indexing finger 72 with respect to the axis UU a chamfered disc 80 rotatably mounted around an axis TT on a motor shaft 81 parallel to the axis UU and which carries a roller 82 and a cam 83 offset relative to the axis TT. The roller 82 and the cam 83 can come into engagement with a succession of radial housings 84- and semi-circular sections 85 alternating on the plate 66. The indexing notches 67 follow the housings 84 (FIG. 7).

 The rotation of the disc 80 is permitted by virtue of an annular recess 86 of the sheath 54.

 The drive of the shaft 81 is provided by a motor 87 and a gear 88 (FIG. 4), such as a hydraulic motor.

 The control of the various jacks and of the motor 87 arranged on the head 1 is ensured from a hydraulic unit 89 (FIG. 11) comprising a motor pump 90, a high pressure circuit 91, a low pressure circuit 92 to which a set of distributors with drawers 93, 94, 95, 96, 97 controlled by electrical relays.

The high pressure circuits downstream of the distributors 93, 94 and 95 are shown diagrammatically at 103, 104 and 105, they serve respectively:
the jack 30 for loosening the rotary tool 6,
the jack 41 for clamping the stationary tool 7 (on the circuit 104 is mounted a safety device liO for maintaining the clamping pressure),
- And finally the jack 61 for locking the crown B on the head A.

 The distributor 96 leaves the lines 111 and 112 which supply the double-acting indexing cylinder 76.

 Line 111 ensures locking of finger 72 in notch 67 and line 112 allows unlocking.

Finally, the lines 113 and 114 supplied by the distributor 97 allow the rotation of the indexing change motor 87 selectively in one direction or the other.

 As can be seen in FIGS. 4 and 5, the lines 103 and 104 for controlling the loosening of the rotating tool and the clamping of the fixed tool pass through the body A parallel to the axis UU and end in flexible coils 103a , 104a coaxially wound around the sleeve 2.

These coils must allow at least 2700 rotation of the crown B with respect to the body A.

 The coil 103a is extended by a conduit 103b formed in the carcass 13 and which terminates in the cylinder 32 of the release cylinder 30 (FIG. 4).

 Similarly, the coil 104a opens into a conduit 104b of the carcass 13 and ends in the annular groove 43 of the clamping cylinder 41 (Figure 5).

 This arrangement allows a permanent supply of the cylinders of the crown B in all positions thereof.

 FIG. 4 also shows the pipes 105, 111 and 112 made in the body A, the pipe 105 being extended inside the sheath 54.

 According to yet another aspect of the invention, there is provided a lubrication system for the drive of the rotary mount 4 and more particularly of the pinions 16 and 17 as well as the windings 14, by means of an oil supply under pressure by an axial conduit 113 formed in the motor shaft 18 which supplies a terminal nozzle, which diffuses the lubricant towards the teeth in engagement of said pinions.

The lubricant is discharged through a circuit that is not shown, which serves the parts in contact with the sleeve 2 and the crown
AT.

 Given the detailed description above, the implementation and operation of the machining head are easily understood.

To ensure the indexing of the crown B, one starts by purging the jack 61, which ensures the unclamping of the crown B which can then rotate with gentle friction around the axis UU by sliding the bearing 57 around the scope 58,
The indexing finger 72 is pulled out of the notch # 67 by contraction of the jack 76, the open head 79 of which pulls on the fork 71. The displacement of this fork substantially parallel to the axis UU is possible thanks to the pseudo-articulation formed by the blades 73.

 The engine 87 is then started. The rotation transmitted by the shaft 81 to the disc 80 causes the roller 82 and the cam 83 to penetrate successively into the radial 84 and circular 85 housings of the plate 66 (FIG. 9).

 Thanks to this reduction obtained by training in the Maltese Cross, the sleeve 2 rotates very smoothly and very precisely.

 When the desired indexing notch 67 is opposite the finger 72, the motor 87 is stopped and the indexing cylinder 76 pushes the fork 71 and the finger 72 into this notch 67.

 The prismatic outline of these parts makes it possible to complete the indexing.

 The crown B is then fixed on the body A by actuation of the jack 61, the piston 62 of which pushes on the bearing surface 64.

 If the rotary tool 6 must be put into work, it suffices to drive the shaft 18 which transmits its rotation to the frame 4 by the pinions 16 and 17.

 Experience has shown that a multipurpose head according to the invention can easily allow the drive of a tool 6 to 8000 rpm and the transmission of a power of 8 kw.

Lubrication of rotating parts is ensured
r by spraying an oil mist through the nozzle 114, when the rotary tool is put into service. The air intake 34a of the cover 34 allows the creation of an air current which sprays the oil in a mist. The latter is evacuated via conduits 137 (Figure 5) to a collector not shown.

 The versatility of the indexable head with only two tools is illustrated by Figures 12 to 14 where we see a piece D of the kind used in valves, of revolution around the axis SS clamped between the jaws 120 of a spindle which can make it rotate around the aforementioned axis.

 Without resumption of the part D, it is possible to carry out its cylindrical trimming according to 121 by a roughing tool 01,. followed by a threading of the endpiece 122 by a threading tool 02. A transverse groove 123 can be releaded by a grooved tool 03.

 The front face of the part D can be turned at 124 by a fixed reamer 04 and in the part thus bored, it is possible to make blind holes 125 in the form of a buttonhole (FIG. 13) using the cutter 05.

 The part D can also be drilled according to an eccentric pipe 126 by means of a rotary reamer 07 (FIG. 14).

 It should be understood that the invention is not limited to the embodiments described and that variant embodiments can be made to them.

 Thus, the indexing device could include more than four positions by increasing the number of indexing notches.

 One could thus provide a continuous indexing system on 3600 by controlling the rotation of the crown 2 relative to the body A by means of a tangent screw system, the position of the crown being identified by the number of turns or fractions of turn of the screw.

 Similarly, the pseudo-articulation of the fork 71 by elastic blade could be replaced, but less favorably, by a real articulation of said fork 71 around an axis orthogonal to the axis U-U.

 It will also be noted that the uniformity of the fixed and rotary mounts provided for the tools makes it possible to associate with the head 1 a tool changing device of a conventional type with fork or barrel. Such a device 131 with a rotary fork 132 has been shown in FIG. 11. The fork 132 is controlled in rotation by a hydraulic motor 133 supplied by lines 134, 135 through a distributor 136 connected to lines 91 and 92. It is possible to thus successively place on the head 1 any number, as large as desired, of fixed or rotary tools by associating with the device 131 an endless tool chain.

Claims (18)

 1. Multipurpose machining head (1) for machine tools, intended to receive rotary tools (6) and stationary tools (7), characterized in that it comprises a crown (B) mounted mounted = rotatably on a body ( A) fixed relative to it, this ring (B) comprising both a mount (4) for a rotating tool (6) and a mount (5) for a fixed tool (7), the locations provided for these tools are located at the periphery of the crown (B), means for indexing the angular position of the crown (B) relative to the body (A) and means for driving the mount (4) of the rotary tool (6) which whatever the indexing position of the crown (B).  2. Machining head according to claim 1, characterized in that the axes (WW and XX) of the mounts (4 and 5) of the rotating (6) and fixed (7) tools are located in the same plane orthogonal to the 'axis (UU) of rotation of the crown  (B) on the body (A).  3. Machining head according to one of claims 1 or 2, characterized in that the axes (WW and XX) of the mounts (4 and 5) of the rotating (6) and fixed (7) tools are orthogonal to each other .  4. Machining head according to one of claims 1 to 3, characterized in that the mounts (4 and 5) of the rotating tools (6) and fixed (7) comprise similar tool clamping devices.  5. Machining head according to one of claims 1 to 4, characterized in that the drive of the rotary tool (6) is ensured by means of a motor shaft (18) directed along the axis (UU) of the crown (B) mounted in the body (A), protruding from it and which attacks by a bevel gearbox (16, 17) the rotary mount (4) of the rotating tool <6).  6. Machining head according to one of claims 1 to 5, characterized in that the fixing mounts (4 and 5) of the tools comprise inside a spindle (8 or 9) balls (24 , 25) tail lock  (6a, 7a) of the tool, trapped between this spindle (8, 9), fixed in translation and a slide (26, 27) housed in this spindle (8, 9) and subjected to the opposing actions of an elastic system (28, 39) return to the fixed position and a jack  (30, 41) for controlling the tightening or loosening of the shank  (6a, 7a) of the tool.  7. Machining head according to one of claims 1 to 6, 'characterized in that the mount (9, of the fixed tool (7) comprises a stirrup (29) disposed in a transverse plane, and in particular orthogonal , to the axis (WW) of the rotary tool (6), this stirrup (29) bypassing the frame  (4) provided for the latter.  8. Machining head according to claim 7, characterized in that the stirrup (24) is movable in translation in its plane under the action of the release cylinder (41! Of the shank (7a) of the tool (7).  9. Machining head according to one of claims 1 to 8, characterized in that the tool holder ring (B) is capable of a certain displacement in translation along its axis (UU) which coincides with the axis of the body (A) which carries it, facing stops (51, 53 and 55, 56) being arranged on the body (A) and on the crown (B) and a jack (61) disposed between the body (A) and the crown (B) making it possible to bring these stops into blocking contact to put the crown (B) in the working position.  10. Machining head according to claim 9, characterized in that the stops (51, 53 and 55, 56) for setting the crown (B) on the body (A) are constituted by two frustoconical bearings stepped along of the axes (UU) of the body (A) and of the crown (B).  11. Machining head according to one of claims 9 or 10, characterized in that the drive shaft (18) of the mount (4) of the rotary tool (6, of the crown (B) is coaxial with the body (A) and carries at its end a bevel gear (17) housed in a cup (21) formed in the lateral face of the crown (B) which is directed towards the body (A).  12. Machining head according to one of claims 6, 7 or 8, characterized in that the timing cylinder (61) of the crown (B) on the body (A) is annular and coaxial with them .  13. Machining head according to one of claims 6 to 8, characterized in that the jacks (41, 30) of the crown (B) allowing the tightening or loosening of the tools (6, 7) are supplied with working fluid by coils (103a, 104a) arranged around the body (A) with a clearance allowing the indexing rotation of the crown (B).  14. Head according to one of claims 5 to 13, characterized in that the lubricating device of the rotary spindle drive for the rotary tool comprises an oil supply channel (113) arranged along the axis (Ultr) of the motor shaft (18) which serves means (114) for spraying the oil towards the drive means (16, 17) of the mounting (4) of the rotary tool (6 ).  15. Machining head according to one of claims 1 to 14, characterized in that the means for indexing the crown (B) relative to the body (A) comprise a plate (66) with notches (67) carried by the crown (B), the position of the notches (67) corresponding to the indexing positions, an articulated fork (71) carrying an indexing finger (72) intended to be removably engaged in one of said notches (67) by displacement of the fork (71) in a direction substantially orthogonal to the plate (66) with notches, means for controlling the engagement or disengagement of the indexing finger (72) relative to the notches (6, 7) and means for rotating the crown (B) relative to the head (A) and scrolling the notches (67) in front of the indexing finger (71>.  16. Machining head according to claim 15, characterized in that the fork (71) carrying the indexing finger (72) is connected to the body (A) by a pseudoarticulation with elastic blade (73).  17. Machining head according to one of claims 15 or 16, characterized in that the drive means of the crown (B) relative to the head (A), especially in the case where the positions of indexing are limited, include a link to the Maltese Cross.  18. Machining head according to claim 17, characterized in that the Maltese cross connection comprises on the side opposite the indexing finger (72) relative to the axis (UU) of the body (A) a disc rotary (80) carrying an eccentric roller (82) and a cam (83), capable of cooperating with profiled housings <84, 85) distributed on the plate (66) with notches (67) and nested with respect to these.