Polishing or brushing head

Abstract

Disclosed is a polishing or brushing head for a machine tool, comprising: - a plurality of shoes, each shoe being intended to receive or receiving an abrasive tool intended to come into contact with the surface of a material to be polished or brushed, each shoe being able to rotate about an axis of rotation between a first position and a second position, different from the first position, and - at least one pneumatic actuator configured to act on each shoe to cause it to oscillate about its axis of rotation between the first position and the second position.

Description

Description Title of the invention: Polishing or brushing head technical field

[0001] The present invention relates to the field of polishing and brushing hard materials, such as granite, marble and concrete.

[0002] In particular, it relates to a polishing or brushing head, a machine tool comprising a spindle and at least one polishing or brushing head, and a polishing or brushing process. Technological background

[0003] Generally, for polishing hard materials, such as granite, marble and concrete, a machine tool has a plurality of polishing heads, for example 5 to 8 polishing heads, and a spindle.

[0004] Each polishing head extends along a longitudinal axis, and the spindle is configured to receive and rotate each polishing head around its longitudinal axis, successively.

[0005] Each polishing head has a proximal end and a distal end, opposite the proximal end.

[0006] The proximal end of the polishing heads is intended to be connected to the spindle of the machine tool.

[0007] The distal end of the polishing heads is intended to come into contact with the surface of the material to be polished.

[0008] In particular, the distal end of the polishing heads has a plurality of shoes, each receiving an abrasive tool intended to come into contact with the surface of the material to be polished.

[0009] Thus, it is the contact of the distal end of the polishing heads, driven in rotation by the spindle, with the surface of the material to be polished that allows the polishing of the surface of the material to be polished.

[0010] Typically, the abrasive tools on a single polishing head have the same grit size. However, the abrasive tools on each polishing head have different grit sizes.

[0011] As a general rule, the higher the grain size number, the smaller the grain diameter.

[0012] Polishing is carried out by successively using each of the polishing heads driven in rotation by the spindle, so that the abrasive tools successively in contact with the surface of the material to be polished have an increasing grain size number, which allows for increasingly fine polishing.

[0013] Polishing is performed under a constant flow of coolant, such as water or another lubricant. The coolant is delivered under pressure through a channel located in the center of the spindle and polishing head, directly to the surface of the material being polished. Using coolant during polishing lubricates and cools the surface of the material. It also allows for the removal of debris and dust produced during the polishing process.

[0014] For polishing hard materials, such as granite, marble and concrete, the aim is to apply the polishing head against the surface of the material to be polished with a controlled point or linear force so as not to risk breaking the material to be polished.

[0015] It is therefore necessary to apply this controlled point or linear force on the smallest possible surface of the material to be polished, so as to obtain the greatest possible contact pressure throughout the polishing process.

[0016] It then becomes necessary to minimize the contact area between the polishing head and the material to be polished throughout the polishing process.

[0017] To meet this need, polishing heads have been developed in which the shoes are each mobile in rotation around an axis of rotation, either continuously (the abrasive tool is then generally called a "satellite" and we speak of satellite polishing heads), or between a first position and a second position, different from the first position, so that each of the shoes can oscillate between the first position and the second position, like a pendulum (the abrasive tool is then generally called a "segment" and we speak of segment polishing heads).

[0018] This rotational movement of the shoes can also allow the regeneration of the abrasive tools received on said shoes, and in particular to limit or even eliminate the risk of formation of flat faces (also called facets) on said abrasive tools, which allows to maintain the highest possible contact pressure throughout the polishing.

[0019] Regarding satellite polishing heads, it is known to achieve continuous rotation of the polishing pads using hydraulic motors integrated into the polishing head and driven by its rotation. A drawback of this solution is that the pad rotation speed is dependent on the polishing head's rotation speed, since the hydraulic motors are driven by the head's rotation. Furthermore, this requires integrating not only the hydraulic motors but also a hydraulic pump and valves into the polishing head. Therefore, integrating such a hydraulic system within the polishing head adds complexity due to the increased number of additional components.Integrating such a hydraulic system into the polishing head presents another drawback: the increased weight of the polishing head due to the additional components, making these polishing heads unsuitable for use with small machine tools. Furthermore, integrating such a hydraulic system into the polishing head carries a risk of oil leakage.

[0020] Regarding segmented polishing heads, it is known to achieve the oscillation of the polishing shoes using a mechanical transmission via gears and / or cams. However, with such a mechanical transmission, the oscillation frequency of the shoes is linked to the rotational speed of the polishing head and the reduction ratio. Therefore, when it is necessary to decrease the rotational speed of the polishing head during polishing to adapt it to the abrasive tool / material pairing—for example, when the abrasive tools successively contacting the surface of the material to be polished have an increasing grit number—the oscillation frequency of the shoes is necessarily also reduced, which in turn decreases the contact pressure between the polishing head and the material being polished.Furthermore, the integration of such a mechanical transmission within the polishing head results in the latter being heavier, making it incompatible with small machine tools.

[0021] Regarding segmented polishing heads, it is still known to achieve the oscillating movement of the pads using the energy of the water jet. Specifically, the water jet is pressurized, which causes A rotation of each shoe from a first position to a second position, followed by the cessation of the water pressure supply, causes each shoe to return to its first position thanks to return springs. This sequence is repeated to produce oscillations of the shoes between the first and second positions. However, such a system has the disadvantage of being dependent on the flow rate and pressure of the water supply, and therefore on the flow rate and pressure of the water circuit to which the machine tool is connected for watering. Furthermore, the cessation of the water pressure supply, i.e.The interruption of the water supply, which causes each of the shoes to return to the first position thanks to the presence of return springs, can lead to traces of overheating on the surface of the material to be polished, a heterogeneity of the finish due to the degradation of the quality of the polishing and an erratic operation due to the response time of the return springs.

[0022] The invention aims to further improve the devices and processes used for polishing or brushing materials, in particular hard materials, and in particular to remedy all or part of the above-mentioned drawbacks.

[0023] Its aim is in particular to further improve the efficiency and quality of polishing and / or brushing of materials, especially hard materials. Summary of the invention

[0024] Polishing or brushing head for machine tool

[0025] The invention thus relates, according to a first aspect, to a polishing or brushing head for a machine tool comprising: - a plurality of shoes, each shoe being designed to receive or receiving an abrasive tool intended to come into contact with the surface of a material to be polished or brushed, each shoe being movable in rotation around an axis of rotation between a first position and a second position, different from the first position, and - at least one pneumatic actuator configured to act on each shoe to make it oscillate around its axis of rotation between the first position and the second position.

[0026] The pneumatic actuator is thus configured to act on the shoes to make them oscillate between the first position and the second position, like a pendulum.

[0027] The polishing or brushing head according to the invention is particularly advantageous insofar as it is possible to independently control its rotation speed, the oscillation frequency of the shoes, as well as the flow rate and pressure of the watering fluid, unlike the solutions proposed in the prior art in which the oscillation frequency is dependent either on the rotation speed or on the flow rate and pressure of the watering fluid.

[0028] The polishing or brushing head according to the invention can maintain the same polishing or brushing performance on a wide variety of materials, particularly in terms of hardness and chemical composition.

[0029] Similarly, the polishing or brushing head according to the invention can maintain the same polishing or brushing performance with a wide variety of abrasive tools, particularly in terms of grit size. For example, when it is necessary to decrease the rotational speed of the polishing or brushing head during polishing to adapt it to the abrasive tool / material to be polished, especially when the abrasive tools successively contacting the surface of the material to be polished have increasing grit sizes, it is possible to compensate for the decrease in the rotational speed of the polishing or brushing head by increasing the oscillation frequency of the pads, since the polishing or brushing head according to the invention can control the oscillation frequency of the pads independently of the rotational speed of the polishing or brushing head.This can ensure contact between the abrasive tools and the surface of the material to be polished or brushed along a line rather than on a flat surface, thus improving efficiency (i.e., the number of strokes). 2 polished or brushed per hour) and the quality of polishing or brushing.

[0030] Furthermore, since the polishing or brushing head according to the invention can control the oscillation frequency of the pads independently of the flow rate and pressure of the coolant, the polishing or brushing head can allow polishing or brushing under continuous coolant flow, without interrupting the coolant supply, which limits or even eliminates the risk of overheating marks appearing on the surface of the material to be polished or brushed and the risk of unevenness in the finish due to a degradation in the quality of the polishing or brushing.

[0031] Furthermore, since the oscillation of the polishing or brushing head pads according to the invention is achieved by a pneumatic actuator, the value of the oscillation frequency of the pads can be perfectly controlled and modified if necessary, unlike prior art solutions which use, in particular, return springs to achieve the oscillations of the pads.

[0032] Thus, the polishing or brushing head according to the invention can further improve the efficiency and quality of polishing and brushing materials, in particular hard materials.

[0033] Preferably, the polishing or brushing head is a polishing or brushing head for hard materials, especially natural or artificial, for example in the field of funeral, decoration, roadworks, architectural concrete and building.

[0034] In this description, "hard materials" means mineral-based materials, whether natural or artificial, having a hardness of 1 to 10 Mohs, preferably 1 to 9 Mohs, more preferably 1 to 8 Mohs, such as: - stone, in particular natural stone, especially marble, tufa and granite, and artificial stone, especially concrete; - ceramics, particularly porcelain, earthenware, stoneware and terracotta in general; and - Granite-type composite materials.

[0035] Preferably, the polishing or brushing head extends along a longitudinal axis, preferably perpendicular to the surface of the material to be polished or brushed.

[0036] Preferably, the polishing or brushing head is intended to be driven in rotation around its longitudinal axis, preferably at a rotational speed of 400 to 800 revolutions per minute, preferably by a spindle of a machine tool.

[0037] Preferably, the polishing or brushing head is a polishing head for multi-axis machine tools, especially for 3-axis, 4-axis, 5-axis or 6-axis machine tools.

[0038] In this description, "3-axis machine tool" means that the polishing or brushing head can be moved in translation along each of the 3 axes of a Cartesian coordinate system X, Y and Z.

[0039] In this description, "4-axis machine tool" means that the polishing or brushing head can be moved in translation along each of the 3 axes of a Cartesian coordinate system X, Y and Z and in rotation around an axis parallel to the Z axis, called the C axis.

[0040] In this description, "5-axis machine tool" means that the polishing or brushing head can be moved in translation along each of the 3 axes of a Cartesian coordinate system X, Y and Z, in rotation around an axis parallel to the X axis, called axis A, and in rotation around an axis parallel to the Z axis, called axis C.

[0041] In this description, "6-axis machine tool" means that the polishing or brushing head can be moved in translation along each of the 3 axes of a Cartesian coordinate system X, Y and Z, in rotation around an axis parallel to the X axis, called axis A, in rotation around an axis parallel to the Z axis, called axis C, and in translation along an axis parallel to the longitudinal axis of the spindle.

[0042] Preferably, the second position is opposite the first position.

[0043] The first position and the second position can form an angle between 10° and 60°, preferably between 10° and 50°, more preferably between 10° and 40°, and even more preferably between 20° and 30°.

[0044] Preferably, the pneumatic actuator is configured to act on the shoes to make them oscillate between the first position and the second position, synchronously.

[0045] The pneumatic actuator can be actuated by a pressurized gas, such as for example an inert gas or compressed air, preferably compressed air.

[0046] Pressurized gas, including compressed air, can come from a compressed gas cylinder, such as a compressed air cylinder, or from a compressor.

[0047] The polishing or brushing head can have a number of shoes ranging from 3 to 8, preferably from 3 to 6. For example, the polishing or brushing head has 3 shoes.

[0048] Each shoe may have two external longitudinal edges, parallel to each other, and a fastening element projecting from one of the external longitudinal edges.

[0049] The fastening element may be in the form of a plate.

[0050] Each shoe may have a groove intended to receive or receiving the abrasive tool, in particular a tenon of the abrasive tool, the tenon preferably being made of plastic.

[0051] Preferably, the groove has a width that decreases from the center to the periphery of the polishing or brushing head.

[0052] Preferably, the groove and tenon are of complementary shapes so as to form a dovetail joint.

[0053] Preferably, the abrasive tools are inserted into the shoes from the center to the periphery of the polishing or brushing head, and the centrifugal force generated when rotating the polishing or brushing head around its longitudinal axis helps to keep the abrasive tools in the shoes.

[0054] Preferably, each shoe is made from a single piece.

[0055] The polishing or brushing head may include a body extending along the longitudinal axis of the polishing or brushing head.

[0056] The polishing or brushing head may have a proximal part and a distal part.

[0057] Preferably, the proximal part is intended to be connected to a machine tool, in particular to be fixed to a spindle of a machine tool.

[0058] Preferably, the distal part is intended to come into contact with the surface of the material to be polished or brushed.

[0059] The proximal and distal parts are configured to fit together to form the polishing or brushing head.

[0060] The proximal and distal parts can be mobile relative to each other so as to allow the polishing or brushing head to adapt to the surface defects of the material to be polished or brushed.

[0061] Thus, the polishing or brushing head can be particularly advantageous insofar as it can be adapted to materials with surface defects, i.e. whose surface is not perfectly flat.

[0062] Preferably, the proximal and distal parts are mobile relative to each other by means of a ball joint.

[0063] The proximal part may include a spherical external surface, notably made of steel, and the distal part may include a complementary spherical internal surface, notably made of steel.

[0064] Preferably, the patellar joint is formed by the spherical outer surface of the proximal part and the complementary spherical inner surface of the distal part.

[0065] Thus, the distal part can take: - a neutral position in which its transverse plane is perpendicular to the longitudinal axis of the proximal part, and - an oblique position in which its transverse plane is oblique to the longitudinal axis of the proximal part.

[0066] Preferably, the distal part has a spring configured to allow the distal part to be placed in a neutral position and to allow it to return to the neutral position from the oblique position.

[0067] Preferably, the proximal and distal parts are mobile relative to each other so that the angle formed between the transverse plane of the distal part and the longitudinal axis of the proximal part is between 85° and 95°, preferably between 87° and 93°, more preferably between 88° and 92°.

[0068] The axis of rotation of each shoe can be perpendicular or oblique to the longitudinal axis of the polishing or brushing head.

[0069] The axes of rotation of the hooves can extend in the same plane.

[0070] Preferably, the pneumatic actuator is configured to act on the shoes to make them oscillate between the first position and the second position at an oscillation frequency of 10 to 30 oscillations per minute.

[0071] The pneumatic actuator can be a pneumatic cylinder.

[0072] The pneumatic actuator can be a double-acting pneumatic actuator, in particular a double-acting pneumatic cylinder.

[0073] The use of a double-acting pneumatic actuator, in particular a double-acting pneumatic cylinder, can allow for the control and management of the oscillations of the hooves in both directions, that is, from the first position to the second position, but also from the second position to the first position.

[0074] The pneumatic cylinder may consist of a piston and a plurality of rods.

[0075] The piston may have a ring shape, for example with an outer diameter ranging from 200 mm to 500 mm, an inner diameter ranging from 100 mm to 300 mm and / or a height ranging from 10 mm to 25 mm.

[0076] The rods may have a circular cross-section, for example with a diameter ranging from 10 mm to 25 mm.

[0077] The stems can have a length ranging from 40 mm to 100 mm.

[0078] The pneumatic cylinder can have a number of rods ranging from 3 to 8, preferably from 3 to 6. For example, the pneumatic cylinder has 3 rods.

[0079] Preferably, the pneumatic cylinder has a number of rods that is equal to the number of shoes.

[0080] Each rod of the pneumatic cylinder can have a first end and a second end, opposite to the first end.

[0081] The first end of each rod of the pneumatic cylinder can be connected to the piston of the pneumatic cylinder.

[0082] The second end of each rod of the pneumatic cylinder can be connected to a respective shoe of the plurality of shoes, in particular to the fixing member of a respective shoe of the plurality of shoes, by means of a respective connecting rod.

[0083] The pneumatic cylinder can have a body closed by a bottom and a nose, so as to form a cylinder.

[0084] In this description, "cylinder" means a tube closed at both ends by the bottom and the nose.

[0085] The base and the nose can each have a ring shape.

[0086] The cylinder can be annular in shape.

[0087] The piston of the pneumatic cylinder can be configured to slide inside the cylinder.

[0088] The cylinder can thus ensure the guidance of the piston.

[0089] The pneumatic cylinder may include a rear chamber defining a volume of the cylinder located between the bottom and the piston.

[0090] The pneumatic cylinder may include a front chamber defining a volume of the cylinder located between the nose and the piston.

[0091] The front and rear rooms are preferably isolated from each other.

[0092] The base may include a sealing gasket.

[0093] The nose may include a sealing gasket.

[0094] The piston may include one or more seals, including lip seals.

[0095] The presence of one or more sealing gaskets can make the rear chamber and the front chamber watertight.

[0096] The bottom may include at least one bottom opening allowing gas supply and gas exhaust from the rear chamber, in particular at least one tapped hole.

[0097] The nose may include at least one nose opening allowing for the supply of gas and the exhaust of gas from the front chamber, including at least one tapped hole.

[0098] The polishing or brushing head may have a rear port connected to the bottom port by a rear circuit, the rear port allowing gas supply and gas exhaust from the rear chamber via the rear circuit.

[0099] The polishing or brushing head may have a front port connected to the nose port by a front circuit, the front port allowing gas supply and gas exhaust from the front chamber via the front circuit. [000100] Preferably, the rear orifice and the front orifice are two separate orifices. [000101] Preferably, the rear circuit and the front circuit are two separate circuits. [000102] The pneumatic cylinder can be configured so that, when the rear circuit is supplied with pressurized gas from the rear port, the pressurized gas enters the rear chamber, in particular through the bottom port, the piston slides towards the nose and the rods extend from the cylinder, which rotates the shoes, in particular synchronously, to the first position. The gas in the front chamber is then expelled from the front chamber via the front circuit towards the front port. [000103] The pneumatic cylinder can be configured so that, when the front circuit is supplied with pressurized gas from the front port, the pressurized gas enters the front chamber, in particular through the nose port, the piston slides towards the bottom and the rods retract into the cylinder, which causes rotation, particularly synchronously, of the shoes to the second position. The gas located in the rear chamber is then expelled from the rear chamber via the rear circuit towards the rear port. [000104] Thus, depending on its position within the cylinder, the piston defines the volume of the front chamber and the volume of the rear chamber. [000105] The pneumatic cylinder can be configured to allow simultaneously the supply of pressurized gas to the front chamber via the front circuit and the exhaust of gas from the rear chamber via the rear circuit, then simultaneously the supply of pressurized gas to the rear chamber via the rear circuit and the exhaust of gas from the front chamber via the front circuit, and so on, so as to oscillate the shoes, in particular synchronously, between the first position and the second position. [000106] The proximal part may include a pin fixing system. [000107] The proximal part may include the front opening and the rear opening. [000108] The proximal part may include in its center a watering channel extending along the longitudinal axis of the proximal part. [000109] The spray channel can allow a pressurized spray fluid, in particular water or another lubricant, preferably water, to be brought to the surface of the material to be polished or brushed. [000110] The distal part may include the pneumatic actuator, in particular the pneumatic cylinder. [000111] The distal part may comprise a plurality of hooves. [000112] The pneumatic actuator, in particular the pneumatic cylinder, in particular the movement of the piston of the pneumatic cylinder, can be controlled by at least one valve, preferably located on the machine tool. [000113] Thus, the polishing or brushing head is preferably valve-free. This can minimize the mass and size of the polishing or brushing head. [000114] Preferably, the abrasive tools are segments. [000115] Abrasive tools can be polishing or brushing abrasive tools. [000116] Abrasive polishing tools are configured to allow polishing of the material, such as, for example, a mirror polish (also called a high-gloss polish). Abrasive polishing tools may be based on diamond or synthetic silicon carbide. They can have a grain size number between 30 and 1200. For example, a high grain size number, corresponding to an extremely fine grain, called felt, allows for a mirror polishing finish. [000117] The abrasive brushing tools are configured to allow the material to be brushed, and in particular to allow the material surface to be textured, such as for example a leather effect. The abrasive brushing tools may be nylon-based brushes and abrasive aggregates. [000118] Preferably, the polishing or brushing head is made of aluminum or an aluminum alloy. [000119] For example, the shoes of the polishing or brushing head are made of aluminum or an aluminum alloy. [000120] For example, the pneumatic actuator of the polishing or brushing head, in particular the pneumatic cylinder of the polishing or brushing head, is made of aluminum or an aluminum alloy. [000121] The use of aluminium or an aluminium alloy can contribute to minimizing the mass of the polishing or brushing head. [000122] Preferably, the polishing or brushing head has a mass less than or equal to 20 kg, preferably less than or equal to 15 kg. [000123] In comparison, a conventional polishing or brushing head “BS3C” from THIBAUT has a mass of 68 kg and a conventional polishing or brushing head “BS5C” from THIBAUT has a mass of 104 kg. [000124] The mass values ​​indicated above correspond to the mass of the polishing or brushing head with its spindle attachment system. [000125] The polishing or brushing head may have a height less than or equal to 250 mm, preferably less than or equal to 225 mm, more preferably less than or equal to 200 mm. [000126] In comparison, a conventional polishing or brushing head “BS3C” or “BS5C” from the company THIBAUT has a height of 319 mm. [000127] The height values ​​indicated above correspond to the height of the visible part of the polishing or brushing head when the latter is fixed to a spindle of a machine tool. [000128] The polishing or brushing head is therefore particularly advantageous because it can be used on small machine tools and / or with a low-power spindle motor. This is due to the reduced size and mass of the polishing or brushing head. [000129] Machine tool [000130] The invention also relates, according to another aspect, to a machine tool, in particular a multi-axis machine tool, comprising: - a brooch, - at least one polishing or brushing head as defined above. [000131] The machine tool according to the invention is particularly advantageous insofar as it can allow an improvement in the efficiency and quality of polishing or brushing, due to the use of a polishing or brushing head as defined above. [000132] The machine tool may be intended for polishing or brushing hard materials, in particular in an automated or semi-automated manner. [000133] The spindle can extend along a longitudinal axis. [000134] The machine tool may include a spindle motor, in particular an electric one. [000135] The spindle motor can be configured to drive the spindle in rotation around its longitudinal axis, for example at a rotational speed ranging from 400 to 800 revolutions per minute. [000136] The spindle motor may have a power less than or equal to 25 kW, in particular less than or equal to 20 kW. [000137] In one embodiment, the spindle motor has a power ranging from 5 kW to 25 kW, in particular from 5 kW to 20 kW. [000138] The machine tool is thus particularly advantageous insofar as it can include a spindle motor with lower power than a spindle motor of a conventional machine tool, and therefore have a reduced footprint. This is due to the reduced size and mass of the polishing or brushing head of the machine tool according to the invention compared to a conventional polishing or brushing head. [000139] The machine tool may have a width between 400 cm and 800 cm, a length between 400 cm and 2000 cm and / or a height between 200 cm and 450 cm. [000140] The machine tool is thus particularly advantageous insofar as it can be compact, due to the reduced size and mass of the polishing or brushing head of the machine tool according to the invention compared to a conventional polishing or brushing head. [000141] The machine tool may include a gantry, preferably extending horizontally, configured to support the spindle, and in particular the spindle motor. [000142] The polishing or brushing head can extend along a longitudinal axis. [000143] The spindle can be configured to receive and drive the polishing or brushing head in rotation around its longitudinal axis, for example at a rotational speed of 400 to 800 revolutions per minute. [000144] The machine tool may include a plate, preferably horizontal, configured to receive the material to be polished or brushed. [000145] The machine tool can be multi-axis. [000146] The multi-axis machine tool can be a 3-axis, 4-axis, 5-axis or 6-axis machine tool. [000147] The machine tool may include a plurality of polishing or brushing heads as defined above, in particular a number of polishing or brushing heads ranging from 5 to 10, preferably ranging from 5 to 8. [000148] When the machine tool has a plurality of polishing or brushing heads, the abrasive tools of each of the polishing heads may have different grain size numbers. [000149] When the machine tool has a plurality of polishing or brushing heads, the spindle can be configured to receive and drive in rotation each polishing or brushing head around its longitudinal axis, successively, so that the abrasive tools which are successively brought into contact with the surface of the material to be polished or brushed have an increasing grain size number. [000150] This can allow for increasingly finer polishing or brushing. [000151] When the machine tool has a plurality of polishing or brushing heads, the machine tool may have at least one magazine in which the polishing or brushing heads are stored. [000152] The machine tool may include a system configured to allow the loading of a polishing or brushing head stored in the magazine onto the spindle. [000153] The machine tool may include a system configured to allow the polishing or brushing head loaded on the spindle to be unloaded into the magazine. [000154] The machine tool may include at least one other tool besides a polishing or brushing head as defined above, for example a sawing disc, a drilling bit, a milling cutter, etc. Such a machine tool is then a multi-function machine tool. [000155] The machine tool may include at least one valve configured to control the pneumatic actuator, in particular the pneumatic cylinder, in particular the movement of the piston of the pneumatic cylinder, of the polishing or brushing head, and thus control the oscillations of the shoes of the polishing or brushing head. [000156] The valve can be a mechanically, electrically, pneumatically, or electropneumatically controlled valve. [000157] Preferably, the valve is a proportional valve, in particular electrically or electropneumatically controlled. [000158] In a first embodiment, the machine tool includes a single valve configured to control the pneumatic actuator, in particular the pneumatic cylinder, in particular the movement of the piston of the pneumatic cylinder, of the polishing or brushing head, and thus control the oscillations of the shoes of the polishing or brushing head. [000159] Preferably, said single valve has at least four separate ports, including one port for supplying gas to the rear chamber, one port for exhausting gas from the rear chamber, one port for supplying gas to the front chamber and one port for exhausting gas from the front chamber of the pneumatic cylinder of the polishing or brushing head. [000160] Thus, in this first embodiment, said single valve is preferably connected to the rear chamber via the rear circuit and to the front chamber via the front circuit. [000161] For example, said single valve is of type 5 / 2. [000162] In a second embodiment, the machine tool includes two valves configured to control the pneumatic actuator, in particular the pneumatic cylinder, in particular the movement of the piston of the pneumatic cylinder, of the polishing or brushing head, and thus control the oscillations of the shoes of the polishing or brushing head. [000163] Preferably, one of the two valves has at least two separate ports, including one port for supplying gas to the rear chamber and one port for exhausting gas from the rear chamber of the pneumatic cylinder of the polishing or brushing head. [000164] Preferably, the other valve has at least two separate ports, including one port for supplying gas to the front chamber and one port for exhausting gas from the front chamber of the pneumatic cylinder of the polishing or brushing head. [000165] Thus, in this second embodiment, one of the two valves is preferably connected to the rear chamber via the rear circuit and the other valve is preferably connected to the front chamber via the front circuit. [000166] For example, each of the two valves is of type 3 / 2. [000167] It is advantageous for the valve(s) to be located on the machine tool and not on the polishing or brushing head. Indeed, as mentioned above, this can minimize the mass and size of the polishing or brushing head. [000168] Furthermore, when the machine tool has a plurality of polishing or brushing heads, the machine tool's valve(s) can then be used to control the pneumatic actuator, in particular the pneumatic cylinder, specifically the movement of the pneumatic cylinder piston, of each of the polishing or brushing heads. This can thus minimize the number of valves required. [000169] The machine tool may include a numerical control system. [000170] The numerical control system can be configured to control the movements of the polishing or brushing head along the 3 axes, 4 axes, 5 axes or 6 axes of the machine tool. [000171] The digital control system can be configured to control the valve(s). [000172] The control of the valve or valves by the digital control system can allow the oscillation frequency of the shoes to be controlled between the first position and the second position. [000173] This can even allow independent control of the rotation speed of the shoes from the first position to the second position and the rotation speed of the shoes from the second position to the first position, if necessary. [000174] Polishing or brushing method [000175] The invention also relates, according to another aspect, to a polishing or brushing method comprising the steps of: a) having a polishing or brushing head as defined above, the polishing or brushing head comprising a plurality of pads, each pad receiving an abrasive tool intended to come into contact with the surface of a material to be polished or brushed, b) rotating the polishing or brushing head around its longitudinal axis, in particular continuously, in particular by means of a spindle of a machine tool, c) oscillating each pad, in particular continuously or discontinuously, around its axis of rotation between a first position and a second position, different from the first position, in particular by means of the pneumatic actuator, d) bringing the pads of the polishing or brushing head into contact with the surface of the material to be polished or brushed. [000176] Preferably, step d) is implemented after steps a), b) and c). [000177] Preferably, step c) is implemented so as to oscillate the shoes synchronously between the first position and the second position. Brief description of the figures [000178] The following description, with reference to the accompanying drawings, given by way of non-limiting examples, will clearly explain what the invention consists of and how it can be implemented. In the accompanying figures: [000179] [fig. 1] Figure 1 schematically and in perspective represents an example of a polishing or brushing head according to the invention with the shoes in the first position; [000180] [fig. 2] Figure 2 is a view analogous to figure 1 with the hooves in the median position; [000181] [fig. 3] Figure 3 is a view analogous to figure 1 with the hooves in the second position; [000182] [fig. 4] Figure 4 is a schematic and perspective longitudinal section, according to BB, of an example of a polishing or brushing head according to the invention with the shoes in the middle position; [000183] [fig. 5] Figure 5 represents a schematic and perspective longitudinal section, along DD, of an example of a polishing or brushing head according to the invention with the shoes in the second position; [000184] [fig. 6] Figure 6 represents a schematic and perspective longitudinal section, according to EE, of an example of a polishing or brushing head according to the invention with the shoes in the first position; [000185] [fig. 7a] Figure 7a represents a schematic and perspective longitudinal section of an example of a polishing or brushing head according to the invention with the shoes in the second position; [000186] [fig. 7b] Figure 7b represents another schematic and perspective longitudinal section of the polishing or brushing head of figure 7a; [000187] [fig. 8a] Figure 8a represents a schematic and perspective longitudinal section of an example of a polishing or brushing head according to the invention with the shoes in the first position; [000188] [fig. 8b] Figure 8b represents another longitudinal, schematic and perspective section of the polishing or brushing head of figure 8a; [000189] [fig. 9] Figure 9 is a schematic, perspective, longitudinal section view of an example of a polishing or brushing head according to the invention with the shoes in a median position, passing through the center of the polishing or brushing head; [000190] [fig. 10] Figure 10 is a view analogous to figure 9; [000191] [fig. 11] Figure 11 schematically and in perspective represents an example of a polishing or brushing head according to the invention with the shoes in the middle position; [000192] [fig. 12] Figure 12 is a view analogous to figure 11 with the abrasive tools received in the shoes; [000193] [fig. 13] Figure 13 represents, schematically and in perspective, a detail of a shoe receiving an abrasive tool; [000194] [fig. 14] Figure 14 represents an exploded view, schematically and in perspective, of an example of a polishing or brushing head according to the invention with the shoes in the middle position; [000195] [fig. 15] Figure 15 is a view analogous to figure 14, in longitudinal section, schematic and in perspective, passing through the center of the polishing or brushing head; [000196] [fig. 16] Figure 16 represents a longitudinal section, schematically and in perspective, of an example of a polishing or brushing head according to the invention with the shoes in the median position and with the distal part in the neutral position, passing through the center of the polishing or brushing head; [000197] [fig. 17] Figure 17 is a view analogous to figure 16 with the distal part in an oblique position; [000198] [fig. 18] Figure 18 represents a schematic and perspective front view of an example of a polishing or brushing head according to the invention; [000199] [fig. 19] Figure 19 represents a schematic and perspective front view of a polishing or brushing head according to the prior art; [000200] [fig. 20] Figure 20 represents, schematically and in perspective, an example of a machine tool according to the invention; [000201] [fig. 21] Figure 21 represents, schematically and in perspective, a detail of the machine tool of figure 20; [000202] [fig. 22] Figure 22 schematically and in perspective represents another detail of the machine tool of figure 20; and [000203] [fig. 23] Figure 23 is a view analogous to Figure 22, with the spindle fixing system of the polishing or brushing head shown in longitudinal section. Description of method(s) of implementation [000204] In the figures, and unless otherwise specified, identical elements shall bear the same reference symbols. [000205] An example of a polishing or brushing head 1 for a machine tool according to the invention is shown in figures 1 to 3. [000206] The polishing or brushing head 1 for machine tool, shown in Figures 1 to 3, comprises: - a plurality of shoes 2, each shoe 2 receiving an abrasive tool 3 intended to come into contact with the surface of a material to be polished or brushed, each shoe 2 being movable in rotation about an axis of rotation R between a first position P1 and a second position P2, different from the first position P1, and - at least one pneumatic actuator 4 configured to act on each shoe 2 to make it oscillate around its axis of rotation R between the first position P1 and the second position P2. [000207] In figures 1 to 3, part of the polishing and brushing head 1 has been shown in transparency, so as to be able to represent the pneumatic actuator 4. [000208] Figure 1 shows the hooves in the first position P1. Figure 3 shows the hooves in the second position P2. [000209] When the shoes oscillate between the first position P1 (figure 1) and the second position P2 (figure 3), they pass through a median position, shown in figure 2. [000210] As illustrated in figures 1 and 3, the second position P2 is opposite the first position P1. [000211] The angle ai, shown in figure 1, allows us to define the first position P1 with respect to the median position. [000212] Angle 02, shown in figure 3, allows us to define the second position P2 with respect to the median position. [000213] Angle ai and angle 02 are preferably equal. [000214] The angle ai and the angle 02 can each be included, in absolute value, between 5° and 30°, preferably between 5° and 25°, more preferably between 5° and 20°, and even more preferably between 10° and 15°. [000215] In one embodiment, eu = 02 = 12.5°. Thus, in this embodiment, each shoe can be driven in rotation around its axis of rotation R so as to oscillate between -12.5° and +12.5° with respect to its median position (which corresponds to 0°), so that the first position and the second position form an angle of 25°. [000216] As illustrated in figures 1 to 3, the pneumatic actuator 4 is thus configured to act on the shoes 2 to make them oscillate, synchronously, between the first position P1 (represented in figure 1) and the second position P2 (represented in figure 2), like a pendulum. [000217] As illustrated in Figures 1 to 3, the polishing or brushing head 1 extends along a longitudinal axis L, preferably perpendicular to the surface of the material to be polished or brushed. The polishing or brushing head 1 is intended to be driven in rotation about its longitudinal axis L. [000218] In the example shown in Figures 1 to 3, the polishing or brushing head 1 has 3 shoes. However, the polishing or brushing head 1 can have a higher number of shoes, for example from 4 to 8 shoes, in particular from 4 to 6 shoes. [000219] As illustrated in figures 1 to 10, the pneumatic actuator 4 is for example a pneumatic cylinder, in particular a double-acting pneumatic cylinder. [000220] The pneumatic cylinder comprises a piston 4a, of annular shape, and a plurality of rods 4b, of circular cross-section. [000221] The pneumatic cylinder has a number of rods 4b which is equal to the number of shoes 2. Thus, the pneumatic cylinder here has three rods 4b. [000222] Each rod 4b of the pneumatic cylinder has a first end 10 and a second end 11, opposite the first end 10. [000223] The first end 10 of each rod 4b of the pneumatic cylinder is connected to the piston 4a of the pneumatic cylinder. [000224] The second end 1 of each rod 4b of the pneumatic cylinder is connected to a respective shoe 2 of the plurality of shoes 2, in particular to the member of fixing 2b of a respective shoe 2 of the plurality of shoes 2, by means of a respective connecting rod 12. [000225] The pneumatic cylinder comprises a body 13 closed by a bottom 14 and a nose 15, so as to form a cylinder, i.e. a tube closed at its two ends by the bottom 14 and the nose 15, of annular shape. [000226] The bottom 14 and the nose 15 each have a ring shape. [000227] The piston 4a of the pneumatic cylinder is configured to slide inside the cylinder. [000228] The pneumatic cylinder includes a rear chamber 16 defining a volume of the cylinder located between the bottom 14 and the piston 4a. [000229] The pneumatic cylinder includes a front chamber 17 defining a volume of the cylinder located between the nose 15 and the piston 4a. [000230] The front chamber 17 and the rear chamber 16 are each watertight. [000231] As illustrated in figures 7 and 8, the bottom 14 has at least one bottom orifice 18 allowing the supply of gas and the exhaust of gas from the rear chamber 16, in particular at least one tapped hole, and the nose 15 has at least one nose orifice 19 allowing the supply of gas and the exhaust of gas from the front chamber 17, in particular at least one tapped hole. [000232] The polishing or brushing head 1 has a rear orifice 23 connected to the bottom orifice 18 by a rear circuit 21, the rear orifice 23 allowing the supply of gas and the exhaust of gas from the rear chamber 16 via the rear circuit 21. [000233] The polishing or brushing head 1 has a front orifice 22 connected to the nose orifice 19 by a front circuit 20, the front orifice 22 allowing the supply of gas and the exhaust of gas from the front chamber 17 via the front circuit 20. [000234] The rear orifice 23 and the front orifice 22 are two separate orifices. [000235] The rear circuit 21 and the front circuit 20 are two separate circuits. [000236] As illustrated in Figures 7a and 7b, the pneumatic cylinder is configured so that, when the front circuit 20 is supplied with pressurized gas from the front port 22, the pressurized gas enters the front chamber 17, in particular through the nose port 19 (the movement of the pressurized gas is represented by the arrows in Figure 7a), the piston 4a slides towards the bottom 14 and the rods 4b retract into the cylinder, which causes rotation, in particular of In a synchronous manner, the shoes 2 move to the second position P2 (the movement of the piston 4a, the rods 4b and the shoes 2 are represented by the arrows in Figure 7b). The gas located in the rear chamber 16 is then expelled from the rear chamber 16 via the rear circuit 21 towards the rear port 23. [000237] As illustrated in Figures 8a and 8b, the pneumatic cylinder is configured so that, when the rear circuit 21 is supplied with pressurized gas from the rear port 23, the pressurized gas enters the rear chamber 16, notably through the bottom port 18 (the movement of the pressurized gas is represented by the arrows in Figure 8a), the piston 4a slides towards the nose 15 and the rods 4b extend from the cylinder, which rotates, notably synchronously, the shoes 2 to the first position P1 (the movement of the piston 4a, the rods 4b and the shoes 2 are represented by the arrows in Figure 8b). The gas in the front chamber 17 is then expelled from the front chamber 17 via the front circuit 20 towards the front port 22. [000238] Thus, depending on its position within the cylinder, the piston 4a defines the volume of the front chamber 17 and the volume of the rear chamber 16. [000239] The pneumatic cylinder is configured to allow simultaneously the supply of pressurized gas to the front chamber 17 via the front circuit 20 and the exhaust of gas from the rear chamber 16 via the rear circuit 21, then simultaneously the supply of pressurized gas to the rear chamber 16 via the rear circuit 21 and the exhaust of gas from the front chamber 17 via the front circuit 20, and so on, so as to oscillate the shoes 2, in particular synchronously, between the first position P1 and the second position P2. [000240] Figures 11 and 12 show an example of a polishing or brushing head 1 without the abrasive tools 3 (Figure 11) and with the abrasive tools 3 received in the shoes 2 (Figures 12 and 13). [000241] In the example illustrated in figures 11 to 13, each shoe 2 has two external longitudinal edges 2a, parallel to each other, and a fastening member 2b projecting on one of the external longitudinal edges 2a. [000242] The fastening member 2b is in the form of a plate. [000243] Each shoe 2 has a groove 2c intended to receive or receiving the abrasive tool 3, in particular a tenon 3a of the abrasive tool 3. For example, the tenon 3a is made of plastic material. [000244] The groove 2c and the tenon 3a are of complementary shapes so as to form a dovetail joint. [000245] The tenon 3a is connected to an abrasive material 3b to form the abrasive tool 3. [000246] The groove 2c has a width that decreases from the center to the periphery of the polishing or brushing head 1. This allows the abrasive tools 3 to be inserted into the shoes 2 from the center to the periphery of the polishing or brushing head 1. The centrifugal force generated when the polishing or brushing head 1 is rotated about its longitudinal axis L helps to keep the abrasive tools 3 in the shoes 2. [000247] Figures 14 and 15 show an example of a polishing or brushing head 1, in exploded view, in perspective (figure 14) and according to a longitudinal section passing through the center of the polishing or brushing head 1 (figure 15). [000248] In the example illustrated in figures 14 and 15, the polishing or brushing head 1 comprises a proximal part 40 and a distal part 30. [000249] The proximal part 40 is intended to be connected to a machine tool, in particular to a spindle of a machine tool, and the distal part 30 is intended to come into contact with the surface of the material to be polished or brushed. [000250] The proximal part 40 and the distal part 30 are configured to fit together to form the polishing or brushing head 1. [000251] The proximal part 40 and the distal part 30 are movable relative to each other so as to allow the polishing or brushing head 1 to adapt to the surface defects of the material to be polished or brushed. [000252] In the example illustrated in figures 14 and 15, the proximal part 40 and the distal part 30 are mobile relative to each other by means of a ball joint. [000253] The proximal part 40 has an external spherical surface 41, in particular made of steel, and the distal part 30 has a complementary internal spherical surface 31, in particular made of steel. [000254] The ball joint is formed by the external spherical surface 41 of the proximal part 40 and the complementary internal spherical surface 31 of the distal part 30. [000255] Figures 16 and 17 show an example of a polishing or brushing head 1, along a longitudinal section passing through the center of the polishing or brushing head 1. [000256] As illustrated in Figures 16 and 17, the distal portion 30 can take: - a neutral position, shown in Figure 16, in which its transverse plane P is perpendicular to the longitudinal axis L of the proximal part 40, and - an oblique position in which its transverse plane P is oblique with respect to the longitudinal axis L of the proximal part 40. [000257] The movement of the transverse plane P of the distal part 30 necessary for the passage from the neutral position to the oblique position is represented by the arrow in figure 17. [000258] The angle 03, shown in figure 16, allows us to define the neutral position that the distal part 30 can take. In this neutral position, the transverse plane P of the distal part 30 is perpendicular to the longitudinal axis L of the proximal part 40, so that 03 = 90°. [000259] The angle eu, shown in figure 17, allows us to define the oblique position that the distal part 30 can take. In this oblique position, the transverse plane P of the distal part 30 is oblique with respect to the longitudinal axis L of the proximal part 40, so that 85° < eu < 90°, preferably 87° < or < 90°, more preferably 88° < or < 90°. [000260] As illustrated in figures 15 to 17, the distal part 30 has a spring 32 configured to allow the distal part 30 to be placed in the neutral position and to allow it to return to the neutral position from the oblique position. [000261] As illustrated in figures 16 and 17, the axis of rotation R of each shoe 2 can be perpendicular or oblique to the longitudinal axis L of the polishing or brushing head 1, in particular depending on the neutral or oblique position taken by the distal part 30. [000262] As illustrated in figures 14 and 15, the proximal part 40 includes a pin-fixing system 42. [000263] The proximal part 40 includes the front opening 22 and the rear opening 23. [000264] The proximal part 40 has in its center a watering channel 43 extending along the longitudinal axis L of the proximal part 40. Tl [000265] The watering channel 43 allows a pressurized watering fluid, in particular water or another lubricant, preferably water, to be brought to the surface of the material to be polished or brushed. [000266] The distal part 30 includes the pneumatic actuator 4, in particular the pneumatic cylinder. [000267] The distal part 30 comprises the plurality of hooves 2. [000268] An example of a polishing and brushing head 1 according to the invention is shown in Figure 18, and a prior art polishing or brushing head, namely a “BS3C” type head from THIBAUT, is shown, at the same scale, in Figure 19. [000269] The polishing or brushing head 1 according to the invention has in this example a height of 196 mm, whereas the polishing or brushing head of the prior art has a height of 319 mm (the height values ​​indicated above correspond to the height of the visible part of the polishing or brushing head when the latter is fixed to a spindle of a machine tool). [000270] An example of machine tool 100 according to the invention is shown in Fig. 20. [000271] The machine tool 100, shown in Figure 20, comprises: - a 101 pin, - a plurality of polishing or brushing heads 1 according to the invention. [000272] The machine tool 100 is intended for polishing or brushing hard materials, in particular in an automated or semi-automated manner. [000273] As illustrated in figures 20, 22 and 23, the machine tool 100 includes a spindle motor 102, in particular an electric one. [000274] In the example of Figure 20, the spindle 101 and the spindle motor 102 are protected by a housing 200. [000275] The spindle motor 102 is configured to drive the spindle 101 in rotation around its longitudinal axis L. [000276] In the example illustrated in Figure 20, the machine tool has a width L1 between 400 cm and 500 cm, a length L2 between 550 cm and 650 cm and / or a height H between 200 cm and 400 cm. [000277] The machine tool includes a gantry 103, preferably extending horizontally, configured to support the housing 200, the spindle 101, and the spindle motor 102. [000278] The machine tool includes a motor 300, in particular an electric motor, configured to drive in translation the housing 200, the spindle 101, and the spindle motor 102 along the gantry 103. [000279] In the example of figure 20, the motor 300 is fixed on the casing 200. [000280] The machine tool may include a plate 104, preferably horizontal, configured to receive the material to be polished or brushed. [000281] The machine tool 100 is a multi-axis machine tool, in particular with 3 axes, 4 axes, 5 axes or 6 axes. [000282] In the example illustrated in Figure 20, the machine tool has 10 polishing or brushing heads 1. This number can obviously be different. Indeed, the machine tool 100 can have between 5 and 10, in particular between 5 and 8, polishing or brushing heads 1. [000283] The abrasive tools 3 of each of the polishing or brushing heads 1 may have different grain size numbers. [000284] The spindle 101 is configured to receive and drive in rotation each polishing or brushing head 1 around its longitudinal axis L, successively, so that the abrasive tools 3 which are successively brought into contact with the surface of the material to be polished or brushed have an increasing grain size number. [000285] This can allow for increasingly finer polishing or brushing. [000286] The machine tool 100 includes a magazine 105 in which the polishing or brushing heads 1 are stored. [000287] The machine tool 100 includes a system configured to allow the loading of a polishing or brushing head 1 stored in the magazine 105 onto the spindle 101. [000288] The machine tool 100 includes a system configured to allow the unloading of the polishing or brushing head 1 loaded onto the spindle 101 into the magazine 105. [000289] The machine tool includes at least one valve 106 configured to control the pneumatic actuator 4, in particular the pneumatic cylinder, in in particular the movement of the piston 4a of the pneumatic cylinder, of the polishing or brushing head 1, and thus control the oscillations of the shoes 2 of the polishing or brushing head 1. [000290] The valve 106 can be a proportional valve, in particular electrically or electropneumatically controlled. [000291] In the example of Figure 20, the valve 106 is protected by the housing 200. [000292] The machine tool 100 includes a numerical control system 107. [000293] The numerical control system 107 is configured to control the movements of the polishing or brushing head 1 along the 3 axes, 4 axes, 5 axes or 6 axes of the multi-axis machine tool 100. [000294] The digital control system 107 is configured to control the valve(s).

Claims

Demands

1. Polishing or brushing head (1) for a machine tool comprising: - a plurality of shoes (2), each shoe (2) being intended to receive or receiving an abrasive tool (3) intended to come into contact with the surface of a material to be polished or brushed, each shoe (2) being movable in rotation about an axis of rotation (R) between a first position (P1) and a second position (P2), different from the first position (P1), and - at least one pneumatic actuator (4) configured to act on each shoe (2) to make it oscillate around its axis of rotation (R) between the first position (P1) and the second position (P2).

2. Polishing or brushing head (1) according to claim 1, the pneumatic actuator (4) being configured to act on the shoes (2) to make them oscillate between the first position (P1) and the second position (P2), in a synchronous manner.

3. Polishing or brushing head (1) according to claim 1 or 2, the polishing or brushing head (1) extending along a longitudinal axis (L), and the axis of rotation (R) of each shoe (2) being perpendicular or oblique to the longitudinal axis (L) of the polishing or brushing head (1).

4. Polishing or brushing head (1) according to any one of the preceding claims, the pneumatic actuator (4) being a pneumatic cylinder.

5. Polishing or brushing head (1) according to any one of the preceding claims, the pneumatic actuator (4) being a double-acting pneumatic actuator, in particular a double-acting pneumatic cylinder.

6. Polishing or brushing head (1) according to claim 4 or 5, the pneumatic cylinder (4) comprising a piston (4a) and a plurality of rods (4b).

7. Polishing or brushing head (1) according to claim 6, each rod (4b) of the pneumatic cylinder having a first end (10) and a second end (11), opposite the first end (10) of each rod (4b) of the pneumatic cylinder being connected to the piston (4a) of the pneumatic cylinder, and the second end (11) of each rod (4b) of the cylinder pneumatic being connected to a respective shoe (2) of the plurality of shoes (2) by means of a respective connecting rod (12).

8. Polishing or brushing head (1) according to claim 6 or 7, the pneumatic cylinder comprising a body (13) closed by a bottom (14) and a nose (15), so as to form a cylinder, in particular of annular shape, the piston (4a) of the pneumatic cylinder being configured to slide inside the cylinder.

9. Polishing or brushing head (1) according to claim 8, the pneumatic cylinder comprising a rear chamber (16) defining a volume of the cylinder located between the bottom (14) and the piston (4a) and a front chamber (17) defining a volume of the cylinder located between the nose (15) and the piston (4a).

10. Polishing or brushing head (1) according to claim 9, the bottom (14) having at least one bottom orifice (18) allowing the supply of gas and the exhaust of gas from the rear chamber (16), in particular at least one tapped hole, and the nose (15) having at least one nose orifice (19) allowing the supply of gas and the exhaust of gas from the front chamber (17), in particular at least one tapped hole.

11. Polishing or brushing head (1) according to claim 10, the polishing or brushing head (1) comprising: - a rear port (23) connected to the bottom port (18) by a rear circuit (21), the rear port (23) allowing the supply of gas and the exhaust of gas from the rear chamber (16) via the rear circuit (21), and - a front orifice (22) connected to the nose orifice (19) by a front circuit (20), the front orifice (22) allowing the supply of gas and the exhaust of gas from the front chamber (17) via the front circuit (20).

12. Polishing or brushing head (1) according to claim 11, the pneumatic cylinder being configured so that, when the rear circuit (21) is supplied with pressurized gas from the rear port (23), the pressurized gas enters the rear chamber (16), the piston (4a) slides towards the nose (15) and the rods (4b) come out of the cylinder, which drives the shoes (2) into rotation, in particular synchronously, to the first position (P1), the gas in the front chamber (17) then being expelled from the front chamber (17) via the front circuit (20) towards the front port (22).

13. Polishing or brushing head (1) according to claim 11 or 12, the pneumatic cylinder being configured such that, when the circuit The front (20) is supplied with pressurized gas from the front port (22), the pressurized gas enters the front chamber (17), the piston (4a) slides towards the bottom (14) and the rods (4b) enter the cylinder, which causes the shoes (2) to rotate, in particular synchronously, to the second position (P2), the gas located in the rear chamber (16) then being expelled from the rear chamber (16) via the rear circuit (21) towards the rear port (23).

14. Polishing or brushing head (1) according to any one of claims 11 to 13, the pneumatic cylinder being configured to allow simultaneously the supply of pressurized gas to the front chamber (17) via the front circuit (20) and the exhaust of gas from the rear chamber (16) via the rear circuit (21), then simultaneously the supply of pressurized gas to the rear chamber (16) via the rear circuit (21) and the exhaust of gas from the front chamber (17) via the front circuit (20), and so on, so as to oscillate the shoes (2), in particular synchronously, between the first position (P1) and the second position (P2).

15. Machine tool (100) comprising: - a pin (101), - at least one polishing or brushing head (1) according to any one of claims 1 to 14.

16. A polishing or brushing method comprising the steps of: a) having a polishing or brushing head (1) according to any one of claims 1 to 14, the polishing or brushing head (1) having a plurality of pads (2), each pad (2) receiving an abrasive tool (3) intended to come into contact with the surface of a material to be polished or brushed, b) rotating the polishing or brushing head (1) about its longitudinal axis (L), c) oscillating each pad (2) about its axis of rotation (R) between a first position (P1) and a second position (P2), different from the first position (P1), d) bringing the pads (2) of the polishing or brushing head (1) into contact with the surface of the material to be polished or brushed.

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