FR2755744A1 - X-Y translation table - Google Patents

Abstract

The table (1) includes a fix base (2) coupled to a mobile support (3) through a mechanism (4). Two actuators (5,6) are attached to the base for moving the support along two perpendicular directions (X,Y). Two guiding rails (7,8) attached to the base define the two directions (X,Y). The support is provided with three guiding rails (9,10,11) fixed under the support and cooperating with the actuating mechanism.

Description

The present invention relates to a workpiece support device capable of moving in first and second directions, orthogonal to one another.

Such a device is commonly designated by the expression "X-Y translation table", which will also be used, if necessary, below.

Various devices of this type are known, in which, generally, two elements are superimposed, one ensuring displacement in a first direction, and the other in the second direction orthogonal to the first. Such devices generally suffer from a lack of precision, linked to the structural dissociation between the two movements, the defects of which are, moreover, liable to add up. In addition, in maximum stroke, the known translation tables can be subjected to a significant deflection because their lift area can then be reduced substantially to a "point". In addition, the moving masses are important. In addition, the measuring devices are not concurrent with the measuring point, which generates the so-called ABBE error.

The object of the present invention is to avoid these drawbacks.

To this end, the workpiece support device, capable of moving in first (X) and second (Y) directions, orthogonal to one another, is remarkable, according to the invention, in that it comprises - a fixed base, - a movable workpiece support plate, - first and second motor means, intended to move
cer said movable plate relative to said fixed base,
following respectively the direction (X) and the direction
(Y), and fixed on said base, and - connecting means, disposed between said fixed base and
said movable platform, capable of ensuring, through the inter
of said first and second motor means, the
piloting of said movable platform, in the directions (X)
and (Y), relative to said fixed base.

Thus, such an arrangement allows piloting, in both directions (X) and (Y), of the translation table by acting on an intermediate plane between the fixed base and the movable plate, the motor means, fixed relative to a given reference frame, moreover ensuring the precision of the displacements, and the symmetry and the rigidity of the assembly, as will be seen in more detail below.

Preferably, said connecting means comprise, on the one hand, first guide rails, fixed on said base, and second guide rails, fixed on said movable plate and oriented, respectively, in the directions (X) and ( Y), and, on the other hand, carriages, connecting, in pairs, said rails, each carriage connecting rails carried one by said base and the other by said movable plate.

In particular, according to a first embodiment of the device of the invention, said guide rails can be produced in the form of bars of quadratic cross section, while said carriages can be produced in the form of pads of U cross section assembled in pairs back on the back and in two orthogonal directions.

Advantageously, two guide rails are fixed on the upper face of said base along, respectively, the directions (X) and (Y) and three guide rails are fixed on the underside of said movable plate, three said intermediate parts connecting said rails two together.

According to another embodiment of the device of the invention, said connecting means comprise, on the one hand, two first U-shaped cross-section guide rails, provided on said base, and two second cross-section guide rails in U-shaped, provided on said movable plate and, on the other hand, two carriages in the form of plates, each of which has two pads in the form of ribs of quadratic cross section, fixed on either side of said piece, each rib being able to engage and slide in the corresponding rail.

According to a first variant of this other embodiment, the two said first guide rails are provided on the upper face of said base, being arranged 900 from one another in the direction (X) or (Y) respectively. , and the two said second guide rails are provided on the underside of said movable plate, being arranged 900 from each other in the direction (X) or (Y), respectively, and the pads of each of said parts intermediaries are arranged 900 from each other to engage, respectively, in a guide rail provided on said base and a guide rail provided on said movable plate, the latter rails being orthogonal to one other.

According to a second variant, the two said first guide rails are provided on the upper face of said base by being arranged parallel to one another, and at an angle (a) with one or the other of the directions (X) and (Y), and the pads of each of said intermediate parts are arranged, with respect to each other, at an angle such that they can engage in their respective guide rails of said base and said movable plate.

Preferably, said angle (a) is at least substantially equal to 450.

Furthermore, each of said motorized drives is advantageously fixed to said base parallel to the respective guide rail provided on said base.

The figures of the appended drawing will make it clear how the invention can be implemented. In these figures, identical references designate similar elements.

Figure 1 is a schematic exploded perspective view of a first embodiment of the workpiece support device according to the invention.

Figure 2 is a top view of the device of Figure 1.

Figure 3 is a view similar to Figure 2, without the movable plate.

FIG. 4 is a side view of the device in FIG. 2.

Figures 5a-5i illustrate different possibilities of movement of the movable plate of the device of Figures 1 to 4 relative to the fixed base.

Figure 6 is a schematic exploded perspective view of another embodiment of the device according to the invention.

Figures 7a-7i illustrate different possibilities of movement of the movable plate of the device of Figure 6 relative to the fixed base.

FIG. 8 is a schematic exploded perspective view of a variant of the embodiment shown in FIG. 6.

Figures 9a-9i illustrate different possibilities of movement of the movable plate of the device of Figure 7 relative to the fixed base.

With reference to FIGS. 1 to 4, the first illustrated embodiment of the workpiece support device 1 according to the invention, also known as the XY translation table, comprises a fixed base 2, connected to a movable plate 3, workpiece support, by an intermediate assembly 4.

Furthermore, two motorized drives 5 and 6, fixed to the base 2, are provided for the respective drive along the X axis and the Y axis, 900 from one another.

To do this, the base 2 comprises two guide rails 7 and 8, fixed at 900 from each other on the upper face 2A thereof, and defining the axes X and Y respectively, while the movable plate 3 comprises three guide rails 9, 10 and 11 fixed to the bottom 3A of said plate, the rails 10 and 11 of which are parallel to each other, and in the direction Y, and the rail 9 is perpendicular to them. As shown, said rails 7-11 have the form of bars of quadratic cross section.

Three intermediate parts 12, 13, 14, each consisting of two pads, of U-shaped cross section, with recirculation of balls assembled in pairs back to back and in two orthogonal directions, corresponding either to the direction X, or to the direction Y, connect, respectively, the guide rails 8, 9; 7, 10; and 7, 11.

Thus, the motorized drive 5, fixed on the upper face 2A of the base 2, is capable of driving the intermediate piece 13, in the direction X (guide rail 7), this drives the movable plate 3, which is decoupled from the drive in direction Y by the guide rail 9.

Similarly, the motorized drive 6, fixed on the upper face 2A of the base 2, is capable of driving the intermediate piece 12, in the direction Y (guide rail 8), this drives the movable plate 3, which is decoupled from the drive in direction X by the guide rails 10 and 11.

In Figure 6, there is shown another embodiment of the X-Y translation table according to the invention. As before, the table 1 has a fixed base 2, connected to a movable plate 3, workpiece support, by an intermediate assembly 4.

In addition, two motorized drives 5 and 6, fixed on the base 2, are provided for the respective drive along the X axis and the Y axis, 900 from one another.

To do this, the base 2 has two guide rails 15, 16, arranged 900 from each other and materializing, respectively, the axes X and Y. Similarly, the movable plate 3 has two guide rails 17, 18, arranged 900 from each other along, respectively, the axes X and
Y. Thus, the rails 15 and 17 are arranged parallel to each other in the direction X, and the rails 16 and 18 parallel to each other in the direction Y. The rails 15, 16, having a U-shaped cross section is provided on the upper face 2A of the base 2, while the rails 17, 18, likewise having a U-shaped cross section, are provided on the underside 3A of the movable plate 3.

In this case, the intermediate assembly 4 has two parts 19 and 20, substantially in the form of plates. The first 19 of these has two pads 21, 22 in the form of ribs of quadratic cross section, fixed on either side of said part respectively and at 900 from one another. The first shoe 21 is able to engage and slide in the corresponding rail 15 of the base 2, while the second shoe 22 is able to engage and slide in the corresponding rail 18 of the movable plate 3. Similarly , the second part 20 has two pads 23, 24, in the form of ribs of the same quadratic cross section, fixed on either side of said part respectively and at 900 from one another. The first shoe 23 is able to engage and slide in the corresponding rail 16 of the base 2, while the second shoe 24 is able to engage and slide in the corresponding rail 17 of the movable plate 3.

The motorized drive 5, fixed on the base 2 parallel to the rail 15, drives the intermediate piece 19 in the direction X (guidance by the rail 15 and the shoe 21), this drives the movable plate 3 which is decoupled from the drive along Y by the guide formed by the shoe 24 and the rail 17.

The motorized drive 6, fixed on the base 2 parallel to the rail 16, drives the intermediate piece 20 in the direction Y (guidance by the rail 16 and the shoe 23), this drives the movable plate 3 which is decoupled from the drive along X by the guide formed by the shoe 22 and the rail 18.

Compared to the embodiment of Figure 6, that of Figure 8 is distinguished only by the fact, on the one hand, that the base 2 has two guide rails 15, 16 parallel to one the other, that is to say being oriented at 450 with respect to one or the other of the directions X and Y and, on the other hand, that the pads 21, 22 of the first intermediate part 19 and the pads 23, 24 of the second intermediate piece 20 are arranged at 450 relative to each other, so as to be able to correspond with the guide rails 15, 16 of the base 2 and the rails 17, 18 of the mobile platform 3.

As before, the motorized drive 5, fixed on the base 2 parallel to the rail 15, drives the intermediate piece 19 along the guide formed by the rail 15 and the shoe 21, this drives the movable plate 3 which is decoupled from the motorized drive 6 by the guide formed by the shoe 24 and the rail 17.

The motorized drive 6, fixed to the base 2 parallel to the rail 16, drives the intermediate piece 20 along the guide formed by the rail 16 and the shoe 23, the latter drives the movable plate 3 which is decoupled from the motorized drive 5 by the guide formed by the shoe 22 and the rail 18. Thus, the movement of the movable plate 3 in the direction X or Y results from a combination of the movements of the motorized drives 5 and 6.

The device according to the invention has the following advantages.

The motorized drives 5 and 6 are fixed (integral with the base 2 fixed). Their lines of action concur with the axis of exploration. The moving masses are reduced, and the dynamic performance is improved.

Furthermore, the arrangement of the device according to the invention, in particular due to its symmetry, makes it possible to disembark the drives in the case of the use of the vacuum table or in a non-magnetic environment. In addition, there is the possibility of integrating measurement rules located in the axis of displacements and concurrent with the axis of exploration.

It will be noted that the advantage of integrating motorized drives, as well as the measurement rules, on axes concurrent with the exploration axis, lies in the fact that this eliminates positioning errors due to guidance faults (ABBE error).

In addition, in addition to the compactness of the assembly and the simplicity of its architecture, it is also possible to use the table for transmitted-light applications.

The parallel mounting of the motorized drives 5 and 6, in the embodiment of Figure 8, allows, in the case of constraints related to the environment of the table (vacuum tank) to require only one access area.

It will also be noted that the use, according to the invention, of motorized drives 5, 6, as arranged, implies symmetry of the loads exerted by and on said drives, which results in a simplification of the control of the system. In addition, as can be seen in FIGS. 5a-5i, 7a-7i and 9a-9i, the lift zone of the table, whatever the displacement imparted to its movable plate, is never reduced to a "point ", resulting in high rigidity of the structure.

Claims (9)

1. Device (1) for supporting the workpiece, capable of moving in first (X) and second (Y) directions, orthogonal to one another, characterized in that it comprises - a fixed base (2 ), - a movable plate (3) for supporting the part, - first (5) and second (6) motor means, intended for  moving said movable plate (3) relative to said  fixed base (2), respectively in the direction (X) and  the direction (Y), and fixed on said base (2), and - connecting means (4), disposed between said fixed base  (2) and said movable plate (3), capable of ensuring,  through said first (5) and second (6)  motor means, control of said movable plate (3),  in directions (X) and (Y), with respect to said  fixed base (2). 2. Device according to claim 1, characterized in that said connecting means (4) comprise, on the one hand, first guide rails (7, 8), fixed on said base (2), and second rails guide (9, 10, 11), fixed on said movable plate (3) and oriented, respectively, in the directions (X) and (Y), and, on the other hand, of the carriages (12, 13, 14), connecting, in pairs, said rails, each carriage connecting rails carried one by said base (2) and the other by said movable plate (3). 3. Device according to claim 2, characterized in that said guide rails (7-11) are made in the form of bars of quadratic cross section, while said carriages (12, 13, 14) are made in the form of pads U-shaped cross section assembled in pairs back to back and in two orthogonal directions. 4. Device according to claim 2 or claim 3, characterized in that two guide rails (7, 8) are fixed on the upper face (2A) of said base (2) along, respectively, the directions (X) and (Y) and three guide rails (9, 10, 11) are fixed on the underside (3A) of said movable plate (3), three said intermediate parts (12, 13, 14) connecting said rails two by two. 5. Device according to claim 2, characterized in that said connecting means (4) comprise, on the one hand, two first guide rails (15, 16) of U-shaped cross section, provided on said base (2 ), and two second guide rails (17, 18) of U-shaped cross section, provided on said movable plate (3) and, on the other hand, two carriages (19, 20) in the form of plates, each of which has two pads (21, 22; 23, 24) in the form of ribs of quadratic cross section, fixed on either side respectively of said part, each rib being able to engage and slide in the corresponding rail. 6. Device according to claim 5, characterized in that the two said first guide rails (15, 16) are provided on the upper face (2A) of said base (2) being arranged at 900 one of the another following, respectively, the direction (X) or (Y), and the two said second guide rails (17, 18) are provided on the underside (3A) of said movable plate (3) being arranged at 900 one of the other following, respectively, the direction (X) or (Y), and in that the pads (21, 22; 23, 24) of each of said intermediate parts (19, 20) are arranged at 900 one on the other to engage, respectively, in a guide rail (15, 16) provided on said base (2) and a guide rail (17, 18) provided on said movable plate (3), these latter rails being orthogonal to each other. 7. Device according to claim 5, characterized in that the two said first guide rails (15, 16) are provided on the upper face (2A) of said base (2) being arranged parallel to one another , and at an angle (a) with one or the other of the directions (X) and (Y), and in that the pads (21, 22 23, 24) of each of said intermediate parts (19, 20 ) are arranged, with respect to each other, at an angle such that they can engage in their respective guide rails (15, 16; 17, 18) of said base (2) and said movable plate (3). 8. Device according to claim 7, characterized in that said angle (a) is at least substantially equal to 450. 9. Device according to any one of claims 1 to 8, characterized in that each of said motorized drives (5, 6) is fixed to said base (2) parallel to the respective guide rail (7, 8; 15, 16) provided on said base (2).