Machine tool with three degrees of freedom intended for the sculpture with its table of order.

The invention relates to a machine tool to three degrees of freedom and its control table. The machine tool, for example, from a block of material, forming a blank, in particular a sculpture. Using photographs or planes disposed on the control table, the tool is controlled and moves to give the block of material the desired shape. The machined material is arbitrary. In the field of the sculpture, such as gypsum, clay or wood.

To work material blocks, there are machine tools more degrees of freedom. Or They are digitally controlled laser thus having many electronic components. To store the shape of the object to be reproduced, many steps are required, and photographs of the object are not sufficient. To perform these stores, the problem that the object to remain static during this operation. Therefore, it is not possible to reproduce a position of a motion model, a model or bulky. These machines allow a precision, but the price is high. For blanks, in the field of sculpting example, the highly accurate that provides these machines is not required and the price is too high to be accessible to craftsmen. On the other hand, their use is complex and for training is necessary to use such tools.

The aim of the invention is to provide a tool for machining blocks of material within the gap raised or recessed, from photographs, engraving or other planes. The tool should be of low cost and simple to use.

To this end, the tool it is of the type machine tool three degrees of freedom for the sculpture with its control table, comprising rotational drive means of a machining tool, the tool linearly displaceable relative to the workpiece in three axes, forming a mark, preferably orthogonal, and a table for controlling the displacements of the tool.

The machine tool is characterized in that the movement of the tool according to at least two axes relative to the workpiece is controlled on the control table a device mobile in translation for each axis according to which the movement of the tool is controlled, each device being provided with a mark for positioning relative to a representation of the workpiece, the control being transmitted by means of a cable guided in a sheath and a device exerting a restoring force opposite in direction to that of the force derived from a pull on the cable.

Therefore, control of the tool is mechanical. It is either manually, be powered. This allows the machine tool to have a low cost, be highly reliable and easily manipulable by an operator.

Representations of the part to be made, which can be of the etched structures, photographs, drawings sides etc, can be attached to the control table and guide the operator through the indicia associated with mobile in translation. The operator then moves the devices and controls and the tool. The devices are provided for controlling the tool according to two or three axes. If they control the movement of the tool according to two axes only, moving the tool relative to the workpiece according to the third axis can be automatically obtained by a motor.

Advantageously, the control table comprises a planar medium on which two locations are for receiving the representations of the part to be made, and three marks each consisting of a line, two lines being parallel, the third, called level line, being perpendicular to the first two, and each mark is mounted on a mobile device in translation parallel to the plane of the conveyor table and perpendicular to the mark. The intersection of these lines tracks on the representations of the part to be made of the position of the tool.

Representations attached to the control table can be for example the front views and side of the workpiece and the three markings represent the three orthogonal axes wherein the tool can move.

In a preferred embodiment, each mobile device in translation of the control table for the control of the movement of the tool relative to the workpiece comprises a wire, constituting the mark, tensioned between two tips, a connecting rod rigidly connecting the two tips, a tapped piece integral with the connecting rod, and a threaded rod engaging in the threaded part, mounted free in rotation and bearing a rotary drive means at one of its ends. The operator then acts on the drive means for moving the mobile device of the control table and thereby control the stroke of the tool. The drive means may be, for example, a crank, or a motor with a control knob.

In order to make the tool moveable in two dimensions, the tool is mounted on a mobile carriage, itself mounted mobile in translation on a table in a direction perpendicular to the previous movement and parallel to the table.

The relative movement between the tool and the workpiece, is the latter is stationary and the table supporting the carriage on which is mounted the tool is movable orthogonal to the plane defined by the table, is the machine tool includes a tray for receiving the workpiece, can move orthogonally to the plane defined by the table supporting the carriage on which the tool is mounted.

In the case where the work piece is supported by a movable tray, the latter may be rotated by all lifting means. However, the latter is advantageously guided by fixed guide pins, parallel to its direction of movement, and may also involve via a bearing, on an inclined plane, displaceable perpendicularly to the direction of movement of the tray, to control the movement of the tray.

The tool can be controlled according to three axes. The operator can easily provide control according to two axes, each of his hands controlling movement along an axis, but it becomes difficult to control the stroke of the tool along the third axis. According to the invention, the movement of the tool relative to the workpiece according to the third axis is driven by a motor and transmitted by a screw-nut device to the tool or to the workpiece, the movement causes, via a cable and a device exerting a restoring force, a mark of the control table proportional to rectilinear movement.

The biasing units acting in the opposite direction of the pulling a control cable may include counterweights, but, in a preferred embodiment, it is spring winding drums.

The representations of the part to be made to the scale can be 1:1, but it is also possible to obtain an increase or a decrease. For these various case, each cable connecting markings tool is attached, or the device carrying the marking in order to obtain displacement of the tool equal to the movement of the mark, is, according to the enlargement ratio desired, to the frame of the control table to the device carrying the marking or by passing over one or more pulleys integral with the mark and optionally on one or more pulleys mounted on the frame of the control table. To obtain special effects, it is possible to obtain a different scale of enlargement along the three axes.

In any case, the invention will be clearly understood with the aid of the description that follows, with reference to the appended schematic drawing, representing example, one embodiment of the machine tool:

Figure 1 is a schematic perspective view of the whole machine tool with its control table;

Figure 2 is a perspective view to enlarged scale of a truncated portion of the control table;

Figure 3 is a schematic of top of the control table;

Figure 4 is a schematic plan view the lower part of the table showing control the passage of a control cable for execution at the scale 1:1;

Figure 5 is a view identical to that of Figure 4 in the case of magnification;

Figure 6 is a view identical to that of Figure 4 in the event of a reduction;

Figure 7 is a schematic view the tray with the workpiece for execution at 1:1 scale;

Figure 8 is a view identical to Figure 6 for a magnification;

Figure 9 is a view identical to Figure 6 for a reduction.

Figure 1 shows the whole machine tool with its control table. A tool 1, driven by an electric motor 2 is movable in translation along two orthogonal horizontal axes. A workpiece 3 is placed on a tray 4 which is pivotally mounted to a table 5 able to move in a vertical axis.

The movement of the tool 1 is controlled by moving a control table 6 of two mobile devices in translation and that an operator can move thanks to two cranks 7, by a device.

The vertical motion of the workpiece is controlled by an electric motor 8 via a screw-nut device and an inclined plane.

The relative movements of the tool 1 and of the workpiece 3 are located on the control table 6 using three marks 9.10.11 that move at the same time that the tool 1 and that the workpiece 3. The control table 6 on the one hand, and the tool 1 and the workpiece 3 on the other hand, are connected by cables 12.

The tool 1 and its motor 2 are mounted on a carriage 13. The latter is guided by two guide rods 14 horizontal, allowing the carriage 13 to move in a direction subsequently designated by convention left/right direction. The guide rods 14 are connected to one another at each of their ends by a support 15. Each support 15 is slidably mounted on a guide rod 16, herein set horizontal and perpendicular to the guide rods 14. The guide rods 16 allow the supports 15 and also to the carriage 13 to move in a direction subsequently designated by convention front/rear direction.

The table 5, carrying the tray 4 which supports the workpiece 3, is guided by four guide pins 17 vertical. For a better rigidity of the assembly, the upper end of the four rods 17 are connected to one another by means of three control rods. The table 5 rests, via a bearing 18 on an inclined plane 19, made of a corner profile, so that the bearing 18 is guided on the inclined plane 19 by the side edges preventing the bearing 18 from leaving the inclined plane 19. At its lower end, the inclined plane 19 is connected to a beam 20 beneath which is fixed a nut 21. The other end of the inclined plane is also attached to a joist assembly 20/nut 21, but via a vertical post 22, so that the two nuts 21 are aligned in a horizontal plane and parallel to the lateral edges of the corner. A long pitch trapezoidal threaded rod 23 is engaged in the two nuts 21. The two beams 20 are guided on two guide pins 24, parallel to the threaded rod 23. The guide rods 24 are connected to one another at each of their ends by means of a connecting rod 25. The one of the cage bars 25 also carries the electric motor 8 which drives the threaded rod 23 in rotation. One end of the threaded rod 23 is then connected to the motor 8, the other is free of any thread, and is mounted on the other bar 25. Therefore, when the engine 8 is running, the threaded rod rotates and via the nuts 21, the inclined plane 19 moves along the threaded rod, causing the raising or lowering of the table 5 carrying the workpiece 3. The motor 8 is controlled by a foot control 48.

The control table 6 comprises, mounted on a frame, a planar support 26 on which two locations are for receiving representations 27 of the part to be made (Figure 3). Representations 27 can be photographs, or etches, or even the drawings sides, andc. 9.10.11 Three marks constituted by lines move on the planar support 26. 10.11 Two marks are parallel, the third 9 is perpendicular to the other two and is called level line. The intersecting points of the marks permits the position of the tool in space, by locating a same point on the two representations 27.

10.11 The two marks are a line embodied by a wire. The being stretched between two tips 28, interconnected by two link bars 29, parallel to the wire, which carry, substantially in its middle, a tapped piece 30, integral with the connecting rods 29. The female thread of the workpiece 30 is perpendicular to connecting bar 29 and it is engaged with a threaded rod 31, provided at one end of a crank 7, which is used to rotate the support about its longitudinal axis. The threaded rod 31 is mounted on bearings (not shown in the drawing).

The marker 9 said level is also a line embodied by a wire. However, it is attached to a rule 33 guided by a guide rod 34, parallel to the marks 10 and 11. The marker 9 is orthogonal to the two other markers. The guide rod 34 is attached to the control table 6 by two supports 35.

The connection between the tool 1 and the table 5 on the one hand and the reference marks of the control table 6 is carried out by means of the cables 12. A cable 12 is attached to the carriage 13 carrying the tool 1. The cable 12 is guided in a sleeve 36, bearing on a tip integral with the support 15 guide rods 14 of the carriage, to the control table 6. The frame of the control table has a hole for passing the cable 12 and on the edge of which the sheath 13 is supported.

27 If the representations are to the scale 1:1 (Figure 4), the end of the cable 12 is attached to a point integral with the mark 10. Therefore, when the marker 10 moves from a unit length, the carriage 13 also moves a unit length.

Si to the size of the object to perform the scale representations are 27 Guests (Figure 5), the cable 12 passes through the hole of the frame of the control table, passes over one or more pulleys 37 integral with the mark 10 to lengthen the travel of the cable in relation to the distance travelled by the marker and optionally on one or more pulleys 38 interdependent with the frame of the conveyor table and its end is then either connected to the frame of the control table, or a point integral with the mark 10.

Si to the size of the object to perform the scale representations 27 are enlarged (Figure 6), the end of the cable 12 is set in the vicinity of one of the pulleys 37 integral with the mark and the end of the sheath 13 is supported in the vicinity of another pulley 37 integral with the mark. These two pulleys are guided on two rods at V, so that, when the marker moves, the pulleys 37 move together or apart from each other along the direction of movement of the mark. According to the angle formed by the branches of the V, the reduction ratio is more or less large.

The principle is exactly the same for the cable 12 connected to the mark 11 which is for example attached to one of the supports 15 guide rods 14 guiding the carriage 13.

For the cable connected to the mark 9, the principle is exactly the same, but the system of pulleys is arranged on the tool side (Figures 7 to 9).

The cables connected to the 12 marks 10 and 11 controls the movement of the tool 1, while the third cable 12, mark 9 connected to the said level controlling the same. The cables cannot move the tool 1 or the mark 9 that if traction is exerted on them. It can control the movement in only one direction. To control in the other direction, it is necessary to have a restoring force which acts in this direction. To apply this spring force, is simply fastened a cable 39 to a point of the carriage 13 and of the support 15 located opposite the point where the cable 12 is attached, pass the cable over a pulley 39 40 connected to a point fixed relative to the rod motion guide concerned and to hang a counterweight shown in the drawing by an arrow. The counterweight and the pulley 40 may be replaced by a spring loaded drum reel (not shown).

The operation of the machine tool is as follows.

The workpiece 3 is placed on tray 4. The tray is secured against rotation. The tool 1 is positioned with respect to this part 3. It is then possible to position the two representations 27 of the part to be made, which are both to the same scale, on the support 26 of the control table 6. Indeed, the position of the tool relative to the workpiece 1 3 is known. On the support 26, the position of the tool is indicated by the position and the intersection of the marks 9.10 and 11, it is only necessary to place the representations 27 relative to the axes of the marks and to the position of the tool 1. The yarn called level 9 is common to the two representations 27.

Representations 27 can be, for example, a front view and left view of the part to be obtained. To work the part 3, the motors 2.8 which drives the tool 1 and the table 5 are turned on. The table 5 moves vertically, and this movement causes, via a cable 12, the mark 9 in translation along its guide rod 34. Using the cranks 7, the marks 10 and 11 are moved, so that the intersections of the marks 9 and 10, and 9 and 11 on the representations 27 follow the desired contour common point by common point. Movement of the control marks 10 and 11, as set forth above, the movement of the tool 1, which machines the workpiece 3 then, by successive approximations in the material.

To facilitate the operation, indicia can be traced on the embodiment. For example of a grid or mesh which aid in navigating then the operator to follow a same contour on the representations 27.

When the machining is finished, it may be desirable to machine another side of the workpiece. The same operations that previously are to be recommenced. The representations are then used for example a right view and front view. The part 3, partially machined, is rotated by a half-turn. The tray 4 being pivotable, a matter of rotating the tray 4 and lock it against rotation and reverse the sheath of the cable. The part can then be machined.

Since it is a matter of course, the invention is not limited to the single embodiment described above example; on the contrary it embraces all variants.

Therefore, for example, instead of powering the rise and fall of the table on which the workpiece exists, it is possible to motorize the apparatus which supports the corresponding mark to move automatically on the table of the control table and drives, as do the further marks and the associated devices, the table in translation.

The cranks can also be replaced by motors actuated by means of a control.

The vertical motion of the workpiece is controlled by a motor, a screw-nut system and an inclined plane. Any other lift mode may be suitable, as for example cylinder.

Also, the workpiece can very well remain stationary, and in this case, then that is the tool that moves vertically.

Evokes The description is not that a job of the scale 1:1 from the planes, or magnification. A reduction is also possible. Only pass wires on the tool over pulleys, and they pass over pulleys side control table.

Furthermore, the directions of movement of the tool 1 may not be orthogonal. They, for example, may be an angle to each other of 45 °, which is then the angle of the images.