Discharging plate-shaped workpiece parts that have been cut free

Abstract

A machine for separative machining of a plate-shaped workpiece by a processing beam. The machine has a first movement unit for moving the workpiece in a first direction, a second movement unit for moving a processing head in a second direction, two workpiece bearing supports for bearing the workpiece, and a parts chute. The two workpiece bearing supports are separated from each other by a gap that extends along the second direction. The parts chute is movable between a first chute position and a second chute position so as to move a cut-free workpiece part that has dropped into the gap, laterally away from the gap. The machine includes a receiving unit movable in the second direction, to receive the cut-free workpiece part at a transfer position and transport the workpiece part to one or more discharging positions of the machine along the second direction.

Claims

1. A machine for separative machining of a plate-shaped workpiece by means of a processing beam, the machine comprising: a first movement drive operable to move the workpiece in a first direction; a second movement drive operable to move a processing head in a second direction, the processing beam being directed towards the workpiece by the processing head; two workpiece bearing supports arranged to bear the workpiece, the two workpiece bearing supports being separated from each other by a gap that extends along the second direction such that a workpiece part that is cut free from the workpiece drops into the gap; a parts chute movable between a first chute position and a second chute position with respect to the gap, wherein in the second chute position a chute face of the parts chute is arranged in the gap so as to move the workpiece part that is cut free from the workpiece and dropped into the gap, laterally away from the gap; and a collection carriage movable in the second direction to receive the workpiece part at a transfer position, the collection carriage being configured to transport the workpiece part received at the transfer position to one or more discharging positions of the machine along the second direction, wherein the collection carriage has at least one discharging barrier movable between a first position to support the workpiece part and a second position to discharge the workpiece part.

2. The machine of claim 1, wherein the discharging barrier in the first position forms at least a subarea of a bottom side of the collection carriage, and in the second position (S2) uncovers an opening at least in the subarea of the bottom side.

3. The machine of claim 1, further comprising at least one support slide that is displaceable in the second direction in the gap and has a bearing face for supporting workpiece parts cut during separative machining, wherein the support slide or the bearing face is lowerable.

4. The machine as claimed in claim 1, further comprising a controller configured to control movement of the collection carriage between the transfer position and the one or more discharging positions of the machine in the second direction.

5. The machine of claim 4, wherein the controller is configured to arrange two support slides that are displaceable within the gap in the second direction such that in a first arrangement the two support slides are arranged adjacent to each other in order to support the workpiece part when the workpiece part is cut free, and in a second arrangement the two support slides are arranged such that a spacing between the two support slides is enlarged in the second direction in order to drop the workpiece part into the gap.

6. The machine of claim 5, wherein the controller is configured to determine the transfer position of the collection carriage based on a center of gravity position of the workpiece part along the second direction when the workpiece part is cut free.

7. The machine of claim 6, wherein each of the two support slides has a respective bearing face that bears the workpiece, and wherein the controller is configured to determine the transfer position of the collection carriage in the second direction in relation to a central position between mutually facing edges of the bearing faces of the two support slides when the two support slides are arranged in the first arrangement.

8. The machine of claim 7, wherein the controller is configured to determine the transfer position based on a difference between the center of gravity position of the workpiece part and the central position.

9. The machine of claim 1, wherein the two workpiece bearing supports bear the workpiece on a bearing plane, the machine further comprising: a suction box arranged in the gap below the bearing plane.

10. The machine of claim 9, wherein the parts chute in the first chute position forms a portion of a side wall of the suction box.

11. The machine of claim 1, wherein the parts chute is pivotable and/or displaceable from the first chute position to the second chute position.

12. The machine of claim 1, wherein the parts chute extends along an entire length of the gap, the length of the gap extending along the second direction.

13. The machine of claim 1, wherein the parts chute has at least one damping layer to damp an impact of workpiece parts that drop into the gap and impact the chute face.

14. A method of discharging a workpiece part from a machine in connection with separative machining of a plate-shaped workpiece by a processing beam, the method comprising: moving a parts chute of the machine from a first chute position to a second chute position, wherein the workpiece bears on two workpiece bearing supports that are separated by a gap, such that a workpiece part cut free from the workpiece drops into the gap, and wherein the parts chute moves from the first chute position to the second chute position with respect to the gap, wherein the parts chute in the first position does not protrude into a movement range of the processing beam in the gap, and wherein in the second chute position, a chute face of the parts chute is arranged in the gap so as to move the workpiece part that is cut free from the workpiece and dropped into the gap, laterally away from the gap; receiving the workpiece part by a collection carriage that is located at a transfer position next to the gap; displacing the collection carriage along the gap for transporting the workpiece part to a discharging position along the gap; and discharging the workpiece part from the collection carriage at the discharging position, wherein the workpiece is movable in a first direction by a first movement drive, wherein the processing beam is directable towards the workpiece by a processing head that is movable in a second direction by a second movement drive, and wherein the gap extends along the second direction, wherein the collection carriage is movable in the second direction to receive the workpiece part at a transfer position, and wherein the collection carriage has at least one discharging barrier movable between a first position to support the workpiece part and a second position to discharge the workpiece part.

15. The method of claim 14, wherein the parts chute does not protrude into the gap in the first position.

16. The method of claim 14, further comprising: arranging two support slides that are displaceable within the gap so as to be adjacent to each other in the gap to support the workpiece part when the workpiece part is cut free; and enlarging a spacing between the two support slides to allow the cut-free workpiece part to drop into the gap.

17. The method as claimed in claim 14, wherein the transfer position of the collection carriage is determined based on a center of gravity position of the workpiece part along the gap when the workpiece part is cut free.

18. The method of claim 17, wherein the transfer position of the collection carriage is offset from the center of gravity position.

19. The method of claim 17, further comprising arranging two support slides that are displaceable within the gap so as to be adjacent to each other in the gap to support the workpiece part when the workpiece part is cut free, wherein each of the two support slides has a respective bearing face that bears the workpiece, and wherein the transfer position is determined based on a difference between the center of gravity position of the workpiece part and a central position between mutually facing edges of the bearing faces of the two support slides that are arranged adjacent to each other when the workpiece part is cut free.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows a schematic illustration of an exemplary embodiment of a machine for separative machining of a plate-shaped workpiece in the form of a laser cutting machine that has a gap that is formed between two workpiece bearing faces.

(2) FIGS. 2A and 2B show a detailed illustration of the machine of FIG. 1, having a parts chute that extends along the gap. The parts chute as shown in FIG. 2A is arranged in a position outside the gap, that is to say does not protrude into said gap, and as shown in FIG. 2B is arranged in a position that is pivoted into the gap. FIGS. 2A and 2B also show an illustration of a receiving unit in the form of a collection carriage that is displaceable parallel to the gap.

(3) FIGS. 3A-3C show illustrations of a collection carriage in the movement from a transfer position to one of a plurality of discharge positions laterally along the gap, in each case one collection container being disposed at said discharge positions.

(4) FIGS. 4A and 4B show an illustration of the collection carriage in a transfer position having a lateral offset in relation to a central position between two support slides that are arranged so as to be adjacent to each other in the gap, as well as the spread of the positions of a workpiece part during the transfer into the collection carriage.

(5) FIGS. 5A and 5B show a schematic view of the cross section of the gap, having a suction box that is disposed in the gap, as well as having the parts chute of FIGS. 2A and 2B in the first position, or in the second position, respectively.

(6) FIGS. 6A and 6B show an illustration analogous to that of FIGS. 5A and 5B, in which the parts chute is displaced in a linear manner in the movement from the first to the second position;

(7) FIGS. 7A and 7B show an illustration analogous to that of FIGS. 5A and 5B, in which the suction box is displaced downward in the movement of the parts chute from the first to the second position;

(8) FIGS. 8A and 8B show an illustration analogous to that of FIGS. 5A and 5B, in which the suction box is also laterally displaced in the movement of the parts chute from the first to the second position; and

(9) FIGS. 9A and 9B shows an illustration analogous to that of FIGS. 5A and 5B, in which the parts chute is extended in the manner of a telescope in the movement of the parts chute from the first position to the second position.

(10) Identical reference signs are used for the same components, or for components of equivalent function, respectively, in the following description of the drawings.

DETAILED DESCRIPTION

(11) FIG. 1 shows an exemplary construction of a machine 1 for separative machining, more specifically for laser cutting, of a plate-shaped workpiece 2 (illustrated in dashed lines) by means of a processing beam in the form of a laser beam 3 which is produced by a laser source not specified here. In order for the workpiece 2 to be cut, another type of thermal processing beam, for example a plasma jet or a water jet, can also be used instead of the laser beam 3. The workpiece 2 when being processed bears on two stationary workpiece bearing faces 4, 5 (or workpiece bearing supports) which in the example shown form the upper sides of two workpiece tables and define a workpiece bearing plane E (X-Y plane of a XYZ coordinate system) for bearing the workpiece 2. The workpiece bearing faces 4, 5 can be formed by table faces or by pin-shaped bearing elements (pins), bearing belts, brushes, rollers, balls, air cushions, or the like.

(12) The workpiece 2 by means of a conventional motion and holding unit (or movement drive) 7 which has a drive and clamping installations in the form of clamping jaws for fixedly holding the workpiece 2 can be displaced in a controlled manner in a first direction X (hereunder: X-direction) on the workpiece bearing faces 4, 5 and be moved to a predefined workpiece position X.sub.W. In order for the movement of the workpiece 2 in the X-direction to be facilitated, brushes, balls, or slide rollers which represent the actual workpiece bearing faces 4, 5 can be attached to the workpiece tables shown in FIG. 1. Alternatively, in order for the workpiece 2 to be moved in the X-direction, or in order for said movement of the workpiece 2 to be supported in the X-direction, it is possible for example for the workpiece bearing faces 4, 5 per se to be designed as a motion unit, for example in the form of a (revolving) conveyor belt as is described in DE 10 2011 051 170 A1 of the applicant, or in the form of a workpiece bearing as is described in JP 06170469.

(13) A gap 6 that is laterally delimited by the stationary workpiece bearing faces 4, 5 is formed between the two stationary workpiece bearing faces 4, 5. The gap 6 extends in a second direction (hereunder: Y-direction) along the entire width of the two workpiece bearing faces 4, 5. A laser cutting head 9 which directs and focuses the laser beam 3 onto the workpiece 2 is displaceable in a controlled manner in the Y-direction by means of a driven slide 11 which serves as a movement unit (or movement drive) and which is guided on a stationary gantry 10. The laser cutting head 9 in the example shown is additionally also displaceable in the X-direction and, with the aid of an additional movement unit 12, for example in the form of a linear drive, that is attached to the slide 11 can also be displaced in a controlled manner in the X-direction.

(14) The laser cutting head 9 with the aid of the mutually complementary movement units 11, 12 can be positioned both in the X-direction as well as in the Y-direction at a desired cutting head position XS, YS within the gap 6.

(15) Two support slides 14a, 14b are disposed in the gap 6 shown in FIG. 1 in order to additionally support the workpiece 2 and in order to support workpiece parts that are cut during separative machining. The two support slides 14a, 14b extend in each case across the entire width b of the gap 6 and are displaceable in a controlled and mutually independent manner in the Y-direction in the gap 6. The controlled movement of the support slides 14a, 14b along the lateral edges of the stationary workpiece bearing faces 4, 5 can be performed with the aid of spindle drives, for example, wherein the spindle nut is attached to the respective support slide 14a, 14b and the spindle as well as the drive motor are attached to one of the two stationary workpiece bearings 4, 5. It is understood that the controlled movement of the support slides 14a, 14b can also be implemented in another way.

(16) The support slides 14a, 14b can in each case be moved along the second Y-direction to a desired position Y.sub.UA, Y.sub.UB in the gap 6, so as to there support the workpiece 2, more specifically to support workpiece parts that are to be cut-free from the workpiece 2, or have been cut when machining, by means of a bearing face 15a, 15b. The bearing face 15a, 15b is installed at the respective support slide 14a, 14b, as can be better seen in FIGS. 2A and 2B. In the case shown, the bearing face 15a, 15b of a respective support slide 14a, 14b terminates in the Z-direction so as to be flush with the workpiece bearing faces 4, 5, that is to say that the bearing faces 15a, 15b of the support slides 14a, 14b are located in the bearing plane E for the workpiece 2. The bearing faces 15a, 15b can have a first subarea made of a heat-resistant material as well as a second subarea that adjoins the first subarea and can be configured as a brush bearing, for example.

(17) The movement of the support slides 14a, 14b can be performed in a synchronous manner, that is to say that the spacing between the position Y.sub.UA of the first support slide 14a and the position Y.sub.UB of the second support slide 14b in the second (Y) direction can be constant during the movement. The movement of the first support slide 14a can also be performed independently of the movement of the second support slide 14b, that is to say that the spacing between the position Y.sub.UA of the first support slide 14a and the position Y.sub.UB of the second support slide 14b can vary during the movement in the Y-direction, as will be described in more detail below.

(18) In the example shown in FIG. 2, in each case one support element 13a, 13b and one covering element 24a, 24b (of which only a first covering element 24a is shown in FIGS. 2A and 2B) for covering the gap 6 between the two workpiece bearing faces 4, 5 are attached to the support slides 14a, 14b, more precisely to the lateral edges of the bearing faces 15a, 15b, said lateral edges running in the X-direction and facing away from one another. The support elements 13a, 13b and the covering elements 24a, 24b extend across the entire width b of the gap 6, and are conjointly moved with the movement of the support slides 14a, 14b in the Y-direction. The covering elements 24a, 24b in the example shown are configured in the manner of roller blinds, but can also be configured in another manner, for example so as to be telescopic, imbricated, as a rolled-up belt, etc. The upper side of the support elements 13a, 13b and the covering elements 24a, 24b are level with the bearing faces 15a, 15b of the support slides 14a, 14b, or with the workpiece bearing faces 4, 5. The support elements 13a, 13b and the covering elements 24a, 24b serve for bearing subareas of the (residual) workpiece 2 that protrude into the gap 6 and are not rigid in flexural terms and without such a bearing could potentially collide with the support slides 14a, 14b.

(19) For controlling the cutting machining, the machine 1 has a control unit 16 (or controller) which is illustrated in FIG. 1 and which serves for coordinating the movements of the workpiece 2, of the laser cutting head 9, as well as of the support slides 14a, 14b so as to set a desired workpiece position X.sub.W, a desired cutting head position X.sub.S, Y.sub.S, and a desired position Y.sub.UA, Y.sub.UB of the support slides 14a, 14b, so as to enable the cutting of a predefined cutting contour, and for supporting the workpiece 2 close to the gap 6 if required. The control unit 16 in the example shown also serves for moving a parts chute 17 shown in FIGS. 2A and 2B in a controlled manner as well as a receiving unit 18 in the form of a collection carriage for receiving workpiece parts from the parts chute 17.

(20) The parts chute 17 is shown in FIG. 2A in a first vertical position S1 (first chute position) in which the parts chute 17 does not protrude into the gap 6, such that scrap parts, cutting waste, and cinder that is created in the cutting process drop into a suction box 20 that is disposed below the workpiece bearing plane E in the gap 6. A displaceable collection tub 8 in which the cutting waste and scrap parts accumulate and which for emptying can be pulled out of the machine 1 is disposed in the suction box 20. The suction box 20 is connected to a blower so as to suction the cinder, gases, and smoke from a suction region that is formed within the suction box 20. As can likewise be seen in FIGS. 2A and 2B the suction box 20 closes the suction region and can be largely tight in relation to the environment, that is to say that the suction box 20 has only one opening upwards toward the workpiece bearing plane E, said opening being largely covered by the covering elements 24a, 24b as well as by the support slides 14a, 14b. As can be seen in FIGS. 2A and 2B, the suction box 20 has a first vertically running side wall 20a as well as a second vertically running side wall 20b, the suction region located therebetween. The parts chute 17 in the first position shown in FIG. 2A, more specifically the rear side 17b of the parts chute 17 that faces away from the chute face 17a, forms a portion of the first vertical sidewall 20a of the suction box 20, while the second vertical side wall 20b of the suction box 20 is configured so as to be integral. The walls 20a, 20b and the base of the suction box 20 can be interconnected or can be composed of separate components which are sealed in relation to one another.

(21) The parts chute 17 in the second position S2 thereof (second chute position) shown in FIG. 2B is pivoted into the gap 6 such that workpiece parts that are formed in the cutting of the workpiece 2 and drop into the gap 6 or into the suction region impact the parts chute 17, more specifically the chute face 17a of the latter. The chute face 17a of the parts chute 17 in the second position S2 is disposed at an angle in relation to the workpiece bearing plane E such that workpiece parts that impact the chute face 17a under the effect of gravity slide along the chute face 17a, can be removed laterally from the gap 6, and can be received by the collection carriage 18 that is arranged laterally next to the gap 6.

(22) In the machine 1, an actuator in the form of a pneumatic cylinder 21 is provided for pivoting the parts chute 17 from the first position S1 to the second position S2 and vice versa, said pneumatic cylinder 21 being displaceable between a first terminal position in which the parts chute 17 assumes the first position S1, and a second terminal position in which the parts chute 17 assumes the second position S2. It is understood that the drive for the movement of the parts chute 17 can also be implemented in another manner.

(23) The movement of the parts chute 17 from the first position S1 to the second position S2 is typically performed only at the point in time at which the completion of the cut is performed, that is to say as soon as the workpiece part has been cut free from the (residual) workpiece, and the laser beam 3, more specifically the laser source for generating the laser beam 3, has been switched off. The parts chute 17 can be pivoted from the first position S1 to the second position S2, wherein a lowering movement of the two support slides 14a, 14b below the workpiece bearing plane E is performed in parallel therewith. This lowering movement of the support slides 14a, 14b enables a workpiece part that has been cut free from the (residual) workpiece 2 to be ejected. The workpiece part 2a drops onto the parts chute 17 due to a subsequent opposing outward movement of the support slides 14a, 14b. Wiper elements (for example brushes which are not visible in the images) can be disposed on the lower side of the support elements 13a, 13b, said wiper elements in a movement of the support slides 14a, 14b below the support elements 13a, 13b pushing the workpiece part 2a from the support slides 14a, 14b.

(24) In some examples, the pivoting of the parts chute 17 is typically performed only once the laser beam 3 has been switched off, so as to minimize any contamination of the parts chute 17, or so as to prevent the egress of cutting waste, gas, or smoke from the suction box 20, respectively, when the parts chute 17 is moved from the first position S1 to the second position S2 and an opening in the suction box 20 is uncovered. Depending on the type, the size, and the arrangement of the workpiece part 2a to be discharged, the movement of the parts chute 17 to the second position S2 can commence prior to or during the last separation cut, so as to reduce the time required for discharging the workpiece parts 2a.

(25) In order for the earliest possible point in time at which the parts chute 17 can be pivoted from the second position S2 back to the first position S1 to be identified, a sensor unit (not illustrated) that identifies at which point in time a workpiece part departs from the parts chute 17 can be used. For this purpose, the sensor unit can for example have one or a plurality of light barriers, or a light grid so as to detect the egress of the workpiece part from the suction region that is formed in the suction box 20. When said egress is identified, the control unit 16 can trigger the pivoting of the parts chute 17 from the second position S2 to the first position S1. A sensor unit for detecting the workpiece part being caught can optionally also be attached to the collection carriage 18. Alternatively or additionally, the fall time of the workpiece part, that is to say the duration required by the workpiece in order to make its way from the workpiece bearing plane E to the parts chute 17 can be determined. Optionally the duration required by the workpiece for sliding along the chute face 17a of the parts chute 17 and for departing from the latter in the direction toward the collection carriage 18, can be determined. For this purpose, the control unit 16 which serves for controlling the movement of the parts chute 17 can optionally access a database in which respective experimental characteristic data for different workpiece parts, for example for different workpiece geometries, workpiece materials, and workpiece thicknesses, is stored. The pivoting of the parts chute 17 from the second position S2 to the first position S1 can be performed as early as possible so as to be able to resume the cutting process as soon as possible and to optimize the productivity of the machine 1 in this manner. In order for accelerating the conveying of the workpiece part from the parts chute 17, the commencement of the movement of the parts chute 17 from the second position S2 to the first position S1 can optionally already be performed at a point in time at which the workpiece part impacts the parts chute, or the chute face 17a. Since the parts chute 17 in the movement from the second position S2 to the first position S1 is gets into a steeper position, the conveying of the workpiece part can be facilitated by such movement.

(26) As can be seen in FIGS. 2A and 2B the parts chute 17 has an elongate profile having a substantially wedge-shaped cross section. The parts chute 17 at the wide end of the wedge-shaped cross section on both sides has shaft studs that are rotatably mounted on the main body of the machine 1. The chute face 17a of the parts chute 17 in the example shown is formed by a structured stainless steel metal sheet, so as to facilitate the sliding of workpiece parts, to avoid damage to workpiece parts, and to reduce the wear on the parts chute 17. As is indicated in FIG. 2A, a damping layer 17c which forms an intermediate tier and which is intended to reduce the noise generated by dropping workpiece parts is attached under the structured metal sheet that forms the chute face 17a. The impact of the dropping workpiece parts can also be damped by a damping layer 17c of this type, and damage to the workpiece parts can thus be avoided. Copper sheets are fitted to the rear side 17b of the parts chute 17, to prevent cinder from the adhering to the parts chute 17 when the latter is positioned in the first position S1 in which said parts chute 17 closes the suction box 20. The suction box 20 can be sealed by seals against which the parts chute 17 pivots in the movement to the first position S1. The seals can be provided on all sides about the opening of the suction region of the suction box 20 that is closed by the parts chute 17. As can likewise be seen in FIGS. 2A and 2B, in the example shown in FIGS. 3A-3C, the parts chute 17 extends across the entire length L of the gap 6 between the two workpiece bearing faces 4, 5. In this way, it is achieved that the parts chute 17 can receive cut-free workpiece parts at any arbitrary position along the gap 6 and can convey said workpiece parts laterally next to the gap 6.

(27) For the controlled movement of the collection carriage 18 in the second direction Y, the machine 1 has an actuator in the form of a linear drive 22 which enables the collection carriage 18 to be displaced laterally next to the gap along a guide rail 23 (sorting axis) that extends in the Y direction. The collection carriage 18 at a respective transfer position Y.sub.UP can in this way receive or catch workpiece parts 2a that have been discharged from the gap 6 at different positions (see FIGS. 3A-3C), and move said workpiece parts 2a to a desired discharging position Y.sub.A1, Y.sub.A2, . . . along the gap 6, where (in each case) one collection container 25 in the form of a parts box is disposed. The collection carriage 18 therefore enables for example the workpiece parts 2a discharged from the parts chute 17 to be sorted into different collection containers 25, depending on the size, geometry, etc. of said workpiece parts 2a. As can be seen in FIGS. 2A and 2B the collection containers 25 are arranged in the Y-direction in one row on a box truck 26, the latter enabling the collection containers 25 or the boxes to be retrieved from the machine 1 in that the box truck 26 is moved in the Y-direction so as to empty said machine 1. Accordingly, the collection containers 25 can be fed to the machine 1 by way of a movement of the box truck 26, in order for said collection containers 25 to be positioned laterally next to the gap 6.

(28) FIGS. 3A-3C in a highly schematic manner show the displacement movement of the collection carriage 18 from the transfer position Y.sub.UP at which a workpiece part 2a that has been cut free from the workpiece 2 is received by the collection carriage 18, to a second discharge position Y.sub.A2 of a total of seven discharge positions Y.sub.A1, Y.sub.A2, . . . along the gap 6. A second collection container 25 of the row of collection containers 25 is disposed at the second discharge position Y.sub.A2. The collection carriage 18 is typically positioned at the transfer position Y.sub.UP during the cutting of the workpiece part 2a by means of the laser beam 3, said transfer position Y.sub.UP depending on the cutting-free position of the cut-free workpiece part 2a in the second (Y) direction along the gap 6 and thus typically depending on the position of the support slides 14a, 14b.

(29) As has been described above, the cutting of the workpiece 2 can be resumed when the cut-free workpiece part 2a has been caught by the collection carriage 18 or optionally at an earlier point in time. Therefore, the sorting of workpiece parts 2a into different collection containers 25 or boxes with the aid of the collection carriage 18 can be performed in parallel with the main time, that is to say simultaneously with the cutting of the workpiece 2 by the laser beam 3. As is shown in FIGS. 3A-3C, the collection carriage 18 having the received workpiece part 2a first travels for this purpose above a desired collection container 25, that is to say to one of a plurality of discharging positions Y.sub.A1, Y.sub.A2, . . . along the gap 6, and ejects the received workpiece part 2a into the respective collection container 25 so that the workpiece part 2a is allowed to drop into the collection container 25.

(30) In order to allow the workpiece part 2a to drop into the collection container 25, the collection carriage 18 at the bottom side 27 thereof has two discharging units (or discharge barriers) which are configured in the form of laterally displaceable sliders 28a, 28b and which are displaceable in the horizontal direction between a respective first position S1 and a respective second position S2. The sliders 28a, 28b in the first position S1 thereof cover a respective subarea of the bottom side 27, and in the second position S2 uncover an opening 29 in that subarea of the bottom side 27 that is covered in the first position S1. In the example shown in FIGS. 3A-3C, the two sliders 28a, 28b are displaced in a synchronous and opposing manner, that is to say in the negative and the positive Y-direction, respectively, from the first position S1 to the second positon S2, on account of which the spacing between the sliders 28a, 28b is enlarged and an opening 29 that extends substantially across the entire bottom side 27 is formed in the bottom side 27, as can be seen in FIG. 3C.

(31) The control unit 16 has a respective drive for the controlled movement of the sliders 28a, 28b from the first position S1 to the second position S2 (and vice versa). It is understood that the discharging unit(s) can also be configured and/or moved in a manner other than shown here. The discharging units(s) can be configured, for example, as downwardly pivotable flaps, in order for the cut-free workpiece part 2a to be discharged. A single slider or a single flap can optionally also be used as a discharging unit instead of two sliders 28a, 28b.

(32) In the case of the examples shown in FIGS. 2A and 2B and in FIGS. 3A, 3B and 3C the collection carriage 18 can be moved only in the Y-direction. However, it is understood that the collection carriage 18 additionally can optionally also be displaceable in the X-direction. In this case, for example, each discharging position Y.sub.A1, Y.sub.A2, . . . in the Y-direction can be assigned two or more discharging positions in the X-direction, so as to deposit cut-free workpieces 2a in collection containers 25 that are disposed beside one another in two or more rows in the X-direction. Sorting of workpiece parts 2a into a greater number of collection containers 25 can be performed in this way.

(33) As can likewise be seen in FIGS. 3A-3C the collection carriage 18 has lateral inclines that act in the manner of a funnel so as to channel the cut-free workpiece 2a to the lowest point of the collection carriage 18, that is to say toward the bottom side 27 where the two sliders 28a, 28b are disposed. The discharging of the workpiece part 2a from the machine 1 on account of the enlargement of the spacing between the sliders 28a, 28b is performed in a manner analogous to that of allowing the workpiece part 2a after cutting free to drop into the gap 6, this being described in more detail hereunder by means of FIGS. 4A and 4B.

(34) FIG. 4A shows (from above) the two support slides 14a, 14b that for cutting free a workpiece part 2a, which in the example shown is triangular from the (residual) workpiece 2 (not shown in FIGS. 4A and 4B), are arranged mutually adjacent in the gap 6. In the adjacent arrangement, the two support slides 14a, 14b are typically arranged at a spacing A which is approximately 5 mm. A narrow cutting region in which the workpiece part 2a is severed from the (residual) workpiece 2 with the aid of the laser beam 3 at a cutting-free position FP is thus formed between the two support slides 14a, 14b in this position. After the laser beam 3 has been switched off, the two support slides 14a, 14b in an opposing synchronous movement in the negative and in the positive Y-direction, respectively, are moved from the adjacent position shown in FIG. 4A, on account of which the spacing A between the two support slides 14a, 14b is enlarged, until the cut-free workpiece part 2a drops into the gap 6 between the two support slides 14a, 14b and impacts the parts chute 17 that has been pivoted into said gap 6.

(35) As is indicated in FIG. 4A, the cut-free workpiece part 2a does not necessarily depart from the parts chute 17 at the cutting-free position FP, or close to a central position Y.sub.M between the mutually facing edges 30a, 30b of the two support slides 14a, 14b that are in the adjacent position shown in FIG. 4A. Rather, the position at which the cut-free workpiece part 2a departs from the parts chute 17 can vary in the Y-direction, that is to say that this position has a spread, which typically is not predictable in a deterministic manner. In order for the cut-free workpiece parts 2a to be able to be securely caught, the collection carriage 18 therefore has a length L.sub.W in the Y-direction, which can for example be approximately 50 cm. The length L.sub.W of the collection carriage 18 in the Y-direction should not be chosen so as to be excessive, in order to prevent the collection carriage 18 from having an excessive weight that reduces the dynamic behavior of the movement of the collection carriage 18 when transporting workpiece parts 2a.

(36) It is understood that the collection carriage 18 is ideally to be positioned at a transfer position Y.sub.UP in the Y-direction at which the probability of the cut-free workpiece part 2a departing from the parts chute 17 is the highest. If the cut-free workpiece part 2a bears in the Y-direction on the bearing faces 15a, 15b of the support slides 14a, 14b so as to be centric or substantially centric, the transfer position Y.sub.UP can coincide with the central position Y.sub.M of the support slides 14a, 14b when cutting free. However, should the cut-free workpiece part 2a bear completely or almost completely on one of the two bearing faces 15a, 15b, it is favorable for a lateral offset to be provided between the central position Y.sub.M and the transfer position Y.sub.UP, said lateral offset taking into account the spacing |Y.sub.WS-Y.sub.M| between the center of gravity position Y.sub.WS of the workpiece part 2a in the Y-direction and the central position Y.sub.M of the two support slides 14a, 14b. The transfer position Y.sub.UP, that is to say the central position of the collection carriage 18 in the Y-direction, can be shifted in relation to the central position Y.sub.M in the Y-direction by double said spacing |Y.sub.M-Y.sub.WS|, for example.

(37) If the workpiece part 2a bears mainly on the bearing face 15b of the second support slide 14b, for example, the transfer position Y.sub.UP is thus laterally offset in the positive Y-direction. By the lateral offset it is taken into consideration that the workpiece part 2a that bears on the bearing face 15b of the second support slide 14b by virtue of friction forces is entrained in the movement of the second support slide 14b in the positive Y-direction, such that said workpiece part 2a is imparted a (substantially deterministic) lateral offset in the Y-direction. It is understood that a lateral offset of the transfer position Y.sub.UP in the negative Y-direction can be determined in an analogous manner, provided that the cut-free workpiece part 2a largely bears on the bearing face 15a of the first support slide 14a. It is understood that, alternatively or in addition to the center of gravity position Y.sub.WS in the Y-direction, other geometric properties of the workpiece part 2a, for example the maximum length and the maximum width of the workpiece part 2a, can also be taken into consideration in order for the transfer position Y.sub.UP, or the lateral offset in relation to the central position Y.sub.M of the support slides 14a, 14b to be determined.

(38) Besides the pivoting of the parts chute 17 between the first position S1 and the second position S1 described in the context of FIGS. 2A and 2B, there are also other possibilities for moving the parts chute 17 between the two positions S1, S2, of which in an exemplary manner a plurality of possibilities will be described in more detail in the context of FIGS. 5A and 5B to FIGS. 9A and 9B. FIGS. 5A to 9A show in each case the parts chute 17 in a first position S1, while FIGS. 5B to 9B show in each case the parts chute 17 in a second position S2. The two workpiece bearing faces 4, 5 as well as the second support slide 14b are shown in each case in FIGS. 5A and 5B to 9A and 9B. The cut-free workpiece part 2b bearing on said second support slide in FIGS. 5A to 9A, and said second support slide in FIGS. 5B to 9B having been lowered below the workpiece bearing plane E and relocated in the Y-direction such that the workpiece part 2a drops into the gap 6 and impacts the parts chute 17 that is located in the second position S2, or impacts the chute face 17a of said parts chute 17.

(39) FIGS. 5A and 5B in a manner analogous to FIGS. 2A and 2B show the possibility of pivoting the parts chute 17 between the first position S1 and the second position S2. As opposed to the example shown in FIGS. 2A and 2B the parts chute 17 in the first position S1 forms almost the entire first side wall 20a of the suction box 20. The suction box 20 typically adjoins the respective bearing faces 4, 5 in a flush manner, so as to avoid the egress of cinder, gases, and smoke into the environment.

(40) FIGS. 6A and 6B show an example of a linear horizontal movement of the parts chute 17 between the first position S1 and the second position S2. The parts chute 17 in the example shown, in addition to the inclined chute face 17a, has a wall portion 31 which extends in the Z-direction, that is to say vertically, and which in the first position S1 forms the first side wall 20a of the suction box 20. In the second position S2, displaced into the gap 6, the wall portion 31, which extends in the Z-direction, is brought to bear on the second side wall 20b of the suction box 20 such that the cut-free workpiece part 2a can impact the chute face 17a. The inclined part of the parts chute 17 that includes the chute face 17a can be configured so as to be integral to the wall portion 31; however, it is also possible that the part of the parts chute 17 having the chute face 17a and the wall portion 31 are mutually separable components.

(41) The parts chute 17 in FIGS. 7A and 7B is displaced in the horizontal direction from the first position S1 to the second position S2 in a manner analogous to FIGS. 6A and 6B. However, the parts chute 17 in this case does not form any portion of the sidewall 20a of the suction box 20, but the suction box 20 is lowered so as to enable the movement of the parts chute 17 from the first position S1 to the second position S2 and vice versa.

(42) FIGS. 8A and 8B show an example of a linear movement of the parts chute 17, said movement being performed in the X-direction as in FIGS. 6A and 6B and in FIGS. 7A and 7B. The parts chute 17 in the example shown in FIGS. 8A and 8B is fastened to the upper end of the suction box 20 and can be displaced conjointly with the latter in the X-direction so far that the workpiece part 2a in the second position S2 impacts the chute face 17a of the parts chute 17.

(43) FIGS. 9A and 9B show an example of a linear movement of the parts chute 17 in which the latter in the first position is integrated in a conveyor belt 32 which adjoins the suction box 20. The parts chute 17 in the case of this example is pushed out of the conveyor belt 32 until the parts chute 17 has attained the second position S2 in which the chute face 17a is formed in the gap 6. In the case of the example shown in FIGS. 9A and 9B the parts chute 17 likewise has a vertical wall portion 31, which adjoins the chute face 17a. The vertical wall portion 31 in the case of the example shown in FIGS. 9A and 9B is significantly smaller than the vertical wall portion 31 of FIGS. 6A and 6B and covers an opening in the first side wall 20a of the suction box 20, the parts chute 17 being retracted into the suction box 20 through said opening.

(44) It is understood that the possibility for moving the parts chute 17 between the first position S1 and the second position S2 shown in FIGS. 9A and 9B is optionally possible also without the use of a conveyor belt 32, that is to say using a stationary subarea 32 of the parts chute, as long as the collection carriage 18 is positioned at the transfer position Y.sub.UP only once the parts chute 17 has attained the second position S2.

(45) It is understood that there are possibilities other than those described here in order for the parts chute 17 to be moved between the two positions S1, S2. The parts chute 17 in the first position S1 can also protrude somewhat into the gap 6, for example as is illustrated in the variant shown in dashed lines in FIG. 9A, wherein the wall portion 31 is omitted in this case. The parts chute 17 in this case protrudes into the gap 6 only so far that the parts chute 17 is located outside a movement range 33 of the processing beam 3 in the gap 6, only the extent of said gap 6 in the X-direction being illustrated in FIG. 9A. The time for the movement of the parts chute 17 between the two positions S1, S2 can be reduced in this way.

(46) Alternatively to the collection carriage 18 described in the examples, a conveyor belt can optionally also be used as a receiving unit for the workpiece parts 2a in order for workpiece parts 2a to be moved in the Y-direction along the gap 6. However, further measures are required in this instance for sorting the workpiece parts 2a at different discharging positions, for example the provision of flaps along the conveyor belt which are capable of being pushed or pivoted in and on which the workpiece parts can be wiped from the conveyor belt into parts boxes standing beside the conveyor belt.