Abstract:
The invention relates to waste material removal devices and related assemblies and methods. In certain aspects of the invention, a machining tool has a waste material removal device, which comprises a suction slide for carrying out a movement in a translational direction (x). The suction slide includes a suction arm support and a suction arm, and the suction arm is fastened pivotably on the suction arm support. In certain aspects of the invention, a waste material removal device has a suction arm having a suction opening and a separating device for separating solid waste material parts according to their weight arranged at the suction opening. The suction opening is oriented at an angle between 10° and 170° to a longitudinal axis of the suction arm.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 USC §119(a) from German patent application DE 10 2011 050 749.3, filed May 31, 2011, which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The invention relates to waste material removal devices for machining tools and related methods. 
     BACKGROUND 
     A device having one or more cutting units is known from CH 616 101 A5. The device is assigned to a cutting table. This cutting unit includes a cutting burner and a suction device. An upwardly open suction box, which is movable along a cutting table, is positioned beneath the table. The suction box extends transversely across the width of the cutting table and is attached to the suction device. 
     A laser machining device having a machining table for receiving a workpiece is known from DE 41 30 162 C2. A catching and suction wall is formed below the machining table and extends completely below the supporting element of the machining table. The gaseous and smoke-like waste materials produced are extracted in lateral openings and the waste material parts are caught in the catching tub. 
     A laser cutting device is also known from DE 88 13 739 U1. In that laser cutting device, suction boxes are provided above and below the workpiece support to extract the process gases. These suction boxes are synchronized in terms of their working motion by a control line to the cutting head. 
     DE 35 31 192 A1 describes a flame-cutting table having a suction device for extracting gases which are produced during the flame-cutting process. A movable suction hopper is arranged below a support grate. The hopper extends over the entire width of the support grate and the suction connections thereof open into a movable suction carriage. The flame-cutting table requires a fan of high suction performance. 
     SUMMARY 
     In some aspects of the invention, a machining tool having a waste material removal device provides a suction effect sufficient to extract waste materials using a less powerful fan. 
     In one aspect of the invention, a machining tool has a waste material removal device. The waste material removal device includes a suction slide that includes a suction arm support and a suction arm fastened pivotably on the suction arm support. At least the suction arm of the suction slide can therefore be positioned and operated below the workpiece to be machined in a region below the machining point or directly below the machining point. As a result a relatively small suction cross-section compared to that required in previous waste material removal devices is sufficient to achieve a suction effect. The same or an improved suction effect compared to that of conventional waste material removal devices can therefore be achieved using a less powerful fan. 
     The suction arm may include a device for separating solid waste material parts according to their weight. Only gases, smoke, cinders and small workpiece parts are thus extracted and removed via the suction slide. Larger workpiece parts are not sucked in but remain on the separating device, which can be formed as a deflector, or in particular fall onto a sweep-off plate in the machining tool or onto the base below the machine due to a rapid working motion (e.g., a pivoting motion). Cut workpiece parts of all sizes are thus prevented from falling into suction boxes or suction tubs, as would otherwise be routine in conventional suction devices, and these boxes and tubs therefore do not have to be emptied often and at high frequency, which would require considerable effort. Furthermore, individual components are prevented from remaining on the deflector, on which a cutting beam (e.g., a laser beam), may impinge, whereby unintended welds or damage to the workpiece parts lying thereon could occur. This separating device (e.g., the deflector), may also serve as a heat protection shield for parts lying on the base or sweep-off plate so that a cutting beam emerging from the workpiece on the underside cannot act on the components arranged on the sweep-off plate. These workpiece parts therefore can be easily removed from the machining tool. 
     This deflector can be formed in a planar manner as a flat sheet part and, in particular, can be fastened exchangeably on the suction arm. In particular, simple replacement of the deflector can thus be provided. The suction arm and/or the suction arm support can include a duct for the removal of waste gas. 
     The waste material removal device of the machining tool may have a belt with an opening, which is designed to drive the suction slide in the translational direction and to connect, by means of the opening in the belt, the duct in the suction slide to a fixed suction duct for removal of the waste gas. The suction duct can extend in the X-direction over the entire width of the workpiece support or of a machining area of the machining tool and can be formed as a fixed duct along the longest axis of movement (e.g., the X-axis of the machining tool). 
     The suction slide can be arranged in a self-supporting manner so as to be movable in relation to the suction duct. This makes it possible to pass over an underlying collection chamber for workpiece parts on the base or on the sweep-off plate of the machining tool. 
     A portion of the duct in the suction arm and/or the suction arm support can be arranged concentrically with a pivot axis of the suction arm. Each of the three aforementioned measures (duct for the removal of waste gas, driving belt with an opening, and arrangement of a portion of the duct concentrically with the pivot axis) makes its own contribution to a reliable, compact and well-arranged design with minimal parts and minimal moved mass. 
     The suction slide (e.g., the suction arm of the suction slide), can include a device for separating solid and gaseous waste materials. For example, this separating device can be formed as a baffle plate, which can be provided in the suction arm or in the transition region between the suction arm and the suction arm support. A tubular portion can be provided in the transition region to receive the suction arm pivotably in relation to the suction arm support. 
     The suction slide can include a collection container for temporary storage of solid waste materials. Each of the two aforementioned measures (device for separating solid and gaseous waste materials and collection container for temporary storage of solid waste materials) contribute to preventing small suctioned parts from collecting at points which are not easily accessible or at points at which the collection of small parts is undesirable for other reasons. In addition, small parts therefore are not extracted by the suction slide and do not reach the fixed suction duct. In particular, the collection container for temporary storage is provided in a transition region between the suction arm and the suction arm support. 
     The waste material removal device of the machining tool may have a device which is designed to remove solid waste material parts from the suction arm or suction arm support. For example, this can be achieved by a controllable sweep-off flap. The suction slide can thus be cleaned in an automated manner. 
     The waste material removal device may have a suction arm drive to pivot the suction arm and a pivot drive control to control the suction arm drive. 
     The pivot drive control can be designed to receive a two-dimensional positional indication regarding a machining position of a machining head and, from the two-dimensional positional indication, to produce a command for a suction arm drive to adjust a pivot angle under consideration of the machining position of the machining head in the translational direction. The two-dimensional positional indication can include an indication regarding the machining position of the machining head in the translational direction. Each of the two aforementioned measures (pivot drive control and pivot angle adjustment) contributes to automation of positioning of the suction arm. 
     The pivot drive control can be designed to only change the pivot angle for a subsequent machining position if the new machining position of the machining head would otherwise be located beyond the device for separating waste materials (e.g., the deflector of the suction arm). The suction arm support and the suction arm therefore only need to follow the alternating machining position of the cutting beam (e.g., the laser beam) at reduced speed, amplitude and/or in a delayed manner. The complexity of the assembly, energy consumption, and wear of the assembly can thus be reduced. 
     The waste material removal device of the machining tool can include a contact rail having a longitudinal guide, on which the suction slide forms a thrust bearing. A number of movable, open parts, which are susceptible to contamination, can therefore be reduced and the reliability of the suction system can be increased. 
     Furthermore, a pivot axis of the suction arm can be arranged perpendicular to a machining plane of the machining tool. With a minimum of only two movable axes, the suction opening can thus be positioned suitably for each machining position. In addition, the suction opening in the suction arm can be arranged transverse (e.g., perpendicular) to the machining plane of the machining tool. The workpiece parts are thus prevented from falling directly into the suction arm. 
     In another aspect of the invention, a waste material removal device for a machining tool (e.g., a laser beam machining tool), includes a suction arm with a suction opening, to which a device for separating solid waste material parts according to their absolute weight (i.e., total weight) or specific weight (i.e., weight per volume) is assigned. The suction opening in the suction arm is oriented at an angle between 10° and 170° to the primary longitudinal axis of the suction arm. The primary longitudinal axis of the suction arm is typically oriented parallel to the workpiece support surface or to a machining plane. Due to the opening angle of the suction opening, waste material parts can thus be removed via the separating device and escaping gases, cinders or the like emerging from an underside of the workpiece can also be removed, without the waste material parts falling directly into the suction arm. This allows separation of the waste material parts according to their size or weight. 
     Furthermore, in this waste material removal device, the suction arm is typically arranged pivotably in relation to a suction arm support via a pivot axis. The suction opening and the separating device assigned thereto can thus be positioned below the machining point in the overall machining plane of the machining tool as a result of a simple design measure. Depending on the size of the machining plane, merely the pivoting motion of the suction may be sufficient. With a larger machining plane (e.g., a rectangular machining plane), a suction arm support which receives the suction arm may additionally be arranged movably in a direction of the machining plane. 
     In a further aspect of the invention, a method for waste material removal in a machining tool includes detecting a two-dimensional positional indication of a machining position of a machining head in relation to the workpiece support. The two-dimensional positional indication includes an indication regarding the machining position of the machining head in a machining axis Y. The method further includes establishing a pivot angle of the suction arm based on the machining position of the machining head. The method also includes outputting a command for a suction arm drive to adjust the pivot angle of the suction arm and a command for a path of displacement in the translational direction X for the suction arm support. Positioning of the suction arm and/or of a deflector can be automated. For example, programmed machine control can be used to position the suction arm and/or the deflector. 
     The invention and further advantageous embodiments and developments thereof will be described and explained in greater detail hereinafter with reference to the examples illustrated in the drawings. In accordance with the invention, the features to be inferred from the description and the drawings can be applied individually or together in any combination. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a perspective view of a machining tool; 
         FIG. 2 a    shows a perspective partial view of an embodiment of the machining tool; 
         FIG. 2 b    shows a schematic partial view from above of the embodiment of  FIG. 2   a;    
         FIG. 3  shows a sectional view of the machining tool of  FIG. 2   a;    
         FIG. 4  shows a schematic, perspective view of an exemplary embodiment of a suction arm; 
         FIG. 5  shows a schematic side view of the suction arm of  FIG. 4 ; 
         FIG. 6  shows a perspective view of a detailed region of a suction slide of the machining tool of  FIG. 2   a;    
         FIG. 7  shows a schematic, perspective view of an exemplary embodiment of a suction duct; 
         FIG. 8  shows a schematic side view of the suction duct of  FIG. 7 ; 
         FIG. 9  shows a sectional side view of a guide rail and contact rail of a suction slide of the machining tool; and 
         FIG. 10  shows a flow diagram for a waste material removal method. 
     
    
    
     DETAILED DESCRIPTION 
     A perspective view of a machining tool  10  is illustrated in  FIG. 1 , showing the structure of a laser cutting machine as an exemplary embodiment of a laser beam machining tool. Further exemplary embodiments include, for example, a laser welding machine or a combined punching/laser cutting machine. This machining tool  10  has a CO 2  laser or a solid-state laser as a laser beam generator  2 , a laser beam machining head or cutting head  3 , and a workpiece support  4 . A workpiece  6  is arranged on the workpiece support  4 . A laser beam  5  is generated by the laser  2 . The laser beam  5  is guided to the cutting head  3  from the CO 2  laser with the aid of deflecting mirrors or from the solid-state laser with the aid of a fiber optic cable. The laser beam  5  is directed onto the workpiece  6  by focusing optics arranged in the cutting head  3 . The machining tool  10  is also supplied with cutting gases  7 , for example oxygen and nitrogen. Compressed air or gases specific to the application can be provided as an alternative or in addition. The use of individual gases is dependent on the material of the workpiece  6  to be machined and on the quality requirements of the cut edges. Furthermore, a suction device  8  is provided and is connected to a suction duct  16 , which is located below the workpiece support  4 . 
     When cutting the workpiece  6  with use of oxygen as a cutting gas, the material of the workpiece  6  is generally melted and oxidized. With use of inert gases, such as nitrogen or argon, the material is merely melted. The melt particles produced are then blown off, together with the iron oxides where applicable, and are extracted via the suction duct  16  by the suction device  8 , together with the cutting gas. 
       FIG. 2 a    shows a perspective plan view of an example of a machining tool (e.g. a cutting beam machining tool such as a laser beam machining tool)  10 , having a waste material removal device  12 . Referring to  FIGS. 1 and 2 , the waste material removal device  12  includes the suction device  8  with a fan and a fixed suction duct  16 . The suction duct  16  extends along a machining axis (X-axis) in a translational direction x. The suction duct  16  is arranged substantially parallel to a machining plane  18  (shown in  FIG. 3 ) of the machining tool  10 . Apart from sealing lips or sealing brushes or a belt  84  with winding or return rollers  86 , no flexible parts are required for the suction duct  16 . The remaining parts can be produced from rigid and robust sheets and pipes. The suction duct  16  is subject only to a low level of wear due to the relatively small movements Δx of the suction slide  20 . The flow resistance of the system is minimal. The fixed suction duct  16  typically extends along a longest movement axis (x-axis) of the machining tool  10 . The suction slide  20  can be mounted on the fixed suction duct  16  by a sliding bearing or can be fastened thereon movably by means of a thrust bearing. The belt  84  and/or a contact rail  90  can be formed as part of this bearing assembly. 
       FIG. 2 b    shows a schematic partial view from above of the machining tool  10  of  FIG. 1 . The suction slide  20  has a suction arm support  22  and a suction arm  24 , which is mounted on the suction arm support  22  by a pivot bearing so as to be pivotable about an axis of rotation  26  (shown in  FIG. 4 ). 
       FIG. 3  shows a sectional side view of the machining tool  10 . The suction slide  20  is arranged so as to be movable in a linear manner along the x-axis of the machine. The suction arm support  22  is mounted in a self-supporting manner on the fixed suction duct  16 . A primary longitudinal axis  30  of the suction arm support  22  runs perpendicular to the fixed suction duct  16 . The primary longitudinal axis  30  of the suction arm support  22  extends in a Y-direction of the machining tool  10 , for example over a half-width  32  of a machining area. Alternatively, the suction arm support  22  can also be mounted on both sides of the machining area. 
     A primary longitudinal axis  34  of the suction arm  24  is arranged substantially parallel to the machining plane  18  of the machining tool  10  and is arranged parallel to a plane in which the primary longitudinal axis  30  of the suction arm support  22  is arranged. It is thus possible to arrange a bearing or guide  96  of the suction arm support  22  along one side of the machining tool  10 . This promotes a compact overall design of the machining tool  10  having a waste material removal device  12 . The suction arm  24  is typically articulated above the suction arm support  22 . An articulation below the suction arm support  22 , and even at the same level, is also possible. 
     When carrying out a laser beam machining operation using the machining tool  10 , the waste material removal device  12  carries out a combined linear/pivoting motion (linear motion of the suction arm support  22  and a pivoting motion of the suction arm  24 ), as a result of which a suction opening  42  of the waste material removal device  12  is moved continuously into a position (in relation to a machining position  56  of the laser beam) which is suitable to ensure sufficient suction function. A deflector  46  of the waste material removal device can also be kept constantly below the machining position  56  (dependent on the movement of the laser beam machining head) of the laser beam during the machining operation by the combined linear and pivoting motion. 
     A controller is in communication with the motors that drive cutting head  3  and the suction arm  24 . The controller receives a two-dimensional positional indication regarding the machining position  56  of the cutting head  3 . The two-dimensional positional indication includes an indication regarding the machining position  56  of the cutting head  3  in a machining axis Y. The controller calculates a pivot angle φ of the suction arm  24  (shown in  FIG. 2 ) based on the machining position  56  of the cutting head in the Y-direction. The controller also controls the suction arm drive  38  to adjust the pivot angle φ. 
       FIGS. 4 and 5  show schematic, perspective and side views, respectively of the suction arm  24 . The suction arm  24  includes a suction duct  36 . The suction arm  24  is coupled to the suction arm support  22  and is pivotable about a pivot axis  26 . The pivot axis  26  is arranged substantially perpendicular to the machining plane  18  of the machining tool  10 . The suction arm support  22  has a connecting duct  40 , which connects the pivotable suction duct  36  to the fixed suction duct  16 . 
     Due to the combination of linear movability of the suction arm support  22  along a machining X-axis and the pivotability of the suction arm  24 , all points within the machining area (i.e., the area over which the cutting head  3  can be moved to perform cutting operations) can be reached in a simple and effective manner. The pivoting mechanism does not require any guide rails. The suction arm drive  38  (shown in FIG.  6 ) can be in the form of a pivoting cylinder, chain drive or belt drive or synchronous belt drive that pivots the suction arm  24  about the pivot axis  26 . The pivot bearing for the pivoted articulation can be arranged in a connecting flange  14  between the suction duct  36  and the connecting duct  40 . 
     Still referring to  FIGS. 4 and 5 , the suction arm  24  includes a pivotable suction duct  36 . The suction duct  36  has a suction opening  42  at one end for aspirating waste materials from a machining process. The suction opening  42  encloses an angle β between 10° and 170° (e.g., 90°) with a lower edge  44  of the suction duct  36  or a primary longitudinal axis  34  of the suction arm  24 . 
     The deflector  46  for separating solid waste materials can be attached to the lower edge  44  of the suction duct  36  in the region of the suction opening  42 . The deflector  46  may be plate-like. The deflector  46  (which may also act as a heat protection plate) is located beneath the machining position  56  of the laser beam during operation of the laser machining tool  10 . The deflector  46  is used as a baffle plate to optimize the suction effect for small workpiece parts and gaseous or smoke-like waste materials, and deflects a suction flow and waste materials from the machining process which are to be extracted, in the direction  58  of the suction opening  42 . 
     In the case of conventional suction boxes and suction tubs, the opening for aspiration of the process waste materials extends parallel to the machining plane of the machining tool. In these suction devices, cut workpiece parts and offcuts of all sizes fall into the suction boxes or suction tubs, and these therefore have to be emptied frequently, which is laborious. 
     By contrast, the waste material removal device  12  can be operated in such a way that only gases and/or smoke and/or cinders and/or small workpiece parts are caught by the deflector  46  and drawn into the suction opening  42 . Larger workpiece parts are not sucked in, but remain on the deflector  46  or fall to the base of the machining tool  10 . 
     To clean the deflector  46 , the suction arm  24  can be rotated and/or accelerated so quickly that a centrifugal force of workpiece parts arranged on the deflector  46  overcomes a static friction force of the workpiece parts on the deflector  46  so that the workpiece parts slide off or are shaken off the deflector  46  due to their inertia. Alternatively or in addition, it is also possible to subject the deflector  46  to vibrations by an actuator and/or to fold the deflector  46  about a folding axis  48 , which, together with a surface normal  50  of a broad side  52  of the deflector  46 , encloses an angle γ between 30° and 90° (e.g., between 80° and 90°). For example, the folding axis  48  can run perpendicular or parallel to a longitudinal axis of the suction arm  24 . Workpiece parts which have slid off or which have been shaken off may fall onto the base of the machining tool  10  or onto a sweep-off plate  74  arranged in the tool or may be caught in a catching device. The workpiece parts arranged or caught on the base may be removed from the machining tool  10  during a laser beam machining process or may be removed from the machining tool  10  only after said process. 
     The deflector  46  can be used to absorb laser light radiation or heat, which is produced by the machining process with a laser beam. Parts of the machining tool  10  arranged beneath can therefore be protected against the laser beam or against a heating effect produced by the laser machining. Unintended welding of workpiece parts which have fallen down can thus be prevented, and therefore these parts can be removed more easily from the machining tool  10 . 
     Precise and central positioning of the laser beam on the deflector  46  is not necessary for the absorption effect. It may be sufficient for the cutting beam to contact the deflector  46  generally. It is advantageous if the suction arm  24  does not also have to be moved together with the laser beam, the movements of the laser beam being small compared to the size of the deflector  46 , and if, on the whole, it has to carry out fewer and/or slower movements and/or movements of smaller amplitude compared to a laser machining head, the course of movement of which is typically highly dynamic. The accuracy with which the deflector  46  has to be updated to the machining position  56  of the laser beam during laser machining may be dependent on the size of the deflector  46  (for example on the diameter  54  thereof; see  FIG. 3 ) and/or on the suction properties of the waste material removal device  12  in the region of the suction opening  42  (such as suction performance). If the deflector  46  is arranged fixedly on the suction arm  24  during laser machining, the size  54  of the deflector  46  also determines, indirectly, the extent to which the suction arm support  22  and the suction arm  24  have to follow a changing machining position  56  of the laser beam. 
     For example, the deflector  46  includes a flat plate part, on which at least part of the cutting or laser beam impinges, at least temporarily, during the cutting or laser machining process. If the deflector  46  is subjected to the cutting or laser radiation, it may become worn. Commercially available sheet metal (for example made of steel or of aluminum) can be used to replace this worn part  46  in a cost effective manner. For improved radiation absorption, the sheet metal can be anodized or coated. The user himself of the machining tool  10  can typically cut the deflector  46  to size using the machining tool  10  and can himself replace the deflector according to the level of wear or at predefined intervals. It is possible to provide the deflector  46  with cooling ribs or with a cooling member and/or to cool the deflector on the underside thereof in order to prevent wear. 
     Gases and/or smoke and/or cinders and/or small parts, which are produced by the machining of a workpiece (e.g., a plate-like workpiece), are deflected at the deflector  46  and are sucked into the suction arm  24 . Due to the concentrated suction provided accurately with respect to the machining position in accordance with the invention, the suction performance is greater than that of most conventional waste material removal devices (with identical energy consumption and complexity of the assembly). 
     Referring to  FIG. 5 , the suction arm support  22  or the suction arm  24  may have a collection container  60  for collection and removal of small extracted parts. The collection container  60  can be pot-like or tubular. The collection container  60  prevents small extracted parts from collecting in the suction arm  24 , in the suction arm support  22  or in the fixed suction duct  16  at points which are not easily accessible or at points at which the collection of small extracted parts is undesirable for other reasons. The collection container  60  can be arranged beneath a flow region of the suction duct  36  or of the connecting duct  40  of the suction slide  20  so that the small parts can collect in the collection container  60 . The pivot axis  26  of the suction arm  24  can run centrally or eccentrically through the collection container  60 . 
     A baffle plate  62 , which separates the waste gas from cinders and small parts (for example by changing a flow velocity in the suction flow), may be located above the collection container  60  (for example within a rotary tube). Cinders and/or small parts collect in the collection container  60 . The collection container  60  may be removable and/or may have a pivotable or displaceable cleaning flap  64  on the underside. 
     The suction slide  20  may have a drive  66  for opening and/or closing the cleaning flap  64 . The drive  66  includes a pneumatic cylinder  68  (for example a pushing or pulling short-stroke cylinder). The pneumatic cylinder  68  can be restored by a spring  70 . The drive  66  is fastened to the collection container  60 . A controller can be designed to move the suction arm support  22 , in a cleaning operation mode, into an emptying position so as to open the cleaning flap  64  and deposit waste material collected in the collection container  60  at defined (for example easily accessible) locations. This controller may be different, or the same, as controller which controls the pivot angle φ of suction arm  24 . 
       FIG. 6  shows a perspective view of a detailed region of the machining tool  10 . A sweep-off plate  74  (for example made of high-grade steel) can be inserted in a machine frame beneath the suction slide  20  and can extend below the entire machining area. Parts which have fallen down can be removed from this sweep-off plate  74  more easily than from the floor of a factory building. A sweep-off flap  72  can be attached to the suction arm support  22  or to the suction arm  24  to remove large parts arranged on the base or on the sweep-off plate  74  when the suction slide  20  moves in a sweep-off direction. The sweep-off direction typically coincides with the longest axis of movement x of the machining tool  10 . The sweep-off flap  72  is mounted pivotably (for example can be folded downwardly) on the suction slide  20  and may be controlled by a drive so as to adopt its working position or its idle position. Brushes and/or scrapers can be attached to the underside of the sweep-off flap  72 . The sweep-off flap  72  extends over the entire width Δymax of a machining area. 
       FIG. 7  shows a schematic, perspective view of an embodiment of the suction duct  16 . The fixed suction duct  16  includes a U-profile with flanged tabs. A number of variants are possible for connection of the suction arm support  22  to the fixed suction duct  16 . For example, a longitudinal side  78  (which is otherwise open) of the suction duct  16  can be closed by movable sealing lips or sealing brushes, with which the suction arm support  22  engages by a carriage  80  (shown in  FIG. 3 ) or shuttle. The drive of the suction arm support  22  in a translational direction x can be achieved by means of a rack, a cylinder, a chain or a belt. 
     In an alternative embodiment, the carriage  80  is connected to a belt  84 , which is displaceable in a translational direction x and which closes the (otherwise open) longitudinal side  78  of the suction duct  16 . 
     The belt  84  may include a metal, an alloy, a plastics material, a natural fiber, or a composite material of one or more of the aforementioned materials. In the region of its guide face in the pairing with the material of the counter-face of the suction duct  16 , the belt  84  typically has a sliding friction coefficient μ G  of less than 0.2 (e.g., less than 0.1). The displaceable belt  84  can be a continuously circulating belt, which is guided around return rollers  86  (shown in  FIGS. 1 and 2 ), or a belt  84  which is wound and unwound by winding mandrels. 
     In a region in which the suction slide  20  is connected mechanically to or at least contacts the belt  84 , the belt  84  has a suction opening  88 , through which the aspirated waste materials (in particular a waste gas mixture) can pass. An overall length of the ducts  36 ,  40  and  16  and therefore a suction effect thus remain constant over the entre path of displacement Δxmax. 
     A drive  82  (shown in  FIG. 2 ) can be designed to drive the belt  84 . For example, the belt  84  can be driven by an electric motor and a biased driving roller or a driving pinion. The belt  84  can be designed to drive the suction arm support  22  in a translational direction x. Alternatively, it is possible for a suction arm support  22  driven in another manner in the translational direction x to drive the belt  84 . A mechanical connection between the suction arm support  22  and the belt  84  can be provided by fastening tabs  98 . 
       FIG. 8  shows a schematic side view of the exemplary embodiment of the suction duct  16  with the belt  84  and fastening tabs  98 . 
       FIG. 9  shows a sectional side view of a guide rail  96  and contact rail  90  of the example of the machining tool  10 . One or more guide rails  96  can be arranged in a plane above and/or below a primary longitudinal axis  30  of the suction arm support  22 . 
     The machining tool  10  or a stationary part of the waste material removal device  12  may have contact rails  90  for transferring electrical energy and/or data from and/or to sliding contacts  92  of a tapper  94  of the suction slide  20 . Energy chains can therefore be omitted. Due to a resultant reduction in the number of movable and open parts (that is to say parts which are susceptible to contamination), the reliability of the waste material removal system  12  can be increased. One or more contact rails  90  may be arranged in a plane above and/or below a primary longitudinal axis  30  of the suction arm support  22 . 
       FIG. 10  shows a flow diagram for a waste material removal method  100 . In a first step  110 , a two-dimensional positional indication regarding a machining position  56  of a cutting head is received, wherein the two-dimensional positional indication includes an indication regarding the machining position  56  of the cutting head  3  in a machining axis Y. In a second step  120 , a pivot angle φ of the suction arm  24  (shown in  FIG. 2 ) is calculated under consideration of the machining position  56  of the cutting head in the Y-direction. In a third step  130 , a command for a suction arm drive  38  to adjust the pivot angle φ is generated and output. 
     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.