CA2762618A1 - Control device for a sliding table saw - Google Patents

Abstract

The invention relates to a control device for a sliding table saw, comprising:
a graphical display unit for displaying operating data to a user, an interface for inputting workpiece dimensions, a control computer in signal communication with the graphical display unit and the interface, for controlling operating data of the sliding table saw.
The invention is characterised in that the control computer is configured to calculate, from the workpiece dimensions received from the interface, in which position and/or orientation the workpiece must be placed on a support surface of sliding table saw, and to transmit data which characterise said position or orientation to the graphical display, and that the graphical display unit is configured to display said position or orientation.

Description

Eisenfuhr Speiser Hamburg, 18 May 2010 Our ref.: AH 326-05CA LBI/aku Direct dial: 040/309 744 25 Applicant/Proprietor: WILHELM ALTENDORF GMBH & CO. KG
Application number: New application Wilhelm Altendorf GmbH & Co. KG
Wettiner Allee 43/45, D-32429 Minden Control device for a sliding table saw The invention relates to a control device for a sliding table saw, comprising a graphical display unit for displaying operating data to a user, an interface for inputting workpiece dimensions, a control computer in signal communication with the graphical display unit and the interface, for controlling operating data of the sliding table saw.
Another aspect of the invention is a sliding table saw comprising such a control device, and a method for controlling a sliding table saw.

Sliding table saws are used to cut large-format workpiece panels, made in particular of wood-based materials, solid wood, plastic or light metal, in order to produce a plurality of workpiece sections of defined dimensions. Sliding table saws of various types are known.
A basic distinction is made between sliding table saws in which the workpiece is guided on a carriage along a rotating saw blade having a fixed axis, and the kind of sliding table saw in which the workpiece is fixated, and the circular saw blade is guided movably and along the workpiece to perform the saw cut. The latter sliding table saws are referred to as panel saws and are known as designs in which the saw blade is guided on a portal above the workpiece support surface, and as designs in which the saw blade is guided below the workpiece support surface.

A very high level of precision can generally be achieved when performing a cut with a sliding table saw. In many designs, the user is supported by a stop fence or other points of reference against which the workpiece can be laid in order to achieve an exactly defined angle and also, if necessary, by flip stops which stipulate a defined measurement in relation to the plane of the saw blade. In order to achieve the desired precision, the user must often adjust the stop fence and the flip stop beforehand to the desired measurement and position and align the workpiece in the desired manner so that the saw cut can subsequently be carried out with the desired precision.

A circular saw apparatus which projects the path of the saw cut onto a surface of a workpiece by means of a laser marking device is known from DE3406904A1. This apparatus permits the path of a saw cut to be carried out to be displayed on the workpiece and is used to take flaws such as knotholes or the like into consideration before performing the cut. However, it does not give the user any assistance by indicating the position and orientation of workpiece panels according to a predetermined cutting plan so that, for example, the user lays the workpiece against a specific edge on a stop fence as envisaged by the cutting plan.

A circular saw apparatus is known from EP1362677B1, which has data input means, a storage and calculation unit and a display unit and which is designed to output on the display unit a numerical value calculated from other fetched numerical values, and to specify the adjustment of a displaceable stop bar for carrying out a slanting cut. This apparatus is aimed at relieving the user of manual calculations involved in making slanted cuts. However, the apparatus is not an improvement in respect of the workflows that are necessary in order to align a panel correctly on the saw tabletop.

In many applications, a large number of workpiece sections are produced from one large-format workpiece, for example a semi-finished product. In such a case, it is desirable to portion such individual workpiece sections within the workpiece in such a way that as little cutting scrap as possible ensues, and that the initial workpiece is thus used in the ideal manner.

It belongs to the prior art to have the user input the dimensions of the desired workpiece sections and then to subdivide the workpiece panel in an optimisation process in such a way that the desired workpiece sections can be cut from the workpiece with maximum avoidance of cutting scrap. With this type of cutting, a predefined pattern of saw cuts ensues which must be complied with, the saw cuts in many cases running parallel to the outer edges, although also at slanting angles to the edges and to each other through the workpiece, if necessary. These saw cuts must be performed successively in order to obtain the desired workpiece sections.

Calculating, positioning, aligning and laying these workpieces and workpiece sections on the workpiece support surface and against the stop fence, or flip stop, generally requires a certain amount of time and therefore delays the workflow as a whole.
Moreover, these operations are liable to result in errors, in that a wrong cut might be carried out due to confusion between workpiece sections, or wrong placement or positioning of workpiece sections.

The aim of the invention is to improve these workflows in respect of both operating safety and operating speed.

This aim is achieved, according to the invention, by the control computer being configured to calculate, from the workpiece dimensions received from the interface, the position and/or orientation in which the workpiece must be placed on a support surface of sliding table saw, and to transmit data which characterise said position or orientation to the graphical display, and that the graphical display is configured to display said position or orientation.

With the control device according to the invention, it is possible to indicate to the user of a sliding table saw the position and/or alignment of a workpiece or workpiece section in an easily understood form on a graphical display unit, before the saw cut is performed on that workpiece or workpiece section.

A workpiece in this context is understood to be an uncut semi-finished material, usually a large-format panel with standard commercial dimensions.

A workpiece section is understood in this context to be a section which is separated from such a workpiece by at least one saw cut. The section may already exist in its final finished dimensions, or must be further subdivided by one or more subsequent saw cuts in order to be cut into workpiece sections having the final dimensions.

The position of a workpiece or workpiece section is to be understood, according to the invention, as the place where a workpiece or workpiece section must be disposed on the workpiece support surface in relation to the circular saw blade, in order for the desired dimension to be produced by the saw cut.

An alignment within the meaning of the invention is understood to be the swivel position of a workpiece or workpiece section about an axis that is perpendicular to its surface.
More particularly, alignment is to be understood as the definition of that lateral edge of a workpiece or workpiece section, which is to be placed against a stop fence in order to perform the following saw cut with the desired dimensions.

The function of a graphical display unit within the meaning of the invention is performed, in particular, by a screen which is fixed, connected or coupled to the control device. The screen may also be disposed on and fixed to a circular saw equipped with the control device of the invention.

Thus, the control device according to the invention can not only calculate the ideal subdivision of a workpiece into a plurality of workpiece sections, but also makes it easier, in particular, to carry out the sequence of saw cuts required for this subdivision of the workpiece with the most efficient timing, and shows the user in each case how he has to position and align the workpiece, or the workpiece sections cut from it, in order to perform the saw cuts successively. It should be understood in this regard that the control computer does not trigger or start the saw cut until the user has given a signal indicating that the workpiece/workpiece section is correctly positioned and aligned. In particular, the graphical display unit may be configured in such a way that it provides a schematic or realistic representation of the workpiece support surface and the edge stop and depicts the workpiece in its dimensions on said workpiece support surface in the required position and alignment. More particularly, it is also possible to display the position of the circular saw blade and/or of a saw slot, to provide a virtual display of the saw cut to be made and also, if necessary, to display the other saw cuts to be subsequently performed, or saw cuts that have already been made. By means of the graphical display unit, it is possible, in particular, to output a schematic or realistic representation of the entire sliding table saw or a section of the sliding table saw together with the workpiece or workpiece section in the position and/or aligned that is being striven for.

In a first preferred embodiment, it is envisaged that the interface for inputting workpiece dimensions includes a user interface by means of which a user can enter workpiece dimensions digitally. This development of the invention makes it possible, in a simple manner, to enter desired workpiece dimensions directly via a user interface provided on the control device and in this way to enter into the control computer the individual panels to be produced from a single workpiece or workpiece section. The user interface may be a numerical keyboard or the like, or it may be designed as an integral part of the graphical display unit, as a touch-sensitive screen, thus providing strong safeguards against failure and a high level of operating safety, particularly in the dust-laden environment of a wood-processing company.

Alternatively or in addition to this development of the invention, the interface is preferably provided with a data interface for inputting workpiece dimensions, by means of which interface workpiece dimensions can be read from an external data source, in particular from a CAD-CAM computer. With this variant of the invention, a preferably standardised data interface is provided, by means of which the control device according to the invention can be connected to a separate planning computer for computer-aided planning and production. In this way, the dimensions and data for a component to be produced, such as a cabinet, a table or the like, can be read beforehand into the planning computer, just as previously in the planning process, and implemented there in order to calculate the positioning and orientation of the workpieces/workpiece sections.

According to yet another embodiment, the control computer is configured to calculate the position and/or orientation for successively performing a plurality of saw cuts on a workpiece, and after performing each saw cut to transmit data to the graphical display which characterise the position and/or orientation of the workpiece for the following saw cut. This development of the invention allows a rapid sequence of steps to be performed on a sliding table saw, in which several saw cuts are performed one after the other, and after each saw cut the positioning and orientation of the workpiece section required for the next saw cut is signalled to the user. As previously explained, the information can be displayed on the graphical display unit in the form of a realistic or schematic visualisation of the workpiece support surface and of the workpiece disposed thereon.

It is further preferred that the control computer be configured to calculate a position to be set for a movable flip stop in order to perform a subsequent saw cut and to output the position via the graphical display unit and/or to actuate an actuator to move the flip stop such that said actuator moves said flip stop to said position. With this development of the invention, adjustment of the flip stop is also made easier for the user by calculating and displaying the positioning and orientation, in that the dimension to be set for the next saw cut is displayed to the user, or, if the flip stop can be moved by means of an actuator, in that the actuator is actuated to move to the required flip stop dimension. A
flip stop in this context is specifically understood to be a longitudinal flip stop which is displaceably disposed on a stop fence and which has a contact surface lying perpendicular to the contact surface on the stop fence.

According to yet another preferred embodiment, the control computer is configured to calculate and to output via the graphical display unit, in a first work step, the position and/or orientation of the workpiece required to perform successive parallel saw cuts, and in a second work step to calculate and to output via the graphical display unit the position and/or orientation of the respective workpiece section required to perform successive parallel saw cuts on the workpiece sections made in the first work step. With this configuration, the control computer calculates what for many applications is a particularly fast manner of working, in which the workpiece must be moved relatively little by the user, in that the sequence of saw cuts is chosen in such a way that saw cuts lying parallel to each other are performed in a first work step, and the workpiece sections produced by these parallel saw cuts are subsequently subdivided.

Alternatively or additionally, the control computer may be configured in another preferred embodiment a. to calculate, in a first work step, the position and/or orientation of the workpiece required to perform a first severing saw cut to sever a first workpiece section, and to output said position and/or orientation on the graphical display unit, b. to calculate, in a second work step, the position and/or orientation of the first workpiece section required to perform at least one saw cut to be performed on said first workpiece sections at an angle to the first severing saw cut on the workpiece section made in the first work step, and to output said position and/or orientation on the graphical display unit, c. to calculate, in an n-th procedure, the position and/or orientation of the workpiece required to perform a further severing saw cut to sever a further workpiece section, and to output said position and/or orientation on the graphical display unit, d. to calculate, in an n+1th procedure, the position and/or orientation of the further workpiece section required to perform at least one saw cut to be performed on said further workpiece section at an angle to the further severing saw cut on the workpiece section made in the n-th work step, and to output said position and/or orientation on the graphical display unit, e. to repeat cuts c. and d. until all the workpiece sections to be made from the workpiece have been cut out.

This configuration avoids the disadvantage that a plurality of workpiece sections have to be placed in interim storage before being fed into subsequent cutting operations. With this configuration, instead, a procedure is adopted in which the final dimensions of the workpiece sections are produced as directly as possible from the workpiece. It is accepted in this regard that multiple positioning and swivelling of workpiece sections is necessary, and that the advantage achieved here is that there is less risk overall of damage to the edges of the workpiece sections, since these are cut directly to their final dimensions and can then be removed from the workpiece support surface.

When the control computer is configured to carry out both of the procedures described above, it is specifically preferred that a user can select, by means of a user interface which is in signal communication with the control computer, whether the control computer is to process a workpiece on the basis of the first sequence of steps as defined above, or on the basis of the second sequence of steps as defined above. This development of the invention allows the user to choose between the one or the other procedure, depending on the arrangement and number of saw cuts and possibly also on the weight and sensitivity of the workpiece being processed, and in this way to adopt the ideal procedure for the respective purpose. It should be understood in this regard that this selection may be made via a separate user interface or via the previously described user interface for inputting processing parameters and workpiece dimensions.

It is further preferred that the control computer is configured to assign a code to every workpiece section produced by performing the saw cuts and to output this code together with the position or orientation of the respective workpiece section on the graphical display unit. Although it is basically preferred that identification of the workpiece sections be made possible by graphical representation of their shape, according to the processing step, this development also achieves non-confusable coding of workpiece sections that have already been cut, in that each workpiece section is assigned a code, for example a number or a letter or an alphanumerical combination, and the code for the workpiece section is displayed in the graphical display unit. The code may also consist of one or more edge lengths of the workpiece/workpiece section. This may be effected in a particularly clear manner such that the code is superimposed directly onto the virtual depiction of the workpiece. Depiction may be further developed in a user-friendly manner by depicting all the workpiece sections that have already been cut, if necessary in a virtual storage room away from the workpiece support surface, and depicted accordingly with their code to provide the user at all times with an overview of the workpiece sections that have been cut.

According to yet another preferred embodiment, the control computer is in signal communication with an actuator for controlling the feed speed between the circular saw blade and the workpiece, and is configured to calculate the position of entry and/or exit of the circular saw blade into or out of the workpiece and to reduce the feed speed on entry of the circular saw blade into the workpiece and/or on exit of the circular saw blade from the workpiece relative to the feed speed between entry and exit. This development allows the control computer, firstly, to start the sawing operation and to regulate the feed rate after detection or signalling of the correct position and orientation of the workpiece/workpiece section. The specific configuration with entry and exit into and out of the workpiece at reduced speed results in improved quality of cut in the region where the saw blade enters and exits the workpiece and prevents chipping of the workpiece at these points. In this regard, it is considered preferable that the control device according to the invention does not require complex sensors to detect with precision the position of the workpiece edges at which the saw blade enters and exits the workpiece, but has already calculated the position of these edges in relation to the path of travel of the circular saw blade, in that the sequence of saw cuts and the positioning and orientation of the workpiece sections are predefined by the control computer in a defined sequence and are subsequently performed accordingly.

According to another preferred embodiment, the control computer is configured to calculate, from workpiece dimensions requiring an angle cut or a mitre cut, the desired position of a flip stop and/or a stop fence and to display said position to the user on the graphical display unit. This development addresses a specific problematic cutting task which generally requires exact calculation by the user operating the sliding table saw.
Mitre or angle cuts are cuts that are carried out with a saw blade swivelled about a horizontal axis, or cuts which are performed in a direction which is not perpendicular to a lay-on edge or workpiece edge or combination thereof. This kind of cut generally requires that several geometrical angles and dimensions be taken into account to determine the correct workpiece dimensions and the resultant cutting dimensions.

According to the invention, this work is made easier for the user of the sliding table saw in that he can enter desired angles and mitres directly and then receive from the control computer, via the display unit, the positioning values for a flip stop or the angle orientations for a stop fence to be set for said mitre or angle cut. It should be understood in this regard that, in the same manner as described above with regard to the flip stop, the respective values and angles can also be adopted automatically by means of the control computer and an actuator, if a respective movement of the stop fence by the actuator is envisaged.

According to another preferred embodiment, the graphical display unit includes a screen which is movable, more particularly which is mounted swivably about a swivel axis, and that the control computer is in signal communication with a sensor, in particular with an angle sensor which detects the position of the screen or the swivel position of the screen about the swivel axis and that the control computer is configured to output the position and/or orientation of the workpiece on the workpiece support surface via the graphical display unit according to a viewing angle like the viewing angle of a user standing in front of the screen in the detected position or swivel position. In many applications, it is desirable to allow the user several different working positions at or around the sliding table saw. In order to allow a view of the graphical display unit from each of these working positions, the graphical display unit can have a swivel screen which can then be swivelled in such a way that its screen surface is arranged perpendicular to the direction in which the user views the screen from the respective working position. In particular, the screen can also be vertically adjustable and displaceable in relation to the workpiece support surface, in order to allow the user a suitable arrangement and orientation of the screen for each processing situation. For this purpose, the screen may be mounted accordingly in relation to the workpiece support surface, for example on suitable guides, rails, swivel arms or similar.

In this development of the invention, to ensure that the display is easy for the user to understand, also in such an arrangement, a depiction is calculated and outputted which corresponds to the angle from which the user views the workpiece support surface, or to the sliding table as seen from the working position, which can be calculated in turn from the position and the swivel angle of the screen. Thus, even when the screen used for output is moved, displaced and/or swivelled between several such positions, the specified orientation and/or positioning of the workpiece on the workpiece support surface is displayed clearly and comprehensibly.

A sensor or angle sensor is provided to detect the position and orientation of the screen.
This sensor may be embodied as a scanning mechanical element connected between the screen and a stationary machine part, for example as an angle sensor working with a rotary potentiometer, and/or as a linear position transducer or the like.
Alternatively or additionally, the sensor or angle sensor may also be embodied as a image scanning unit, for example a digital video camera, and be in signal communication with an image analysis unit in order to determine the position and orientation of the screen on the basis of an image which includes the machine or parts thereof and the screen.

According to another preferred embodiment, a labelling device in signal communication with the control computer is provided, said labelling device being configured to apply a label serving as a code to a workpiece or workpiece section, the control computer being configured to output the code on the graphical display unit and to assign it to the respective workpiece or workpiece section. This labelling device may be individually mobile/displaceable.

Another aspect of the invention relates to a sliding table saw comprising a workpiece support surface and a circular saw blade which is movable relative to the workpiece support surface, the sliding table saw being improved by a control device of the kind described in the foregoing.

Another aspect of the invention relates to a method for controlling a sliding table saw, the method comprising the steps of:

a) entering the workpiece dimensions into a control computer via a user interface, b) calculating by means of the control computer the position and orientation of the saw cuts to be performed, c) displaying on a graphical user interface the position and/or orientation of the workpiece on a workpiece support surface, d) performing a saw cut, if necessary after registering a signal which signals the correct positioning and orientation of the workpiece, e) repeating, if necessary, steps c) and d) until all the saw cuts required have been performed.
This method can be developed either by performing a plurality of parallel saw cuts in a first work step, placing the resultant workpiece sections in interim storage and cutting them to shape in a second work step by one or more saw cuts oriented at a slant, in particular perpendicularly, to the parallel saw cuts, or by severing a workpiece section from the workpiece in a first work step and, in a second work step following immediately afterwards, cutting this workpiece section to shape by one or more saw cuts oriented at a slant, in particular perpendicularly, to the saw cut of the first work step, and repeating this first and second work step in sequence, if necessary, until all the workpiece sections have been produced, wherein the one or the other processing sequence is preferably performed at the discretion of the user.

The method can be further developed, finally, by the user being displayed an adjustment dimension of a flip stop to be adjusted for performing a saw cut, and/or by a flip stop being moved to such an adjustment dimension.

A preferred embodiment of the invention shall now be described with reference to the Figures, in which:

Figs. 1 - 8 show a visualisation sequence of a work step performed on a workpiece panel, Figs. 9 - 13 show a visualisation sequence of a panel subdivision according to a first embodiment of the invention, Figs. 14 - 18 show a visualisation sequence of a panel subdivision according to a second embodiment of the invention, and Figs. 19 - 21 show a visualisation sequence of a cutting operation involving angle cuts.
Fig. 1 shows a monitor screen during the "formatting" work step. What is shown is a panel with basic dimensions of 3,000 x 2,000 mm, from which a workpiece section 20 measuring 1,500x 1,400 mm is to be cut. The dimensions are visualised along the edges of the workpiece, and the saw cuts to be made are visualised by fine lines 31 -34 in the workpiece.

In order to obtain a clean edge on all sides of the subsequent workpiece, trimming cuts 31, 33 are visualised, with which a narrow strip is cut from the edges of the workpiece with a trimming strip width that is designed precisely so that the strip which is cut away cannot fall through the saw slot into the sliding table saw.

As soon as the operator presses the "start" button, the picture shown in Fig.
2 appears, in which the sliding table saw is visualised for the operator with a saw slot 40, a workpiece support surface 50 and a stop fence 60. The laying of workpiece 10 with the position and orientation necessary for making the trimming cut 31 that must first be done is visualised on workpiece support surface 40 and on stop fence 60.

As can be seen in Fig. 3, a visualisation is then displayed which indicates that the panel needs to be positioned in such a way, with a respective advancement in direction A
towards the saw slot, that the trimming cut can then be carried out by moving a circular saw blade 70.

This is followed, as can be seen in Fig. 4, by a visualisation being displayed which indicates that the workpiece can be pushed to the right again by an advancement A so that the first squaring cut 32 can be made.

Fig. 5 shows a visualisation of the situation after the first squaring cut 31, where it is indicated to the user that the severed workpiece section 21 on the left is no longer needed and can be pushed back to the top left onto workpiece support surface 50. It is also indicated to the user that the cut panel 22 lying on the right must be brought back and rotated 90 . This is shown by visualisation of a suitable sequence of rotational positions of said workpiece section 22.

As can be seen from the visualisation in Fig. 6, it is then indicated to the user that workpiece section 22 must now be placed with another edge 23 against the stop fence, in order that the second trimming cut 33 can be made. To this end, the workpiece is pushed to the left by means of feeder carriage 80 a-c until the edge to be trimmed has been detected by a sensor in the region of the saw slot, after which it is moved to the right by a specific amount, and trimming cut 33 is performed.

This is followed by a visualisation being displayed in which the workpiece section is again placed further to the right, and the second squaring cut 34 is performed, which means that part 20 has been cut out completely.

Fig. 9 shows a planning view for cutting a plurality of workpiece sections from one large workpiece panel 110. At the bottom right of the monitor screen, an arrow 100a is shown which points upwards to the right, thus indicating the selection made by the user for a cutting operation according to a first procedure.

In this first procedure, as can be seen in Fig. 10, a trimming cut 131 and three cuts 132-134 parallel thereto are firstly performed in the right-hand part of the workpiece, and the resultant strips 120-122 are visualised in a virtual position in the view displayed. The steps required for this are visualised for the user in suitable form and performed automatically once the user has placed and positioned the workpiece against stop fence 160 in accordance with the visualisation.

This is followed, as shown in Fig. 11, by a visualisation being displayed, according to which the panel must be rotated 90 and placed against edge stop 160 in order to be divided subsequently by a series of parallel cuts resulting in the first, fully-processed workpiece sections 123, 124, which are depicted in final storage position in Fig. 12.

Another 90 rotation of the workpiece and placement of the workpiece against the edge stop is indicated to the user. Saw cuts 135a-g are subsequently performed to obtain the resultant finished parts.

The last work step involves placing strips 120-122 originating from the virtual storage depot back onto the workpiece support surface and indicating this to the operator in an appropriate manner by visualisation, then performing the cuts on these strips to produce the finished parts. The steps required for this are again visualised for the user in suitable form and performed automatically once the user has placed and positioned the workpiece in accordance with the visualisation.

Fig. 14 shows a uniform subdivision of workpiece panel according to a second embodiment of the invention, which is selected by the operator and indicated by the arrow 100a pointing upwards to the left and displayed at the bottom right of the monitor screen.

In this second procedure, as can be seen in Fig. 15, a strip 120 is firstly cut off in the same manner as in the first procedure. However, this is not followed by the other parallel saw cuts being made. Indication is given, instead, that workpiece 125 must be returned directly to the workpiece support surface, in the top left direction, and then, as shown in Fig. 16 , the first severed strip 120 must be rotated 90 and placed against the edge stop, as shown in appropriate visualised form, before the panel is then cut into finished parts 120a,b by advancing it accordingly.

This procedure is repeated for the second strip 121, as shown in Fig. 17, and for the subsequent strips and workpiece sections for which a visualisation for direct cutting into finished parts is displayed, as shown in Figs. 17 and 18.

Fig. 19 shows the production of a triangular workpiece section 220. By entering its geometry and outer contours, the operator firstly describes the workpiece section in terms of its respective angles and dimensions and any other workpiece parameters that may be relevant, such as thickness and type of material. If the panel dimensions are too small for the desired workpiece section, this is signalled to the user in the form of a coloured visualisation.

When the desired workpiece dimensions have been entered, the control computer calculates the required adjustments to be made to the machine and outputs these to the user as values 290a,b for the straight edge and the flip stop. The user can then set the straight edge and the flip stop to the displayed values and cut the angle in the desired manner.

As can be seen from Fig. 20, the user is supported in this activity by the visualisation, in that both the position of a swivable stop fence 261, which must ensue after setting the respective values, and also the positioning and orientation of workpiece 210 at the stop fence are visualised.

Fig. 21 shows the situation when making the second saw cut with which processing of the part is completed.

Claims (15)

1. A control device for a sliding table saw, comprising:
- a graphical display unit for displaying operating data to a user, - an interface for inputting workpiece dimensions, - a control computer in signal communication with the graphical display unit and the interface, for controlling operating data of the sliding table saw, characterised in that the control computer is configured - to calculate, from the workpiece dimensions received from the interface, in which position and/or orientation the workpiece must be placed on a support surface of a sliding table saw, and - to transmit data which characterise said position and/or orientation, respectively, to the graphical display, and in that the graphical display unit is configured to display said position and/or orientation, respectively, to a user.

2. The control device according to claim 1, characterised in that the interface for inputting workpiece dimensions includes a user interface by means of which a user can enter workpiece dimensions digitally, and/or a data interface by means of which the workpiece dimensions can be read in from an external data source, in particular from a CAD-CAM computer.

3. The control device according to any of the preceding claims, characterised in that the control computer is configured to calculate the position and/or orientation for successively performing a plurality of saw cuts on a workpiece and after performing each saw cut to transmit data to the graphical display which characterise the position and/or orientation of the workpiece for the following saw cut, and/or is configured to calculate a position to be set for a movable flip stop in order to perform a subsequent saw cut and to output the position via the graphical display unit and/or to actuate an actuator to move the flip stop such that said actuator moves said flip stop to said position.

4. The control device according to any of the preceding claims, characterised in that the control computer is configured to calculate and to output via the graphical display unit the position and/or orientation of the workpiece required to perform successive parallel saw cuts in a first work step, and to calculate and to output via the graphical display unit the position and/or orientation of the respective workpiece section required in a second work step to perform successive parallel saw cuts on the workpiece sections made in the first work step.

5. The control device according to any of the preceding claims, characterised in that the control computer is configured a. to calculate, in a first work step, the position and/or orientation of the workpiece required to perform a first severing saw cut to sever a first workpiece section, and to output said position and/or orientation on the graphical display unit, b. to calculate, in a second work step, the position and/or orientation of the first workpiece section required to perform at least one saw cut to be performed on said first workpiece sections at an angle to the first severing saw cut on the workpiece section made in the first work step, and to output said position and/or orientation on the graphical display unit, c. to calculate, in an n-th work step, the position and/or orientation of the workpiece required to perform a further severing saw cut to sever a further workpiece section, and to output said position and/or orientation on the graphical display unit, d. to calculate, in an n+1th work step, the position and/or orientation of the further workpiece section required to perform at least one saw cut to be performed on said further workpiece section at an angle to the further severing saw cut on the workpiece section made in the n-th work step, and to output said position and/or orientation on the graphical display unit, e. to repeat cuts c. and d. until all the workpiece sections to be made from the workpiece have been cut out.

6. The control device according to any of preceding claims 4 and 5, characterised by a user interface which is in signal communication with the control computer and via which a user can select whether the control computer is to process a workpiece on the basis of the sequence of steps defined in claim 7, or on the basis of the sequence of steps defined in claim 8.

7. The control device according to any of the preceding claims, characterised in that the control computer is configured to assign a code to every workpiece section produced by performing the saw cuts and to output this code together with the position or orientation of the respective workpiece section on the graphical display unit.

8. The control device according to any of the preceding claims or the preamble of claim 1, characterised in that the control computer is in signal communication with an actuator for controlling the feed speed between the circular saw blade and the workpiece, and is configured to calculate the position of entry and/or exit of the circular saw blade into or out of the workpiece and to reduce the feed speed on entry of the circular saw blade into the workpiece and/or on exit of the circular saw blade from the workpiece relative to the feed speed between entry and exit.

9. The control device according to any of the preceding claims, characterised in that the control computer is configured to calculate, from workpiece dimensions requiring an angle cut or a mitre cut, the desired position of a flip stop and/or a stop fence and to display said position to the user on the graphical display unit.

10. The control device according to any of the preceding claims, characterised in that the graphical display unit includes a screen which is movable, more particularly which is mounted swivably about a swivel axis, and that the control computer is in signal communication with a sensor, in particular with an angle sensor which detects the position of the screen or the swivel position of the screen about the swivel axis, and that the control computer is configured to output the position and/or orientation of the workpiece on the workpiece support surface via the graphical display unit according to a viewing angle like the viewing angle of a user standing in front of the screen in the detected position or swivel position.

11. The control device according to any of the preceding claims, characterised by a labelling device in signal communication with the control computer, said labelling device being configured to apply a label serving as a code to a workpiece or workpiece section, the control computer being configured to output the code on the graphical display unit and to assign it to the respective workpiece or workpiece section.

12. A sliding table saw comprising a workpiece support surface and a circular saw blade which is movable relative to the workpiece support surface, characterised by a control device according to any of the preceding claims.

13. A method for controlling a sliding table saw, comprising the steps:
a. entering the workpiece dimensions into a control computer via a user interface, b. calculating by means of the control computer the position and orientation of the saw cuts to be performed, c. displaying on a graphical user interface the position and/or orientation of the workpiece on a workpiece support surface, d. performing a saw cut, if necessary after registering a signal which indicates the correct positioning and/or orientation, respectively, of the workpiece, e. repeating steps c) and d), if necessary, until all the saw cuts required have been performed.

14. The method according to claim 13, characterised in that - either a plurality of parallel saw cuts are performed in a first work step, the resultant workpiece sections being placed in interim storage and cut to shape in a second work step by one or more saw cuts made slantingly, in particular perpendicularly, to the parallel saw cuts, or - a workpiece section is cut from the workpiece in a first work step and, in a second work step following immediately afterwards, is cut to shape by one or more saw cuts made slantingly, in particular perpendicularly, to the saw cut of the first work step, and said first and second work steps are repeated in sequence, if necessary, until all the workpiece sections have been produced, wherein the one or the other sequence of steps is preferably performed at the discretion of the user.

15. The method according to claim 13 or 14, characterised in that the user is displayed an adjustment dimension of a flip stop to be adjusted for performing a saw cut, and/or in that a flip stop is moved to such an adjustment dimension.