AU2010251160A1 - Plate saw with clamping jaw - Google Patents

Abstract

The invention relates to a plate saw, comprising a workpiece support surface (20a-e) with a sawing slot (10) arranged therein, a sawing aggregate that can be displaced horizontally along the sawing slot (10) and comprises a rotatably mounted chain saw blade, the rotating axis of which being arranged below the workpiece support surface (20a-e), and further comprising at least one workpiece clamping element (80a-c) arranged on an advance carriage (60a-c) that can be displaced in the plane of the workpiece support surface. The workpiece clamping element (80a-c) comprises a mobile clamping jaw (80a-c) which in a first position is arranged below the workpiece support surface, in a second position protrudes the workpiece support surface, on which a surface (81c) is arranged such that said surface serves in the second position as first abutment surface (81c) for a workpiece that is pushed from a first direction, which is oriented parallel to the workpiece support surface, towards the clamping jaw, said clamping jaw being coupled to an actuator such that the actuator exerts a force on the clamping jaw, whereby the clamping jaw is moved from the second position into the direction of the first position, thereby clamping a workpiece in the direction of the workpiece support surface by means of a clamping surface formed on the clamping jaw.

Description

Hamburg, 15 November 2011 Our ref.: AH 325-04AU LBI/aku Direct dial: +49 (0)40 309744-25 Applicant/Proprietor: WILHELM ALTENDORF GMBH & CO. KG Application number: New application Wilhelm Altendorf GmbH & Co. KG Wettiner Allee 43/45, D-32429 Minden Panel saw with clamping jaw The invention relates to a panel saw comprising a workpiece support surface with a saw slot disposed therein, a saw unit which can be moved horizontally along the saw slot and which includes a rotatably mounted circular saw blade the rotational axis of which is disposed below the workpiece support surface, and at least one workpiece clamping element disposed on a feeder carriage which is displaceable in the plane of the workpiece support surface and which can preferably be moved in a direction perpendicular to the saw slot. Such panel saws are used to cut large-format panels, in particular panels made of wood-based materials or solid wood, plastic panels, or panels made of light metals. Panel saws of the kind specified by the invention have a horizontal workpiece support surface onto which the workpiece can be placed by the user or by an automatic feeder mechanism. The workpiece can be displaced on the -2 workpiece support surface, in particular by means of an air cushion or other bearing devices, in order to be positioned in a defined manner relative to the saw unit and its direction of motion. In panel saws of the type specified in the invention, the saw unit is disposed below the workpiece support surface. To perform the cut, a peripheral section of the saw blade is passed upwards from below through the saw slot, and the workpiece can then be cut by moving the saw unit along the saw slot. A panel saw of the kind initially specified is known from EP1990119A1. This panel saw is characterised by having a lay-on edge disposed laterally on the workpiece support surface, by means of which the workpiece can be positioned in a defined manner relative to the saw slot or direction of motion of the saw unit. The prior art panel saw also has fixing and feeder carriages which are fitted with clamping elements for clamping the workpiece panel to be cut to shape and for positioning it by moving the fixing and/or feeder carriages in a defined manner. With panel saws of the kind initially specified, it is basically possible to cut large format workpieces to size in a time-efficient manner. However, it is desirable that such panel saws be further developed so that workpieces can be cut with a variety of dimensions and from panels of various sizes. Another aim is to provide a workflow that is as time-efficient as possible. The object of the invention is to develop a panel saw in such a way that it permits efficient working with workpiece panels of variable dimensions, also and in particular with very small dimensions. This object is achieved according to the invention by the workpiece clamping element having a movable clamping jaw, - which in a first position is disposed below the workpiece support surface, - projects in a second position above the workpiece support surface and -3 - is configured on the one face such that in the second position it serves as a first stop face for a workpiece which is pushed against the clamping jaw from a first direction aligned parallel to the workpiece support surface, and - which is coupled to an actuator in such a way that the actuator exerts a force on the clamping jaw, which moves the clamping jaw from the second direction to the first position, thereby clamping a workpiece in the direction of the workpiece support surface, in particular against the workpiece support surface, with a clamping face embodied on the clamping jaw. By means of the panel saw according to the invention, it is possible to align the workpiece with a face of the clamping jaw and in this way to bring it into a specific and defined position. The stop face on the clamping jaw can only be used in the second position, in which the clamping jaw projects above the workpiece support surface, and in the first position, in which the clamping jaw is lowered to a position below the workpiece support surface or is at least flush with the latter, the stop face is not in the way of displacing the workpiece on the workpiece support surface. By virtue of this specific way of providing a stop face, it is possible for workpieces to be positioned, advanced and cut in a particularly efficient manner, in that it is possible, firstly, to place the workpiece in a defined position at a stop face on the clamping jaw, and then by lowering the clamping jaw into the first position to allow the workpiece to be displaced above the lowered clamping jaw or to clamp the workpiece with the clamping jaw by lowering the clamping jaw in the direction of the first position and subsequently to displace the clamped workpiece and in this way to set a defined cutting dimension. The stop face may be disposed on the clamping jaw in such a specific way that a workpiece which lies against the stop face can be clamped directly by moving the clamping jaw from the first position in the direction of the second position, without any horizontal displacement of the workpiece or the clamping jaw out of the stop position being necessary.

-4 A stop face within the meaning of the invention is understood to be a surface which is oriented in such a way that it references workpieces of any thickness in one and the same position. Such a stop face is preferably perpendicular to the workpiece support surface or has at least one or several perpendicular regions that are flush with one another. In order to lay workpieces with sensitive or fragile side edges in a defined manner against the stop face, without causing any damage or inaccurate positioning, it is preferred that the workpiece edge and the stop face are fully in contact with each other. In certain kinds of application, however, the stop face may be designed in such a way that it forms a linear contact with the workpiece edge or, or even an approximately punctiform contact. The actuator provided in accordance with the invention and which is coupled to the clamping jaw may preferably be an electromagnetic, electromotive, pneumatically or hydraulically driven actuator which delivers a clamping force sufficient for reliably clamping the workpiece. The actuator is also used preferably to move the clamping jaw from the first to the second position and vice versa, and in this way to bring the clamping jaw into the position projecting above the workpiece support surface in order to position the stops, or into the lowered position below or flush with the workpiece support surface in order to displace the workpiece on the workpiece support surface without damaging it. Clamping against the workpiece support surface is understood to mean that the workpiece is clamped against the surface forming the workpiece support surface as counter-surface. This counter-surface may be provided in a fixed position at the panel saw, for example, or it may be movable so that the clamped workpiece can still be moved, for example by moving the clamping jaw with the workpiece clamped therein. The counter-surface can thus be embodied, for example, on the fixing carriage on which the clamping jaw is disposed, so that the workpiece in the clamped position can be moved along with the fixing carriage by moving the fixing carriage. According to a first preferred embodiment of the invention, a second face is embodied on the clamping jaw, which serves as a clamping face for a workpiece and is disposed on the clamping jaw in such a way that a workpiece can be -5 clamped between the clamping face and the workpiece support surface when the actuator moves the clamping jaw out of the second position in the direction of the first position. This configuration makes it possible to lay a workpiece against the clamping jaw in a defined manner and at the same time for the workpiece to be subsequently clamped in this defined position by means of the clamping jaw, which is highly advantageous for an efficient workflow. The clamping face preferably lies in such a way that it has a portion on the opposite side from the workpiece support surface, which is placed onto the upper surface of the workpiece and which then presses the bottom surface of the workpiece onto the workpiece support surface, thus causing the clamping procedure to occur. More particularly, the clamping face may have a rounded shape for a gentle clamping effect on the surfaces of workpieces of different material thicknesses, was is advantageous whenever the clamping jaw is mounted as a swing arm or in some other swivable manner in order to effect the movement from the first to the second position and vice versa. It is further preferred that a third face be disposed on the clamping jaw in such a way that it serves as a second stop face for a workpiece which is pushed against the against the clamping jaw from a second direction aligned parallel to the workpiece support surface and preferably swivelled 180 relative to the first direction. With this development of the invention, two stop faces are provided on the clamping jaw and disposed in such a way that a workpiece can be placed in a defined manner against the clamping jaw from two directions. In this way, it is possible to use the clamping jaw in a universal manner as a point of reference for defined positioning of a workpiece. More particularly, it is also possible with this configuration to position workpieces with large dimensions by means of the first stop face and to position workpieces with small dimensions by means of the second stop face. It is still further preferred that the first stop face lies parallel to and spaced apart from the second stop face. This configuration permits a stop movement along a common directional axis at the two stop faces. The directional axis is preferably parallel to the rotational axis of the circular saw blade, such that the two stop -6 faces lie parallel to the circular saw blade and thus provide a stop member in the advancement direction of the workpiece. It is further preferred that at least one, preferably a plurality of vacuum clamping elements are disposed on the feeder carriage and are arranged in such a way that they can clamp a workpiece lying on the workpiece support surface. In particular, such vacuum clamping elements may be activated by a valve which is actuated by a pin that is pressed in when a workpiece is placed onto the vacuum clamping element. In this case, the workpiece is vacuum clamped to the feeder carriage by the vacuum clamping element, which allows supporting fixing of the workpiece relative to the feeder carriage, thus preventing any unwanted slippage of the workpiece during advancement or when the saw cut is being made. More particularly, the feeder carriage may be designed as an elongate feeder carriage strip, along which a plurality of vacuum clamping elements are located. A particularly preferred embodiment is one in which the feeder carriage can be moved in a direction which is perpendicular to the saw slot. It should be understood in this regard that the feeder carriage can preferably be moved in a direction which is parallel to the workpiece support surface, so that a workpiece clamped in the feeder carriage can be advanced perpendicularly to the circular saw blade and that a desired cutting dimension can be adjusted in this way. The panel saw according to the invention can be further developed by providing a plurality of feeder carriages which each have a clamping jaw with the kind of construction described in the foregoing and which can be moved independently of each other. It is possible with this configuration to align a workpiece against the stop faces of several clamping jaws. It should be understood in this regard that the plurality of feeder carriages can be displaced by means of an actuator and that the stop faces of the respective clamping jaws on the feeder carriage can thus be brought into predefined positions. In this way, a specific angle relative to the saw slot can be set when a workpiece is placed against the stop faces of the clamping jaws. It is specifically preferred in this regard that the stop face is -7 swivably formed on the clamping jaw in order to permit flush contact against the workpiece edge at any angle. Alternatively, in another preferred embodiment, a plurality of feeder carriages may be provided which each have at least one clamping jaw, in particular a clamping jaw in their front end portion facing towards the saw slot and/or in their rear end portion facing away from the saw slot, the feeder carriages preferably being coupled to each other in such a way that they can be moved in common. With this configuration, it is possible by means of the stop faces on the clamping jaws to define a stop line on which the workpiece can be positioned as against a stop edge. By arranging clamping jaws in the end portion of the feeder carriage facing the saw slot, it is possible for narrow workpiece sections to be well clamped and processed. The clamping jaws on the end facing away from the saw slot are used, in contrast, for clamping large-format workpieces and permit the dimensioning of the panel saw to be fully utilised for the workpiece size. In this configuration, the feeder carriages can be directly coupled to each other mechanically, or a control engineering coupling can be provided which synchronously triggers the actuators of the plurality of feeder carriages, thus causing the coupled feeder carriages to move in synchrony. In the latter case, in particular, the control engineering coupling may also be removed and the feeder carriages moved independently of each other in order to thus provide the advantages of the previously described embodiments. It is further preferred that one, and preferably that all of the clamping jaws clamp against a face which is embodied on the respective feeder carriage on which the clamping jaw is disposed. This development of the invention allows a clamped workpiece to be moved in common with the feeder carriage(s) on which the clamping jaws clamping the workpiece are disposed. This is advantageous when the feeder carriages are moved by means of one or more actuators, and then permits the clamped workpiece to be positioned in a dimensionally accurate manner.

-8 In the case of the embodiments featuring a plurality of feeder carriages, it is further preferred that the feeder carriages are parallel to and spaced apart from each other. Such alignment of the feeder carriages results in an advancement that is advantageous for many requirements in respect of saw cuts to be made. The feeder carriages also ensure that the workpiece can be moved in a reliable manner that the operator is able to understand arithmetically. According to another preferred embodiment, the feeder carriage(s) is/are coupled to at least one carriage actuator for moving the feeder carriage(s), and the clamping jaw(s) islare coupled to at least one jaw actuator for moving the clamping jaw(s). This configuration is further characterised by a sensor in the region of the saw slot, said sensor being configured to detect the presence of a workpiece in a region above the saw slot, and by a machine controller which is in signal communication with the saw unit, the carriage actuator, the jaw actuator and the sensor and which is configured to actuate the jaw actuator to clamp a workpiece, move the feeder carriage(s), when the workpiece is clamped, towards the saw slot until the sensor detects the presence of the workpiece in the region above the saw slot, and following that step to actuate the saw unit to perform a trimming cut. This development of the invention allows advantageous automated detection of a workpiece edge which must be cut by means of a trimming cut. A trimming cut is understood here to be a cut in which a narrow strip of material along a rough or undefined workpiece edge is cut away with one saw cut, thus producing a defined and clean workpiece edge. A trimming cut is typically used to define a large format workpiece panel which is to be cut to shape as having a specific length along one edge, and then on the basis of this defined edge to perform further saw cuts parallel or at an angle to said edge. These additional saw cuts are then made at an exact length and angle, clearly determined by the panel saw, to the edge produced by the trimming cut. The machine controller according to the invention works with a sensor, such as a photoelectric barrier which can detect a workpiece above the saw slot.

-9 According to the invention, it is possible with a single sensor or with a plurality of sensors distributed along the saw slot to detect the presence of the workpiece in order, for example, to ensure by means of a plurality of sensors that the workpiece lies above the saw slot along a specific portion of the saw slot. In order to bring the workpiece into such a defined position detected by the sensors, it is firstly clamped by the clamping jaws of the feeder carriages or in some other way and then moved onto the saw slot by moving the feeder carriages. This feeder movement is not stopped until the workpiece lies above the saw slot. The trimming cut can then be performed by moving the saw unit along the saw slot. It is particularly preferred in this regard that the machine controller be configured to move the feeder carriage, with the clamped workpiece, in the direction of the saw slot by a predetermined distance, which can preferably be entered via a user interface, after the sensor has detected the presence of the workpiece in the region above the saw slot, and following that step to actuate the saw unit to perform the trimming cut. This development of the machine controller ensures that the circular saw blade cuts away a strip of material with a specific minimum width when making the trimming cut and hence that its does not run too close to a workpiece edge or even go beyond the side of the workpiece, which can result in a bad trimming cut. The amount by which the feeder carriage is advanced after the workpiece has been detected above the saw cut may be specified or may be programmed by the user, according to the materials being processed, for example, or the thickness of the materials being processed or the size of the saw slot, in order to effect an advancement that cuts away a strip that is sufficiently large not to fall into the saw slot. The machine controller may be specifically configured to calculate, from previously entered workpiece values, for example the type of material and/or the thickness of the workpiece, the advancement that is required for a clean trimming cut, and to perform the trimming cut accordingly. It is still further preferred that the machine controller be configured to actuate the jaw actuator to clamp a workpiece, to move the feeder carriage with the clamped workpiece in the direction of the saw slot as long as the sensor detects the presence of the workpiece in the region above the saw slot, then preferably to - 10 move the feeder carriage with the clamped workpiece in the direction of the saw slot until the sensor detects the presence of the workpiece in the region above the saw slot, then to move the feeder carriage with the clamped workpiece, after the sensor has detected the presence of the workpiece in the region above the saw slot, by a predetermined distance, which can preferably be entered via a user interface, in the direction of the saw slot, and then to move the feeder carriage with the clamped workpiece, after the sensor has detected the presence of the workpiece in the region above the saw slot, by a predetermined distance, which can preferably be entered via a user interface, in the direction of the saw slot, and following that step to actuate the saw unit to perform a trimming cut. Whereas it is necessary, in the previously described embodiments for detecting the edge to be trimmed, that the workpiece be laid down in such a way that it does not cover the saw slot, and the workpiece is subsequently guided to the saw slot, it is possible with this latest preferred embodiment for the workpiece to be laid on the workpiece support surface and be clamped by the fixing carriages in any way one wishes, regardless of whether the saw slot is already covered in the process, or not. The machine controller is then able to move the workpiece into place, depending on the signal from the sensor in the region of the saw slot, in such a way that the edges to be trimmed are detected. This is done by removing the workpiece from the region above the saw slot, if necessary, firstly by moving the feeder carriage away from the saw slot, then advancing it again until the overlap over the saw slot is the amount required for the trimming cut, after which the trimming cut can then be carried out. According to another preferred embodiment of the machine controller provided for carrying out the trimming cut, the machine controller can be configured actuate the jaw actuator to clamp a workpiece, to move the feeder carriage with the clamped workpiece in the direction of the saw slot as long as the sensor detects the presence of the workpiece in the region above the saw slot, then to move the feeder carriage(s) with the clamped workpiece, after the sensor has no longer detected the presence of the workpiece in the region above the saw slot, by a predetermined distance, which can preferably be entered via a user - 11 interface, in the direction of the saw slot, and following that step to actuate the saw unit to perform a trimming cut. With this configuration, if the workpiece is lying above the saw slot after being laid down, it is initially displaced by means of the feeder carriage until it no longer lies above the saw slot, after which it is moved back by a predetermined amount, which may be selected by the user or automatically adjusted by the machine controller, in order to produce sufficient overlapping of the saw slot for a clean trimming cut to be carried out. The panel saw according to the invention may be further developed by coupling the feeder carriage(s) to at least one carriage actuator for moving the feeder carriage(s), coupling the clamping jaw(s) to at least one jaw actuator for moving the clamping jaw(s), and by also providing a machine controller which is in signal communication with the carriage actuator, the jaw actuator and the sensor and which is configured to a) actuate the jaw actuator to clamp a workpiece, b) move the feeder carriage(s) with the clamped workpiece by a cutting dimension which can be entered via a user interface, c) following that step to actuate the saw unit to perform a format cut, and following that step to repeat steps b) and c) if necessary, the feeder carriage being moved by the same or by a different cutting dimension. It is possible with this preferred embodiment to perform one or more cuts on a workpiee that are each carried out according to defined cutting dimensions adjusted by moving the feeder carriage, thus culling a large-format workpiece panel into a plurality of strips of defined width. What is particularly advantageous about this development of the invention is that the operator can program the width and number of strips beforehand via a user interface, and that the panel saw can then perform the required saw cuts automatically and without further intervention by the user. It should be understood in this regard that, before making the first cut to produce the strips, it may be necessary to perform a trimming cut in the manner described in the foregoing, in order to produce a defined reference edge on the workpiece.

-12 Another aspect of the invention relates to a fixing table for a panel saw, comprising a) a workpiece support surface, b) coupling means for fixing the fixing table to a panel saw in such a way that the workpiece support surface of the fixing table lies flush with a workpiece support surface of the panel saw and c) at least one workpiece clamping element disposed on a feeder carriage which can be moved in the plane of the workpiece support surface. According to the invention, the fixing table is characterised by the workpiece clamping element having a movable clamping jaw which in a first position is disposed below the workpiece support surface, projects in a second position above the workpiece support surface, on which one face is embodied in such a way that in the second position it serves as a first stop face for a workpiece which is pushed against the clamping jaw from a first direction aligned parallel to the workpiece support surface, and which is coupled to an actuator in such a way that the actuator exerts a force on the clamping jaw, which moves the clamping jaw from the second direction to the first position, the workpiece thus being clamped by the clamping jaw. Such a fixing table is particularly suitable for being used in combination with a panel saw, in that the fixing table is disposed alongside a workpiece support surface having a saw slot with a circular saw unit therebelow. The fixing table according to the invention is characterised by clamping jaws that can be used both for clamping and as stop faces. For a description of the advantages and manner of operation of these clamping jaws of the fixing table, reference is made to the previous explanations in respect of the panel saw with suitably configured clamping jaws. In addition to use in panel saws, the fixing table according to the invention is also suitable, in particular, for being used with other machine tools, such as sliding table saws with a stationary rotating circular saw blade, processing centres comprising other cutting tools, such as cutting tools or planing tools and the like.

- 13 The fixing table according to the invention can be further developed in a manner similar to that described above for the inventive panel saw and its clamping jaws, feeder carriage and machine controller. Preferred embodiments of the invention shall now be described with reference to the attached Figures, in which Fig. 1 shows a plan view of a first embodiment of a panel saw according to the invention, comprising a fixing table with feeder carriages in a first position, Fig. 2 shows a plan view according to Fig. 1, with the feeder carriage in a second position, Fig. 3 shows a side elevation view of the fixing table of the panel saw shown in Fig. 1, Fig. 4 shows a section from Fig. 3, Fig. 5 shows a perspective view of the upper components of a vacuum clamping element, Fig. 6 shows a detail of a partly cut-away side view showing a vacuum clamping element and a clamping jaw, Fig. 7 shows a detail of a partly cutaway side view according to Fig. 6, in a different sectional plane, Fig. 8 shows a perspective view, seen at an angle from the front and above, of a second embodiment of the invention, and Fig. 9 shows a perspective view, at an angle from above and behind, of the embodiment shown in Fig. 8.

- 14 As can be seen from Fig. 1, a panel saw according to the invention includes a saw slot 10, below which a saw unit (not shown) can move along the saw slot in the direction shown by arrow 13, the saw unit typically projecting upwards out of the saw slot with part of the periphery of the circular saw blade during movement in a first direction, in order to perform the cut, and being disposed completely below the saw slot when moving back in the opposite direction. In the region of saw slot 10, a plurality of sensors (not shown) are disposed which detect the presence of a workpiece above the saw slot. A fixing table is disposed alongside the saw slot. A workpiece support surface is formed by a plurality of air cushion fields 20a-e. Said air cushion fields 20a-d are arranged on the fixing table, whereas air cushion field 20e is disposed at the saw slot. The air cushion fields are provided with a plurality of orifices through which air can escape upwards in order to slightly raise a workpiece placed on the air cushion fields and thus to keep it easily displaceable for exact positioning. In the forward region to the left of the saw cut, a stop bar 30a, b used as a reference surface for laying-on a workpiece is disposed to the side of the workpiece support surface 20a-e. Stop bar 30a, b lies above the workpiece support surface and is perpendicular to saw slot 10. In order to clamp the workpiece to be cut, a total of four saucer-shaped clamping elements are provided along the stop bar in this example. A single clamp 40a is disposed between two stop bar sections 30a and 30b of the stop bar. Two clamping elements embodied double clamps 40b, c are arranged on the immediate left of saw slot 10, and a single clamping element 40d is disposed on the right of saw slot 10 and lies in a line with clamping elements 40b, c. Clamping elements 40a-c are mounted jointly with stop bar 30a,b on a fixing carriage 50 and can be moved in a direction lying in the same plane as the workpiece support surface, which is perpendicular to saw slot 10. Clamping element 40d is stationary and is used to hold that part of a workpiece that remains after cutting.

-15 Three feeder carriages 60a, b, c which can be moved parallel to and in common with the fixing carriage are disposed in the workpiece support surface of the panel saw. Feeder carriages 60a-c are likewise perpendicular to saw slot 10 and are coupled to each other and to fixing carriage 50 by means of a frame (not shown) lying below the workpiece support surface 20a-e, in order to move in common, To effect this movement, a linear actuator 70 is coupled to the frame in the region of feeder carriage 60a which is closest to fixing carriage 50. The surface of each feeder carriage is flush with the workpiece support surface. In this embodiment, each feeder carriage carries a total of nine vacuum clamping elements 61a-c which are used to clamp, by means of a vacuum, a workpiece lying on top of the feeder carriage. In the plane of the workpiece support surface, there is also a plurality of vacuum clamping elements 11 arranged along a line to the left of the saw slot and another plurality of vacuum clamping elements 12 arranged along a line to the right of the saw slot. These vacuum clamping elements are used to fix the workpiece securely during the saw cut. The vacuum clamping elements 12 are also used to hold the part of the workpiece that is separated after the saw cut. A clamping jaw 80a-c is disposed at the end of each feeder carriage 60a-c facing towards the saw slot. Each clamping jaw 80a-c can be swivelled into an upper position, shown in Figures 3 and 4, above the workpiece support surface. A clamping jaw 80a-c is configure in such a way that it can clamp a workpiece lying on the side of the clamping jaw facing towards the saw slot and at the same time provide a defined stop face 81c for that workpiece. Also embodied on the clamping jaw, on the side of the clamping jaw facing away from the saw slot, is a second stop face 82c for a workpiece, against which a workpiece laying on this side of the clamping jaw can be placed. Whereas Fig. 1 shows the panel saw with feeder carriages in an advancement position as close as possible to saw slot 10, feeder carriages 60a-c in Fig. 2 are moved as far away from the saw slot as possible, i.e. to the left in the Figure. By - 16 comparing Figs. I and 2, one can see that feeder carriages 60a-c and fixing carriage 50 with its clamping elements 40a-c and stop bar 30a, b can be moved in common, thus allowing a workpiece in contact with stop bar 30a, b and clamped by means of clamping elements 30a-c and vacuum clamping elements 61a-c to be displaced reliably, without this workpiece moving out of its defined positioning against stop bar 30a, b. One can also recognise that the vacuum clamping elements 11, 12 to the left and right of saw slot 10 can be moved in common with the feeder carriages and the fixing carriage. These vacuum clamping elements are merely used to fix the workpiece in place while the saw cut is being performed, in order to ensure a clean cut and to hold the severed workpiece section subsequently lying to the right of saw slot 10. Fig. 3 shows a side view of the fixing table. The assembly accommodating the circular saw module, saw slot 10, clamping elements 11, 12 and the air cushion field 20e is omitted from Fig. 3. This assembly would be disposed and joined to the fixing table at the position marked 100. Fig. 3 shows the fixing table with feeder carriages 60a-c moved as far as possible to the right towards the saw slot. Stop bar 30a, b can be seen, as can the clamping elements 40b, c arranged as a pair, and a clamping jaw 80c disposed in front of the clamping elements in an extended position above the workpiece support surface. Disposed below the workpiece support surface there is also a fan 90 which serves to deliver air to the orifices in air cushion sections 20a-d. Fig. 4 shows in more detail the section which is circled in Fig. 3. As can be seen, each clamping element 40a-d has a clamping plate 41a-d. Clamping elements 40a-d are retracted, so clamping plates 41 a-d are in their upper position, and a workpiece could be arranged in a space below clamping plates 41a-d and could be pressed against the workpiece support surface, which is substantially formed by air cushion fields 20a-e and the surface of feeder carriages 60a-c. In the region between clamping elements 40a, b, a sensor 42 is disposed which can -17 measure the thickness of the workpiece in order to determine the feed rate of the saw unit and the amount by which the periphery of the saw blade must extend out of the saw slot. As can be seen well in Fig. 4, the clamping jaw 80c shown in the upwardly extended position has a first stop face 81c, against which a workpiece can be laid and positioned in a defined position on the side of the clamping jaw 80c facing towards saw slot 10. Parallel to and spaced apart from the first stop face 81c, a second stop face 82c is disposed on the side of the clamping jaw facing away from saw slot 10. A workpiece can be positioned in a defined position against stop face 82c, on the side of the clamping jaw facing away from the saw slot. Finally, a rounded clamping face 84c opposite workpiece support surface 20a-e is disposed on a clamping jaw arm 83c which projects above the first stop face 81c. When clamping jaw 80c is swivelled about a swivel 85c in an anti-clockwise direction in Fig. 4, clamping face 84c clamps a workpiece on the left of clamping jaw 80c between clamping face 84c and the workpiece support surface 20a-e, Fig. 5 shows in greater detail a vacuum clamping element 61a-c and 11, 12. As can be seen, such a vacuum clamping element has a vacuum plate 62, within and above which a rubber gasket 63 with a circumferential, elastically deformable rim 64 is disposed. Circumferential rim 64 defines an interior vacuum zone in which a plurality of fields 65 are arranged on which the bottom surface of a workpiece comes to lie with frictional engagement when a vacuum is applied to this defined zone. In one corner region of the vacuum clamping element, a sensor pin 66 is disposed which detects a workpiece in the region of the vacuum clamping element and actuates a valve which causes a vacuum to be applied through a plurality of orifices 67 within the zone defined by rim 64. The vacuum clamping element may be attached to the feeder carriage or to the area around the saw slot by means of a central bore 68.

- 18 Fig. 6 shows a cutaway side view of the vacuum clamping element in Fig. 5. It can be seen that the entire vacuum clamping element is inserted inside a frame 69 and can be displaced in the vertical direction inside the frame. This makes it possible for the peripheral rim 64 to be moved into a position below the workpiece support surface when the vacuum clamping element is not being used to clamp a workpiece, so that no damage occurs to the rubber rim 64 of the vacuum clamping element. The vacuum clamping element can be raised from this lowered position when a vacuum is applied, as a result of which it comes into contact with the bottom surface of the workpiece in order to clamp it. In the sectional drawing of the vacuum clamping element in Fig. 7, one can see sensor pin 66, which is shown in the pushed-in position and which is biased by a spring 66' in such a way that it contacts the bottom surface of a workpiece, thus detecting the presence or absence of a workpiece above the vacuum clamping element. By means of the inventive panel saw, it is possible to perform trimming cuts and culling of large-format panels in a particularly simple manner. To perform a trimming cut, a workpiece is placed on the workpiece support surface and positioned against stop bar 30a, b and stop face 82a-c. The workpiece is then clamped by means of vacuum clamping elements 61a-c and clamping elements 40a-c and can be moved with the aid of the feeder carriages and the fixing carriage. When the detectors in the region of the saw slot detect the presence of a workpiece above the saw slot, the feeder carriages and the fixing carriage move to the left, and when the sensors do not detect such a workpiece above the saw slot, the feeder carriages and the fixing carriage move to the right. In this way, the edge of the workpiece can be detected. As soon as the workpiece edge has been detected in the region of the saw slot by means of the sensors, the carriage moves a defined amount to the right over and beyond the saw cut. Vacuum clamping elements 11 clamp the workpiece additionally, and the trimming cut is performed by moving the circular saw module along the saw slot.

- 19 Once such a trimming cut has been made, other formatting cuts can be carried out after releasing vacuum clamping elements 11, by moving the feeder carriage and the fixing carriage by a defined cutting dimension to the right. In this case, clamping elements 11, 12 and clamping element 40d clamp the workpiece to perform the cut, so that the workpiece section to be cut away is likewise fixed securely during and after the saw cut. In the event that a narrow workpiece is to be cut, the workpiece can be clamped in the defined manner against stop face 81 a-c of the clamping jaw, then clamped by means of the clamping jaw and the clamping faces 84c embodied thereon and moved towards the saw slot 10 to perform a cut. Figs. 8 and 9 show a second embodiment of the invention. This embodiment comprises a total of five feeder carriages 160 a-e, which are likewise arranged parallel to one another and recessed within a workpiece support surface 120. Feeder carriage 160 a lies adjacent and parallel to a stop fence 130 at a short distance away from the stop fence. Feeder carriage 160 b lies at an equally short distance adjacent to feeder carriage 160 a. The distance of feeder carriage 160 c to feeder carriage 160 b is greater than the distance between feeder carriages 160 b and a. Feeder carriage 160 d is further apart than the distance between feeder carriages 160 b and c, and the distance between feeder carriages 160 d and e is larger again than the distance between feeder carriage 160 c and d. The distance between feeder carriages 160 a-e is thus increased continuously from stop fence 130. This makes it possible for both small and large workpieces to cover at least two feeder carriages and thus for them to be securely fixed. Each feeder carriage 160 a-e is mounted displaceably along a direction 100, and it should be understood that this displacement of feeder carriage 160 a-c runs perpendicular to the orientation 101 of a saw slot along which a saw blade moves. The saw blade and saw slot provided for it are not depicted in Figures 8 and 9 and would lie in the zone marked with reference sign 110.

- 20 Each feeder carriage 160 a-e has a first clamping jaw 180 a-e at its end which faces the saw slot and which is configured so that it lies in a recessed position below the workpiece support surface 120 and projected above the latter when in a raised position. On each clamping jaw 180 a-e there is a clamping face which faces towards the workpiece support surface white and is disposed such that it can clamp a workpiece lying on the workpiece support surface against a counter surface formed on the feeder carriage. It is possible in this way to clamp a workpiece with one or more clamping jaws 180 a-e and to move it onto saw slot 110 by advancing the feeder carriage, or to move it away from the former. Also disposed on each feeder carriage is a clamping jaw 181 a-e which is placed at the opposite end of the feeder carriage facing away saw slot 110. Clamping jaws 181 a-e are constructionally configured in the same way as clamping jaws 180 a-e. Clamping jaws 181 a-e are used to clamp larger workpieces which cover the entire workpiece support surface or a large part thereof and which are to be cut in such a way that they are placed to extend far in direction 100. Providing two clamping jaws on each feeder carriage, at the respective front and back end of the feeder carriage, makes it possible to clamp not only very narrow workpieces, but also very large workpieces with the feeder carriage and the clamping jaws disposed thereon, and to cut them to shape with the panel saw according to the invention. To do this, it is not necessary that the feeder carriages can be laterally displaced beyond the workpiece support surface. In this regard, it should be understood as a basic principle that when a workpiece is clamped with the rear clamping jaws 181 a-e, the front clamping jaws 180 a-e are in their recessed position below the workpiece support surface and are covered by the workpiece being processed. It should be understood, as a basic principle, that a workpiece is preferably clamped by at least two clamping jaws, although by way of exception a workpiece can also be securely clamped by a single clamping jaw and then processed. According to the invention, a workpiece is clamped, depending on its dimensions, by all those clamping jaws which match its depth perpendicular to -21 the direction in which the stop fence extends and which are reached by the workpiece.

Claims (15)

1. A panel saw, comprising - a workpiece support surface (20a-e) with a saw slot (10) disposed therein, - a saw unit which can be moved horizontally along the saw slot and which includes a rotatably mounted circular saw blade, the rotational axis of which is disposed below the workpiece support surface, - at least one workpiece clamping element (80a-c) disposed on a feeder carriage (60a-c) which is displaceable in the plane of the workpiece support surface, and which can preferably be moved in a direction perpendicular to the saw slot, characterised in that the workpiece clamping element has a movable clamping jaw (80a-c) - which in a first position is disposed below the workpiece support surface, - projects in a second position above the workpiece support surface and - is configured on the one face (81c) such that in the second position it serves as a first stop face (81c) for a workpiece which is pushed against the clamping jaw from a first direction aligned parallel to the workpiece support surface, and - which is coupled to an actuator in such a way that the actuator exerts a force on the clamping jaw, which moves the clamping jaw from the second direction to the first position, thereby clamping a workpiece in the direction of the workpiece support surface, in particular against the workpiece support surface, with a clamping face embodied on the clamping jaw.

2. The panel saw according to claim 1, characterised in that a second face (83c) is embodied on the clamping jaw, which serves as a clamping face (83c) for a workpiece and is disposed on the clamping - 23 jaw in such a way that a workpiece can be clamped between the clamping face and the workpiece support surface when the actuator moves the clamping jaw out of the second position in the direction of the first position.

3. The panel saw according to claim 1 or 2, characterised in that a third face (82c) is disposed on the clamping jaw in such a way that it serves as a second stop face (82c) for a workpiece which is pushed against the clamping jaw from a second direction aligned parallel to the workpiece support surface and preferably swivelled 180* relative to the first direction and that the first stop face (81c) preferably lies parallel and spaced apart from the second stop face (82c).

4. The panel saw according to any of the preceding claims, characterised in that at least one, preferably a plurality of vacuum clamping elements (61 a-c) are disposed on the feeder carriage (60a-c) and are arranged in such a way that they can clamp a workpiece lying on the workpiece support surface.

5. The panel saw according to any of the preceding claims, characterised by a plurality of feeder carriages (60a-c) which each have a clamping jaw (80a-c) and can be moved independently of one another.

6. The panel saw according to any of the preceding claims 1 to 3, characterised by a plurality of feeder carriages (60a-c) which each have at least one clamping jaw (80a-c), in particular a clamping jaw in their front end portion facing towards the saw slot and/or in their rear end portion facing away from the saw slot, the feeder carriages preferably being coupled to each other in such a way that they can be moved in common.

7. The panel saw according to any of the preceding claims 5 or 6, - 24 characterised in that the feeder carriages (60a-c) lie parallel to and spaced apart from one another.

8. The panel saw according to any of the preceding claims, characterised in that one, preferably all clamping jaws clamp against a face which is embodied on the respective feeder carriage on which the clamping jaw is disposed.

9. The panel saw according to any of the preceding claims, characterised in that - the feeder carriage(s) is/are coupled to at least one carriage actuator for moving the feeder carriage(s), - the clamping jaw(s) is/are coupled to at least one jaw actuator for moving the clamping jaw(s), and characterised by - a sensor in the region of the saw slot, said sensor being configured to detect the presence of a workpiece in a region above the saw slot, and - a machine controller which is in signal communication with the saw unit, the carriage actuator, the jaw actuator and the sensor and which is configured to o actuate the jaw actuator to clamp a workpiece, o move the feeder carriage(s), when the workpiece is clamped, towards the saw slot until the sensor detects the presence of the workpiece in the region above the saw slot, and o following that step to actuate the saw unit to perform a trimming cut.

10. The panel saw according to the preceding claim, - 25 c characterised in that the machine controller is configured to move the feeder carriage(s), with the clamped workpiece, in the direction of the saw slot by a predetermined distance, which can preferably be entered via a user interface, after the sensor has detected the presence of the workpiece in the region above the saw slot, and following that step to actuate the saw unit to perform the trimming cut.

11. The panel saw according to the preceding claim 9 or 10, characterised in that the machine controller is configured to - actuate the jaw actuator to clamp a workpiece, to move the feeder carriage(s) with the clamped workpiece in the direction of the saw slot as long as the sensor detects the presence of the workpiece in the region above the saw slot, - then preferably to move the feeder carriage with the clamped workpiece in the direction of the saw slot until the sensor detects the presence of the workpiece in the region above the saw slot, - then to move the feeder carriage with the clamped workpiece, after the sensor has detected the presence of the workpiece in the region above the saw slot, by a predetermined distance, which can preferably be entered via a user interface, in the direction of the saw slot, and - following that step to actuate the saw unit to perform a trimming cut.

12. The panel saw according to the preceding claim 9 or 10, characterised in that the machine controller is configured to - actuate the jaw actuator to clamp a workpiece, to move the feeder carriage with the clamped workpiece in the direction of the saw slot as long as the sensor detects the presence of the workpiece in the region above the saw slot, - 26 - then to move the feeder carriage(s) with the clamped workpiece, after the sensor has no longer detected the presence of the workpiece in the region above the saw slot, by a predetermined distance, which can preferably be entered via a user interface, in the direction of the saw slot, and - following that step to actuate the saw unit to perform a trimming cut.

13. The panel saw according to any of the preceding claims, characterised in that - the feeder carriage(s) is/are coupled to at least one carriage actuator for moving the feeder carriage(s), - the clamping jaw(s) is/are coupled to at least one jaw actuator for moving the clamping jaw(s), and characterised by - a machine controller which is in signal communication with the carriage actuator, the jaw actuator and the sensor and which is configured to a) actuate the jaw actuator to clamp a workpiece, b) move the feeder carriage(s) with the clamped workpiece by a cutting dimension which can be entered via a user interface, c) following that step to actuate the saw unit to perform a format cut, and d) following that step to repeat steps b) and c) if necessary, the feeder carriage being moved by the same or by a different cutting dimension

14. A fixing table for a panel saw according to any of the preceding claims, comprising a. a workpiece support surface, - 27 b. coupling means for fixing the fixing table to a panel saw in such a way that the workpiece support surface of the fixing table lies flush with a workpiece support surface of the panel saw, c. at least one workpiece clamping element disposed on a feeder carriage which can be moved in the plane of the workpiece support surface, characterised in that the workpiece clamping element is embodied as a clamping jaw which has a movable clamping jaw, - which in a first position is disposed below the workpiece support surface, - projects in a second position above the workpiece support surface and - is configured on the one face such that in the second position it serves as a first stop face for a workpiece which is pushed against the clamping jaw from a first direction aligned parallel to the workpiece support surface, and - which is coupled to an actuator in such a way that the actuator exerts a force on the clamping jaw, which moves the clamping jaw from the second direction to the first position, thereby clamping a workpiece against the clamping jaw.

15. The fixing table according to claim 14, characterised by one or more of the features of claims 2 to 13. - 28 Summary The invention relates to a panel saw comprising a workpiece support surface with a saw slot disposed therein, a saw unit which can be moved horizontally along the saw slot and which includes a rotatably mounted circular saw blade the rotational axis of which is disposed below the workpiece support surface, and at least one workpiece clamping element disposed on a feeder carriage which is displaceable in the plane of the workpiece support surface and which can preferably be moved in a direction perpendicular to the saw slot. The invention is characterised by the workpiece clamping element having a movable clamping jaw which in a first position is disposed below the workpiece support surface, projects in a second position above the workpiece support surface, on which one face is configured such that in the second position it serves as a first stop face for a workpiece which is pushed against the clamping jaw from a first direction aligned parallel to the workpiece support surface, and which is coupled to an actuator in such a way that the actuator exerts a force on the clamping jaw, which moves the clamping jaw from the second direction to the first position, thereby clamping a workpiece in the direction of the workpiece support surface, in particular against the workpiece support surface, with a clamping face embodied on the clamping jaw. Fig. 1