EP4349530A1 - Fastening device for a workpiece - Google Patents

Abstract

The invention relates to a fastening device for fixing a workpiece to a flat, upright support element, with a main body to which two clamping jaws are movably attached to one another, which extend below the main body and can be moved towards one another by means of a clamping means accessible from the top of the main body. The invention further relates to a set with the fastening device and a plurality of spacer elements for fixing a workpiece to a workbench with a flat, upright support element.The invention is based on the object of providing a fastening device which is simple and inexpensive, which can be securely and flexibly attached to a workbench and with which a workpiece can be securely and easily fixed.To solve the object according to the invention, the fastening device has a holding element which is arranged above the main body and which can be moved towards the main body by means of a clamping means.

Description

Technical area

The invention relates to a fastening device for fixing a workpiece to a flat, upright support element, having a main body to which two clamping jaws are fastened so as to be movable relative to one another, which extend below the main body and can be moved towards one another by means of a clamping means accessible from the top of the main body.

A further aspect of the proposal described here relates to a method for machining a flat workpiece on a water jet cutting system with a work table that has a plurality of flat, upright support elements according to the above description, which are arranged at a distance from one another, wherein the workpiece is placed on a plurality of spacer elements that are distributed over the surface of the workpiece. The proposal described here also relates to a spacer element and a set with at least one fastening device and a plurality of the spacer elements for fixing a workpiece to a work table with a flat, upright support element.

State of the art

Fixing workpieces when machining them ensures that the machining is carried out precisely and in the correct position. This development can be used in particular for fixing workpieces during mechanical machining and especially when cutting the workpiece using a water jet. During water jet cutting, the workpieces rest on the narrow edges of flat support elements that are essentially in a vertical plane and are arranged in a basin that catches the water from the water jet. The support elements are replaceable because they are damaged by the water jet.

From the publication CN113442205A A holding device for fixing a workpiece in a water jet cutting system is known. The holding device comprises a first guide rail, a second guide rail and a plurality of clamping devices. The first and second guide rails are placed on the support elements of the water jet cutting system and fastened to them by means of wing screws. At least one clamping device for fixing a workpiece to be machined is detachably attached to the first and second guide rails. The clamping device comprises a compression spring and a boom pressed onto the workpiece by the compression spring. The fastening device is intended to enable workpieces of different sizes and shapes to be quickly clamped and released in a water jet cutting system.

Summary of the invention

The invention is based on the object of providing an easy-to-use fastening device. The fastening device should preferably be designed simply and inexpensively, be able to be attached to a workbench safely, quickly and flexibly and fix a workpiece securely and easily to the workbench.

According to the invention, this object is achieved by a fastening device having the features of the independent claims. Advantageous embodiments emerge from the dependent claims.

The fastening device described here for fixing a workpiece to a flat, upright support element comprises a main body to which two clamping jaws are fastened so as to be movable relative to one another, which extend below the main body and can be moved towards one another by means of a clamping means accessible from the top of the main body.

The flat, upright support elements are usually vertically oriented metal sheets and are also referred to as wear plates. As mentioned above, the work table of a water jet cutting system has a basin for collecting the water with a plurality of such support elements, which lie essentially in vertical planes and whose upper edge, remote from the support table, forms the support for a workpiece. Alternatively, the support element can also be a rod, a rib or a grid, wherein the rod, the rib or the grid has an edge pointing away from the work table on which the workpiece rests.

The fastening device can be fastened to the support element by means of the clamping jaws in such a way that the main body is placed on the edge of the support element that is furthest from the work table and is fastened to it with the clamping jaws. A workpiece to be machined is often plate-shaped and flat and is aligned horizontally for machining. For this purpose, the main body is attached to the edge of the support element that is furthest from the work table. Support element, and the clamping jaws rest against two side surfaces of the support element adjacent to this edge and clamp the support element. The two clamping jaws are attached to the main body so as to be movable relative to one another and protrude at least partially from beneath the main body. The clamping jaws are moved towards or away from one another by means of a clamping means which is accessible from the top of the main body, in order to be moved from a clamping position with a small distance between the clamping jaws to a release position with a large distance between the clamping jaws. In the clamping position, the fastening device is clamped to the support element and can be removed therefrom in the release position. The top of the main body is the side of the main body facing away from the support element. For example, the workpiece to be machined can be placed on the top. The clamping jaws can be moved together by means of a single clamping means acting on both clamping jaws. Alternatively, two separate - for example identical - clamping means accessible from the top of the main body can be provided, wherein each of these two clamping means can move a clamping jaw between the clamping position and the release position.

To achieve the object according to the invention, the fastening device has a holding element which is arranged above the main body, i.e. on the side of the main body remote from the clamping jaws, and which can be moved towards the main body by means of a clamping means. In other words, a holding element is proposed with which a workpiece to be machined and arranged at least partially below the holding element can be pressed against the main body or against the support element. The holding element is in particular flat and protrudes above the top of the workpiece by less than 2.5 mm, preferably less than 2 mm. The holding element can be smaller than the top of the main body or essentially congruent with it. In both of these cases, the workpiece to be fixed can be pressed against the top of the main body by the holding element. Alternatively, the holding element can be larger than the top of the main body. In this case, the holding element protrudes laterally beyond the main body and can press the workpiece to be fixed against the support element and/or against the top of the main body. The force with which the workpiece is pressed against the main body and/or against the support element is caused by the clamping device. For this purpose, the clamping device pushes or pulls the holding element in the direction of the main body. The clamping device is connected to the main body with a first section. This connection can be realized in a material-locking, form-locking and/or force-locking manner. The clamping device is connected to the holding element with a second section. This connection can also be implemented in a material-locking, form-fitting and/or force-locking manner. A plurality of - for example identical - clamping devices with the features described above can also be used, with which the holding element can be moved towards the main body. The clamping device or the plurality of clamping devices can also be designed, arranged and connected to the holding element in such a way that no area of the fastening device protrudes by more than 2.5 mm, preferably 2 mm, beyond the side of the workpiece facing away from the main body. Overall, the fastening device is thus arranged essentially below the workpiece to be machined. A tool for machining the workpiece, in particular a nozzle of a water jet cutting system, is often moved at a distance of a few millimeters over the side of the workpiece facing away from the main body. This distance is often less than 3 mm. Due to the design of the fastening device, which is mainly arranged below a workpiece to be machined and only has a flat holding element above the workpiece, it is possible to move the tool freely above the workpiece. This reduces or eliminates the risk of the tool colliding with the fastening device and becoming damaged when moving above the workpiece.

In practice, a gap can be formed between the clamping jaws in a first plane and a gap can be formed between the holding element and the top of the main body in a second plane, the second plane being oriented at right angles to the first plane. The two gaps oriented at right angles to each other allow workpieces to be machined to be fixed in a horizontal orientation with the fastening device when the fastening device is attached from above to a support element that protrudes vertically from a horizontal work table. This is the case, for example, in water jet cutting systems in which the work table has a tub or basin for collecting the water in which the flat support elements extend vertically upwards. The fastening device can also be used with flat support elements that do not extend exactly vertically. In this case, "below" means close to the work table and "above" means away from the work table.

In practice, the clamping means can be a clamping screw. The clamping screw has a connecting element and a threaded area. The connecting element, also called a rotary drive, is used for the positive connection with a tool for turning the clamping screw, e.g. a screwdriver or wrench. The connecting element can be slot-shaped or Phillips-shaped, it can be shaped as a hexagon socket or six-tooth (TORX ^® ). It can also be a square or hexagon projection for a wrench. The clamping screw The threaded area extends through a hole that extends through the main body and has an internal thread. Using the connecting element on the top of the main body, the clamping screw can be turned from the top and thus screwed into and out of the hole. The clamping screw can also have a driver. The driver is then arranged at the end of the threaded area that is opposite the connecting element. The clamping screw uses the driver to engage behind a recess that is optionally made in the clamping jaws. The recesses in the clamping jaws are essentially geometrically complementary to the driver. The recesses can be provided on the sides of the clamping jaws that face each other, so that the clamping jaws rest with these sides against the clamping screw arranged in the main body. By screwing the clamping screw into the internal thread of the hole in the main body from the top, pressure is exerted on the clamping jaws via the driver, which pushes the clamping jaws apart into the release position. By unscrewing the clamping screw from the main body upwards, a tensile force is exerted on the clamping jaws via the driver, which moves the clamping jaws towards each other in the clamping position. However, a driver on the clamping screw is not absolutely necessary. For example, the clamping screw can have a stump or a tip at the end of the threaded area opposite the connecting element, with which the clamping screw rests against an edge of each of the two clamping jaws pointing in the direction of the main body surface. In this case, by screwing the clamping screw into the internal thread of the hole in the main body, pressure can be exerted on the clamping jaws from the top, which pushes the clamping jaws apart into the release position. The clamping jaws can be moved towards each other in the clamping position, for example, by unscrewing the clamping screw from the main body upwards and by means of elastic springs which press the clamping jaws towards each other. Optionally, it is also possible to use two clamping screws, with each of the clamping screws having a driver, a stump or a tip and interacting with one of the two clamping jaws. For example, a clamping screw with a stump at the end of the threaded area opposite the connecting element can press on an upwardly facing edge of one of the two clamping jaws. In this case, by screwing the clamping screws into the internal thread of the hole in the main body, pressure can be exerted on one of the clamping jaws from the top, which pushes the clamping jaws towards each other, for example into the clamping position. The clamping jaws can be moved away from each other into the release position, for example, by unscrewing the Clamping screws extend upwards from the main body and are operated by means of elastic springs which push the clamping jaws apart.

In practice, the clamping jaws can be pivotably attached to the main body. By pivoting the clamping jaws about pivot axes, it is possible to move the sides of the clamping jaws facing each other away from each other or towards each other and to adjust the release position or the clamping position. For this purpose, both clamping jaws or only one of the two clamping jaws can be pivotably arranged. In particular, the clamping jaws can have separate pivot axes. The clamping means can then engage the clamping jaws in particular in an area lying between the pivot axes.

In a practical embodiment, the main body can have a recess in which the clamping jaws are arranged. The recess is made in a lower side of the main body, which is opposite the upper side, and is formed at right angles to the upper side. In particular, the recess can be a slot, i.e. a narrow, elongated recess in a plane in which the clamping jaws are at least partially arranged. By introducing the pivotable clamping jaws into a slot in the main body, the clamping jaws are guided on the main body and the risk of a user of the device pinching their fingers is reduced. The main body can additionally have a second slot that runs at right angles to the first slot and at right angles to the upper side. A gap is formed between the clamping jaws in a clamping plane, in which the flat support element can be clamped. The clamping plane can coincide with the plane of the second slot, so that the second slot guides the support element into its intended position between the clamping jaws. The main body can then be placed with the second slot on the upper edge of the support element and clamped to the support element with the clamping jaws arranged in the first slot.

In practice, the clamping jaws can have a sawtooth profile on the sides facing each other. The sawtooth profile makes it particularly safe to attach the fastening device to the support element because the saw teeth of the sawtooth profiles rest against the support element with high surface pressure in the clamping position.

In practice, the holding element can be attached to the top of the main body so as to be displaceable in a direction perpendicular to the top. The displaceable Fixing the holding element allows workpieces with different thicknesses to be fixed between the top of the main body and the holding element.

The realization of the movable fastening of the holding element is particularly simple in practice if the holding element is fastened to the main body by means of an elastic clamping device, for example a tension spring or bending spring, which pulls the holding element towards the top of the main body, wherein the main body has an inclined guide surface opposite the underside of the holding element, which defines an insertion gap with the underside of the holding element that runs at an angle to the direction of displacement. A workpiece to be machined, for example a metal plate, wooden plate or plastic plate, can be inserted at an angle into the insertion gap and, when the workpiece is pivoted down into a plane running at a right angle to the direction of displacement, lifts the holding element in relation to the main body and enlarges the gap. The elastic clamping device counteracts the lifting and thus fixes the workpiece to the fastening device.

In a further practical embodiment, the clamping jaws can each have a projection on the sides facing away from each other. The projections serve as levers by means of which the clamping jaws can be pivoted from the clamping position into the release position. Manually operating the levers after releasing the clamping means moves the clamping jaws from the clamping position into the release position and enables the main body to be removed from the support element.

In practice, clamping jaws that are pivotably attached to the main body can be mounted in plain bearings, particularly plain bearings with solid friction. The plain bearings ensure smooth pivoting between the release position and the clamping position. In addition, plain bearings are durable and easy to clean.

Additionally or alternatively, the clamping jaws can in practice be made of a material with higher strength than the material of the main body. This reduces the wear of the mechanically stressed clamping jaws and increases the service life.

A further aspect of the invention relates to a method for machining a flat workpiece on a water jet cutting system with a work table which has a plurality of flat, upright support elements according to the above description, which are arranged at a distance from one another, wherein the workpiece is placed on a plurality of spacer elements which are distributed over the surface of the workpiece. Each of the spacer elements comprises a lower slotted area, into the slot of which a support element is inserted, and a second unslotted area, on the free end surface of which the workpiece rests.

Furthermore, the proposal described here relates to the spacer element described above and to a set for fixing a workpiece to a work table with a plurality of flat, upright support elements, comprising at least one fastening device according to the above description and a plurality of the spacer elements, i.e. two or more spacer elements. If the spacer element has a small, approximately point-shaped upper end surface for supporting the underside of the workpiece, at least three spacer elements should be used. Three points define a surface. If the upper end surface of at least one spacer element extends over a greater length, two spacer elements may be sufficient. With such long spacer elements, however, there is a risk that they will be destroyed by the water jet, whereas point-shaped spacer elements can be placed in such a way that only a few or no spacer elements are cut by the water jet.

The spacer elements are used to create a gap between the underside of the workpiece and the support element. When cutting a workpiece with a water jet, the water rebounds from the upper edge of the support element when the water jet is guided over a support element and can hit the underside of the workpiece. With sensitive workpieces, such as decorative wood or acrylic glass, there is a risk that their underside will be damaged by water rebounding from the support elements. By placing the spacer elements on the support elements and the resulting gap between the underside of the workpiece and the upper edges of the support elements, it is ensured that the kinetic energy of the rebounding water when it hits the underside is sufficiently low to prevent damage to the underside. By fixing the workpiece with the fastening device, the workpiece is held securely, and by the workpiece resting on the spacer elements, the workpiece is evenly supported. Thanks to the combination of the fastening device and the spacer elements, the workpiece maintains its specified position above the work table during processing, so that it can be processed precisely and damage to the underside by rebounding water is excluded.

In practice, the length of the unslotted areas of all spacer elements can be the same. This creates a level above the level of the Edges of the support elements are clamped onto which a workpiece can be placed with a flat side. In particular, the length of the unslotted areas of all spacer elements can also be identical to the distance between the top of the fastening device and the edge of the support element to which the fastening device is attached.

In practice, the spacer elements can be tubular. A slot can then be made in a lower end face of the tube at a right angle to the end face. The end face opposite this end face is the free end face of the unslotted area. The workpiece is placed on this free end face. Tubular spacer elements are compact and offer the advantage of being able to be placed on the wear plates with particular flexibility. If the cutting pattern of a workpiece to be machined is known, it is possible to position the spacer elements in such a way that a water jet machining the workpiece is guided past the spacer elements. This means that the destruction of the spacer elements can be avoided.

In this context, reference is also made to the possibility of visualizing the cutting path before machining a flat workpiece on a water jet cutting system by means of an optical image of the machining pattern, in particular a cutting pattern to be produced. The machining pattern can be projected onto the work table or onto the workpiece resting on it using a light beam, in particular a laser beam. Based on the projected cutting image, it is possible to predict which area will not be cut by the water jet. The workpiece to be machined can then be aligned with the cutting image, e.g. when a wooden workpiece is being machined and the grain is to be matched to the cutting path. The fastening device and/or the spacer elements on which the workpiece rests can be arranged and positioned relative to the machining image in such a way that they do not lie on a cutting line and are not damaged by the water jet.

As an alternative to a tubular design of the spacer elements, the spacer elements can in practice be designed in the shape of strips, whereby the spacer elements designed as strips have a lower slotted area with which a strip can be placed over a significant part or the entire length of a straight support element (also called a wear plate). By using strip-shaped spacer elements, a workpiece can be securely supported with just two spacer elements. Only a few spacer elements need to be placed on the wear plates, which means that the process can be carried out particularly quickly.

In practice, the spacers can be made of plastic. Plastic is particularly cheap and easy to process. At the same time, the strength of most plastics is high enough to be able to bear the load of a workpiece. However, wooden tubes, e.g. made of bamboo, can also be used.

In practice, in the method for machining the workpiece on a water jet cutting system, the workpiece can be fixed with at least one fastening device as described above, wherein the fastening device is clamped onto a support element. This means that the workpiece is securely stored and can be machined precisely.

Short description of the drawings

• Fig. 1 zeigt eine perspektivische Ansicht einer Befestigungsvorrichtung gemäß einer ersten Ausführungsform von schräg unten.
• Fig. 2 zeigt eine perspektivische Ansicht der Befestigungsvorrichtung aus Fig. 1 von schräg oben.
• Fig. 3 zeigt eine geschnittene Seitenansicht der Befestigungsvorrichtung aus Fig. 1.
• Fig. 4 zeigt eine geschnittene Vorderansicht der Befestigungsvorrichtung aus Fig. 1.
• Fig. 5 zeigt eine perspektivische Ansicht einer Befestigungsvorrichtung gemäß einer zweiten Ausführungsform von schräg oben.
• Fig. 6 zeigt eine geschnittene Vorderansicht der Befestigungsvorrichtung aus Fig. 5.
• Fig. 7 zeigt eine perspektivische Ansicht eines Distanzelements, das mit der Befestigungsvorrichtung aus Fig. 1 in einem Satz zusammenwirken kann.
• Fig. 8 zeigt eine perspektivische Ansicht eines weiteren Distanzelements.
• Fig. 9 zeigt eine perspektivische Ansicht eines weiteren Distanzelements.
• Fig. 10 zeigt eine perspektivische Ansicht eines weiteren Distanzelements.
• Fig. 11 zeigt eine perspektivische Ansicht eines weiteren Distanzelements.
• Fig. 12 zeigt eine perspektivische Ansicht eines weiteren Distanzelements.
• Fig. 13 zeigt eine erste perspektivische Ansicht einer Verschleißlamelle mit Distanzelement gemäß Fig. 7 und Befestigungsvorrichtung gemäß Fig. 1.
• Fig. 14 zeigt eine erste perspektivische Ansicht einer Verschleißlamelle mit Distanzelement gemäß Fig. 7 und einer weiteren Ausführungsform einer Befestigungsvorrichtung.
• Fig. 15 zeigt eine freigestellte perspektivische Ansicht der Befestigungsvorrichtungen aus Fig.14.
• Fig. 16 zeigt eine Schnittdarstellung der Befestigungsvorrichtungen und des Distanzelements aus Fig. 14 beim Anbringen eines Werkstücks.
• Fig. 17 zeigt eine der Fig. 16 entsprechende Darstellung mit in die Bearbeitungsposition verschwenktem Werkstück.
• Fig. 18 zeigt eine Draufsicht auf einen Werktisch zur Bearbeitung eines Werkstücks mit Distanzelementen und Befestigungsvorrichtungen.
• Fig. 19 zeigt eine perspektivische schräge Draufsicht der Anordnung aus Fig. 18.

Further practical embodiments and advantages of the invention are described below in connection with the drawings.

• Fig.1 shows a perspective view of a fastening device according to a first embodiment obliquely from below.
• Fig.2 shows a perspective view of the fastening device from Fig.1 from above.
• Fig.3 shows a sectioned side view of the fastening device from Fig.1 .
• Fig.4 shows a sectioned front view of the fastening device from Fig.1 .
• Fig.5 shows a perspective view of a fastening device according to a second embodiment obliquely from above.
• Fig.6 shows a sectioned front view of the fastening device from Fig.5 .
• Fig.7 shows a perspective view of a spacer element which is connected to the fastening device of Fig.1 can work together in one sentence.
• Fig.8 shows a perspective view of another spacer element.
• Fig.9 shows a perspective view of another spacer element.
• Fig.10 shows a perspective view of another spacer element.
• Fig. 11 shows a perspective view of another spacer element.
• Fig. 12 shows a perspective view of another spacer element.
• Fig. 13 shows a first perspective view of a wear plate with spacer element according to Fig.7 and fastening device according to Fig.1 .
• Fig. 14 shows a first perspective view of a wear plate with spacer element according to Fig.7 and a further embodiment of a fastening device.
• Fig. 15 shows a cut-out perspective view of the fastening devices from Fig.14 .
• Fig. 16 shows a sectional view of the fastening devices and the spacer element from Fig. 14 when attaching a workpiece.
• Fig. 17 shows one of the Fig. 16 corresponding representation with the workpiece swiveled into the processing position.
• Fig. 18 shows a top view of a workbench for machining a workpiece with spacers and fastening devices.
• Fig. 19 shows a perspective oblique top view of the arrangement of Fig. 18 .

Description of the embodiments

The Figures 1 to 4 show a first embodiment of the fastening device in different views. The Figures 5 and 6 shows a second embodiment of the fastening device. The Figures 7 to 12 show spacer elements that are preferably used in combination with the fastening device made of Fig. 1 to 4 be used. The Figures 13 to 18 explain the interaction of the fastening devices and the spacer elements. In the drawings, identical elements or elements with the same function are designated with the same reference symbols.

With the Figures 1 to 4 With the fastening device 1 shown, a workpiece 2 can be fixed to a flat, upright support element 3 of a work table, as is shown, for example, in Figure 13 The support element 3 is a flat sheet of metal or plastic, which has a flat upper edge, onto which the workpiece 2 is often placed directly in machining processes known from the prior art. Such support elements 3 are referred to as wear plates in water jet cutting. The wear plates 3 are generally located in a water basin or catch basin, which forms the work table of a water jet cutting system. As an alternative to a plurality of parallel wear plates 3, it is also known to use intersecting support elements which form a grid.

The fastening device 1 has a main body 4, to which two clamping jaws 5a, 5b are movably attached to one another. The movable fastening of the clamping jaws 5a, 5b is carried out by means of sliding bearings 6a, 6b attached to the main body 4, in which the clamping jaws 5a, 5b are each mounted so as to be able to slide around a pivot axis. By pivoting the clamping jaws 5a, 5b, the clamping jaws 5a, 5b can be moved towards one another into a clamping position and away from one another into a release position. A gap 7 is formed between the clamping jaws 5a, 5b in a first plane. If the sides of the clamping jaws 5a, 5b facing one another are aligned essentially parallel to one another, the thickness of the gap 7 between them corresponds approximately to the thickness of the support element 3.

The clamping jaws 5a, 5b partially protrude from below the main body 4 and thus extend at least partially below the main body 4. However, a larger section of the clamping jaws 5a, 5b is arranged in a recess 8 in the main body 4. The recess is designed in the form of a first slot 8. The first slot 8 defines the plane in which the clamping jaws 5a, 5b can pivot. The width of the first slot 8 corresponds approximately to the thickness of the clamping jaws 5a, 5b transversely to their direction of movement. The clamping jaws 5a, 5b and the sliding bearings 6a, 6b in which the clamping jaws 5a, 5b are mounted are protected from contamination by the arrangement within the slot 8. In addition, the risk of a user pinching their fingers with the clamping jaws 5a, 5b is reduced.

In Figure 4 the representation of the clamping jaws 5a, 5b is divided along the center plane of the gap 7, shown by a dot-dash line. The left clamping jaw 5a is shown in the release position and the right clamping jaw 5b in the clamping position. A second slot 9 is formed in the main body 4 at right angles to the first slot 8. The second Slot 9 is located in the same plane as the gap 7 between the clamping jaws 5a, 5b. The width of the second slot 9 is selected such that the support elements 3 can be inserted unhindered into the second slot 9.

The clamping jaws 5a, 5b are moved by means of a clamping means designed as a clamping screw 11 that is accessible from the top 10 of the main body 4. The clamping screw 11 extends through a bore 12 with an internal thread in the main body 4 that extends from the top 10 of the main body 4 to the first slot 8. The clamping screw 11 has a threaded area with an external thread with which it can be screwed into or out of the bore 12 with respect to the top 10. The upper end of the clamping screw 11 is designed as a grub screw and can be screwed completely into the bore 12 in the main body 4. The upper end of the clamping screw 11 has a connecting element 13 with which a screwing tool can be positively coupled. At the lower end, the clamping screw 11 has a driver 14. The driver 14 protrudes from the bore 12 and into the first slot 8. The driver 14 engages behind a recess in each of the sides of the clamping jaws 5a, 5b facing each other and designed to be complementary to the driver 14. By screwing the clamping screw 11 into the main body 4 from the top 10, pressure is exerted on the clamping jaws 5a, 5b via the driver 14 and the recess, by which the clamping jaws 5a, 5b are pressed into the release position. As mentioned, the left half of the Fig.4 the clamping jaw 5a and the left half of the clamping screw 11 in this release position. Unscrewing the clamping screw 11 upwards causes both clamping jaws 5a, 5b to be pivoted towards each other into the clamping position. The right clamping jaw 5b and the right half of the clamping screw 11 are in Fig.4 shown in this clamping position.

It should be noted that the clamping means can also be implemented using any other elements. Instead of a clamping screw, for example, a so-called quick-release device can be used, which is known from bicycle construction. In this case, a clamping lever with an eccentric is supported on the top 10 of the main body 4, whereby by turning the eccentric a shaft with a driver is pulled upwards and the clamping jaws are moved into the clamping position.

On the sides facing each other, the clamping jaws 5a, 5b each have a sawtooth profile 15. Due to the sawtooth profile 15, the clamping jaws 5a, 5b have point-shaped contact areas with the surfaces of the support element 3 in the clamping position, whereby a particularly high surface pressure is created in the contact areas and secure fastening of the fastening device 1 to the support element 3 is ensured.

In particular, when the clamping jaws 5a, 5b with the sawtooth profiles 15 press into the material of the support element 3, a high force may be required to release the clamping jaws 5a, 5b from the support element 3 again. To ensure that the clamping screw 11 is not damaged, for example when the clamping jaws 5a, 5b are released, the clamping jaws 5a, 5b can have structures by means of which an additional force can be applied manually to open the clamping jaws 5a, 5b. These structures are designed as projections 16a, 16b on the sides of the clamping jaws 5a, 5b facing away from one another. When the projections 16a, 16b are pressed together (i.e. moved towards one another), the clamping jaws 5a, 5b are pivoted about their respective pivot axis into the release position. By simultaneously pressing the projections together and screwing in the clamping screw 11, the clamping jaws 5a, 5b can be easily released from the support element 3.

To fix the workpiece 2 to the fastening device 1 of the Fig. 1 - 4 a holding element 17 is arranged above the main body 4. In this embodiment, the holding element 17 is flat and has the shape of an annular disk. By means of a clamping means 18, which in the embodiment described here is designed as a clamping screw 18 screwed into a threaded hole 23 in the main body 4, the holding element 17 is slidably attached to the top 10 in a displacement direction running perpendicular to the top 10 of the main body 4. As a result, a second gap 19 is formed in a second plane extending at right angles to the first plane between the holding element 17 and the top 10 of the main body 4. The workpiece 2 can be clamped in the second plane between the top 10 and the holding element 17.

The Fig. 13 shows, as mentioned, a fastening device 1 of the Fig. 1 to 4 , which fixes a workpiece 2. The wear plate 3 extends through the slot 9 and is clamped with the clamping jaws. The workpiece 2 is a flat plate which is clamped against the main body 4 of the fastening device 1 with the disk-shaped holding element 17.

Furthermore, Fig. 13 a spacer element 20 can be seen, the free end surface of which supports the plate-shaped workpiece 2. Embodiments of such spacer elements 20 are described below with reference to the Figs. 7 - 11 explained in more detail.

In the Figures 5 and 6 a second embodiment of the fastening device 1' is shown. With the exception of the features described below, the second embodiment of the fastening device 1' corresponds to the first embodiment described above. In the second embodiment of the fastening device 1', the holding element 17' is larger than the top side 10' of the main body 4' and is essentially rectangular. It protrudes laterally beyond the main body so that a workpiece 2' can be pressed by the holding element 17' against the upwardly facing edge of the support element 3', to which the fastening device 1' is fixed. The holding element 17' is fastened to the top side 10' with two identical clamping screws 18' in a displacement direction running perpendicular to the top side 10' of the main body 4'. The clamping screws 18' are identical to the clamping screw 18 of the first embodiment.

The clamping jaws 5a', 5b' are each mounted so that they can slide around a pivot axis. The clamping jaws 5a', 5b' are moved separately by means of a clamping means designed as a clamping screw 11' that is accessible from the top 10' of the main body 4'. The two clamping screws 11' each extend through a hole 12' with an internal thread in the main body 4' that extends from the top 10' of the main body 4' to the first slot 8'. The clamping screws 11' are essentially designed in the same way as the clamping screw 11, but they do not have a driver, but rather a stump at the lower end. The two stubs of the two clamping screws 11' protrude from the two holes 12' and into the first slot 8'. Each of the two stumps presses on an upward-facing edge of one of the two clamping jaws 5a', 5b'. By screwing the clamping screws 11' into the main body 4' from the top 10', a pressure is exerted on the clamping jaws 5a', 5b' via the stump, by which the clamping jaws 5a', 5b' are pushed into the Fig.6 shown clamping position. Unscrewing the clamping screws 11' upwards means that no more pressure is exerted on the clamping jaw 5a' or 5b' located under the unscrewed clamping screw 11'. Spiral springs (not shown here), one of which is arranged around the pivot axis of the clamping jaws 5a', 5b' and connected to one of the two clamping jaws 5a', 5b', press the clamping jaws apart when the pressure on the clamping jaws 5a', 5b' is removed by unscrewing the clamping screws 11'.

Fig.7 shows a spacer element 20 which is designed as a round piece of pipe with parallel end faces 21a, 21b. A diametrically extending slot 22 is made in the spacer element 20 at right angles to the lower end face 21b, the width of which is matched to the thickness of the support element 3. The spacer element 20 is pushed onto the support element 3 with the slot 22. Consequently, the width of the slot 22 should be a small Undersize in relation to the thickness of the support element 3 so that the slot 22 expands elastically when pushed onto the support element and the spacer element 20 sits firmly on the support element 3. The upper end face 21a forms the free end face of the spacer element 20 on which the workpiece 2 can rest. An unslotted area of the spacer element 20 extends in the axial direction of the spacer element 20 from the free end face 21a to the slot 22. As in Fig. 13 As can be seen, the length of the unslotted area of the spacer element 20 is identical to the distance between the upper edge of the support element 3 and the top side 10 of the main body 4 of the fastening device 1, to which the fastening device 1 is attached. The upper edges of the support elements 3 of a water jet cutting system are generally in one plane. Thus, a common plane can be spanned by the top side 10 of the fastening device 1 and the free end surface 21a of the spacer element 20, which forms the support plane for the flat underside of the workpiece 2.

In practice, several spacer elements 20 and/or fastening devices 1 can also span a common plane, as in the Figures 18 and 19 In this case, the length of the unslotted areas of all spacer elements 20 is identical and corresponds to the distance between the top 10 of all fastening devices 1 and the bottom of the workpiece 2.

The distance between adjacent spacer elements 20 is to be selected so that the workpiece 2 does not bend excessively between these spacer elements 20. The distribution of the spacer elements 20 over the surface of the workpiece can, as in Fig. 18 shown, may be irregular. In Fig. 18 and 19 a plate-shaped workpiece 2 with a square surface is fastened at all four corners by means of a fastening device 1. The number of fastening devices 1 can also be reduced or increased in order to securely fix the workpiece 2. When machining with water jets impinging perpendicularly to the surface of the workpiece 2, hardly any transverse forces act on the workpiece 2 and the required holding force of the fastening devices 1 is quite low, so that fewer than four fastening devices 1 can be sufficient.

The spacer elements 20 can also be distributed irregularly over the surface of the workpiece 2. It is possible to project the cutting pattern that is to be produced by the water jet onto the work table using a projection device, in particular using a laser. In the case of a workpiece made of natural material, for example a wooden board or a stone board, grain and color patterns can be aligned with respect to the cutting line to be produced. It is also possible to distribute the spacer elements 20 at least to distribute them mostly over the surface of the workpiece 2 in such a way that they are not cut by the water jet. In this way, at least the majority of the spacer elements 20 can be used multiple times.

The Figures 7 , 13 , 14 and 16 The spacer elements 20 shown have the shape of a tube with a circular cross-section. The shapes of the spacer elements can, however, deviate from the circular shape. For example, rectangular tubes or other tube shapes can be used whose end surfaces extend at right angles to their axis of symmetry and which have a slot in a plane which preferably contains the axis of symmetry. Other shapes of the spacer elements, each of which is attached to a support element, are shown in the Figures 8 - 12 shown.

The Figures 8 - 12 show strip-shaped spacer elements. The spacer element 20a of the Fig.8 has a cross-section that resembles the gable side of a house. In axial plan view, this cross-section is made up of a rectangular basic shape and a roof section placed on top of it with roof surfaces arranged symmetrically to the center line of the rectangle. The slot 22 is arranged in the middle of the lower base line of the rectangular basic shape and extends upwards along the vertical axis of symmetry of the cross-section approximately to the middle of the height of the spacer element. The ridge line of the roof section of the strip-shaped spacer element 20a forms the free end surface or front surface 21a on which the workpiece rests.

The spacer element 20b of the Fig.9 has a circular cross-section, with the slot 22 extending radially to the middle of the cross-section. The outer surface of the strip-shaped spacer element 20a opposite the opening of the slot 22 forms the free end face 21a on which the workpiece rests. The same applies to the spacer element 20c of the Fig.10 , which does not have a solid cross-section, but a cylinder shell with radial webs, which is manufactured as an extruded profile.

The Fig. 11 shows again a strip as spacer element 20d with the same profile as the strip 20a in Fig.8 . Here, longitudinal cavities are provided, which save material and weight. The spacer element 20d is made as an extruded profile. The spacer element 20e of the Fig. 12 is an extruded profile. The profile cross-section essentially corresponds to that of the spacer element 20d from Fig. 11 , wherein the free end face 21a is enlarged by a horizontally extending web.

As mentioned above, the Fig. 13 a combination of the fastening device from the Fig.1 with a spacer element 20 from the Fig.7 . The fastening device can be combined in a similar way with the other spacer elements 20a - 20e.

In the case of a Fig. 14 to 17 In the embodiment of the fastening device 1 shown, the main body 4, the clamping jaws 5a, 5b and the clamping screw 11 are essentially designed as described above. Only the top 10 of the main body and the holding element 17 are designed differently. The top 10 of the main body 4 has a guide surface 24 that is beveled relative to the horizontal underside of the holding element 17 and the holding element 17 is designed as a spring clamp. The spring clamp 17 presses the workpiece 2 in the direction of the top 10 when it is pivoted into the horizontal position, as in Fig.10 shown. The spring clamp 17 thus also forms the clamping element. In this embodiment, the screw 18 only fixes the spring clamp 17 to the main body 4.

The top side 10 of the main body 4 extends from the right edge of the main body 4 facing the viewer to its center. The horizontal top side 10 is followed by the beveled guide surface 24. It is inclined towards the bottom of the fastening device 1 so that the workpiece 2 can be pushed laterally into the gap between the beveled guide surface 24 and the spring clamp 17, as shown in Fig.10 shown. When the workpiece 2 is swung down into the horizontal position, it presses the spring clamp 17 upwards from below. The spring clamp 17 deforms elastically. The workpiece 2 is thus held securely and is easy to use. The spring clamp 17 has - like the holding elements 17 of the previously described embodiment - an opening 25 so that a user of the fastening device 1 can bring a screw tool into engagement with the connecting element 13 of the clamping screw 11 under the spring clamp 17.

It should be noted that the shape of the holding element and the clamping device can be varied and adapted to the respective machining process and the shape of the workpiece.

1. 1. Verfahren zur Bearbeitung eines flächigen Werkstücks 2 auf einer Wasserstrahlschneidanlange mit einem Werktisch, der eine Mehrzahl flacher, aufrechter Auflageelemente 3 aufweist, die im Abstand zueinander angeordnet sind, wobei das Werkstück 2 auf eine Mehrzahl von Distanzelementen 20, 20a-20e aufgelegt wird, die über die Fläche des Werkstücks 2 verteilt werden und einen unteren geschlitzten Bereich aufweisen, in dessen Schlitz 22 ein Auflageelement 3 eingesteckt ist, und einen zweiten ungeschlitzten Bereich aufweisen, auf dessen freier Endfläche 21a das Werkstück aufliegt.
2. 2. Verfahren nach Klausel 1, wobei die Länge die ungeschlitzten Bereiche aller Distanzelemente 20, 20a-20e gleich ist.
3. 3. Verfahren nach Klausel 1 oder 2, wobei rohrförmige Distanzelemente 20 verwendet werden.
4. 4. Verfahren nach einem der vorangehenden Klauseln, wobei Distanzelemente 20, 20a-20e aus Kunststoff verwendet werden.
5. 5. Verfahren nach einem der vorangehenden Klauseln, wobei das Werkstück 2 mit mindestens einer Befestigungsvorrichtung 1 fixiert wird, die auf einem Auflageelement 3 festgeklemmt wird.
6. 6. Distanzelement 20, 20a-20e zur Verwendung gemäß einem Verfahren der vorangehenden Klauseln, wobei es einen geschlitzten und einen ungeschlitzten Abschnitt aufweist.
7. 7. Distanzelement 20, 20a-20e nach Klausel 6, das mindestens eines der folgenden Merkmale aufweist:
   • es ist rohrförmig;
   • es ist leistenförmig;
   • der ungeschlitzte Abschnitt erstreckt sich über eine vorgegebene Länge;
   • es besteht aus Kunststoff.
8. 8. Satz zur Befestigung eines flächigen Werkstücks 2 an einem Werktisch, der eine Mehrzahl flacher, aufrechter Auflageelemente 3 aufweist, gekennzeichnet durch eine Mehrzahl von Distanzelementen 20, 20a-20e gemäß den Klauseln 6 und 7.
9. 9. Satz nach Klausel 8, wobei mindestens ein Befestigungselement 1 zum Fixieren eines Werkstücks 2 an einem flachen, aufrechten Auflageelement 3 vorgesehen ist, mit einem Hauptkörper 4, an dem zwei Klemmbacken 5a, 5b zueinander beweglich befestigt sind, welche sich unterhalb des Hauptkörpers 4 erstrecken und mittels eines von der Oberseite 10 des Hauptkörpers 4 zugänglichen Klemmmittels 11 aufeinander zu bewegbar sind, und mit einem Halteelement 17, welches oberhalb des Hauptkörpers 4 angeordnet ist und mittels eines Spannmittels 18 zum Hauptkörper 4 hin bewegbar ist.

With regard to the machining process described above and the spacer elements used, characteristics are summarised in the following clauses:

1. 1. Method for machining a flat workpiece 2 on a water jet cutting system with a work table which has a plurality of flat, upright Support elements 3 which are arranged at a distance from one another, wherein the workpiece 2 is placed on a plurality of spacer elements 20, 20a-20e which are distributed over the surface of the workpiece 2 and have a lower slotted region, into the slot 22 of which a support element 3 is inserted, and a second unslotted region, on the free end surface 21a of which the workpiece rests.
2. 2. Method according to clause 1, wherein the length of the unslotted areas of all spacer elements 20, 20a-20e is the same.
3. 3. Method according to clause 1 or 2, wherein tubular spacer elements 20 are used.
4. 4. Method according to one of the preceding clauses, wherein spacer elements 20, 20a-20e made of plastic are used.
5. 5. Method according to one of the preceding clauses, wherein the workpiece 2 is fixed with at least one fastening device 1 which is clamped onto a support element 3.
6. 6. Spacer element 20, 20a-20e for use according to a method of the preceding clauses, wherein it has a slotted and an unslotted portion.
7. 7. Spacer element 20, 20a-20e according to clause 6, which has at least one of the following features:
   • it is tubular;
   • it is strip-shaped;
   • the unslotted section extends over a predetermined length;
   • it is made of plastic.
8. 8. Kit for fastening a flat workpiece 2 to a work table having a plurality of flat, upright support elements 3, characterized by a plurality of spacer elements 20, 20a-20e according to clauses 6 and 7.
9. 9. Set according to clause 8, wherein at least one fastening element 1 is provided for fixing a workpiece 2 to a flat, upright support element 3, with a main body 4, to which two clamping jaws 5a, 5b are fastened so as to be movable relative to one another, which extend below the main body 4 and can be moved towards one another by means of a clamping means 11 accessible from the upper side 10 of the main body 4, and with a Holding element 17, which is arranged above the main body 4 and is movable towards the main body 4 by means of a clamping means 18.

The features of the invention disclosed in the present description, in the drawings and in the claims can be essential for the realization of the invention in its various embodiments both individually and in any combination. The invention is not limited to the embodiments described. It can be varied within the scope of the claims and taking into account the knowledge of the competent person skilled in the art.

List of reference symbols

1

Fastening device

2

workpiece

3

Support element, wear plate

4

Main body

5a, 5b

Clamping jaws

6a, 6b

bearings

7

Gap in first level

8th

Recess, first slot

9

second slot

10

Top

11

Clamping device, clamping screw

12

drilling

13

Connecting element

14

Driver

15

Sawtooth profile

16

Projections

17

Holding element

18

Clamping device, clamping screw

19

second gap in second level

20

Spacer element

21a, 21b

Front surfaces

22

slot

23

threaded hole

24

Guide surface

Claims (10)

Fastening device (1) for fixing a workpiece (2) to a flat, upright support element (3), with a main body (4) to which two clamping jaws (5a, 5b) are fastened so as to be movable relative to one another, which extend below the main body (4) and can be moved towards one another by means of a clamping means (11) accessible from the top (10) of the main body (4), characterized by a holding element (17) which is arranged above the main body (4) and can be moved towards the main body (4) by means of a clamping means (18). Fastening device (1) according to claim 1, characterized in that a gap (7) is formed in a first plane between the clamping jaws (5a, 5b) and a gap (19) is formed in a second plane between the holding element (17) and the upper side (10) of the main body (4), wherein the second plane is perpendicular to the first plane. Fastening device according to claim 1 or 2, characterized in that the clamping means (11) is a clamping screw (11). Fastening device according to one of the preceding claims, characterized in that the clamping jaws (5a, 5b) are pivotally attached to the main body (4). Fastening device according to one of the preceding claims, characterized in that the main body (4) has a recess (8) in which the clamping jaws (5a, 5b) are arranged. Fastening device according to one of the preceding claims, characterized in that the clamping jaws (5a, 5b) have a sawtooth profile (15) on their mutually facing sides. Fastening device according to one of the preceding claims, characterized in that the holding element (17) is fastened to the upper side (10) of the main body (4) so as to be displaceable in a displacement direction which runs perpendicular to the upper side (10). Fastening device according to claim 5, characterized in that the holding element (17) is fastened to the main body (4) by means of an elastic tensioning means, which the holding element (17) is pushed towards the upper side (10) of the main body (4), the main body (4) having an inclined guide surface opposite the underside of the holding element (17), which defines with the underside of the holding element an insertion gap running obliquely to the direction of displacement. Fastening device according to one of the preceding claims, characterized in that the clamping jaws (5a, 5b) each have a projection (16a, 16b) on the sides facing away from each other. Set for fixing a workpiece (2) to a work table with a flat, upright support element (3), comprising at least one fastening device (1) according to one of claims 1 to 9 and a plurality of spacer elements (20) with a slotted and an unslotted region.

Images