FILE FOR CREATING AN UNEVEN CONTOUR, ESPECIALLY WITH A TRANSVERSE CURVE

Description

[0001] The invention relates to a file for producing an uneven contour, in particular with a transverse curvature on a workpiece, according to the preamble of claim 1. An example of such a file is known from US 2014 / 199919 A1.

[0002] In the manufacture of a stringed instrument, especially a plucked instrument with a fingerboard, frets are attached to the fingerboard at specific intervals, decreasing evenly towards the bridge, depending on the scale length. These frets are used to determine specific pitches when playing a plucked instrument by pressing down on the strings. The scale length is defined as the length of a freely vibrating string between a nut at the top of the fingerboard and a saddle in the bridge on the soundboard of the instrument. The distance from the nut to the first fret is calculated by dividing the scale length by 17.817. This distance is then subtracted from the scale length, and the result is divided again by the same divisor of 17.817. This gives the distance from the first fret to the second fret. The other distances can be calculated accordingly. The frets are rod-shaped and are attached to the fingerboard.At certain points, the frets are countersunk into the fretboard down to their transversely curved sections and then leveled to ensure they protrude evenly along the fretboard. This leveling process alters the originally rounded outer contours of the frets. Restoring these rounded contours while maintaining the fret heights achieved during the leveling process is a complex and time-consuming task, but absolutely necessary to prevent unwanted buzzing and to preserve the pitches defined by the fret centers, which run perpendicular to the fretboard. Any reduction in fret height below the levels achieved during the leveling process must be avoided.

[0003] US 2014 / 199919 A1 and US 2013 / 0 125 731 A1 disclose files for machining fret bars.

[0004] US 2020 / 0 282 519 A1 discloses a file tool for machining frets of a stringed instrument.

[0005] US patent 5,895,316 discloses a grinding device. US patent 1,742,070 discloses a polishing device.

[0006] The invention is based on the objective of simplifying the production of an uneven contour, in particular with a transverse curvature, on a workpiece, in particular a bar-like workpiece, while maintaining a height level already produced on the workpiece.

[0007] This problem is solved by a file with the features mentioned in claim 1. It is known that the file has at least one file element with an abrasive machining surface and a depth stop element with a non-abrasive sliding surface.

[0008] The non-abrasive sliding surface provided in the file according to the invention ensures that unwanted material removal in this area is prevented during machining of the workpiece. The non-abrasive area of ​​the file serves as a depth stop.

[0009] This prevents the fret height produced by a dressing process from being unintentionally reduced when the fret is anchored in a fingerboard. However, due to the at least one abrasive file element, it is possible to machine the remaining contour of the fret. Such a fret forms a workpiece that can be machined with the file. The fret initially has a rounded outer contour, which is affected, particularly flattened, as a result of dressing. The file according to the invention makes it possible to produce an uneven contour, particularly with a rounding and / or a transverse curvature. In particular, the achievable contour of the workpiece can be variably defined depending on the contour of the machining surface. In a plane perpendicular to the longitudinal axis of the workpiece, the contour is in particular a spline of the nth degree, and in particular a spline of the 4th degree.

[0010] The workpiece to be machined may originally have a polygonal outer contour, in particular a triangular cross-section.

[0011] The file can also comprise several, in particular at least two and in particular exactly two, file elements. The file can also comprise several depth stop elements. Several file elements and / or several depth stop elements can be combined with each other to form the file with a depth stop function.

[0012] The at least one file element and the at least one depth stop element are detachably connected. This facilitates the replacement of the at least one file element and / or the at least one depth stop element. Alternatively, the at least one file element and the at least one depth stop element can be permanently connected. Permanently connected means that the elements can only be separated by destructive means. With a permanent connection, the file is particularly robust.

[0013] The at least one file element is made of a tool material, in particular steel, and especially tool steel. Other tool materials are also possible, in particular aluminum alloys. The abrasive machining surface is provided with a diamond coating and / or sapphire coating. However, the abrasive machining surface can also be provided with other types of coating and additionally or alternatively have a surface texture, in particular with regularly or irregularly arranged protrusions and depressions. In particular, the abrasive machining surface is milled, and in particular hand-milled.

[0014] The at least one depth stop element is made in particular of a high-strength material, in particular of a high-strength, machinable high-performance and / or engineering plastic, such as in particular polyetheretherketone (PEEK), polyphenylene sulfide (PPS) or polyimide (PI).

[0015] The non-abrasive sliding surface is characterized by being free of abrasive coatings and being formed by a base material of the depth stop element. The base material of the depth stop element may be a layered material such as TiAlN. The non-abrasive machining surface is smooth. The sliding surface may be ground and / or polished. The sliding surface has an arithmetic mean roughness Ra of at most 0.4 µm, in particular at most 0.2 µm, in particular at most 0.1 µm, in particular at most 0.05 µm, and in particular at most 0.025 µm.

[0016] The two outer file elements are identical in design and arranged in a mirror-symmetrical manner with respect to a central plane that defines the longitudinal axis of the file body. This simplifies the manufacture of the file, as only two different file elements are required to produce the file body.

[0017] Because the at least one file element and the depth stop element are arranged side by side in a plane oriented perpendicular to the longitudinal axis, the machining of the flange bars is simplified. The file can be placed directly onto the flange bar with the at least one file element, and the flange bar can thus be machined. The depth stop element prevents unintentional machining of the flange bar in the depth direction by resting either directly against the flange bar being machined or against a laterally adjacent flange bar. In particular, the at least one file element and the depth stop element are oriented essentially parallel to each other along the longitudinal axis.The at least one file element and the depth stop element are arranged at a distance, in particular at a distance oriented perpendicular to the longitudinal axis, from each other in the plane oriented perpendicular to the longitudinal axis.

[0018] The file, in which the depth stop element forms a file body with at least one recess for inserting the at least one file element, enables advantageous repair of individual flange bars, which can be rounded while maintaining their level, without requiring all, especially adjacent, flange bars to be dressed beforehand. It was recognized that it is advantageous if the sliding surface of the depth stop element can be located outside the flange bar being worked and, in particular, in the area of ​​adjacent flange bars. This simplifies the design and construction of the file and reduces manufacturing costs. The depth stop element forms a file body with at least one recess into which the at least one file element is inserted. Specifically, the at least one file element is recessed into an underside of the file body.At least one file element is designed as a hollow file.

[0019] The file body is manufactured with particular precision, especially fine milling, especially grinding, especially polishing, with a flat, sliding underside that forms the sliding surface. The sliding surface is also called the sliding area. In a plane defined by the local cross-sectional maxima of the individual frets, the file body extends along a file body length that is particularly greater than the sum of the two distances between two adjacent frets on the fingerboard. In particular, the file body is dimensioned such that at the beginning of machining, it initially rests on at least one or more frets located adjacent to the fret being machined. At the beginning of the machining process, the sliding surface, especially in the case of a non-spring-mounted file element, will initially rest exclusively on the fret that can just be reached by the sliding surface.Because the sliding surface rests on at least two adjacent flanged bars during the machining of the flanged bar, and especially towards the end of the machining process, and is moved in a sliding manner in the working direction, unwanted material removal is reliably prevented.

[0020] It is particularly conceivable that two file elements are arranged on the file body. These file elements can have essentially identical geometry but different grit sizes. Such a file simplifies the machining of the workpiece by, for example, first roughing with the coarser grit file element and then finishing with the finer grit file element. It is also conceivable to provide two file elements with identical grit sizes, so that the file can still be used even if one of the two file elements is worn, damaged, and / or destroyed.

[0021] The file according to the invention, in which the at least one file element is mechanically pre-tensioned in the depth direction, in particular by means of a compression spring, is arranged on the file body, enables uncomplicated automated compensation of manufacturing tolerances that may occur in particular in the file element, especially if the file element is provided with a diamond coating.

[0022] The file according to the invention, in which the at least one file element is adjustable in the depth direction in addition to or as an alternative to mechanical preload, in particular by means of a movement thread, in particular by means of a movement fine thread, is arranged on the file body, enables the targeted positioning of the at least one file element relative to the file body by fine adjustment.

[0023] A file according to claim 2 ensures a stable construction of the file body. The manufacturing and production of the file is simplified. The at least one file element and the depth stop element can be manufactured independently of one another, and in particular, the working surface can be designed independently. After its manufacture, the at least one file element is connected to another file element and / or to the depth stop element, in particular by a fixed connection. The connection can be detachable, in particular by screws or clamps. The connection can also be permanent, for example by gluing, soldering, or welding. Adhesive bonding is achieved in particular by means of a two-component epoxy resin-based structural adhesive.

[0024] In particular, the connection between the file elements can be improved, especially additionally, by positive locking, for example by sliding the file elements onto each other according to a tongue-and-groove principle along the longitudinal axis of the file or at an angle of inclination with respect to the longitudinal axis.

[0025] A file according to claim 3 simplifies the creation of the transverse curvature on the workpiece. The abrasive machining surface is, in particular, substantially concave throughout and exhibits a continuous curvature, especially a constant curvature. This allows for symmetrical self-adjustment of the file during filing movements to restore the transverse curvature and, in particular, to create a rounded surface. The perpendicular through the local maximum of the original rounded surface onto the fingerboard and the perpendicular through the center of the flattened workpiece onto the fingerboard tend to coincide. It is advantageous if the radius of curvature of the abrasive machining surface is larger than the original radius of curvature of the workpiece.

[0026] In particular, the curvature of the abrasive machining surface is designed as a circular segment and has an opening angle to the center point of at least 30°, in particular at least 35°, in particular at least 40°, in particular at least 45°, in particular at least 50° and in particular at least 60° and in particular at most 85°.

[0027] It is additionally or alternatively possible for the concave, abrasive machining surface to be executed without continuous curvature. It has proven advantageous if at least one of the following criteria is met for the concave contour, and in particular if all of the following criteria are met. A first criterion concerns the lateral distance between the two axially extending edge regions of the machining surface. This distance must be greater than the width of the collar bar. A second criterion concerns the symmetry of the concave contour. The contour has the properties of a straight real function. This means that the concave contour is mirror-symmetric with respect to a plane of symmetry, where the plane of symmetry is oriented perpendicular to the width direction of the collar bar and encompasses the longitudinal axis of the file. The production of the collar bar with improved collar purity is possible.In a central area of ​​the concave contour, it can be relatively sharp. A third criterion concerns the position of the fret's local maximum. After the fret has been completely rounded, its local maximum must be located closer to the axially extending edge regions of the file elements than to the surface of the fret. This means that the distance in the depth direction from the fret's maximum to the underside of the file element is smaller than the distance in the depth direction from the fret's local maximum to the surface of the fingerboard.

[0028] The machining surface is, in particular, at least partially concave. For example, the contour can also be partially convex, especially in the form of a bell curve. A bell curve has, in particular, several, especially two, inflection points. It is advantageous if the concave profile is laterally bounded by parallel edge regions without sharp-edged, i.e., discontinuous, steps.

[0029] Additionally or alternatively, the machining surface can also be convex, essentially forming a V-shaped recess with a rounded base. Creating such a recess is straightforward.

[0030] A file according to claim 4 is robustly designed and advantageously, namely in a simplified manner, manufacturable.

[0031] A file according to claim 5 is advantageous in handling, robust in design and enables uncomplicated manufacture of the file body.

[0032] A file according to claim 6 ensures reliable attachment of the file element to the file body. A retaining element enables the file element to be held by positive locking and / or frictional locking. In particular, the retaining element is designed as a screw, especially as a clamping screw, particularly in the form of a ball-head screw, as a through-bolt, or as a motion screw, especially with a motion thread.

[0033] A file according to claim 7 enables reliable retention of the at least one file element. It is advantageous if the at least one file element has several, in particular exactly two, retaining grooves. This results in particular advantages with regard to the fine adjustment of the file elements on the file body.

[0034] A file according to claim 8 prevents the unintentional loss of the at least one file element and in particular ensures reliable clamping of the at least one file element by means of the holding element.

[0035] A file according to claim 9 enables axial fixation of the file element by means of the holding element.

[0036] A file according to claim 10 enables advantageous workpiece machining. An arrangement of the at least one file element relative to the file body such that a low point of the machining surface is set back in the depth direction relative to a plane defined by the sliding surface advantageously ensures that a material protrusion remains on the collar bar to be machined after machining. The setback arrangement is therefore particularly suitable for a file in which the at least one file element has a comparatively large surface roughness, i.e., for rough machining. Accordingly, an arrangement of the low point in the plane of the sliding surface is advantageous for a file with a fine or small surface roughness, which is to be used particularly for finishing, especially final machining or fine machining.This allows the collar bar to be machined with the finishing file along its entire length, in particular its entire length, so that its local cross-sectional maximum is arranged in the plane determined by the sliding surface.

[0037] The manufacture of a file element according to claim 13 is particularly cost-efficient. It has been found that the various functions fulfilled by the file element can be separated. The holding function of the file element is fulfilled, in particular, by a file retainer element. The file retainer element can advantageously be held and attached to the file body. In particular, the file retainer element is designed with appropriate features for holding and / or attaching it to the file body. It has been found, in particular, that it is not necessary for the file retainer element to be made of a material with an abrasive surface, such as a diamond coating. The file retainer element can be made of a comparatively cost-effective and / or a comparatively machinable material.

[0038] In particular, a file insert is held and / or attached to the file holder. The file insert has the abrasive surface used for workpiece machining. Since the file insert is held by the file holder, special design features on the file insert are unnecessary. The file insert can be designed with a relatively simple geometry and is therefore cost-effective to manufacture. A special material, particularly one with a diamond coating, can be used for the file insert.

[0039] A file g, in which the at least one file element forms a file body to which the depth stop element is attached, in particular inserted into a recess, wherein in particular the non-abrasive sliding surface is at least partially convex and in particular has an extremum, in particular a local extremum, in particular a maximum, wherein in particular the extremum has a depth distance that is oriented perpendicular to a virtual connecting line that is defined by mutually facing contour endpoints of the abrasive machining surface, and / or wherein in particular the contour of the non-abrasive sliding surface has a width oriented perpendicular to the longitudinal axis that is at most 0.3 mm, in particular at most 0.2 mm, in particular at most 0.15 mm and in particular between 0.01 mm and 0.1 mm, enables a reliable depth stop function.Because the contour of the non-abrasive machining surface is at least partially convex, a projection is formed on the central file element, which protrudes, in particular, from the abrasive machining surfaces. The contour of the machining surface in the non-abrasive area therefore exhibits, in particular, a local extremum, specifically a local maximum.

[0040] In particular, the outer file elements are arranged on the file body in such a way that the two curves have a common center of curvature, i.e., form a common curvature which is interrupted only by the depth stop element.

[0041] A file in which the extremum has a depth distance oriented perpendicular to a virtual connecting line defined by mutually facing contour endpoints of the abrasive machining surfaces ensures that unintentional material removal is reliably prevented. The depth distance is, in particular, at least 0.02 mm, in particular at least 0.04 mm, and in particular at least 0.05 mm. In particular, the depth distance, relative to a width oriented perpendicular to the longitudinal axis and, in particular, perpendicular to the central plane of the file body, is between half and five times the width.

[0042] A file where the contour of the non-abrasive sliding surface has a width of no more than 0.3 mm oriented perpendicular to the longitudinal axis ensures that unwanted material removal is avoided when the file is tilted relative to the workpiece. The width is specifically between 0.01 mm and 0.1 mm.

[0043] Both the features specified in the claims and those specified in the following description of embodiments of the files according to the invention are suitable, individually or in combination, for further developing the subject matter of the invention. The respective combinations of features do not represent any limitations with regard to further developments of the subject matter of the invention, but are essentially merely exemplary.

[0044] Additional features, advantageous embodiments, and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawings. The drawings show: Fig. 1 shows a cross-section through a non-inventive file in a plane perpendicular to a longitudinal axis of a file body, Fig. 2 shows an enlarged detail view of detail II in Fig. 1 Fig. 3 a top view of a file according to the invention, in which the file body forms a depth stop element, Fig. 4 a sectional view along section line IV-IV in Fig. 3 , Fig. 5 a side view of the file in Figs. 3 and 4 , Fig. 6 a side view of a file element of the file in Fig. 3 , Fig. 7 a sectional view according to section line VII-VII in Fig. 6 Fig. 8 shows a bottom view of a file according to a further embodiment, Fig. 9 shows a sectional view along section line IX-IX in Fig. 8Fig. 10 shows a side view of a file according to a further embodiment with a through-bolt; Fig. 11 shows a side view of a file element of the file in Fig. 10 with screw and file element removed, Fig. 12 an enlarged sectional view of a file according to a further embodiment with a screw with a threaded drive, Fig. 13 a Fig. 6 corresponding view of a multi-part file element according to a further embodiment, Fig. 14 a side view of the file element according to Fig. 13 , Fig. 15 a sectional view according to section line XV-XV in Fig. 13 , Fig. 16 Fig. 13 corresponding view of a file element according to a further embodiment, Fig. 17 a sectional view according to section line XVII-XVII in Fig. 16 Fig. 18 a perspective view of a file according to a further embodiment, Fig. 19 a sectional view according to section line XIX-XIX in Fig. 18, Fig. 20 a top view of a file holder receptacle of the file in Fig. 18 , Fig. 21 a sectional view according to section line XXI-XXI in Fig. 20 , Fig. 22 a top view of a file holder guide of the file in Fig. 18 , Fig. 23 an enlarged sectional view of a holding element of the file in Fig. 18 Fig. 24 is a top view of a file holding element of a file according to a further embodiment, Fig. 25 is a sectional view according to section line XXV-XXV in Fig. 24 , Fig. 26 a cross-sectional view of a file insert element of the file in Fig. 24 Fig. 27 is a top view of a length-variable file body of a file according to a further embodiment, Fig. 28 is a sectional view along section line XXVIII-XXVIII in Fig. 27 , Fig. 29 Fig. 27 corresponding sectional view with a surface-variable adjustable file body, Fig. 30 Fig. 27Fig. 31 shows a corresponding sectional view of a file body according to a further embodiment with a variably adjustable compression spring preload; Fig. 32 shows a top view of a file with several file elements according to a further embodiment; Fig. 32 shows a sectional view according to section line XXXII-XXXII in Fig. 31 , Fig. 33 a sectional view according to section line XXXIII-XXXIII in Fig. 31 .

[0045] One in Fig. 1 and 2 The file, shown as a whole with 1, comprises a file body 2 and a file handle attached to the file body 2. The file handle is arranged outside the plane of representation and in Fig. 1 Not shown. File 1 can also be designed without a file handle. In this case, file 1 is gripped directly at the file body 2, which can allow for more precise work.

[0046] The file body 2 has a perpendicular angle to the plane of representation in Fig. 1 oriented longitudinal axis 3 and a median plane 4 containing the longitudinal axis 3.

[0047] The file body 2 is formed by two file elements 5, 6, which are positioned in the drawing plane according to Fig. 1 The file elements 5 and 6 are arranged side by side. They are made of a tool material, in particular a steel material, and in particular a tool steel, or alternatively an aluminum material. The file elements 5 and 6 are firmly connected to one another, for example, by bonding. The respective contact surfaces between the two file elements 5 and 6 serve as the bonding surfaces. The bonding can be applied over a large area and, in particular, over the entire surface. Such an adhesive bond is stable and allows for high positional accuracy of the file elements relative to each other. In particular, two file elements are firmly connected to each other in pairs.

[0048] The file body 2 has a slot-shaped recess between the two file elements 5 and 6. According to the illustrated embodiment, the slot-shaped recess extends over the entire drawing area. It is conceivable that the file elements 5 and 6 have a common contact surface located outside the drawing area. The file elements 5 and 6 can be bonded together at these contact surfaces. Alternatively, it is conceivable that the file body 2 with the slot-shaped recess is manufactured in one piece, i.e., consists of only a single file element into which the slot-shaped recess is machined.

[0049] The file body 2 is designed as a mirror image with respect to the midplane 4. The file body 2 has a profiled shape, with the longitudinal axis 3 corresponding to the longitudinal axis of the profile. The file elements 5 and 6 are, in particular, identical and arranged as mirror images of each other with respect to the midplane 4.

[0050] The two outer file elements 5, 6 have an abrasive machining surface 8, which serves for workpiece machining. According to the illustrated embodiment, the abrasive machining surface 8 is formed by a diamond coating.

[0051] A depth stop element 7 is arranged on the file body 2, particularly in the slot-like recess. The depth stop element 7 is arranged, in particular, between the file elements 5, 6 and, in particular, concentrically with respect to the central plane 4.

[0052] The depth stop element 7 has a non-abrasive sliding surface 9, which is preferably uncoated. The non-abrasive sliding surface 9 is preferably formed by the base material of the depth stop element 7, preferably the steel material and especially the tool steel, and is preferably ground and / or polished.

[0053] The abrasive machining surfaces 8 are each, in particular continuously, concave and have a curvature with a radius of curvature RF. The abrasive machining surfaces 8 each have a circular segment contour with radius RF and extend between points AF to CF and from DF to BF, respectively. The respective opening angle αF with respect to the center point MF of the curvature contour is approximately 45° according to the illustrated embodiment. The center point MF is located in the medial plane 4.

[0054] The contour of the non-abrasive sliding surface 9 is shown in particular in the detailed view according to Fig. 2The contour of the non-abrasive sliding surface 9 is at least partially convex and, in particular, completely convex. The non-abrasive sliding surface 9 is curved and has a smooth transition to the abrasive machining surfaces 8 at points CF and DF. A virtual connecting line 10 is defined by the endpoints CF and DF of the abrasive machining surfaces 8. With respect to the connecting line 10, the non-abrasive sliding surface 9 has a local extremum E, in particular a local maximum, which has a depth distance t relative to the connecting line 10. The depth distance t is oriented perpendicular to the connecting line 10. If the local extremum E coincides with a local maximum of the spline spanned by the file elements 5, 6, small gaps can form parallel to the longitudinal axis 3 of the file 1.Even with these gaps, a kink-free transition between the abrasive machining surfaces 8 and the non-abrasive sliding surface 9 is provided in accordance with the application.

[0055] The maximum E is located in the center plane 4. In particular, the contour of the non-abrasive sliding surface 9 is mirror-symmetrical to the center plane 4. The maximum E projects from the machining surface, especially relative to the abrasive machining surfaces 8. The maximum E serves as a depth stop for the file 1, i.e., as the contact line of the file 1 on a workpiece.

[0056] The depth stop element 7 and thus the non-abrasive sliding surface 9 have a width B oriented perpendicular to the longitudinal axis 3 and in particular perpendicular to the median plane 4, which is in particular at most 0.3 mm and in particular between 0.01 mm and 0.1 mm.

[0057] In Fig. 1Below the file 1, a workpiece 11 is shown, which is arranged as a fret on the fingering area of ​​a stringed instrument, in particular a plucked instrument 12. The fingering area of ​​the plucked instrument 12 comprises a fingerboard 13. The fret 11 has a curved contour with a radius of curvature RW relative to a center point MW. The center point MW is located in the medial plane 4. The radius of curvature RW of the fret 11 is smaller than the radius of curvature RF of the abrasive machining surfaces 8. When the fret 11 is anchored in the fingerboard 13, the original curved outer contour of the fret 11 has been flattened. The flattened contour of the collar bar 11 results along the contour points AW to CW with the curvature RW, from CW to DW with a flattened course, and from DW again with the curvature RW to the endpoint BW .

[0058] The width of the collar bar 11, oriented perpendicular to the center plane 4, between the contour endpoints AW and BW corresponds to the width of the file body 2 between the contour endpoints AF and BF.

[0059] By flattening the flange 11 between points CW and DW, the original workpiece height W0 was reduced to the flattened workpiece height W1. The flattened workpiece contour can be rounded using file 1 by abrasively removing the flanks 14 of the flange 11 with file 1. The flanks 14 are the material areas of the flange 11 that protrude beyond the machining surface 8 and the sliding surface 9. Fig. 1The flanks 14 are formed by the contour starting from the intersection points S1 and S2, respectively, and the contour endpoints CW and DW. The flanks 14 are successively removed over the entire length of the collar bar 11, whereby the width of the segment CW, DW is reduced to the width B. In this area, the file 1 rests on the collar bar 11 at its maximum E, thus preventing unwanted material removal. By tilting the file 1 about the bearing edge 15 at maximum E, i.e., by rotating the file 1 at the bearing edge 15 according to Fig. 1 , 2 By turning clockwise or counterclockwise, the remaining residual fret bar CW , DW can be finally rounded off.

[0060] The following refers to Figs. 3 to 7Another embodiment is described. Structurally identical parts receive the same reference numerals as in the first embodiment, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing "a".

[0061] A key difference compared to the first embodiment is that in file 1a, the file body 2a is formed by the depth stop element 7a. The file body 2a is essentially cuboid and has a length L, a width B, and a height H. According to the illustrated embodiment, the width B is less than the length L. It is advantageous if the width B is determined based on the length of the collar bars to be processed. It is possible to select the width B between 10% and 300% of the collar bar length, particularly between 30% and 200%, and especially between 50% and 100%. The height H extends along a depth direction 16, which is oriented perpendicular to the width B and perpendicular to the length L of the file body 2a.

[0062] The file elements 5a, 6a are arranged on the file body 2a such that the longitudinal axis 3 of the file elements 5a, 6a each extends along the width B of the file body 2a. Along the length L of the file body 2a, the file elements 5a, 6a are arranged side by side. In particular, the file elements 5a, 6a have a file element length along their longitudinal axis 3 that is identical to the width B of the file body 2a.

[0063] The file body 2a has a top surface 17 and a bottom surface 18, which define the height H of the file body 2a. The top surface 17 is in Fig. 4 arranged at the top. The underside 18 is in Fig. 4 The file body 2a is arranged below. It is point-symmetrical with respect to its center of gravity G. By a 180° rotation of the file body 2a according to... Fig. 4Around the center of gravity, the top surface 17 and the bottom surface 18 are interchanged. The file body 2a has recesses 19, each extending from the top surface 17 or the bottom surface 18 along the depth direction 16. The recess 19 is not continuous along the depth direction 16 and extends over approximately 50% of the height H of the file body 2a. Along the width B, the recess 19 is continuous.

[0064] The upper surface 17 and the lower surface 18 are essentially identical and, in the longitudinal direction L, feature two outer non-abrasive sliding surfaces 9 and an abrasive machining surface 8 located between them. When machining a collar bar with the respective file element 5a, 6a, the file 1a can be placed with the sliding surfaces 9 against adjacent collar bars that are not being machined. The sliding surfaces 9 prevent material removal from the adjacent collar bars. The file body 2a functions as the depth stop element 7a.

[0065] In the depth direction 16, a spring receptacle 20 adjoins the recess 19. Along the width direction, several spring receptacles 20, in particular two and in particular at least three spring receptacles 20, can be arranged below the recess 19. The spring receptacles 20 are each designed as a cylindrical blind bore. In particular, the spring receptacles 20 are not continuous in the depth direction 16.

[0066] Each spring receptacle 20 contains a spring element 21, which is axially supported at the base of the spring receptacle in the depth direction 16. According to the illustrated embodiment, the spring element 21 is designed as a mechanical spring, in particular as a helical compression spring. The mechanical spring can also be a leaf spring. Other configurations of the spring element are also possible, such as an air spring.

[0067] The compression spring 21 is dimensioned such that, in the unloaded state, it protrudes from the spring receptacle 20 and extends into the recess 19.

[0068] A file element 5a, 6a is inserted in the recess 19. Each file element 5a, 6a, with its abrasive working surface 8, which is in particular designed as a hollow file with a concave contour, is arranged on the file body 2a such that the concave contour projects from the top surface 17 or the bottom surface 18, respectively. The concave contour has a local minimum M. It is particularly advantageous if the local minimum M is set back from the top surface 17 or the bottom surface 18 in the depth direction 16.

[0069] On one of the bottom sides opposite the concave contour, the respective file element 5a, 6a is supported on the compression springs 21.

[0070] The file elements 5a, 6a have lateral retaining grooves 22, which are spaced apart from each other along the width direction. The retaining grooves 22 serve to hold and / or adjust the file elements 5a, 6a on the file body 2a. The retaining grooves 22 are also referred to as adjustment grooves. According to the illustrated embodiment, one adjustment groove 22 has a V-shaped groove profile and the other adjustment groove 22 has a rectangular groove profile. The adjustment groove 22 extends along an inclined groove direction 23, which is inclined at an angle α to the depth direction 16. The adjustment groove 22 has a variable groove depth TN in the depth direction 16, with a maximum groove depth TN,max being formed on a surface facing the abrasive machining surface 8.

[0071] To hold and fine-adjust the respective file element 5a, 6a in the associated recess 19, particularly along the depth direction and especially against the spring force of the compression spring 21, several, in particular two, holding elements 24 are provided for each file element 5a or 6a. The holding elements are designed as fine-adjustment screws 24, which in particular have a thread and in particular a fine thread. The fine-adjustment screws serve in particular for adjusting, in particular for fine-tuning, the file elements 5a, 6a against the spring force exerted by the spring element 21. The fine-adjustment screws 24 serve in particular for positioning and in particular for fine-positioning the local minimum M on the concave contour of the respective file element 5a, 6a with respect to the depth direction 16. According to the illustrated embodiment, the fine-adjustment screws 24 are designed as ball-head screws in a set screw configuration.On the two opposite end faces, extending along height H and width B, transverse bores with internal threads are arranged, each opening into the recess 19. The set screws are screwed into the transverse bore until their ball heads engage in the respective adjustment groove 22. Because at least one adjustment groove 22 is V-shaped, the respective file element 5a, 6a is positioned and thus fixed axially in the width direction and / or along the depth direction 16. Because the other adjustment groove 22 is rectangular or U-shaped, the file elements 5a, 6a have a certain amount of play in the longitudinal direction of the longitudinal axis 3, thus allowing for a tolerance should the respective file element 5a, 6a unintentionally tilt within a small angular range, which is in particular less than 2°, in particular less than 1°, and in particular less than 0.5°, during displacement along the depth direction 16.Such a tilting could be temporarily compensated for by the aforementioned tolerance in the axial direction, so that in particular an undesirable clamping of the file element 5a, 6a on the file body 2a is prevented.

[0072] The fine adjustment screws 24 have an internal hexagon socket opening at their rear end for actuating them. It is also conceivable that the fine adjustment screws 24 are not designed as set screws.

[0073] Additional locking grub screws 25 can be used to secure the fine adjustment screws 24. These screws extend in the width direction and can be screwed in through the respective fine adjustment screw 24, particularly perpendicular to the screw-in direction of the respective fine adjustment screw 24. For this purpose, the respective fine adjustment screw 24 has a through-hole with an internal thread that corresponds to the external thread of the locking grub screw 25.

[0074] The fine adjustment screw 24 enables immediate and direct fine adjustment of the position of the file elements 5a, 6a relative to the file body 2a along the depth direction 16. Such fine adjustment may be necessary in particular due to manufacturing tolerances, especially during the production of the file elements 5a, 6a.

[0075] The concave contour of the machining surface 8 is, in particular, arc-shaped and specifically designed as a partial circle with an arc length smaller than that of a semicircle and a constant radius of curvature RF. Because the arc length is smaller than that of a semicircle, it is ensured that the file element 5a, 6a does not rest on the fingerboard and thus prevent complete machining of the workpiece. The arc length is, in particular, less than 180°, in particular at most 175°, in particular at most 170°, in particular at most 165°, and in particular at most 145°. In particular, the respective file element 5a, 6a is rounded at its end face with the radius of curvature RF towards the side edges in the width direction.

[0076] According to a further embodiment, not shown in the drawing, which is essentially the same as the previous embodiment according to Figs. 3 to 7Accordingly, at least one file element 5a, 6a has a flat machining surface 8. The machining surface 8 is therefore neither concave nor convex. The machining surface 8 is uncurved.

[0077] The at least one file element is arranged on the file body in such a way that the machining surface is flush with the file body. This means that the abrasive machining surface lies in a plane defined by the sliding surface of the file body.

[0078] Such a file can be used, in particular, for repairing a single fret when this single fret is inserted on the fingerboard between other frets, where these other frets have already been rounded. With the file described here, preliminary work is possible using the flat file element, with final work being carried out, in particular, using a file according to the first embodiment in Fig. 1 and 2 This has been done.

[0079] The following refers to Figs. 8 and 9 A third embodiment is described. Structurally identical parts receive the same reference numerals as in the first two embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing "b".

[0080] A key difference compared to the previous embodiment is that the position of the file element 5b is adjusted by means of a fine adjustment screw 26. Specifically, two fine adjustment screws 26 are spaced apart along the width B and serve to fine-tune the file element 5b in the depth direction 16. This prevents the file element 5b from tilting with its longitudinal axis 3 relative to the plane defined by the underside 18. The fine adjustment screw 26 comprises a sleeve-like receptacle 27 with an external thread that can be screwed into a corresponding internal thread of a screw receptacle 28 in the file body 2b. This ensures that the fine adjustment screw is reliably positioned and fixed to the file body 2b.

[0081] A radially projecting collar stop 29 is integrally formed with the sleeve receptacle 27 and protrudes from the upper surface 17 of the file body 2b. The collar stop 29 has an outer diameter larger than the inner diameter of the screw receptacle 28. The sleeve receptacle 27 has a through-hole with an internal fine thread into which a pin 30 of the fine adjustment screw 26 with a corresponding external fine thread can be screwed. The pin 30 has a ball head and can be screwed in along the depth direction 16 until it reaches the stop on the bottom wall of the file element 5b. The fine adjustment screw 26 allows for immediate and direct fine adjustment of the position of the file element 5b relative to the file body 2b along the depth direction 16. Such fine adjustment may be necessary, in particular, due to manufacturing tolerances, especially during the production of the file element 5b.

[0082] The following refers to Figs. 10 and 11 A fourth embodiment is described. Structurally identical parts receive the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing "c".

[0083] A key difference compared to the previous embodiments is that the file element 5c is directly fixed to the file body 2c of the file 1c. This is achieved by the retaining element 24c, which is designed as a through-bolt. The retaining element 24c can be a screw with a metric thread and a socket head, a so-called Allen screw. A corresponding fastening thread 31, designed as a blind hole with an internal thread, is provided on the file body 2c for each retaining element 24c. Specifically, fastening threads 31 spaced apart from each other in the width direction 2 are arranged on the file body 2c.

[0084] A further difference compared to the previous embodiments is that, in the file element 5c, the retaining grooves 22 are located on a side wall facing away from, and in particular opposite, the retaining element 24c. Corresponding projections 32 are formed on the file body 2c, in particular integrally. The retaining grooves 22c and the corresponding projections 32 are each inclined at an angle α relative to the depth direction 16. The file element 5c is displaceable along the groove direction 23 relative to the file body 2c.

[0085] In the illustrated embodiment, the file element 5c can also be designed without a retaining groove 22c and corresponding projections 32. The force-fit between the file element 5c and the file body 2c generated by the retaining elements 24c prevents axial displacement of the file element 5c along the longitudinal axis 3.

[0086] To simplify the flexible positioning of the file element 5c on the file body 2c, the through-holes 33 in the file element 5c are designed, particularly in the depth direction 16, with a clear width b that is larger than the outer diameter of the retaining element 24c. It is generally conceivable that the through-hole 33 is circular. According to the illustrated embodiment, the through-hole 33 is essentially elongated with a longitudinal extension in the depth direction 16. The clear width a in the width direction B is, in particular, smaller than the clear width b in the depth direction 16. This allows the file element 5c to be variably fixed in the width direction by the retaining elements 24c. Mounting the file element 5c on the file body 2c is simplified.In particular, the elongated through-holes 33 enable compensation of manufacturing tolerances in the production of the file element 5c and / or the file body 2c. Specifically, the retaining elements 24c are arranged without play in the through-holes 33 in the lateral direction.

[0087] Precise adjustment of the file element is achieved here by means of steel foils (not shown in detail) which are positioned and clamped at suitable points between the surface of the file element 5c opposite the machining surface 8 and the corresponding surface of the file body 2c.

[0088] The following refers to Fig. 12Another embodiment is described. Structurally identical parts receive the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing 'd'.

[0089] A key difference compared to the previous embodiments is that the file element 5d is held directly in the depth direction 16 by the retaining element 24d. The retaining element 24d is arranged as a fastening screw in a recess 34 provided for this purpose on the upper surface 17 and extends along a through-opening in the depth direction 16 to the recess 19d in which the file element 5d is located. On its bottom side opposite the concave machining surface 8, the file element 5d has a receiving bore with an internal thread that corresponds to the external thread of the retaining element 24d.

[0090] Precise adjustment of the file element is achieved using steel foils, analogous to the previous embodiment.

[0091] Several retaining elements 24d can be provided along the width direction. The design of the file 1d and, in particular, the attachment of the file elements 5d to the file body 2d is especially straightforward.

[0092] The following refers to Figs. 13 to 15 Another embodiment is described below. Structurally identical parts receive the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing 'e'.

[0093] A key difference compared to previous embodiments is that the file element 6e is designed in multiple parts. The file element 6e comprises a file holding element 35 and a file insert element 36 held by the file element 35.

[0094] The file holder 35 is essentially designed as an open rectangular hollow strip, and thus, in particular, essentially U-shaped. The file insert 36 is inserted into the file holder 35 and held in the depth direction 16 by means of at least one retaining element 37. According to the illustrated embodiment, several, in particular two, retaining elements 37 are provided. The retaining elements 37 are, in particular, designed as permanent magnets, which are arranged, in particular, in the base of the recess of the file holder 35 and are, in particular, integrated into the file holder 35. In particular, the file insert 36 is made of a ferromagnetic material and is held in the file holder 35 by the magnetic retaining elements 37.

[0095] It is advantageous that the file insert element 36 can be designed with a simple geometric shape. The manufacture of the file insert element 36 is simplified.

[0096] The retaining grooves 22 provided for connection with the file body 2 are provided on the file holding element 35.

[0097] To ensure axial fixation along the longitudinal axis 3 of the file insert element 36 to the file holder element 35, a locking pin 38 oriented in the depth direction 16 is arranged to connect the file insert element 36 to the file holder element 35. The locking pin 38 also serves, in particular, to absorb shear forces that may occur along the longitudinal axis 3 during workpiece machining.

[0098] It is advantageous if a recess 39 is arranged in an edge region of the file element 6e, and in particular in the area of ​​a parting line between the file holder element 35 and the file insert element 36. The recess 39, which is particularly wedge-shaped, serves as a tool opening, in particular for the application of a lever tool, to separate the file insert element 36 from the file holder element 35 against the magnetic holding force.

[0099] The following refers to Figs. 16 and 17 Another embodiment is described. Structurally identical parts receive the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing "f".

[0100] This embodiment essentially corresponds to the previous embodiment, wherein the file element 6f is configured with a file holder element 35 and a file insert element 36. Transverse screws, extending along the depth direction 16, serve as retaining elements 37f to ensure a connection between the file insert element 36 and the file holder element 35. Specifically, the file insert element 36 has a through-hole, and the file holder element 35 has an internal thread for fastening that corresponds to the external thread of the retaining screw 37f.

[0101] In particular, the screws 37f are arranged outside the curved workpiece machining area 8 on the file insert element 36. Specifically, the retaining screws 37f are designed as countersunk screws and are set back from the outer surface 18. This ensures that the workpiece machining is not negatively affected by the screw connection.

[0102] In the following, we refer to Figs. 18 to 23 Another embodiment is described. Structurally identical parts use the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts use the same reference numerals with a trailing "g".

[0103] In the case of the file 1g, the file element 6g is designed in multiple parts with the file insert element 36g, which is held on the file holding element 35g, in particular screwed on.

[0104] The file insert element 36g is manufactured in one piece and has a projecting, rib-like machining rib 40. The machining rib 40 has the abrasive machining surface 8. The machining rib 40 has a concave surface.

[0105] The file insert element 36g has several through-holes, four in the illustrated embodiment. Retaining screws for attaching the file insert element 36g to the file holder element 35g can be screwed through these through-holes.

[0106] The file holder element 35g is designed in multiple parts and comprises a file holder element receptacle 41 and a file holder element guide 42. The file holder element guide 42 is designed in the shape of a web and has a rectangular and, in particular, square cross-sectional area in a plane perpendicular to a web longitudinal axis 43.

[0107] In a direction perpendicular to the longitudinal axis 43 of the guide rail, the file holder guide 42 has two guide bores 44, into each of which a sliding bushing 45 can be inserted. The guide bores 44 are continuous, extending over the entire height of the file holder guide 42. A dowel pin 46 is inserted into each of the sliding bushings 45 and is held in a recess in the file body 2g. The dowel pins 46 are oriented along the depth direction 16 of the file 1g. The file holder guide 42 is guided and displaceable along the dowel pins 46, i.e., along the depth direction 16, and in particular relative to the file body 2g.

[0108] Compression springs 21 are arranged on the underside of the file holder receptacle 41. The compression springs 21 are pre-tensioned between the file body 2g and the file holder 35g, such that a force is exerted on the file holder 35g in such a way that it is pushed away from the file body 2g and out of the recess 19.

[0109] The file holder guide 42 has a transverse through-bore 47 into which a transverse sliding bearing bushing 48 with a transverse pin 49 is inserted. The transverse through-bore 47 is oriented in a direction perpendicular to the longitudinal axis 43 of the web and perpendicular to the guide bores 44. The file holder guide 42 is held in the file holder receptacle 41 by the transverse pin 49, which is supported in the transverse sliding bearing bushing 48. The file holder receptacle 41 is pivotally mounted on the file holder guide 42 about the transverse pin 49. For this purpose, the file holder receptacle 41 has an elongated recess 50. In a plane perpendicular to the guide bores 44, the file holder guide 42 has an outer contour corresponding to the elongated recess 50.The file holder receptacle 41 has four threaded bores on its upper surface facing the file insert 36g, which correspond to the mounting holes on the file insert 36g. To accommodate the transverse pin 49, the file holder receptacle 41 has aligned transverse bores 51 opposite each other with respect to the recess 50. A threaded bore 75 is arranged perpendicular to each transverse bore 51. A setscrew (not shown) can be screwed into the threaded bore 75 to fix the transverse pin 49 in the respective transverse bore 51. For this purpose, the transverse pin 49, which has a cylindrical shape, may be flattened, at least in part.

[0110] Two retaining grooves 22g are provided on a side wall of the file holder receptacle 41. The retaining grooves 22g are cylindrical. The retaining grooves 22g may also have a non-circular inner contour, which may in particular be rectangular in a plane perpendicular to the longitudinal axis 52 of the groove. The retaining grooves 22g are designed as blind holes. The longitudinal axis 52 of the bore is inclined relative to a transverse axis of the transverse bore 51 at an angle of inclination n. The angle of inclination n is in particular less than 10°, in particular between 2° and 8°, in particular between 4° and 7°, and in particular between 5° and 6°. In particular, the angle of inclination n is 5.7°.

[0111] Each of the retaining grooves 22g engages a retaining element 24g. The retaining element 24g is shown enlarged. The retaining element 24g is an adjusting screw with a threaded section AG, a cylindrical section AZ, and a conical section AK. The external thread of the threaded section AG corresponds to a corresponding internal thread in a through-hole in the file body 2g. A locking set screw 25 can be arranged in a transverse bore oriented accordingly to secure the axial positioning of the retaining element 24g in the file body 2g.

[0112] The cylindrical section AZ has a core diameter that is smaller than the thread diameter of the threaded section AG. Based on the core diameter of the cylindrical section AZ, the conical section AK has an external cone angle k, which corresponds in particular to the inclination angle of the retaining groove 22g and is in particular identical to the inclination angle n. With the retaining element 24g, which is designed as a fine adjustment screw, adjustment of the file element 6g on the file body 2g along the depth direction 16 is possible with a precision of 1 / 1000 mm to 5 / 10000 mm.

[0113] The use of the sliding bushings 45 and the dowel pins 46 improves the adjustment of the file element 6g, as the sliding surfaces between the dowel pins 46 and the sliding bushings 45 are better protected from dust and chips. This allows for more precise movement, particularly with higher resolution. Horizontal stress on the retaining elements 24g and the corresponding bores in the file body 2g, especially in the working direction, is reduced and, in particular, becomes negligible.

[0114] Manufacturing and / or assembly tolerances of individual components can be specifically compensated for in the plane of movement of the file holder element 35g. It has been observed that tolerances in the range of 1 / 100 mm to 3 / 100 mm occur during the manufacturing of the machining rib 40 by wire EDM or fine milling and / or due to an uneven coating thickness with abrasive materials. When changing the file insert element 36g, a change in the zero position of the adjustment may be necessary, particularly with regard to manufacturing a machining rib 40 oriented perpendicular to the depth direction 16 and with regard to the lowest position of the machining rib 40 in the depth direction 16. Readjustments may also be necessary due to wear-related changes in the layer thickness of the abrasive material of the machining rib 40.In the illustrated embodiment, readjustments are made possible by the controlled file holder element guide 42 in the depth direction 16 and in particular by the axially mounted, tiltable file insert element receptacle and the fine adjustment.

[0115] Because the retaining element 24g has a conical section AK, there is no point contact in the retaining groove 22g, but rather line contact. This reduces the pressure between the retaining element 24g and the retaining groove 22g. The resulting load and wear between the adjusting screw (retaining element 24g) and the adjusting opening (retaining groove 22g) is more even.

[0116] The following will be based on Figs. 24 to 26Another embodiment is described. Structurally identical parts use the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts use the same reference numerals with a trailing "h".

[0117] Compared to the previous embodiment, one change is that the file holding element 35h is made in one piece.

[0118] The file insert element 36h can be inserted into the designated recess 39 in the file holder element 35h. Two threaded bores 66 are machined to the side of the recess 39, into which a retaining screw 37h is screwed and engages a corresponding shoulder 53 on the file insert element 36h. The file insert element 36h is clamped to the file holder element 35h by means of retaining screws (not shown). Attaching and, in particular, detaching the file insert element 36h from the file holder element 35h is straightforward. Replacing the file holder element 36h can be carried out quickly and efficiently.

[0119] Another difference is that the file holding element 35h has only a single retaining groove 22h, which is located centrally on the file body 2h or the file holding element 35h, particularly in the machining direction. Accordingly, a hinged mounting of the file holding element 35h as described in the previous embodiment is unnecessary.

[0120] The following refers to Fig. 27 and Fig. 28 Another embodiment is described. Structurally identical parts use the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts use the same reference numerals with a trailing "i".

[0121] In the file, the file body 2i is designed in two parts, wherein a first file body part, in which the recess 19 is formed, and a second file body part are arranged such that a closed file body 2i is formed. The parting line runs transversely to the machining direction 54 at an oblique angle s, which is in particular between 1° and 45°, in particular between 2° and 30°, and in particular between 5° and 15°. The parting surfaces of the first file body part and the second file body part facing the parting line correspond to each other. The parting surfaces are in particular each planar and allow for uncomplicated positioning of the file body parts relative to each other.

[0122] Two transverse bores 55 are arranged on one end face of the file body 2i for the variable-length design of the file body 2i. For this purpose, each transverse bore 55 has an internal threaded section 57 along the longitudinal axis 56 of the bore, a subsequent fitting section 58, and an external recessed section 59 open towards the end face. A correspondingly manufactured fitting screw can be screwed into the thread of the threaded section 57, enabling a reliable and precise connection of the file holder parts to one another, in particular such that the parting surfaces of the file holder parts are in contact. It is conceivable to provide several second file body parts with different length dimensions to form file bodies 2i of varying lengths.This makes it possible to adjust the file body with different length dimensions.

[0123] The following refers to Fig. 29 Another embodiment is described. Structurally identical parts have the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing "j".

[0124] Compared to the previous embodiment, the file body 2j allows for the targeted adjustment of the deformation of the non-abrasive sliding surface 9, particularly in an area laterally adjacent to the recess 19j, into which a file holder element with a file insert element can be inserted. This makes it possible to design the file body 2j with a convex or concave curvature in a surface area.

[0125] This is achieved in particular by designing the file body 2j in a portal-like manner in a plane oriented perpendicular to the machining direction 54, with two opposing web walls 60 and a ceiling wall 61 connecting the web walls 60. The sliding surface 9 is arranged on the ceiling wall 61. On an underside of the ceiling wall 61 opposite the sliding surface 9, particularly in the transition area to the web walls 60, stress relief notches can be arranged to reduce and, in particular, prevent stress concentrations in the file body 2j.

[0126] In a lower base area spaced from the ceiling wall 61, the web walls 60 are mechanically connected to each other by means of a tension / compression element 62, in particular in the form of a threaded rod. The tension / compression element 62 is fixed in a threaded internal bore in one of the web walls 60 and additionally held by an additional movement element 63 in the form of a nut. The threaded bore is designed as a blind hole.

[0127] On the opposite web wall 60, which has a through-opening, the tension / compression element is guided through the opening and secured by two fastening elements 63 arranged opposite each other on the opening. Tensile or compressive forces can be exerted on the web walls 60 using the tension / compression element 62. The tension / compression element 62 enables a mechanical coupling of the web walls 60. When a tensile force is exerted, a convex curvature forms on the non-abrasive sliding surface 9. When a compressive force is exerted on the web walls 60, a concave curvature forms on the non-abrasive sliding surface 9.

[0128] The following refers to Fig. 30Another embodiment is described. Structurally identical parts have the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts receive the same reference numerals with a trailing "k".

[0129] The file body 2k has a preloading element 64, which can be screwed into a designated opening on the underside of the file body 2k. The preloading element 64 interacts with an adjusting element 65 in the form of a perforated disc, which is located on the underside of the compression spring 21, i.e., opposite the file holding element 35. Depending on the screw-in depth of the preloading element 64, the adjusting element 65 is displaced, thereby reducing the depth of the recess for the compression spring 21 and thus increasing the preload on the compression spring 21. The preload provided by the compression spring 21 can be variably adjusted using the preloading element 64 and the adjusting element 65.

[0130] The following refers to Figs. 31 to 33Another embodiment is described. Structurally identical parts use the same reference numerals as in the previous embodiments, to whose description reference is hereby made. Structurally different, but functionally similar, parts use the same reference numerals with a trailing 1.

[0131] The file body 2l has at least one guide slot 67, in particular several guide slots 67, and in particular three parallel-oriented guide slots 67, which serve to receive the file elements 6l. In the longitudinal direction of the guide slots 67, collar spacing markings and / or internal dowel pins, arranged in corresponding bores or guide bushings in the file body 21, may be provided, which simplify the positioning of the file elements 6l at defined intervals with respect to the longitudinal direction. In particular, this makes it possible to arrange the file elements 6l side by side in the longitudinal direction such that different collars can be machined simultaneously with the file 11. For illustrative purposes, the file elements 6l are shown in Fig. 31 and 32The file elements 6l are shown arranged at equal intervals along the longitudinal slots 67. When the file elements 6l are arranged according to the scale, the distances between two adjacent file elements 6l differ accordingly. To facilitate the positioning of the file elements 6l, markings may also be provided on each file element 6l. It is understood that several markings, particularly for different scales, may be provided on the file body 2l.

[0132] The file elements 6l each have a file holding element 351 and a file insert element 361.

[0133] The file 11 enables the simultaneous processing of several fret bars on one instrument. In particular, the file elements 61 can be variably fixed relative to each other on the file body 21. The file elements 61 are each clamped to the file body 21 by means of the file holder element 351 via an abutment 74. Each file element 61 has mounting lugs 70 on its file holder element 351 that project into the guide slots 67, into which two clamping screws 68 engage. At least one spring element 71 is arranged on the underside of the file holder element 351 opposite the mounting lugs 70. In particular, two spring elements 71 are present, each designed as a resilient pressure piece, especially in the form of compression screws, with a spring-loaded pressure ball that engages in a corresponding recess in the file insert element 361.The spring elements 71 can be pressed or screwed into the respective recess. The spring movement of the file insert element 361 is maintained. Its slippage out of the file holding element 351 is prevented by a combined positive and force-fit connection.

[0134] Alternatively, the spring element 71 can be designed as a flat spring with which the file insert element 36l is supported on the file holder element 351. The flat spring is attached to an underside opposite the mounting lugs 70, in particular by screwing, riveting and / or welding, and can have a wave-shaped contour in a plane perpendicular to the longitudinal direction of the guide slots 67. The contour projects at least at one point into a corresponding recess in the file insert element 36l, so that a corresponding positive locking for the spring element is achieved.

[0135] The spring element 71 exerts a clamping force on the file insert elements 361, which holds the file insert elements 36l in a form-fitting and force-fitting manner in the file holding element 351.

[0136] It is advantageous if the file body 2l has sufficient flexibility, especially parallel to the long side of a fingerboard, i.e., perpendicular to the direction of processing. This makes it possible, in particular, to adapt the file body 2l to an uneven instrument neck.

[0137] The file insert elements 36l are designed analogously to the file element of the first embodiment. In particular, the depth stop function of these file elements 6l is not dependent on adjacent collar bar levels, but is based solely on the level of the collar bar being machined, i.e., directly. Fine adjustment of the file elements 61 on the file body 2l is unnecessary for the file 11. In particular, height differences of the non-abrasive vertex lines can be compensated for by the spring action of the file insert elements 361 by means of the spring elements 71. These height differences can be caused by manufacturing tolerances and / or by different material removal rates on different collar bars during their simultaneous machining.

[0138] The file insert elements 361, which are provided with a dovetail, are guided in particular by means of a corresponding dovetail guide 72 within the file holding elements 351 along the machining direction 54.

[0139] Impermissible displacements of the file insert elements 361 along the machining direction 54 can also be prevented by mechanical stop elements (not shown) arranged along the machining direction 54 of the file body 2l at the front and rear of the file body 2l and / or on the file holder element 351. In particular, fixed stop elements are provided. Specifically, the removable stop element is attached to the file body 21 and / or to the file holder element 351. Additionally or alternatively, recesses may be provided in the file insert element 361 that allow the spring element 71 to engage.

[0140] The stop elements are designed as flat-head screws, the heads of which are ground flat on one side to approximately one-third of their diameter. This rounded portion of the flat head prevents the file insert element 361 from being pulled out or pushed out. To avoid impeding the spring movement of the file insert element 361, the undersides of the screw heads may, in this position, have a gap of approximately 0.1 mm to 0.2 mm from the file insert element 361.

Claims

1. A file (1; 1a; 1b; 1c; 1d) for creating a non-planar contour, in particular with a transverse curvature, on a workpiece (11), wherein the file (1; 1a; 1b; 1c; 1d) comprises a. a longitudinal axis (3), b. at least one file element (5, 6; 5a, 6a; 5b; 5c; 5d) with an abrasive machining surface (8), c. a depth stop element (7; 7a; 7b; 7c; 7d) with a non-abrasive sliding surface (9), wherein the at least one file element (5, 6; 5a, 6a; 5b; 5c; 5d) and the depth stop element (7; 7a; 7b; 7c; 7d) are arranged next to one another in a plane orientated perpendicular to the longitudinal axis (3), wherein the depth-stop element (7a; 7b; 7c; 7d) forms a file base body (2a; 2b; 2c; 2d) on which at least one recess (19; 19d) for inserting the at least one file element (5a, 6a; 5b; 5c; 5d) is arranged, characterized in that - the at least one file element (5a, 6a) is arranged to be mechanically preloaded in the depth direction (16) on the file base body (2a), and / or - the at least one file element (5a, 6a; 5b) is arranged on the file base body (2a; 2b) so as to be adjustable in the depth direction (16).

2. A file (1; 1a; 1b; 1c; 1d) according to claim 1, characterized in that the at least one file element (5, 6; 5a, 6a; 5b; 5c; 5d) and the depth stop element (7; 7a; 7b; 7c; 7d) are connected to each other, in particular in pairs.

3. A file (1; 1a; 1b; 1c; 1d) according to any one of the preceding claims, characterized in that the abrasive machining surface (8) is designed to be concave and in particular has a curvature with a radius of curvature (RF) which is in particular greater than an original radius of curvature (RW) of the workpiece (11).

4. A file (1; 1a; 1b; 1c; 1d) according to any one of the preceding claims, characterized in that the at least one file element (5, 6; 5a, 6a; 5b; 5c; 5d) is profiled along the longitudinal axis (3).

5. A file (1; 1a; 1b; 1c; 1d) according to any one of the preceding claims, characterized in that the contour of the machining surface (8) and / or the sliding surface (9) is constant along the longitudinal axis (3).

6. A file (1; 1a; 1b; 1c; 1d) according to one of the preceding claims, characterized by a holding element (24; 24c; 24d) for holding the at least one file element (5a, 6a; 5b; 5c; 5d), in particular in the at least one recess (19; 19d).

7. A file (1; 1a; 1b; 1c; 1d) according to one of the preceding claims, characterized in that the at least one file element (5a, 6a; 5b; 5c; 5d) has an adjustment groove (22; 22c), in particular for holding engagement of the holding element (24; 24c; 24d), wherein the adjustment groove (22; 22c) extends in particular along the depth direction (16) of the file (1; 1a; 1b; 1c; 1d).

8. A file (1; 1a; 1b; 1c; 1d) according to claim 7, characterized in that the adjustment groove (22; 22c) has a variable groove depth (TN) in the depth direction (16) of the file (1; 1a; 1b; 1c; 1d).

9. A file (1; 1a; 1b; 1c; 1d) according to claim 7 or 8, characterized in that the adjustment groove (22; 22c) has a V-shaped groove profile in a plane perpendicular to the depth direction (16).

10. A file (1; 1a; 1b; 1c; 1d) according to one of the preceding claims, characterized in that the at least one file element (5a, 6a; 5b; 5c; 5d) is arranged on the file base body (2a; 2b; 2c; 2d) in such a manner that a minimum turning point (M) of the machining surface (8) lies in a plane (17, 18) defined by the sliding surface (9) or is set back from the plane (17, 18) by a vertical distance in the depth direction (16), wherein the distance is in particular less than 1.0 mm, in particular less than 0.7 mm, in particular less than 0.5 mm, in particular less than 0.3 mm, in particular less than 0.1 mm, and in particular greater than or equal to 0.001 mm.

11. A file (1; 1a; 1b; 1c; 1d) according to one of the preceding claims, characterized in that the at least one file element (5a, 6a) is arranged on the file base body (2a) by means of a compression spring (21).

12. A file (1; 1a; 1b; 1c; 1d) according to one of the preceding claims, characterized in that the at least one file element (5a, 6a; 5b) is arranged on the file base body (2a; 2b) so as to be adjustable in the depth direction (16) by means of a translation thread, in particular by means of a translation fine thread.

13. A file (1; 1a; 1b; 1c; 1d) according to any one of the preceding claims, characterized in that the at least one file element (6e; 6f) is designed in multiple pieces and in particular comprises a file holding element (35) and a file insert element (36) held by the file holding element (35).