Adjustable saw blade holder for a circular saw, and circular saw having such an adjustable saw blade holder

Abstract

The invention relates to an adjustable saw blade holder (10) for a circular saw (100), in particular a trimming circular saw. The saw blade holder (10) has a first holding device (30) for holding a first circular saw blade (16.1) and a second holding device (22) for holding a second circular saw blade (16.2), the second holding device (32) being adjustable relative to the first holding device (30). The first holding device (30) has an external thread (40), the thread crests (48) of which define the external diameter of the external thread (40), and the second holding device (32) has a plain bearing portion (46), which is mounted on the thread crests (48) of the external thread (40) so as to slide along the axis of rotation (34), and a threaded portion (44) with an internal thread (42), which engages into the external thread (40).

Description

Adjustable saw blade holder for a circular saw and circular saw with such an adjustable saw blade holder

[0001] The present invention relates to an adjustable saw blade holder for a circular saw, which can be configured in particular as an edging circular saw. Furthermore, the present invention relates to a circular saw, in particular an edging circular saw, in which the adjustable saw blade holder according to the invention is used.

[0002] Edgers, also known as double edgers or simply double edgers, are primarily used to create a clean edge (the "edge") on both opposite edges of sawn timber in a single operation. For example, they can be used to remove the bark or wane from a board cut from a log. This process is also called "edging."

[0003] Circular saws typically have at least one drive shaft, which is driven by a motor and on which several saw blades are mounted. Depending on the application, instead of just one drive shaft, two opposing, aligned drive shafts may be used, each with at least one saw blade mounted on it.

[0004] Since the trimming width can change depending on almost any workpiece, the axial position of at least one of the circular saw blades is adjustable in order to easily adapt the trimming width accordingly.

[0005] Often, edging is combined with crosscutting, which is why edging circular saws with more than two (e.g., three, four, five, six, or more) saw blades are used in many applications. With such edging circular saws, it is therefore possible to edge a board and simultaneously produce several boards / battens (also called "slats") at once.

[0006] The resulting trimming width and cutting width are determined by the axial distance between the circular saw blades arranged side by side along the axis of rotation. In the vast majority of modern edging circular saws, the trimming and / or cutting width is changed by an electronically controlled, motor-driven, or hydraulically actuated axial displacement of one or more circular saw blades.

[0007] EP 1 011 937 B1 shows an example of such a edging circular saw in which the individual circular saw blades are hydraulically adjusted by means of a rod construction which has several rods running parallel to the drive shaft, which penetrate the support bodies of the individual circular saw blades.

[0008] Other exemplary edging circular saws, such as the BKO 4 or BKO 6 from Esterer WD GmbH, are known in which the edging and / or cutting width adjustment is achieved by means of a drive shaft that has several telescopic sections. By means of a corresponding mechanism for the telescopic design of the drive shaft, the cutting dimensions can thus be changed within milliseconds.

[0009] It goes without saying that the increasing number of motor-adjustable telescopic sections is accompanied by a significant increase in the manufacturing costs of such edging circular saws. Therefore, in the area of ​​so-called external saws, which are formed by the circular saw blades positioned at the outermost points, flanges are frequently used on which two or more circular saw blades are mounted, and which in turn are mounted on the drive shaft of the edging circular saw. With these external saws, the cutting width usually does not need to be readjusted for each workpiece. Instead, the cutting width typically remains fixed for extended periods, allowing, for example, the production of a batch of boards with a fixed width at this position.

[0010] In the aforementioned examples of the BKO 4 and BKO 6 edging circular saws from Esterer WD GmbH, the two saw blades mounted on such a flange are currently fixed at a fixed distance from each other. This is usually achieved using a spacer ring positioned between the two saw blades on the flange. Changing the distance between the two saw blades mounted on such a flange therefore requires replacing the spacer ring. This necessitates removing the flange from the drive shaft, which is understandably time-consuming.

[0011] An adjustable saw blade holder for holding multiple circular saw blades, where the distance between the circular saw blades can be adjusted relatively easily without having to be removed from the drive shaft, would therefore be desirable.

[0012] The object of the present invention is to provide a saw blade holder for a circular saw, in particular a trimming circular saw, which serves as a holder for at least two circular saw blades and in which the distance between the circular saw blades can be adjusted in the simplest yet most precise way possible. In addition to the precision requirements, it is also important to ensure that such an adjustable saw blade holder does not take up too much space.

[0013] According to the invention, this problem is solved by an adjustable saw blade holder according to claim 1, which comprises: - a first holding device for holding a first circular saw blade, wherein the first holding device is designed to rotate about a rotation axis; - a second holding device for holding a second circular saw blade, wherein the second holding device is designed to rotate around the axis of rotation and is adjustable relative to the first holding device; wherein the first holding device has an external thread, the thread crests of which define an outside diameter of the external thread; and wherein the second holding device has a sliding bearing section which is slidably mounted on the thread crests of the external thread along the axis of rotation, and a threaded section with an internal thread which engages in the external thread.

[0014] The saw blade holder according to the invention thus serves to hold at least two circular saw blades, which are referred to herein as the "first circular saw blade" and the "second circular saw blade" and are held on separate holding devices (referred to herein as the "first holding device" and the "second holding device"). The two holding devices are connected to each other via a threaded connection. The first holding device has an external thread for this purpose. The second holding device has a corresponding internal thread that engages with the external thread.

[0015] Both the internal and external threads run along and around the axis of rotation. In other words, the axis of rotation of both holding devices also corresponds to the longitudinal axis of the external and internal threads.

[0016] The second holding device is mounted on or around the first holding device using this threaded connection. The distance between the two circular saw blades can be adjusted using this threaded connection.

[0017] The adjustable saw blade holder according to the invention is characterized not only by the general possibility of adjusting the distance between the two circular saw blades, but also by a kind of dual use of the external thread arranged on the first holding device. The external thread arranged on the first holding device interacts not only with the internal thread arranged on the threaded section of the second holding device in the usual manner, but also with a sliding bearing section arranged on the second holding device. More precisely, the sliding bearing section provided on the second holding device is slidably mounted on the thread crests of the external thread along the axis of rotation.

[0018] In other words, part of the second holding device (the threaded section with the internal thread) engages with the external thread, while another part of the second holding device (the sliding bearing section) is slidably mounted on the external thread.

[0019] This allows for a very simple, quick, yet very precise distance adjustment between the two holding devices of the saw blade holder.

[0020] The dual function of the external thread as both a thread and a sliding bearing offers the significant advantage of reducing the size of the adjustable saw blade holder. To ensure the adjustable axis positions of the two circular saw blades relative to each other, the second holding device is movable along the axis of rotation relative to the first. However, to prevent the second holding device from tilting relative to the first during operation of the circular saw, a sufficiently large bearing or contact surface must be provided for the second holding device to rest against the first. If such a bearing or contact surface were provided in addition to the external thread on the first holding device, for example...In the axial direction adjacent to the external thread, a first holding device would result, which, measured along the axis of rotation, would be relatively large and therefore space-consuming. However, the aforementioned dual function of the external thread allows precisely this to be avoided. Save on axial direction (parallel to the axis of rotation) without sacrificing precision.

[0021] The above-mentioned task has therefore been completely solved.

[0022] According to one embodiment, the second holding device has a first component and a second component which is detachably attached to the first component, wherein the sliding bearing section is arranged on the first component and the threaded section on the second component.

[0023] According to this embodiment, the second holding device is thus constructed in two parts. Preferably, the first component is detachably fastened to the second component by means of at least one fastening element. For example, the first component is detachably fastened to the second component by means of one or more fastening screws.

[0024] According to this design, the first component of the second holding device performs the aforementioned bearing function, while the second component of the second holding device performs the threading function.

[0025] According to a further embodiment, the first component of the second holding device is secured against rotation relative to the first holding device.

[0026] This anti-rotation device guarantees the torque transmission between the first and second holding devices, so that the two circular saw blades rotate synchronously with each other and are rotationally fixed to each other in the direction of rotation (around the axis of rotation).

[0027] According to a preferred embodiment, the anti-rotation device between the first component of the second holding device and the first holding device is achieved by means of a keyway connection. This keyway connection allows the first component of the second holding device to be displaceably mounted relative to the first holding device, preferably also parallel to the axis of rotation. This allows, on the one hand, axial support of the first component of the second holding device on the first holding device and, on the other hand, anti-rotation protection between the two holding devices.

[0028] According to a further embodiment, the groove of the keyway connection is preferably arranged on the first holding device, while the keyway of the keyway connection is arranged on the first component of the second holding device.

[0029] This allows for both the simple manufacture and assembly of the two holding devices.

[0030] In a further embodiment, the groove at least partially passes through the external thread. Preferably, the groove passes completely through the external thread.

[0031] Firstly, this allows for a space-saving arrangement. Secondly, it guarantees easy mounting of the second mounting device to the first mounting device.

[0032] According to a further embodiment, a clearance fit is provided between the sliding bearing section provided on the second holding device and the thread tips of the external thread provided on the first holding device.

[0033] In other words, the inner diameter of the sliding bearing section provided on the second holding device is equal to or slightly larger than the outer diameter of the external thread provided on the first holding device, so that a clearance fit is created between the sliding bearing section and the thread crests of the external thread.

[0034] This clearance fit enables, on the one hand, the aforementioned sliding bearing along the axis of rotation, and on the other hand, it serves for bearing in the radial direction between the two holding devices.

[0035] According to a further embodiment, the external thread is a thread whose thread tips in a longitudinal section of the external thread are flat and parallel to the axis of rotation.

[0036] The external thread is, for example, a trapezoidal thread or a flat thread. However, it is particularly preferred that the external thread be a pointed thread, such as a metric ISO thread or a metric ISO fine thread, whose thread tips have been turned or ground off. In other words, the external thread is preferably an external thread whose thread tips, viewed in longitudinal section, are flat or even and not pointed.

[0037] This results in a larger contact area for the sliding bearing section provided on the second holding device. This ensures improved sliding bearing between the two holding devices while still maintaining the threaded function of the engagement between the external and internal threads.

[0038] According to a further embodiment, the first holding device has a flange with a through-opening for mounting on a rotating shaft. The second holding device is preferably essentially ring-shaped and surrounds the flange.

[0039] Such a design of the saw blade holder according to the invention, in the form of a flange with a ring mounted thereon, has the advantage of being relatively easy to retrofit onto the rotary shaft of an existing circular saw. Furthermore, the saw blade holder according to the invention can thus also be easily replaced and mounted on the circular saw.

[0040] The two circular saw blades can be permanently or detachably connected to the saw blade holder. A detachable connection is always preferable, however, as this allows for easy replacement of the circular saw blades when worn.

[0041] Preferably, the first holding device has a first receptacle for the detachable holding of the first circular saw blade, while the second holding device has a second receptacle for the detachable holding of the second circular saw blade.

[0042] The first and second mounts are particularly well-suited for accommodating circular saw blades with the same inner diameter. This allows standardized circular saw blades to be mounted in both mounts.

[0043] According to a further embodiment, the second receptacle is arranged on the first component of the second holding device. In other words, the receptacle for the second circular saw blade is preferably arranged on the component of the second holding device on which the sliding bearing section and the anti-rotation device are also provided.

[0044] As already mentioned at the outset, the present invention relates not only to the saw blade holder itself (with and without circular saw blades mounted thereon) but also to a circular saw, in particular an edging circular saw, with the saw blade holder according to the invention. The embodiments mentioned above and those defined in the dependent claims thus relate not only to the saw blade holder itself, but also, correspondingly, to the circular saw according to the invention, which is equipped with such a saw blade holder.

[0045] According to one embodiment, the circular saw has a drive shaft on which the saw blade holder is detachably mounted.

[0046] This guarantees easy interchangeability of the entire saw blade holder, so that the circular saw can also be used without this saw blade holder if necessary, or a different type or differently dimensioned saw blade holder can be mounted on the circular saw instead.

[0047] It is understood that the aforementioned features and those to be explained below apply not only in the combinations specified, but also can be used in other combinations or on their own without leaving the scope of the present invention.

[0048] Exemplary embodiments of the invention are shown in the drawings and explained in the following description. They show: Fig. 1 shows a schematic view of an embodiment of a circular saw designed as an edging circular saw, in which the adjustable saw blade holder according to the invention can be used; Fig. 2 shows a schematic cross-sectional view of a wooden board with circular saw blades indicated in principle to illustrate a possible cutting pattern; Figs. 3A and 3B are perspective views of an embodiment of the adjustable saw blade holder according to the invention; Fig. 4 shows a front view of the adjustable [device] shown in Figs. 3A and 3B. Saw blade holder; Fig. 5 shows the sectional view AA of the adjustable saw blade holder indicated in Fig. 4; Fig. 6 shows the sectional view BB of the adjustable saw blade holder indicated in Fig. 4; and Fig. 7 shows the sectional view CC of the adjustable saw blade holder indicated in Fig. 4.

[0049] Fig. 1 schematically shows an embodiment of an edging circular saw in which the adjustable saw blade holder according to the invention can be used. The edging circular saw is designated by the reference numeral 100. The adjustable saw blade- The bracket is shown in different views in Figures 3-7 and is marked with the reference number 10.

[0050] The edging circular saw 100 is used particularly for wood processing. Figure 1 schematically shows a wooden board 12 being fed to the edging circular saw 100 along a feed direction 14. The wooden board 12 typically still has a wane or bark edge. This wane or bark edge is removed using the edging circular saw 100. Simultaneously, several cuts can be made with the edging circular saw 100, so that several boards of different desired widths can be produced from the wooden board 12 in just one operation.

[0051] Fig. 2 schematically illustrates a possible cutting pattern that can be produced with the edging circular saw 100. Here, a total of eight circular saw blades 16 are schematically indicated, arranged in a mirror-symmetrical pattern about a central axis 18 of the wooden board 12. In practice, such a mirror-symmetrical arrangement of the circular saw blades 16 is chosen in the vast majority of cases. However, the arrangement of the circular saw blades 16 does not necessarily have to be mirror-symmetrical, but is usually preferred due to a more even distribution of forces.

[0052] The two circular saw blades 16 arranged on the outermost sides of each side represent the circular saw blades of the so-called outer saws 20. In this example, the two outer saws 20 thus have a total of four circular saw blades 16. The two innermost circular saw blades 16 belong to the so-called inner saws 22. The circular saw blades 16 arranged between or in the middle belong to the so-called main saws 24.

[0053] As can be seen in Fig. 1, the saw blades 16 of the individual saws 20, 22, 24 are adjustable in their position relative to each other. To illustrate this, the left inner and main saws 22, 24 are shown fully extended, while the right inner and main saws 22, 24 are shown in their fully retracted positions. It is understood that the positions of the individual saws 20, 22, 24 shown in Fig. 1 do not correspond to the cutting pattern shown in Fig. 2, but rather This serves only to illustrate the possible position adjustment of the individual saws 20, 22, 24.

[0054] The edging circular saw 100 has a left sawing unit 102 and a right sawing unit 104, each equipped with an outer saw 20, an inner saw 22, and a main saw 24, as shown in Fig. 1. The circular saw blades 16 of the individual saws 20, 22, 24 are each mounted on a drive shaft 26, 26', which is driven rotaryally by a common drive motor 28. The circular saw blades 16 of the individual saws 20, 22, 24 are each arranged in an end-face region of the drive shafts 26, 26'. The adjustability of the circular saw blades 16 of the individual saws 20, 22, 24 relative to each other is ensured by a telescopic construction, which allows hydraulic or, alternatively, electric motor-driven adjustment of the individual saw blade positions relative to each other.

[0055] According to the previously known BKO 6 edging circular saw from Esterer WD GmbH, the two circular saw blades 16 of each of the two outer saws 20 were always fixed in their relative position to each other by a fixed spacer ring. Changing the distance between the circular saw blades 16 of the two outer saws 20 was therefore only possible by replacing the corresponding spacer element, which required disassembly of the outer saws 20 and was therefore time-consuming.

[0056] This problem is now solved by the adjustable saw blade holder 10 according to the invention, which allows for easy adjustment of the relative positions of the two saw blades 16.1 and 16.2 of the external saws 20.

[0057] It should be noted that the adjustable saw blade holder 10 is described here using the example of the outer saw 20 of the edging circular saw 100, but can in principle be used in any type of circular saw and is not limited to use within an outer saw. The adjustable saw blade holder according to the invention can, in principle, be flexibly mounted on any type of circular saw at different points on the drive shaft.

[0058] The adjustable saw blade holder 10 is designed as a flange construction according to the embodiment shown in Fig. 3-7. It can therefore be interchangeably mounted on the drive shaft 26 or 26' of the edging circular saw 100.

[0059] The saw blade holder 10 comprises a first holding device 30 designed as a flange and a second holding device 32 designed essentially in the shape of an annulus. The first holding device 30 serves to hold the first circular saw blade 16.1. The second holding device 32 serves to hold the second circular saw blade 16.2. Both holding devices 30, 32 are designed as bodies of revolution and are therefore preferably rotationally symmetrical about an axis of rotation 34.

[0060] According to the embodiment shown here, the two circular saw blades 16.1, 16.2 are each detachably attached to their respective holding devices 30, 32. In both cases, a retaining ring 36.1, 36.2 is used for fastening, which is attached to the respective holding device 30, 32 by means of several fastening screws 38.1, 38.2. The circular saw blades 16.1, 16.2 can thus be easily replaced in case of wear or other damage.

[0061] The second holding device, which is essentially ring-shaped, is arranged around the first holding device 30, which is designed as a flange. The position of the second holding device 32 relative to the first holding device 30 can be adjusted by means of a simple mechanical adjustment mechanism. In particular, this adjustment mechanism makes it possible to set the distance between the two circular saw blades 16.1 and 16.2, measured parallel to the axis of rotation 34. For this purpose, the first holding device 30 has an external thread 40 that engages with an internal thread 42 provided on the second holding device 32. The internal thread 42 is located on a threaded section 44 of the second holding device 32.

[0062] The external thread 40 and the internal thread 42 each run along and around the axis of rotation 34. In other words, the thread center axis of the internal thread 42 and the thread center axis of the external thread 40 coincide with the axis of rotation 34. In addition to the thread section The second holding device 32, on which the internal thread 42 is arranged, further comprises a sliding bearing section 46. The sliding bearing section 46 is designed as a cylindrical surface located on the inside of the annular second holding device 32, which faces the axis of rotation 34 and extends around it. The sliding bearing section 46 preferably borders directly on the threaded section 44.

[0063] The external thread 40 has a dual function. On the one hand, it serves as a support for the sliding bearing section 46, and on the other hand, it acts as a counterpart for the internal thread 42. As shown in Detail I in Fig. 5, the external thread 40 preferably has flattened thread crests 48 on which the sliding bearing section 46 of the second holding device 32 is slidably mounted.

[0064] The inner diameter of the sliding bearing section 46 is preferably adapted to the outer diameter of the thread 40 in such a way that a clearance fit is provided between the sliding bearing section 46 and the flattened or flat thread tips 48 of the external thread 40.

[0065] The thread tips 48 of the external thread 40 are aligned in the longitudinal section shown in Fig. 5 along the axis of rotation 34, flat and parallel to the axis of rotation 34.

[0066] The external thread 40 can, for example, be a trapezoidal thread. However, it is particularly preferred that the external thread 40 be a metric ISO thread whose thread crests are shortened along an imaginary cylinder running parallel to the axis of rotation 34. Particularly preferably, such a metric ISO thread is shortened by approximately half the flank height to remove or flatten its thread crests. This can be achieved, for example, by first producing a metric ISO thread, which is then uniformly turned or ground down. For example, the external thread 40 could be an M142 x 4 mm thread that has been turned down to a diameter of 140 mm.

[0067] The second holding device 32 is constructed in two parts. It comprises a first component 50 and a second component 52 detachably attached to it. The two components 50 and 52 are preferably detachably connected to one another by means of one or more fasteners. In the embodiment shown here, several clamping screws 54 serve as fasteners.

[0068] The sliding bearing section 46 is arranged on the first component 50, which can also be referred to as the adjusting hub. The detachable holder for the second circular saw blade 16.2 is also arranged on this first component 50, or adjusting hub. The internal thread 42 is arranged on the second component 52 of the second holding device 32, and engages with the external thread 40. This second component 52 can therefore also be referred to as a threaded ring, which serves to adjust the relative position of the second holding device 32 relative to the first holding device 30 and thus also to adjust the relative position of the two circular saw blades 16.1 and 16.2.

[0069] For fine adjustment, a dimensioning element or a vernier 56 of a corresponding measuring scale can be arranged on the outside of the first component, which is visible from the outside as indicated in Fig. 3A.

[0070] The first component 50 of the second holding device 32, designed as an adjusting hub, is further secured against rotation relative to the first holding device 30. A keyway connection 58, which is particularly visible in Fig. 6, serves as the anti-rotation device. This keyway connection 58 includes a key 60 arranged on the first component 50, which engages in a groove 62 that is formed in the outer surface of the first holding device 30, which is designed as a flange.

[0071] In the embodiment shown, the key 60 is detachably arranged on the first component 50 of the second holding device 32 by means of screws 64. The keyway connection 58 ensures, firstly, that the second holding device 32 is prevented from rotating and that torque is transmitted relative to the first holding device 30, and secondly, that the second holding device 32 is guided axially on the first holding device 30 parallel to the axis of rotation 34.

[0072] The groove 62 preferably passes completely through the external thread 40.

[0073] With the threaded ring (i.e., the first component 50 of the second holding device 32) loosened, the adjusting hub (i.e., the first component 52 of the second holding device 32) can thus be moved axially along the axis of rotation 34 relative to the first holding device 30. The position of the second circular saw blade 16.2 can be adjusted as follows: First, the clamping or holding screws 54 are loosened to detach the threaded ring 52 from the adjusting hub 50. The operator then holds the threaded ring 52 in place, for example, using a pin tool, and simultaneously turns one of the two circular saw blades 16.1, 16.2. Depending on the direction of rotation, the threaded ring 52 screws itself to the left or right on the external thread 40 of the first holding device 30, thereby reducing or increasing the distance between the two circular saw blades 16.1 , 16.2, as the adjusting hub 50 moves accordingly in the axial direction (parallel to the axis of rotation 34).During this adjustment movement, the sliding bearing section 46 of the adjusting hub 50 slides on the thread crests 48 of the external thread 40. The operator then continues turning until a desired dimension is reached, which can be read precisely using the vernier scale 56. Once this has occurred, the retaining or clamping screws 54 are tightened again. This fixes the second holding device 32 in its position relative to the first holding device 30 in the axial, radial, and circumferential directions, so that the saw blade holder 10 or the edging circular saw 100 is ready for use again.

[0074] This results in a very simple adjustment mechanism for setting the circular saw blade distance. The adjustment can therefore be made very quickly. Disassembly of the saw blade holder 10 from the edging circular saw 100 is not necessary. The adjustment can be made while the saw is mounted. Production interruptions can thus be reduced to a minimum.

[0075] Another significant advantage arises from the aforementioned dual function of the external thread 40. Since it serves simultaneously as a thread and as a sliding bearing surface, the entire saw blade holder 10 can be designed to be comparatively compact. Without the dual function of the external thread 40, an additional bearing surface adjacent to the flange or the first holding device 30 would be required. An external thread 40 is provided, which serves as a counterpart in front of the sliding bearing section arranged on the adjusting hub or the first component 50 of the second holding device 32. This would lead to a significant lengthening of the flange or the first holding device 30.

[0076] As an additional guidance improvement, it can be provided that the external thread 40 does not end in the undercut, but that its thread is designed to taper off.

[0077] A further advantage of the exemplary embodiment of the saw blade holder 10 shown here is that the two circular saw blades 16.1 and 16.2 are each arranged in identically sized receptacles of the first and second holding devices 30 and 32, respectively. Thus, the same circular saw blades 16 can be used interchangeably in both saw blade receptacles 106 and 108. To make this possible even in the present case, where the position adjustment mechanism is provided, an expanding mandrel was designed. This mandrel centers the second circular saw blade 16.2 on the adjustment hub or the first component 50 of the second holding device 32 as soon as the clamping screws 54 are tightened. This allows the second holding device 32 to be easily mounted on the first holding device 30 while still ensuring the centering of the second circular saw blade 16.2.

[0078] Furthermore, it should be noted that the comparatively small axial thread play of the external and internal threads 40 and 42 has proven to be harmless. For increased requirements, however, a second threaded ring can be used for locking in addition to the threaded ring (second component 52). This would, however, increase the overall length of the saw blade holder 10.

[0079] It is understood that various further variations and modifications can be made without departing from the scope of the present invention. For example, more than two circular saw blades can be mounted on the saw blade holder.

Claims

Patent claims 1. Adjustable saw blade holder (10) for a circular saw (100), in particular an edging circular saw, comprising: a first holding device (30) for holding a first circular saw blade (16.1), wherein the first holding device (30) is designed to rotate about a rotation axis (34); a second holding device (22) for holding a second circular saw blade (16.2), wherein the second holding device (32) is configured to rotate about the axis of rotation (34) and is adjustable relative to the first holding device (30); wherein the first holding device (30) has an external thread (40) the thread crests (48) of which define an outside diameter of the external thread (40); and wherein the second holding device (32) has a sliding bearing section (46) which is slidably mounted on the thread crests (48) of the external thread (40) along the axis of rotation (34), and a threaded section (44) with an internal thread (42) which engages in the external thread (40).

2. Adjustable saw blade holder according to claim 1, wherein the second holding device (32) comprises a first component (50) and a second component (52) which is detachably attached to the first component (50), and wherein the sliding bearing section (46) is arranged on the first component (50) and the threaded section (44) is arranged on the second component (52).

3. Adjustable saw blade holder according to claim 2, wherein the first component (50) of the second holding device (32) is secured against rotation relative to the first holding device (30).

4. Adjustable saw blade holder according to claim 3, wherein the first component (50) of the second holding device (32) is secured against rotation relative to the first holding device (30) by means of a keyway connection (58) and is displaceably mounted parallel to the axis of rotation (34).

5. Adjustable saw blade holder according to claim 4, wherein the groove (62) of the keyway connection (58) is arranged on the first holding device (30) and the key (60) of the keyway connection (58) is arranged on the first component (50) of the second holding device (32).

6. Adjustable saw blade holder according to claim 5, wherein the groove (60) at least partially passes through the external thread (40).

7. Adjustable saw blade holder according to one of claims 1-6, wherein a clearance fit is provided between the sliding bearing section (46) and the thread tips (48) of the external thread (40).

8. Adjustable saw blade holder according to one of claims 1-7, wherein the external thread (40) is a thread whose thread tips (48) in a longitudinal section of the external thread (40) are flat and parallel to the axis of rotation (34).

9. Adjustable saw blade holder according to one of claims 1-8, wherein the first holding device (30) has a flange with a through-opening for mounting on a rotating shaft (26), and wherein the second holding device (32) is substantially annular and surrounds the flange.

10. Adjustable saw blade holder according to one of claims 1-9, comprising a first circular saw blade (16.1) which is fixedly or detachably connected to the first holding device (30) and a second circular saw blade (16.2) which is fixedly or detachably connected to the second holding device (32).

11. Adjustable saw blade holder according to one of claims 1-10, wherein the first holding device (30) has a first receptacle (106) for the releasable holding of the first circular saw blade (16.1), and wherein the second holding device (32) has a second receptacle (108) for the releasable holding of the second circular saw blade (16.2).

12. Adjustable saw blade holder according to claim 11, wherein the first and second receptacles (106, 108) are designed to accommodate circular saw blades (16.1, 16.2) with the same inner diameters.

13. Adjustable saw blade holder according to claim 11 or 12, wherein the second receptacle (108) is arranged on the first component (50) of the second holding device (32).

14. Circular saw (100), in particular edging circular saw, with an adjustable saw blade holder (10) according to one of claims 1-13.

15. Circular saw according to claim 14, wherein the circular saw (100) has a drive shaft (26) on which the saw blade holder (10) is detachably mounted.

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