Circular saw

Abstract

The invention relates to a circular saw comprising a saw head (40) which receives a drive unit (47) with a drive shaft (47.1), wherein the drive shaft (47.1) is rotationally mounted on the saw head (40) by means of a shaft bearing (47.2), wherein: the drive shaft (47.1) carries a saw blade holder (45) on which a saw blade (46) can be exchangeably mounted; a saw blade receptacle (45.6) is provided which is designed to receive the saw blade (46) releasably mounted on the saw blade holder (45); the saw blade receptacle (45.6) has a receptacle inner side (45.7) and a receptacle outer side (45.8) spaced apart from the receptacle inner side (45.7) in the direction of the rotational axis of the drive shaft (47.1); the receptacle inner side (45.7) faces the shaft bearing (47.2), and the receptacle outer side (45.8) faces away from the shaft bearing (47.2) in the direction of the rotational axis of the drive shaft (47.1); a saw blade protective cover is provided which at least in some regions blocks access to the saw blade receptacle (45.6), in particular to the saw blade (46) held in the saw blade receptacle (45.6); the saw blade protective cover has a movable saw blade cover (60) which can be pivoted with respect to the saw head (40) by means of a protective cover bearing arrangement between a closed protective position and an open sawing position and which, in the closed protective position, is designed and arranged to cover, at least in some portions of the circumferential cutting region (46.1) of the saw blade, a saw blade (46) which can be mounted in or on the saw blade receptacle (45.6). In order to achieve a better transfer of force from the saw blade to the drive shaft and shaft bearing on such a circular saw, the invention proposes that the saw blade holder (45) is arranged between the protective cover bearing arrangement and the shaft bearing (47.1) of the drive shaft (47.1).

Description

[0001] circular saw

[0002] A circular saw with a saw head that accommodates a drive unit with a drive shaft, the drive shaft being rotatably mounted on the saw head by means of a shaft bearing, the drive shaft carrying a saw blade holder to which a saw blade can be replaceably mounted, a saw blade receptacle being provided that is designed to accommodate the saw blade that can be detachably mounted on the saw blade holder, the saw blade receptacle having an inner receptacle side and an outer receptacle side spaced apart from the inner receptacle side in the direction of the rotational axis of the drive shaft, the inner receptacle side facing the shaft bearing and the outer receptacle side facing away from the shaft bearing in the direction of the rotational axis of the drive shaft, a saw blade protective cover being provided that at least partially blocks access to the saw blade receptacle, in particular to the saw blade held in the saw blade receptacle,The saw blade protective cover comprises a movable saw blade cover that is pivotable relative to the saw head by means of a protective cover bearing arrangement between a closed protective position and an open sawing position, and that is designed and arranged to at least partially cover a saw blade mountable in the saw blade holder at its circumferential cutting area in the region of a cutting section of the saw in the closed protective position. The cutting section of the saw refers to the area of ​​a saw blade mountable in the saw blade holder that engages with the workpiece during machining.

[0003] Circular saws according to the invention can be, in particular, mobile or semi-stationary circular saws that are transported by a user to a location and used there. Accordingly, circular saws according to the invention can be cross-cut saws, cross-cutting saws, or pendulum-type saws.

[0004] In the case of circular saws according to the invention, the saw head can be pivotally mounted about a pivot axis, which can, for example, run parallel to the axis of rotation of the saw blade holder and can preferably form a cutting axis.

[0005] In circular saws according to the invention, a saw blade is mounted on a rotatable saw blade holder. A saw blade guard is associated with the saw blade. This guard comprises a fixed saw blade guard and a movable saw blade guard pivotally connected to the saw head.

[0006] The movable saw blade cover can be pivoted between a closed, protective position and an open or partially open sawing position. In the closed, protective position, the movable saw blade cover covers the cutting section of a saw blade housed in the saw blade holder of the saw head. When the movable saw blade cover is pivoted to the open or partially open sawing position, it exposes part of the cutting section of the saw blade. This exposed area allows a saw cut to be made in a workpiece.

[0007] From DE 10 2016 109 375 A1 a miter saw is known which has a saw head with a saw blade holder.

[0008] Modern circular saws are increasingly being integrated with functionalities. For example, braking systems can be provided that bring the saw blade to a stop in fractions of a second when a user enters the cutting area of ​​the saw blade. The abrupt braking effect imposes a high load on the saw blade and, via the saw blade, into the drive shaft and the shaft bearing. The object of the invention is therefore to create a circular saw of the type mentioned above that allows for improved power dissipation from the saw blade to the drive shaft and the shaft bearing.

[0009] This object is achieved by arranging the saw blade holder between the protective cover bearing assembly and the shaft bearing of the drive shaft. In particular, according to the invention, the saw blade holder can be arranged in the axial direction of the drive shaft between the protective cover bearing assembly and the shaft bearing of the drive shaft.

[0010] This object is also achieved by arranging the saw blade receiving area in the axial direction of the drive shaft at a distance of no more than two bearing widths of the shaft bearing of the drive shaft from the shaft bearing of the drive shaft. In particular, according to the invention, the saw blade receiving area is arranged in the axial direction of the drive shaft at a distance of no more than one bearing width of the shaft bearing of the drive shaft from the bearing of the shaft bearing.

[0011] This object is also achieved in that the saw blade receiving area is arranged in the axial direction of the drive shaft at a distance of less than half a bearing diameter of the drive shaft from the bearing of the drive shaft and / or the protective cover bearing arrangement is arranged in the axial direction of the drive shaft at a distance of less than a bearing diameter of the drive shaft from the bearing of the drive shaft.

[0012] In known circular saws, the protective cover bearing arrangement is usually arranged on the inside of the saw blade, facing the shaft bearing. The invention now takes a different approach by relocating the protective cover bearing arrangement to the outside of the saw blade. This allows the saw blade holder, and thus also the saw blade, to be moved close to the shaft bearing in the direction of the rotation axis. This results in a smaller lever arm between the saw blade, or rather the saw blade holder, and the shaft bearing. This leads to a significant reduction in the bending stress on the drive shaft. As a result, there is also improved force transmission into the shaft bearing. The circular saw according to the invention is thus significantly more resilient, which is particularly advantageous when equipped with a braking device acting on the saw blade.

[0013] A stable attachment of the protective cover bearing assembly is achieved in a simple manner if a support is attached to the saw head, which supports the protective cover bearing assembly and is arranged at least partially spaced from the outer side of the receptacle in an outer region of the saw head. This outer region of the saw head is arranged on the side of the outer side of the receptacle facing away from the shaft bearing, in the direction of the rotational axis of the drive shaft. The outer region of the saw head can be arranged inside a housing of the saw or outside the housing.

[0014] According to a preferred variant of the invention, it can be provided that the carrier has a bearing holder on which a bearing is held, wherein the axis of rotation of the bearing runs parallel, preferably in alignment, to the axis of rotation of the drive shaft, and that at least part of the movable saw blade cover is pivotally coupled to the carrier by means of the bearing. In this way, the movement kinematics of the movable saw blade cover can be coordinated with the geometry of the saw blade. In addition, simple bearings can then be used for the construction of the protective cover bearing arrangement. If the axis of rotation of the bearing is in alignment (or almost in alignment) with the axis of rotation of the drive shaft, this results in a compact design for the movable saw blade cover and simple pivot bearings, for example roller or plain bearings, can be used to mount the movable saw blade cover.

[0015] A possible variant of the invention can be such that a spacing area is formed between the protective cover bearing arrangement and the inside of the saw blade holder, in particular between the protective cover bearing arrangement and a saw blade support surface of the saw blade holder, which is accessible radially to the rotational axis of the saw blade holder. The saw blade can be easily mounted or removed via the radially accessible spacing area. In other words, a gap extending in the axial direction of the drive shaft is formed between the saw blade holder and the protective cover bearing arrangement, through which the saw blade can be removed in the radial direction of the drive shaft.

[0016] Preferably, it can also be provided that a clamping piece for clamping the saw blade to the saw blade holder is arranged at least partially in the spacing area between the protective cover bearing arrangement and the outer side of the saw blade holder, and that the saw blade holder is formed between the saw blade holder and the clamping piece. In particular, for easy assembly / disassembly of the saw blade, it can be provided that the clamping piece, in particular a tool holder of the clamping piece, is accessible through an access area of ​​the protective cover bearing arrangement, preferably in the axial direction of the drive shaft.

[0017] Within the scope of the invention, it may therefore also be the case, in particular, that the bearing arrangement has a passage through which a fastening element, in particular a fastening screw, for attaching the saw blade to the saw blade holder can be guided. For example, the fastening element can be used to connect the clamping piece to the drive shaft for attaching the saw blade. Preferably, the passage runs in alignment with the rotational axis of the drive shaft.

[0018] A conceivable variant of the invention can be such that the movable saw blade cover has a first cover segment and a second cover segment, which in the closed protective position each cover a partial area of ​​the saw blade holder, in particular each cover a partial area of ​​a saw blade mounted in the saw blade holder, and that these two cover segments are adjustable relative to one another. This allows the movable saw blade cover to be pivoted into the open sawing position in a space-saving manner. As a result of the smaller space requirement for the movable saw blade cover, additional installation space is available, which can be used for a compact design of the circular saw. For example, it is conceivable that a braking arrangement for braking the saw blade in the event of danger is installed, at least in part, in the installation space that is an extension of the pivoting movement of the movable saw blade cover.Preferably, the carrier can accommodate the two cover segments in a pivoting manner.

[0019] A space-saving and at the same time simply constructed construction results when it is provided that the bearing holder of the carrier is ring-shaped and that the bearing holder carries on its inner circumference the / a bearing for supporting the first cover segment and on its outer circumference a bearing part for supporting the second cover segment.

[0020] If, according to a variant of the invention, the first cover segment has a guide that cooperates with a guide element of the second cover segment to form a sliding guide, and the sliding guide guides the adjustment movement of the two cover segments relative to each other, then reliable adjustment of the two cover segments relative to each other can be guaranteed. In this case, the adjustment movement of the two cover segments relative to each other can preferably be limited in at least one adjustment direction by means of a limiting element to prevent possible operating errors.

[0021] If the movable saw blade cover is provided with at least one cover section, if the cover section covers an area of ​​the saw blade holder, in particular an area of ​​the saw blade, in the closed protective position, and if the cover section is preferably replaceably connected to the bearing assembly, the entire movable saw blade cover does not need to be replaced in the event of damage or wear. Rather, it is sufficient to replace only the damaged cover section.

[0022] The invention will be explained in more detail below with reference to an embodiment illustrated in the drawings. Figure 1 shows a perspective view of a circular saw designed as a crosscutting saw.

[0023] Figure 2 shows an assembly of the circular saw according to Figure 1 in perspective view,

[0024] Figure 3 shows the representation according to Figure 2 in a partially sectioned view,

[0025] Figure 4 shows a saw blade protective cover of the circular saw according to Figures 1-3,

[0026] Figure 5 shows the saw blade protective cover according to Figure 4 in a different perspective,

[0027] Figure 6 shows a detail of the saw blade protective cover according to Figures 4 and 5,

[0028] Figures 7 and 8 show a further detail of the saw blade protective cover according to Figures 4-6 and

[0029] Figure 9 shows a detailed view of the circular saw in vertical section.

[0030] Figure 1 shows a circular saw, specifically a sliding compound miter saw. This circular saw has a machine bed 10 that can be placed on a work surface via feet. The machine bed 10 has a bearing part 12 that includes a support section for a pivoting device 13. The pivoting device 13 can be pivoted in the bearing part 12 about a vertical pivot axis, allowing miter cuts to be made with the circular saw. A scale with an angular graduation is also provided in the area of ​​the support section to allow setting the desired pivot position of the pivoting device 13. The machine bed 10 and the pivoting device 13 form support surfaces 11 that are aligned with one another in one plane. Mounted on the machine bed 10 are two lateral stop pieces 17.1 of stops 17 that can be extended vertically by means of stop plates 17.2.

[0031] The stops 17 are used to position a workpiece to be machined, whereby the workpiece can be brought into contact with its rear side against the stop pieces 17.1 or the stop extensions 17.2.

[0032] At the front of the pivoting device 13, there is an extension arm 14, which carries a locking device 15 at its longitudinal end, comprising a clamping actuating element and a locking actuating element. The pivoting device 13 can be pivoted about its vertical pivot axis between fixed locking positions. To release the locking connection in a locking position, the pivoting device 13 must be unlocked using the locking actuating element. Between the locking positions, the pivoting device 13 can be continuously pivoted. The pivoting device 13 is fixed in an intermediate position using a clamping connection. This clamping connection can be released using the clamping actuating element.

[0033] The circular saw has a saw slot 16 which, as in the present embodiment, can extend in the area of ​​the pivoting device 13 and here, for example, is guided into the area of ​​the boom 14.

[0034] The saw slot 16 is bordered on both sides by boundary edges. Support surfaces 11 of the boundary edges extend on both sides of the saw slot 16. A chip deflector 50 can be provided adjacent to the saw slot 16 in the direction of the stops 17, by means of which sawdust can be diverted from the working area of ​​the circular saw.

[0035] Figure 1 further shows that the circular saw has a carrier 18, which is coupled to the machine bed 10 by means of a base via a pivot bearing with a horizontal pivot axis. The carrier 18 carries a head 20, which is supported on a bearing housing of the machine bed 10 via a pivot guide. In the area of ​​this support, the pivoting movement of the carrier 18 can be guided and the set position relative to the bearing housing can be fixed. A scale is provided on the bearing housing from which the pivot position can be read. The adjustment of the pivot positions of the carrier 18 relative to the bearing housing can be carried out, for example, using a coupling, in particular a gear, wherein the pivot position can be adjusted by the operator using an adjustment device.

[0036] Figure 1 further shows that the carrier 18, in the region of the head 20, has linear guide elements 21 that extend in the direction of the saw slot 16 and that linearly guide a saw carriage 30 in this direction. For this purpose, the saw carriage 30 has a base body on which linear bearing elements 31 are arranged. These linear bearing elements cooperate with the linear guide elements 21 of the carrier 18 to form the linear guide. The linear bearing elements are firmly connected to one another by means of a connecting section 32 formed by the head 20.

[0037] A saw head 40 is mounted on a carriage support 33 (see Figures 2 and 3) of the saw carriage 30 via a cross-cut bearing 34 with a horizontal pivot axis. The saw head 40 has a housing 41 with a stationary saw blade protective cover 44. A saw blade 46 is arranged within the housing 41. In the initial position shown in Figure 1, the saw blade 46 of the circular saw is additionally covered on its underside with a movable saw blade cover 60.

[0038] The housing 41 has a handle 42 with a switch 43. The circular saw can be activated with the switch 43. The handle 42 can be used to pivot the saw head 40 relative to the carriage support 33 about the horizontal pivot axis of the cross-cut bearing 34, so that the saw blade 46 can enter the saw slot 16, whereby the movable saw blade protective cover 60 opens to release the saw blade 46. In addition, the saw blade 46 can be adjusted together with the saw head 40 in the longitudinal direction of the saw slot 16. For this purpose, the saw head 40 is moved along the linear guide elements 21 of the support 18. In this way, a separating cut can be made in a workpiece. Figure 9 illustrates that a drive unit 47 with a drive shaft 47.1 can be installed within the housing 41 of the saw head 40. The drive shaft 47.1 is mounted on a bearing unit for rotation about a rotational axis D of the drive shaft 47.1. The bearing unit has a shaft bearing 47.2, which can be designed as a ball bearing, for example.

[0039] At its end protruding from the housing 41, the drive shaft 47.1 carries a saw blade holder 45 on a fastening section. The fastening section may form a pin-shaped end portion onto which the saw blade holder 45 is slid with a bore. The saw blade holder 45 may, for example, be ring-shaped, as shown in Figure 9. It has a saw blade contact surface 45.1 that may extend radially to the rotational axis D of the drive shaft 47.1. In the assembled state, the saw blade contact surface 45.1 defines a saw blade receptacle 45.6.

[0040] It may be the case that the saw blade contact surface 45.1 borders the inner surface 45.7 of the saw blade holder 45.6. This is illustrated in Figure 9.

[0041] The saw blade holder 45 may have a recess 45.2 radially inward of the saw blade contact surface 45.1. This recess 45.2 is set back from the saw blade contact surface 45.1 in the direction of the shaft bearing 47.2.

[0042] A saw blade 46 can be placed flat against the saw blade contact surface 45.1. The saw blade 46 has a central opening 46.2, which connects to the recess 45.2 of the saw blade holder 45. The saw blade 46 rests with its inner side against the saw blade contact surface 45.1.

[0043] A clamping piece 45.3 can be used to secure the saw blade 46. The clamping piece 45.3 has a centering projection 45.4 that extends through the opening 46.2 of the saw blade 46 and engages the recess 45.2 of the saw blade holder 45. Facing the saw blade 46, the clamping piece 45.3 has an inner clamping surface 45.9, which, when mounted, rests against the outside of the saw blade 46.

[0044] It may be that in the assembled state the clamping surface 45.9 limits the outer side 45.8 of the saw blade holder 45.6, as illustrated in Figure 9.

[0045] To attach the saw blade 46 to the drive shaft 47.1, a fastening element 45.5 is used, which can be designed as a screw, as in the present case. The fastening element 45.5 is passed through a central opening in the clamping piece 45.3 and screwed into an axial threaded receptacle of the drive shaft 47.1, as shown in Figure 9.

[0046] Tightening the fastening element 45.4 results in the saw blade 46 being clamped between the saw blade holder 45 and the clamping piece 45.3. In addition, the saw blade holder 45 is clamped against a support shoulder of the drive shaft 47.1.

[0047] Figure 1 shows that the movable saw blade cover 60 has a first cover segment 80 and a second cover segment 90. The two cover segments 80 and 90 are adjustable relative to each other and relative to the saw head 40. Due to this adjustment capability, the movable saw blade cover 60 can be moved from a closed protective position, as shown in Figure 1, into an open or partially open sawing position. In the sawing position, a cutting area 46.1 of the saw blade 46 is exposed, allowing a separating cut to be made in a workpiece.

[0048] As Figures 4 and 5 illustrate, the design may be such that the first cover segment 80 has a bearing piece 81 by means of which the first cover segment 80 can be pivoted about a pivot axis, as will be explained in more detail later.

[0049] The bearing piece 81 preferably forms a passage 81.1. The passage

[0050] 81.1 is dimensioned so that the fastening element 45.5 can be pushed through the passage 81. A transition section 82 is connected to the bearing piece 81, which supports an outer wall 84 at a shoulder 83. A toothed cover 85 is connected to the outer wall 84.

[0051] Figure 5 shows that it may be the case that an inner cover 86 can be connected to the tooth cover 85.

[0052] The outer wall 84 forms a cover section that, in the closed protective position of the movable saw blade cover 60, covers part of the outer side of the saw blade 46. Accordingly, the outer wall 84 is arranged on the side facing away from the shaft bearing 47.1, next to the outer side 45.8 of the saw blade holder 45.6. Accordingly, the outer wall 84 prevents access to the outer side of the saw blade 46 in the closed protective position.

[0053] The tooth cover 85 forms a cover section that covers the cutting area 46.1 of the saw blade 46 in the closed protective position of the movable saw blade cover 60. Accordingly, the tooth cover 85 encompasses the radially outer area of ​​the saw blade 46.1 and thus also the radially outer area of ​​the saw blade holder 45.6.

[0054] The inner cover 86 forms a cover section that, when the movable saw blade cover 46 is in the closed, protective position, covers part of the inside of the saw blade 46. Accordingly, the inner cover 86 is arranged on the side facing the shaft bearing 47.2, next to the inside of the receptacle 45.7 of the saw blade receptacle 45.6. Accordingly, the inner cover 86 prevents access to the inside of the saw blade 46 in the protective position.

[0055] It can be provided that the outer wall 84, the toothing cover 85 and / or the inner cover 86 are provided on a first cover segment 80.

[0056] Figure 5 shows that a guide 87 can be provided on the first cover segment 80. Preferably, the guide 87 is integrally connected to the first cover segment 80. In the present embodiment, the guide 87 is recessed in cross-section into the outer wall 84 in the form of a trough-shaped recess. Preferably, the guide 87 extends concentrically in its longitudinal extension to the pivot axis formed by the bearing piece 81.

[0057] To limit the pivoting movement of the two cover segments 80 and 90 relative to one another, a limiting element 88 can be provided on one of the cover segments 80, 90, which abuts against a counter-stop of the other cover segment 80, 90.

[0058] Advantageously, the first cover segment 80 can be constructed in two or more parts. In the present embodiment, the outer wall 84, the toothed cover 85, and / or the inner cover 86 form a one-piece molded body, which is preferably interchangeably connected to the projection 83.

[0059] The first cover segment 80 and the carrier 83 can be manufactured as a two-component part, for example from plastic and metal, wherein the extension 83 is made of metal and the molded body is made of plastic.

[0060] The second cover segment 90 has a bearing part 92.1 with a bearing 92 (see Figure 9). A projection 92.2 with a fastening section 92.3 is connected to the bearing part 92.1.

[0061] The second cover segment has a wall element 93 that supports an outer wall 94. A toothed cover 95 is connected to the outer wall 94, followed by an inner cover 96.

[0062] Similar to the first cover segment 80, the outer wall 94 forms an outer cover section that covers the outside of the receiving outer side 45.8 of the saw blade receiving element 45.6. The toothing cover 95 surrounds the cutting area 46.1 of the saw blade 46. The inner cover 96 adjoins the receiving inner side 45.7 of the saw blade receiving element 45.6 in the direction of the shaft bearing 47.1. It is not necessary for the components designed as cover sections, namely the outer wall 94, the toothing cover 95, and the inner cover 96, to be provided together on the second cover segment 90. Rather, the second cover segment 90 can have the outer wall 94, the toothing cover 95, and / or the inner cover 96 as a molded part.

[0063] The second cover segment 90 and the fastening section 92.3 can be manufactured as a two-component part, for example from plastic and metal, wherein the fastening section 92.3 is made of metal and the molded part is made of plastic.

[0064] The second cover segment 90 can be configured to include a guide element 97. The guide element 97 is configured and arranged to form a guide with the guide 87 of the first cover segment 80. The guide guides the adjusting movement of the first cover segment 80 relative to the second cover segment 90.

[0065] The guide element 97 may be integrally formed on the outer wall 94, as shown in Figure 5. Advantageously, the guide element 97 is designed as a projection that engages the guide 87 formed as a trough-shaped recess. The projection may be rib-shaped and extend concentrically to the pivot axis of the second cover segment 90.

[0066] As Figures 7-9 show, the first cover segment 80 and / or the second cover segment 90 are pivotally mounted on a support 70. Preferably, both cover segments 80 and 90 are pivotally mounted on the support 70.

[0067] The support 70 has an arm 71 with which it is attached to the pivoting saw head 40 (see Figures 1-3). Preferably, the arm 71 is detachably connected or connectable to the saw head 40 by means of fastening elements 72.

[0068] The carrier 70 may have a bearing holder 73 on the arm 71 at its end. A bearing 110 for supporting the first cover segment 80 is arranged on the bearing holder 73 (see Figure 9). The bearing 110 forms a pivot axis about which the first cover segment 80 can pivot.

[0069] As Figure 9 shows, the bearing 110 can preferably be designed as a rolling bearing, in particular as a ball bearing. The outer ring of the rolling bearing is inserted into the bearing holder

[0070] 73 and strikes a stop 74 of the support 70. The stop

[0071] 74 is preferably integrally formed on the bearing holder 73. The inner ring of the rolling bearing is pushed onto the outer side of the bearing piece 81, wherein the sliding movement is limited by a stop, which is formed, for example, by the transition section 82.

[0072] Additionally or alternatively, it can be provided that the second cover segment 90 is pivotally mounted on the carrier 70. For this purpose, the bearing holder 73 forms a bearing receptacle for the bearing part 92.1 of the second cover segment 90. Figure 7 illustrates that a plain bearing can be used to support the second cover segment 90. However, it is also conceivable that a rolling bearing is also used to support the second cover segment 90.

[0073] A retaining element 75, which can be designed as a snap ring, is provided to secure the bearing part 92.1 to the bearing holder 73. Thus, the bearing holder 73 has a circumferential groove into which the retaining element 75 is inserted.

[0074] As the drawings show, in order to achieve a compact size, it is advantageously provided that the two pivot bearings for the first and second cover segments 80, 90 are arranged one behind the other in the radial direction.

[0075] Advantageously, the pivot axes around which the two cover segments 80, 90 can pivot are aligned with each other.

[0076] According to Figure 9, it is advantageously provided that the rotation axis D is aligned with the pivot axes of the two cover segments 80, 90. Figure 9 further shows that the support 70, with its arm 71, extends in the direction of the rotation axis D on the side of the saw blade 46 facing away from the shaft bearing 74.2 and thus adjacent to the outer side 45.8 of the saw blade holder 45.6. Thus, the bearing arrangement by means of which the first and / or second cover segments 80, 90 are pivotally mounted is also held on this side.

[0077] Preferably, the saw blade holder 45 is arranged in the direction of the rotation axis D between the shaft bearing 47.2 and the bearing arrangement for the first and / or the second cover segment 80, 90. In this way, the shaft bearing 47.2 can be arranged in the direction of the rotation axis D at a short distance b from the saw blade holder 45 and thus at a short distance from the saw blade 46. This, on the one hand, achieves a compact design. On the other hand, the forces introduced into the drive shaft 47.1 via the saw blade 46 can be better dissipated and the bending stress on the drive shaft 47.1 can be reduced. In particular, this makes it possible to achieve a stress-optimized design for the drive shaft 47.1.

[0078] The distance “b” between the shaft bearing 47.2 and the saw blade holder 45, measured in the direction of the rotation axis D, is preferably a maximum of 3.5 millimeters, preferably a maximum of 1.5 millimeters, particularly preferably a maximum of 1 millimeter.

[0079] Additionally or alternatively, it can also be provided that the distance dimension “A” between the shaft bearing 47.2 and the saw blade support surface 45.1 of the saw blade holder 45, measured in the direction of the rotation axis D, is preferably a maximum of 15 millimeters, preferably a maximum of 12 millimeters, particularly preferably a maximum of 10 millimeters.

[0080] Figure 9 clearly shows how, in the closed protective position, the two cover segments 80, 90 protect the saw blade 46 from access by a user. The cover segments 80, 90 are designed such that one cover segment 90 can be pivoted into the installation space of the other cover segment 80, resulting in a compact arrangement in the partially opened or open sawing positions, as shown in Figure 3. Figure 3 also shows that the housing 41 of the saw head 40 has a pivoting receptacle into which at least one of the cover segments 80, 90, preferably both cover segments 80, 90, can be pivoted at least partially.

[0081] In the partially opened or open sawing position, it is advantageous that the projections of the cover segments 80, 90 in the direction of the rotation axis overlap at least partially in a plane, as illustrated in Figure 3. Thus, only a reduced size of the pivot mount is required within the housing 41.

[0082] Figure 3 illustrates that a braking unit 48 is housed in the housing 41 of the saw head 40. This braking unit 48 serves to act on the saw blade 46. A detection unit is provided that detects whether a user enters the cutting area 46.1 of the saw blade 46. The braking unit 48 is then activated, and the rotation of the saw blade 46 is stopped by the braking unit 48 in fractions of a second.

[0083] Since the movable saw blade cover 60 is segmented by means of the cover segments 80, 90 and thus only a small installation space is required for pivoting the movable saw blade cover 60 into the housing 41, the movable saw blade cover 60 can be pivoted, preferably completely, into the housing 41 or the brake unit 48 can be integrated into the housing 41 in a space-saving manner.

[0084] Figure 7 illustrates that a guide element 91 can be arranged on one of the cover segments 80, 90, preferably on the second cover segment 90, which guide element serves for the positively controlled pivoting of the cover segment(s) 80, 90.

[0085] The guide element 91 can have a sliding section 91.2, which is delimited by a support part 91.2. The support part 91.2 can preferably be detachably connected to the sliding section 91.2. Figure 3 illustrates that a guide lever 100 is pivotally attached to the saw carriage 30. For this purpose, the guide lever 100 has a joint piece 101, which is attached to a joint of the saw carriage 30. The guide lever 100 can be pivoted about the pivot axis of the joint. This pivot axis is parallel and spaced from the cross-cutting axis of the cross-cutting bearing 34. Opposite the joint piece 101, the guide lever 100 has a guide receptacle 102. The guide element 91 engages with its sliding section 91.2 in the guide receptacle 102. The support part 91.1 secures the guide lever 100 to the guide element 91.

[0086] In the pivoted-up rest position of the saw head 40 shown in Figure 2, the two cover segments 80, 90 are in the closed protective position, in which they protect the saw blade 46 from access. The sliding section 91.2 rests against the end of the guide receptacle 102 facing away from the joint piece 101. If the saw head 40 is now pivoted about the cross-cut bearing by means of the handle 42, the guide lever 100 is also forcibly pivoted. Due to the offset of the cross-cut bearing 34 from the pivot axis of the guide lever 100, a relative movement is caused between the saw head 40 and the guide receptacle 102. Due to this relative movement, the guide lever 100 continuously pulls the second cover segment 90, so that it is pivoted with its bearing part 92.1 relative to the carrier 70. The second cover segment 90 is pivoted into the intended pivoting area of ​​the housing 41.

[0087] Figure 6 shows a preferred embodiment in which a towing connection 120 is implemented between the two cover segments 80, 90. A freewheel 121 may be provided on one of the cover segments 80, 90. A towing element 122 is arranged on the other cover segment 80, 90. In the closed, protective position shown in Figure 6, the towing element 122 rests against an end stop 123 of the freewheel 121.

[0088] The freewheel 121 can be designed as a slot formed in one of the two cover segments. The drag element 122 can be designed as a projection that engages in this slot. When the second cover segment 90 is opened from the closed protective position, the drag element 122, which rests against the end stop 123, pulls the first cover segment 80 along, so that it pivots together with the second cover segment 90. Accordingly, the first cover segment 80 then releases the cutting section.

[0089] The saw blade can then plunge into a workpiece resting on the support surface 11 of the machine bed 10. During the cutting process, the first cover segment 80 then strikes the workpiece following the released cutting section. As the cutting progresses, the workpiece may pivot the first cover segment 80 relative to the second cover segment 90. The drag element 120 then releases from the end stop 123, and the drag element 122 is adjusted in the freewheel 121. The second cover segment 90 pivots into the first cover segment 80. This is shown in Figure 3.

[0090] The adjustment movement of the first cover segment 80 relative to the second cover segment 90 can preferably be limited by a limiting element 88 shown in Figure 5. As soon as the second cover segment 80 abuts the limiting element 88, the first cover segment 80 drags the second cover segment 90 along. In this case, the sliding section 91.2 can then be adjusted in the guide receptacle 102, as shown in Figure 3. Figure 3 shows the fully open sawing position.

[0091] Preferably, a return device 99, shown in Figures 5, 6 and 9, is activated when the two cover segments 80, 90 are adjusted relative to one another. The return device 99 is designed to pretension the two cover segments 80, 90 relative to one another when they are pivoted from the closed protective position shown in Figure 2 into an open or partially open sawing position. As Figure 6 shows, the return device can have a return spring 99.2, which acts between the two cover segments 80, 90 to generate the pretensioning force. For example, the return spring 99.2 can be inserted into a receptacle 98 of one of the two cover segments 80, 90. In the present exemplary embodiment, the receptacle 98 is formed by the second cover segment 90.

[0092] Preferably, the return spring 99.2 is designed as a helical spring.

[0093] For example, a mandrel 99.1 can be provided on the respective other cover segment 80, 90, which extends into the installation space surrounded by the coil spring and rests on one end of the coil spring. The other end of the coil spring rests on the base of the receptacle 98.

[0094] As Figure 5 shows, the mandrel 99.1 can be arranged on a support element 89 of the associated cover segment 80, 90.

[0095] When the cover segments 80, 90 are adjusted relative to each other from the closed protective position to the open sawing position, the mandrel 99.1 moves into the holder 98 and compresses the helical spring so that it is brought into a pre-tensioned state.

[0096] The return device 99 has the effect that when the saw head 40 is pivoted from the sawing position (for example according to Figure 3) in the direction of the starting position shown in Figure 2, the pretensioning force of the return spring 99.2 moves the cover segments 80, 90 towards each other in the direction of the closed protective position.

[0097] In Figure 3, for example, the first cover segment 80 is first pivoted clockwise toward the closed protective position. Due to the force of gravity, the second cover segment 90 also moves into the closed protective position, with the sliding section 91.2 being displaced again along the guide receptacle 102 until it reaches the position shown in Figure 2. The movable saw blade cover 60 is then completely returned to the closed protective position.

[0098] As Figure 3 illustrates, the guide lever 100 may have a deflection 103. This deflection 103 is designed to deflect the guide lever 100 around the brake unit 48 in the fully open sawing position, so that a compact design can be achieved.

[0099] The saw blade 46 can be easily replaced in the pivoted-open starting position shown in Figure 1. For this purpose, a tool is passed through the passage 81.1 of the bearing piece 81 of the first cover segment 80 and inserted into a tool holder 45.5.1 of the fastening element 45.5. The tool can be used to loosen the fastening element 45.5. If the fastening element 45.5 is a screw, it can be unscrewed from the threaded receptacle of the drive shaft 47.1. Since the passage 81.1 is sufficiently dimensioned, the fastening element 45.5 can be removed through the passage 81.1.

[0100] A spacing area A is formed between the saw blade support surface 45.1 and the bearing arrangement for pivoting the two cover segments 80, 90. This is sufficiently dimensioned to move the saw blade 46 together with the clamping piece 45.3 in the direction of the rotation axis until the clamping piece 45.3 is guided out of the recess 45.2. The saw blade 46 can then be guided radially outward in the spacing area and replaced with a new saw blade 46. To remove the saw blade 46, the movable saw blade cover 60 can be easily opened by hand, whereby the two cover segments 80, 90 are then pivoted into the housing 41.

[0101] As can be seen from the foregoing, the circular saw has a saw head 40 which forms a saw blade holder 45.6. A saw blade 46 is replaceably mountable on the saw head 40 on a rotatable saw blade holder 45 which can be driven by a drive unit 47. Preferably, a saw blade protective cover is provided which blocks access to the saw blade holder 45.6 at least in some areas, wherein the saw blade protective cover has a movable saw blade cover 60 which is adjustable relative to the saw head 40 between a closed protective position and an open sawing position and which is designed and arranged to at least partially cover the peripheral cutting area of ​​the saw blade 46 which can be mounted in the saw blade holder 45.6 in the closed protective position.For the purposes of a compact design, it can be provided that the movable saw blade cover 60 has a first cover segment 80 and a second cover segment 90, which in the closed protective position each cover a partial area of ​​the saw blade holder 45.6 and that these two cover segments 70, 80 are adjustable relative to one another and relative to the saw head 40.

Claims

Claims 1. Circular saw with a saw head (40) which accommodates a drive unit (47) with a drive shaft (47.1), wherein the drive shaft (47.1) is rotatably mounted on the saw head (40) by means of a shaft bearing (47.2), wherein the drive shaft (47.1) carries a saw blade holder (45) on which a saw blade (46) can be exchangeably mounted, wherein a saw blade receptacle (45.6) is provided which is designed to accommodate the saw blade (46) which can be detachably mounted on the saw blade holder (45), wherein the saw blade receptacle (45.6) has a receptacle inner side (45.7) and an inner side in the direction of the rotational axis of the drive shaft (47.1) for receiving (45.7) spaced apart receiving outer side (45.8), wherein the receiving inner side (45.7) faces the shaft bearing (47.2) and the receiving outer side (45.8) is arranged facing away from the shaft bearing (47.2) in the direction of the rotational axis of the drive shaft (47.1), wherein a saw blade protective cover is provided which at least partially blocks access to the saw blade holder (45.6), in particular to the saw blade (46) held in the saw blade holder (45.6), wherein the saw blade protective cover has a movable saw blade cover (60) which is pivotable relative to the saw head (40) by means of a protective cover bearing arrangement between a closed protective position and an open sawing position and which is designed and arranged to at least partially cover a saw blade (46) mountable in the saw blade holder (45.6) at its peripheral cutting area (46.1) in a cutting section of the saw in the closed protective position, characterized in that the saw blade holder (45) is arranged between the protective cover bearing arrangement and the shaft bearing (47.1) of the Drive shaft (47.1 ) is arranged.

2. Circular saw according to claim 1, characterized in that a carrier (70) is fastened to the saw head (40), which carrier carries the protective cover bearing arrangement and which is arranged at least partially spaced from the receiving outer side (45.8) in a saw head outer region, wherein this saw head outer region is arranged on the side of the receiving outer side (45.8) facing away from the shaft bearing in the direction of the axis of rotation of the drive shaft (47.1).

3. Circular saw according to claim 2, characterized in that the carrier (70) has a bearing holder (73) on which a bearing (1 10) is held, wherein the axis of rotation of the bearing (1 10) runs parallel, preferably in alignment, to the axis of rotation of the drive shaft (47.1), and that by means of the bearing (1 10) at least a part of the movable saw blade cover (60) is pivotally coupled to the carrier (70).

4. Circular saw according to one of claims 1 to 3, characterized in that between the protective cover bearing arrangement and the receiving inner side (45.7) of the saw blade receiving means (45.6), in particular between the protective cover bearing arrangement and a saw blade support surface (45.1) of the saw blade holder (45), a spacing region (A) is formed which is accessible radially to the rotational axis of the saw blade holder (45).

5. Circular saw according to one of claims 1 to 4, characterized in that at least in some areas in the distance region (A) between the protective cover bearing arrangement and the receiving outer side (45.8) of the saw blade receiving means (45.6) a clamping piece (45.3) for clamping the saw blade (46) to the saw blade holder (45) is arranged, and that the saw blade receiving means is formed between the saw blade holder (45) and the clamping piece (45.3).

6. Circular saw according to one of claims 1 to 5, characterized in that the bearing arrangement has a passage (81.1) through which a fastening element (45.5), in particular a fastening screw, for fastening the saw blade (46) to the saw blade holder (45) can be guided.

7. Circular saw according to claim 6, characterized in that the passage (81 .1 ) is aligned with the axis of rotation of the drive shaft (47.1 ).

8. Circular saw according to one of claims 1 to 7, characterized in that the movable saw blade cover (60) has a first cover segment (80) and a second cover segment (90) which in the closed protective position each cover a partial area of ​​the saw blade holder, in particular each cover a partial area of ​​a saw blade (46) mounted in the saw blade holder, and that these two cover segments (80, 90) are adjustable relative to one another.

9. Circular saw according to claim 8, characterized in that the carrier (70) receives the two cover segments (80, 90) in a rotatable manner.

10. Circular saw according to one of claims 8 or 9, characterized in that the bearing holder (73) is annular, and that the bearing holder (73) carries on its inner circumference the / a bearing (110) for supporting the first cover segment (80) and on its outer circumference a bearing part (92.1) for supporting the second cover segment (90).

11. Circular saw according to one of claims 8 to 10, characterized in that the first cover segment (80) has a guide (87) which cooperates with a guide element (97) of the second cover segment (90) to form a sliding guide, and in that the sliding guide guides the adjusting movement of the two cover segments (80, 90) against each other.

12. Circular saw according to claim 11, characterized in that the adjusting movement of the two cover segments (80, 90) relative to each other is limited in at least one adjusting direction by means of one or more limiting elements (88).

13. Circular saw according to one of claims 8 to 12, characterized in that the movable saw blade cover (60) has at least one cover section, that the cover section in the closed protective position covers an area of ​​the saw blade holder (45.6), in particular an area of ​​the saw blade (46), and that the cover section is preferably exchangeably connected to the bearing arrangement.

14. Circular saw according to claim 13, characterized in that the cover section has a saw blade (46) mounted in the saw blade holder (45.6) on whose radially outer circumferential cutting area (49.1) is surrounded by a toothing cover (85, 95), and / or that the cover section covers a saw blade (46) mounted in the saw blade holder (45.6) on its outer side facing away from the saw blade holder (45) with an outer wall (84, 94), and / or that the cover section covers a saw blade (46) mounted in the saw blade holder (45.6) on its inner side facing the saw blade holder (45) with an inner cover (86, 96).

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