Motorized chain saw and method for tensioning the saw chain of a motorized chain saw

Abstract

The invention relates to a motorized chain saw and a method for tensioning a saw chain of a motorized chain saw, in particular a motorized chain saw with a housing (2) and a drive motor (3). A guide rail (5) is held at the housing (2) via a releasable fastening device (8) and can be moved relative to the housing (2) in the direction of the longitudinal axis (6) of the guide rail via a tensioning device (10) when the fastening device (8) is released. The motorized chain saw (1) comprises a chain lifting device (11) which is constructed separately from the tensioning device (10). The chain lifting device (11) is configured for deflecting the saw chain (7) in a deflection position (40) of the chain lifting device (11) when the tensioning device (10) tensions the saw chain (7) and relaxing the saw chain (7) in an operating position (41) of the chain lifting device (11) when the guide rail (5) is fastened.

Description

Technical Field

[0001] This invention relates to a motorized chainsaw. It also relates to a method for tensioning the saw chain of a motorized chainsaw. Background Technology

[0002] In principle, a motorized chainsaw with a housing and a drive motor is known, wherein the drive motor drives the saw chain, guided in a guide slot in a guide rail, via a drive sprocket. The guide rail is held in place in the housing by a releasable fixing device. If the fixing device is released, the guide rail can be moved relative to the housing along its longitudinal axis via a tensioning device. This tensions the saw chain.

[0003] Retensioning such motorized chainsaws is often difficult, especially for individual users who lack sufficient experience to select the correct tension for the chain. If the chain is too tightly tensioned, friction between the chain and the guide rail increases, resulting in increased wear on the components. If the chain is too loosely tensioned, this can cause the chain to slip off the guide rail or the drive sprocket. This can damage the chain or other components of the motorized chainsaw. Particularly in the case of motorized chainsaws with only low motor power, especially bush cutters, the range of tension that must be adjusted is relatively small. Therefore, retensioning the chain is particularly difficult for the operator in such motorized chainsaws. Summary of the Invention

[0004] Therefore, the present invention is based on the following objective: to further develop a motorized chainsaw so that tensioning the chainsaw chain can be achieved in a simple manner for the operator.

[0005] The task is solved by a motorized chainsaw having a housing and a drive motor, wherein the drive motor drives a saw chain guided in a guide slot in a guide rail via a drive sprocket, wherein the guide rail has a longitudinal plane extending from the guide slot, wherein the guide rail is held in the housing by a releasable fixing device and is movable relative to the housing via a tensioning device along the longitudinal axis of the guide rail when the fixing device is released, wherein the motorized chainsaw includes a chain lifting device separately constructed from the tensioning device, and wherein the chain lifting device is configured to deflect the saw chain in an offset position of the chain lifting device when the tensioning device tensions the saw chain, and to slack the saw chain in an operating position of the chain lifting device when the guide rail is fixed.

[0006] The present invention is based on another objective, namely, to provide a method for tensioning the saw chain of a motorized chainsaw, the method enabling the operator to tension the saw chain in a simple manner.

[0007] The task is accomplished by a method for tensioning the saw chain of a motorized chainsaw, wherein the motorized chainsaw includes a housing and a drive motor, wherein the drive motor drives the saw chain guided on a guide rail around a drive sprocket, wherein the guide rail is held in the housing by a releasable fixing device and is movable relative to the housing via a tensioning device along the longitudinal axis of the guide rail when the fixing device is released, wherein the chain lifting device of the motorized chainsaw deflects the saw chain in an offset position of the chain lifting device when the tensioning device tensions the saw chain, and slackens the saw chain in an operating position of the chain lifting device when the guide rail is fixed.

[0008] A motorized chainsaw includes a housing and a drive motor. The drive motor drives a saw chain guided in a guide slot in a guide rail via a drive sprocket. The guide rail has a longitudinal plane extending from the guide slot. The guide rail is held in place in the housing by a releasable fixing device. When the fixing device is released, the guide rail can move relative to the housing along its longitudinal axis via a tensioning device. The motorized chainsaw includes a chain lifting device constructed separately from the tensioning device. The chain lifting device is configured to deflect the saw chain in an offset position when the tensioning device tensions the saw chain. Furthermore, the chain lifting device is configured to slack the saw chain in an operating position when the guide rail is fixed.

[0009] Therefore, to retension the saw chain, the fixing device of the motorized chainsaw should be loosened, wherein the tensioning device guide rail is pushed forward away from the drive sprocket along its longitudinal axis, and the saw chain is tensioned. During chain tensioning, the chain lifting device is in its offset position, thereby offsetting the saw chain via the chain lifting device. The guide rail is then fixed by the fixing device. In this fixed position of the fixing device, the chain lifting device is in the running position, in which the saw chain no longer offsets via the chain lifting device. In this position, the guide rail is clamped and held in place by the fixing device. In the running position of the chain lifting device, the saw chain is slack. A targeted, predetermined chain gap is adjusted based on the initial offset of the saw chain. Increased tension of the saw chain and the associated friction are avoided. This prevents the saw chain from being retensioned with excessive tension.

[0010] The chain lifting device preferably includes an offset element acting on the saw chain. The offset element of the chain lifting device offsets the saw chain. A guide rail is formed to guide the saw chain, wherein the offset element preferably lifts the saw chain from the guide rail a predetermined distance in the offset position of the chain lifting device. This predetermined distance creates a desired chain gap in the slack state of the saw chain, i.e., in the operating position of the chain lifting device. This allows for reproducible adjustment of the same tension force in a simple manner when retensioning the saw chain.

[0011] Advantageously, the saw chain is positioned against the offset element of the chain lifting device in the offset position. The offset of the saw chain can be precisely adjusted through direct contact between the offset element of the chain lifting device and the saw chain. Alternatively, a magnet, especially an electromagnet, can be used to offset the chain using magnetic force.

[0012] The offset element of the chain lifting device is preferably capable of lateral movement relative to the longitudinal plane. This allows the offset element to move into and out of the guide slot. The offset element of the chain lifting device is preferably pivotally supported relative to the guide slot. In the offset position, the offset element pivots into the guide slot and lifts the saw chain away from the bottom of the guide slot. In the running position, the offset element pivots laterally out of the guide slot, allowing the saw chain to move towards the bottom of the guide slot. This ensures a predetermined chain clearance. The offset element is preferably arranged on the underside of the guide rail. Due to gravity, the saw chain hangs below the guide rail, providing sufficient space for the offset element of the chain lifting device to pivot into the guide slot.

[0013] Advantageously, the offset element is positioned such that, in the offset position, it extends into the guide groove of the guide rail and lifts the drive link of the saw chain away from the bottom of the groove. In the running position, the offset element rotates out of the guide groove to such an extent that the drive link of the saw chain can then descend toward the bottom of the groove.

[0014] Preferably, an adjusting element is provided for moving the offset element. Preferably, in the operating position of the chain lifting device, the adjusting element acts on the offset element. Here, the adjusting element acts on the offset element such that the offset element is pressed out of the guide slot, and the guide slot for the drive link of the saw chain is released.

[0015] The offset element is preferably constructed as a single piece with the guide rail. This allows for a simple construction and assembly of the motorized chainsaw.

[0016] Advantageously, the fixing device acts on the chain lifting device such that the chain lifting device is in the running position within the fixed position of the fixing device. Advantageously, the fixing device and the chain lifting device are coordinated such that the guide rail is tensioned by the tensioning device when the fixing device is released, and the chain lifting device is in the offset position. Through the combined action of the fixing device and the chain lifting device, the operator can easily adjust the preload of the saw chain. The operator only needs to loosen or tighten the fixing device, while simultaneously activating or deactivating the chain lifting device. This avoids operator errors when tensioning the saw chain.

[0017] Specifically, the tensioning device is configured such that it includes a spring element that pre-tensions the guide rail away from the housing along the longitudinal axis of the guide rail. This automatically pre-tensions the saw chain. The operator has no control over the magnitude of the tension force, thus avoiding fluctuations in the pre-tension force of the saw chain. This ensures a roughly consistent pre-tension force on the saw chain during each new tensioning process. The tension force used to push the guide rail forward and pre-tension the saw chain corresponds to the spring force of the spring element. This avoids excessive tension that might occur when manually moving the guide rail.

[0018] Advantageously, the fixing device and the chain lifting device are coordinated such that the fixing device holds the guide rail in a partially detached position, and the chain lifting device is in an offset position. Thus, when the saw chain is re-tensioned, the offset element first engages in the guide slot and then tensions the saw chain. This ensures that the offset element is positioned between the drive link of the saw chain and the bottom of the slot in the guide rail before the saw chain is tensioned. If the guide rail is pre-tensioned before the offset element pivots into the guide slot, the offset element will only pivot laterally toward the saw chain. Offset of the saw chain away from the bottom of the slot in the guide rail is no longer possible. In an alternative embodiment, it may be suitable that the offset element has an inclined portion constructed at its end facing the saw chain. The inclined portion is constructed such that the saw chain is pushed away from the bottom of the slot via the inclined portion of the offset element when it comes into lateral contact with the offset element. This also tensions the saw chain.

[0019] Advantageously, the fixing device includes a sprocket cover and a clamping element disposed on the sprocket cover, wherein the guide rail is pressed against the housing via the clamping element. Therefore, the guide rail is preferably held clamped directly between the housing and the clamping element. The fixing device preferably includes a spring unit, wherein the clamping element is supported on the sprocket cover transversely to the longitudinal plane of the guide rail via the spring unit. A spring force applied by the spring unit acts transversely to the longitudinal plane of the guide rail. Here, the spring unit supports and presses the clamping element against the guide rail via the sprocket cover.

[0020] In the fixed position of the fixing device and in the partially detached position of the fixing device, the clamping force acting on the guide rail by the clamping element is preferably greater than the tensioning force acting on the guide rail by the tensioning device. This achieves a two-stage tensioning process for the saw chain. When changing from the fixed position of the fixing device to the partially detached position, only the offset element pivots into the guide groove. The guide rail remains clamped by the preload of the clamping element. The clamping force is greater than the tensioning force of the tensioning device. Only after the offset element pivots into the guide groove can the fixing device be completely released, thereby eliminating the clamping force and tensioning the guide rail forward. In this position of the fixing device, the clamping force acting on the guide rail is less than the tensioning force. The saw chain is tensioned and rests against the offset element.

[0021] The fixed position of the fixing device can then be re-occupied. The guide rail is clamped against the housing and fixed thereby by the clamping element. The offset element is pressed out of the guide groove by the adjusting element. The operating position of the chain lifting device is then occupied again, and the saw chain is tensioned again with the predetermined chain gap. Attached Figure Description

[0022] Other features of the invention will become apparent from the specification and accompanying drawings, in which embodiments of the invention described in detail below are illustrated. In the drawings:

[0023] Figure 1 The motorized chainsaw is shown in a side view;

[0024] Figure 2 A partial view shows the guide rail with the chain lifting device;

[0025] Figure 3 A partial side view shows the chain lifting device in the offset position with the saw chain at maximum tension;

[0026] Figure 4 A partial side view shows the chain lifting device in the operating position with the saw chain under pre-limited tension;

[0027] Figure 5 A partial side view shows the chain lifting device in an offset position with the saw chain unstressed;

[0028] Figure 6 Along Figure 1 Arrow V in the diagram shows the motorized chainsaw in the offset position of the chain lifting device, in the position where the fixing device is partially detached;

[0029] Figure 7 Along Figure 1 Arrow V in the diagram shows the motorized chainsaw in the fixed position of the fixed device in the operating position of the chain lifting device;

[0030] Figure 8 The first side element of the guide rail is shown in a side view;

[0031] Figure 9 The second side element of the guide rail is shown in a side view;

[0032] Figure 10 The middle element of the guide rail is shown in a side view;

[0033] Figure 11 The guide rail is shown in its assembled state in a side view; and

[0034] Figure 12 A perspective cross-sectional view shows a motorized chainsaw with a spring element. Detailed Implementation

[0035] exist Figure 1 The image shows a hand-guided motorized chainsaw according to the present invention, configured as a bush cutter in this embodiment. The motorized chainsaw 1 includes a housing 2 having a handle 35. Furthermore, the motorized chainsaw 1 includes a drive motor 3 (shown schematically only), a guide rail 5, and a saw chain 7. The saw chain 7 is driven by the drive motor 3 via a drive sprocket 4 (…). Figure 2 The drive motor 3 is driven around the guide rail 5. In this embodiment, the drive motor 3 is configured as an electric motor, which is powered by a battery 37. In this embodiment, the battery 37 is located at the rear end of the handle 35. The electric motor can also be powered via a connecting cable. In an alternative embodiment, the drive motor 3 can also be configured as an internal combustion engine, particularly as a two-stroke engine or a four-stroke engine with mixed lubrication.

[0036] like Figure 1 As shown, the guide rail 5 extends forward on the side of the housing 2 opposite to the handle 35. A pivotable cover 36 is arranged on the housing 2, extending along the guide rail 5 and at least partially extending beyond the guide rail 5. The cover 36 can pivot away from the guide rail 5 in an upward direction.

[0037] like Figure 1 As shown, the motorized chainsaw 1 includes a releasable fixing device 8, via which the guide rail 5 is held at the housing 2. The fixing device 8 includes a sprocket cover 15 and a clamping element 16 disposed on the sprocket cover 15. Figure 6 and 7 Furthermore, the fixing device 8 includes a nut 17, which is disposed at the sprocket cover 15 and used to secure the sprocket cover 15 to the housing 2. In a preferred embodiment, the nut 17 is constructed as a wing nut. The wings of the nut 17 are pivotable and can be pivoted out for rotating the nut 17. Thus, the operator of the motorized chainsaw 1 can operate the fixing device 8 without tools, i.e. without additional tools.

[0038] like Figure 2As shown, the motorized chainsaw 1 includes a bolt 19 having two threaded sections in this embodiment, spaced apart by a surrounding flange 38. The threaded section of the bolt 19 facing the housing 2 is screwed into the housing 2. A guide rail 5 is fixed to the outwardly extending threaded section of the bolt 19. For this purpose, a receiving opening 24 is provided on the guide rail 5 through which the bolt 19 extends. In this embodiment, the receiving opening 24 is configured as an elongated hole opening to one side. The guide rail 5 is clamped between a clamping element 16 and a contact surface 39 by a nut 17. The contact surface 39 is formed at the flange 38 of the bolt 19. The nut 17 is screwed onto the bolt 19 and presses the clamping element 16 against the guide rail 5, which in turn abuts against the contact surface 39 of the bolt 19. In an alternative embodiment of the tool 1, it is suitable that the contact surface 39 is not provided at the flange 38 of the bolt 19, but is provided directly on the housing 2 of the tool 1.

[0039] like Figure 6 and 7 As shown, the clamping element 16 includes a support ring 27, a contact ring 25, and a spring unit 18 disposed between the support ring 27 and the contact ring 25. In this embodiment, the spring unit 18 consists of a plurality of disc springs arranged in a row. The clamping element 16 rests against the end face of the nut 17 with the support ring 27, wherein the spring unit 18 presses the contact ring 25 against the guide rail with its clamping surface 26. Thus, the clamping surface 26 of the clamping element 16 is pre-tightened against the guide rail 5. The clamping element 16 generates a clamping force, which is used to hold the guide rail 5 at the housing 2, particularly between the contact surface 39 of the bolt 19 and the clamping surface 26 of the clamping element 16.

[0040] like Figure 2 As shown, a tensioning device 10 is provided for pre-tensioning the saw chain 7. By means of the tensioning device 10, the guide rail 5 moves forward away from the drive sprocket 4 along its longitudinal axis 6. The tensioning device 10 includes a spring element 14 that acts on the guide rail 5 with a spring force along the longitudinal axis 6 away from the drive sprocket 4. Figure 12 As shown, spring element 14 is supported at one end of housing 2. The other end of spring element 14 engages with a spring opening 33 provided in guide rail 5. In this embodiment, spring element 14 is constructed as a leaf spring. In an alternative configuration, tensioning device 10 can also be designed via a different spring system. Tensioning device 10 operates such that, in the event of release of fixing device 8, guide rail 5 is tensioned away from drive sprocket 4 by spring force via spring element 14 along longitudinal axis 6. Thus, saw chain 7 is pre-tensioned using tension force. The tension force corresponds to the spring force of spring element 14. Therefore, tensioning device 10 achieves targeted and reproducible pre-tensioning of saw chain 7 without direct operator intervention.

[0041] like Figure 2 As shown, a recess 34 is provided at the guide rail 5, and the protrusion 28 of the housing 2 extends into the recess. The recess 34 of the guide rail 5 is constructed to be open. The protrusion 28 of the housing 2 forms a stop portion of the guide rail 5 along the longitudinal axis 6. At the same time, the guide rail 5 is guided parallel to the longitudinal axis 6 of the guide rail 5 by the protrusion 28 at the recess 34.

[0042] like Figure 2 China and Figures 8 to 11 As shown, the motorized chainsaw 1 includes a chain lifting device 11. The chain lifting device 11 includes an offset element 12, which in a preferred embodiment is constructed as a saddle-shaped element. In an alternative embodiment, the offset element 12 may also be a magnet, particularly an electromagnet. In this embodiment, the offset element 12 is constructed as a single piece with the guide rail 5. The offset element 12 is constructed at the guide rail 5 such that it extends into the guide groove 21 of the guide rail 5 as a spring element in a clamped state. Figure 6 As shown in 7 and 8 to 11, the guide rail 5 is composed of the first side element 42 ( Figure 8 ), second side element 48 ( Figure 9 ) and intermediate element 43 arranged between first side element 42 and second side element 48 Figure 10 The offset element 12 is constructed at the intermediate element 43, particularly as a single piece. The offset element 12 is formed by a partial punched portion at the intermediate element 43, wherein the punched portion of the offset element 12 is connected to the intermediate element via a bridging member 44. The offset element 12 is spring-loaded. Thus, the offset element 12 can move laterally along the longitudinal plane 29 extending from the guide rail 5, particularly pivoting. Figure 6 As shown, in this embodiment, the offset element 12 is configured such that it engages in the guide groove 21 of the guide rail 5 on the lower side 45. The guide rail 5 includes a lower side 45 and an upper side 46. On the upper side 46 of the guide rail 5, the saw chain 7 extends away from the drive sprocket 4, and on the lower side 45 of the guide rail 5, the saw chain 7 extends towards the drive sprocket 4. At the lower side 45, a descent of the saw chain 7 is formed due to gravity. This ensures that, in the normal operating posture of the motorized chainsaw 1, the offset element 12 engages between the saw chain 7 and the groove bottom 22 when it is switched to the offset position 40. Otherwise, the offset element 12 would pivot laterally toward the saw chain, thereby no longer achieving the offset of the saw chain 7 away from the groove bottom 22 according to this embodiment.

[0043] like Figure 6 and 7As shown, the motorized chainsaw 1 includes an adjusting element 13. The adjusting element 13 is operatively connected to the offset element 12, preferably directly, depending on the position of the fixing device 8. If the fixing device 8 is in the fixed position 30, the offset element 12 is pushed out of the guide groove 21 of the guide rail 5 by the adjusting element 13. If the fixing device 8 is in the loose or partially loose positions 31, 32, there is no operative connection between the adjusting element 13 and the offset element 12. The offset element 12 is then located in the guide groove 21 of the guide rail 5. In this embodiment, the adjusting element 13 is arranged at the sprocket cover 15, preferably constructed as a single piece with the sprocket cover 15. The adjusting element 13 is constructed as a pin. The adjusting element 13 moves by manipulating the fixing device 8 in the longitudinal plane 29 of the guide rail 5. If the guide rail 5 is fixed by means of the fixing device 8, the sprocket cover 15, together with the adjusting element 13, moves towards the housing 2 via the nut 17. Here, the adjusting element 13 presses the offset element 12 out of the guide groove 21 of the guide rail 5. If the fixing device 8 comes loose again, the adjusting element 13 moves back, thereby causing the offset element 12 to pivot back into the guide groove 21 of the guide rail 5.

[0044] The tensioning process of saw chain 7 and the combined function of the various components of motorized chainsaw 1 are described below:

[0045] To retighten saw chain 7, nut 17 should be loosened from sprocket cover 15. Fixing device 8 is then removed from its fixed position 30. Figure 7 ) shifted to a partially loosened position 31 ( Figure 5 and 6 In this position, the sprocket cover 15, along with the adjusting element 13, moves away from the housing 2, so that the adjusting element 13 no longer acts on the offset element 12. The offset element 12 of the chain lifting device 11 pivots into the guide groove 21 of the guide rail 5. Figure 5 ).like Figure 3 As shown in Figures 5 and 6, the chain lifting device is located in offset position 40. Therefore, the offset element 12 is located between the drive link 23 of the saw chain 7 and the bottom 22 of the groove in the guide rail 5. The offset element 12, with its abutting surface for the saw chain 7, is positioned between the bottom 22 of the groove in the guide rail 5 and the guide rail 20. Therefore, the offset element 12 extends beyond the bottom 22 of the groove and is below the guide rail 20 of the guide rail 5.

[0046] In the partially detached position 31 of the fixing device 8, the guide rail 5 remains clamped between the clamping element 16 and the housing 2. The preload of the clamping element 16, generated by the spring unit 18 of the clamping element 16, is designed such that the clamping force between the clamping element 16 and the guide rail 5 is high enough to secure the guide rail 5. Therefore, not only in the partially detached position of the fixing device 8 but also in its fixed positions 31 and 30, the clamping force is higher than the tension force of the spring element 14 of the tensioning device 10.

[0047] In the next step, the fixing device 8 is further loosened until it is in the loosened position 32. Figure 3 The preload of clamping element 16 is reduced such that the tensioning force of tensioning device 10 is higher than the clamping force of clamping element 16. As a result, guide rail 5 moves away from drive sprocket 4 in the direction of leading longitudinal axis 6 via tensioning device 10, particularly via spring element 14. Saw chain 7 is tensioned. Saw chain 7 rests against offset element 12. Thus, saw chain 7 is maintained at a predetermined distance relative to guide rail 5's guide rail 20 in the offset position 40 of chain lifting device 11 and the loosened position 32 of fixing device 8. In this state, saw chain 7 rests against offset element 12 with its transmission link 23. Saw chain 7 is lifted outward from guide rail 5's guide rail 20 in a direction away from the groove bottom 22 of guide rail 5 by offset element 12. At such a point in time, i.e., when saw chain 7 is offset by offset element 12 and therefore requires a longer saw chain 7 to tightly surround guide rail 5, the tensioning force of tensioning device 10 applies maximum chain tension to saw chain 7.

[0048] In a further step, the fixing device 8 is tightened again by the nut 17 to the partially loosened position 31. This achieves: increasing the preload of the clamping element 16, and ensuring that the clamping force between the clamping element 16 and the guide rail 5 is greater than the tension of the tensioning device 10. The guide rail 5 is fixed. Then, by further rotating the nut 17, the sprocket cover 15, together with the adjusting element 13, is moved toward the housing 2 such that the adjusting element 13 acts on the chain lifting device 11, and the offset element 12 is moved out of the guide groove 21. Figure 4 Furthermore, the clamping force of the clamping element 16 is further increased until it reaches the final clamping force in the fixed position 30 of the fixing device 8.

[0049] In the fixed position 30 of the fixing device 8, the chain lifting device 11 is in the operating position 41. The saw chain 7 is no longer lifted by the offset element 12, thereby achieving a predetermined distance relative to the guide rail 20 or a predetermined chain gap of the saw chain 7. Since the offset element 12 no longer offsets the saw chain 7, a shorter saw chain 7 is required to tightly surround the guide rail 5, thereby freeing the saw chain 7 of a limited length and reducing the chain tension compared to the maximum chain tension. The defined chain gap is set by the defined length difference. Here, the fixing device 8 and the chain lifting device 11 are coordinated with each other so that the targeted chain gap of the saw chain is small enough to prevent the saw chain from detaching from the guide rail 5. In addition, the chain gap is large enough to prevent the saw chain 7 from getting stuck at the guide rail 5.

[0050] When tensioning the saw chain 7, it is important that the offset element 12 contacts the saw chain 7 on the inside of the guide rail 5 so that the saw chain 7 can be offset away from the bottom 21 of the groove in the guide rail 5. Therefore, the motorized chainsaw 1 according to the invention provides a two-stage tensioning process for the saw chain 7. While the saw chain 7 is not tensioned, the offset element 12 engages in the guide groove 21. This ensures that the offset element 12 contacts the saw chain 7 on the inside of the saw chain. Only then is the saw chain 7 tensioned.

Claims

1. A motorized chainsaw, the motorized chainsaw having a housing (2) and a drive motor (3), wherein, The drive motor (3) drives the saw chain (7) guided in the guide groove (21) of the guide rail (5) around the drive sprocket (4), wherein the guide rail (5) has a longitudinal plane (29) extending from the guide groove (21), wherein the guide rail (5) is held in the housing (2) by a releasable fixing device (8) and is movable relative to the housing (2) along the longitudinal axis (6) of the guide rail via a tensioning device (10) when the fixing device (8) is released, characterized in that the motorized chainsaw (1 The device includes a chain lifting device (11) separately constructed from the tensioning device (10), and the chain lifting device (11) is configured to deflect the saw chain (7) in an offset position (40) of the chain lifting device (11) when the tensioning device (10) tensions the saw chain (7), and to slack the saw chain (7) in an operating position (41) of the chain lifting device (11) when the guide rail (5) is fixed, wherein the chain lifting device (11) includes an offset element (12) acting on the saw chain (7).

2. The motorized chainsaw according to claim 1, characterized in that, The guide rail (5) forms a guide rail (20) for the saw chain (7), wherein the offset element (12) lifts the saw chain (7) from the guide rail (20) a predetermined distance at the offset position (40) of the chain lifting device (11).

3. The motorized chainsaw according to claim 1, characterized in that, The saw chain (7) is abutted against the offset element (12) of the chain lifting device (11) at the offset position (40).

4. The motorized chainsaw according to claim 1, characterized in that, The offset element (12) of the chain lifting device (11) is capable of moving laterally relative to the longitudinal plane (29).

5. The motorized chainsaw according to claim 1, characterized in that, The offset element (12) of the chain lifting device (11) is pivotally supported relative to the guide groove (21).

6. The motorized chainsaw according to claim 1, characterized in that, The offset element (12) extends into the guide groove (21) of the guide rail (5) at the offset position (40), and the transmission link (23) of the saw chain (7) is lifted away from the bottom (22) of the groove of the guide rail (5).

7. The motorized chainsaw according to claim 1, characterized in that, The offset element (12) is arranged on the lower side (45) of the guide rail (5), wherein the saw chain (7) extends toward the drive sprocket (4) at the lower side (45) of the guide rail (5).

8. The motorized chainsaw according to claim 1, characterized in that, An adjustment element (13) is provided for moving the offset element (12).

9. The motorized chainsaw according to claim 8, characterized in that, In the operating position (41) of the chain lifting device (11), the adjusting element (13) acts on the offset element (12).

10. The motorized chainsaw according to claim 1, characterized in that, The offset element (12) and the guide rail (5) are constructed as a single piece.

11. The motorized chainsaw according to claim 1, characterized in that, The fixing device (8) acts on the chain lifting device (11) such that the chain lifting device (11) is located in the running position (41) in the fixed position (30) of the fixing device (8).

12. The motorized chainsaw according to claim 1, characterized in that, The fixing device (8) and the chain lifting device (11) are coordinated with each other such that the guide rail (5) is tensioned by the tensioning device (10) when the fixing device (8) is released, and the chain lifting device (11) is located in the offset position (40).

13. The motorized chainsaw according to claim 1, characterized in that, The tensioning device (10) includes a spring element (14) that pre-tensions the guide rail (5) away from the housing (2) along the longitudinal axis (6) of the guide rail (5).

14. The motorized chainsaw according to claim 1, characterized in that, The fixing device (8) and the chain lifting device (11) are coordinated with each other such that the fixing device (8) holds the guide rail (5) in the partially loosened position (31) and the chain lifting device (11) is in the offset position (40).

15. The motorized chainsaw according to claim 1, characterized in that, The fixing device (8) includes a sprocket cover (15) and a clamping element (16) disposed on the sprocket cover (15), wherein the guide rail (5) is pressed against the housing (2) via the clamping element (16).

16. The motorized chainsaw according to claim 15, characterized in that, The fixing device (8) includes a spring unit (18), wherein the clamping element (16) is supported on the sprocket cover (15) transverse to the longitudinal plane (29) of the guide rail (5) via the spring unit (18).

17. The motorized chainsaw according to claim 15, characterized in that, In the fixed position (30) of the fixing device (8) and in the partially loosened position (31) of the fixing device, the clamping force exerted by the clamping element (16) on the guide rail (5) is greater than the tensioning force exerted by the tensioning device (10) on the guide rail (5).

18. A method for tensioning a saw chain in a motorized chainsaw, wherein, The motorized chainsaw (1) includes a housing (2) and a drive motor (3), wherein the drive motor (3) drives a saw chain (7) guided on a guide rail (5) via a drive sprocket (4), wherein the guide rail (5) is held in the housing (2) via a releasable fixing device (8) and is movable relative to the housing (2) via a tensioning device (10) along the longitudinal axis (6) of the guide rail when the fixing device (8) is released, characterized in that the chain lifting device (11) of the motorized chainsaw causes the saw chain (7) to deflect in an offset position (40) of the chain lifting device (11) when the tensioning device (10) tensions the saw chain (7), and causes the saw chain (7) to slack in an operating position (41) of the chain lifting device (11) when the guide rail (5) is fixed.

Images