HAND-HELD TOOL WITH ONE GUIDE RAIL

Description

[0001] The invention relates to a hand-held working device with a guide rail of the type specified in the preamble of claim 1.

[0002] DE 196 19 081 A1 discloses a hand-held tool, namely a pole pruner. The pole pruner has a cutting head to which a guide bar is attached. An oil pump is provided to lubricate the saw chain rotating along the guide bar. This pump feeds oil from an oil tank through an oil channel to an oil groove in a mounting flange. A guide bar rests against the mounting flange during operation. Relative to the tool's normal working position, the mounting flange is located on the right side of the cutting head. This obstructs the view of the cutting point during operation due to the cutting head.

[0003] The outer side of the guide bar adjacent to the mounting flange typically has an oil supply opening opposite the oil groove of the mounting flange and extending from the outer side into the guide groove. Oil is supplied through the oil supply opening into the guide groove of the guide bar. To enable the guide bar to be turned, oil supply openings are usually located on both outer sides of the guide bar. The oil supply occurs exclusively via the oil supply opening located on the side facing the mounting flange. The oil-supplying oil supply opening is typically located above a longitudinal center axis of the guide bar, so that oil is transported with the saw chain towards the tip of the guide bar.

[0004] In order to improve the view of the guide rail during operation, it is desirable that the mounting flange for the guide rail is located on the left side of the cutting head during normal operation, so that the cutting head only slightly obscures the view of the guide rail in the normal working position.

[0005] On conventional chainsaws, the guide bar stop surface is located on the right side of the chainsaw. The guide bar has an oil supply opening on the outside, where it rests against the chainsaw housing, for supplying oil to the guide groove. It is desirable that the guide bars of conventional chainsaws can also be used for tools where the guide bar stop surface is located on the opposite, left-hand side, and that the oil supply can be provided via the same oil supply opening.

[0006] A tool of this type is known from DE 195 47 353 A1. The guide rail has an oil supply channel fed by a transverse channel. The transverse channel can extend from one outer side of the guide rail to the other. The transverse channel and oil supply channel are formed in an insert part of the guide rail, which is fixed in the base body of the guide rail.

[0007] The invention is based on the object of creating a hand-held working device of the generic type on which guide rails can be mounted, in which an oil supply opening is arranged on the side facing away from the housing of the working device.

[0008] This object is achieved by a working device having the features of claim 1.

[0009] It is provided that the oil supply channel, which connects the oil supply opening in the guide bar to an oil supply device, comprises a channel section which is formed separately from the guide bar and extends at least from a first plane, which comprises the outer side of the guide bar facing the housing, to a second plane, which comprises the outer side of the guide bar facing the sprocket cover. The channel section therefore extends at least across the width of the guide rail between the housing and the sprocket cover. Because the channel section is formed separately from the guide rail, the channel section can be arranged stationary relative to the housing. As a result, the channel section does not move when the saw chain is tensioned and, for this purpose, the guide bar is moved relative to the housing and relative to the sprocket cover. This simplifies the sealing of the channel section.The channel section is decoupled from any relative movement of the guide bar with respect to the housing. Via the channel section, oil can be easily fed from the housing to the side of the guide bar facing the sprocket cover and from there via the oil feed opening into the guide groove of the guide bar. This makes it easy to lubricate the saw chain. Guide bars can be used in which the oil feed opening is located on the side facing away from the housing. Despite the changed position of the mounting flange, the oil is supplied via the oil feed opening of the guide bar, which is also how the oil would be supplied if the mounting flange were in the conventional position.

[0010] A preferred arrangement of the channel section occurs when the longitudinal center axis of the guide rail intersects the channel section. The channel section is therefore arranged in the region of the longitudinal center axis of the guide rail. Particularly preferably, the channel section extends through a guide slot in the guide rail. This achieves a compact arrangement with short paths for the oil, thus ensuring reliable lubrication.

[0011] A simple design is achieved if the channel section is at least partially formed in an extension that projects into a receptacle. The oil supply channel runs through the receptacle. When the sprocket cover is removed from the housing, the extension is advantageously pulled out of the receptacle. This allows the sprocket cover to be easily removed from the housing, whereby the oil supply channel between the oil supply device and the oil supply opening of the guide rail is separated. By inserting an extension into a receptacle, a separable connection in the oil supply channel can be easily achieved. The extension and the receptacle are advantageously sealed to one another at a seal. The seal can be formed on a separate sealing element arranged between the extension and the receptacle.Particularly preferably, the seal is designed as a sealing surface that is formed directly between the extension and the receptacle, and at which the receptacle and extension abut one another. The seal is preferably arranged on the circumference of the extension. The seal is thus a seal that acts in the radial direction. This allows a secure seal to be achieved, in particular over a comparatively large sealing surface. Due to the circumferential seal, the sealing effect is largely independent of the relative position of the extension and receptacle to one another, which, for example, varies with guide rails of different thicknesses.

[0012] A simple and reliable seal can be achieved if the seal is fixed relative to the housing when the guide bar is moved. This means that the seal does not move relative to the housing when the guide bar is moved, i.e., when the saw chain is tensioned. Because the extension and the retainer are pulled apart when the sprocket cover is removed, only one of the seal's sealing partners moves when the sprocket cover is put on or taken off.

[0013] To facilitate easy installation and removal of the sprocket cover, it is advantageously provided that the seal is arranged between the second level and an outer side of the sprocket cover facing away from the housing. A sealing partner or an element carrying a separate seal thus protrudes through the area between the first and second levels onto the side of the guide rail facing away from the housing when the guide rail is placed on the housing.

[0014] It can be provided that the receptacle is arranged on the housing and the extension on the sprocket cover. Even when arranged on the sprocket cover, the extension can extend to the first level on the housing or into the housing. However, it can also be advantageous for the receptacle to extend at least to the second level.

[0015] An arrangement in which both the receptacle and the extension extend into the area between the two levels can also be advantageous. Alternatively, the receptacle can be arranged on the sprocket cover and the extension on the housing. The extension can extend up to the second level on the sprocket cover or into the sprocket cover. Even when the receptacle is arranged on the sprocket cover, both the receptacle and the extension can extend into the area between the two levels.

[0016] The receptacle is advantageously a sleeve. The sleeve is in particular a metal sleeve. However, a plastic sleeve can also be advantageous. The extension is advantageously formed by a guide element. The channel section is preferably designed as a through-opening in the guide element. The guide element is in particular a guide pin. The extension is preferably attached to the housing and the sleeve to the sprocket cover. This allows a guide element to be used as the extension.

[0017] A simple oil supply to the side of the guide rail facing away from the housing is achieved if an oil supply slot is formed in the sprocket cover, which is arranged opposite the oil supply opening of the guide rail. The oil supply slot advantageously extends over a length that corresponds at least to the usual adjustment path of a guide rail relative to the housing. This ensures that oil is supplied from the oil supply slot into the oil supply opening of the guide rail in any position of the guide rail. Because the channel section is formed separately from the guide rail and advantageously does not move with the guide rail, the oil supply slot is preferably the only point in the oil supply channel whose sealing surfaces move relative to one another when the position of the guide rail relative to the housing is adjusted.It may be advantageous to completely close the oil supply channel over all other areas over their entire circumference, resulting in a closed channel. However, a simpler structure is achieved if the channel section is connected to the oil supply slot via a connecting channel open to the rail contact surface of the sprocket cover. Such a connecting channel can be easily integrated in the form of a groove on the sprocket cover, particularly during the production of the sprocket cover using an injection molding process. The connecting channel is sealed via the outer side of the guide rail facing the sprocket cover.

[0018] The work tool advantageously has a tensioning device. The tensioning device serves in particular for tensioning the saw chain. The guide bar has a transverse plane that contains the longitudinal center axis of the guide bar and is perpendicular to the plane of the guide bar. The oil feed slot and the tensioning device are preferably arranged on opposite sides of the transverse plane. This results in a compact design. The oil feed slot is preferably arranged in the region of the upper run of the saw chain running to the free end of the guide bar, and the tensioning device is arranged in the region of the lower run of the saw chain running from the free end of the guide bar to a drive pinion. The oil feed opening, at which the oil feed channel ends, is also advantageously arranged in the region of the upper run of the saw chain.

[0019] Advantageously, at least two guide elements are provided for the guide bar. A second guide element is advantageously designed as a guide bolt and has an external thread for screwing on a fastening nut to fix the sprocket cover. The second guide element is advantageously longer than the first guide element, which forms the extension. The length of the guide elements is measured perpendicular to the first plane and up to the first plane. The implement is advantageously a pole pruner and the housing a gearbox housing. The implement is preferably a implement in which the support surface of the housing, against which the guide bar rests, is arranged on the left side of the housing in the normal operating position, in which the saw chain runs on the upper run to the free end and on the lower run to the drive pinion, when viewed from the housing to the free end.

[0020] Preferably, the housing and the extension are separately formed components that are firmly connected to one another. The housing and extension can advantageously be made of different materials. The extension is, in particular, interchangeable. The separate design of the housing and extension is particularly advantageous if the extension forms a guide element for the guide rail. In an alternative design, however, it may also be advantageous to form the extension as a single piece with the housing or the sprocket cover. A single-piece design as an injection-molded component is particularly advantageous.

[0021] Embodiments of the invention are explained below with reference to the drawings. They show: Fig. 1 a partially schematic, perspective view of a pole pruner, Fig. 2 a top view of a cutting head of the pole pruner, Fig. 3 a side view in the direction of arrow III in Fig. 2 , Fig. 4 a partially sectioned side view in the direction of arrow IV in Fig. 3 , Fig. 5 a partially sectioned side view in the direction of arrow V in Fig. 4 , Fig. 6 a section through the cutting head along the line VI-VI in Fig. 5 , Fig. 7 a side view of the housing of the cutting head with the guide rail arranged thereon, Fig. 8 a side view of the sprocket cover from the side facing the housing, Fig. 9 a section along the line IX-IX in Fig. 8 , Fig. 10 a section along the line XX in Fig. 8 , Fig. 11 a partially sectioned view of the cutting head in the area of ​​the guide rail, Fig. 12 a side view of the housing of the cutting head, Fig. 13 a side view in the direction of arrow XIII in Fig. 12 , Fig. 14 a partially sectioned side view in the direction of arrow XIV in Fig. 13 , Fig. 15 a partially sectioned side view in the direction of arrow XV in Fig. 14 , Fig. 16 and 17 schematic partial sectional views of embodiments of the channel section, Fig. 18 a schematic partially sectional view of an embodiment of a sprocket cover, Fig. 19 a schematic sectional view of the sprocket cover from Fig. 18 , Fig. 20 a schematic side view of an embodiment of a gear housing for the Figuren 18 und 19 shown sprocket cover, Fig. 21 a schematic partially sectioned side view in the direction of arrow XXI in Fig. 20 .

[0022] Fig. 1 shows a pole pruner 1 as an exemplary embodiment of a hand-held tool. However, the hand-held tool can also be another hand-held tool with a guide rail, for example a chainsaw. The pole pruner 1 has a drive unit 2, which is connected to a cutting head 14 via a guide tube 5. The drive unit 2 has a housing 3 in which a Fig. 1 A schematically illustrated drive motor 4 is arranged. The drive motor 4 is advantageously an internal combustion engine. However, the drive motor 4 can also be an electric motor. It can also be provided that the drive motor is arranged on the cutting head 14, in particular if the drive motor 4 is an electric motor. A rechargeable battery for supplying the drive motor 4 with energy can then be arranged in the housing 3 of the drive unit 2, for example.

[0023] The guide tube 5 has a first end 12, to which the drive unit 2 is attached. Adjacent to the first end 12, a handle 6 is attached to the guide tube 5, on which a throttle lever 7 and a throttle lock 8 are mounted. Additional or other control elements may also be advantageous.

[0024] In the exemplary embodiment, the guide tube 5 is designed as a telescopic tube and has a first, outer section 9 into which a second, inner section 10 extends. The two sections 9 and 10 are connected to one another via a fixing device 11. However, the guide tube 5 can also be designed as a tube whose length is not adjustable. A drive shaft advantageously extends through the guide tube 5. The guide tube 5 has a second end 13, which is formed on the second, inner section 10 of the guide tube 5 and to which the cutting head 14 is fixed.

[0025] The cutting head 14 has an oil tank 15, which can be opened and closed with an oil tank cap 16. A guide rail 17 is arranged on the cutting head 14, on which a saw chain 18 is guided. The saw chain 18 is driven in rotation on the guide rail 17 by the drive motor 4. The guide rail 17 has a longitudinal center axis 61 and a transverse plane 63. The transverse plane 63 is perpendicular to the plane of the guide rail 17 and contains the longitudinal center axis 61. The saw chain 18 therefore only intersects the transverse plane 63 at the free end of the guide rail 17 and when passing a chain wheel 55 ( Fig. 6 ) and does not lie over its entire length in the transverse plane 63.

[0026] In the normal working position, the tool is positioned to the right of the operator. To ensure that the gearbox housing does not obstruct the view of the cutting area during operation, the guide rail 17 is positioned on the left side of the cutting head 14, as seen from the operator's perspective.

[0027] The Fig. 2 und 3 show the structure of the cutting head 14. How Fig. 2 shows, the cutting head 14 has a fastening socket 24 with which the cutting head 14 can be clamped onto the guide tube 5 by means of screws 25. As Fig. 3 shows, the fastening socket 24 has a longitudinal slot 26 which allows elastic deformation of the fastening socket 24.

[0028] How Fig. 2 shows, the cutting head 14 has a gear housing 19 on which the oil tank 15 is arranged. A sprocket cover 20 is fixed to the gear housing 19 via a fastening element, in the exemplary embodiment a fastening nut 21. As Fig. 3 shows, the fastening nut 21 is screwed onto a guide pin 28 of the gear housing 19. Adjacent to the fastening nut 21, an opening is provided in the chain wheel cover through which a tensioning screw 22 of a tensioning device for the saw chain 18, which will be described in more detail below, can be actuated. Furthermore, a hook 23 is formed on the gear housing 19, which can prevent the cutting head 14 from slipping during operation. The hook 23 is also in Fig. 4 shown.

[0029] During operation, the saw chain 18, namely the strand of the saw chain 18 running from the cutting head 14 to the free end of the guide bar 17 ( Fig. 1 ) oil. In the normal operating position, the strand running from the cutting head 14 to the free end of the guide bar 17 is the upper strand of the saw chain 18. For the oil supply, an oil supply device is provided in the gear housing 19, in the exemplary embodiment a Fig. 6 shown oil pump 79, which supplies oil from the oil tank 15 via an oil supply channel 60 to the guide rail 17 ( Fig. 1 ). The guide rail 17 is in Fig. 4 not shown. In Fig. 4 However, a first plane 68 is schematically shown, in which a first outer side 58 ( Fig. 11 ) of the guide rail 17. In addition, a second plane 69 is shown schematically. In the second plane 69 there is a Fig. 11 shown second outer side 59 of the guide rail 17. Centrally between the outer sides 58 and 59 there is a guide groove 57 in which the saw chain 18 ( Fig. 1 ) is carried out.

[0030] Fig. 4 shows a part of the oil supply channel 60. The oil supply channel 60 refers to the entire oil supply channel from the oil pump 79 ( Fig. 6 ) to an oil supply opening in the guide rail 17. A section of the oil supply channel 60 is guided in a supply hose 32. The supply hose 32 has a constriction on its outer circumference, which in the exemplary embodiment is connected to an opening 33 in a wall of the gear housing 19. The supply hose 32 opens into an oil chamber 31, which is also formed in the gear housing 19. In the exemplary embodiment, a first guide pin 27 is pressed into the oil chamber 31. The guide pin 27 forms an extension protruding from the gear housing 19. The guide pin 27 can be made of a different material than the gear housing 19. It can be advantageous for the guide pin 27 to be held interchangeably on the gear housing 19. The guide pin 28, onto which the fastening nut 21 is screwed ( Fig. 3 ), forms a second guide pin. The first guide pin 27 has a through-opening which forms a channel section 29 of the oil supply channel 60. The free end of the first guide pin 27 protruding from the gear housing 19 is inserted into a sleeve 30 which is held in the sprocket cover 20. The sleeve 30 is also provided with a through-opening. The channel section 29 opens into an oil chamber 37 formed in the sprocket cover 20, from which oil chamber 37 a connecting channel 38 leads. The connecting channel 38 will be described in more detail below. The oil chamber 37 and the connecting channel 38 also form sections of the oil supply channel 60. The guide pin 27 forms an extension, and the sleeve 30 forms a receptacle.

[0031] How Fig. 4 As shown, the guide pin 27 has an outwardly projecting collar 34, which rests against a stop 35 formed on the gear housing 19. This design determines the insertion depth of the guide pin 27. The sleeve 30 has, adjacent to the second plane 69, i.e., on its side facing the guide rail 17, an outwardly projecting collar 36, which limits the insertion depth of the sleeve 30 into the sprocket cover 20 and ensures that the sleeve 30 cannot close the connecting channel 38 beginning at the circumference of the oil chamber 37. As Fig. 4 As also shown, a gap 70 is formed between the planes 68 and 69, through which the guide rail 17 can protrude from the cutting head 14. The gap 70 extends only over part of the circumference of the cutting head 14.

[0032] As in Fig. 5 As shown, a seal 64 is formed between the sleeve 30 and the first guide pin 27. The seal 64 extends in the longitudinal direction and in the circumferential direction of a longitudinal axis 80 of the channel section 29. In the exemplary embodiment, the seal 64 is formed on a sealing surface against which the sleeve 30 rests with its inner contour against the outer contour of the guide pin 27. The sealing surface is cylindrical and arranged on the circumference of the guide pin 27. Because the seal 64 is a seal that acts in the circumferential direction and not on the end face, reliable sealing can be achieved with different positions of the sprocket cover 20, for example when guide rails 17 of different thicknesses are arranged between the gear housing 19 and the sprocket cover 20. Sealing of the channel section 29 is achieved in a simple manner via the seal 64.

[0033] How Fig. 5 shows, the seal 64 is arranged entirely between the second plane 69 and an outer side 65 of the sprocket cover 20 facing away from the gear housing 19. The seal 64 is therefore located entirely within the width of the sprocket cover 20. The first guide pin 27 is held firmly on the gear housing 19, and the sleeve 30 is held firmly on the sprocket cover 20. If the guide rail 17 is displaced relative to the gear housing 19 and the sprocket cover 20, in particular for tensioning the saw chain 18, the seal 64 does not move relative to the gear housing 19 and the sprocket cover 20. Also, there is no movement in the sealing surface, i.e., movement between the sleeve 30 and the guide pin 27. When removing the chain wheel cover 20, in particular to replace the guide bar 17 and / or the saw chain 18, the fastening nut 21 is loosened and the chain wheel cover 20 is removed from the gear housing 19 in the direction of arrow 90.The holder 30 is pulled off the first guide pin 27. The guide pin 27 is then pulled out of the holder 30.

[0034] How Fig. 6 shows, a drive element 71 is arranged in the fastening socket 24, which has a drive contour 72 on its inner circumference. The drive contour 72 is, in the exemplary embodiment, a square cross-section, via which the drive torque of the drive motor 4 ( Fig. 1 ) is transmitted from a drive shaft (not shown) to the drive element 71. The drive element 71 is rotatably mounted in an inner housing 66 arranged in the gear housing 19 by bearings 73, in the exemplary embodiment roller bearings. The inner housing 66 is advantageously sealed from the environment, and the interior 67 of the inner housing 66 is filled with grease or oil. For sealing, the bearings 73 are provided with sealing washers. A drive bevel gear 75 of an angular gear 74 is fixed to the drive element 71. The drive element 71 with the drive bevel gear 75 is rotatable about a rotational axis 91, which in the exemplary embodiment coincides with the longitudinal center axis of the guide tube 5 ( Fig. 1 ) coincides. The cutting head 14 has a chain wheel 55 which drives the saw chain 18 ( Fig. 1 ). The sprocket 55 is rotatable about a rotational axis 56, which is arranged transversely, in the exemplary embodiment perpendicularly, to the rotational axis 91 of the drive element 71. The sprocket 55 is fixed to an output shaft 77, which is mounted in the inner housing 66 by bearings 78. The bearings 78 also have sealing disks. On the side projecting into the inner housing 66, the output shaft 77 carries an output bevel gear 76, which meshes with the input bevel gear 75 and together with it forms the bevel gear 74.

[0035] The oil pump 79 is also located in the inner housing 66. The oil pump 79 is driven by a drive worm gear 81, which carries a worm gear toothing 88. The worm gear toothing 88 meshes with an oil pump pinion toothing 89 of an oil pump pinion 82. The drive element 71 has a through-opening that has the drive contour 72. This simplifies production. The drive worm gear 81 has a connecting piece 85, which is inserted into the opening of the drive element 71 on one side and seals the interior 67 from the interior of the guide tube 5. As Fig. 6 As shown, the drive worm gear 81 is mounted on a floating support, i.e., it is supported on only one side, namely on the drive element 71. This results in a simple construction.

[0036] In the exemplary embodiment, the drive worm gear 81 has a through-hole 86 into which a pin 87, a metal pin in the exemplary embodiment, is inserted. The pressure between the drive element 71 and the drive worm gear 81 can be increased via the pin 87.

[0037] How Fig. 6 also shows, a suction hose 83 extends into the oil tank 15, at the free end of which a suction head 84 is fixed. The suction hose 83 supplies oil from the oil tank 15 to the oil pump 79. The suction hose 83 can be designed as a one-piece hose. However, it can be advantageous to provide several hose sections that are connected to one another, in particular on a wall of the oil tank 15. The oil pump 79 forms the oil supply device of the cutting head 14. The oil supply channel 60 leads from the oil pump 79 to the guide rail 17. A section of the oil supply channel 60 is shown in the Fig. 6 shown supply hose 32, which opens into the oil chamber 31.

[0038] Via the channel section 29, the oil is conveyed from the oil chamber 31 to the side of the chain wheel cover 20, i.e. to the second outer side 59 of a guide rail 17 ( Fig. 7 ), led.

[0039] Fig. 7 shows the guide rail 17 on the gear housing 19. The guide rail 17 has an oil supply opening 49 on the outer side 59 facing away from the gear housing 19, which extends as far as the guide groove 57. The oil supply opening 49 therefore does not extend over the entire width of the guide rail 17. A supply of oil from the side of the gear housing 19 is not possible. The oil supply opening 49 is arranged on the side of the transverse plane 63 on which the saw chain 18 ( Fig. 1 ) from the gear housing 19 to the free end of the guide rail 17. On both sides of the transverse plane 63, the guide rail 17 has clamping openings 51. On the side of the transverse plane 63 opposite the oil supply opening 49, a clamping bolt 48 projects into the clamping opening 51. The guide rail 17 has, at its end arranged on the gear housing 19, a guide slot 50 which extends in the direction of the longitudinal center axis 61 and in which a section of the longitudinal center axis 61 lies. In the exemplary embodiment, the guide slot 50 is open on the side facing the chain wheel 55. However, it can also be provided that the guide slot 50 is designed as a longitudinal slot closed at both ends. The first guide bolt 27 and the second guide bolt 28 project through the guide slot 50. The channel section 29 thus also projects through the guide slot 50.The guide slot 50 extends completely through the guide rail 50, i.e. over the entire thickness of the guide rail 17.

[0040] It may also be provided to arrange the channel section 29 outside the guide slot 50. Particularly preferably, the channel section 29 is arranged such that the longitudinal center axis 61 of the guide rail 17 intersects the channel section 29. However, an arrangement in a different area may also be advantageous. It may be particularly advantageous to arrange the channel section 29 in an area in which the sprocket cover 20 directly abuts the gear housing 19. This protects the channel section 29 during operation. This may, for example, be an edge area of ​​the gear housing 19 close to its outer contour.

[0041] The Fig. 8 bis 10 show the design of the sprocket cover 20 in detail. Fig. 8 shows the sprocket cover 20 from the side facing the gear housing 19 and the guide rail 17. The sprocket cover 20 has an opening 95 for the second guide pin 28. The sleeve 30 defines an opening 41 for the first guide pin 27. Between the openings 41 and 95 there is an opening 42 through which the clamping screw 22 ( Fig. 3 ) is accessible. The opening 41 is towards the outside 65 of the sprocket cover 20 ( Fig. 9 ) closed, as well as Fig. 9 The openings 92 and 95 are designed as through-openings and extend completely through the sprocket cover 20. An oil supply slot 39 is formed on the sprocket cover 20, which is parallel to the longitudinal center axis 61 of the guide rail 17 ( Fig. 7 ) and which is opposite to the oil supply opening 49 in the guide rail 17 ( Fig. 7 ) is arranged. The oil supply slot 39 forms the opening of the oil supply channel 60 on the guide rail 17, via which oil is introduced from the oil supply channel 60 into the oil supply opening 49 of the guide rail 17. Oil is supplied to the oil supply opening 49 via the oil supply slot 39. The oil supply slot 39 is connected to the oil chamber 37 at the bottom of the sleeve 30 via the connecting channel 38. The connecting channel 38 is also designed as a slot open towards the guide rail 17 and is sealed by the guide rail 17, thereby completing it to form a channel section that is completely closed on the circumference. At the opening 41, the oil chamber 37 is closed by the sleeve 30 except for a connecting opening at which the connecting channel 38 begins.

[0042] It may be advantageous to form the boundary contour of at least one cross-section of the oil supply channel 60 in sections in several parts. A particularly advantageous construction results if the section of the oil supply channel 60 formed in the chain wheel cover 20 is at least partially delimited on one side by the second outer side 59 of the guide rail 17. In the exemplary embodiment, the oil supply slot 39 and the connecting channel 38 are open towards a contact surface 93. During operation, the guide rail 17 rests against the contact surface 93 with its second outer side 59 ( Fig. 7 ) and seals the oil supply slot 39 and the connecting channel 38. Sealing surfaces that move relative to one another is relatively complex and prone to failure. The contact point between the oil supply slot 39 and the oil supply opening 49 is preferably the only point on the oil supply channel 60 whose sealing surfaces move relative to one another when the guide rail 17 moves. The channel section 29, on the other hand, is formed separately from the guide rail 17 and does not move with the guide rail 17, so that the channel section 29 can be sealed with a simple design and a reliable seal can be achieved.

[0043] In the exemplary embodiment, the contact surface 93 extends only between the oil supply slot and the openings 41, 42 and 95. The sprocket cover 20 has a plurality of contact ribs 40 on the side projecting towards the guide rail 17, the end faces of which also bear against the guide rail 17. This ensures uniform pressure of the sprocket cover 20 on the guide rail 17, resulting in good fixation. On the side of the opening 41 facing away from the opening 95, a rib 92 is provided, which also Fig. 9 The rib 92 extends close to the gear housing 19. As Fig. 6 shows, the rib 92 extends in the area between the sprocket 55 and the guide pins 27 and 28. The rib 92 is curved and extends adjacent to a portion of the circumference of the sprocket 55.

[0044] How Fig. 9 shows, the fastening nut 21 is held captively in the opening 95. For this purpose, a sleeve 45 is provided in the sprocket cover 20, which has an inwardly projecting retaining edge 46 on the side facing away from the gear housing 28. The fastening nut 21 has a sleeve-shaped sleeve section 43 projecting into the sprocket cover 20, at the end of which facing the gear housing 19, a retaining edge 44 is provided, at which the sleeve section 43 is bent outwards. The retaining edge 44 of the sleeve section 43 engages behind the retaining edge 46 of the sleeve 45 and thus prevents the fastening nut 21 from being removed from the sprocket cover 20. As Fig. 9 also shows, the fastening nut 21 has a collar 47 which rests on the outer side 65 of the chain wheel cover 20.

[0045] As the Fig. 8 bis 10 show, the sprocket cover 20 has a peripheral edge 94 adjacent to the sprocket 55, which extends to the gear housing 19. This is also shown in Fig. 6 shown. The peripheral edge 94 closes the gap 70 ( Fig. 4 ) over part of the circumference of the cutting head 14.

[0046] Fig. 11 shows the guide rail 17 between the gear housing 19 and the sprocket cover 20. How Fig. 11 As shown, the guide rail 17 has the oil supply opening 49 on its second outer side 59 facing the sprocket cover 20 and remote from the gear housing 19, which extends from the outer side 59 into the guide groove 57. The planes 68 and 69 have a distance c that corresponds to the thickness of the guide rail 17.

[0047] How Fig. 12 shows, the second guide bolt 28 has an external thread 62 onto which the fastening nut 21 ( Fig. 10 ) can be screwed on. As the Fig. 12 und 13 show, a support surface 54 for the guide rail 17 is formed on the gear housing 19. The support surface 54 is also comparatively small. In Fig. 13 The transverse plane 63 of the guide rail 17 is shown schematically. The transverse plane 63 extends through the longitudinal center axes of the guide pins 27 and 28. A clamping device 52 is arranged on one side of the transverse plane 63. The clamping device 52 has a clamping piece 53, which can be moved by turning the clamping screw 22 in the direction of the Fig. 11 shown longitudinal center axis 61 of the guide rail 17. The oil supply opening 49 ( Fig. 11 ) and the clamping device 52 are arranged essentially on opposite sides of the transverse plane 63. The support surface 54 formed on the gear housing 17 is adjacent to the oil supply opening 49, i.e. also arranged on the side of the transverse plane 63 opposite the clamping device 52. Adjacent to the support surface 54, the guide rail 17 has the Fig. 11 shown oil supply opening 49. A further oil supply opening is usually arranged adjacent to the clamping device 52, so that the guide rail 17 can be fixed to the gear housing 19 in two positions rotated about its longitudinal center axis 61. The further oil supply opening arranged adjacent to the clamping device 52 is in the running direction of the saw chain 18 ( Fig. 1 ) leading to the chain wheel 55 ( Fig. 12 ), so that an oil supply adjacent to the clamping device 52 is not practical. No oil is supplied via the additional oil supply opening during operation.

[0048] Fig. 14 shows the arrangement of the support surface 54 and the guide pins 27 and 28.

[0049] How Fig. 15 shows, the first guide pin 27 is significantly shorter than the second guide pin 28. The first guide pin 27 has a free length a projecting from the gear housing 19. The second guide pin 28 has a free length b projecting from the gear housing 19, which is significantly greater than the free length a. The free length b can be approximately 1.5 times to 3 times the free length a. The free lengths a and b are measured to the support surface 54 in the exemplary embodiment. In the exemplary embodiment, the guide pin 27 forms an extension. The free length a of the extension is advantageously greater than the Fig. 11 shown distance c between the planes 68 and 69. The distance c advantageously corresponds to the thickness of the guide rail 17. Advantageously, the free length a is at least the length of the seal 64, i.e. the sealing surface, measured in the direction of the longitudinal axis 80 ( Fig. 6 ) greater than the distance c ( Fig. 11 ). The free length b of the second guide pin 28 is advantageously dimensioned such that the second guide pin 28 extends completely through the chain wheel cover 20 to the outer side 65 of the chain wheel cover 20 ( Fig. 9 ) so that the fastening nut 21 can be easily fixed on the fastening bolt 28.

[0050] In Fig. 16 An embodiment of the gear housing 19 and sprocket cover 20 is shown, which essentially corresponds to the embodiment shown in the preceding figures. The same reference numerals denote corresponding elements in all figures. In the embodiment according to Fig. 16 A sleeve 110 is fixed to the gear housing 19. On the chain wheel cover 20, which in the schematic representation in Fig. 16 at a distance from the gear housing, an extension 107 is arranged. In the exemplary embodiment, the extension 107 is formed integrally with the sprocket cover 20. The extension 107 is advantageously formed onto the sprocket cover 20 using an injection molding process. The sleeve 110 serves to receive the extension 107, as in Fig. 16 is shown with a dotted line. The channel section 29 of the oil supply channel 60 extends through the sleeve 110 and the extension 107. Between the sleeve 110 and the extension 107, a Fig. 16 The seal 114 is shown schematically and is designed as a separate sealing element. However, the seal 114 can also be formed by a sealing surface on which the extension 107 and the sleeve 114 abut each other. As Fig. 16 shows, the seal 114 is arranged between the levels 68 and 69. When the guide rail 17 is mounted, the seal 114 is thus located between the outer sides 58 and 59 of the guide rail 17 ( Fig. 11 ). The seal 114 rests against the outer circumference of the extension 107 and the inner circumference of the sleeve 110.

[0051] In the Fig. 17 In the further exemplary embodiment shown, an extension 107 formed on the sprocket cover 20 projects beyond the plane 68 into the gear housing 19. The seal 114 is arranged in the gear housing 19, i.e. on the side of the plane 68 facing away from the plane 69. In a further alternative embodiment, it can also be provided that the sleeve 110 extends to the side of the plane 69 facing away from the gear housing 19. In particular, the seal 114 is arranged on the side of the plane 69 facing away from the gear housing 19.

[0052] The Figuren 18 bis 21 show another alternative design. At the Figuren 18 und 19 An extension 117 is arranged on the sprocket cover 20 shown. The position of the extension 117 is shown in Fig. 19 only shown schematically. The extension 117 is in an edge area of ​​the gear housing 19 outside the area in which the guide rail 17 ( Fig. 7 ) on the gear housing 19. The extension 117 can be designed as a separate component or molded onto the sprocket cover 20 and is connected to the oil supply slot 39 via a channel 118. The extension 117 extends to the side of the plane 68 facing away from the sprocket cover 20.

[0053] As the Figuren 20 und 21 show, a receptacle 120 is arranged in the gear housing 19 in the area opposite the extension 117, which is designed as a recess in the gear housing 19 and into which the extension 117 projects when the chain wheel cover 20 is fixed to the gear housing 19. The position of the extension 117 and the receptacle 120 is shown in the Figuren 18 bis 21 only shown schematically. The extension 117 and the receptacle 120 are advantageously arranged in an area which lies outside the guide rail 17 and has no contact with the saw chain 18 ( Fig. 1 ). The seal between the extension 117 and the sprocket cover 20 is advantageously arranged on the side of the plane 58 facing the gear housing 19 and can be designed as in one of the exemplary embodiments described above. However, it can also be advantageous for the seal to be arranged between the planes 68 and 69 or on the side of the plane 69 facing away from the plane 68. Instead of the recess in the gear housing 19, an extension of a corresponding length is then advantageously provided on the gear housing 19, which projects into a corresponding receptacle on the sprocket cover 20. The length of the extension is advantageously suitably adapted.

[0054] The illustrated embodiments can be combined with each other in any way to obtain advantageous designs. Designs of the embodiments according to the Figuren 16 bis 21 are advantageous as in the embodiment according to the Figuren 1 bis 15 trained.

Claims

1. Hand-held implement having a guide bar (17), wherein the guide bar (17) is held between a housing and a sprocket cover (20) of the implement, wherein the guide bar (17) has a guide groove (57) for a saw chain (18), wherein the guide bar (17) has a guide slot (50), which extends in the direction of a longitudinal centre axis (61) of the guide bar (17) and on which the guide bar (17) is guided in a longitudinally displaceable manner in relation to the housing by way of at least one guide element, wherein the guide bar (17) has a first outer side (58), which is directed towards the housing, and a second outer side (59), which is directed towards the sprocket cover (20), wherein the first outer side (58) is located in a first plane (68) and wherein the second outer side (59) is located in a second plane (69), wherein the implement has an oil-supply device, wherein the guide bar (17) has an oil-supply opening (49), which extends from the second outer side (59) of the guide bar (17) into the guide groove (57), wherein the oil-supply opening (49) is fluidically connected to the oil-supply device via an oil-supply channel (60), and wherein the oil-supply channel (60) comprises a channel portion (29) which extends at least from the first plane (68) as far as the second plane (69), characterized in that the channel portion (29) is formed separately from the guide bar (17), wherein the channel portion (29) is arranged in a fixed position in relation to the housing.

2. Implement according to Claim 1, characterized in that the longitudinal centre axis (61) of the guide bar (17) intersects the channel portion (29).

3. Implement according to Claim 1 or 2, characterized in that the channel portion (29) extends through the guide slot (50).

4. Implement according to one of Claims 1 to 3, characterized in that the channel portion (29) is formed at least in part in an extension (107, 117), which projects into a mount (120), wherein the oil-supply channel (60) runs through the mount (120), wherein, when the sprocket cover (20) is being removed from the housing, the extension (107, 117) is pulled out of the mount (120), and wherein the extension (107, 117) and the mount (120) are sealed in relation to one another by way of a seal (64, 114).

5. Implement according to Claim 4, characterized in that the seal (64, 114) is arranged on the circumference of the extension (107, 117).

6. Implement according to Claim 4 or 5, characterized in that the seal (64, 114) is arranged in a fixed position relative to the housing when the guide bar (17) is being displaced in relation to the housing.

7. Implement according to one of Claims 4 to 6, characterized in that the seal (64, 114) is arranged between the second plane (69) and an outer side (65) of the sprocket cover (20), this outer side being directed away from the housing.

8. Implement according to one of Claims 4 to 7, characterized in that the mount is a sleeve (30, 110).

9. Implement according to one of Claims 4 to 8, characterized in that the extension (107, 117) is formed by a guide element, and in that the channel portion (29) is in the form of a through-opening in the guide element.

10. Implement according to one of Claims 1 to 9, characterized in that an oil-supply slot (39) is formed in the sprocket cover (20), and is arranged opposite to the oil-supply opening (49) of the guide bar (17).

11. Implement according to Claim 10, characterized in that the channel portion (29) is connected to the oil-supply slot (39) via a connecting channel (38), which is open towards the bar-abutment surface of the sprocket cover (20).

12. Implement according to Claim 10 or 11, characterized in that the implement has a tensioning device (52), in that the guide bar (17) has a transverse plane (63), which contains the longitudinal centre axis (61) of the guide bar (17) and is perpendicular to the plane of the guide bar (17), and in that the oil-supply slot (39) and the tensioning device (52) are arranged on opposite sides of the transverse plane (63).

13. Implement according to one of Claims 1 to 12, characterized in that a second guide element is provided, which is in the form of a guide bolt (28) and has an external thread (62) on which to screw a fastening nut (21) for the purpose of fixing the sprocket cover (20).

14. Implement according to one of Claims 1 to 13, characterized in that the implement is a pole pruner (1) and the housing is a gearmechanism housing (19).