EP3456481B1 - Manually operated work device - Google Patents

Description

The invention relates to a hand-held implement of the type specified in the preamble of claim 1.

Hand-held tools with an internal combustion engine usually have one or more removable covers to enable maintenance and cleaning of the components of the tool. Such removable covers are known for example for the air filter box. By removing the air filter box cover, the air filter is accessible and can be cleaned and replaced if necessary. It may also be necessary to clean the cylinder, especially the cooling fins of the cylinder. The cylinder is therefore often arranged under a removable cover. For easy access to the spark plug, the spark plug can also be arranged under a cover of the implement. The spark plug can be arranged, for example, under the same cover as the cylinder or as the air filter. It is known to perform such closures with a rotatable actuating element. A hand-held implement is out DE-A-19530712 known.

The invention has for its object to provide a hand-held implement of the generic type, which has a simple and advantageous structure and allows easy handling.

This object is achieved by a hand-held implement with the features of claim 1.

It is envisaged that the closure has an elastic damping element for vibration-damping fixing of the cover. The damping element has a system for supporting the cover and a second system for supporting the tensioning element. The cover and the tensioning element do not have to be supported directly on the damping element, but can also be supported indirectly via further elements on the damping element. It is provided that the damping element is held on a portion of the cylinder in the axial direction of the axis of rotation of the closure. When the tensioning element is rotated from the unlocked position of the closure into the locked position of the closure, the tensioning element is moved by the tensioning contour in the axial direction of the axis of rotation. This axial movement of the tensioning element causes the tensioning element in the locked position of the closure to clamp the section of the cylinder in the axial direction of the axis of rotation between the first contact and the second contact of the damping element. In the unlocked position of the closure, the tensioning element is held on the damping element on the cylinder.

The damping element reduces the transmission of vibrations from the cylinder to the cover. Because the damping element is held on the section of the cylinder and the tensioning element is held in the unlocked position of the closure on the damping element, only the cover can be removed. The other components of the closure, namely in particular the tensioning element and the damping element, remain on the cylinder. Losing of these components is thus reliably prevented. At the same time there is a simple design of the cover. To fix the cover, the operator only has to put the cover on and turn the clamping element around its axis. It is not necessary to mount the tensioning element or the damping element on the cylinder or cover, since the tensioning element and the damping element are already held on the cylinder. This results in a simple structure and simple operation of the closure. The lid itself can be simple. Because the tensioning element is held on the cylinder via the damping element, the tensioning element is opposite the Cylinder is vibration-damped, and the transmission of vibrations via the clamping element to the cover is reduced.

The tensioning element advantageously has a tensioning section, a counter-holder and a shaft. The tensioning section advantageously has at least one locking element which is supported on the tensioning contour in the locked position of the closure. The at least one locking element and the counter-holder are connected to one another via the shaft, and the shaft projects at least partially through the damping element. The locking element and the counter-holder are in particular arranged on opposite axial ends of the clamping element. The locking element and the counter-holder advantageously act on the damping element and the cover from opposite sides and thus press the cover and the damping element against one another in the locked position of the closure.

The damping element advantageously has an opening in which the shaft is arranged. The area of the damping element surrounding the opening preferably at least partially covers the contour of the tensioning section in the unlocked position of the closure and thereby secures the tensioning element in the axial direction of the axis of rotation on the damping element. The clamping section accordingly engages behind the damping element adjacent to the opening. Additional elements for securing the tensioning element on the damping element can thus be omitted. Due to the elasticity of the damping element, an assembly of the tensioning element on the damping element is nevertheless advantageously possible. The damping element is in particular formed in one piece, and the mounting of the tensioning element on the damping element takes place with elastic deformation of the damping element.

The damping element advantageously has a slot which, in one position of the closure, lies at least partially in overlap with the at least one locking element. The slot is advantageously dimensioned such that the clamping section for mounting the clamping element on the damping element under elastic Deformation of the damping element can be pushed through the slot when the damping element is not held on the cylinder.

The damping element is advantageously arranged in a receptacle of the cylinder. In order to avoid that the tensioning element can be removed from the damping element while the damping element is deformed when the damping element is held on the cylinder, it is provided that the receptacle limits the elastic deformation of the damping element transversely to the axis of rotation and in particular transversely to the longitudinal direction of the slot, that the clamping element is held in a form-fitting manner on the damping element when the damping element is arranged in the receptacle of the cylinder. In the case of a damping element mounted on the cylinder, the tensioning element cannot therefore be removed from the damping element. Securing the position of the damping element and the tensioning element in the direction of the axis of rotation relative to the cylinder is achieved in a simple manner via the receptacle.

The receptacle advantageously ensures that the damping element is secured against rotation about the axis of rotation. This ensures that the damping element cannot rotate with the clamping element when the clamping element is rotated. This ensures that a defined relative movement takes place between the tensioning element and the damping element. A relative movement between the damping element and the cylinder that is hot during operation and after the internal combustion engine is switched off is thereby avoided. The wear of the damping element can thereby be reduced.

Because the damping element is secured against rotation relative to the cylinder, the position of the tensioning element in the unlocked or locked position can be secured via a latching device between the tensioning element and the damping element.

The inclusion preferably also limits or prevents bulging of the damping element. The positive rotation lock is advantageous compared to a rotation lock of the damping element via axial pressure, since even with reduced axial pressure of the damping element, in particular also when the lock is in the unlocked position, there is a rotation lock for the damping element.

The damping element is advantageously inserted into the receptacle in an insertion direction. The slot preferably runs approximately parallel to the direction of insertion. As a result, sides of the receptacle running in the insertion direction can easily prevent bulging of the damping element and secure the damping element in its rotational position.

At least one disk, in particular a disk made of metal, is advantageously arranged between the counter-holder and the second contact of the damping element. The disc reduces wear between the counter holder and the damping element. The counterholder advantageously rotates with the at least one locking element about the axis of rotation of the tensioning element. Due to the arrangement on the cylinder, which is very hot during operation, the damping element is subjected to high thermal loads and is therefore susceptible to wear. This wear can be reduced via the at least one disk between the counter-holder and the second contact of the damping element. By selecting a suitable friction pairing of counter-holder and disc, the operating forces that are to be applied to actuate the closure can be increased or decreased in a targeted manner, so that ergonomic actuation of the closure can be made possible.

A stop is advantageously formed between the tensioning element and the damping element, which defines the position of the tensioning element relative to the first contact of the damping element with respect to the axial direction of the axis of rotation such that in the unlocked position of the closure with the cover attached, the distance measured in the axial direction of the axis of rotation between the locking element and the counter holder is greater than the smallest distance measured in the axial direction of the axis of rotation between the clamping contour and the counter-holder. The distance between the locking element and the counter-holder is advantageously at least 1 mm, preferably at least 2 mm larger than the distance between the clamping contour and the counter-holder. Because the distance between the locking element and the counter-holder is greater than the distance between the clamping contour and the counter-holder, the at least one locking element protrudes beyond the lowest point of the clamping contour when the cover is attached. The distances between the locking element and the counter-holder or between the clamping contour and the counter-holder are preferably measured when the damping element is not loaded. As a result, when the cover is placed on the implement, the locking element already projects axially into the area or to the height level of the clamping contour if the cover has not yet been pressed onto the damping element. To fix the cover, the operator only has to put the cover on and turn the clamping element into the locked position. It is not necessary to press the cover because the locking element is already axially above the clamping contour when the cover is placed on it and the clamping contour in the cover automatically presses the cover against the damping element when the clamping element is turned into the locked position. This ensures easy handling of the closure.

The stop between the tensioning element, in particular the tensioning section, and the damping element advantageously also ensures that the locking element is at a distance from the damping element in the unlocked state. The distance is advantageous both with the cover attached and with the cover removed. The clamping contour engages in this distance between the locking element and the damping element and moves the clamping element during further rotation up to the locked position of the clamping element in the axial direction of the axis of rotation.

The tensioning element advantageously has means for adjusting the tensioning element between the unlocked position and the locked position of the closure. The means for adjusting the tensioning element can preferably have an engagement contour Engagement of a tool include. A gag on which the operator can directly actuate the tensioning element can also be advantageous. The means for adjusting the tensioning element are preferably arranged on the tensioning section. It can be advantageous to design the locking element and the means for adjusting the tensioning element on a component. The clamping contour and the means for adjusting the clamping element are advantageously provided on the same, preferably on the side of the closure protruding from the outside of the housing when the cover is attached. The counter-holder is advantageously arranged on the other side of the closure arranged inside the housing. The means for adjusting the tensioning element and the counterholders are preferably arranged on opposite sides of the section of the cylinder and on opposite sides of the cover. The means for adjusting the tensioning element are advantageously arranged on one end of the tensioning element, and the counter-holder is arranged on the other end, in particular the end of the tensioning element protruding into the housing. The means for adjusting the tensioning element and the counter-holder are advantageously provided on opposite sides of the shaft.

The closure advantageously has means for securing the rotational position of the tensioning element in the unlocked position. This ensures that the tensioning element does not rotate relative to the damping element in the unlocked position of the closure. If the cover is placed in the unlocked position of the tensioning element, the tensioning element is in the intended position and can be inserted directly through a housing opening. The housing opening is advantageously in overlap with the clamping section and is in particular adjacent to the clamping contour. To secure the rotational position of the tensioning element, a latching device acting between the tensioning element and the damping element is advantageously provided. A latching position is advantageously assigned to the position of the tensioning element in the unlocked position. In a preferred embodiment, a further latching position is assigned to the position of the tensioning element in the locked position. A position securing in the locked position is thus achieved via the latching device between the tensioning element and the damping element. The angle between the two locking positions advantageously corresponds to that Angle by which the clamping element is to be rotated about the axis of rotation between the unlocked position and the locked position. The angle between the unlocked and locked position is in particular less than 270 °, particularly suitably less than 180 °. Another latching device is preferably formed on the clamping contour and acts between the locking element and the cover. The further latching device advantageously has a latching position which is assigned to the locked position of the closure.

A simple design results if the latching device, which secures the rotational position of the tensioning element in the unlocked position, is formed between the shaft of the tensioning element and the opening of the damping element, in particular the peripheral contour of the opening of the damping element. In an alternative advantageous embodiment it is provided that this latching device is formed between the counter-holder and the damping element.

The damping element advantageously lies at least partially on a cooling fin of the cylinder. A receptacle, in which the damping element is arranged, is preferably formed on a cooling fin of the cylinder. The damping element advantageously has a limit stop which limits the depth of insertion into the receptacle of the cylinder. In a particularly advantageous embodiment, the damping element rests with the limit stop on the cooling fin of the cylinder.

The damping element is advantageously oriented such that the second contact of the damping element is inclined to at least one cooling fin of the cylinder. This is particularly advantageous if the cylinder longitudinal axis is arranged inclined in the housing, so that the cooling fins also run inclined relative to the upper side of the housing. The damping element is preferably bevelled on one transverse side. The bevel is advantageously designed such that the damping element does not or only slightly protrudes into a cooling channel formed between the cooling fins. Prefers the damping element protrudes by less than 2 mm into the cooling air duct formed between the cooling fins.

The clamping contour is advantageously arranged on the cover. In a preferred embodiment, the clamping contour is formed in one piece with the cover. The contour of the lid is advantageously made together with the clamping contour, in particular by injection molding, preferably made of plastic.

The closure advantageously consists of the clamping contour, the clamping element and the damping element. In the unlocked position of the closure, the clamping contour can advantageously be removed together with the cover, while the other components of the closure, namely the clamping element and the damping element, remain on the cylinder and are held on it.

The implement advantageously has a cover for the closure, which is held on the cover and which at least partially covers at least one locking element. In particular, if an engagement contour for engaging a tool is provided on the clamping element and is formed separately from the locking element, the operator does not need the locking elements to operate the closure. Characterized in that the locking elements and thus also the clamping contour are at least partially, preferably largely or completely covered by the cover, the tendency to contamination of the locking elements and clamping contour is reduced.

The clamping contour is advantageously formed by at least one ramp running in the circumferential direction to the axis of rotation. This results in an approximately helical course of the clamping contour which is wedge-shaped in one section in the circumferential direction.

Fig. 1

eine perspektivische Darstellung eines Arbeitsgeräts,

Fig. 2

eine ausschnittsweise Darstellung des Arbeitsgeräts aus Fig. 1 von oben,

Fig. 3

eine ausschnittsweise Schnittdarstellung entlang der Linie III-III in Fig. 2,

Fig. 4

eine perspektivische Darstellung des Deckels im Bereich des Verschlusses,

Fig. 5

eine Draufsicht auf den Ausschnitt des Deckels aus Fig. 4,

Fig. 6

eine perspektivische Darstellung der Oberseite des Deckels,

Fig. 7

eine perspektivische Darstellung der Unterseite des Deckels,

Fig. 8

eine perspektivische Darstellung von Dämpfungselement, Spannelement und Scheibe des Verschlusses,

Fig. 9

eine perspektivische Darstellung von Spannelement und Scheibe,

Fig. 10 und Fig. 11

perspektivische Darstellungen des Dämpfungselements,

Fig. 12

eine perspektivische Darstellung der Scheibe,

Fig. 13

eine perspektivische Darstellung einer Abdeckung,

Fig. 14

einen Schnitt durch Dämpfungselement, Spannelement und Scheibe entlang der Linie XIV-XIV in Fig. 15,

Fig. 15

einen Schnitt durch Dämpfungselement und Spannelement entlang der Linie XV-XV in Fig. 14,

Fig. 16

eine perspektivische Darstellung eines Ausführungsbeispiels von Dämpfungselement, Spannelement und Scheibe eines erfindungsgemäßen Verschlusses,

Fig. 17

eine Seitenansicht von Dämpfungselement, Spannelement und Scheibe aus Fig. 16,

Fig. 18

einen Schnitt entlang der Linie XVIII-XVIII in Fig. 17,

Fig. 19

eine perspektivische Darstellung eines weiteren Ausführungsbeispiels von Dämpfungselement, Spannelement und Scheibe eines erfindungsgemäßen Verschlusses,

Fig. 20

eine Seitenansicht von Dämpfungselement, Spannelement und Scheibe aus Fig. 19,

Fig. 21

einen Schnitt entlang der Linie XXI-XXI in Fig. 20.

Exemplary embodiments of the invention are explained below with reference to the drawing. Show it:

Fig. 1

a perspective view of an implement,

Fig. 2

a partial representation of the implement Fig. 1 from above,

Fig. 3

a partial sectional view along the line III-III in Fig. 2 ,

Fig. 4

a perspective view of the lid in the area of the closure,

Fig. 5

a plan view of the cutout of the lid Fig. 4 ,

Fig. 6

a perspective view of the top of the lid,

Fig. 7

a perspective view of the underside of the lid,

Fig. 8

a perspective view of the damping element, clamping element and disc of the closure,

Fig. 9

a perspective view of the clamping element and disc,

10 and 11

perspective representations of the damping element,

Fig. 12

a perspective view of the disc,

Fig. 13

a perspective view of a cover,

Fig. 14

a section through damping element, clamping element and disc along the line XIV-XIV in Fig. 15 ,

Fig. 15

a section through damping element and clamping element along the line XV-XV in Fig. 14 ,

Fig. 16

2 shows a perspective illustration of an exemplary embodiment of damping element, tensioning element and washer of a closure according to the invention

Fig. 17

a side view of the damping element, clamping element and disc Fig. 16 ,

Fig. 18

a section along the line XVIII-XVIII in Fig. 17 ,

Fig. 19

2 shows a perspective illustration of a further exemplary embodiment of the damping element, tensioning element and disk of a closure according to the invention,

Fig. 20

a side view of the damping element, clamping element and disc Fig. 19 ,

Fig. 21

a section along the line XXI-XXI in Fig. 20 .

Fig. 1 shows in perspective a hand-held implement 1. The implement 1 is a portable, hand-held chainsaw in the embodiment. However, the hand-held implement can be another implement, for example a brush cutter, cut-off machine, blower or the like. The implement 1 has a housing 2 in which an internal combustion engine 10 is arranged. The internal combustion engine 10 is in Fig. 1 only partially recognizable between the housing parts of the housing 2. To run the Tools 1, a rear handle 3 and a handle tube 4 are provided. The implement 1 has a guide rail 8 on which a schematically illustrated saw chain 9 is driven all round. The saw chain 9 is driven by the internal combustion engine 10. A hand guard 5, which is fixed to the housing 2, is arranged on the side of the handle tube 4 facing the saw chain 9. In a preferred embodiment, the hand guard 5 is used to actuate a braking device for the saw chain 9. A gas lever 6 and a gas lever lock 7 are pivotably mounted on the rear handle 3. The throttle lever 6 is used to control the internal combustion engine 10.

The housing 2 comprises a cover 13, which is fixed by a detachable closure 15. The cover 13 forms part of the outer shell of the implement 1. The cover at least partially covers the internal combustion engine 10 of the implement 1. In the exemplary embodiment, the cover 13 forms part of the housing 2. The housing 2 is composed of several components which can also have other functions. The housing 2 is in particular not a closed housing. The housing 2 also includes a detachably fixed air filter cover 14. An opening 58 is provided on the cover 13 and is arranged in a recess 57.

How Fig. 2 shows, protrudes through the opening 58, an actuating part of a decompression valve 70 of the internal combustion engine 10. The working device 1 has an in Fig. 2 schematically shown longitudinal center plane 67, which is parallel to the plane of the guide rail 8 ( Fig. 1 ) runs. The rear handle 3 is advantageously approximately parallel to the longitudinal central plane 67, preferably at least partially in the longitudinal central plane 67. The closure 15 and the decompression valve 70 are arranged approximately symmetrically to the longitudinal central plane 67 and on both sides of the longitudinal central plane 67. The closure 15 has an engagement contour 42 for engagement of a tool. In the exemplary embodiment, the engagement contour 42 is designed as a slot for the engagement of a screwdriver. How Fig. 2 also shows, extends outside of the engagement contour 42 a cover 43 fixed to the cover 13, which will be described in more detail below.

Fig. 3 shows the design of the closure 15 in detail. How Fig. 3 shows, the closure 15 comprises a damping element 17, a clamping element 21 and an integrally formed on the cover 13 clamping contour 16. The damping element 17 is held on a cylinder 11 of the internal combustion engine 10. The cover 13 at least partially covers the cylinder 11 of the internal combustion engine 10. The cylinder 11 has a plurality of cooling fins 12, between which cooling air channels 52 run. A fan wheel, not shown in the figures, drives cooling air through the cooling air channels 52. A receptacle 18 for the damping element 17 is formed on one of the cooling fins 12, in the exemplary embodiment on the upper cooling fin 12 facing the cover 13. The damping element 17 has a first section 33 and a second section 34. Between the sections 33 and 34 there run webs 35 which are set back with respect to the outer contour of the sections 33 and 34 and thus form recesses 40 into which a section 41 of the cylinder 11 engages. The damping element 17 is in one Fig. 2 The insertion direction 49 shown can be inserted into the receptacle 18 and can be removed from the receptacle 41 in the opposite direction. Further means for fixing the damping element 17 in the receptacle 18 are advantageously not provided. An opening 76 is formed on section 41 of cylinder 11, through which damping element 17 projects.

The clamping element 21 has a shaft 26, a clamping section 27 and a counter-holder 28. The clamping section 27 and the counter-holder 28 are arranged at opposite ends of the shaft 26 and are connected to one another via the shaft 26. Clamping section 27 and counter-holder 28 are advantageously at least partially formed with the shaft 26 from a single part. The clamping section 27 has at least one locking element 29. In the exemplary embodiment, two opposing locking elements 29 are provided. Another number of locking elements 29 can also be advantageous. The at least one locking element 29 is expediently designed as a separate part from the shaft 26 and is pushed or pressed into the clamping section 27.

The damping element 17 has a first system 19, which is supported on the cover 13. In the exemplary embodiment, the cover 13 lies directly against the first contact 19 of the damping element 17. The damping element 17 also has a second system 20, on which the counter-holder 28 is supported directly or indirectly. In the exemplary embodiment, a disk 32 is arranged between the counter-holder 28 and the second system 20. The disc 32 is made of metal. The width m of the disk 32 is greater than a width k of the opening 76 in the section 41 of the cylinder 11. The width m and the width k are measured in the same direction perpendicular to the axis of rotation 56 and in particular between the two cutouts 40. The width m of the disk 32 is advantageously at least 1.2 times, in particular at least 1.4 times the width k of the opening 76. The fact that the width m of the disk 32 is greater than the width k of the opening 76 prevents that the damping element 17 is deformed and its first section 33 can be partially pulled into the opening 76. The wear of the damping element 17 is thereby reduced.

Between the systems 19 and 20 there is the recess 40 into which the section 41 of the cylinder 11 projects. The system 19 lies against the inside of the cover 13. The clamping contour 16 is formed on the outside of the cover 13. How Fig. 3 shows, the clamping contour 16 is ramp or wedge-shaped in the circumferential direction. The clamping contour 16 is advantageously designed helically around an axis of rotation 56 of the clamping element 21. The clamping contour 16 advantageously extends only over a partial angle about the axis of rotation 56. In particular, the clamping contour 16 runs in a ramp around the axis of rotation 56. The partial angle is preferably smaller than the angle of rotation by which the clamping element 21 is rotated between the unlocked position and the locked position is. In the remaining circumferential section between the partial angle and the angle of rotation there is a locking recess 46 ( Fig. 4 ) for the locking element 29, which prevents the locking element 29 from slipping down, that is, from turning back on the ramp of the clamping contour 16.

Fig. 3 shows the closure 15 in the unlocked position 23. In this position, the clamping section 27 lies completely in register with a push-through opening 47 formed in the cover 13. The locking element 29 is not in contact with the clamping contour 16. The locking element 29 has a measured parallel to the axis of rotation 56 Distance a to the counter holder 28. The clamping contour 16 has a smallest distance b from the counter holder 28. The smallest distance b is advantageously measured at the area of the clamping contour 16 which, when the clamping element 21 is rotated from the unlocked position 23 into the locked position 22, first overlaps the locking element 29. The distance b is smaller than the distance a, so that the clamping contour 16 can engage under the locking element 29 when the clamping element 21 is rotated. For this purpose, the clamping element 21 is secured in its position in the direction of the axis of rotation 56 relative to the damping element 17, as will be described in more detail below. Fig. 3 shows the arrangement of the closure 15 after the cover 13 has merely been put on. The cover 13 has not been pressed down by the operator, so that the damping element 17 is not compressed by the cover 13.

How Fig. 3 also shows, the locking element 29 in the in Fig. 3 Unlocked position 23 shown a distance g to the damping element 17. Because the locking element 29 lies above the damping element 17, the clamping contour 16 can easily reach under the locking element 29, that is to say between the damping element 17 and the locking element 29. The position designations "above" or "above" and "below" or "below" refer to a vertical arrangement of the axis of rotation 56 and an arrangement of the clamping section 27 above the counter-holder 28. This position is shown in FIG Fig. 3 shown. In this position, the axis of rotation 56 lies in the effective direction of gravity, and the tensioning element 21 advantageously supports its gravity on the tensioning section 27 against the damping element 17.

If the clamping element 21 is rotated in the direction of the locked position 22, the locking element 29 comes into contact with the clamping contour 19. The clamping contour 19 moves the clamping element 21 in the direction of the axis of rotation 56 in a clamping direction 24. The clamping direction 24 is directed from the counter-holder 28 to the clamping section 27. As a result, the cover 13 is pressed over the clamping contour 16 to the cylinder 11 and the damping element 17 is compressed in the process. The section 41 of the cylinder 11 remains stationary while the clamping element 21 is in Fig. 3 up and the lid 13 in Fig. 3 move downwards, i.e. towards cylinder 11. How Fig. 3 also shows, the clamping section 27 is arranged in a recess 25 of the cover 13, which is covered by the cover 43 ( Fig. 2 ) is partially closed.

How Fig. 3 also shows, the damping element 17 has a bevel 37 on its side facing away from the cover 13 Fig. 3 shows, the cooling channels 52 run at an angle to the axis of rotation 56. The damping element 17 is therefore also at an angle to the cooling channels 52. The bevel 37 is arranged such that the damping element 17 does not protrude into the cooling air channel 52, or does so only insignificantly. The bevel 37 is advantageously designed such that the damping element 17 projects less than 2 mm into the cooling air duct 52 formed between the cooling fins 12. In the exemplary embodiment, the bevel 37 lies in one plane with the underside of the adjacent cooling fin 12. The bevel 37 is arranged on the first section 33 of the damping element 17 arranged in the receptacle 18.

Fig. 4 shows the cover 13 with the portion of the tensioning element 21 projecting to the outside of the housing 2 Fig. 4 shows, two opposing locking elements 29 are provided. In the in Fig. 4 Unlocked position 23 shown, the locking elements 29 as well as the clamping section 27 of the clamping element 21 are in overlap with the push-through opening 47 of the cover 13. In the unlocked position 23, the cover 13 can thereby be placed on the clamping element 21 or lifted off the clamping element 21. How Fig. 4 also shows, a clamping contour 16 is arranged in the circumferential direction adjacent to each locking element 29, which extends helically. A locking recess 46 adjoins each clamping contour 16, which defines the locked position of the closure 15.

Fig. 5 shows the locked position 22 schematically with a broken line. In the locked position 22, the locking elements 29 lie in the associated locking recesses 46 4 and 5 are also shown locking openings 48 of the lid 13, in which the cover 43 is to be fixed.

In the exemplary embodiment, the clamping element 21 is to be rotated about the axis of rotation 56 for locking in a direction of rotation 45. In the exemplary embodiment, the direction of rotation 45 runs clockwise from above when the cover 13 is viewed. As the 4 and 5 also show, 13 elevations 73 are formed on the cover, which prevent the clamping element 21 from rotating in the opposite direction, that is to say counterclockwise in the exemplary embodiment. In the exemplary embodiment, the elevations 73 also serve to position the cover 43. Between the unlocked position 23 and the locked position 22, the tensioning element 21 can be rotated by 90 ° in the exemplary embodiment. Another angle of rotation between the unlocked position 23 and the locked position 22 can, however, also be advantageous. However, the angle of rotation is less than 360 °, so that the tensioning element 21 can be rotated by less than one turn between the unlocked position 23 and the locked position 22. In particular, the angle of rotation is less than 180 °, so that the clamping contour 16 extends only on one side of the push-through opening 47.

The 6 and 7 show the design of the lid 13 in detail. How Fig. 6 shows, the push-through opening 47 is gag-shaped with an approximately circular central region and two narrower regions extending radially outward therefrom. The contour of the push-through opening 47 advantageously corresponds approximately to the contour of the clamping section 27 including the locking elements 29 6 and 7 the locking openings 48 for the cover 43 are also shown. In the 6 and 7 opening 58 for decompression valve 70 can also be seen. With the cover 13 removed, only the push-through opening 47 and the clamping contour 16 of the closure 15 is formed. The other components of the closure 15 are held on the cylinder 11.

In Fig. 7 support bolts 74 and 75 are arranged. In the exemplary embodiment, three support bolts 74 and one support bolt 75 are provided, which approximately span a square. The support bolts 74 and 75 are supported on damping elements, not shown, on components of the implement 1 connected to the cylinder 11 or a crankcase, not shown, and thus support the cover 13 in the axial direction of the axis of rotation 56. In the exemplary embodiment, the support bolts 74 plunge into rubber-mounted ones Sleeves and thus secure the cover 13 in the vertical direction to the axis of rotation 56. The support pin 75 is immersed in a damping element which rests only on a rib of the cylinder 11, so that the cover 13 is supported only in the axial direction of the axis of rotation 56.

Fig. 8 shows the components held on the cylinder 11, namely the damping element 17, the tensioning element 21 and the disk 32. Fig. 8 shows the arrangement in a preassembled state in which the arrangement in the receptacle 18 of the cylinder 11 ( Fig. 3 ) in the in Fig. 2 Insert direction 49 shown can be inserted.

As the 8 and 9 show, the disc 32 has a rectangular shape. The disc 32 is arranged in a recess 64 of the damping element 17. The bottom of the recess 64 forms the second plant 20. The recess 64 is like Fig. 10 shows, surrounded by a peripheral wall 65. The peripheral wall 65 encloses the disk 32 closely on its periphery or at a very small distance, so that the disk 32 is secured against rotation from the peripheral wall 65 of the recess 64 with respect to the damping element 17.

How Fig. 9 shows, the shaft 26 has a non-circular, preferably polygonal, in the exemplary embodiment a square cross-section. The disc 32 has one Opening 72 ( 9 and 12 ), which has a round cross section in the exemplary embodiment. The opening 72 is dimensioned such that the tensioning element 21 can rotate freely in the opening 20. As the 8 and 9 also show, the counter-holder 28 is designed in the embodiment as a disk with a circular cross-section. The shaft 26 has a first end 30 on which the clamping section 27 is arranged. The shaft 26 also has a second end 31 on which the counter-holder 28 is arranged. The counter-holder 28 and the clamping section 27 are accordingly arranged at opposite ends of the shaft 26. The shaft 26 protrudes as Fig. 8 combined with Fig. 9 shows by the damping element 17th

As the 8 and 10 show, recesses 40 are formed between sections 33 and 34 of damping element 17, into which section 41 of cylinder 11 engages ( Fig. 3 ). A limit stop 38 is also formed on the damping element 17, on which the first section 33 is made thicker. The limit stop 38 limits the insertion depth of the damping element 17 into the receptacle 18 ( Fig. 3 ). As the 8 and 10 show, the bevel 37 is formed on a transverse side 51 of the damping element 17. The sections 33 and 34 are connected via two webs 35. The webs 35 extend between the two cutouts 40. In the exemplary embodiment, the first section 33 has a rectangular cross section, while the second section 34 has a round cross section.

How in particular Fig. 11 shows, the damping element 17 has a slot 36. The webs 35 are separated from one another by the slot 36. In the exemplary embodiment, the slot 36 extends over the entire diameter of the second section 34 and extends through the second section 34 in a direction perpendicular to the axis of rotation 56 ( Fig. 9 ). How Fig. 11 also shows, the damping element 17 has an opening 39 for the shaft 26. A stop 50 is formed on the second section 34 adjacent to the opening 39, at the region of the damping element 17 surrounding the opening. In the exemplary embodiment, the stop 50 is designed as a depression in the damping element 17. The stop 50 covers the contour of the clamping section 27 at least in unlocked position 23 of the closure 15 at least partially. In the exemplary embodiment, the stop 50 covers the contour of the clamping section 27 in any position of the clamping element 21. The clamping section 27 of the clamping element 21 lies on the stop 50 ( Fig. 9 ) at. As a result, the clamping element 21 is secured in position in relation to the damping element 17 in the direction of the axis of rotation 56. How Fig. 11 also shows, the opening 39 has a square cross section which corresponds to the cross section of the shaft 26 with little play. The opening 39 and the shaft 26 form a detent 53 due to their coordinated, non-circular cross-section ( Fig. 14 ), which defines four locking positions of the shaft 26 relative to the damping element 17 in the exemplary embodiment. Due to the symmetrical design of the tensioning element 21, two of the locking positions are assigned to the unlocked position 23 and the other two locking positions are assigned to the locked position 22 of the closure 15. Because a locked position is also assigned to the locked position 22, the shaft 26 lies in the locked position 22 with little play in the opening 39. As a result, the damping element 17 is in the locked state 22, that is to say also when the implement 1 is in operation, transverse to the axis of rotation 56 relaxed at the opening 39, and the load on the damping element 17 and thus the wear are reduced. In the exemplary embodiment, an angle of 90 ° is provided between the locked position 22 and unlocked position 23 of the at least one locking element 29. This angle thus corresponds to the angle between the locking positions of the locking device 53.

How Fig. 13 shows, the cover 43 has an opening 44 through which the engagement contour 42 is accessible from the outside. The locking elements 29 are largely, in particular completely, covered by the cover 43, in particular Fig. 2 shows. Snap-on elements 71 are integrally formed on the cover 43, which can be inserted into the snap-in openings 48 of the lid 13 and locked there on the lid 13 ( 4 and 5 ). The view 43 on the locking element 29 and the push-through opening 47 of the cover 13 is made more difficult or prevented by the cover 43. A simple placement of the cover 13 is still possible, since the locking device 53 between the clamping element 21 and damping element 17 prevents inadvertent rotation of the tensioning element 21 during or after removal of the cover 13. As a result, the position of the locking element 29 after the cover 13 has been removed corresponds to the position before the cover 13 is put back on again. Since the cover 13 can only be put on or taken off in one orientation, the locking elements 29 and the push-through opening 47 are automatically aligned with one another . A visual inspection of the orientation of the locking element 29 or even a turning of the tensioning element 21 is unnecessary in order to place the cover 13 correctly on the damping element 17.

The 14 and 15 show clamping element 21, damping element 17 and disc 32 in the assembled state. As the 14 and 15 show, the clamping element 21 is constructed from a support member 59 through which a bolt 60 protrudes. The support component 59 forms the counter-holder 28, the shaft 26 and the central part of the clamping section 21. The counter-holder 28, shaft 26 and part of the clamping section 21 are accordingly constructed in one piece. The bolt 60 forms the two locking elements 29. The bolt 60 is inserted through an opening 61 of the carrier component 59 and extends transversely, in the exemplary embodiment perpendicular to the axis of rotation 56. It can be provided that the carrier component 59 is first mounted on the damping element 17 without the bolt 60 and the bolt 60 is inserted into the support component 59 only after the mounting of the support component 59 on the damping element 17. Alternatively, the tensioning element 21 can be pushed through the damping element 17 in an advantageous embodiment including the bolt 60. The damping element 17 is designed such that the slot 36 and the opening 39 can be widened with elastic deformation of the damping element 17, so that at least the tensioning section 27 can advantageously also be inserted with the locking elements 29 installed. Then the assembly of damping element 17, clamping element 21 and washer 32 in the insertion direction 49 ( Fig. 2 ) in the receptacle 18 of the cylinder 11 ( Fig. 3 ) assembled.

As the 10 and 11 show, the slot 36 runs parallel to the transverse side 51. Accordingly, the slot 36 also runs parallel to the longitudinal walls of the receptacle 18. If the damping element 17 is mounted on the cylinder 11, the slot 36 can no longer be widened significantly. How Fig. 3 shows, the damping element 17 lies with its transverse sides 51 in the exemplary embodiment on the side walls of the receptacle 18. The receptacle 18 prevents both expansion of the damping element 17 and rotation of the damping element 17 about the axis of rotation 56. The slot 36 is dimensioned such that the locking element 29 or the tensioning element 21 can only be pushed through the slot 36 if that Damping element 17 is not held on the cylinder 11. After the damping element 17 has been mounted on the cylinder 11, the tensioning element 21 can no longer be fitted or removed on the damping element 17.

As the 14 and 15 show, the counter-holder 28 and the stop 50 define the axial position of the clamping element 21 on the damping element 17. In Fig. 15 the locking device 53 is also shown, which is formed between the shaft 26 of the clamping element 21 and the contour of the opening 39 in the damping element 17. How Fig. 14 shows, the clamping section 27 has a diameter c. The diameter c is larger than the largest diameter d of the shaft 26. The diameter c is also larger than the largest diameter h of the opening 39, which in FIG Fig. 11 is drawn. Adjacent to the counter-holder 28, the shaft 26 has a shoulder 62 with an enlarged diameter, such as Fig. 14 shows. The shoulder 62 also secures the axial position of the locking element 21 on the damping element 17. In the exemplary embodiment, the locking element 21 is mounted on the damping element 17 without play, preferably with a slight preload of the damping element 17. The counter-holder 28 has a diameter e which is significantly larger than the largest diameter d of the shaft 26 and larger than the largest diameter h of the opening 39 ( Fig. 11 ) is.

How Fig. 14 also shows, the disc 32 extends almost the entire width and length of the recess 64. Wie Fig. 14 shows is little play between the Washer 32 and the peripheral wall 65 are provided. A circumferential groove 63 runs on the edge of the disk 32 adjacent to the system 20 in the damping element 17. The circumferential groove 63 reduces the tension in the compressed damping element 17 and reduces the wear between the disk 32 and the damping element 17 at the edge of the disk 32 Fig. 14 shows, the slot 36 extends to narrow wall portions 66 which extend to the peripheral wall 65 at the second portion 34. The wall sections 66 extend as far as the first section 33 and connect the sections 33 and 34 to one another in the region of the slot 36, as well 8 and 11 demonstrate. Sections 33 and 34 are also connected via webs 35 ( Fig. 15 ) connected.

In Fig. 15 the bevel 37 on the transverse side 51 is also clearly visible.

The 16 to 21 show two further exemplary embodiments of a closure 15, only the damping element 17, the tensioning element 21 and the disk 32 being shown. The same reference numerals designate corresponding elements in all exemplary embodiments. In contrast to the first exemplary embodiment, the latching device in the following exemplary embodiments is formed between the counter-holder of the tensioning element 21 and the damping element 17.

In the in the 16 to 18 In the exemplary embodiment shown, the tensioning element 21 has a counter-holder 68 which has a square contour with strongly rounded corners. The width f of the square contour of the counter-holder 68 corresponds to the distance between opposite circumferential wall sections 69 of the damping element 17. The rotational position of the counter-holder 68 is defined via the circumferential wall sections 69. With elastic deformation of the circumferential wall sections 69, the counter-holder 68 can be rotated and the diagonal of the square contour between the mutually opposite circumferential wall sections 69 can be rotated, in the exemplary embodiment in steps of 90 °. The counter-holder 68 and the peripheral wall sections 69 form a latching device 54. The first section 33 of the damping element 17 is shown in the exemplary embodiment Fig. 16 narrower than in the embodiment of the previous figures. Because the counter-holder 68 is not arranged in a recess with a closed peripheral wall, no peripheral wall sections protrude into a cooling air duct 52 of the cylinder 11 ( Fig. 3 ) so that a bevel is not necessary. Instead of a bevel, the wall sections connecting the peripheral wall sections 69 are missing.

In the 19 to 21 Another exemplary embodiment of damping element 17, tensioning element 21 and disk 32 is shown. The clamping element 21 shown here has a counter-holder 78, the shape of which corresponds to the shape of the counter-holder 68. The counter-holder 78 is, however, arranged in a recess 64 which is delimited by a circumferential peripheral wall 65. The counter-holder 78 forms a latching device 55 with the peripheral wall 65. The counter-holder 78 defines rotational positions of the locking element 21, which are at an angular distance of 90 ° to one another. One of the rotational positions corresponds to the unlocked position 23 of the closure 15, and the other rotational position corresponds to the locked position 22.

Claims (15)

1. Hand-guided working implement with an internal combustion engine for driving a tool of the working implement, wherein the internal combustion engine has a cylinder (11), wherein the working implement (1) comprises a removable cover (13) fixed by a closure (15), wherein the closure (15) comprises a clamping element (21) rotatable about an axis of rotation (56), wherein the clamping element (21) is supported on a clamping contour (16) in the locked position (22) of the closure (15) and has to be rotated by less than a whole revolution for moving from the unlocked position (23) into the locked position (22), characterised in that the closure (15) has an elastic damping element (17) for the vibration-damping location of the cover (13), in that the damping element (17) has a first contact surface (19), on which the cover (13) is supported in the axial direction of the axis of rotation (56), in that the damping element (17) has a second contact surface (20), on which the clamping element (21) is supported in the axial direction of the axis of rotation (56), in that the damping element (17) is held at a section (41) of the cylinder (11) in the axial direction of the axis of rotation (56), in that the clamping element (21) is moved by the clamping contour (16) in the axial direction of the axis of rotation (56) at a rotation from the unlocked position (23) of the closure (15) into the locked position (22) of the closure (15), in that the clamping element (21) clamps the section (41) of the cylinder (11) in the axial direction of the axis of rotation (56) between the first contact surface (19) and the second contact surface (20) in the locked position (22) of the closure (15), and in that the clamping element (21) is held at the damping element (17) at the cylinder (11) in the unlocked position (23) of the closure (15).
2. Working implement according to claim 1,
   characterised in that the clamping element (21) has a clamping section (27), a back rest (28) and a shank (26), wherein the clamping section (27) has at least one locking element (29), wherein the at least one locking element (29) is supported on the clamping contour (16) in the locked position (22) of the closure (15), wherein the at least one locking element (29) and the back rest (28) are joined to each other by the shank (26), and wherein the shank (26) extends at least partially through the damping element (17).
3. Working implement according to claim 2,
   characterised in that the damping element (17) has an opening (39) in which the shank (26) is located, wherein the region of the damping element (17) which surrounds the opening at least partially covers the contour of the clamping section (27) in the unlocked position (23) of the closure (15), thereby securing the clamping element (21) at the damping element (17) in the axial direction of the axis of rotation (56).
4. Working implement according to claim 3,
   characterised in that the damping element (17) has a slot (36), which at least partially overlaps the at least one locking element (29) in a position (23) of the closure (15), wherein the slot (36) is dimensioned such that the clamping section (27) can be pushed through the slot (36) with elastic deformation of the damping element (17) for mounting the clamping element (21) at the damping element (17) if the damping element (17) is not held at the cylinder (11).
5. Working implement according to any of claims 2 to 4,
   characterised in that the damping element (17) is located in a receptacle (18) of the cylinder (11), and in that the receptacle (18) secures the damping element (17) against rotation about the axis of rotation (56).
6. Working implement according to any of claims 2 to 5,
   characterised in that at least one disc (32) is located between the back rest (28, 68, 78) and the second contact surface (20) of the damping element (17).
7. Working implement according to any of claims 2 to 6,
   characterised in that between the clamping element (21) and the damping element (17) a stop (50) is formed, which determines the position of the clamping element (21) with respect to the first contact surface (19) of the damping element (17) with reference to the axial direction of the axis of rotation (56) in such a way that, in the unlocked position (23) of the closure (15) and with the cover (13) fitted, the distance (a) between the locking element (19) and the back rest (28) as measured in the axial direction of the axis of rotation (56) is greater than the minimum distance (b) between the clamping contour (16) and the back rest (28) as measured in the axial direction of the axis of rotation (56).
8. Working implement according to any of claims 2 to 7,
   characterised in that the clamping element (21) has means for moving the clamping element (21) between the unlocked position (23) and the locked position (22) of the closure (15), the means for moving the clamping element being located at the clamping section (27).
9. Working implement according to any of claims 1 to 8,
   characterised in that a latching device (53, 54, 55) acting between the clamping element (21) and the damping element (17) is provided to secure the rotary position of the clamping element (21), wherein a latching position is assigned to the position of the clamping element (21) in the unlocked position (23).
10. Working implement according to claim 9,
    characterised in that the latching device (53) is formed between the shank (26) of the clamping element (21) and the opening (39) of the damping element (17).
11. Working implement according to claim 9,
    characterised in that the latching device (54, 55) is formed between the back rest (28) and the damping element (17).
12. Working implement according to any of claims 1 to 11,
    characterised in that the damping element (17) at least partially lies against a cooling fin (12) of the cylinder (11).
13. Working implement according to any of claims 1 to 12,
    characterised in that the second contact surface (20) is inclined with respect to at least one cooling fin (12) of the cylinder (11), and in that the damping element (17) is chamfered on a transverse side (51).
14. Working implement according to any of claims 1 to 13,
    characterised in that the clamping contour (16) is located on the cover (13).
15. Working implement according to any of claims 1 to 14,
    characterised in that the working implement has a cover (43) for the closure (15), which is held on the cover (13) and at least partially covers at least one locking element (29).

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