WO2010025803A2

WO2010025803A2 - Lawn trimmer

Info

Publication number: WO2010025803A2
Application number: PCT/EP2009/005726
Authority: WO
Inventors: Bernhard Besserer; Ottmar Locher
Original assignee: Gardena Manufacturing Gmbh
Priority date: 2008-08-26
Filing date: 2009-08-07
Publication date: 2010-03-11
Also published as: EP2334162A2; WO2010025803A3; DE102008045912A1

Abstract

The invention relates to a lawn trimmer having a cutting head (2), a guide handle (3), and a hinge arrangement (4), comprising a first (40) and a second axis (44), wherein the cutting head (2) can be pivoted relative to the guide handle (3) about the first axis (40) between at least one first and one second tilt position and the cutting head (2) can be pivoted relative to the guide handle (3) about the second axis (44) between an edge cutting position and a trimming position, and the hinge arrangement (4) comprises pivot-locking means by which pivoting of the cutting head (2) about the second axis (44) between the trimming position and the edge cutting position is blocked in the first tilt position, and/or by which pivoting of the cutting head (2) about the first axis (40) is blocked in the edge cutting position.

Description

Description grass trimmer

The invention relates to a trimmer with a cutting head, a guide stem and a hinge assembly comprising a first and a second axis, wherein the cutting head is pivotable relative to the guide stem about the first axis between at least a first and a second tilt position and the cutting head relative to the Guide stem about the second axis between an edge cutting position and a trim position is pivotable.

As a grass trimmer hand-held by means of a guide handle garden cutting device is referred to, which has on a cutting head one or more rotating cutting tools, in particular radially outwardly pointing knife blades, or at least one mowing thread.

A thread cutter with a double joint arrangement is known, for example, from WO 2005/009110. The double joint arrangement has a first axis and a second axis. The first axis intersects the axis of the guide stem vertically and allows a tilting movement to adjust a tilt position of the cutting unit or Cutting head opposite the guide shaft. The cutting head may be further pivoted about a second axis between the trim position and a vertical cutting position or edge cutting position. In the edging position, also referred to as edging position, laterally protruding plant parts can be trimmed. The cutting unit can be fixed in different pan and / or tilt positions, with a fixation in unneeded and / or in view of possible risk of injury not suitable inclination and / or pivot positions is prevented. However, several handles may be necessary to arrange the cutting unit relative to the guide stem so that a fixation is possible.

It is therefore an object of the present invention to provide a lawn trimmer, which is adjustable in a simple manner and for a user safely between different positions of use.

This object is achieved by a grass trimmer having a cutting head, a guide stem and a joint arrangement, comprising a first and a second axis, wherein the cutting head is pivotable relative to the guide stem about the first axis between at least a first and a second tilt position, the cutting head relative is pivoted to the guide shaft about the second axis between an edge cutting position and a trim position and the hinge assembly comprises pivot locking means, which is locked in the first tilt position pivoting of the cutting head about the second axis between the trim position and the edge cutting position and / or by which in the Edge cutting position a pivoting of the cutting head is locked around the first axis

The cutting head can be adjusted by the hinge assembly relative to the guide shaft for various tasks. The first axis for a pivoting movement for adjusting an inclination angle is preferably substantially parallel to a plane perpendicular to a longitudinal axis of the guide shaft. In one embodiment, the first axis lies in this plane. As the angle of inclination is referred to in the context of the invention, an angle at which the guide post protrudes in use of the cutting head. The angle of inclination may be defined, for example, between the guide shaft and a plane in which a cutting line or a cutting blade circulates. The tilt position and / or the cutting position can each be fixed by suitable means.

By the pivot locking means prevents the cutting head can occupy inadmissible positions relative to the guide stem, which would have to be corrected before re-fixing the cutting head on the guide stem - as usual in the art - and / or which could pose a potential risk.

The pivot locking means are preferably designed so that they can not be bypassed by a user non-destructive. In other words, in one embodiment, a release of the pivot locking means and thus a switch to the edge cutting position is possible only by pivoting from the first tilt position into a deviating second inclination position.

Alternatively or additionally, pivoting about the first axis is blocked by the pivot locking means in the edge cutting position. In a trimming position of the trimmer, different inclination positions of the cutting head relative to the guide post may be advantageous. In an edge position, however, a change in the angle of inclination for safety reasons is not desirable. In order to prevent an unwanted swiveling occurring, therefore, Pivoting locking means are provided according to the invention, which preferably can not be bypassed without destruction.

In one embodiment of the invention it is provided that the first axis is arranged substantially horizontally in a position of use. A corresponding axis has proved to be particularly advantageous for setting a tilt position.

In one development of the invention, the first and the second axis are arranged at a distance from the joint arrangement in the direction of the guide stem, wherein the first axis is arranged on a side facing away from the guide stem and the second axis on a side facing the guide stem. The arrangement is advantageous for ergonomic and / or structural reasons.

In one embodiment of the invention it is provided that the first axis is formed by a fork which engages around the cutting head and is operatively connected to the guide shaft. The cutting head usually comprises in addition to the cutting device and a motor or the like, which is mounted with the cutting device in a common housing. The cutting head thus has a significant share of a total weight of the grass trimmer. By storage by means of a fork with respect to a center of gravity arrangement favorable design can be created. On the fork O-rings and the like. Be provided for a vibration damping.

The pivot locking means preferably comprise a first actuating element, which cooperates with a locking structure provided on the cutting head for determining a tilt position. The actuating element is therefore also locking element. The latching structure is provided in one embodiment on a housing of the cutting head. When storing the cutting head by means of a fork, the actuating ,

ment provided on the fork. In this case, in one embodiment, the actuating element may be arranged centrally in order to achieve a uniform load distribution.

In one embodiment of the invention, the first actuating element is force-loaded, in particular spring-loaded. The actuating element is held in a detent position by means of an acting constraining force, preferably a spring force, wherein for pivoting an adjustment of the actuating element takes place against the constraining force.

In a further embodiment of the invention, the actuating element is designed as a slide, lever, rocker or the like, in particular as a spring-loaded slide or the like. In the context of the invention, a slider is referred to as an element which is displaced to an actuation, i. performs a movement along a guideway, preferably a linear guideway. Such slides can be realized particularly cost-effective and robust. As a rocker or lever, however, elements are referred to, which are pivoted for actuation.

In one embodiment of the invention, the actuating element in the first inclination position locked to the latching structure such that the actuating element prevents pivoting from the trim position in the edge cutting position. The actuator for adjusting the tilt position is used directly as a blocking element of the pivot locking means and the number of moving parts on the trimmer lawn is thus kept as low as possible.

In a further embodiment of the invention, the actuating element locked in the second inclination position with the latching structure such that the actuating element releases a pivoting from the trim position in the edge cutting position. In the second position is Thus, the angle of inclination is fixed by the actuating element, whereas pivoting about the second axis is not blocked by the actuating element.

In yet another embodiment of the invention, it is provided that the actuating element is at least partially guided in a groove with a first, the cutting head portion associated, and a second, the guide stem associated portion, wherein the first and the second portion arranged in alignment in the trim position are such that the actuating element for pivoting about the first axis in the groove is displaceable, and the first and the second portion are not aligned in the edge cutting position, so that a displacement of the actuating element for pivoting about the first axis is locked. In other words, preferably, by pivoting the cutting head into the edge cutting position, shifting the actuator to pivot the cutting head about the first axis, i. for changing the tilt position, locked. As a result, the pivoting about the first axis when setting the edge cutting position is locked without additional manipulations.

In a further embodiment of the invention, the second axis encloses an angle in the range of approximately 30 ° to approximately 60 °, preferably approximately 45 °, with a longitudinal axis of the guide stem. Preferably, the second axis is coaxial with a central surface normal on two mutually sliding surfaces in a guide shaft intersecting inclined plane. An associated with the second axis joint is realized in one embodiment by a spar, which is arranged coaxially with the guide stem to this subsequently. The mutually facing sides of the guide stem are inclined with respect to the longitudinal axis of the guide stem. In one embodiment of the invention, a second actuating element for fixing the trim position or the edge cutting position is provided. The second actuating element can also be designed as a slide. Preferably, the second actuating element is designed as a rocker with an actuatable by applying a compressive force element. For example, the second actuating element is arranged on the guide stem and cooperates with the suspension of the cutting head, for example with the fork.

In a further embodiment, a wheel arrangement for a wheel support in the trim position and / or the edge cutting position is arranged on the guide stem, in particular arranged pivotably. The wheel assembly is preferably without tools by latching means or the like with the guide stem connected as needed. By a pivot axis, the wheel assembly can be placed either in a position of use or in a voltage applied to the guide handle stowage position. Preferably, the wheel assembly has a curved strut, wherein the curvature is configured so that the strut is disposed in a use position outside a pivot radius of the cutting head when adjusting about the first and / or the second axis. The cutting head can be pivoted so without additional adjustment of the wheel assembly between the trim position and the edge cutting position.

Further advantages of the invention will become apparent from the subclaims and from the following description of embodiments of the invention, which are shown schematically in the drawings. For identical or similar components, the same reference numbers are used in the drawings. Features described or illustrated as part of one embodiment may also be used in another embodiment to obtain a further embodiment of the invention. In the drawings show:

Fig. 1: a schematic side view of an inventive

Grass trimmer in a first position of use;

FIG. 2 shows a schematic side view of the grass trimmer according to FIG. 1 in a second position of use; FIG.

FIG. 3 is a schematic side view of the grass trimmer according to FIG. 1 in a third position of use; FIG.

4 shows a schematic side view of the grass trimmer according to FIG. 1 in a fourth position of use;

FIG. 5 shows the grass trimmer according to FIG. 1 during pivoting between the third and the fourth use position; FIG.

6 shows a partially cut detail view of a first pivot lock according to the invention

Fig. 7: a partially sectioned detail of the first

Swing lock in a second view.

FIGS. 1 to 4 schematically show a grass trimmer 1 according to the invention in different positions of use. The illustrated grass trimmer 1 comprises a cutting head 2 and a guide stem 3, which are connected to one another via a joint arrangement 4. On the guide shaft 3, a wheel assembly 5 is pivotally mounted in the illustrated embodiment. 1 shows the grass trimmer 1 in a first position, which is referred to as "free cutting." Fig. 2 shows the grass trimmer 1 in a second position, which is similar to the position shown in Fig. 1, but with the wheel assembly 5 assisting the user in cutting. Fig. 3 shows the trimmer 1 in a flat position, which is suitable for example for cutting under an obstacle, not shown, or the like. Fig. 4 shows the trimmer in a so-called edge cutting position, wherein the cutting head 1 is brought into a vertical position. Fig. 5 shows schematically a rotation of the cutting head from the trim position shown in FIGS. 1 to 3 in the illustrated in Fig. 4 edge cutting position. The cutting head 2 comprises a housing 20, in which a non-visible motor for rotating drive of a mowing thread, not shown, is mounted about an axis of rotation 24. On the housing 20, a protective cover 25 is preferably provided.

A plane in which the cutting thread or another cutting tool rotates is referred to as the cutting plane S. By the illustrated hinge assembly 4, an adjustment of an inclination angle α between the guide shaft 3 and the cutting plane S is possible. In this case, the guide stem 3 and the cutting plane S in the inclined position shown in Fig. 3 are substantially parallel, so that the included angle α is about 0 °. The hinge assembly 4 further allows pivoting of the cutting head 2 relative to the guide shaft 3 for a change between a trim position, in which cutting substantially parallel to the ground, and an edge cutting position shown in Fig. 4, in which the cutting plane S substantially is arranged vertically. The joint assembly 4 comprises for this purpose a first axis 40 which is provided on a fork 41, wherein the cutting head 2 is arranged pivotable about the first axis 40 relative to the fork 41 for adjusting the inclination angle α. The first axis 40 is arranged substantially horizontally in the illustrated positions of use. The hinge assembly 4 further comprises a spar 42, which is in one piece is formed with the fork 41, wherein the guide shaft 3 is pivotable relative to the spar 42 about a second axis 44 between the trim position and the edge cutting position.

In the illustrated embodiment, the cutting head 2 is locked by the housing 20 - as shown in FIGS. 1 to 3 - in three inclination positions with the fork 41. The housing 20 has for this purpose a latching structure with three locking grooves 21, 22, 23. Depending on the tilt position, the locking grooves 21 to 23 are partially hidden in the figures. In the illustrated embodiment, a trained as a slide actuator 43 (visible in FIGS. 4 and 5) is provided on the fork 41, which can engage in the locking grooves 21 to 23. The slider 43 is held by a provided in the fork 41, not visible in Fig. 1 to 5, spring in one of the locking grooves 21 to 23 by the spring force. To adjust the tilt position of the slider 43 is moved against the force of the spring by a user and locked in another locking groove 21 to 23.

As best seen in Figs. 4 and 5, the hinge assembly 4 further comprises an axis 44 about which the cutting head 2 relative to the guide shaft 3 between the trim position shown in FIGS. 1 to 3 and the edge cutting position shown in FIG. 4 pivotally has. The spar 42 is pivotable relative to the guide shaft 3 about the second axis 44. The guide stem 3 and the spar 42 have for this purpose mutually facing parallel surfaces, which lie in a plane shown schematically in Fig. 3 E, which is inclined relative to the guide stem 3. A longitudinal axis L of the guide stem preferably includes an angle β of approximately 135 ° with the plane E, as shown schematically in FIG. The second axis 44 is perpendicular to the plane E. In the arrangement shown in Fig. 3, the bar 42 and the guide stem 3 are coaxial. By pivoting about the second axis 44 of the spar 42 and thus the cutting head. 2 Angled relative to the guide shaft 3. 5 shows the pivoting process about the second axis 44. A pivoting about the second axis 44 is locked without the intervention of the user. To release the pivoting operation, an actuating element 45 is provided. The two possible relative positions between spar 42 and guide stem 3 are highlighted by optical means, such as arrows.

As can be seen in FIGS. 1 to 5, the illustrated wheel arrangement 5 is arranged pivotably about a pivot axis 50 on the guide shaft 3. The wheel assembly 5 comprises one or more struts 51, preferably two struts 51, wherein a free end of the struts 51, a roller, a wheel 52 or a plurality of rollers or wheels 52 are arranged. The struts 51 of the wheel assembly 5 are preferably arranged symmetrically to the guide shaft 3 and curved so that - as seen in Figure 5 - a pivoting about the second axis 44 is possible while the wheel assembly 5 is unfolded, i. gets up on the ground. This can increase the safety when pivoting.

In the illustrated embodiment, the safety and ease of use are increased by pivot locking means, by which a pivoting of the cutting head 2 is locked in the tilt positions shown in FIGS. 1 and 2 about the second axis 44 between the trim position and the edge cutting position. A pivoting about the second axis 44 is thus possible in the illustrated embodiment, only in the third tilt position shown in Fig. 3. In the illustrated embodiment, further pivoting of the cutting head 2 about the first axis 40 is blocked by the pivot locking means in the edge cutting position shown in Fig. 4. 6 and 7 show partially sectioned detail views of the pivot locking means according to the invention. As can be seen in FIG. 6, the latching grooves 21, 22 have a smaller depth than the latching groove 23. An end 430 of the slide 43 facing away from the latching grooves 21, 22, 23 blocks pivoting about the axis 44 when the slide 43 is locked in one of the locking grooves 21 or 22. Only when the slider 43 engages in the deeper locking groove 23, a pivoting about the second axis 44 is released. The slider 43 is loaded by a spring 46, which forces the slider in the locking grooves 21 to 23. To adjust the inclination of the slider 43 is moved against the force of the spring 46. However, the pivoting about the second axis 44 remains blocked even after the release by the slider 43, that is, after a positioning of the slider 43 in the third locking groove 23, so that use in the tilt position shown in Fig. 3 is possible.

For pivoting about the second axis 44 designed as a rocker 45 second actuator is provided. The rocker 45 is movable against the force of a second spring 47 by a user, so that a spring 47 facing away from the end 450 of the rocker 45 from a schematically indicated in Fig. 7 associated recess 421 on the spar 42 is guided. On the spar 42, two recesses 421 are provided in the illustrated embodiment, which allows latching of the rocker 45 in two relative positions between the bar 42 and the guide shaft 3.

According to the invention, therefore, a rotational adjustment for a vertical section (also referred to as edging function) can only be switched if the inclination is set such that the guide post 3 is in the horizontal position shown in FIG. As a result, unauthorized and / or unsafe working positions between the guide stem 3 and the cutting head 2 are prevented. The slider 43 is displaceable along a groove with a first groove portion 48a assigned to the spar 42 and a second groove portion 48b assigned to the guide stem 3 for changing the inclination position. In other words, the groove sections 48a, 48b are associated with two hinge parts pivotable about the axis 44 relative to each other. In the trim position shown in Fig. 6, the groove portions 48a, 48b are arranged in alignment. After pivoting about the axis 44, the groove portions 48a, 48b are not arranged in alignment. A displacement of the slider 43 is thereby blocked. This prevents that the cutting head 2 is pivoted relative to the fork 41 about the first axis 40, as long as the spar 42 is rotated relative to the guide stem 3, that is, the spar 42 and the guide stem 3 are not arranged in alignment.

By the fork 41 and the spar 42 guide forces applied in each working position by a user on a handle 30 are transmitted securely to the cutting head 2. A cable guide of a power cable 31 for a power supply of a motor arranged in the cutting head 2 is preferably as shown within the beam 42 and the fork 41 possible. In the handle 30 and / or in the spar 42 can not be provided for the power cable 31, not shown strain relief. On the Führungsgήff 3 is further provided in the illustrated embodiment, an additional handle 32 for better operation of the grass trimmer 1.

Claims

claims

A grass trimmer with a cutting head (2), a guide stem (3) and a joint arrangement (4), comprising a first (40) and. a second axis (44), wherein the cutting head (2) is pivotable relative to the guide shaft (3) about the first axis (40) between at least a first and a second tilt position and the cutting head (2) relative to the guide shaft (3) is pivotable about the second axis (44) between an edge cutting position and a trim position, characterized in that the hinge assembly (4) comprises pivot locking means by which in the first tilt position pivoting of the cutting head (2) about the second axis (44) between the Trimmstellung and the edge cutting position is locked and / or by which in the edge cutting position pivoting of the cutting head (2) about the first axis (40) is locked.

2. grass trimmer according to claim 1, characterized in that the first axis (40) is arranged substantially horizontally in a position of use.

3. grass trimmer according to claim 1 or 2, characterized in that the first and the second axis (40, 44) on the hinge assembly (4) in the direction of the guide stem (3) are arranged spaced, wherein the first axis (40) on a the guide post (3) facing away from the side and the second axis (44) on a guide stem (3) facing side is arranged.

4. grass trimmer according to one of claims 1 to 3, characterized in that the first axis (40) by a cutting head (2) encompassing, with the guide stem (3) operatively connected fork (41) is formed.

5. grass trimmer according to one of claims 1 to 4, characterized in that the pivot locking means comprise a first actuating element (43) which cooperates with a on the cutting head (2) provided latching structure (21, 22, 23) for determining a tilt position.

6. grass trimmer according to claim 5, characterized in that the first actuating element is loaded by a constraining element, in particular by a spring or the like.

7. grass trimmer according to claim 5 or 6, characterized in that the actuating element as a slide (43), rocker, lever or the like is formed.

8. grass trimmer according to claim 5, 6 or 7, characterized in that the actuating element (43) in the first inclination position with the latching structure (21, 22) such that the actuating element (43) prevents pivoting from the trim position in the edge cutting position ,

9. grass trimmer according to one of claims 5 to 8, characterized in that the actuating element (43) in a second inclined position such with the latching structure (23) latched, that the actuating element (43) free pivoting from the trim position in the edge cutting position gives.

10. grass trimmer according to one of claims 5 to 9, characterized in that the actuating element (43) at least partially in a groove with a first, the cutting head (2) associated portion (48 a) and a second, the guide stem (3) associated portion (48b), wherein the first and second portions are aligned in the trim position, such that the actuator (43) is slidable about the first axis (40) in the groove for pivoting, and the first and second portions are not aligned in the edge cutting position, so that a displacement, the actuating element (43) for pivoting about the first axis (40) is locked.

11. grass trimmer according to one of claims 1 to 10, characterized in that the second axis (44) with an axis of the guide stem (3) forms an angle in the range of about 30 ° to about 60 °, preferably about 45 ° ,

12. grass trimmer according to one of claims 1 to 1 1, characterized in that the second axis (44) is arranged coaxially to a central surface normal on two mutually sliding surfaces in a guide stem (3) intersecting inclined plane (E).

13. grass trimmer according to one of claims 1 to 12, characterized in that a second actuating element (45) is provided for fixing the trim position or the edge cutting position.

14. grass trimmer according to one of claims 1 to 13, characterized in that on the guide stem (3) has a wheel assembly (5) for a wheel support in the trim position and / or the Edge cutting position is arranged, in particular is arranged pivotably.

15. grass trimmer according to claim 14, characterized in that the wheel assembly (5) has at least one curved strut (50), wherein the curvature is designed so that the strut (50) in a use position outside a pivot radius of the cutting head (2) Adjustment about the first axis (40) and / or about the second axis (44) is arranged.