Rasentrimmer

Abstract

Portable lawn trimmer (1) comprising: a guide shaft (2), a cutting head (100) arranged at a first lower end (7) of the guide shaft (2) with a cutting tool (104) rotating about an axis of rotation (D) in a plane of rotation (E) within a surface of rotation (Fr) during operation, and a drive (105) for driving the cutting tool (104) about the axis of rotation (D), characterized in that the lawn trimmer (1) has a collection device (200) and the cutting head (100) has a protective hood (110), wherein the protective hood (110) encloses the cutting tool (104) rotating about the axis of rotation (D) in the plane of rotation (E) during operation from above, except for a through-opening (112), and the protective hood (110) and the cutting tool (104) are designed and arranged such that the cut produced by the cutting tool (104) during operation passes through the through-opening. (112) is conveyed in the protective hood (110) into the collection device (200),wherein the protective hood (110) and the cutting tool (104) are designed to cooperate with respect to an airflow in order to convey the cut through the through-opening (112).

Description

[0001] The invention relates to a portable grass trimmer according to the preamble of claim 1.

[0002] A grass trimmer is a portable, handheld garden tool that is operated without ground support (without rollers, wheels, etc.) via a guide handle and has one or more rotating cutting tools on its cutting head. These can include, for example, radially aligned blades or cutting blades or a cutting line.

[0003] The cutting head can be moved into various positions, including a trimming position and a vertical cutting position, also known as the edging position. A grass trimmer can generally be used to trim grass along the edges. A grass trimmer is typically used without contact with the ground, similar to a brush cutter.

[0004] It is an object of the invention to provide a portable grass trimmer which enables more comfortable operation, in particular with regard to the cut produced during operation.

[0005] According to one aspect, the present disclosure provides a grass trimmer that may include the following components: a guide bar and a cutting head disposed at a first lower end of the guide bar. The cutting head may include a cutting tool that rotates, during operation, about a rotational axis in a rotational plane within a rotational surface.

[0006] Furthermore, the grass trimmer can have a drive configured to rotate the cutting tool around the rotational axis (in a first direction of rotation) during operation (normal cutting operation). The drive can be arranged close to the cutting head, so that it can be considered a component of the cutting head. Alternatively, the drive can also be arranged higher up on the guide rod and drive the cutting tool via a corresponding mechanical coupling (shaft, etc.).

[0007] The drive can be an electric motor. It can also be an internal combustion engine.

[0008] A first handle may be provided, which is arranged at a second upper end of the guide shaft opposite the cutting head. Additionally, a second handle may be provided approximately in the middle of the guide shaft.

[0009] According to an advantageous aspect, the grass trimmer may have a collecting device for cuttings.

[0010] According to a further advantageous aspect, the cutting head can have a protective hood. With appropriate design, the protective hood can be advantageous with regard to conveying cuttings into a collecting device.

[0011] It is therefore advantageous to have a flow profile inside the protective hood which supports the transport of cuttings into the collecting device.

[0012] The through-hole can be arranged asymmetrically with respect to the cutting tool's rotational axis. This advantageously takes into account the fact that the cut has a particularly dynamic effect due to the movement / rotation of the cutting tool.

[0013] During operation, the cutting tool can rotate around the rotation axis in the rotation plane, for example in a first direction of rotation (normal cutting operation).

[0014] The surface swept by the cutting tool during rotation is referred to in this context as the surface of revolution. The surface of revolution lies in the plane of rotation.

[0015] Advantageously, the protective hood covers the rotating surface from above and protrudes at least slightly beyond the outer circumference of the rotating surface.

[0016] The protective hood advantageously covers at least a predominant portion, in particular at least 270°, of the outer circumference of the cutting tool rotating around the rotational axis during operation. In other words, the protective hood can advantageously extend around and enclose the rotating surface and be open only in the area of ​​the through-opening. Viewed from the outside, the cutting tool can be enclosed and protected by the protective hood from above and to the sides. The protective hood is only open downwards and in the area of ​​the through-opening.

[0017] Advantageously, the protective hood can generally be designed and arranged in such a way that the cut produced by the cutting tool during operation is conveyed through a through opening in the protective hood into the collecting device.

[0018] The protective hood can be formed in an area facing the collecting device in order to enable a detachable coupling of the collecting device.

[0019] For this purpose, the protective hood can, in particular, form a first adapter cross-section designed for releasably coupling a corresponding second adapter cross-section of the collecting device. The corresponding adapter cross-sections of the protective hood and the collecting device relate to the structural, physical design, which is coordinated with one another in such a way that, when the collecting device is coupled, the through-opening leads into the collecting device. In other words, when the collecting device is coupled, the interior of the collecting device communicates with the interior of the protective hood via the through-opening.

[0020] According to an advantageous aspect, at least one flow profile is formed within the protective hood by an inner contour, which is configured and arranged in such a way as to promote the movement of the cut into the collecting device. In this case, it has been taken into account that the cut does not easily pass from the interior of the protective hood through the through-opening into the collecting device. For this purpose, a suitable flow profile must advantageously be formed inside the protective hood, tailored to the type and operation of the cutting tool.

[0021] Advantageously, the inner contour, which serves to form the flow profile, can be arranged in a region facing the collecting device and spaced apart from an outer contour of the protective hood. For example, the protective hood can have an outer wall and one or more inner walls and contours, which then form the inner contour and thus generate the flow profile.

[0022] According to one aspect, the inner contour can be designed in the manner of a shaft and can support the feeding of the cut produced during operation to the through opening.

[0023] The inner contour can be formed by one or more inner walls.

[0024] The shaft can taper from the cutting tool toward the through hole and narrow over time. It can initially be wider, i.e., closer to the cutting tool, than near the through hole. The width of the shaft refers to a dimension in the plane of rotation.

[0025] The inner contour can advantageously have a lower guide, in particular a plate, which at least partially covers the area covered by the protective hood from above, outside the rotation surface in the area of ​​the through opening, and closes it off at the bottom. This prevents any cutting action from being lost downwards.

[0026] The inner contour may have a first profile on a first side of the through-opening which is configured differently than a second profile on a second side of the through-opening, wherein the first side is arranged in front of the through-opening and the second side is arranged after the through-opening with respect to the direction of rotation of the cutting tool.

[0027] The first profile can be designed such that it follows the circumference of the cutting tool rotating about the rotation axis during operation for a longer time than the second profile, wherein in particular the first profile runs flatter (tangentially) with respect to the circumference of the rotating cutting tool than the second profile, so that the cut produced by the cutting tool is guided by the first profile for a longer time than by the second profile and is guided by the second profile at a steeper angle (steeper than the angle of the first profile) onto the through opening.

[0028] Advantageously, the protective hood and the cutting tool can be configured to cooperate to convey the cut through the through-opening. The cutting tool and the protective hood can be configured to cooperate with respect to an air flow to convey the cut.

[0029] The cutting tool can be designed geometrically, in particular fluidically, to convey the cut material to the collecting device.

[0030] The cutting tool, in particular at least one cutting blade of the cutting tool, can be designed to cause an air flow into the protective hood during operation.

[0031] During operation, the cutting blade can create a negative pressure (or suction) that sucks the cut material into the protective hood.

[0032] The air flow generated by the cutting tool during operation can advantageously be redirected by the protective hood and diverted / deflected in the direction of the through opening.

[0033] The cutting tool, in particular the cutting blade, can be structurally and geometrically designed to generate the air flow or suction or negative pressure.

[0034] According to one aspect, the cutting tool can be two-part. Alternatively, the cutting tool can also be a single-piece design. A two-piece design has two physically separate cutting blades. These can be replaced separately, which can reduce spare parts costs.

[0035] The cutting tool can advantageously have at least one flow element. The flow element can optimize the behavior of the cutting tool and the cut. The cutting blade can have at least one angled portion / part that forms the flow element. The cutting blade can advantageously comprise a first portion that is narrower (less wide) than a second portion, whereby the second portion can be located further outward radially (relative to the rotation axis). The second portion can then comprise the angled portion.

[0036] Advantageously, the cutting blade can have a cutting edge and the at least one flow element can be arranged on a side of the cutting blade opposite the cutting edge.

[0037] The flow element can be designed to generate the air flow during operation. This air flow can be directed into the protective hood. The flow element can be configured to create a negative pressure or suction that draws the cut material into the protective hood.

[0038] If the cutting tool has two cutting blades (regardless of whether it is one-piece or two-piece), a flow element can be arranged on each cutting blade.

[0039] The weight of a cutting knife, in particular of a part or blade of a cutting knife, can advantageously not exceed 10 g, advantageously not exceed 5 g, in particular not exceed 3 g. It can advantageously be in the range of 2.2 g.

[0040] The cutting tool can be made of metal. Advantageously, the cutting tool, and in particular the cutting blade, comprises a plastic or is made entirely of this plastic.

[0041] The plastic used for the cutting blade can be, for example, polyphenylene sulfide (with 40% glass fiber content (PPS GF40). It can also be polyoxymethylene (POM), also known as acetal. Polycarbonate (PC) is also a possibility.

[0042] However, it is particularly advantageous for the cutting tool, especially the cutting blade, to be made partly or entirely of polyamide (PA), also known as nylon. The polyamide can advantageously contain a glass fiber content.

[0043] Particularly advantageously, the cutting blade or cutting tool is made of polyamide with a glass fiber content of more than 10%, in particular with a glass fiber content of about one third (33% / 34%), ie it can be PA66 (66% polyamide with about 33% glass fiber).

[0044] The grass trimmer can advantageously be exclusively portable or designed for portable use and not have any features that carry it across the area to be trimmed, such as wheels or rollers. The grass trimmer can therefore be roller-free.

[0045] The weight (total weight without filling the collecting device) of the grass trimmer can be less than 10 kg, advantageously less than 5 kg, advantageously less than 2 kg, in particular approx. 1.5 kg.

[0046] The grass trimmer can be set up to have a runtime (working time) of 25 minutes in battery operation at a speed of 800 rpm (revolutions per minute, controllable if necessary). The runtime can be approximately 30 minutes without load. The noise level during operation can reach 78 dB at a distance of one meter. The grass trimmer can advantageously be operated with a voltage above 3 V, preferably above 5 V, or preferably above 10 V. 11.2 V or more is particularly advantageous. The battery can have a capacity of 2000 mAh, for example, and a charging output of 12 V and 500 mA. It can be a lithium-ion battery. The grass trimmer can advantageously be operated exclusively with batteries (no mains operation).

[0047] According to one aspect, the collecting device can be adjustable. The collecting device can be configured as a bag.

[0048] The collecting device can be adjustably fastened to the guide handle with a side facing away from the protective hood, in particular by means of a cord, a rope, a thread, a line, a rope or the like.

[0049] The collecting device can be coupled and released from the cutting head or the protective hood using a button.

[0050] A closure element or flap can be provided that covers or closes the passage opening, preferably automatically, when the collecting device is removed. The flap can be spring-loaded (force is applied and closes the flap when the collecting device is removed).

[0051] The present disclosure also provides a portable (roller-free) gardening device or a portable (roller-free) gardening tool having a cutting head with a cutting tool. The cutting head and / or the cutting tool are advantageously configured according to the aspects and features described herein.

[0052] The present disclosure also provides a portable (roller-free) motorized gardening device or garden tool, in particular an electrically powered portable (roller-free) gardening device or garden tool, comprising a protective hood and / or a cutting tool according to the features and aspects of the present disclosure.

[0053] The present disclosure also provides a portable (reel-free) brush cutter having a cutting head with a cutting tool. The cutting head and / or the cutting tool are advantageously configured according to the aspects and features described herein.

[0054] The present disclosure also provides a motorized portable (reel-free) brush cutter, in particular an electrically powered brush cutter, having a protective hood and / or a cutting tool according to the features and aspects of the present disclosure.

[0055] In particular, the aforementioned portable (roller-free) gardening devices, garden tools and / or brush cutters can have a cutting tool, in particular a cutting blade, which consists essentially of plastic. The plastic of the cutting blade can be, for example, polyamide with a glass fiber content of more than 10%, in particular with a glass fiber content of approximately one third (33% / 34%), i.e. it can be PA66 (66% polyamide with approximately 33% glass fiber). A protective hood can be provided which encloses the cutting tool / cutting blade except for a through opening to a collecting device and is only open at the bottom. The cutting blade can interact fluidically with the protective hood to create suction (negative pressure) below the protective hood and to transport the cuttings (e.g. grass clippings) from below and inside the protective hood through the through opening into the collecting device.For this purpose, the cutting tool / cutting blade can have a flow element (wing). Further features and aspects will become apparent from the present disclosure.

[0056] Further features and aspects of the invention will become apparent from the following description of embodiments with reference to the following attached figures: Fig. 1 is a simplified schematic perspective view of a grass trimmer from the side from above according to an embodiment, Fig. 2 is a simplified schematic perspective view of a grass trimmer from below according to an embodiment, Fig. 3 is a simplified schematic perspective view of a grass trimmer from the side according to an embodiment, Fig. 4 is a simplified schematic plan view of the insulated cutting tool in the cutting head, Fig. 5 is a simplified schematic side view of the insulated cutting tool, Fig. 6 is a simplified schematic plan view of a blade of the cutting knife, Fig. 7 is a simplified schematic cross-section of the cutting blade with wing, Fig. 8 is a simplified side view of the Fig. 3 (side view) with transparent protective cover, Fig. 9 is a simplified perspective section of a view of the cutting head from below, Fig. 10 is a simplified perspective section of a view of the cutting head from below, Fig. 11 is a simplified perspective cross-section of a view of the cutting head from below Fig. Figure 12 is a simplified perspective view of the cutting head from the direction of the catcher, the catcher not being shown, and Fig. Figure 13 is a simplified perspective view from the direction of the cutting head of the transition area between the cutting head and the collecting device, with most parts of the cutting head not shown.

[0057] The Fig. 1 to 13 show different views of an embodiment of a grass trimmer 1 according to the present disclosure.

[0058] The Fig. 1, Fig. 2 and Fig. 3 show perspective side views with different inclinations. The grass trimmer 1 comprises a guide handle 2 and a cutting head 100 arranged at a first lower end 7 of the guide handle 2.

[0059] The cutting head 100 can be coupled to the guide shaft 2 by means of a joint arrangement 10. This allows the cutting head 100 to be adjustably coupled to the guide shaft 2.

[0060] The cutting head 100 has a cutting tool 104 that rotates during operation. Furthermore, the grass trimmer 1 can have a drive 105 that is configured to rotate the cutting tool 104 during operation—which is to be understood here as normal cutting operation—about the rotational axis D in a (first) rotational direction DR (see FIG. Fig. 2). The drive 105 can be arranged close to the cutting head 100, so that it can be considered a component of the cutting head 100. In other embodiments, the drive 105 can also be arranged higher up on the guide rod 2 and drive the cutting tool 104 via a corresponding mechanical coupling, such as a shaft, gears, etc.

[0061] In the present embodiment, the drive 105 is an electric motor. Alternatively, the drive 105 can be an internal combustion engine.

[0062] A first handle 6 may be provided, which is arranged at a second upper end 8 of the guide shaft 2 opposite the cutting head 100. Additionally, a second handle 9 may be provided approximately in the middle of the guide shaft 2.

[0063] The grass trimmer 1 has a collecting device 200 designed to collect the cut produced by the cutting tool. The cutting head 100 has a protective hood 110. According to this exemplary embodiment, the collecting device 200 is adjustable. For this purpose, the collecting device 200 is adjustably and detachably attached to the guide handle 2 with a side 203 facing away from the protective hood 100. For this purpose, a line 201 (also cord, rope, thread, rope, or the like) is provided, which is attached to the rear end 203 of the collecting device 200 on the one hand and to a hook 204 in the area of ​​the first handle 6 on the other hand on the guide handle 2. The line 201 also has an adjustment mechanism 205, by means of which the line can be flexibly shortened or lengthened. This can be realized, for example, by a clamping element 205 through which a loop of the line 201 can be pulled.

[0064] The collecting device 200 can be coupled to and released from the cutting head 100 or the protective hood 110 by means of an actuating element, such as a button 111. The actuating element 111 can have return elements in the form of springs or the like. The actuating element 111 is attached to the collecting device 200.

[0065] A closure element or closure flap 116 may be provided, which automatically covers or closes the passage opening 112 when the collecting device 200 is removed. The closure flap 116 may be spring-loaded (force is applied and closes the flap when the collecting device 200 is removed). This also supports operation, for example, on wet lawns and protects the user.

[0066] The collecting device 200 can be designed as a more or less elastic or flexible bag. The collecting device 200 can taper toward the rear end 203 and be openable at the rear.

[0067] The Fig. 4 to 7 relate to the cutting tool 104 and the cutting blade 114, respectively, and show details of the cutting tool 104 and the cutting blade 114, respectively.

[0068] The protective hood 110 and the cutting tool 104 are configured to cooperate to convey the clippings through the through-opening 112. More specifically, the cutting tool 104 and the protective hood 112 are configured to cooperate with respect to an air flow through which the grass clippings produced by the cutting blade 114 are conveyed through the through-opening 112 into the collecting device 200. The cutting tool 104 is geometrically, in particular fluidically, configured to convey the clippings to the collecting device 200.

[0069] The cutting tool 104, in particular a cutting blade 114, of the cutting tool 104 generates an air flow into the protective hood 110 during operation. In other words, the cutting blade 104 generates a negative pressure or suction during operation, which draws the cut material into the protective hood 110. The air flow (negative pressure, suction) generated by the cutting tool 104 during operation is deflected by the protective hood 110 and diverted / deflected toward the through-opening 112. The cutting tool 104, in particular the cutting blade, is structurally and geometrically designed to generate the air flow or suction or negative pressure.

[0070] According to one aspect, the cutting tool 104 can be a two-part assembly. Alternatively, the cutting tool 104 can also be a single-part assembly. In a two-part configuration, for example, there are two parts 114-1, 114-2 of the cutting blade 114. These can be replaced separately, which can reduce spare part costs.

[0071] The cutting blade 114, or the parts / blades 114-1, 114-2, has an angled portion / part or widening (also called a wing or flow element) 107. In the area of ​​the angled portion 107, the cutting blade 114 is wider than radially further inward (relative to the rotation axis).

[0072] The weight of a cutting knife 114, in particular a part or a blade 114-1, 114-2 of a cutting knife, is not greater than 10 g, advantageously not greater than 5 g, not greater than 3 g. It can advantageously be in the range of 2.2 g.

[0073] The cutting tool can be made of metal. Advantageously, the cutting blade 114 comprises a plastic or is made entirely of this plastic.

[0074] The plastic used for the cutting blade can be, for example, polyphenylene sulfide (with 40% glass fiber content (PPS GF40). It can also be polyoxymethylene (POM), also known as acetal. Polycarbonate (PC) is also an option. However, polyamide (PA), also known as nylon, can be used with particular advantage. The polyamide can advantageously contain a glass fiber content.

[0075] It is particularly advantageous for the cutting blade or cutting tool to be made of polyamide with a glass fiber content of more than 10%, especially with a glass fiber content of 33%, i.e., it can be PA66 (66% polyamide with 33% glass fiber). It is advantageous to use approximately two-thirds polyamide and one-third glass fiber.

[0076] The Fig. 4 and Fig. 5 show two simplified schematic representations of the cutting tool 104, which is shown here in isolation. Fig. 4 shows the cutting tool from above. Fig. 5 shows the cutting tool 104 from the side.

[0077] Out of Fig. 4 shows that the cutting tool 104 has a cutting blade 114, which during operation rotates about the rotation axis D in the rotation plane E, for example, in a first rotation direction DR (normal cutting operation). The surface swept over by the cutting tool 104 or cutting blade 1114 during rotation is referred to in the present context as the rotation surface Fr. The rotation surface Fr lies in the plane E.

[0078] The cutting tool 104 or cutting blade 114 has two parts 114-1, 114-2, i.e., it is composed of two parts. These are a first cutting blade 114-1 and a second cutting blade 114-2. The advantage of a two-part design is that only a single cutting blade 114-1, 114-2 needs to be replaced if it becomes damaged.

[0079] For better orientation, the Cartesian directions X, Y, and Z are shown in the figures. However, these serve only as a rough guide and are not to be understood with complete precision. The rotation plane E and thus also the surface of rotation Fr lie approximately in the ZY plane. The rotation axis D extends approximately along the X direction.

[0080] Fig. 6 is a simplified schematic plan view of a first part or second part or a first or second blade 114-1 or 114-2 of the cutting knife 114 or cutting tool 104. This view serves, among other things, to describe the size relationships. The cutting knife 114, or its blade 114-1, 114-2, comprises a first region 119 which is essentially flat and has the cutting edge 106 over almost the entire length FL1. It comprises a second, angled region 107, which is also referred to as a flow element 107 or a vane 107. The cutting knife 114, or its blade 114-1, 114-2, has a first width FB1 and, radially further outward in the region of the vane 107, a second width FB2. The second width FB2 is greater than the first width FB1. The ratio FB2 / FB1 can be 1.5. In particular, the first width FB1 can be approximately 10 mm and the second width FB2 can be 15 mm. The length FL1 of a blade orof a part 114-1, 114-2 of a cutting blade 114 can be between 80 mm and 100 mm, advantageously approximately 90 mm. The length FL2 of the wide section (which includes the wing 107) can be between 30 mm and 50 mm, advantageously approximately 40 mm.

[0081] The flow element 107 can also taper slightly with increasing distance from the cutting edge 106, which is indicated by a shortened second length FL2x. This can result in aerodynamic improvements.

[0082] The cutting blade 114 or each part 114-1, 114-2 has its own coupling area 118 with which it can be coupled to the drive (e.g. coupling element 115).

[0083] Fig. Figure 7 is a simplified schematic cross-section of the cutting blade 114 with the angled portion or wing 107. The second width FB2 is shown again here. As can be seen, there is an angle α between the blade and the wing 107. This angle is located on the side of the cutting blade pointing inwards, into the protective hood 110, and is significantly less than 180°; advantageously, it is approximately between 110° and 150°, and preferably approximately 135° or 137°. The angled portion or wing 107 results in a height FH2 of approximately 5 mm. The thickness FD of the blade 119 and the wing can be less than 1 mm, in particular 0.4 mm. The wing 107 causes an air flow (or negative pressure, suction beneath the protective hood) into the protective hood 110. The protective hood 110 is designed internally in such a way that this air flow is then directed through the through opening 112 into the collecting device 200.

[0084] The flow element 107, or the blade, is shown here as a simplified, straight line. However, it can and usually will have a curved cross-sectional profile, as shown by the dashed lines. This can further improve the airflow (suction beneath the protective hood).

[0085] Fig. 8 is a simplified side view of the Fig. 3 (side view), where the protective cover 110 is transparent for better display of the details. Fig. 8 and the Fig. 4 and Fig. 5 that the protective hood 110 covers the rotational surface Fr from above and also covers the outer circumference U of the rotational surface Fr all the way around. The protective hood 110 can cover at least a predominant part, in particular at least 270°, of an outer circumference U of the cutting tool 104 rotating about the rotational axis D during operation. The protective hood 110 thus extends around the rotational surface Fr and encloses the circumference U or the rotational surface. Strictly speaking, it is not so much a rotational surface Fr but rather a circular-cylindrical rotational body or a circular-cylindrical rotational volume Vr that encompasses the area in which the cutting tool 104 moves during rotation. For the sake of simplicity, this is referred to as the rotational surface Fr. The protective hood 110 encloses the end face (which would then be Fr) and the lateral surface of this rotational volume.

[0086] The cutting tool 104 has at least one flow element 107, whereby in this example two cutting blades 114-1, 114-2 are shown, each with a flow element 107. The flow elements 107 create a suction that sucks the cut material into the protective hood.

[0087] The cutting tool 104 or each cutting blade 105 has a cutting edge 106, with each flow element 107 arranged on a side of the cutting blade 105 opposite the cutting edge 106. The flow elements 107 are designed as a type of angled wings 107 that generate negative pressure beneath the device, which draws the grass clippings toward the protective hood.

[0088] Fig. Figure 9 is a simplified perspective section of a view of the cutting head 100 from an oblique bottom view. From this perspective, the through-opening 112 can be seen, which connects the working area (i.e., the rotational surface Fr) of the cutting tool 104 covered by the protective hood 110 with the interior space 202 of the collecting device 200.

[0089] The protective hood 110 can in principle be designed and arranged in such a way that the cut produced by the cutting tool 104 during operation is conveyed through the through opening 112 in the protective hood 110 into the collecting device 200.

[0090] In Fig. 9 it can be seen that the through-opening 112 is arranged laterally offset, ie it is arranged asymmetrically with respect to the rotational axis D. In other words, the through-opening 112 is displaced with respect to the rotational axis D in the direction of rotation DR or along the Z-axis. This can also be seen in the Fig. 10 and Fig. 11, which are described below.

[0091] Fig. Figure 10 is a simplified perspective view of the cutting head 100 from below. From this figure, as well as from the Fig. 1 to 3 and 6 show that the collecting device 200 is coupled to the cutting head 100 in a special way. For this purpose, the protective hood 110 is formed in an area facing the collecting device 200 to enable a detachable coupling of the collecting device 200.

[0092] From the Fig. Further details can be found in chapters 9 to 11. Fig. 11 is a simplified perspective cross-sectional view of the cutting head 100 taken obliquely from below. Fig. 12 is a simplified perspective view of the cutting head from the direction of the catcher, the catcher not being shown. Fig. 13 shows, among other things, the Fig. 12 opposite direction. Fig. 13 is a simplified perspective view from the direction of the cutting head 100 of the transition area between the cutting head 100 and the collecting device 200, with most parts of the cutting head 100 not shown.

[0093] In particular from the Fig. 10 and Fig. 11 shows that the protective hood 110 forms a first adapter cross-section Q1, which is designed for the detachable coupling of a corresponding second adapter cross-section Q2 of the collecting device 200. The corresponding adapter cross-sections Q1, Q2 of the protective hood 110 and the collecting device 200 relate to the structural, physical design, which is coordinated with one another such that, when the collecting device 200 is coupled, the through-opening 112 leads into the collecting device. In other words, when the collecting device 200 is coupled, the interior of the collecting device 200 communicates (with respect to air flow and the transport of cuttings) with the interior of the protective hood 110 via the through-opening 112.

[0094] As in particular the Fig. 8, Fig. 9 and Fig. As can be seen from Figure 11, a flow profile is formed within the protective hood 110 by an inner contour Ki. This inner contour Ki is configured and arranged in such a way that the movement of the cut into the collecting device 200 is promoted. In doing so, it has been taken into account that the cut does not easily pass from the interior of the protective hood 110 through the through-opening 112 into the collecting device 200. For this purpose, a suitable flow profile tailored to the type and operation of the cutting tool 104 must advantageously be formed inside the protective hood 110.

[0095] The inner contour Ki is advantageously adapted to the cutting tool 104 and interacts synergistically with it. During operation, the cutting tool 104 or cutting blade 114 generates a negative pressure or suction, which initially draws the cut material into the protective hood 110. There, the flow profile of the inner contour Ki of the protective hood 110 guides the cut material toward and through the collecting device or through-opening 112.

[0096] Advantageously, the inner contour Ki, which serves to form the flow profile, can be arranged in an area facing the collecting device 200 and can be delimited by an outer contour Ka (cf. e.g. Fig. 1, Fig. 9, 10, 11) of the protective hood 110. For example, the protective hood 110 may have one or more outer walls that form the contour Ka and one or more inner walls that then form the inner contour Ki and thus generate the flow profile.

[0097] In other designs, Ka and Ki may also be identical. For example, the inner contour Ki may determine the outer contour Ka.

[0098] The inner contour Ki is advantageously designed in the manner of a shaft. Due to its specific shape, this shaft supports the feeding of the cut produced during operation to the through-opening 112 and into the collecting device 200. For this purpose, the inner contour Ki is formed by one or—as in the present example—several inner walls.

[0099] The shaft runs from the cutting tool 104 toward the through-opening 112 and becomes narrower over time. Initially, i.e., closer to the cutting tool 104, it may be wider than near the through-opening 112. The width of the shaft refers to a dimension Z in the rotation plane E, specifically the dimension Z.

[0100] The inner contour Ki has a lower guide 108, which is designed like a base plate. This base plate closes off the area between the cutting tool and the through opening 112. This prevents any cutting material from being lost downwards.

[0101] The inner contour Ki has a first profile P1 and a second profile P2. The first profile P1 is arranged on a first side S1 of the through-opening 112. The first profile P1 is designed differently than the second profile P2. The second profile is arranged on a second side S2 of the through-opening 112. The first side S1 or the first profile P1 is arranged upstream of the through-opening 112 with respect to the direction of rotation DR of the cutting tool 104, and the second side S2 or the second profile P2 is arranged downstream of the through-opening 112 with respect to the direction of rotation DR of the cutting tool 104.

[0102] The first profile P1 is designed in such a way that it corresponds to the circumference U (cf. Fig. 4) of the cutting tool 104 rotating around the rotational axis during operation, for a longer time than the second profile P2, wherein, in particular, the first profile P1 runs longer and flatter tangentially (along the circumference U) relative to the circumference U of the rotating cutting tool 104 than the second profile P2. This means that the cut produced by the cutting tool 104 is guided by the first profile P1 for a longer time than by the second profile P2 and is guided by the second profile at a steeper angle to the through-opening 112. This asymmetry between the two profiles P1, P2 significantly supports the supply of cut material to the through-opening 112.

[0103] The grass trimmer 1 can advantageously be exclusively portable or designed for portable use and not have any devices that carry it over the area to be trimmed, such as wheels or rollers. The grass trimmer 1 can therefore be roller-free.

[0104] The weight (total weight without filling the collecting device (200)) of the grass trimmer 1 is not greater than 10 kg, in particular not greater than 5 kg, in particular not greater than 2 kg, in particular not greater than or approximately 1.5 kg.

[0105] The grass trimmer 1 is designed to have a running time (working time) of 25 minutes in battery operation at a speed of 800 rpm (controllable if necessary). The running time (working time) can be approximately 30 minutes without load. The noise level during operation is approximately 78 dB at a distance of one meter. The operating voltage is approximately 11.2 V. The battery has a capacity of 2000 mAh and a charging output of 12 V and 500 mA. It is a Li-ion battery. The grass trimmer 1 is advantageously exclusively battery-operated (no mains operation). List of reference symbols 1 lawn trimmer 2 guide handle 6 First step 7 First lower end of the guide rod 8 Second upper end of the guide rod 9 Second handle 10 Joint arrangement between cutting head and guide rod 100 cutting head 104 Cutting tool 105 Drive 106 cutting edge 107 Flow element, blade on cutting blade, angled part 108 Base plate, lower guide 110 Protective cover 111 Button, actuating device 112 passage opening 114 cutting blades 114-1 First part / blade of the cutting knife (also cutting knife) 114-2 Second part / blade of the cutting knife (also cutting knife) 115 Coupling element for coupling to drive / shaft of drive 116 Closure element, closure flap 118 Coupling area of ​​the cutting blade 119 First area of ​​the cutting knife with cutting edge 200 collecting device 201 Adjustable tether 202 Interior of the collecting device 203 Far side / far end of the fall arrest device 204 hooks for hooking the fall arrester to the guide handle 205 Adjustment mechanism for (e.g. retaining line of) fall arrest device α (Summary) angle between wing 107 and cutting knife blade 114- 1, 114-2 (preferably < 180°) D axis of rotation DR Direction of rotation of cutting tool in cutting operation E Rotation plane of the rotating cutting tool Fr Rotational surface of the cutting tool in the rotational plane E Vr Rotation volume of the cutting tool U Outer circumference of the rotating cutting tool Ki Inner contour of the protective hood Ka Outer contour of the protective hood P1 First profile (flow profile) P2 Second profile (flow profile) S1 First Page S2 Second side (in direction of rotation DR to first side) Q1 First adapter cross-section Q2 Second adapter cross-section X, Y, Z Cartesian coordinates FB1 Width of the first section of the cutting blade FB2 Width of the second section of the cutting blade FL1 Total length of the cutting blade FL2 (inner if applicable) length of the flow element (e.g. FL2 smaller than FL1) FL2x Shortened outer length of the flow element 107 FD Thickness / strength of the cutting blade

Claims

[1] Portable grass trimmer (1) comprising: a guide handle (2), a cutting head (100) arranged at a first lower end (7) of the guide handle (2) with a cutting tool (104) rotating in operation about an axis of rotation (D) in a plane of rotation (E) within a surface of rotation (Fr), and a drive (105) for driving the cutting tool (104) about the axis of rotation (D), characterized byin that the grass trimmer (1) has a collecting device (200) and the cutting head (100) has a protective hood (110), wherein the protective hood (110) encloses the cutting tool (104), which rotates during operation about the axis of rotation (D) in the plane of rotation (E), from above up to a through-opening (112), and the protective hood (110) and the cutting tool (104) are designed and arranged such that cut material produced by the cutting tool (104) during operation is conveyed through the through-opening (112) in the protective hood (110) into the collecting device (200), wherein the protective hood (110) and the cutting tool (104) are designed to cooperate with respect to an air flow in order to convey the cut material through the through-opening (112). [2] Grass trimmer (1) according to claim 1, wherein the protective hood covers a rotational surface (Fr) of the cutting tool (104) from above and at least to a predominant part, in particular except for the through opening (112), encloses an outer circumference (U) of the cutting tool (104) rotating about the rotational axis (D) during operation. [3] Grass trimmer (1) according to one of the preceding claims, wherein the cutting tool (104) comprises a cutting blade (114), the cutting blade (114) having two separate parts (114-1, 114-2). [4] Grass trimmer (1) according to claim 3, wherein the cutting blade (114, 114-1, 114-2) is geometrically, in particular fluidically, arranged to cause a suction or negative pressure in the protective hood (110). [5] Grass trimmer (1) according to claim 4, wherein the cutting blade has a flow element (107) by which the air flow in the form of a suction or negative pressure is effected into the protective hood (110). [6] Grass trimmer (1) according to claim 5, wherein the flow element (107) is formed by an angled portion / part of the cutting blade (114, 114-1, 114-2). [7] Grass trimmer (1) according to claim 5 or 6, wherein the cutting blade (114, 114-1, 114-2) has a cutting edge (106) and the at least one flow element (107) is arranged on a side of the cutting blade (114, 114-1, 114-2) opposite the cutting edge (106). [8] Grass trimmer (1) according to one of claims 3 to 7, wherein the weight of a cutting blade (114, 114-1, 114-2) is not greater than 10 g, advantageously not greater than 5 g, advantageously not greater than 3 g, advantageously about 2.2 g. [9] Grass trimmer (1) according to one of claims 3 to 8, wherein the cutting blade (114, 114-1, 114-2) comprises a plastic, in particular optionally consists entirely of plastic. [10] Grass trimmer (1) according to claim 9, wherein the plastic is polyamide (PA) with a proportion of glass fiber (GF), in particular wherein the plastic comprises two thirds PA and one third GF (PA66). [11] Grass trimmer (1) according to one of claims 3 to 10, wherein the air flow generated by the cutting blade (114, 114-1, 114-2) during operation is diverted from the protective hood (110) in the direction of the through opening (112). [12] Grass trimmer (1) according to claim 11, wherein an inner contour (Ki) is formed inside the protective hood (110), which is designed and arranged in such a way that the movement of the cut into the collecting device (200) is promoted. [13] Grass trimmer (1) according to claim 12, wherein the inner contour (Ki) is arranged in a region facing the collecting device (200) and is spaced from an outer contour (Ka) of the protective hood (110), wherein the inner contour (Ki) is designed in the manner of a shaft and supports a feeding of the cut produced during operation to the through opening (112). [14] Grass trimmer (1) according to claim 12 or 13, wherein the inner contour (Ki) has a lower guide, in particular a plate, which closes off the area covered by the protective hood (110) outside the rotation surface (Fr) in the area of ​​the through opening (112) downwards. [15] Grass trimmer (1) according to one of claims 12 to 14, wherein the inner contour (Ki) has a first profile (P1) on a first side (S1) of the through-opening (112), and a second profile (P2) on a second side (S2) of the through-opening (112), wherein the first side (S1) is arranged in front of the through-opening (112) and the second side is arranged after the through-opening (112) with respect to the direction of rotation of the cutting tool (104), and wherein the first profile (P1) follows the circumference of the cutting tool rotating about the axis of rotation during operation for a longer time than the second profile (P2), wherein in particular the first profile is flatter with respect to the circumference (U) of the rotating cutting tool (104) than the second profile (P2). [16] Grass trimmer (1) according to one of the preceding claims, wherein the through-opening (112) is arranged asymmetrically with respect to the axis of rotation (D) of the cutting tool (104), in particular a connecting surface of the collecting device is displaced from a center in the direction of rotation (DR). [17] Grass trimmer (1) according to one of the preceding claims, wherein the grass trimmer (1) is roller-free. [18] Grass trimmer (1) according to one of the preceding claims, wherein the collecting device (200) is adjustable [19] Grass trimmer (1) according to one of the preceding claims, wherein the collecting device (200) is designed as a bag. [20] Grass trimmer (1) according to one of the preceding claims, wherein the collecting device is adjustably fastened to the guide handle (2) with a side facing away from the protective hood (110), in particular by an adjustable cord. [21] Grass trimmer (1) according to one of the preceding claims, wherein the protective hood (110) is designed in a region facing the collecting device (200) to form a detachable coupling of the collecting device (200), in particular a first adapter cross-section (Q1) which is designed for detachable coupling of a corresponding second adapter cross-section (Q2) of the collecting device (200), so that the through-opening (112) leads into the collecting device and is in communication with the interior of the collecting device (200). [22] Grass trimmer according to claim (1), wherein the grass trimmer (1), in particular the collecting device (200) has an actuating device (111) which is designed to couple the collecting device (200) to the cutting head (100) and to release it again therefrom. [23] Grass trimmer according to one of the preceding claims, wherein it comprises a closure element (116), in particular a closure flap (116), which is designed to close the through opening (112), in particular automatically, when the collecting device (200) is removed from the protective hood.

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