Cutter, in particular grass cutter, preferably lawn edge cutter

Abstract

The invention relates to a cutter, in particular grass cutter, preferably lawn edge cutter, with at least one cutting device having a blade arrangement comprising at least one lower blade and at least one upper blade, which are movable, preferably in oscillating manner, relative to one other, wherein the at least one upper blade has at least one first upper blade and one second upper blade. The invention is characterized in that the cutter has a drive unit preferably in the form of an electric motor for the first upper blade and the second upper blade, and the drive unit is a common drive unit for at least the first upper blade and the second upper blade, and the drive unit comprises at least three gearwheels, wherein the three gearwheels comprise two gearwheels which are substantially equal in size, in particular with a substantially identical diameter, a first gearwheel and a second gearwheel each having an eccentric disc, and a third, central gearwheel is formed in order to engage in the first gearwheel and the second gearwheel (540), wherein the central, third gearwheel is connected to a pinion of the electric motor.

Description

[0001] Cutting device, especially grass cutting device, preferably lawn edge trimmer

[0002] The invention relates to a cutting device, in particular a grass cutting device, preferably a lawn edge cutting device.

[0003] The cutting device according to the invention is a cutting device such as those used for mowing grass. Cutting devices operating according to the scissor principle as mowing devices can be divided into scythe mowers and grass shears according to the state of the art.

[0004] Scythe mowers have translatory oscillating blades. In contrast, grass shears have blades that oscillate around a pivot point.

[0005] A rotary oscillating system as a grass shear is shown, for example, in US 3623223 A. The system shown in US 3623223 A consists of a fixed lower blade and a rotary oscillating upper blade.

[0006] The upper blade is driven by an eccentric disc, which is preferably directly connected to the electric motor via a shaft.

[0007] Scythe mowers are primarily used in agriculture for larger cutting widths. The scythe mower known from EP 2853142 A1 has double-sided blade bars. WO 1999 / 07202 A describes a hand-held, portable scythe mower with a single-sided blade bar. These scythe mower blade bars have cutting widths ranging from approximately 500 mm to several meters.

[0008] As an alternative to scythe mowers, grass shears can also be used for cutting grass. The advantage of grass shears is their simple design and the resulting low power loss due to minimized friction. This is particularly evident in the longer running time of battery-operated devices. The disadvantage of grass shears, however, is that they are limited in cutting width and are only suitable for narrow strips of grass that cannot be caught at the edges when mowing areas with conventional lawn mowers and thus remain standing. Larger cutting widths with grass shears can only be achieved, as shown in EP 1886551 A1, by stringing together several grass shear blades, for example two. EP 1886551 A1 does not provide any information on the drive of the two grass shear blades, which are also referred to as the upper blades.

[0009] In recent years, robotic lawnmowers have become increasingly popular, particularly in allotment gardens. Robotic lawnmowers autonomously move to a defined area to cut grass, following random or specific patterns. In peripheral areas, especially in front of walls or house facades, this usually leaves strips of grass at least 200 mm wide that cannot be cut. However, such edge strips are too wide for the use of lawn edge trimmers. Such an area can then only be cut with lawn shears in several passes.

[0010] US 3973378 shows a system with four rotating oscillating upper blades on a fixed lower blade with sufficient width for cutting the edges of grass. The device is particularly suitable for small areas. In US 3973378, two blades on each side are driven by a lever, symmetrical to the central axis in the cutting direction. The respective lever on each side is in turn driven by a crank, which is arranged on a gear outside the gear axis, and set in a translational oscillating movement perpendicular to the working direction of the lawn mower. Due to the power transmission at the elongated holes of the two cranks and the elongated holes of the four blades, high power loss occurs due to sliding friction. In addition, the levers must be guided in elongated holes, which further increases power loss.While power loss plays a minor role in corded power devices, excessive power loss in battery-operated devices significantly reduces the running time. The object of the invention is therefore to avoid the disadvantages of the prior art and in particular to provide a cutting device that is characterized in that it allows the cutting of an edge area in front of walls or house facades, in particular with a long battery life of approximately 1 hour with a rechargeable battery with an energy of 45 watt hours (Wh). Furthermore, the cutting device should be designed with at least two upper blades in such a way that the at least two upper blades can be driven in a simple manner, preferably in an oscillating manner. In particular, external and additional control devices that synchronize the drive of the at least two upper blades should be avoided.

[0011] According to the invention, this object is achieved by a cutting device according to claim 1.

[0012] Further developments of the invention are the subject of subclaims.

[0013] The cutting device according to claim 1 is characterized in that a common drive unit is provided for driving the plurality of upper blades, preferably for all, but at least for a first and a second upper blade.

[0014] In a first embodiment of the invention, the cutting device comprises a gear box as a common drive unit, preferably with three gears, two of which are essentially the same size, a first and a second gear, each with an eccentric disk, which are driven by a third central gear. The third central gear is driven by a motor pinion. This arrangement of gear and eccentric in one component with direct drive of the upper blades is significantly more effective and friction-free than the prior art, for example US 3973378. In contrast to the invention, in US 3973378 the drive gears with the eccentrics on each side drive a translationally oscillating lever, which causes the upper blades to oscillate rotationally via an elongated hole.This results in significantly more moving components than in the present invention, resulting in much greater friction losses compared to the drive arrangement according to the invention. This leads to short battery life, particularly in battery-operated devices, and is therefore disadvantageous. The device according to the invention is characterized by the fact that, in the particularly friction-free version, it comprises a maximum of three gears: a first and second gear, driven by a central gear. Of course, versions with more than three gears are also conceivable, but this would increase friction losses, which is undesirable.

[0015] Another advantage of the cutting device according to the invention, with only three gears, is its compact design with a very low total weight of less than 2.5 kg (in this case, 2.4 kg without the battery). Furthermore, the device is very handy and easy to operate.

[0016] In a second embodiment of the invention, the cutting device with upper blades arranged on a preferably fixed lower blade comprises a lower blade which has at least one opening for the discharge of cut grass.

[0017] It is particularly preferred if, in an embodiment of a cutting unit with two upper blades and a fixed lower blade, the opening, in particular the one opening, is arranged in the middle of the lower blade, such that this opening is located centrally between the two upper blades.

[0018] In a further developed embodiment, the cutting device comprises a cover in the form of a gear cover, which protects the gear from the ingress of dirt.

[0019] It is particularly preferred if the lower blade, on which at least the first and second upper blades are arranged via a pivot point, is a fixed lower blade. The upper blades fastened to the fixed lower blade perform an oscillating movement around the pivot point. This is achieved by the first and / or second upper blade moving around a first and / or second pivot point in a first and / or second eccentric guide insert with an eccentric disk. It is particularly preferred if the upper blades are moved in a rotationally oscillating manner in the first and / or second eccentric guide insert, preferably with the aid of eccentric disks. In particular, the first and second upper blades rotate in opposite directions, since vibrations resulting from the rotationally oscillating movements can then be reduced or even completely avoided.

[0020] In particular, when using two counter-rotating upper blades compared to one oscillating and one fixed blade, the oscillation amplitude is eliminated and vibrations are thus significantly reduced.

[0021] An advantage of rotary upper blades over translatory blade bars is that they are easier to pre-tension and generate less friction. Furthermore, a clean cut of the blades of grass and / or grass leaves is achieved, for example in ornamental lawns. Preferably, the first upper blade comprises a first drive gear or gearwheel and the second upper blade a second drive gear or gearwheel. In order to implement a joint drive of the first and second upper blades, it is provided that the cutting device comprises a central gearwheel, which preferably acts on the first and second gearwheels of the first and second upper blades. In this way, it is possible to drive both the first upper blade and the second upper blade with a single motor, for example an electric motor, which acts on the central gearwheel.

[0022] The CN 207099687 U features a design with one fixed and two rotating oscillating upper blades. The system of the CN 207099687 U consists of two gears, each with an eccentric gear driven by a pinion on a drive gear shaft. These two parallel gear stages are centrally driven by the motor pinion. In contrast to the invention with three gears and one motor pinion, the CN 207099687 U has six gears and one motor pinion meshing. This design with multiple components increases friction losses, which is particularly disadvantageous for battery-operated devices.

[0023] In contrast, the invention uses a small number of gears. This minimizes friction losses and increases running time. Specifically, the CN 207099687 U has a total of four gear pairs meshing, whereas the invention uses only three. Assuming an efficiency of approximately 0.85 for lubricated plastic gear pairs, the power loss in the CN 207099687 U compared to the invention is at least 15% due to the gear design alone. Minimizing losses is particularly important for battery-powered tools, as this extends running time. The inventive drive design minimizes losses and increases the operating time of batteries used in garden tools.

[0024] US 6314707 also shows a cutting device, particularly for grass cutting, with a fixed lower blade and a cutting blade oscillating on the fixed lower blade. The prior art in the form of US 6314707 has a transversely arranged blade bar with teeth, on which two upper blades oscillate translationally transversely to the cutting direction. These two upper blades are driven by a crankshaft located in the center of the blade bar. The crankshaft is connected to the two upper blades by a connecting rod each. Due to the arrangement of the cranks on the crankshaft, the upper blades move in opposite directions to minimize vibrations. The pretension of the upper blades is achieved via tension wires. Since the upper blades in US 6314707 lie flat on the fixed blade bar, the friction loss is significantly higher than in the arrangement according to the invention.The first and second upper blades are driven in a coordinated manner by the single electric motor; control devices for the drive of the first and second gears are not required. If the eccentric discs in the eccentric insert are aligned oppositely, a common oscillating, counter-directed movement of the first and second upper blades is triggered. This oscillating, counter-directed movement can reduce vibrations. It is preferred if the common gear is driven by the drive unit, in particular the electric motor, whereby the electric motor preferably has a mechanical nominal power in the range of 30 watts to 100 watts. This drive in the aforementioned power range is optimal for cutting blades of grass or grass leaves. When driven by an electric motor of the central drive gear, as described, electric motors with significantly reduced power can be used.A complex bevel gear drive is not required. The significantly smaller motor with the matching power for the cutting device according to the invention has the advantage that the motor, and thus the cutting device, can be manufactured significantly lighter, resulting in weight savings.

[0025] Furthermore, in the event of a jamming of the first and / or second upper blade, for example, the design does not require high motor power to prevent damage to components. This allows the device to be easily assembled and is maneuverable. Weights from 2.0 kg to 3.0 kg, preferably 2.4 kg without the battery for the cutting device, can be achieved.

[0026] One problem with counter-rotating oscillating upper blades is that after just a short period of operation, the cut grass settles between the two upper blades. When the two upper blades move towards each other from an outer cutting position, the respective blades cut the grass leaves and blades of grass on the corresponding cutting side of the lower blade's blade. On the other hand, the two upper blades are limited by the lower blade and a cover to protect the gearbox from dirt and grass penetrating. In addition, a foam seal is provided under a cover in the area of ​​the upper blades to close the design-related air gap between the upper blades and the cover. When the upper blades move towards each other, the clippings are compressed in the gap between the blades.This process occurs with every stroke, and due to the constant pressure exerted by the compressed material, the shielding foam seal cannot prevent the material from penetrating. In a particularly preferred embodiment, an opening is therefore provided to ensure that the material is directed downwards. For this purpose, an opening is preferably arranged in the center of the lower blade such that it is located centrally between the two upper blades and in front of the gearbox seal in the lower blade. The material is then directed downwards through this opening, ensuring that the gearbox remains free of dirt.

[0027] In addition to a mechanical rated power in the range of 30 watts to 200 watts, preferably 40 watts to 100 watts, it is particularly preferred if the drive unit used in the cutting device according to the invention has a power consumption or electrical output of 30 watts to 200 watts. The low power consumption, also due to the low friction losses, means that the cutting device, powered by a storage device, for example a rechargeable battery, has a very long running time of 40 to 80 minutes, preferably 40 to 50 minutes, with a battery with 18 volts, 2.5 ampere hours (Ah), and 45 watt hours of energy.

[0028] It is particularly preferred if the cutting device has a blade arrangement of lower blades and several upper blades, providing a cutting width in the range of 100 mm to 400 mm. This cutting width has the advantage that even strips of lawn left standing when using robotic lawnmowers can be cut with a single cut. A cutting width of 250 mm is particularly preferred. This cutting width ensures that the edge areas of the lawn strips can be safely cut and removed. Furthermore, even small lawns can be mowed with this cutting width. Lawnmowers for small gardens or allotments generally start with a cutting width of at least 220 mm.

[0029] Both the fixed lower knife and the first and second upper knives have narrow knife blades, whereby the elastic knife blades can be easily bent under load and thus impair the cutting result. The disadvantage of the high elasticity of both the upper and lower knives can, however, be advantageous if the upper knives, i.e. the first and second upper knives, are pre-tensioned. By pre-tensioning the upper knife, a better cutting result can be achieved than with a non-pre-tensioned upper knife. Just like with scissors, in this case the knife blades always cut at the contact surface between the upper and lower knives. Due to pre-tensioning, the knives are at a distance from one another which becomes increasingly smaller towards the knife blade. The contact point of the cutting edges of the upper and lower knives is then pre-tensioned. The pre-tension ensures that the cutting edges always remain in contact during operation.If pre-tensioning is insufficient or non-existent, grass, for example, cannot be cut. The grass blades then bend, particularly because the contact surfaces between the upper and lower blades are insufficient. To create pre-tensioning, it is advantageous to provide spacers between the lower blade and the first or second upper blade, which apply or build up the pre-tension.

[0030] By adjusting the pre-tension of the first and second upper knives, the pre-tension applied to the first and second upper knives towards the knife blade becomes increasingly smaller. The elasticity of the blades reduces friction despite the pre-tension and thus the required motor power. The distance between the upper and lower knives, which leads to the pre-tension by the spacer, is 1 to 4 mm, ideally 3 mm. The pre-tension allows the two upper and lower knives to slide very closely against one another. Surprisingly, the pre-tension ensures that the knife blades of the lower knife and the first and second upper knives always lie on top of one another at the cutting surface and are in contact, thus ensuring a clean cut.In order to ensure a sufficient distance between the cutting blades and the grass surface, it is preferably provided that the cutting device comprises at least two wheels, which are preferably arranged along an axis and are adjustable in height.

[0031] To guide the cutting device according to the invention, it is preferably provided that a handle is arranged on the cutting device. This is preferably designed centrally to the cutting device or cutting mechanism and is provided with a handle, a switch, and a holder for a storage device, for example a rechargeable battery. It is very preferred if the handle is not rigidly attached to the cutting device, but with the aid of a joint, preferably a locking joint, in particular a rotatable locking joint. With the aid of the locking joint, it is possible to move the handle into different positions, so that, for example, grass can be cut underneath a bush or tree with the handle in the folded state. Operation with a cordless motor or a battery, for example a lithium-ion battery, is advantageous because this avoids cables.

[0032] It is particularly preferred if the drive unit for driving the first and second outer blades comprises an electric motor. This can be supplied with power using the storage device or an accumulator. The vertical installation makes it possible to drive a central gear without, for example, a bevel gear, which in turn acts on a first and a second gear that is assigned to the first and second outer blades and drives them, in particular, synchronously. Both the central gear and the first and second gears have a diameter and teeth. For drive, it is advantageous if the electric motor acts on the central gear with a motor pinion or pinion, and the motor pinion or pinion, in turn, has teeth. In such a case, it is possible to set a gear ratio by selecting the diameter and number of teeth of the motor pinion or pinion and the central gear.It is particularly preferred if the gear ratio is set at a value of 1:10 based on the number of teeth on the pinion and the first or second gear. The overall gear ratio from the pinion to the eccentric is 1:10, and from the pinion to the central gear is 1:5.9. The specified gear ratio values ​​are merely preferred values ​​that have proven particularly advantageous. Of course, other values ​​are also conceivable for those skilled in the art. For example, the gear ratio from the pinion to the eccentric can range from 1:5 to 1:50.

[0033] With the help of the first and second gears, it is possible to drive the first and second upper blades in such a way that they oscillate against each other.

[0034] Both the lower blade and the first and second upper blades have a plurality of blades. In particular, the lower blade preferably has a central region and a first and second edge region, with the blades of the lower blade being aligned in the central region. The blades of the first and second upper blades can also be extended in the edge regions.

[0035] The extensions of the cutting blades in the middle section of the lower blade ensure that the grass is cut safely when the upper blade moves, as grass blades are guided, which then leads to the grass blades in the rear section being cut off by the blades of the upper blade.

[0036] Particularly preferably, the cutting device can be provided with a separate base plate. The preload of the first and second upper blades is then applied relative to the base plate. Furthermore, the base plate can be provided with at least one skid, which is particularly advantageous for preventing the cutting device from tipping. Tipping of the cutting device would lead to damage to the blades of the first and second upper blades and the lower blade. The skids can preferably be provided symmetrically beneath the base plate.

[0037] The invention will be described in more detail below with reference to the drawings. They show:

[0038] Fig. 1 : a three-dimensional overall view of an inventive

[0039] Cutting device

[0040] Fig. 2: the front part of a cutting device according to the invention

[0041] Fig. 3: a section through the front part of a cutting device according to

[0042] Figure 2

[0043] Fig. 4: a top view of the lower blade with first and second

[0044] upper blade

[0045] Fig. 5: a side view of the upper and lower blades

[0046] Fig. 6: a side view cut away from the front part as shown in Figure 1

[0047] Fig. 7: a cutting device placed on the ground

[0048] Fig. 8: a cutting device mounted on the wall

[0049] Fig. 9: a cutting device inserted under a bush Fig. 10: view of two movable upper blades on a fixed lower blade with at least one opening arranged in the middle of the lower blade

[0050] Fig. 11 : View of two movable upper knives on a fixed lower knife with an opening located in the middle of the lower knife, with the upper knives arranged close to each other

[0051] Figure 1 shows a cutting device 1 according to the invention, which is preferably designed as a lawn edge trimmer. The cutting device 1 comprises a handle 10 with which the device 1 can be pushed by hand. The handle 10 has a handle 20. The handle 20 comprises a switch and, in the illustrated embodiment, a holder for a storage device, in particular a battery. According to the invention, the handle 10 is connected to the cutting device by means of a rotatable joint, in particular a locking joint 30.

[0052] The two upper blades, shown in particular in Figures 2 and 3, as well as the lower blade, are part of the cutting mechanism, designated by reference number 50 in Figure 1. With the aid of the joint 30, it is possible to move the stalk 10 into different positions relative to the cutting mechanism 50. How this can be utilized can be seen, for example, in Figures 7, 8, and 9. The entire cutting device with the cutting mechanism 50 can be guided at a constant distance from the ground by two wheels 40, 41 arranged along an axis.

[0053] Figure 2 shows in detail the area of ​​the cutting unit 50 with the handle 10 attached to the cutting unit 50 via a joint 30. The same components as in Figure 1 have the same reference numerals. This applies in particular to the wheels 40, 41. In addition to Figure 2, the skids 661, 662 on the underside of the base plate 650 (in Figure 6) are shown, which prevent the cutting device from tipping and thus prevent the tips of the blades of the first and second upper blades as well as the lower blade from penetrating the ground. In this way, damage to the blades is avoided. Also shown in Figure 2 is a catching area or diverting area of ​​the housing 550, which serves to collect cut grass. If the device is tilted sideways, the collected grass is removed from the device in such a way that the grass does not accumulate in the area of ​​the upper and lower blades, but is guided away from the cutting device or cutting unit.This prevents the grass blades being cut from bending.

[0054] Figure 3 shows the cutting unit 50 of Figures 1 and 2 in a cutaway view. As can be seen from the cutaway view, the cutting unit comprises a first upper blade 610 (in Figure 4) and a second upper blade 620 (in Figure 4), which are rotatably mounted on a lower blade 600. The lower blade 600 is stationary. Both the first upper blade 610 and the second upper blade 620 are connected to the lower blade 600 via a pivot point 612 for the first upper blade and a pivot point 622 for the second upper blade.

[0055] The eccentric guide inserts 633, 643 with eccentric disks 531, 541 for the first and second upper blades are shown in Figure 4. The first upper blade 610 and the second upper blade 620 are rotationally driven by an electric motor 510, which is installed vertically and acts directly on a central gear 520 with the aid of a motor pinion or pinion 515, without the interposition of, for example, another gear, e.g., a bevel gear. The central gear 520, in turn, is connected to the first gear 530 and the second gear 540, which drive the first upper blade and the second upper blade in rotation via an eccentric insert. The eccentric insert is shown in Figure 4 and is designated by reference numerals 531 and 541. The eccentric discs 531, 541 are arranged oppositely since the driving gears rotate in the same direction.The diameter and number of teeth of the motor pinion 515 and the central gear 520 are coordinated to ensure a gear ratio of 1 to 10 in this case. This means that at an engine speed of 10,000 revolutions per minute under load, a frequency of 2 x 1,000 cuts per minute is achieved, since the blades cut on both flanks of the first and second upper blades. It has been demonstrated that the best cutting results are achieved with this type of arrangement, particularly in tall and dense grass. Eccentric discs 531, 541 (in Figure 4) are arranged below the gears for the rotary eccentric movement with the aid of the first and second gears 530, 540. As can be seen from Figure 3, the drive gears 530, 540 are positioned such that the knives driven thereby, namely the first upper knife 610 and the second upper knife 620, oscillate against each other.With this measure, it is possible to eliminate lateral vibrations generated by the first upper blade 610 and the second upper blade 620 and to minimize resulting vibrations.

[0056] In order to achieve a good cutting result in the middle or the central area with the knife blade of the entire blade width of the lower blade provided by the first and second upper blades, the knife blades 601, 602, 603, 604, 605 in Figure 4 for the lower blade 600 were arranged in alignment in the middle area along the line 90. This means that all knife blades 601, 602, 603, 604, 605 lie on a line 90. In this regard, reference is made to Figure 4. In the front area of ​​the central knife blade 601 of the lower blade 600, no grass is cut by the rotary movement of the first and second upper blades 610, 620 due to the shorter upper blades 614, 624 in this area. However, if the central knife blade 601 of the lower knife is extended, grass blades can be guided and then cut in the rear area of ​​the upper knife blades 614, 624.As previously mentioned, particularly good cutting results are achieved when the first upper blade 610 and the second upper blade 620 are pre-tensioned relative to the base plate forming the lower blade 600. The blades of the upper blades 610, 620 are designated by reference numerals 614, 615, 616, 617, 618, 624, 625, 626, 627, and 628.

[0057] This preload can be seen particularly in the illustration in Figure 5. Figure 4 again shows a top view of the lower blade 600 and the first and second upper blades 610, 620. Clearly visible in Figure 4 are the opposing eccentrics 531, 541 of the first upper blade 610 and the second upper blade 620.

[0058] The sectional side view shown in Figure 5 shows how the preload of the upper blade relative to the base plate is established. By preloading the upper blade 610 relative to the base plate 600 in the rear area of ​​the upper blade, a particularly good cutting result is achieved. To establish the preload, the eccentric guide inserts 633, 643 each have two spacers 635, 645, which generate the preload relative to the pivot point 612 so that the knife blades of the upper blade and lower blade are in contact with each other in every operating position. Each of the eccentric guide inserts has two spacers 635, 645.

[0059] Figure 6 is a side view of the open cutting unit. The same components as in the previous figures bear the same reference numerals. Clearly visible is the upright electric motor 510 with pinion 515, which acts on the central gear 520. The central gear 520 then jointly drives the gear for the first upper blade and the gear for the second upper blade. Also clearly visible are the skids 661, 662, which keep the blade at a distance from the ground.

[0060] Figure 7 shows a first possible way of storing a cutting device according to the invention. For this purpose, the handle 10 is rotated upwards around the pivot point 30, so that the cutting device according to the invention can be placed on the runners 661, 662, for example, in a garage. Alternatively, it is possible, as shown in Figure 8, to hang the device on a wall by rotating the handle 10 around the pivot point 30.

[0061] Figure 9 shows how, by rotating the handle 10 around the pivot point 30, it is possible to guide the cutting device even underneath bushes, for example, in places that are difficult to access, and thus to cut the grass underneath.

[0062] Figures 10 and 11 show in detail a particularly preferred embodiment of the cutting mechanism of the invention with two upper blades 610, 620 which, as shown in Figures 3 and 4, are rotatably mounted on a lower blade 600, wherein the lower blade comprises at least one opening 670 formed in the lower blade 600 for removing cut grass.

[0063] In general, with a cutting unit with counter-rotating oscillating upper blades 610, 620, cut grass settles between the upper blades 610 and 620 after just a short period of operation. Figure 10 shows the two upper blades 610 and 620 in the outer cutting position. When the two upper blades move toward each other, the respective blades 614 and 624 cut the grass leaves and blades of grass on the corresponding cutting side of the blade 601 of the lower blade 600. The cutting blades 601 and 620 are limited to the underside by the lower blade 600. Above, the upper blades are limited by a cover 550 to protect the gearbox from penetrating dirt and grass. In addition, a foam seal (not designated) is provided under the cover 550 in the area of ​​the upper blades 610, 620 in order to close the design-related air gap between the upper blades 610, 620 and the cover 550.

[0064] When the upper blades 610, 620 move towards each other, as shown in Figure 11, the clippings are pressed together in the gap between the knife blades 614 and 624 and pushed in the direction of arrow A, as shown in Figure 11. This process occurs with each lifting movement, and due to the constant pressing of the pressed clippings, the shielding foam seal cannot prevent the clippings from penetrating. According to the invention, in a special embodiment, an opening 670 is provided in the lower blade 600, which ensures that the clippings are diverted downwards. In the embodiment shown, only a single opening 670 is provided, which is arranged in the middle of the lower blade 610 such that this opening 670 is centrally located between the two upper blades and in front of the gear seal in the lower blade. The clippings are then diverted downwards through this opening 670, and the gear remains free of dirt.

[0065] Of course, it would be possible to provide multiple openings instead of a single opening 670 without deviating from the invention. However, the central placement between the two upper blades 610, 620 is important for good grass removal. The described embodiment with opening 670 is a special design of the cutting mechanism of the invention shown in Figures 3 and 4, with two upper blades 610, 620 and a fixed lower blade 600.

[0066] The invention provides, for the first time, a device that achieves excellent cutting results and provides a synchronous drive for multiple upper blades. In particular, edge areas with a width of 100 to 300 mm, especially 200 mm, can be cleanly cut in one direction in a single operation. Furthermore, a special embodiment of the invention is provided that allows for easy removal of cut material without clogging the cutting mechanism.

[0067] The invention includes aspects disclosed in subsequent sentences which form part of the description but are not claims according to J 15 / 55 of the Boards of Appeal

[0068] 1. Cutting device (1), in particular a grass cutting device, preferably a lawn edge cutting device, with at least one cutting device having a blade arrangement comprising at least one lower blade (600) and at least one upper blade (610, 620), which are movable relative to one another, preferably in an oscillating manner, wherein the at least one upper blade has at least a first upper blade (610) and a second upper blade (620), characterized in that the cutting device has a drive unit, preferably in the form of an electric motor (510), for the first upper blade (610) and the second upper blade (620), and the drive unit is a common drive unit for at least the first upper blade (610) and the second upper blade (620).

[0069] 2. Cutting device according to sentence 1, characterized in that the lower blade (600) is a fixed lower blade.

[0070] 3. Cutting device according to one of the preceding sentences 1 to 2, characterized in that the first (610) and / or the second (620) upper blade are connected to the lower blade (600) via a first and second pivot point (612, 622).

[0071] 4. Cutting device according to sentence 3, characterized in that the first upper blade (610) and the second upper blade (620) comprise a first eccentric guide insert (633) and a second eccentric guide insert (643).

[0072] 5. Cutting device according to one of the sentences 1 to 3, characterized in that the first upper blade (610) has a first gear (530) and / or the second upper blade (620) has a second gear (540).

[0073] 6. Cutting device according to one of sentences 1 to 5, characterized in that the cutting device comprises a central gear (520) for driving the first gear (530) and the second gear (540).

[0074] 7. Cutting device according to one of the sentences 1 to 6, characterized in that the drive unit is connected to the central gear (520) for the common drive of the first and second upper blades (610, 620).

[0075] 8. Cutting device according to one of sentences 1 to 7, characterized in that the drive unit comprises an electric motor (510), preferably with a mechanical nominal power in the range of 30 watts to 100 watts.

[0076] 9. Cutting device according to one of the sentences 1 to 8, characterized in that the electric motor (510) has an electrical power of 40 watts to 200 watts.

[0077] 10. Cutting device according to one of the sentences 1 to 9, characterized in that the cutting width of the knife arrangement is in the range 100 mm to 500 mm.

[0078] 11 . Cutting device according to one of the sentences 1 to 10, characterized in that spacers (635) are provided between the first and second upper blades (610, 620) and the lower blade (600), such that a pre-tension of the first and second upper blades is built up.

[0079] 12. Cutting device according to one of the sets 1 to 11, characterized in that the distance between the upper and lower blades adjusted with the aid of the spacers (635) is in the range 1 to 4 mm, preferably 3 mm, for building up a pre-tension.

[0080] 13. Cutting device according to one of the sentences 1 to 12, characterized in that the cutting device has at least two axially arranged impellers (40, 50).

[0081] 14. Cutting device according to one of the sentences 1 to 13, characterized in that the cutting device comprises at least one handle (10) for guidance.

[0082] 15. Cutting device according to one of sentences 1 to 14, characterized in that the handle (10) is preferably arranged centrally on the cutting device and / or the cutting mechanism (50).

[0083] 16. Cutting device according to one of sentences 1 to 15, characterized in that the handle (10) is connected to the cutting device by a joint (30), preferably a locking joint, in particular a rotatable locking joint.

[0084] 17. Cutting device according to one of sentences 1 to 16, characterized in that the drive unit comprises at least one electric motor (510).

[0085] 18. Cutting device according to one of the sentences 1 to 17, characterized in that the electric motor (510) is arranged vertically.

[0086] 19. Cutting device according to one of sentences 1 to 18, characterized in that the electric motor comprises a pinion (515).

[0087] 20. Cutting device according to one of the sentences 1 to 19, characterized in that the pinion (515) drives the central gear (520) which is connected to a first (530) and a second gear (540).

[0088] 21 . Cutting device according to one of the sentences 1 to 20, characterized in that both the pinion (515) and the central gear (520) each have a diameter and teeth.

[0089] 22. Cutting device according to one of the sentences 1 to 21, characterized in that

[0090] The diameter and number of teeth of the pinion (515) and the central gear (520) are matched to one another in such a way that a gear ratio of between 1 to 5 and 1 to 50, preferably 1 to 10, is achieved. 23. Cutting device according to one of the sets 1 to 22, characterized in that the first and second gears (530, 540) are positioned in such a way that the first and second outer blades (610, 620) driven by the first and second gears (530, 540) oscillate against one another.

[0091] 24. Cutting device according to one of the sentences 1 to 23, characterized in that the lower knife has a plurality of knife blades.

[0092] 25. Cutting device according to one of the sentences 1 to 24, characterized in that the lower blade (600) comprises a central region (90) and a first and a second edge region.'

[0093] 26. Cutting device according to one of the sentences 1 to 25, characterized in that the knife blades (601, 602, 603, 604, 605) of the lower knife are aligned in the central region.

[0094] 27. Cutting device according to one of the sentences 1 to 26, characterized in that the knife blades (614, 615, 616, 617, 618, 624, 625, 626, 627, 628) of the upper knives are shortened.

[0095] 28. Cutting device according to one of the sentences 1 to 27, characterized in that the cutting device comprises a base plate (600).

[0096] 29. Cutting device according to one of sentences 1 to 28, characterized in that the first and second upper blades (610; 620) comprise a front and a rear region, and the spacers (635) are arranged such that the first and second upper blades (610, 620) are pretensioned relative to the lower blades (600) in the rear region. Cutting device according to one of sentences 1 to 29, characterized in that at least one skid (660, 662), in particular a sliding skid, is arranged beneath the base plate (600).

Claims

Claims Cutting device (1), in particular grass cutting device, preferably lawn edge cutting device, comprising at least one cutting device, a blade arrangement comprising at least one lower blade (600) and at least one upper blade (610, 620), which are movable relative to each other, preferably oscillating, wherein the at least one upper blade comprises at least one first upper blade (610) and a second upper blade (620), characterized in that the cutting device has a drive unit, preferably in the form of an electric motor (510), for the first upper blade (610) and the second upper blade (620), and the drive unit is a common drive unit for at least the first upper blade (610) and the second upper blade (620), and the drive unit comprises at least three gears, wherein the three gears are two gears of essentially the same size, in particular with essentially the same diameter,The cutting device comprises a first gear (530) and a second gear (540), each with an eccentric disc (531, 541), and a third, central gear is formed to engage with the first gear (530) and the second gear (540), the central, third gear (520) being connected to a pinion (515) of the electric motor. The cutting device according to claim 1 is characterized in that the lower blade (600) is a stationary lower blade. The cutting device according to claim 1 is characterized in that the lower blade has at least one opening (670), preferably in the area between the first and second upper blades (610, 620). Particularly preferably in the middle between the first and second upper blades (610, 620). Cutting device according to any one of the preceding claims 1 to 3, characterized in that the first (610) and / or the second (620) upper blades are connected to the lower blade (600) via a first and second pivot point (612, 622). Cutting device according to claim 4, characterized in that the first upper blade (610) and the second upper blade (620) comprise a first eccentric guide insert (633) and a second eccentric guide insert (643). Cutting device according to any one of claims 1 to 5, characterized in that the drive unit comprises an electric motor (510), preferably with a mechanical rated power in the range of 30 watts to 100 watts, and / or consumes an electrical power of 40 watts to 200 watts.Cutting device according to any one of claims 1 to 6, characterized in that spacers (635, 645) are provided between the first and second upper blades (610, 620) and the lower blade (600) such that a preload is built up on the first and second upper blades (610, 620). Cutting device according to any one of claims 1 to 7, characterized in that the cutting device comprises at least one guide handle (10) and / or. the style (10) is connected to the cutting device by a joint (30), preferably a locking joint, in particular a rotatable locking joint.

9. Cutting device according to one of claims 1 to 8, characterized in that the drive unit comprises at least one electric motor (510), which is preferably arranged vertically and in particular comprises a pinion (515).

10. Cutting device according to one of claims 1 to 9, characterized in that the first and the second upper blade comprise a front and a rear area and spacers (635, 645) are arranged such that the first and the second upper blade is pre-tensioned relative to the lower blade in the rear area.

11. Cutting device according to one of claims 1 to 10, characterized in that spacers (635) are provided between the first and second upper blade (610, 620) and the lower blade (600) such that a preload is built up on the first and second upper blade and in particular the distance between the upper and lower blade set with the aid of the spacers (635) is in the range of 1 to 4 mm, preferably 3 mm, to build up a preload.

12. Cutting device according to one of claims 1 to 11, characterized in that the electric motor comprises a pinion (515), wherein both the pinion (515) and the central gear (520) each have a diameter and teeth and / or The diameter and number of teeth of the pinion (515) and eccentric discs (531, 541) are matched to each other in such a way that a gear ratio of 1 : 10 and / or by pinion (515) and central gear (520) of 1:5.

9. Cutting device according to one of claims 1 to 10, characterized in that the lower blade (600) comprises a central region as well as a first and a second edge region. Cutting device according to one of claims 1 to 13, characterized in that the blades (601, 602, 603, 604, 605) of the lower blade are aligned in the central region and / or the blades (614, 615, 616, 617, 618, 624, 625, 626, 627, 628) of the upper blades are shortened. Cutting device according to one of claims 1 to 14, characterized in that the first and the second upper blade (610, 620) comprise a front and a rear area and the spacers (635) are arranged such that the first and the second upper blade (610, 620) are biased relative to the lower blade (600) in the rear area.Cutting device according to one of claims 1 to 13, characterized in that the cutting device has a storage device, in particular an electrical storage device, in particular an accumulator, preferably an accumulator with a runtime of 20 to 200 minutes, in particular 40 to 80 minutes, in particular 40 to 50 minutes with 18 volts. 2.5 ampere-hours (Ah) and 45 watt-hours of energy and / or the cutting device has a weight of 2.0 kg to 3.0 kg, preferably 2.4 kg, without a storage device, in particular a battery. Cutting device (1), in particular grass cutting device, preferably lawn edge cutting device, comprising at least one cutting device, a blade arrangement comprising at least one lower blade (600) and at least one upper blade (610, 620), which are movable relative to each other, preferably oscillating, wherein the at least one upper blade comprises at least one first upper blade (610) and a second upper blade (620), characterized in that the cutting device has a drive unit, preferably in the form of an electric motor (510), for the first upper blade (610) and the second upper blade (620), and the drive unit is a common drive unit for at least the first upper blade (610) and the second upper blade (620), and the lower blade comprises at least one opening.Cutting device according to claim 17, characterized in that the opening is a single opening (670) arranged substantially centrally between the first upper blade (610) and the second upper blade (620). Cutting device according to any one of claims 17 to 18, characterized in that the cutting device comprises a cover (550) above the first and second upper blades (610, 620). Cutting device according to any one of claims 17 to 19, characterized in that the cutting device comprises a seal, preferably a foam seal. Cutting device according to claim 20. characterized in that the seal is arranged such that it lies under the cover and closes an air gap between the first and second upper blades (610, 620) and the cover (550). Cutting device according to any one of claims 17 to 21, characterized in that the lower blade (600) is a stationary lower blade. Cutting device according to any one of the preceding claims 17 to 22, characterized in that the first (610) and / or the second (620) upper blades are connected to the lower blade (600) via a first and second pivot point (612, 622). Cutting device according to any one of claims 17 to 23, characterized in that the first upper blade (610) and the second upper blade (620) comprise a first eccentric guide insert (633) and a second eccentric guide insert (643).Cutting device according to any one of claims 17 to 24, characterized in that the drive unit comprises an electric motor (510), preferably with a mechanical rated power in the range of 30 watts to 100 watts, and / or consumes an electrical power of 40 watts to 200 watts. Cutting device according to any one of claims 17 to 25, characterized in that spacers (635, 645) are provided between the first and second upper blades (610, 620) and the lower blade (600), such that… that a preload is built up on the first and second upper blades (610, 620). Cutting device according to one of claims 17 to 26, characterized in that the cutting device comprises at least one guide shaft (10) and / or the shaft (10) is connected to the cutting device by a joint (30), preferably a locking joint, in particular a rotatable locking joint. Cutting device according to one of claims 17 to 27, characterized in that the drive unit comprises at least one electric motor (510), which is preferably arranged vertically and in particular comprises a pinion (515). Cutting device according to one of claims 17 to 28, characterized in that the first and the second upper blades comprise a front and a rear region and spacers (635, 645) are arranged such that the first and the second upper blades are preloaded relative to the lower blade in the rear region.Cutting device according to one of claims 17 to 29, characterized in that spacers (635) are provided between the first and second upper blade (610, 620) and the lower blade (600) such that a preload of the first and second upper blade is built up and in particular the distance between the upper and lower blade set with the aid of the spacers (635) is in the range of 1 to 4 mm, preferably 3 mm, to build up a preload.

31. Cutting device according to one of claims 17 to 30, characterized in that the electric motor comprises a pinion (515), wherein both the pinion (515) and the central gear (520) each have a diameter and teeth and / or The diameter and number of teeth of the pinion (515) and eccentric discs (531, 541) are matched to achieve a ratio of 1:10 and / or of pinion (515) and central gear of 1:5.

9.

32. Cutting device according to one of claims 17 to 31, characterized in that the lower blade (600) comprises a central area as well as a first and a second edge area.

33. Cutting device according to one of claims 17 to 32, characterized in that the knife blades (601 , 602, 603, 604, 605) of the lower knife are aligned in the middle area and / or the knife blades (614, 615, 616, 617, 618, 624, 625, 626, 627, 628) of the upper knife are shortened.

34. Cutting device according to one of claims 17 to 33, characterized in that the first and the second upper blade (610; 620) comprise a front and a rear area and the spacers (635) are arranged such that the first and the second upper blade (610, 620) are biased relative to the lower blade (600) in the rear area.

35. Cutting device according to one of claims 17 to 34, characterized in that the cutting device includes a storage device, in particular an electrical storage device, in particular a battery, preferably a battery with a runtime of 20 to 200 minutes, in particular 40 to 80 minutes, in particular 40 to 50 minutes with 18 volts, 2.5 ampere-hours (Ah) and 45 watt-hours of energy and / or the cutting device has a weight of 2.0 kg to 3.0 kg, preferably 2.4 kg, without a storage device, in particular a battery.

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