Non-slip plate and robotic lawnmower
By designing the curved edges and offset center structure of the anti-slip plate, the problem of lawn stripping at low cutting heights was solved, achieving high-quality lawn cutting and device compactness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUSQVARNA AB
- Filing Date
- 2023-03-20
- Publication Date
- 2026-06-09
AI Technical Summary
Existing lawnmowers tend to strip the grass at low cutting heights, especially on uneven ground, and existing protective structures affect mowing quality.
Design a skid plate with curved edges and an offset center. The outer edge of the skid plate extends laterally to avoid sharp edges, and the center is offset to accommodate fastening elements, ensuring that the cutting head and blade rotate close to the ground.
It effectively avoids the risk of lawn stripping, achieves high-quality low-cut results, and maintains the compact structure of the cutting device.
Smart Images
Figure CN116982465B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a skid plate for a robotic lawnmower, the skid plate comprising: a nearly circular plate having a central opening for a hub; and an attachment means thereby the skid plate can be attached to the robotic lawnmower.
[0002] This disclosure also relates to a robotic lawnmower comprising an electric motor connected to a rotatable cutting head, the cutting head being connected to a cutting disc having at least one blade at its periphery. Background Technology
[0003] In areas where high lawn quality is required (such as fairways on golf courses), lawnmowers capable of cutting at lower heights are needed. At the same time, the lawnmower must avoid scalping the grass, i.e., cutting too low into the grass or even into the ground. Scalping is particularly problematic in uneven areas and can cause the grass in that area to turn brown or be completely cleared.
[0004] EP 3571917 B1 discloses a lawnmower designed to protect objects left on the ground from the impact of the mowing blades. The lawnmower has a base plate located below a rotatable cutting disc. The base plate has multiple forked portions that extend beyond the blades on the cutting disc.
[0005] The forked section is quite wide, extending over about half of the perimeter of the bottom plate, so that when the bottom plate is not mounted on a lawnmower, it extends over half of the area that the blades can reach.
[0006] The bottom plate effectively protects against objects accidentally encountered on the ground and prevents the risk of stripping. However, it can affect mowing results, and in areas where high-quality mowing is required, the results are unsatisfactory. This problem is particularly pronounced in areas where the cutting height is set low (such as fairways on golf courses).
[0007] Another problem with the structure of EP 3751917 B1 is that such a cutting height may not be sufficient for applications that require lower cutting height and higher quality, because even at its lowest point, the blade is still quite far from the ground.
[0008] Therefore, there is a need for a lawnmower that can provide high-quality cutting at a lower cutting height without stripping the lawn in areas (even in areas with uneven ground conditions). Summary of the Invention
[0009] The purpose of this disclosure is to solve or at least mitigate some or all of the aforementioned problems. To this end, an anti-slip plate, initially outlined, is provided, wherein the edge portion of the circular plate is curved to extend laterally to the main plane of the circular plate, and the outer peripheral edge of the anti-slip plate extends in a single plane.
[0010] This results in a skid plate with an approximate shallow bowl shape. When positioned at the bottom of the lawnmower's cutting head, this skid plate will not present any sharp edges that could accidentally cut into the ground and cause turf stripping. The outer edge of the skid plate points laterally towards its main plane, meaning that its mounting position on the lawnmower will be away from the ground.
[0011] In an embodiment of the anti-slip plate, the cross-section of the edge portion of the anti-slip plate has at least partially a circular segment shape.
[0012] Therefore, the part of the anti-slip plate that is most likely to come into contact with the ground when installed on a lawnmower may be flat for the lawn and can prevent it from peeling off.
[0013] In the implementation of the anti-slip plate, the radius of the circular segment is 1mm to 30mm.
[0014] Therefore, the total height of the anti-slip plate is limited, which can be an advantage in applications where very low cutting heights may be desired. In a particularly preferred embodiment, the radius is in the range of 5 mm to 15 mm, and more preferably about 10 mm.
[0015] In another embodiment, the radius of the circular segment is greater than the thickness of the anti-slip plate.
[0016] This eliminates sharp bends that could peel, cut, or otherwise damage the lawn.
[0017] In another embodiment, the central portion of the circular plate extends in a plane at a distance from the main plane of the circular plate.
[0018] This results in an offset middle portion of the anti-slip plate. This offset portion can be used as a groove for a hub, fastening element, etc., which would otherwise extend beyond the anti-slip plate in the lateral direction.
[0019] In another embodiment, the central portion is arranged at approximately the same height as the outer perimeter.
[0020] This allows for maximizing the height / depth of the aforementioned groove without increasing the overall external dimensions of the anti-slip plate. This is advantageous when a lower cutting height is desired.
[0021] In another embodiment, the distance between the plane of the central portion and the main plane of the circular plate is between 1 mm and 30 mm.
[0022] As mentioned above, a lower plate height is desirable to achieve the lowest possible cutting height. In a particularly preferred embodiment, the distance is in intervals of 3 mm to 10 mm, and more preferably about 5 mm.
[0023] In some embodiments, the central opening and the opening for fastening elements are arranged in the central portion.
[0024] Thus, the fastening elements and hub of the cutting head are concentrated on a limited portion of the anti-slip plate, thereby making the rest of the anti-slip plate as smooth as possible. In embodiments where the central portion is offset from the main plane of the circular anti-slip plate, no part of the hub or fastening element may extend beyond the main plane of the anti-slip plate when already mounted on the lawnmower. The risk of stripping the lawn through these portions is eliminated, while keeping the external dimensions to a minimum.
[0025] In some implementations, the anti-slip plate is made of steel.
[0026] This allows for the provision of durable anti-slip boards. It minimizes the risk of board deformation and eliminates the risk of a deformed board (which may have sharp edges) accidentally stripping the lawn from an undesirable shape.
[0027] According to the second aspect, a robotic lawnmower solves or at least mitigates some or all of the aforementioned problems, wherein an anti-slip plate according to the present disclosure is arranged below the cutting disc in the robotic lawnmower.
[0028] This resulted in a lawnmower where the risk of stripping the lawn was significantly reduced or eliminated. When the lawnmower moves over the area to be mowed, the lower, rounded edge is most likely the part that primarily contacts the ground.
[0029] In a second aspect of the implementation, the blades of the cutting disc are arranged to extend above the anti-slip plate and partially radially to the outside of the anti-slip plate.
[0030] Therefore, the blade can contact the grass around the outer perimeter of the anti-slip plate, and the cutting result can be of high quality.
[0031] In some implementations, the attachment device for attaching the blade to the cutting disc extends below the height of the outer peripheral edge of the anti-slip plate.
[0032] This allows the anti-slip plate to be installed very close to the cutting disc. The attachment device does not need to be completely contained above the anti-slip plate but can extend downwards, i.e., partially nested within it. Thus, the cutting disc and its blades in the lawnmower can be installed very close to ground height. Only the anti-slip plate separates the ground from the blades, preventing the grass from being stripped away.
[0033] In some implementations, the hub of the cutting head extends through the central opening of the anti-slip plate, and the main plane of the anti-slip plate is arranged below the hub.
[0034] As a result, the external dimensions of the cutting device in the lawnmower can be further reduced. As can be seen axially and radially, the hub of the cutting head can be arranged entirely within the outer limits of the anti-slip plate.
[0035] In some implementations, the blade can be pivotally arranged on the cutting disc.
[0036] This provides another measure to eliminate the risk of lawn stripping. If the blades encounter excessive cutting resistance, they pivot inward. In unlikely cases where the blades contact the ground or the bottom of the lawn, regardless of the disclosed anti-slip plate, they may not move forward with the rotating cutting disc but instead yield and pivot inside the outer periphery of the cutting disc and anti-slip plate. Thus, the lawn is not damaged.
[0037] It should be noted that embodiments of the present invention can be embodied through all possible combinations of the features listed in the claims. Furthermore, it should be understood that each embodiment described for this apparatus can be combined with the method defined according to the second aspect of the present invention, and vice versa. Attached Figure Description
[0038] The above and other objects, features, and advantages of the invention will be better understood by referring to the following illustrative and non-limiting detailed description of preferred embodiments of the invention, wherein the same reference numerals will be used for similar elements, in the accompanying drawings:
[0039] Figure 1a This is a schematic view taken from the side of a cutting head with an anti-slip plate according to the prior art;
[0040] Figure 1b It is based on the anti-slip plate according to this disclosure. Figure 1a A view of the cutting head;
[0041] Figure 2 From the basis Figure 1b A cross-sectional view of the cutting head and anti-slip plate from the side; and
[0042] Figure 3 From Figure 1b and Figure 2 A view taken from below the anti-slip plate and cutting head.
[0043] All these figures are schematic, not necessarily drawn to scale, and generally only show the parts necessary to illustrate these embodiments, where other parts may be omitted. Detailed Implementation
[0044] Figure 1a A cutting head 1a with a slip plate 2a according to the prior art is shown. A cutting disc 3a is arranged above the slip plate 2a and is rotated by the cutting head 1a. A plurality of blades 4a are arranged on the cutting disc 3a near the periphery of the cutting disc. According to any known prior art, the blades 4a can be pivotally or fixedly arranged using an attachment device 5a. A hub 6a of the cutting head 1a extends below the slip plate 2a.
[0045] To complete mowing at a lower height, the cutter head 2a must move along and very close to the ground. If the ground is uneven, it is obvious that the outer edge of the cutter head 2a and the blade 4a may come into contact with the ground from the side, creating a risk of stripping the lawn. In many applications, the cutting head 1a is tilted slightly forward, and the cutting disc 3a and the cutter head 2a are also tilted slightly. This increases the risk of stripping the lawn.
[0046] Figure 1b A cutting head 1b with an anti-slip plate 2b according to this disclosure is shown. Corresponding to prior art cutting heads, the cutting head 1b has a cutting disc 3b mounted thereon. A plurality of blades 4b are mounted on the cutting disc 3b in a manner known in the prior art. In some embodiments, the blades 4b may be fixed, but it would be particularly advantageous if these blades were pivotally mounted so that they yield when encountering an obstacle. An attachment device 5b is present in… Figure 1b Invisible in the middle, but in Figure 2 They can be seen in [the text].
[0047] The anti-slip plate 2b is preferably connected to the cutting head via a bearing device 9, so that the anti-slip plate 2b is not rotated by the motor rotating the cutting disc 3b. The anti-slip plate 2b can slide in contact with the lawn in a translational motion according to the movement of the robotic lawnmower, but the anti-slip plate avoids constant rotation that could be harmful to the lawn.
[0048] The anti-slip plate 2b of the disclosed embodiment includes a circular plate having an extended main plane 8 that coincides with the downward-facing surface of the anti-slip plate 2b.
[0049] The anti-slip plate 2b has an edge portion 7 that extends laterally to the main plane 8 of the circular plate. Therefore, the anti-slip plate 2b of this disclosure has a slightly larger range in the axial direction than the prior art anti-slip plate 2a.
[0050] like Figure 1b and Figure 2As can be seen, the edge portion 7 curves upward to form a bowl-shaped anti-slip plate 2b. The outer peripheral edge 11 is substantially circular and extends continuously in a single plane. Inside the edge portion 7, there is a free space between the height of the outer upper edge of the edge portion 7 and the height of the main plane 8. In this free space, the attachment device 5b of the blade 4b can be accommodated. Since this free space is substantially circular, the attachment device 5b can rotate together with the cutting disc 3b about the central axis of the cutting head 1b.
[0051] During the rotation of the cutting disc 3b, the attachment device 5b moves in a circular motion around the central axis inside the edge portion 7 and below the height of the outer peripheral edge. The attachment devices 5a do not interfere with the grass to be cut, and although they move close to the ground, they are separated from the ground only by the main plane 8 of the anti-slip plate 2b.
[0052] Figure 2 It is also shown that the central portion 10 of the anti-slip plate 2b is offset from the main plane 8. In the illustrated embodiment, the central portion 10 is arranged at substantially the same height as the outer peripheral edge 11 of the anti-slip plate 2b. The resulting groove 12 has an extension in the axial direction similar to that of the edge portion 7. Therefore, the maximum total height of the anti-slip plate 2b in the axial direction is substantially unaffected by the central portion 10.
[0053] The groove 12 has a central opening 13 through which the offset plate passes, and the hub 6 can extend through this central opening in the mounting position of the anti-slip plate 2b. Since the opening 13 is offset from the main plane 8 of the anti-slip plate 2b, the groove 12 can accommodate the hub 6 integrally therein. The hub 6 may not extend outside the groove 12, and the anti-slip plate 2b can be positioned at a minimum distance from the ground during mowing.
[0054] Furthermore, one or more fastening elements 14 for securing the anti-slip plate 2b to the hub 6 are arranged and fully accommodated in the groove 12. The anti-slip plate 2b is provided with one or more openings 15. These fastening elements 14 are in Figure 3 As can also be seen, since neither the hub 6 nor the fastening element 14 extends outside the groove 12, a very low cutting height can be achieved. In some embodiments, other attachment devices besides the fastening element 14 passing through the hole 15 are conceivable. For example, snap-on mounting elements can be used.
[0055] According to this disclosure, in a robotic lawnmower, blades 4b are arranged on a cutting disc 3b to rotate through it. A skid plate 2b is arranged below the blades 4b such that the blades extend through a narrow slot between the cutting disc 3b and the skid plate 2b. Because the skid plate 2b is designed to accommodate an attachment device 5b, the slot between the cutting disc 3b and the skid plate 2b can be minimized, and the blades 4b can rotate very close to the ground.
[0056] In order to allow the disclosed anti-slip plate 2b to be mounted on an existing cutting head and to have all the advantages described above, the axial dimension of the cutting disc 3b can be larger than that of the cutting disc 3a according to the prior art. Figure 1a The axial dimension of the cutting disc 3b is large. The cutting discs 3a and 3b are attached to the lawnmower at the same height, but the larger axial dimension of the disclosed cutting disc 3b positions the blade 4b closer to the ground than prior art blades. In a particularly advantageous embodiment, the blade can be arranged approximately 10 mm closer to the ground than prior art blades. The disclosed anti-slip plate 2b described above fits well into the remaining space between the blade 4b and the ground.
[0057] Because the blades 4b are preferably pivotally arranged, they can yield and rotate more or less back into the periphery of the anti-stripping plate 2b if they encounter an obstacle or excessive obstruction. This feature minimizes the risk of stripping the lawn. The gentle curve of the edge 7 of the anti-stripping plate 2b has the same effect of minimizing the risk of stripping. These two features work independently of each other, but their combination in a robotic lawnmower is certainly particularly advantageous.
[0058] The present invention has been described above with reference to several embodiments. However, it will be readily understood by those skilled in the art that other embodiments besides those disclosed above may also be included within the scope of the present invention as defined by the patent claims.
[0059] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude plural cases.
Claims
1. A skid plate for a robotic lawnmower, the skid plate comprising: An approximately circular plate having a central opening (13) for a hub (6b); and an attachment device thereon, whereby the anti-slip plate (2b) can be attached to the robotic lawnmower, wherein the edge portion (7) of the circular plate is curved to extend laterally to the main plane (8) of the circular plate, and the outer peripheral edge (11) of the anti-slip plate extends in a single plane; characterized in that the central portion of the circular plate extends in a plane at a distance from the main plane (8) of the circular plate; and the plane of the central portion (10) is arranged at substantially the same height as the outer peripheral edge (11).
2. The anti-slip plate (2b) according to claim 1, wherein, The cross section of the edge portion (7) has at least a partially circular shape.
3. The anti-slip plate (2b) according to claim 2, wherein, The radius of the circular segment is from 1 mm to 30 mm.
4. The anti-slip plate (2b) according to claim 2, wherein, The radius of the circular segment is greater than the thickness of the anti-slip plate (2b).
5. The anti-slip plate (2b) according to claim 1, wherein, The distance between the plane of the central portion (10) and the main plane (8) of the circular plate is between 1 mm and 30 mm.
6. The anti-slip plate (2b) according to claim 1, wherein, The central opening (13) and the opening (15) for fastening element (14) are arranged in the central part (10).
7. The anti-slip plate (2b) according to claim 1 or 2, wherein, The anti-slip plate (2b) is made of steel.
8. A robotic lawnmower, comprising: An electric motor is connected to a rotatable cutting head (1a, 1b), the cutting head being connected to a cutting disc (3b), the cutting disc having at least one blade (4b) at its periphery; and an anti-slip plate (2b) according to any one of claims 1 to 7, the anti-slip plate being disposed below the cutting disc (3b).
9. The robotic lawnmower according to claim 8, wherein, The blade (4b) of the cutting disc (3b) is arranged to extend above the anti-slip plate (2b) and partially radially to the outside of the anti-slip plate.
10. The robotic lawnmower according to claim 8 or 9, wherein, The attachment device (5b) for attaching the blade (4b) to the cutting disc (3b) extends below the height of the outer peripheral edge (11) of the anti-slip plate (2b).
11. The robotic lawnmower according to claim 8 or 9, wherein, The hub (6b) of the cutting head (1b) extends through the central opening (13) of the anti-slip plate (2b), and the main plane (8) of the anti-slip plate (2b) is arranged below the hub (6b).
12. The robotic lawnmower according to claim 8 or 9, wherein, The blade (4b) can be pivotally arranged on the cutting disc (3b).