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EP-4736625-A2 - SKID PLATE

EP4736625A2EP 4736625 A2EP4736625 A2EP 4736625A2EP-4736625-A2

Abstract

A skid plate for a robotic lawnmower, comprises an approximately circular plate with a central opening (13), for a hub (6b), and means of attachment (14, 15). The skid plate (2b) is attachable to the robotic lawnmower. An edge portion (7) of the circular plate is bent to extend transversally to a main plane (8) of the circular plate. An outer peripheral edge (11) thereof extends in a single plane. A robotic lawn mower comprises an electric motor connected to a rotatable cutting head (1b). The cutting head is connected to a cutting disk (3b) with at least one knife (4b) at its periphery. A skid plate (2b) as above is arranged below the cutting disk (3b).

Inventors

  • ELONSSON, MARTIN
  • OLSEN, Ronny
  • LARSSON, SVANTE
  • AHLIN, PETER
  • PETERSSON, MARKUS

Assignees

  • Husqvarna AB

Dates

Publication Date
20260506
Application Date
20230118

Claims (13)

  1. Skid plate (2b) for a lawn mower, comprising an approximately circular plate with means of attachment (15), whereby the skid plate (2b) is attachable to the lawn mower, and a central portion (10) of the skid plate (2b) extends in a plane at a distance from a main plane (8) of the circular plate, wherein the means of attachment (15) are arranged in the central portion (10), and an edge portion (7) of the circular plate is bent to extend transversally to said main plane (8) of the circular plate, and an outer peripheral edge (11) thereof extends in a single plane.
  2. Skid plate (2b) according to claim 1, wherein the single plane of the peripheral edge (11) is arranged at substantially the same level as the plane of the central portion (10).
  3. Skid plate (2b) according to claim 1 or claim 2, wherein a cross section of the edge portion (7) has, at least partly, the shape of a circle segment.
  4. Skid plate (2b) according to claim 3, wherein the circle segment has a radius of 1 to 30 mm.
  5. Skid plate (2b) according to claim 3 or 4, wherein the radius of the circle segment is greater than a thickness of the skid plate (2b).
  6. Skid plate (2b) according to any of the preceding claims, wherein the distance between the plane of the central portion (10) and the main plane (8) of the circular plate is between 1 and 30 mm.
  7. Skid plate (2b) according to any of the preceding claims, wherein openings (15) for fastening elements (14) are arranged in the central portion (10).
  8. Skid plate (2b) according to any of the preceding claims, wherein the skid plate (2b) is manufactured from steel.
  9. Robotic lawn mower comprising an electric motor connected to a rotatable cutting head (1a, 1b), which is connected to a cutting disk (3b) with at least one knife (4b) at its periphery, and a skid plate (2b) according to any of the preceding claims, arranged below the cutting disk (3b).
  10. Robotic lawn mower according to claim 9, wherein the knives (4b) of the cutting disk (3b) are arranged to extend above and partly radially outside of the skid plate (2b).
  11. Robotic lawn mower according to claim 9 or claim 10, wherein attachment means (5b) for attachment of the knives (4b) to the cutting disk (3b) extend below the level of the outer peripheral edge (11) of the skid plate (2b).
  12. Robotic lawn mower according to any of claims 9 to 11, comprising a hub (6b) of the cutting head (1b) and a main plane (8) of the skid plate (2b) is arranged below the hub (6b).
  13. Robotic lawn mower according to any of claims 9 to 12, wherein the knives (4b) are pivotably arranged on the cutting disk (3b).

Description

Field of the invention The present disclosure relates to a skid plate for a robotic lawnmower, comprising an approximately circular plate with a central opening, for a hub, and means of attachment, whereby the skid plate is attachable to said robotic lawnmower. The disclosure also relates to a robotic lawn mower comprising an electric motor connected to a rotatable cutting head, which is connected to a cutting disk with at least one knife at its periphery. Background In areas with high demands on the lawn quality, such as fairways on golf courses, there is a demand for lawn mowers which are able to cut grass at a low cutting height. At the same time, the mowers must avoid scalping the lawn, i. e. cutting into the lawn at an excessively low height or even into the ground. The problem of scalping is particularly pronounced in areas where the ground is uneven and may result in areas where the grass turns brown or is completely removed. EP3571917B1 discloses a lawn mower which is designed to protect objects left on the ground from the mowing knives. The mower is provided with a bottom disk, below a rotatable cutting disk. The bottom disk has a plurality of prong portions, which extend beyond the knives on the cutting disk. The prong portions are fairly wide, extending over approximately half of the circumference of the bottom disk, and hence over half of the area which would otherwise be reachable by the knives, had the bottom disk not been mounted on the lawn mower. The bottom disk may serve well as a guard protecting objects that are accidentally encountered on the ground. At the same time, the risk of scalping is limited. However, the result of the mowing is impaired, and in areas with high demands on the quality of the mowing, the result is not satisfactory. In areas where the cutting height is set to be low, such as fairways on golf courses, this problem is particularly pronounced. An additional problem with the construction of EP3751917B1 is that the cutting height as such may not be adequate for applications where a low cutting height with a quality is required, since the knives are a considerable distance from the ground, even at their lowest height. Hence there is a need for a lawn mower which provides a high quality mowing at a low cutting height without scalping the lawn in areas with uneven ground conditions. Summary It is an object of the present disclosure to solve, or at least mitigate, parts or all of the above-mentioned problems. To this end, there is provided a skid plate as initially outlined, wherein an edge portion of the circular plate is bent to extend transversally to a main plane of the circular plate, and an outer peripheral edge thereof extends in a single plane. Hereby a skid plate with an approximate outer shape of a shallow bowl is attained. The skid plate, when arranged at the bottom of the cutting head of a lawn mower, would not present any sharp edges that could accidentally cut into the ground and cause scalping of the lawn. The outer edge of the skid plate is directed transversally to the main plane thereof, which means that it would be directed away from the ground in a mounted position on a lawnmower. In an embodiment of the skid plate, a cross section of the edge portion thereof has, at least partly, the shape of a circle segment. Hereby the portion of the skid plate that would most likely come into contact with the ground when it is mounted on a lawn mower may be gentle to the lawn, and scalping may be avoided. In an embodiment of the skid plate, the circle segment has a radius of 1 to 30 mm. Hereby the total height of the skid plate is limited, which may be an advantage in applications where a very low cutting height may be desired. In particularly preferable embodiments, the radius is in the interval of 5 to 15 mm, and even more preferably it is approximately 10 mm. In a further embodiment, the radius of the circle segment is greater than a thickness of the skid plate. Hereby sharp bends that may scalp, cut or otherwise damage the lawn are eliminated. In further embodiments a central portion of the circular plate extends in a plane at a distance from a main plane of the circular plate. Hereby an offset middle portion of the skid plate is attained. Such an offset portion may be useful as a socket for a hub of the cutting head, for fastening elements etc., that would otherwise extend beyond the skid plate in its transversal direction. In further embodiments the plane of the central portion is arranged at substantially the same level with the outer peripheral edge. Hereby the height/depth of above-mentioned socket may be maximized without increasing the total outer dimensions of the skid plate. This is advantageous when a low cutting height is desired. In even further embodiments, the distance between the plane of the central portion and the main plane of the circular plate is between 1 and 30 mm. As mentioned, a low height of the plate is desirable, for attaining as low a