Abstract
The present disclosure relates to a robotic lawnmower fence (1) comprising a bracket (3) with two legs (9′, 9″), which are essentially straight and parallel, and a crossbar (11), which extends between upper ends (9′a, 9″a) of the two legs (9′, 9″) and perpendicular to the legs (9′, 9″). Opposite free ends (9′b, 9″b) of the legs (9′, 9″) are adapted to be anchored in the ground (17) and two support elements (5), each adapted to be arranged along respective leg (9′, 9″) in the extension direction (L) thereof to define a maximum depression depth (D) of the legs (9′, 9″) into the ground (17). The disclosure also relates to a fence system (49) comprising at least two fences (1).
Claims
1. A robotic lawnmower fence comprising; a bracket with two legs, which are essentially straight and parallel, and a crossbar, which extends between upper ends of the two legs and perpendicular to the two legs, wherein opposite free ends of the two legs are adapted to be anchored in the ground; and two support elements, each adapted to be arranged along a respective leg of the two legs in an extension direction of the two legs to define a maximum depression depth of the two legs into the ground.
2. The robotic lawnmower fence according to claim 1, wherein the crossbar is essentially straight.
3. The robotic lawnmower fence according to claim 1, wherein each support element of the two support elements comprises at least one aperture, wherein the free end of the respective leg of the bracket is adapted to be inserted through the aperture and wherein the support element is movable along said extension direction of the respective leg.
4. The robotic lawnmower fence according to claim 3, wherein each leg of the bracket is provided with at least one support element stop arrangement, wherein said support element stop arrangement is adapted to define an upper restriction of a movement of the support element along the respective leg.
5. The robotic lawnmower fence according to claim 4, wherein said support element stop arrangement comprises a bend of the bracket.
6. The robotic lawnmower fence according to claim 3, wherein a length of the support element along the extension direction of the respective legs defines the maximum depression depth of the respective legs into the ground.
7. The robotic lawnmower fence according to claim 1, wherein the crossbar is configured to extend at a height above the ground, when the fence is inserted straight into the ground to the maximum depression depth, of between 70 and 170 mm.
8. The robotic lawnmower fence according to claim 1, wherein the two legs and the two support elements define the maximum depression depth to be between 80 and 250 mm.
9. The robotic lawnmower fence according to claim 1, wherein the bracket is of metal.
10. The robotic lawnmower fence according to claim 9, wherein the bracket is a steel wire with a thickness of between 3 and 9 mm.
11. The robotic lawnmower fence according to claim 9, wherein a surface of the bracket is treated with a powder coating.
12. The robotic lawnmower fence according to claim 1, wherein the free ends of the two legs are chamfered to define end tips.
13. The robotic lawnmower fence according to claim 1, wherein each of the two support elements is made of a plastic.
14. The robotic lawnmower fence according to claim 1, wherein each of the two support elements is made in a single piece.
15. The robotic lawnmower fence according to claim 1, wherein the robotic lawnmower fence is connectable to an adjacent, second robotic lawnmower fence that is identical to the robotic lawnmower fence.
16. The robotic lawnmower fence according to claim 1, wherein each of the two support elements comprises two parallel apertures, allowing connecting the robotic lawn mower fence in series with an adjacent, identical robotic lawnmower fence.
17. A fence system comprising the robotic lawnmower fence and the second robotic lawnmower fence of claim 15.
18. The fence system according to claim 17, wherein the system further comprises a robotic lawnmower.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein:
[0026] FIG. 1A is a schematic view of a bracket according to a first embodiment;
[0027] FIG. 1B is a schematic view of a bracket according to a second embodiment;
[0028] FIG. 2A is a schematic view of a support element according to a first embodiment;
[0029] FIG. 2B is a schematic view of a support element according to a second embodiment;
[0030] FIG. 3A is a schematic illustration of an assembly of a robotic lawnmower fence according to a first embodiment;
[0031] FIG. 3B is a schematic illustration of an assembly of a robotic lawnmower fence according to a second embodiment;
[0032] FIG. 4 is schematic view of a robotic lawnmower system;
[0033] FIG. 5A is a schematic illustration of an installation of a robotic lawnmower fence according to a first embodiment; and
[0034] FIG. 5B is a schematic illustration of an installation of a robotic lawnmower fence according to a second embodiment.
[0035] All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary to elucidate the embodiments, wherein other parts may be omitted.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0036] Each of FIGS. 1A and 1B illustrates a respective bracket 3 according to a first embodiment (FIG. 1A) and a second embodiment (FIG. 1B), respectively. The bracket 3 is made of a material that can withstand various weather conditions without being significantly affected, for example a metal. The bracket 3 has two legs 9′, 9″, which are essentially straight and parallel, and a crossbar 11, which extends between upper ends 9′a, 9″a of the two legs 9′, 9″ and is perpendicular to the legs 9′, 9″. The crossbar 11 is essentially straight. The shape of the bracket 3 can resemble a U that have been turned upside down. The legs 9′, 9″ and the crossbar 11 can be formed as separate parts, which are joined to form the U-shape but are preferably made from a single piece of material that is bent to form the U-shape with two legs 9′, 9″ and a crossbar 11. To create the bracket 3 from a single piece of material, a steel wire may be used. The diameter of the wire must be thin enough to be able to reasonably easy to bend but wide enough to withstand an impact from a robotic lawnmower. A wire diameter of 3 to 9 mm is particularly suitable for meeting these criteria, and a steel wire with a diameter of about 6 mm has been found to be preferred. The surface of the bracket 3 can be treated to withstand various weather conditions better than un untreated surface. The surface of the bracket 3 may be provided with a powder coating in a suitable colour to be perceived as a discrete part of a garden or a lawn installation and protects the bracket 3 from various weather conditions. When the bracket 3 is formed by bending the wire to form a U-shape, two bends 13a, 13b are created. Each bend 13a, 13b is located at a transition between the crossbar 11 and respective upper end 9′a, 9″a of the two legs 9′, 9″. Each leg 9′, 9″ of the bracket 3 can also be provided with further bend 15a, 15b, arranged along the longitudinal extension of each leg 9′, 9″, below the first bend 13a, 13b, as seen in the second embodiment of FIG. 1B.
[0037] Each leg 9′, 9″ of the bracket 3 has a respective free end 9′b, 9″b, which are adapted to be pressed into the ground to a certain depth. To reduce the amount of force that is required to force the free ends 9′b, 9″b into the ground, the free ends 9′b, 9″b may be chamfered to define end tips 19a, 19b. The bevelled angle can, for example, be of at least 45° compared to a straight end edge of the free end.
[0038] Each of FIGS. 2A and 2B illustrates a respective support element 5 according to a first (FIG. 2A) and a second (FIG. 2B) embodiment, respectively. The support element 5 is adapted to be arranged along respective leg 9′, 9″ of the bracket 3 in the extension direction L thereof to define a maximum depression depth of the legs 9′, 9″ into the ground.
[0039] The support element 5 is made of a plastic. If a thermoplastic material is used, for example polypropylene, the support element 5 can be form as a single piece through injection moulding. The support element 5 comprises at least one aperture 25 and the free end 9′b, 9″b of a leg 9′, 9″ is adapted to be insert through this aperture 25. When the support element 5 has been connected to the leg 9′, 9″, it can be moved along the extension direction L of the leg 9′, 9″. The aperture 25 can extend along the entire support element 5 in its longitudinal extension direction. The size of the aperture 25 may big enough for a leg of the bracket to be inserted though the opening but small enough to provide some friction between the leg 9′, 9″ and the support element 5 when the support element 5 is moved along an extension direction of the leg 9′, 9″ between the free ends 9′b, 9″b of the leg 9′, 9″ and the crossbar 11. The aperture 25 may be a through hole.
[0040] The support element 5 can have different shapes. According to the first embodiment, as seen in FIG. 2A, the support element 5 has the shape of a rectangle. The rectangle has two short sides 27a, 27b, two long sides 29a, 29b, a first side face 31 defined by the short and long sides 27a, 27b, 29a, 29b, facing the user when the support element 5 connected to the bracket 3, and a second side face (not shown), also defined by the short and long sides 27a, 27b, 29a, 29b and facing in the opposite direction away from the user, when the support element 5 is connected to the bracket 3. The first side face 31 and the second side face (not shown) are mirror images of each other, which facilitates the injection moulding and makes it possible to reduce the cost for providing a mould used for the injection moulding. The support element 5 is provided with at least two apertures 25a, 25b. Each aperture 25a, 25b extends through the entire support element 5 along a respective long side 29a, 29b in the longitudinal extension direction thereof. Each aperture 25 may be completely enclosed by walls around the perimeter thereof. The apertures 25 may also partly be enclosed by walls along the perimeter thereof as seen in FIG. 2A, to reduce the weight and manufacturing costs of the support element 5. The support element 5 can also be provided with a third aperture 33, which connects the first side face 31 to the second side face (not shown), providing an ergonomic grip when the support element 5 is connected to the bracket 3.
[0041] According to a second embodiment, as seen in FIG. 2B, the support element 5 has the shape of a cone. One aperture 25 is centrally arranged through the entire support element 5 in the longitudinal direction thereof. The cone has an upper side 37a and a lower side 37b.
[0042] FIG. 3A shows the assembly of a fence 1 according to the first embodiment. The free ends 9′b, 9″b of the legs 9′, 9″ of the bracket 3 are each inserted though the aperture 25 of a respective support element 5. When the support elements 5 have been attached to the bracket 3, they can be moved along the legs 9′, 9″ in an extension direction L thereof. The size of the aperture 25 is such that there is a friction between the support elements 5 and respective legs 9′, 9″ so that the support elements 5 do not slip off the legs 9′, 9″ due to gravity. To define an upper restriction of the movement of the support element 5 along the leg 9, the bracket 3 is provided with at least one support element stop arrangement 35. The support element stop arrangement 35 can be an integral part of the bracket 3 or an external part attached to the bracket 3. According to the first embodiment, there are two support element stop arrangements 35, defined by the bends 13a, 13b of the bracket 3 located at the transition between the crossbar 11 and respective upper end 9′a, 9″a of the two legs 9′, 9″. Each support element stop arrangement 35 provides an upper restriction of the movement of the respective support element 5 along the respective leg 9′, 9″. When the support elements 5a, 5b have been moved along the legs 9′, 9″ of the bracket 3 until they reach this upper restriction, the upper short side 27a of the support element 5 will rest against the bend 13 between the crossbar 11 and the leg 9. When the fence 1 is pressed into the ground 17, the length of the support elements 5 will define the height H of the fence above the ground, and thereby also the maximum depression depth D of the legs 9′, 9″ into the ground 17. When the fence 1 has been pressed into the ground 17 to the maximum depression depth D, the lower short side 27b of the support element 5 will rest against the ground 17, while the upper short side 27a of the support element 5 rest against the bend 13 formed at the transition between the crossbar 11 and the leg 9 of the bracket 3.
[0043] FIG. 3B shows the assembly of a fence 1 according to the second embodiment. The free ends 9′b, 9″b of the bracket 3 are each inserted though the aperture 25 of a respective support element 5. When the support elements 5 have been attached to the bracket 3, they can be moved along the legs 9′, 9″ in an extension direction L thereof. The size of the aperture 25 is such that there is a friction between the support elements 5 and respective legs 9′, 9″ so that the support elements 5 do not slip off the legs 9′, 9″ due to gravity. To define an upper restriction of the movement of the support element 5 along the leg 9, the bracket 3 is provided with at least one support element stop arrangement 35. The support element stop arrangement 35 can be an integral part of the bracket 3 or an external part attached to the bracket 3. According to the second embodiment, there are two support element stop arrangements 35, configured as bends 15, creating a sinusoidal shape of each of the legs 9′, 9″ of the bracket 3 that defines an upper restriction of the movement of the support element 5 along each leg 9. This bend 15 is arranged along the extension direction L of each leg 9 at a distance below the respective bend 13a, 13b formed at the transition between the crossbar 11 and each leg 9 of the bracket 3. When the fence 1 is pressed into the ground 17, the length of the support elements 5 will, together with the positions of the support element stop arrangements 35 along the respective legs, define the height H of the fence above the ground 17, as well as the maximum depression depth D of the legs 9′, 9″ into the ground 17. When the fence 1 has been pressed into the ground 17 to the maximum depression depth D, the lower part 37b of the cone will rest against the ground 17, while the upper part 37a of the cone rests against the bend 15.
[0044] The support element can also be designed so that a part of the support element is pushed into the ground and thereby contributes to a steady anchoring if the fence is placed in soft ground.
[0045] FIG. 4 illustrates a robotic lawnmower system. The system comprises a robotic lawnmower 7, a charging station 39 for the robotic lawnmower 7 and a boundary wire 41 for demarcate of a working area W of the robotic lawnmower 7. The robotic lawnmower 7 comprises a chassis 43 and a body part 45. The chassis 43 is supported by the body part 45 through several connection points (not shown). The body part 45 comprises all essentially parts for operation of the robotic lawnmower 7, such as wheels, cutting equipment, motors, battery etc.
[0046] The boundary wire 41 sends a signal that the robotic lawnmower 7 detects when it is close to the boundary wire 41 that makes the robotic lawnmower 7 to turn around not to enter the area outside the boundary wire 41 and keeps the robotic lawnmower 7 within the working area W. Sometimes obstacles may exist within the working area W, such as garden furniture, a trampoline, or bulbous plants, that you want to prevent the robotic lawnmower 7 from running into or might get stuck beneath. A temporary fence makes it possible to block sub-areas S within the existing work area W where the robotic lawnmower 7 not shall operate. This temporary fence can be the physical fence according to the first or second embodiment described above, as illustrated by the fence 1.
[0047] This fence 1 is designed so that the robotic lawnmower 7 collides with the fence 1, which is in the right height from ground 17 (FIGS. 3A, 3B) relative to the free course and the height of the chassis on the robotic lawnmower 1, so that the robotic lawnmower 1 does not get stuck between the ground 17 and the fence 1. Preferably the impact between the fence 1 and the robotic lawnmower 7 takes place between a bumper 47 on the front side of the chassis 43 of the robotic lawnmower 7 and the crossbar 11 of the bracket 3. After the impact, the robotic lawnmower 7 will turn away from the fence 1 and operate another area within the working area W.
[0048] When the fence 1 has been pressed straight into the ground to the maximum depression depth, as seen in FIGS. 3A and 3B, the crossbar 11 will extend at a height H of between 70 and 170 mm above the ground 17. The height H of the crossbar 11 above ground 17 should preferably be high enough that if a robotic lawnmower 7 that hits the crossbar 11 neither gets stuck between the crossbar 11 and the ground 17, nor stuck on top of the crossbar 11, but instead hits the crossbar 11 with the bumper 47 and turns around in another direction. Since the size of the robotic lawnmower 7 and thus the height of the chassis 43 and the position of the bumper 47 may vary, a height of the crossbar 11 above ground of 70 to 170 mm is typically suitable for most situations. According to the first embodiment FIG. 3A, the height H is dependent on the length of the support elements 5. According to the second embodiment, FIG. 3B, the height H depends on the size of the support element 5 and the location of the bend 15 along the extension direction of the leg 9, below the bend 13 at the translation between the crossbar 11 and the leg 9 of the bracket 3.
[0049] The maximum depression depth D, that is defined by the legs 9′, 9″ of the bracket 3 and the support elements 5a, 5b, may typically be between 80 and 250 mm. The legs 9′, 9″ of the bracket 3 should preferably be enough rooted into the ground 17 that when the lawnmower 7 runs into the crossbar 11 of the bracket 3, the fence 1 will not be significantly affected. The support elements 5a, 5b help stabilize the bracket 3 if the fence 1 is placed in soft ground since the lower parts 27b, 37b of the support elements 5a, 5b rest against the ground 17 when the fence 1 has been inserted to maximum depression depth D.
[0050] The support element 5 according to the first embodiment, as shown in FIG. 2A is provided with two parallel apertures 25a, 25b. Each aperture 25 extends through the entire support element 5 along each long side 29 in the longitudinal extension direction thereof. A leg 9′ of a first bracket 3 can be inserted through the first aperture 25a arranged along the first long side 29a of the support element 5 and a leg 9″ of a second bracket 3 can be inserted through the second aperture 25b arranged along the opposite long side 29b of the same support element 5, connecting two identical fences 1 in series. Several fences 1 may be connected to each other creating a fence system 49, as illustrated in FIG. 5A. The fence system 49 may be connected to a closed loop.
[0051] FIG. 5A shows a fence system 49 according to the first embodiment, comprising of sixteen fences 1. Since two fences 1 are connected to each other through the same support element 5, only a small space d is obtained between two adjacent fences 1; this space d is too small for the robotic lawnmower 7 to get stuck in. By providing an interconnected fence system 49, the ability to resist an impact from the robotic lawnmower 7 will be improved compared to a single stand-alone fence. The entire fence system 49 can be removed from the ground, moved to a new location, and inserted to the ground again as a unit. The fence system 49 can be expanded with an infinite number of fences 1. Different shapes of the fence system 49 may be created to delimit a certain area or an obstacle of arbitrary size and shape within the working area of the robotic lawnmower.
[0052] It is also possible to delimit a large area within the working area of the robotic lawnmower with fences 1 according to the second embodiment, as seen in FIG. 5B. Two adjacent fences 1 are not interconnected with each other but are instead independent units that are arranged close to each other. This arrangement of fences has also a small space d between each fence but does not have the same benefits regarding impact resistance as the fence system according to FIG. 5A.
[0053] The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.
[0054] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.
