CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Patent Application

No. 62/971,805, filed on February 7, 2020, the disclosure of which is incorporated herein by reference in its entirety as part of the present application.

Field of Invention:

[0002] The present invention relates to a robotic lawn mower having non-traditional cutters or blades. More particularly, it relates to a lawn mower having at least one set of cutting tools or cutters which is semi-rigid and semi-flexible and may be generally in a form of a single rod or twisted cable or wires, that is normally not considered as a blade with sharp edges for traditional lawn mowers.

Background of Invention:

[0003] Generally, a lawn mower is defined as a machine having rotatable blades which are adjustable for height with respect to the ground, and the machine is capable of moving around on the ground (or over lawns) so that the rotatable blades may cut the grass with smooth appearance and uniform height, when being driven manually, or by combustion engine, as well as by electric power or batteries, etc. Therefore, the basic or essential elements of a lawn mower are: (1) at least a rotatable blade being adjustably mounted on a vehicle or movable carrying platform; (2) driving mechanism for moving the vehicle and the blade; and (3) power source for powering the moving vehicle and/or the rotation of the blades; wherein the vehicle or movable carrying platform may include a chassis or a baseboard and/or a housing to hold everything or every parts together.

[0004] The current trends of lawn mowers are robotic, that is controllable and/or automatically movable; but in any event, the key concerns of lawn mowers are the efficacy of cutting the grass over various types of lawns having various conditions, such as, the sizes, shapes, boundaries, concaves/uneven grounds or levels of grounds, as well as dryness or wetness of grass, etc. Hence, many improvements of lawn mowers have been made with respect to how those elements can work together more efficiently. Now, the focus of improvements may be not only on robotic operation, but also artificial intelligent, aka AI, operation.

Summary of Invention:

[0005] According to the present invention, a lawn mower comprises a chassis for carrying thereon at least a set of rotatable cutting tools which is mounted in the front section of the chassis, said cutting tools being in a form of semi rigid and semi flexible rod or twisted cable or wires; at least two wheels mounted on the sides of the chassis; and driving mechanism for moving the lawn mower around; and rotation mechanism for rotating the cutting tools. The lawn mower includes at least a power source for powering up the driving mechanism and rotation mechanism, which may be preferably a bank of rechargeable batteries, and a control unit for controlling the rotation of the cutting tools at desired speeds or in a_range of adjustable desired speeds as being adopted and suitable for cutting or mowing grass of the lawns in various conditions as well as the adjustment of the height of the cutting tools with respect to the grass of the lawns, wherein the height of the cutting tools is adjustable according to predetermined patterns of lawns where the mower moves around, and is adjustable in response to any random conditions of the lawn.

[0006] Alternatively, the driving mechanism for driving the mower may be powered by the same power source or by a separate power source from the power source of the rotation mechanism for rotating the cutting tools; and a separate control unit is provided for controlling the movement of the wheels in any or all directions in accordance with the predetermined pattens of the lawn, without necessity of turning the front section of the chassis of the mower.

[0007] According to the present invention, the cutting tools may be in the form of a single rod or a twisted cable or wires, and the set of cutting tools or cutting assembly is connected to the shaft of the rotation mechanism for rotating the cutting tools. The rotation mechanism for rotating the cutting tools may be an electric motor that is operable as powered by the power source, i.e., batteries or rechargeable batteries, etc.

[0008] Further according to the present invention, the cutting tools may be in the form of a cross, and the center of the cross of the cutting tools is connected to the shaft of the rotation mechanism for rotating the cutting tools, i.e., to the electric motor.

[0009] Still further, the cutting tools may be alternatively a plurality of uniformly spaced apart rods or twisted cable or wires, which may be three, five, six, eight or more rods or twisted cable or wires uniformly arranged around the rotating shaft, such as, be mounted on a disc connected to the rotating shaft. Moreover, of all the arrangement of robs or cable or wires of the cutting tools, each of the rods may be of a cross section of triangle, or an irregular cross-section which may be of desired flexibility and rigidity. Certainly, the cutting tools could be a blade with sharp edge.

[0010] According to the present invention, there are preferably four wheels mounted on the sides of the chassis, i.e., two at each side. Each of the wheels is independently operated and driven by an electronic motor of the driving mechanism under the control of the control unit for controlling the movement of the wheels. Each of the wheels is connected to the chassis through a suspension that acts in response to the various conditions of the ground or the lawns under the control of the control unit for controlling the movement of the wheels, such as the adjustment of power output, speeds, and direction according to the predetermined patterns of the lawn, or in response to certain random or instant condition of the lawn.

[0011] Details of the present invention may be understood and will be discussed hereinafter in connection with the accompanying drawings. Brief description of the drawings:

[0012] Figure 1a illustrates a perspective view of the lawn mower or robotic lawn mower of the basic embodiment of the present invention.

[0013] Figures 1b and 1c show, respectively, the front view and top view of the lawn mower or robotic lawn mower of the present invention.

[0014] Figure 2a illustrates the main components of the lawn mower or robotic lawn mower of the present invention.

[0015] Figures 2b and 2c show, respectively, the mounting of the main components of the lawn mower or robotic lawn mower of the present invention from various views.

[0016] Figures 3a illustrates the mounting of a sample of cutting tools or a cutting assembly in accordance with the present invention.

[0017] Figure 3b to 3e illustrate, respectively, alternative samples of the cutting tools according to the present invention.

[0018] Figure 4a illustrates the mounting of a moving wheel according to the present invention;

[0019] Figures 4b and 4c illustrate, respectively, the details of the driving motor assembly and suspension for the moving wheels of the present invention.

[0020] Figures 4d to 4g are respectively illustrative of the movement of the moving wheels of the robotic lawn mower according to the present invention, in forward and backward, as well as left and right directions. [0021] Figures 4h, 4j, 4k, and 4m, are respectively illustrative of the movement of the mowing wheels of the robotic lawn mower of the present invention in diagonal directions.

[0022] Figures 4n and 4p are illustrative of the left and right turnings of the mowing wheels of the robotic lawn mower of the present invention.

[0023] Figure 5 illustrates the block diagram of the control unit or units of the robotic lawn mower of the present invention for providing control modes of the operations of motors of the cutting tools and moving wheels.

[0024] Figure 6 illustrates the flow chart of the operation or control of the robotic lawn mower of the present invention.

[0025] Figure 7 shows the arrangement of a sensing and/or detecting System of the present invention, showing possible mountings of the components of the system.

[0026] Figures 8a, 8b and 8c show an alternative embodiment of moving wheels of the present invention.

[0027] Figure 9 illustrates an alternative arrangement of rechargeable batteries as the power source of the present invention.

Detailed description of the Invention:

[0028] Generally, the robotic lawn mower 10 of the present invention as shown in Figures 1a to 1c comprises a housing 11 for holding the main components of the lawn mower 10 therein, a moving assembly 12 usually having four moving wheels 13 as an example, and a cutting or mowing assembly 14 having one or more sets of cutting tools or cutters 15 (as seen in Figures 2a to 2c). Other components are at least one power source 16 including rechargeable battery or batteries 17, and operation control board or boards or units 18 (as seen in Figures 2a to 2c). In addition, there are provided with suspension mechanism 19 (seen in Fig. 2b) for the moving wheels adopted to respond and act to various conditions of the lawn or ground, as well as other necessary mounting structural elements or members. Moreover, a sensing and/or detecting system 20 are provided around the housing or provided at least in the front and rear sections of the mower for detecting the conditions of the grass and ground of the lawn being mowed during the operation of the lawn mower, as described in details in connection with Figure 7.

[0029] Figure 1a is a perspective view of the lawn mower of the basic embodiment of the present invention. The housing 11 is illustrative only, and it may be designed to any shapes as long as being suitable to hold the components of the lawn mower and being of any kinds or styles of industrial designs. Preferably, it may include two compartments 1 la and lib in the one housing 11, one of which 11a is for the cutting tools 15 and the other compartment l ib is for other main components, such as, the power source 16, control unit or units 18. The two compartments 11a and l ib may also be separable, and the compartment 11a for the cutting tools 15 is provided in the front section of the mower and is movable up and down with respect to the other compartment lib, thereby allowing the vertical height adjustment of the cutting tools 15 with respect to the ground or lawn. A chassis or baseboard 9 is a carrying platform for mounting the components and serves as or fits to the bottom of the housing 11, and the chassis 9 is designed in consideration of structural stability, strength and/or durability to support and hold those components thereon. The housing 11 has an upper portion 8 that is formed of any suitable and durable materials and at least offers protection to the components held therein.

[0030] Figures 1b and 1c show, respectively, the front view and top view of the lawn mower of the present invention. Figure 1b shows two sets of cutting tools 15 or two cutting assembly 14 that are mounted in the compartment 11a in the front section of the chassis 9 of the lawn mower, as defined in the forward moving direction; and the moving wheels 13 are connected to the chassis or baseboard 9 of the housing 11 through suitable mounting structure or suspension mechanism 19, along the sides of the other compartment lib of the housing 11 as viewed in the forward moving direction. As seen in Figure 1c, some additional features may include the operation buttons 7, antenna 6, WiFi 5 or Bluetooth 4, and any other available wireless connections or communication devices 3, as well as a viewing or transparent window for a surveillance or monitoring camera 2, that are illustrative and optional because they may also be provided at any part of the housing 11. [0031] Figure 2a illustrates generally the possible arrangement of those main components of the lawn mower according to the basic embodiment of the present invention. There may be one set or two separate sets of rechargeable batteries 17, one or part of which is for operating the cutting assembly 14, or rather provides power to the motor or motors 21 of the cutting tools 15, and the other of which is for providing power to the motors 31 of the moving wheels 13 of the moving assembly 12. However, there may be just one set or bank of rechargeable batteries for powering both of the cutting assembly 14 and the driving or moving assembly 12. The motor or each of the motors 21 of the cutting assembly 14 will rotate or turn the cutting tools 15 at a desired speed or in a range of desired speeds under the control of the control board or unit 18 in order to cut or mow the grass in response to the control signals according to predetermined patterns of a lawn or any feedbacks of the grass and ground conditions from the sensing or detecting system 20. An operation control board or unit 18 is shown in Figure 2a, but there may be two or more control boards or units, etc., depending on the necessary functions for the various operations of the lawn mower. That is to say the control unit 18 could be just one part or component which is designed to control the performance of all the functions, or could be two or more parts or components that control the performance of respective functions of the cutting or mowing assemblyl4 and moving assembly 12.

[0032] Figures 2b and 2c show, respectively, how those components of the lawn mower 10 are mounted on the chassis or baseboard 9 of the robotic lawn mower of the present invention. Again, the arrangement or compartments of the components on the chassis or baseboard 9 are exemplary of possible options. The connections thereof are electrically through wiring or connection circuit board or boards, that are subject for other suitable designs.

[0033] Figures 3a illustrates the mounting of an example of cutting tools 15 or cutting assembly 14 in accordance with the present invention. Two sets of cutting tools 15 are shown in Figure 3a, and the respective motor assemblies 21a and 21b or the motor assembly box # are mounted through each of the two respective openings of the chassis as seen in Figure 2b. The cutting tools 15 include a support disc 15a that is connected centrally or co-axially to the shaft 22 of the motor 21 as in the motor assembly 21a or 21b, and as shown, the cutting tools 15 are in the form of eight twisted cables or wires uniformly allocated around the support disc 15a. Each of the twisted cables or wires 15 is made of semi rigid and semi flexible material, such as stainless steel, or any material that is generally durable and strong enough to sustain the impact of the grass or the like at relatively high rotating speed of the cutting tools 15, thereby cutting the grass. As compared with traditional blade of lawn mowers, the cutting tools or cutters 15 of the present invention do not have very sharp edges, but still can cut the grass efficiently. Nonetheless, any traditional blade with sharp edge may also be an optional or exchangeable set of cutting tools, especially for large areas of lawns, such as football fields or golf courses. Moreover, other alternatives of the twisted cables or wires of the cutting tools may be short rods of stainless steel or similar materials that are durable and strong enough to sustain the impacts of the grass when turning at relatively high speed or speeds. Each of the rods may be of a cross section of square, triangle or even rectangular, or twisted thereof. Again, there is no need to have very sharp edges as traditional blades of lawn mowers are.

[0034] The semi rigid and semi flexible materials also have advantages of directly contacting solid or hard substances, such as walls, fences, and etc., without breaking them. This will benefit and increase significantly the mowing efficiency. Traditional type of blades with sharp edges of lawn mowers will normally leave certain areas of grass uncuttable, that is, between the mower and the hard substances, and may need a timer to do a complete mowing job.

[0035] Figure 3b to 3e illustrate, respectively, alternative examples of the cutting tools 15 of the present invention. As seen, the cutting tools 15 may be as simple as a single or two cables or rods, as well as three, four, five, six, or even more that are usually uniformly allocated round the periphery of the support disc 15a which is usually round in shape. However, it can be understood that a support disc 15a may be in any other forms so long as it may support the rods or twisted cables or wires or the like uniformly such that they can rotate with respect to the center of the disc 15a as co-axial with the shaft 22 of the motor 21.

[0036] Figure 4a illustrates the more details of the mounting of one of the moving wheels 13 of the moving assembly 12 of the present invention. The moving wheel 13 is connected to or mounted on the chassis 9 of the housing 11 of the lawn mower 10 through a motor assembly 31a and suspension mechanism 19. The motor assembly 31a is illustrated in the box wherein a driving motor 31 is accommodated and the motor has a shaft 32 connecting co- axially with the wheel 13 at one end thereof, and the motor 31 is connected electrically through wiring to the control board or unit 18 and the rechargeable battery (not shown). In response to any of conditions of the grass or ground, the motor 31 will drive the wheel 13 in a desired direction under the control of the control unit 18 which generates control signals to operate the motor 31. The operation of the control unit 18 will be discussed hereinafter.

[0037] Figures 4b and 4c illustrate further the motor assembly 31a of driving motor 31 for the moving wheel 13 of the present invention. Inside the motor assembly or accommodating box 31a, the driving motor 31 and its associated accessories are installed, and has various connecting wiring to be connected electrically to the control unit 18 (not shown Figures 4b and 4c); and on the accommodating box of the motor 31a, a support piece 33 extends (as seen in Figures 4a to 4c), protruding away from the box, which serves as a basic piece for connecting with the chassis directly or through a suspension mechanism 19. It can be understood that the motor assembly 21a for the cutting tools 15 may be similar with the motor assembly 31a of the moving wheels 13, and thus, the description of the motor assembly 21a of the cutting tools 15 is omitted. However, other possible form or arrangement of motor assembly 31a may be adopted so long as they are operated independently and cooperatively.

[0038] Regardless of any possible arrangement of the motor assembly 31a for the moving wheels 13, an important feature of the present invention is the capability of those moving wheels 13 to move the lawn mower 10 in any or all directions with or without turning the front section or head of the lawn mower 10, and the wheels may be Mecanum wheels adopted in this basic embodiment of the present invention as shown in Figure 4a or Omni wheels shown in Figures 8a to 8c. The details of the movement of the moving wheels 13 under the control will be described hereinafter.

[0039] The desired capability of the moving wheels may be seen or illustrated in Figures 4d to 4g for the movement of the moving wheels 13 of the lawn mower 10 in any or either of directions of forward and/or backward as well as left and/or right. The adoption of such Mecanum wheels may fulfill the requirements of the aforesaid movement. It is also easy to understand that the movement of the lawn mower in forward and/or backward directions will require all of the four wheels 13 or 13a to 13d to move or to be driven to move in the same direction as shown in Figures 4d and 4e. The cutting assembly 14 or the cutting tools 15 may keep on rotating to cut the grass while the mower 10 moves over the grass on the ground. The movement of the lawn mower 10 in the left direction will require, respectively, that the two wheels 13a, 13c on the left side move or rotate toward each other, while the two wheels 13b, 13d on the right side move or rotate away from each other as the arrows indicate. Likewise, the movement of the lawn mower 10 in the right direction will require, respectively, that the two wheels 13b, 13d on the right side move or rotate toward each other, while the two wheels 13a, 13c on the left side move or rotate away from each other, as the arrows indicate in Figures 4f and 4g.

[0040] Figures 4h and 4j illustrate, respectively, the movement of the robotic lawn mower 10 in a direction somewhat diagonally backwards, as the narrows indicate. If the movement of the lawn mower 10 is somewhat leftwards and backwards, the two of the four wheels, i.e., the left front wheel 13a and the right rear wheel 13d that are diagonally positioned on each side, move or rotate backwards in the same direction, while the other two wheels 13b, 13c being diagonally positioned do not rotate as seen in Figure 4h. If the movement of the lawn mower 10 is somewhat rightwards and backwards, the two of the four wheels, i.e., the right front wheel 13b and the left rear wheel 13c that are diagonally positioned on each side, move or rotate backwards in the same direction, while the other two wheels 13a, 13d being diagonally positioned do not rotate as seen in Figure 4j. Moreover, different driving powers may be applied to the two rotating wheels so that the robotic lawn mower 10 will move in any desired diagonal directions backwards. All of the movements of the lawn mower 10 will be under the control of the control unit 18.

[0041] Similarly, Figures 4k and 4m illustrate, respectively, the desired movement of the lawn mower 10 in the somewhat diagonally forward directions. That is, if the lawn mower is desired to move somewhat leftwards and forwards, the two of the four wheels, i.e., the left rear wheel 13c and the right front wheel 13b that are diagonally positioned on each side, move or rotate forwards in the same direction, while the other two wheels 13a, 13d being diagonally positioned do not rotate as seen in Figure 4k; and if the lawn mower 10 needs to move somewhat rightwards and forwards, the two of the four wheels, i.e., the right rear wheel 13d and the left front wheel 13a that are diagonally positioned on each side, move or rotate forwards in the same direction, while the other two wheels 13b, 13c being diagonally positioned do not rotate as seen in Figure 4m. Again, different driving powers may apply to the two wheels so that the lawn mower will move in any desired diagonal directions.

[0042] As described above, it is possible for the lawn mower 10 of the present invention keeps on cutting the grass, while moving around in any desired directions without turning the head or front of the lawn mower. Sometimes, it is still desired to turn the head or front of the lawn mower 10 so that the cutting tools 15 mounted in the front section of the mower 10 may cut the grass at the edges of the lawn. As seen in Figures 4n, the right turning can be performed by having the two wheels 13b, 13d on the right side to move or rotate backward, while the two wheels 13a, 13c on the left side to move or rotate forward as the arrows indicate. Similarly, the left turning can be performed by having the two wheels 13a, 13c on the left side to move or rotate backward, while the two wheels 13b, 13d on the right side to move or rotate forward as the arrows indicate. Then, it can be understood that the lawn mower of the present invention may mow or cut the grass over the entire piece of lawn even close to the edges of the lawn without need to use a trimer.

[0043] Figure 5 illustrates the block diagram of the control unit or units 18 of the robotic lawn mower of the present invention. The control unit 18 is the operation system of the lawn mower 10, and the control unit 18 or operation system comprises at least CPU, RAM, ROM for storing and processing operational programs and signals with respect to various operational modes of the motors that need to operate, respectively, the cutting tools and moving wheels. The basic and/or predetermined operational modes are pre-installed as operational programs, and will be selected to operate the motors when the specific piece of lawn is determined with the received or retrieved lawn profile data of this piece of lawn. The control unit 18 also comprises various communications means, such as, Wi-Fi, Bluetooth, and 4G/5G modules, that establish wireless communication and/or telecommunication with remote database or control center (not shown) and transmit control demand signals to and receive lawn profile data from the remote database and control center to determine proper operation and to adjust operation modes with respect to this specific piece of lawn. That is to say that the sensors or cameras are provided in connection with the control unit so as to provide real time of grass conditions, and to adjust retrieved operation mode or modes in response thereto. Then, the CPU will issue and send the operational signals to the respective motors for the cutting tools and/or moving wheels.

[0044] Figure 6 illustrates the flow chart of the operation or control of the robotic lawn mower of the present invention. Before a robotic lawn mower starts a mowing job, the control unit or the operation system of the lawn mower will first verify numbers of things, as illustrated in Figure 6, which include if it is the right or correct lawn to be mowed, the right date, authorized user, and the conditions of the mower, and so on. After everything is checked out and verified correctly, the robotic lawn mower starts working in accordance with the specific lawn profile data and desired or predetermined operation mode or modes of the lawn mower. The lawn profile data describes the particular piece of lawn in great details. The operation mode or modes will be retrieved and sent to the CPU to start operations of the motors under the control. That is the robotic lawn mower is ready to perform the mowing job for all zones of the particular lawn. The robotic lawn mower will first Use the data to generate a mowing plan for the zones of the lawn to be mowed and check whether the power source is enough for mowing the particular lawn. If everything is checked OK, the robotic lawn mower starts the mowing job as guided and controlled by the mowing plan. If any unexpected obstacle is detected or found, the robotic lawn mower will initiate the obstacle avoidance procedure in response to and to handle the situation. Once the obstacle is overcome, the lawn mower will then continue on to finish the job of the particular zone or zones of the lawn as the predetermined operation mode or the scheduled mowing plan indicates. It will repeat this routine for each of remaining zones until all zones are completed, i.e., finishing the mowing jobs.

[0045] Figure 7 shows schematically the arrangement of a sensing and/or detecting system 20 of the present invention, showing the mountings of the respective parts of the sensing and detecting system 20. It includes at least a basic subsystem 45 and AI system 46 that are parts of the operation system 40 of the control unit 18, a front binocular camera 41, a laser ranging radar 42, a back or rear camera 43, and a pair of ultrasonic ranging sensors 44, as well as a surveillance camera 47 and anti-drop sensors 48 each of which is near each of the moving wheels 13. The laser ranging radar 42, the front binocular camera 41, the back camera 43, the ultrasonic ranging sensors 44, the surveillance camera 47 and the anti-drop sensors 48 start working once the lawn mower 10 starts working as guided and initiated by the mowing plan after verification and checking out the various conditions as stated above. All of the laser ranging radar 42, the front binocular camera 41, the back camera 43, the ultrasonic ranging sensors 44, and the anti-drop sensors 48, as well as the surveillance camera 47 will send to the AI subsystem 46 of the operation system 40 the real time or actual conditions of the grass of the lawn when the lawn mower 10 continues the mowing jobs over a particular piece of lawn; and the AI subsystem 46 generates a signal representing the actual condition or an obstacle, if so detected, to the basic subsystem 45, indicative of any adjustment operation or avoidance of any obstacles; and then the basic subsystem 45 will send adjustment signals to the respective motors 21, 31 of the cutting tools 15 and/or moving wheels 13. Afterwards, the lawn mower 10 will continue the wowing jobs based on the remaining mowing plan to finish the jobs. A power source will be needed for all of the parts of the sensing and detecting system 20, and it may be a separate power source or it may be the same power source or sources for the operation of the cutting tools 15 and/or moving wheels 13.

[0046] Figures 8a, 8b and 8c show, respectively, different views of an alternative embodiment of moving wheels of the present invention, i.e., Omni wheels. They just show the details of such wheels, including uniformly allocated rotatable blocks along each side of each of the wheels, i.e., each wheel having two parallel side sections. Figure 8a shows the inner side of the wheel, i.e., facing the housing, and Figure 8b shows the outer side of the wheel. Figure 8c shows the side view of the wheel. Each of the rotatable blocks may rotate based on bearings mounted and connected on each of the parallel side sections of the wheel, and as seen in Figure 8c, the rotatable blocks are received and mounted in recesses of the side section of the wheel. Therefore, the rotatable blocks may move somewhat horizontally or perpendicularly with respect to the rotation of the wheel. That is the rotatable blocks will rotate, as so desired and controlled, to accomplish the movements as described above and illustrated in Figures 4d to 4g, Figures 4h and 4j, Figures 4k and 4m, as well as Figures 4n and 4p. Accordingly, the lawn mower may move in all directions or turning as controlled by the control unit and/or guided by the mowing plan as so chosen or retried for the operational data.

[0047] Figure 9 illustrates an alternative arrangement of rechargeable batteries or the power source as well as the control board, as the main components of the lawn mower of the present invention. It comprises two sets of batteries or two power sources, instead of one set of batteries or power source as in Figures 2a to 2c. As compared with the arrangement of the main components in Figures 2a to 2c, it just indicates that the arrangement of all components of the lawn mower should be balanced and convenient in consideration of particular designs of the components or parts or desired arrangement thereof to be suitable of or fit any desired profile of lawn mowers, as well as how many rechargeable batteries or power sources required which is designed in consideration of capacity of the lawn mower. In any event, power sources or rechargeable batteries are the most weighted and occupied more space in the robotic lawn mowers.