Blade guard for a robot lawnmower

• US 10,244,678 B2
• Filed: 10/25/2017
• Issued: 04/02/2019
• Est. Priority Date: 08/25/2016
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Lydon, Peter J., Doughty, Brian W.
• Primary Examiner(s): Torres, Alicia
• Application Number:
  US15/793,261
• Publication Number:
  US 20180054963A1
• Time in Patent Office: 524 Days
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: A01D 34/66 with two or more cutters
• CPC Class Codes: A01D 34/81 Casings; Housings A01D34/71 takes precedence
• CPC Class Codes: A01D 34/828 Safety devices

Abstract

An autonomous robot lawnmower includes a chassis, a drive supporting the chassis above a lawn and configured to maneuver the robot lawnmower about the lawn, and a motorized lawn cutting assembly including one or more blades. The robot lawnmower further includes a first blade guard movably mounted to a first lateral side of the chassis and extending from the chassis toward the lawn, and a second blade guard movably mounted to a second lateral side of the chassis and extending from the chassis toward the lawn.

Claims

1. An autonomous robot lawnmower comprising:

a drive supporting the robot lawnmower above a lawn and configured to maneuver the robot lawnmower about the lawn;

a motorized lawn cutting assembly comprising one or more blades;

a first blade guard movably mounted to a first lateral side of the robot lawnmower, positioned at least partially below a horizontal plane in which the one or more blades of the cutting assembly are located, and extending from the first lateral side of the robot lawnmower toward the lawn, the first blade guard being movable toward the one or more blades of the cutting assembly, wherein the first blade guard has a substantially planar front facing surface forming a non-perpendicular angle with a substantially planar outward facing surface of the first blade guard such that a rearward directed force on the front facing surface moves the first blade guard towards the one or more blades of the cutting assembly; and

a second blade guard movably mounted to a second lateral side of the robot lawnmower and extending from the second lateral side toward the lawn, the second blade guard being movable toward the one or more blades of the cutting assembly, wherein the second blade guard has a front facing surface forming a non-perpendicular angle with an outward facing surface of the second blade guard such that a rearward directed force on the front facing surface of the second blade guard moves the second blade guard towards the one or more blades of the cutting assembly.

2. The robot lawnmower of claim 1, wherein the front facing surface of the first blade guard forms a non-perpendicular angle with a lower edge of the first blade guard such that the first blade guard translates upward in response to contact between the front facing surface of the first blade guard and an object on the lawn as the robot lawnmower moves in a forward direction across the lawn.

3. The robot lawnmower of claim 2, wherein the non-perpendicular angle between the front facing surface of the first blade guard and the lower edge of the first blade guard is between 100 and 170 degrees.

4. The robot lawnmower of claim 1, wherein the first blade guard is movable toward the one or more blades to position a portion of the first blade guard between a portion of the one or more blades of the cutting assembly and the lawn when an inwardly directed force is applied to the first blade guard.

5. The robot lawnmower of claim 4, wherein the portion of the first blade guard positioned between the portion of the one or more blades and the lawn when the inwardly directed force is applied to the first blade guard is positioned below a cutting circumference, the cutting circumference being defined by rotation of an outer tip of the one or more blades.

6. The robot lawnmower of claim 1, wherein the first blade guard comprises a spring rotatably mounting the first blade guard to the first lateral side of the robot lawnmower.

7. The robot lawnmower of claim 1, wherein the first blade guard comprises a spring translatably mounting the first blade guard to the first lateral side of the robot lawnmower.

8. The robot lawnmower of claim 1, wherein the first blade guard is movable away from the one or more blades of the cutting assembly when an outwardly directed force is applied to the first blade guard.

9. The robot lawnmower of claim 1, further comprising a bumper, the first blade guard being movably mounted to the bumper.

10. The robot lawnmower of claim 1, wherein the outward facing surface of the first blade guard includes a recessed portion and a raised portion surrounding the recessed portion.

11. The robot lawnmower of claim 1, wherein a cutting area is defined by operation of the one or more blades, the cutting area having a width between 75% and 95% of a distance between the first lateral side and the second lateral side of the robot lawnmower.

12. The robot lawnmower of claim 1, wherein the first blade guard is rotatable outward away from the one or more blades.

13. The robot lawnmower of claim 1, wherein:

the outward facing surface of the first blade guard comprises an outward side facing portion, and

the front facing surface of the first blade guard comprises a front facing portion and one or more front facing angled portions, the one or more front facing angled portions extending rearwardly and laterally from an outer edge of the front facing portion to the outward side facing surface of the first blade guard.

14. The robot lawnmower of claim 1, wherein an angle between an angled portion of the front facing surface of the first blade guard and the outward facing surface of the first blade guard is greater than 90 degrees.

15. An autonomous robot lawnmower comprising:

a drive supporting the robot lawnmower above a lawn and configured to maneuver the robot lawnmower about the lawn;

a motorized lawn cutting assembly comprising one or more blades; and

a blade guard movably mounted to a lateral side of the robot lawnmower, positioned at least partially below a horizontal plane in which the one or more blades of the cutting assembly are located, and extending from the lateral side of the robot lawnmower toward the lawn, the blade guard being movable toward the one or more blades of the cutting assembly;

wherein the blade guard has a rear facing surface forming a non-perpendicular angle with an outward facing surface of the blade guard such that a forward directed force on the rear facing surface moves the blade guard towards the one or more blades of the cutting assembly.

16. The robot lawnmower of claim 15, wherein the rear facing surface of the blade guard forms a non-perpendicular angle with a lower edge of the blade guard such that the blade guard translates upward in response to contact between the rear facing surface and an object on the lawn as the robot lawnmower moves in a rearward direction across the lawn.

17. The robot lawnmower of claim 16, wherein the non-perpendicular angle between the rear facing surface of the blade guard and the lower edge of the blade guard is between 100 and 170 degrees.

18. The robot lawnmower of claim 15, wherein the blade guard is movable toward the one or more blades to position a portion of the blade guard between a portion of the one or more blades of the cutting assembly and the lawn when an inwardly directed force is applied to the blade guard.

19. The robot lawnmower of claim 15, wherein:

the blade guard is a first blade guard,

the lateral side is a first lateral side, and

the robot lawnmower further comprises

a second blade guard movably mounted to a second lateral side of the robot lawnmower and extending from the second lateral side toward the lawn, the second blade guard being movable toward the one or more blades of the cutting assembly,

wherein the second blade guard has a rear facing surface forming a non-perpendicular angle with an outward facing surface of the second blade guard such that a forward directed force on the rear facing surface of the second blade guard moves the second blade guard towards the one or more blades of the cutting assembly.

20. The robot lawnmower of claim 15, wherein the blade guard comprises a spring rotatably mounting the blade guard to the lateral side of the robot lawnmower.

21. The robot lawnmower of claim 15, wherein the blade guard comprises a spring translatably mounting the blade guard to the lateral side of the robot lawnmower.

22. The robot lawnmower of claim 15, wherein:

the outward facing surface comprises an outward side facing portion, and

the rear facing surface comprises a rearward facing portion and one or more rearward facing angled portions, the one or more rearward facing angled portions extending forwardly and laterally from an outer edge of the rearward facing portion to the outward facing side surface of the blade guard.

23. The robot lawnmower of claim 15, wherein an angle between an angled portion of the rear facing surface and the outward facing surface is greater than 90 degrees.

24. The robot lawnmower of claim 15, wherein the rear facing surface is substantially planar, and the outward facing surface is substantially planar.

25. An autonomous robot lawnmower comprising:

a drive supporting the robot lawnmower above a lawn and configured to maneuver the robot lawnmower about the lawn;

a motorized lawn cutting assembly comprising one or more blades; and

a blade guard movably mounted to a lateral side of the robot lawnmower and extending from the lateral side of the robot lawnmower toward the lawn, the blade guard being movable toward the one or more blades of the cutting assembly;

wherein the blade guard has a front facing surface angled away from an outward facing surface of the blade guard such that a rearward directed force on the front facing surface moves the blade guard towards the one or more blades of the cutting assembly; and

wherein the blade guard is movable toward the one or more blades such that an inwardly directed force applied to the blade guard positions a portion of the blade guard between a portion of the one or more blades of the cutting assembly and the lawn and below a cutting circumference defined by a rotation of an outer tip of the one or more blades.

26. The robot lawnmower of claim 25, wherein the front facing surface of the blade guard angled away from a lower edge of the blade guard such that the blade guard translates upward in response to contact between the front facing surface and an object on the lawn as the robot lawnmower moves in a forward direction across the lawn.

27. The robot lawnmower of claim 26, wherein an angle between the front facing surface of the blade guard and the lower edge of the blade guard is between 100 and 170 degrees.

28. The robot lawnmower of claim 25, wherein:

the blade guard is a first blade guard,

the lateral side is a first lateral side, and

the robot lawnmower further comprises

a second blade guard movably mounted to a second lateral side of the robot lawnmower and extending from the second lateral side toward the lawn, the second blade guard being movable toward the one or more blades of the cutting assembly,

wherein the second blade guard has a front facing surface being angled away from an outward facing surface of the second blade guard such that a rearward directed force on the front facing surface of the second blade guard moves the second blade guard towards the one or more blades of the cutting assembly.

29. The robot lawnmower of claim 25, wherein the blade guard comprises a spring rotatably mounting the blade guard to the lateral side of the robot lawnmower.

30. The robot lawnmower of claim 25, wherein the blade guard comprises a spring translatably mounting the blade guard to the lateral side of the robot lawnmower.

31. The robot lawnmower of claim 25, wherein the blade guard is movable away from the one or more blades of the cutting assembly when an outwardly directed force is applied to the blade guard.

32. The robot lawnmower of claim 25, further comprising a bumper, the blade guard being movably mounted to the bumper.