AU2017100173A4

AU2017100173A4 - Cutting assembly and lawn mower

Info

Publication number: AU2017100173A4
Application number: AU2017100173A
Authority: AU
Inventors: Haishen Xu
Original assignee: Chevron HK Ltd
Current assignee: Chevron HK Ltd
Priority date: 2016-04-18
Filing date: 2017-02-15
Publication date: 2017-03-23
Anticipated expiration: 2025-02-15
Also published as: CN107302864A; CN107302864B; DE202017100938U1

Description

2017100173 15 Feb 2017

CUTTING ASSEMBLY AND LAWN MOWER RELATED APPLICTION INFORMATION

[0001] This application claims the benefit of Chinese Patent Application No. CN 201610240451.1, filed on April 18, 2016, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present disclosure relates generally to a cutting assembly and a lawn mower with the cutting assembly.

BACKGROUND OF THE DISCLOSURE

[0003] Lawn mowers are a kind of gardening tools, which are used to mow lawns. A cutting blade mounted on the lawn mower can be rotated so as to cut grass.

[0004] During the operation of the lawn mower, the grass is expected to be cut into small pieces as soon as possible. Currently known cutting blades of lawn mowers are single strip-shaped metal plates. The cutting edge of the known cutting blade only can cut once. And the grass clippings cut by the cutting blade is long which can’t satisfy the user’s requirements.

[0005] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

SUMMARY

[0006] In one aspect of the disclosure, a cutting assembly includes a first cutting element driven to rotate around a first axis, the first cutting element being formed with a first cutting edge, and a second cutting element rotatably connected with the first cutting element around a second axis, the second cutting element being formed with a second cutting edge. The second axis is arranged at a position different from the first axis. The first cutting edge has a first cutting area and, the second cutting edge has a second cutting area, the first and second cutting areas are at least partially 1 2017100173 15 Feb 2017 overlapped.

[0007] In another aspect of the disclosure, a lawn mower includes a motor, a deck being formed with a cutting chamber and a cutting assembly driven by the motor and accommodated in the cutting chamber. The cutting assembly includes a first cutting element driven to rotate around a first axis, the first cutting element being formed with a first cutting edge, and a second cutting element rotatably connected with the first cutting element around a second axis, the second cutting element being formed with a second cutting edge. The second axis is arranged at a position different from the first axis. The first cutting edge has a first cutting area and, the second cutting edge has a second cutting area, the first and second cutting areas are at least partially overlapped.

[0008] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG 1 is a schematic view of an exemplary cutting assembly.

[0010] FIG 2 a schematic view of the cutting assembly in FIG 1, wherein the cutting assembly is in a working state.

[0011] FIG 3 is a schematic view of cutting area of the cutting assembly in FIG 1.

[0012] FIG 4 is a schematic view showing a distance between a first axis and a second axis of the cutting assembly in FIG 1.

[0013] FIG 5 is a schematic view showing an angle between a first linear segment and a second linear segment of the cutting assembly in FIG 2.

[0014] FIG 6 is a schematic view of a first cutting element and a second cutting element of the cutting assembly in FIG 2 in a height direction.

[0015] FIG 7 is a schematic view of a lawn mower applying the cutting assembly in FIG 1. 2 2017100173 15 Feb 2017 [0016] FIG 8 is an enlarged view of a part of the lawn mower in FIG 7.

[0017] FIG 9 is a schematic view of another embodiment of the cutting assembly.

[0018] FIG 10 a schematic view of the cutting assembly in FIG 9, wherein the cutting assembly is in a working state.

[0019] FIG 11 is a schematic view of a first cutting element and a second cutting element of the cutting assembly in FIG 9 in a height direction.

[0020] FIG 12 is a schematic view of a lawn mower applying the cutting assembly in FIG 9.

[0021] FIG 13 is an enlarged view of a part of the lawn mower in FIG 12.

[0022] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0023] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

[0024] Referring to FIGS. 1-2, a cutting assembly 100 includes a first cutting element 10 and a second cutting element 20.

[0025] The first cutting element 10 is connected with a drive shaft which drives the first cutting element 10 to rotate around a first axis 101. Specifically, the first cutting element 10 is formed with a mounting portion for fixing itself. More specifically, the first cutting element 10 is formed with a mounting hole 11 for mounting itself. The first cutting element 10 includes a first cutting edge 12, a first connecting arm 13 and a first blade wing 14.

[0026] The first connecting arm 13 is extended along a radial direction of the first axis 101. The first cutting edge 12 for cutting is disposed on the first connecting arm 13. The first connecting arm 3 2017100173 15 Feb 2017 13 is provided with a first reinforcing rib 15 for enhancing strength. The first blade wing 14 is formed on one side of the first cutting element 10 that is departed from the first cutting edge 12, which is used to increase air pressure making the debris and grass clippings suspend. The first blade wing 14 and the first cutting edge 12 are located on two sides of the first connecting arm 13 respectively. The first blade wing 14 has an extending direction which is inclined to the extending direction of the first cutting edge 12.

[0027] A second cutting element 20 is rotatably connected with the first cutting element 10 around a second axis 102. Specifically, the second axis 102 is arranged at a position different from the first axis 101. That is, the first and second axes 101, 102 don’t coincide. The second cutting element 20 is formed with a second cutting edge 21 for cutting. Specifically, the second cutting element 20 is rotatably connected with the first connecting arm 13. When the first cutting element 10 is rotated around the first axis 101, it drives the second cutting element 20 to rotate around the first axis 101 at the same time.

[0028] As shown in FIG. 3, the first cutting edge 12 has a first cutting area which is at least partially overlapped with a second cutting area of the second cutting edge 21. The cutting area is a projection of an area being passed by the cutting edge in a plane perpendicular to the axis during its rotation. So, the overlapped area can be cut twice by the first and second cutting edges 12, 21. The shaded part in FIG. 3 is the cutting area. Specifically, a difference between a first maximum radius of the first cutting area and a second maximum radius of the second cutting area is greater than or equal to 0mm and less than or equal to 10mm. More specifically, the first and second cutting areas are overlapped.

[0029] As shown in FIG. 4, when the first cutting element 10 is rotated around the first axis 101, the second cutting edge 21 is in front of the first cutting edge 12. That is, during cutting operation, the second cutting edge 21 cuts ahead of the first cutting edge 12. As shown in FIG. 4, the cutting assembly 100 is rotated along a direction of an arrow, namely, rotated clockwise. During rotation, the second cutting element 20 is located at a position relative to the first cutting element 10 under 4 2017100173 15 Feb 2017 the action of a centrifugal force shown in FIG. 4. Thus, during rotation, the second cutting edge 21 performs cutting operation firstly, and then the first cutting edge 12 performs secondary cutting operation.

[0030] A distance LI is defined between the first and second axes 101, 102. A ratio between the distance LI and the first maximum radius of the first cutting area of the first cutting edge 12 is greater than or equal to 0 and less than or equal to 2/3. Specifically, the ratio is greater than or equal to 0.2 and less than or equal to 0.5.

[0031] Referring to FIGS. 4 and 6, the first cutting edge 12 includes a first linear segment 121 having a straight-line shape. The second cutting edge 21 includes a second linear segment 211 also having a straight-line shape. As shown in FIG. 6, the first linear segment 121 is shorter than the second linear segment 211. Specifically, the second cutting edge 21 is constituted by the second linear segment 211, and the first cutting edge 12 is constituted by the first linear segment 121 and an arc segment.

[0032] As shown in FIG. 5, when the first cutting element 10 is rotated, a first projection of the first linear segment 121 and a second projection of the second linear segments 211 in the plane perpendicular to the first axis 101 are intersected obliquely. Specifically, an angel 0 between the first and second projections in the plane perpendicular to the first axis 101 is greater than or equal to 0° and less than or equal to 20° . The first linear segment 121 and the first blade wing 14 are located on the same side of the second linear segment 211.

[0033] The second cutting element 20 can be located above or below the first cutting element 10. As shown in FIG. 6, specifically, in a direction of the first axis 101, the second cutting edge 21 is located above the first cutting edge 12. The word ‘above’ in the description refers to a working state of the cutting assembly 100 or a height relative to the ground. Here, it also could be said that the first cutting edge 12 is located between the second cutting edge 21 and the ground. Specifically, the second cutting edge 21 is located above the first cutting edge 12, so that the second cutting edge 21 can cut the surface of the lawn firstly. And then the first cutting edge 12 performs the 5 2017100173 15 Feb 2017 secondary cutting operation, and the cutting depth is increased. A relatively smaller cutting depth is performed each time, so the cutting efficiency is improved and the cutting quality on the section is improved. When meeting a foreign matter, the second cutting edge 21 is rotated around the second axis 102 so as to have buffer effect. It avoids the striking force of the foreign matter from transferring to the second cutting element 20 and the drive shaft directly and rigidly, and the cutting assembly 100 and the drive shaft are avoided from damage.

[0034] As shown in FIG. 6, a distance L2 between the first and second linear segments 121, 211 is greater than or equal to 10mm and less than or equal to 15mm. The second cutting element 20 has flat up and low surfaces. The first blade wing 14 is protruded toward the second cutting element 20, and the first reinforcing rib 15 is protruded toward a direction departed from the second cutting element 20.

[0035] Referring to FIGS. 7-8, a lawn mower 200 includes a motor 201, a deck 202, a handle 203, a wheel assembly 204 and the cutting assembly 100. The motor 201 is used to drive the cutting assembly 100 to rotate. The deck 202 is formed with a cutting chamber 205, and the cutting assembly 100 can be rotated in the cutting chamber 205. The wheel assembly 204 can be rotated relative to the deck 202, which includes at least two wheels. The wheel assembly 204 supports the deck 202 and allows the deck 202 to move relative to the ground. As shown in FIG. 7, the second cutting element 20 is located between the first cutting element 10 and the motor 201 in the direction of the first axis 101.

[0036] Referring to FIGS. 1-2, the cutting assembly 100 further includes a third cutting element 30 having a third cutting edge 31 for cutting. The third cutting element 30 is rotatably connected with the first cutting element 10 around a third axis 103. Specifically, the third cutting element 30 has the same structure as the second cutting element 20.

[0037] The first cutting element 10 further includes a fourth cutting edge 42, a fourth connecting arm 43 and a fourth blade wing 44. The fourth connecting arm 43 is provided with a fourth reinforcing rib 45 for enhancing strength. 6 2017100173 15 Feb 2017 [0038] The fourth connecting arm 43 is extended along a direction departed from the first axis 101, and the extending direction of the fourth connecting arm 43 is opposite to the extending direction of the first connecting arm 13. The fourth cutting edge 42 for cutting is disposed on the fourth connecting arm 43.

[0039] The fourth blade wing 44 is formed on one side of the first cutting element 10 that is departed from the fourth cutting edge 42. The fourth blade wing 44 and the fourth cutting edge 42 are located on two sides of the fourth connecting arm 43 respectively. The extending direction of the fourth blade wing 44 is inclined to the extending direction of the fourth cutting edge 42. The second and third axes 102, 103 are symmetrical relative to the first axis 101.

[0040] Specifically, the first cutting element 10 is centrosymmetrical. The positional relationship between the second cutting element 20 and the first cutting edge 12, the first blade wing 14, the first connecting arm 13, the first reinforcing rib 15 is the same as the positional relationship between the third cutting element 30 and the fourth cutting edge 42, the fourth blade wing 44, the fourth connecting arm 43, the fourth reinforcing rib 45. The cutting assembly 100 is centrosymmetrical when it is rotated. The second and third cutting elements 20, 30 are located on the same side of the first cutting element 10.

[0041] As shown in FIG. 5, the first connecting arm 13 is extended along a direction Y, and the fourth connecting arm 43 is extended along a direction X. The two directions X, Y are opposite. A direction MN is perpendicular to the direction XY. The direction XY is commonly called a length direction, and the direction MN is commonly called a width direction. The first and fourth cutting edges 12, 42 are substantially parallel to the direction XY. The first cutting element 10 is formed with a middle plane 104 substantially parallel to the direction XY, and the first axis 101 is located in the middle plane 104. The second and third axes 102, 103 are located on two sides of the middle plane 104 respectively. The first and fourth cutting edges 12, 42 are located on the two sides of the middle plane 104 respectively. The second axis 102 and the first cutting edge 12 are located on the same side of the middle plane 104. The third axis 103 and the fourth cutting edge 42 are located on 7 2017100173 15 Feb 2017 the same side of the middle plane 104.

[0042] Referring to FIGS. 9-10, in another embodiment, a cutting assembly 100’ includes a first cutting element 10’ and a second cutting element 20’. The first cutting element 10’ is formed with a first cutting edge 12’ for cutting, and the second cutting element 20’ is formed with a second cutting edge 21 ’ for cutting.

[0043] The first cutting element 10’ is connected with a drive shaft which drives the first cutting element 10’ to rotate around a first axis 10Γ. Specifically, the first cutting element 10’ is formed with a mounting portion for fixing itself. More specifically, the first cutting element 10’ is formed with a mounting hole 11’ for mounting itself. The first cutting element 10’ is further formed with a first connecting arm 13’ extending along a direction that is departed from the first axis 10Γ. The first cutting edge 12’ is formed on the first connecting arm 13’. The first connecting arm 13’ is provided with a first reinforcing rib 15’ for enhancing strength.

[0044] A blade wing can be formed on the first cutting element 10’ or the second cutting element 20’. Certainly, both the first cutting element 10’ and the second cutting element 20’ can be formed with the blade wing.

[0045] The second cutting element 20’ is rotatably connected with the first cutting element 10’ around a second axis 102’. Specifically, the second axis 102’ is arranged at a position different from the first axis 10Γ. That is, the first and second axes 10Γ, 102’ don’t coincide. The second cutting element 20’ is formed with a second cutting edge 21’ for cutting. Specifically, the second cutting element 20’ is rotatably connected with the first connecting arm 13’. When the first cutting element 10’ is rotated around the first axis 10Γ, it drives the second cutting element 20’ to rotate around the first axis 101’ at the same time. The first cutting edge 12’ has a first cutting area which is at least partially overlapped with a second cutting area of the second cutting edge 21’. A difference between a first maximum radius of the first cutting area and a second maximum radius of the second cutting area is greater than or equal to 0mm and less than or equal to 10mm. More specifically, the first and second cutting areas are overlapped. 8 2017100173 15 Feb 2017 [0046] As shown in FIG. 10, when the first cutting element 10’ is rotated around the first axis 10Γ, the second cutting edge 2Γ is located in front of the first cutting edge 12’. The first cutting edge 12’ includes a first linear segment 121’ and, the second cutting edge 21’ includes a second linear segment 21Γ.

[0047] The second cutting element 20’ can be located above or below the first cutting element 10’. As shown in FIG. 11, specifically, the first cutting edge 12’ is located above the second cutting edge 21 ’ in a direction of the first axis 101 ’. So the first cutting edge 12’ can cut the surface of the lawn firstly. And then the second cutting edge 21’ performs the secondary cutting operation, and the cutting depth is increased. A relatively smaller cutting depth is performed each time, so the cutting efficiency is improved and the cutting quality on the section is improved.

[0048] Referring to FIGS. 12-13, a lawn mower 200’ includes a motor 20Γ, a deck 202’, a handle 203’, a wheel assembly 204’ and the cutting assembly 100’. The motor 201’ is used to drive the cutting assembly 100’ to rotate. The deck 202’ is formed with a cutting chamber 205’, and the cutting assembly 100’ can be rotated in the cutting chamber 205’. The wheel assembly 204’ can be rotated relative to the deck 202’, which includes at least two wheels. The wheel assembly 204’ supports the deck 202’ and allows the deck 202’ to move relative to the ground. Referring to FIGS. 12-13, the first cutting element 10’ is located between the second cutting element 20’ and the motor 201 ’ in the direction of the first axis 10Γ.

[0049] As shown in FIG. 13, the cutting assembly 100’ further includes a third cutting element 30’ having a third cutting edge 31’ for cutting. The third cutting element 30’ is rotatably connected with the first cutting element 10’ around a third axis 103’. Specifically, the third cutting element 30’ has the same structure as the second cutting element 20’. The second and third axes 102’, 103’ are symmetrical relative to the first axis 10Γ. Specifically, the first cutting element 10’ is centrosymmetrical. The cutting assembly 100’ is centrosymmetrical when it is rotated.

[0050] The above illustrates and describes basic principles, main features and advantages of the present invention. Those skilled in the art should appreciate that the above embodiments do not 9 2017100173 15 Feb 2017 limit the present invention in any form. Technical solutions obtained by equivalent substitution or equivalent variations all fall within the scope of the present invention. 10

Claims

CLAIMS What is claimed is:

1. A cutting assembly, comprising: a first cutting element driven to rotate around a first axis, the first cutting element being formed with a first cutting edge; and a second cutting element rotatably connected with the first cutting element around a second axis, the second cutting element being formed with a second cutting edge, wherein the second axis is arranged at a position different from the first axis, wherein the first cutting edge has a first cutting area and, the second cutting edge has a second cutting area, the first and second cutting areas are at least partially overlapped.
2. The cutting assembly of claim 1, wherein the first cutting edge comprises a first linear segment having a first projection in a plane perpendicular to the first axis and, the second cutting edge comprises a second linear segment having a second projection in the plane perpendicular to the first axis, the first projection is intersected obliquely with the second projection when the first cutting element is rotated.
3. The cutting assembly of claim 2, wherein an angle between the first and second projections is greater than or equal to 10° and less than or equal to 20° when the first cutting element is rotated.
4. The cutting assembly of claim 1, wherein the first cutting area has a first maximum radius and, the second cutting area has a second maximum radius, a difference between the first and second maximum radiuses is greater than or equal to 0mm and less than or equal to 10mm.
5. The cutting assembly of claim 1, wherein the first cutting edge comprises a first linear segment and, the second cutting edge comprises a second linear segment, the first linear segment is shorter than the second linear segment.
6. The cutting assembly of claim 1, wherein when the first cutting element is rotated around the first axis, the second cutting edge is located in front of the first cutting edge.
7. The cutting assembly of claim 1, wherein when the first cutting element is rotated around the first axis, the first cutting edge is located behind the second cutting edge.
8. The cutting assembly of claim 1, wherein the first cutting edge is located above the second cutting edge in a direction of the first axis of the first cutting element.
9. The cutting assembly of claim 1, wherein the second cutting edge is located above the first cutting edge in a direction of the first axis of the first cutting element.
10. A lawn mower, comprising: a motor; a deck being formed with a cutting chamber; and a cutting assembly driven by the motor and accommodated in the cutting chamber, the cutting assembly comprising: a first cutting element driven to rotate around a first axis, the first cutting element being formed with a first cutting edge; and a second cutting element rotatably connected with the first cutting element around a second axis, the second cutting element being formed with a second cutting edge, wherein the second axis is arranged at a position different from the first axis, wherein the first cutting edge has a first cutting area and, the second cutting edge has a second cutting area, the first and second cutting areas are at least partially overlapped.