Grass trimmer, operating method thereof and control method thereof

Patent metadata

Field	Value
Publication number	US-10264725-B2
Application number	US-201715839257-A
Country	US
Kind code	B2
Filing date	Dec 12, 2017
Priority date	Jan 22, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A grass trimmer includes a trimming head, a driving device for driving the trimming head to rotate so as to cut vegetation and an operating device for a user to operate so as to control the driving device. The trimming head includes a spool and a line holding element, the spool is used to wind a trimming line, and the line holding element is formed with a line holding structure. The driving device includes a motor. The grass trimmer has an auto-winding mode. In the auto-winding mode, the motor drives at least one of the spool or the line holding element to make the spool and the line holding element rotate relatively so that the trimming line is wound on the spool automatically.

First claim

What is claimed is:

1. A grass trimmer, comprising:
a trimming head;
a motor connected with the trimming head;
an operating device or switch operably coupled to the motor; and
a power supply for supplying power to the motor;
wherein the trimming head comprises a spool and a line holding element, the spool is used to wind a trimming line and the line holding element is formed with a line holding structure,
wherein the grass trimmer has a cutting mode and an auto-winding mode controllable by the operating device or switch, in the cutting mode, the trimming head is driven by the motor to rotate so as to cut vegetation, and in the auto-winding mode, the line holding structure holds the trimming line while at least one of the spool or the line holding element is driven by the motor for producing relative rotation between the spool and the line holding element thereby winding the trimming line around the spool, and
wherein the operating device or switch is operable to control the motor and actuate the auto-winding mode, thereby winding the trimming line around or onto the spool.

2. The grass trimmer of claim 1 , wherein the grass trimmer further comprises a damping device for decreasing a rotation speed of the spool or decreasing a rotation speed of the line holding element so as to produce a rotation speed difference between the spool and the line holding element in the auto-winding mode.

3. The grass trimmer of claim 2 , wherein the damping device comprises a damping element for producing a resistance force on the spool to decrease the rotation speed of the spool or prevent the spool from rotating.

4. The grass trimmer of claim 2 , wherein the damping device comprises a damping element for producing a resistance force on the line holding element to decrease the rotation speed of the line holding element or prevent the line holding element from rotating.

5. The grass trimmer of claim 1 , wherein the rotation speed of the motor in the cutting mode is greater than the rotation speed of the motor in the auto-winding mode.

6. The grass trimmer of claim 1 , wherein in the cutting mode, the spool and the line holding element are rotated synchronously, the trimming head is rotated in a first direction in the cutting mode, and in the auto-winding mode, one of the spool and the line holding element is rotated relative to the other in a second direction opposite to the first direction.

7. A grass trimmer, comprising:
a trimming head comprising a spool and a head housing, the spool is used to wind a trimming line, and the head housing defining at least one outer aperture allowing the trimming line to pass through;
a driving device for supplying power to the trimming head; and
an operating device or switch coupled to the driving device and being operable to control the driving device;
wherein the grass trimmer has a cutting mode and an auto-winding mode controllable by the operating device or switch, the grass trimmer further comprises a damping device for preventing the head housing from rotating in the auto-winding mode, in the cutting mode, the trimming head is driven by the driving device to rotate, and in the auto-winding mode, the spool is driven by the driving device to rotate so as to wind the trimming line onto the spool.

8. The grass trimmer of claim 7 , wherein the damping device is a one-way bearing.

9. The grass trimmer of claim 7 , wherein the operating device comprises a first operating element for activating the driving device so as to make the grass trimmer be in the cutting mode and a second operating element for a user to operate so as to choose or start the auto-winding mode.

10. The grass trimmer of claim 7 , wherein the driving device comprises a motor, in the cutting mode, the spool and the head housing are driven by the motor to rotate synchronously, the trimming head is rotated in a first direction in the cutting mode, and in the auto-winding mode, one of the spool and the head housing is rotated by the motor to rotate relative to the other in a second direction opposite to the first direction.

11. The grass trimmer of claim 10 , wherein the motor is rotated forwardly in the cutting mode and rotated reversely in the auto-winding mode.

12. The grass trimmer of claim 10 , wherein the motor is rotated at a first speed in the cutting mode and rotated at a second speed in the auto-winding mode with the second speed being different from the first speed.

13. The grass trimmer of claim 10 , wherein the motor is rotated forwardly at a higher first speed in the cutting mode and rotated reversely at a lower second speed in the auto-winding mode.

14. The grass trimmer of claim 13 , wherein a ratio between the first speed and the second speed is greater than or equal to 5 and less than or equal to 300.

15. The grass trimmer of claim 7 , wherein in the auto-winding mode, the spool has a rotation speed which is greater than or equal to 300 rpm and less than or equal to 800 rpm.

16. The grass trimmer of claim 7 , wherein in the auto-winding mode, the spool has a rotation speed which is greater than or equal to 30 rpm and less than or equal to 600 rpm.

17. The grass trimmer of claim 16 , wherein in the auto-winding mode, the rotation speed of the spool is greater than or equal to 60 rpm and less than or equal to 300 rpm.

18. A grass trimmer, comprising:
a trimming head comprising a spool for winding a trimming line and a line holding element, the line holding element is formed with a line holding structure;
a driving device for supplying power to the trimming head; and
an operating device or switch coupled to the driving device and being operable to control the driving device,
wherein the grass trimmer has a cutting mode and an auto-winding mode controllable by the operating device or switch,
wherein in the auto-winding mode, at least one of the spool or the line holding element is driven by the driving device to rotate and wind the trimming line onto the spool, the line holding structure is associated with the trimming line while the at least one of the spool or the line holding element is driven by the driving device to produce relative rotation between the spool and the line holding element; and
wherein in the cutting mode, the trimming head is driven by the driving device to rotate.

19. The grass trimmer of claim 18 , wherein the rotation direction of the spool in the auto-winding mode is opposite to the rotation direction of the trimming head in the cutting mode, the rotation speed of the spool in the auto-winding mode is less than the rotation speed of the trimming head in the cutting mode.

20. The grass trimmer of claim 18 , wherein the grass trimmer further comprises a damping device for preventing the line holding element from rotating and allowing the spool to rotate in the auto-winding mode.

Assignees

• Nanjing Chervon Ind Co Ltd
• Chervon Hk Ltd

Inventors

• Guo Jianpeng
• Li Maohui
• Nie Fangjie
• Yamaoka toshinari

Classifications

• A01D34/4165

  Mounting of the cutter head · CPC title

• A01D34/4166 Primary

  Mounting or replacement of the lines · CPC title

• A01D2101/00

  Lawn-mowers · CPC title

• A01D34/4163 Primary

  by triggered line feedout, e.g. bump-feeding · CPC title

• A01D34/416 Primary

  Flexible line cutters · CPC title