Grass trimmer

Patent metadata

Field	Value
Publication number	US-11818979-B2
Application number	US-201916577063-A
Country	US
Kind code	B2
Filing date	Sep 20, 2019
Priority date	Jan 22, 2016
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

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 member, the spool is used to wind a cutting line, and the line holding member 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 and the line holding member to make the spool and the line holding member rotate relatively so that the cutting line is wound on the spool automatically.

First claim

What is claimed is:

1. A grass trimmer, comprising:
a trimming head; and
a motor for driving the trimming head;
wherein the trimming head comprises:
a housing comprising a housing cavity;
a plurality of eyelet members connected to the housing, each eyelet member comprising an outer aperture for allowing a cutting line to be inserted from outside of the housing into the housing cavity;
a spool at least partially disposed in the housing cavity and rotatable relative to the housing about a central axis, wherein the spool comprises inner apertures for the cutting line to be inserted into the spool; and
a spring disposed between the housing and the spool;
wherein the spool has a line-loading position relative to the housing where at least one of the outer apertures is aligned with one of the inner apertures;
wherein the spool comprises a plurality of first engaging portions arranged in a circumferential direction around the central axis, the housing comprises a plurality of first matching portions corresponding to the plurality of first engaging portions, each of the plurality of first matching portions comprises a first cam surface, and each of the plurality of first engaging portions comprises a second cam surface; and
wherein the spring is configured to drive the first cam surface to move relative to the second cam surface to cause the spool to rotate to the line-loading position relative to the housing.

2. The grass trimmer of claim 1 , wherein:
each of the plurality of first matching portions comprises a first positioning surface;
each of the plurality of first engaging portions comprises a second positioning surface; and
the spring is configured to apply a force to the spool or the housing to bring the first positioning surface and the second positioning surface closer to each other.

3. The grass trimmer of claim 2 , wherein the spool comprises:
an upper winding portion for winding the cutting line;
a lower winding portion for winding the cutting line;
an intermediate flange portion disposed between the upper winding portion and the lower winding portion, the intermediate flange portion comprising the inner apertures;
an upper flange portion connected to an upper end of the upper winding portion; and
a lower flange portion connected to a lower end of the lower winding portion;
wherein the plurality of first engaging portions are disposed on the upper flange portion or the lower flange portion.

4. The grass trimmer of claim 3 , wherein each eyelet member protrudes at least partially toward the spool, and a distance between each eyelet member and the intermediate flange portion is less than or equal to 3 mm.

5. The grass trimmer of claim 1 , wherein the spool comprises at least one passage for the cutting line to pass through the spool, the ends of the at least one passage are defined as the inner apertures, and the at least one passage is configured to extend along a curve.

6. The grass trimmer of claim 5 , wherein the spool comprises:
an upper spool comprising an upper winding portion for winding the cutting line; and
a lower spool comprising a lower winding portion for winding the cutting line;
wherein the upper spool and the lower spool are combined to form the at least one passage.

7. The grass trimmer of claim 5 , wherein the grass trimmer has an auto-winding mode, and in the auto-winding mode, the spool is driven by the motor to rotate so as to wind the cutting line around the spool automatically.

8. A trimming head, comprising:
a housing;
eyelet members mounted to the housing, the eyelet members comprising outer apertures for allowing a cutting line to be inserted from outside of the housing into the housing;
a spool rotatable relative to the housing about a central axis, the spool comprising inner apertures for the cutting line to be inserted into the spool; and
a driving member configured to apply a force to the housing or the spool;
wherein the spool has a line-loading position relative to the housing where at least one of the outer apertures is aligned with one of the inner apertures; and
wherein the spool comprises at least one first engaging portion arranged in a circumferential direction around the central axis, the housing comprises at least one first matching portion corresponding to the at least one first engaging portion, the driving member is a spring disposed between the housing and the spool, and the spring is configured to drive the at least one first engaging portion to move relative to the at least one first matching portion to cause the spool to rotate to the line-loading position relative to the housing.

9. A trimming head, comprising:
a housing assembly comprising a housing cavity and outer apertures for allowing a cutting line to be inserted from outside of the housing assembly into the housing cavity; and
a spool at least partially disposed in the housing cavity and rotatable relative to the housing assembly about a central axis, wherein the spool comprises inner apertures for the cutting line to be inserted into the spool; and
wherein the spool has a line-loading position relative to the housing assembly where at least one of the outer apertures is aligned with one of the inner apertures; and
wherein the trimming head further comprises a spring disposed between the housing assembly and configured to apply a force to the spool or the housing assembly to drive a first engagement tooth of the spool relative to a first matching tooth of the housing assembly to drive the spool to rotate to the line-loading position relative to the housing assembly.

10. The trimming head of claim 9 , wherein the spool comprises a plurality of first engaging teeth arranged in a circumferential direction around the central axis, the housing assembly comprises a plurality of first matching teeth corresponding to the first engaging teeth, each of the first matching teeth comprises a first positioning surface, each of the first engaging teeth comprises a second positioning surface, and the first positioning surface is in contact with the second positioning surface when the spool in the line-loading position relative to the housing.

11. The trimming head of claim 10 , wherein the spring is configured to apply a force to the spool or the housing assembly to bring the first positioning surface and the second positioning surface closer to each other.

12. The trimming head of claim 11 , wherein each of the first matching teeth comprises a first inclined surface inclined to a plane perpendicular to the central axis, each of the first engaging teeth comprises a second inclined surface inclined to the plane perpendicular to the central axis, the first inclined surface and the first positioning surface are located on two sides of the first matching teeth, the second inclined surface and the second positioning surface are located on two sides of the first engaging teeth, and the first inclined surface is in contact with the second inclined surface when the first positioning surface is in contact with the second positioning surface.

13. The trimming head of claim 11 , wherein the spool comprises:
an upper winding portion for winding the cutting line;
a lower winding portion for winding the cutting line;
an intermediate flange portion disposed between the upper winding portion and the lower winding portion, the intermediate flange portion comprising the inner apertures;
an upper flange portion connected to an upper end of the upper winding portion; and
a lower flange portion connected to a lower end of the lower winding portion;
wherein the first engaging teeth are disposed on the upper flange portion or the lower flang

Assignees

• Nanjing Chervon Ind Co Ltd
• Chervon Hk Ltd

Inventors

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

Classifications

• A01D34/4166 Primary

  Mounting or replacement of the lines · CPC title

• A01D34/4162

  automatically · CPC title

• A01D2101/00

  Lawn-mowers · CPC title

• A01D34/4163

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