String trimmer assembly and trimmer head for use with same

Patent metadata

Field	Value
Publication number	US-12376515-B2
Application number	US-202217855183-A
Country	US
Kind code	B2
Filing date	Jun 30, 2022
Priority date	Jun 30, 2021
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A string trimmer assembly includes a trimmer head rotatably driven by a drive shaft and defining a cavity, a spool supported in the cavity of the trimmer head and operable to support line to be dispensed, which is dispensable though an opening in the trimmer head, and a bump protruding from a distal end of the trimmer head. The bump includes a wear surface on a terminating end of the bump, and the wear surface and the opening define a cutting height.

First claim

What is claimed is:

1. A string trimmer assembly comprising:
a trimmer head rotatably driven by a drive shaft, the trimmer head defining a cavity;
a spool supported in the cavity of the trimmer head and operable to support line to be dispensed, the line dispensable though an opening in the trimmer head; and
a bump protruding from a distal end of the trimmer head;
wherein the bump includes a wear surface on a terminating end of the bump,
wherein the wear surface and the opening defining a cutting height;
wherein the trimmer bead is bumpable against a surface to dispense additional line from the opening, and
wherein the cutting height remains constant.

2. The string trimmer assembly of claim 1 , further comprising
a drive shaft configured to be driven by a motor; and
a housing,
wherein the trimmer head is configured to be mounted to the drive shaft via the spool.

3. The string trimmer assembly of claim 2 , wherein the wear surface of the trimmer head is bumpable against the surface to inhibit damage to the housing.

4. The string trimmer assembly of claim 1 , wherein the bump is dome shaped.

5. The string trimmer assembly of claim 4 , wherein the bump includes an annular chamfered edge extending between the terminating end and a body of the bump.

6. The string trimmer assembly of claim 5 , wherein the annular chamfered edge is configured to contact the surface.

7. A trimmer head for use with a string trimmer assembly, the trimmer head comprising:
a top plate;
a body, the body and the top plate defining a cavity;
a spool supported in the cavity and operable to support line to be dispensed, the line dispensable though an opening in the body;
a nut coupled to the spool;
a retainer coupled to the body, the retainer configured to accommodate axial and rotational play between the spool and the body; and
a bump protruding from a distal end of the body, the bump including a wear surface on a terminating end thereof, the wear surface and the opening defining a cutting height,
wherein the wear surface of the bump is bumpable against a surface to dispense additional line from the opening; and
wherein the cutting height remains constant.

8. The trimmer head of claim 7 , wherein the wear surface of the bump is bumpable against the surface to move the body axially toward the top plate and momentarily inhibit relative axial and rotational play between the top plate and the body, thereby rotating the spool relative to the body and dispensing the additional line from the opening.

9. The trimmer head of claim 2 , wherein the wear surface is bumpable against the surface to inhibit damage to the body.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Cholst Beth E

Classifications

• A01D34/4167

  Protection devices · CPC title

• A01D34/4165

  Mounting of the cutter head · CPC title

• A01D34/4163 Primary

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

• A01D34/416 Primary

  Flexible line cutters · CPC title