IP Library Granted Patent US 12,213,403
Granted Patent B2
US 12,213,403 · App. 17/410,094 · Granted Feb 4, 2025

String trimmer head and spool

Inventors: Beth E. Cholst (Wauwatosa, WI); Troy C. Thorson (Cedarburg, WI)
Assignee: MILWAUKEE ELECTRIC TOOL CORPORATION
A01D34/4166A01D34/4163A01D34/4165
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Quick Facts
Patent No.
US 12,213,403
App. No.
17/410,094
Granted
Feb 4, 2025
Kind
B2
Abstract

A spool and a trimmer head. The trimmer head includes a housing defining a cavity and rotatable about an axis. A spool is supported in the cavity and operable to support line to be dispensed. The spool is movable along the axis relative to the housing, and the spool and the housing define cooperating conical surfaces to center the spool during movement of the spool toward and in a position relative to the housing.

Claims (26)

1. A trimmer head comprising:

a housing assembly including a housing portion at least partially defining a cavity, the housing assembly rotatable about an axis and including a retainer selectively coupled to the housing portion, the retainer defining a first conical surface; and

a spool supported in the cavity and operable to support line to be dispensed, the spool being movable along the axis relative to the housing assembly, the spool defining a central portion and a second conical surface which extends continuously around the central portion, wherein the second conical surface cooperates with the first conical surface to center the spool during movement of the spool toward and in a position relative to the housing assembly;

wherein:

the retainer and the housing portion capture the spool, and

the spool and the retainer define cooperating teeth configured to drivingly couple the spool with the retainer; and

wherein the spool comprises:

the central portion extending along the axis,

a first flange proximate one end of the central portion,

a second flange proximate an opposite end of the central portion, and

an intermediate flange between the first flange and the second flange, the intermediate flange being in a flange plane, the flange plane being oriented non-perpendicular to the axis, wherein the second conical surface is positioned adjacent the second flange.

2. The trimmer head of claim 1 , wherein the housing assembly further includes a bump knob cooperating with the housing portion to define the cavity, the bump knob being rotationally and axially fixed to the spool.

3. The trimmer head of claim 1 , wherein the intermediate flange defines a tube extending transverse to the axis and through the central portion, the tube being configured to receive the line to be dispensed, the tube extending along a tube axis in a tube plane, the tube plane being perpendicular to the axis.

4. The trimmer head of claim 1 , further comprising a biasing member positioned between the housing assembly and the spool and operable to bias the spool toward the position.

5. A trimmer head comprising:

a housing assembly defining a cavity and rotatable about an axis, the housing assembly defining a first conical surface; and

a spool supported in the cavity for movement along the axis relative to the housing, the spool including,

a central portion,

a first flange proximate one end of the central portion and positioned in a first plane,

a second flange proximate an opposite end of the central portion and positioned in a second plane, parallel to the first plane,

an intermediate flange extending around the central portion between the first flange and second flange, the intermediate flange being in a third plane oriented at an oblique angle relative to the first plane, and

a second conical surface which cooperates with the first conical surface to center the spool during movement of the spool.

6. The trimmer head of claim 5 , wherein the second conical surface is positioned on the central portion and extends continuously around the central portion.

7. The trimmer head of claim 5 , wherein the second conical surface is positioned at a junction of the central portion and one of the first flange and the second flange.

8. The trimmer head of claim 5 , wherein the intermediate flange defines a tube extending transverse to the axis and through the central portion, the tube being configured to receive a line, the tube extending along a tube axis in a fourth plane, the fourth plane being parallel to the second plane.

9. The trimmer head of claim 5 , wherein the spool and the housing assembly define cooperating teeth configured to drivingly couple the spool with the housing assembly.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 25, 2021
From: CHOLST, BETH E.; THORSON, TROY C.
To: MILWAUKEE ELECTRIC TOOL CORPORATION
Reel/Frame 057281/0074 →
Continuity (3)
Continuation 16129504 · Sep 12, 2018
Provisional Application 62557636 · Sep 12, 2017
Related Publication 20210378173A1 · Dec 9, 2021
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Cited By (1)
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