Filament cutterhead for a brushcutter

Patent metadata

Field	Value
Publication number	US-9693500-B2
Application number	US-201514697473-A
Country	US
Kind code	B2
Filing date	Apr 27, 2015
Priority date	Apr 26, 2014
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A filament cutterhead for a brushcutter is able to be driven in a rotatable manner during operation in a rotational direction about a rotational axis. The filament cutterhead has a base body on which at least one cutting filament is retained and which has a lower face facing the ground during operation. The cutting filament extends from an outer face of the base body through an opening as far as an inner region of the base body which is open toward the lower face of the base body. In order to achieve a low degree of soiling of the filament cutterhead during operation, a shield element is provided in the inner region and the leading portion of the cutting filament in the inner region is arranged in the slipstream of the shield element relative to the rotational direction.

First claim

What is claimed is:

1. A cutterhead for a brushcutter, the cutterhead being rotatably driveable in a rotational direction about a rotational axis during operation, the cutterhead comprising:
a cutting filament;
a clamping arrangement;
a base body having a lower face and being configured to hold said cutting filament via said clamping arrangement;
said lower face being configured to face toward the ground during operation;
said base body defining an outer face and having an inner region open to said lower face thereof;
said base body further having an opening for accommodating said cutting filament;
said cutting filament extending from said outer face of said base body through said opening to said inner region;
said inner region being arranged radially within said clamping arrangement with respect to the rotational axis;
a shield element disposed in said inner region and defining a wind shadow;
said cutting filament having a segment running in said inner region; and,
said segment being arranged in said wind shadow of said shield element with respect to the rotational direction.

2. The cutterhead of claim 1 , wherein:
said segment of said cutting filament has a leading longitudinal side during operation; and,
said shield element is arranged adjacent to said leading longitudinal side of said segment.

3. The cutterhead of claim 1 , wherein said shield element is a shield wall.

4. The cutterhead of claim 1 , wherein:
said lower face defines a plane;
said base body has a peripheral wall delimiting said inner region radially outwardly with respect to the rotational axis; and,
said peripheral wall has at least one section expanding in a direction toward said plane.

5. The cutterhead of claim 4 , wherein:
said inner region defines a circularly shaped cross-section having a diameter (a, b); and,
said diameter (a, b) is measured perpendicularly to the rotational axis and increases in a direction toward said plane of said lower face of said base body.

6. The cutterhead of claim 1 , wherein:
said cutting filament is held on said base body via said clamping arrangement; and,
said clamping arrangement is configured to block a movement of said cutting filament to an outer side of said base body and to allow a movement of said cutting filament in the direction of said inner region.

7. The cutterhead of claim 1 , wherein:
said base body defines a top surface of said inner region;
said shield element and said top surface conjointly define a receptacle for said cutting filament; and,
said receptacle defines a trailing side during operation and is at least partially open toward said trailing side.

8. The cutterhead of claim 1 , wherein said segment is arranged entirely in a slipstream of said shield element with respect to the rotational direction.

9. A cutterhead for a brushcutter, the cutterhead being rotatably driveable in a rotational direction about a rotational axis during operation, the cutterhead comprising:
a cutting filament;
a base body having a lower face and being configured to hold said cutting filament;
said lower face being configured to face toward the ground during operation;
said base body defining an outer face and having an inner region open to said lower face thereof;
said base body further having an opening for accommodating said cutting filament;
said cutting filament extending from said outer face of said base body through said opening to said inner region;
a shield element disposed in said inner region and defining a wind shadow;
said cutting filament having a segment running in said inner region;
said segment being arranged in said wind shadow of said shield element with respect to the rotational direction;
said shield element having a lower edge facing said lower face of said base body;
said cutting filament defining a longitudinal direction; and,
said lower edge and said longitudinal direction conjointly defining an angle of at most approximately 30°.

10. A cutterhead for a brushcutter, the cutterhead being rotatably driveable in a rotational direction about a rotational axis during operation, the cutterhead comprising:
a cutting filament;
a base body having a lower face and being configured to hold said cutting filament;
said lower face being configured to face toward the ground during operation;
said base body defining an outer face and having an inner region open to said lower face thereof;
said base body further having an opening for accommodating said cutting filament;
said cutting filament extending from said outer face of said base body through said opening to said inner region;
a shield element disposed in said inner region and defining a wind shadow;
said cutting filament having a segment running in said inner region;
said segment being arranged in said wind shadow of said shield element with respect to the rotational direction;
said shield element having a lower edge facing said lower face of said base body;
said lower face of said base body defining a plane;
said lower edge and said plane conjointly defining a distance (o) therebetween;
said segment of said cutting filament and said lower face conjointly defining a distance (p) therebetween; and,
said distance (o) defined between said lower edge and said plane being less than said distance (p) defined between said segment and said lower face.

11. The cutterhead of claim 10 , wherein:
said cutting filament has a leading longitudinal side with respect to the rotational direction;
said leading longitudinal side and said shield element conjointly define a distance (c, k, m) therebetween; and,
said distance (c, k, m) defined between said leading longitudinal side and said shield element is at most five times the difference between said distance (p) defined between said segment and said lower face and said distance (o) defined between said lower edge and said plane.

12. A cutterhead for a brushcutter, the cutterhead being rotatably driveable in a rotational direction about a rotational axis during operation, the cutterhead comprising:
a cutting filament;
a base body having a lower face and being configured to hold said cutting filament;
said lower face being configured to face toward the ground during operation;
said base body defining an outer face and having an inner region open to said lower face thereof;
said base body further having an opening for accommodating said cutting filament;
said cutting filament extending from said outer face of said base body through said opening to said inner region;
a shield element disposed in said inner region and defining a wind shadow;
said cutting filament having a segment running in said inner region;
said segment being arranged in said wind shadow of said shield element with respect to the rotational direction;
said base body having a side facing away from said lower face;
said inner region being delimited with respect to said side facing away from said lower face by a top surface;
said top surface having a spiral-shaped section arranged ahead of said shield element and bordering on said shield element;
said lower face defining a plane; and,
said plane defined by said lower face and said top surface conjointly defining a distance (e, f, g, h, i) therebetween which increases in the rotational direction in said spiral-shaped section.

13. The cutterhead of claim 12 comprising:
two cutting filaments arranged at an angular distance (γ) to each other;
said spiral-shaped section extending over an angular region (α, β) about the rotational axis; and,
said angular region (α, β) being at least 30% of said angular distance (γ).

14

Assignees

• Stihl Ag & Co Kg Andreas

Inventors

• Guenther David
• Hauber Thomas

Classifications

• A01D34/416 Primary

  Flexible line cutters · CPC title

• A01D34/4167 Primary

  Protection devices · CPC title

• A01D34/4165

  Mounting of the cutter head · CPC title