Trimmer Line Cutting Head for Mounting on a Drive Shaft of a Trimmer

Patent metadata

Field	Value
Publication number	US-2021059115-A1
Application number	US-202017001734-A
Country	US
Kind code	A1
Filing date	Aug 25, 2020
Priority date	Aug 30, 2019
Publication date	Mar 4, 2021
Grant date	—

Abstract

A trimmer line cutting head has a trimmer line spool rotatably supported about an axis of rotation and disposed slidably between housing and housing cover along the axis of rotation. A spring element pretensions the trimmer line spool in an operating position of the trimmer line cutting head. An indexing device has a terminal stop connecting the trimmer line spool in the operating position to the housing in fixed connection for common rotation of trimmer line spool and housing. By applying an actuating force to the indexing device, the trimmer line spool is adjustable from the operating position axially into an inoperative state of the trimmer line cutting head for paying out trimmer line. The indexing device has a rotational stop formed in a slot in a wall of the trimmer line spool and limiting rotation of the trimmer line spool relative to the housing in the inoperative state.

First claim

What is claimed is:

1 . A trimmer line cutting head comprising:
a housing; a housing cover connected to the housing; a trimmer line spool comprising a spool wall, wherein the trimmer line spool is rotatably supported about an axis of rotation in the housing and is disposed slidably between the housing and the housing cover in a direction of the axis of rotation; a spring element arranged in the housing and pretensioning the trimmer line spool in an operating position of the trimmer line cutting head; an indexing device comprising a terminal stop, wherein the terminal stop connects the trimmer line spool in the operating position to the housing in a fixed connection for a common rotation of the trimmer line spool with the housing; wherein, by applying an actuating force acting on the indexing device, the trimmer line spool is adjustable from the operating position in a direction of the axis of rotation into an inoperative state of the trimmer line cutting head for paying out a trimmer line wound onto the trimmer line spool; wherein the indexing device further comprises a rotational stop limiting a rotation of the trimmer line spool relative to the housing in the inoperative state; wherein the rotational stop is formed in a slot in the spool wall of the trimmer line spool.

2 . The trimmer line cutting head according to claim 1 , further comprising an engagement element arranged at the housing and configured to interact with the slot in the spool wall in the inoperative state.

3 . The trimmer line cutting edge according to claim 1 , wherein the slot in the spool wall is an opening in the spool wall.

4 . The trimmer line cutting head according to claim 1 , wherein the spool wall of the trimmer line spool is an upper spool wall neighboring the housing.

5 . The trimmer line cutting head according to claim 1 , wherein the slot extends about an angle section about the axis of rotation in the form of a circular arc, wherein the angle section amounts to between 30° and 70°.

6 . The trimmer line cutting head according to claim 1 , wherein the rotational stop comprises a structural raised portion at the slot.

7 . The trimmer line cutting head according to claim 1 , wherein the trimmer line spool further comprises a hub segment configured to rotatably support the trimmer line spool in the housing and further comprises a trimmer line chamber segment adjoining the hub segment and configured to accommodate the trimmer line, wherein the trimmer line chamber segment comprises the spool wall with the slot.

8 . The trimmer line cutting head according to claim 1 , wherein the terminal stop of the indexing device is arranged at the housing cover and wherein the indexing device further comprises a counter stop provided at the trimmer line spool and configured to interact with the terminal stop.

9 . The trimmer line cutting head according to claim 8 , wherein the counter stop in the operating position engages the terminal stop to produce the fixed connection for common rotation of the trimmer line spool with the housing.

10 . The trimmer line cutting head according to claim 1 , further comprising an engagement element arranged at the housing and configured to interact with the slot in the spool wall in the inoperative state, wherein the indexing device is configured such that, when the indexing device is acted on by the actuating force, the trimmer line spool is rotated relative to the housing about a first rotational angle into a first section of the inoperative state, wherein the first rotational angle is defined by the engagement element hitting the rotational stop.

11 . The trimmer line cutting head according to claim 10 , wherein the indexing device further comprises a counter stop provided at the trimmer line spool and configured to interact with the terminal stop, wherein the trimmer line spool is configured to rotate about a second rotational angle relative to the housing from the first section of the inoperative state until the counter stop hits the terminal stop, wherein a total rotational angle of the trimmer line spool is a sum of the first rotational angle and of the second rotational angle.

12 . The trimmer line cutting head according to claim 1 , further comprising an actuating element, wherein the actuating force is applied by the actuating element to the indexing device, wherein the actuating element extends from an opening of the housing cover in a direction away from the housing.

13 . The trimmer line cutting head according to claim 1 , wherein the trimmer line spool is pretensioned by the spring element against the housing cover.

14 . The trimmer line cutting head according to claim 1 , wherein the slot is delimited by a circumferential wall surrounding the slot.

15 . The trimmer line cutting edge according to claim 1 , wherein the trimmer line spool comprises a trimmer line channel configured to insert the trimmer line.

16 . The trimmer line cutting edge according to claim 1 , wherein the trimmer line channel is configured to allow the trimmer line to pass through the trimmer line channel.

Assignees

• Stihl Ag & Co Kg Andreas

Inventors

• Rethaber Achim

Classifications

• A01D34/4165

  Mounting of the cutter head · CPC title

• A01D34/4166 Primary

  Mounting or replacement of the lines · CPC title

• A01D34/4161 Primary

  Means for feeding cutter line · CPC title

• A01D34/4163 Primary

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

• A01D34/46

  hand-guided by a walking operator · CPC title