Handheld work apparatus

Patent metadata

Field	Value
Publication number	US-9623547-B2
Application number	US-201414341997-A
Country	US
Kind code	B2
Filing date	Jul 28, 2014
Priority date	Jul 27, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A handheld work apparatus has a motor unit comprising a drive motor. The drive motor drives a tool of the work apparatus, for example a saw chain. The apparatus has a grip unit with a handle that is vibrationally decoupled from the motor unit via an antivibration element. The antivibration element is connected to a first component of the grip unit via a holding device and a second component of the motor unit via a holding element. Arranged in the connection of the first component to the second component through the antivibration element is a predetermined breaking point formed in a third component that is replaceable independently of the first component and the second component. The strength of the connection of the first component to the second component through the antivibration element is lowest at this predetermined breaking point.

First claim

The invention claimed is:

1. A handheld work apparatus comprising:
a motor unit comprising a drive motor, wherein the drive motor drives a tool of the work apparatus;
a grip unit comprising a handle, wherein the grip unit is vibrationally decoupled from the motor unit via an antivibration element, wherein the antivibration element is connected to a first component of the grip unit via a holding device, and wherein the antivibration element is connected to a second component of the motor unit via a holding element;
a predetermined breaking point, wherein the predetermined breaking point is formed in a third component that is replaceable independently of the first component and the second component, wherein the predetermined breaking point is arranged in the connection of the first component to the second component through the antivibration element, and wherein the strength of the connection of the first component to the second component through the antivibration element is lowest at the predetermined breaking point.

2. The work apparatus according to claim 1 ,
wherein the predetermined breaking point is formed by a notch.

3. The work apparatus according to claim 2 ,
wherein a longitudinal center axis of the antivibration element extends through the notch in the unloaded state of the antivibration element.

4. The work apparatus according to claim 2 ,
wherein the depth of the notch is at least 20% of the width of a portion of the third component adjacent to the notch, wherein both the depth and the width are measured in the direction parallel to the depth of the notch.

5. The work apparatus according to claim 4 ,
wherein the holding element has a receptacle for a breakaway coupling.

6. The work apparatus according to claim 4 ,
wherein the holding device comprises a threaded portion screwed into the helical spring.

7. The work apparatus according to claim 4 ,
wherein the grip unit comprises an operating medium tank, which forms the first component to which the antivibration element is secured, and wherein the holding device is formed on the operating medium tank.

8. The work apparatus according to claim 7 ,
wherein the holding device is arranged on a top side of the operating medium tank, and wherein the top side is directed upward in a resting position of the work apparatus.

9. The work apparatus according to claim 7 ,
wherein the operating medium tank is arranged next to a rear handle of the work apparatus.

10. The work apparatus according to claim 1 ,
wherein the holding element comprises the predetermined breaking point, wherein the holding element is fixed releasably to the motor unit, and wherein the strength of the holding element at the predetermined breaking point is lower than the strength of the holding device.

11. The work apparatus according to claim 10 ,
wherein the holding element comprises a first fastening portion for fastening to the motor unit and a second fastening portion for fastening to a damping element of the antivibration element.

12. The work apparatus according to claim 11 ,
wherein the predetermined breaking point is arranged between the first fastening portion and the second fastening portion.

13. The work apparatus according to claim 11 ,
wherein the holding element has a slot-like receptacle into which a fastening rib of the motor unit projects.

14. The work apparatus according to claim 13 ,
wherein the fastening rib has a roof which engages at least partially over the holding element.

15. The work apparatus according to claim 13 ,
wherein the predetermined breaking point is formed by a notch, wherein the receptacle is bounded by the fastening portion, wherein the notch extends from that side of the fastening portion that faces the receptacle into the holding element.

16. The work apparatus according to claim 13 ,
wherein the receptacle is bounded on the side opposite the first fastening portion by a lateral rib, wherein the lateral rib has an opening through which a fastening element projects, wherein the lateral rib has a first region facing the second fastening portion and a second region facing away from the second fastening portion, and wherein the second region of the lateral rib is offset with respect to the first region on the side facing away from the first fastening portion.

17. The work apparatus according to claim 1 ,
wherein the antivibration element comprises a helical spring, and wherein a longitudinal center axis of the antivibration element is a longitudinal center axis of the helical spring.

18. The work apparatus according to claim 17 ,
wherein the holding element comprises a first fastening portion for fastening to the motor unit and a second fastening portion for fastening to a damping element of the antivibration element, and wherein the second fastening portion is a threaded portion which bears an external thread and has been screwed into the helical spring.

Assignees

• Stihl Ag & Co Kg Andreas

Inventors

• Kurzenberger Jan
• Knauβ Jens
• Menzel Johannes
• Friedrich Sebastian

Classifications

• B25F5/006 Primary

  Vibration damping means · CPC title

• B23Q11/0032

  Arrangements for preventing or isolating vibrations in parts of the machine (B23B29/022, B23D47/005 take precedence; means for damping or suppressing vibrations, in general F16F) · CPC title

• B27B17/0033

  Devices for attenuation of vibrations · CPC title

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title