Carburetor for a hand-guided power tool and hand-guided power tool

Patent metadata

Field	Value
Publication number	US-9650950-B2
Application number	US-201314108383-A
Country	US
Kind code	B2
Filing date	Dec 17, 2013
Priority date	Dec 22, 2012
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A carburetor for a hand-guided power tool has a carburetor housing and a carburetor rotor supported rotatably in the carburetor housing about an axis of rotation. A needle is disposed on the carburetor rotor and projects into a fuel opening of the carburetor. An adjusting element is operatively connected to the needle so as adjust a position of the needle relative to the carburetor rotor. The adjusting element has an engagement contour that is to be engaged by a tool for adjusting the adjusting element. A securing contour that is fixedly connected to the carburetor rotor is provided. The securing contour, at any point of the securing contour, has a spacing to the axis of rotation of at least approximately 10 mm.

First claim

What is claimed is:

1. A carburetor for a hand-guided power tool, the carburetor comprising:
a carburetor housing;
a carburetor rotor supported rotatably in the carburetor housing about an axis of rotation;
a needle disposed on the carburetor rotor and projecting into a fuel opening of the carburetor;
an adjusting element operatively connected to the needle so as adjust a position of the needle relative to the carburetor rotor, wherein the adjusting element is rotatable relative to the carburetor rotor for adjusting the position of the needle;
the adjusting element having an engagement contour adapted to be engaged by a tool for adjusting the adjusting element;
a securing contour, configured to secure the carburetor rotor against rotation about the axis of rotation, the securing contour fixedly connected to the carburetor rotor;
the securing contour, in a plan view of the securing contour in the direction of the axis of rotation, at any point of the securing contour, having a spacing relative to the axis of rotation of less than approximately 10 mm;
wherein the securing contour enables a fixation of the carburetor rotor against rotation about the axis of rotation so that the adjusting element can be rotated relative to the securing contour and an adjustment of the position of the needle by rotating the adjusting element relative to the carburetor rotor is possible without the carburetor rotor being rotated.

2. The carburetor according to claim 1 , wherein the engagement contour is arranged in a recess which is delimited by a circumferential wall.

3. The carburetor according to claim 2 , wherein the securing contour is arranged on the circumferential wall.

4. The carburetor according to claim 3 , wherein the securing contour is arranged on an end face of the circumferential wall.

5. The carburetor according to claim 2 , wherein an outer diameter of the circumferential wall at the securing contour is less than approximately 15 mm.

6. The carburetor according to claim 2 , wherein an exterior side of the circumferential wall facing away from the recess has a locking element that is a component of a starter device.

7. The carburetor according to claim 2 , wherein the circumferential wall has a circular ring-shaped cross-section.

8. The carburetor according to claim 2 , wherein the spacing between the circumferential wall and the engagement contour is at most approximately 2.5 mm.

9. The carburetor according to claim 1 , wherein the securing contour has at least one tooth.

10. The carburetor according to claim 1 , wherein the securing contour has at least one first flank which is positioned at an angle of less than approximately 10° relative to the axis of rotation of the carburetor rotor.

11. The carburetor according to claim 10 , wherein the first flank is oriented opposite to a rotational direction of the carburetor rotor for a rotation from an idle position to a full throttle position.

12. The carburetor according to claim 10 , wherein the securing contour has at least one second flank that is positioned at an angle of approximately 20° to approximately 70° relative to the axis of rotation of the carburetor rotor.

13. The carburetor according to claim 1 , wherein the engagement contour has a three-dimensional configuration and the tool has a three-dimensional configuration matched to the three-dimensional configuration of the engagement contour.

14. A hand-guided power tool comprising:
a power tool housing;
a carburetor arranged in the power tool housing and supplying fuel and combustion air to an internal combustion engine of the power tool;
the carburetor having a carburetor housing and a carburetor rotor rotatably supported about an axis of rotation in the carburetor housing;
the carburetor further having a needle disposed on the carburetor rotor and projecting into a fuel opening of the carburetor;
the carburetor further having an adjusting element operatively connected to the needle so as adjust a position of the needle relative to the carburetor rotor, wherein the adjusting element is rotatable relative to the carburetor rotor for adjusting the position of the needle, wherein the adjusting element has an engagement contour adapted to be engaged by a tool for adjusting the adjusting element;
the carburetor further having a securing contour, configured to secure the carburetor rotor against rotation about the axis of rotation, the securing contour fixedly connected to the carburetor rotor, wherein the securing contour, in a plan view of the securing contour in the direction of the axis of rotation, at any point of the securing contour, has a spacing relative to the axis of rotation of less than approximately 10 mm;
wherein the securing contour enables a fixation of the carburetor rotor against rotation about the axis of rotation so that the adjusting element can be rotated relative to the securing contour and an adjustment of the position of the needle by rotating the adjusting element relative to the carburetor rotor is possible without the carburetor rotor being rotated.

15. The power tool according to claim 14 , wherein the power tool housing has a housing opening through which the securing contour is accessible, wherein between the securing contour and the housing opening a slot is formed.

16. The power tool according to claim 14 , wherein a width of the slot is measured in a plane extending perpendicularly to the axis of rotation of the carburetor rotor, wherein a greatest width of the slot is less than approximately 7 mm.

17. The power tool according to claim 14 , wherein a width of the slot is measured in a plane extending perpendicularly to the axis of rotation of the carburetor rotor, wherein a greatest width of the slot is smaller than a diameter of the engagement contour.

18. The power tool according to claim 14 , wherein the slot is designed such that a round rod with a diameter of 7 mm cannot be inserted into the slot.

Assignees

• Stihl Ag & Co Kg Andreas

Inventors

• Oppenländer Kai
• Fattorusso Antonio
• Amann Jörg
• Götzel Arne

Classifications

• F02B2075/025

  two · CPC title

• F02M9/085

  Fuel spray nozzles in the throttling valves · CPC title

• F02M23/03

  the secondary air-valve controlled by main combustion-air throttle · CPC title

• F02B63/02 Primary

  for hand-held tools · CPC title

• F02M1/16

  Other means for enriching fuel-air mixture during starting; Priming cups; using different fuels for starting and normal operation · CPC title