Implement having speed regulation

• US 6,494,180 B1
• Filed: 09/01/2000
• Issued: 12/17/2002
• Est. Priority Date: 09/03/1999
• Status: Expired due to Fees

• Current Assignee: Andreas STIHL AG & Company KG (Stihl Holding AG & Company KG)
• Original Assignee: Andreas STIHL AG & Company KG (Stihl Holding AG & Company KG)
• Inventors: Schlossarczyk, Jörg
• Primary Examiner(s): Dolinar, Andrew M.
• Application Number:
  US09/654,422
• Time in Patent Office: 837 Days
• Field of Search: 123/392, 123/437, 261/35, 261/69.2, 261/DIG.68
• US Class Current: 123/392
• CPC Class Codes: F01P 5/02 Pumping cooling-air; Arrangements of cooling-air pumps, e.g. fans or blowers
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02B 2075/027 four
• CPC Class Codes: F02B 63/02 for hand-held tools
• CPC Class Codes: F02D 2009/0216 of the air-vane type
• CPC Class Codes: F02D 31/009 for maximum speed control
• CPC Class Codes: F02M 17/04 having fuel inlet valve controlled by diaphragm
• CPC Class Codes: Y10S 261/68 Diaphragm-controlled inlet valve

Abstract

A manually guided implement having an internal combustion engine is provided. A fuel/air mixture is supplied to the internal combustion engine via a diaphragm carburetor. The engine is cooled by a cooling fan that is driven by the internal combustion engine and that generates an air stream. The diaphragm carburetor has a fuel-filled control chamber with a control diaphragm which on that side facing away from the control chamber delimits a compensation chamber. To limit speed, a control pressure line is provided between the compensation chamber and the air stream generated by the cooling fan.

Claims

1. A manually guided implement having an internal combustion engine, comprising:

a diaphragm carburetor for supplying a fuel/air mixture to the internal combustion engine, wherein the diaphragm carburetor has a fuel-filled control chamber, a compensation chamber, and a control diaphragm that separates the control chamber and the compensation chamber;

a cooling fan that is driven by said internal combustion engine and generates an air stream, wherein said cooling fan is embodied as a radial fan having a fan wheel with a fan disk that rotates about a vertical fan axis and is provided on one side with cooling air blades;

a control pressure line for establishing communication, in an air pressure transmitting manner, between a region of said air stream and said compensation chamber of said diaphragm carburetor, wherein said control pressure line branches off from a side of said fan disk that is remote from said cooling air blades;

an air cleaning mechanism provided in said air stream, wherein an air stream end of said control pressure line is provided with a pressure-obtaining opening that is disposed on a clean air side of said air cleaning mechanism; and

further blades provided on a backside of said fan disk that faces away form said cooling air blades, wherein said pressure-obtaining opening is disposed between said fan axis and an inner radius of said further blades.

2. An implement according to claim 1, wherein said pressure-obtaining opening is disposed close to said inner radius.

3. An implement according to claim 1, wherein said air stream end of said control pressure line is embodied as a pilot tube, and wherein said pressure-obtaining opening is disposed so as to face said air stream.

4. An implement according to claim 3, wherein a portion of said control pressure line is embodied as a flexible hose.

5. A manually guided implement having an internal combustion engine, comprising:

a diaphragm carburetor for supplying a fuel/air mixture to the internal combustion engine, wherein the diaphragm carburetor has a fuel-filled control chamber, a compensation chamber, and a control diaphragm that separates the control chamber and the compensation chamber;

a cooling fan that is driven by said internal combustion engine and generates an air stream;

a control pressure line for establishing communication, in an air pressure transmitting manner, between a region of said air stream and said compensation chamber of said diaphragm carburetor; and

an air cleaning mechanism provided in said air stream, wherein an air stream end of said control pressure line is provided with a pressure-obtaining opening that is disposed on a clean air side of said air cleaning mechanism, wherein said air stream end of said control pressure line is embodied as a pitot tube, wherein said pressure-obtaining opening is disposed so as to face said air stream and, wherein static pressure openings are provided on a periphery of said pitot tube.

6. An implement according to claim 5, wherein said cooling fan is embodied as a radial fan having a fan wheel with a fan disk that rotates about a vertical fan axis and is provided on one side with cooling air blades, and wherein said control pressure line branches off from a side of said fan disk that is remote from said cooling air blades.

7. An implement according to claim 6, wherein said pressure-obtaining opening of said control pressure line is disposed in said air stream at a radial distance relative to said fan axis.

8. An implement according to claim 6, wherein said pressure-obtaining opening is disposed on said side of said fan disk that is remote from said cooling air blades.

9. A manually guided implement having an internal combustion engine, comprising:

a diaphragm carburetor for supplying a fuel/air-mixture to the internal combustion engine, wherein the diaphragm carburetor has a fuel-filled control chamber, a compensation chamber, and a control diaphragm that separates the control chamber and the compensation chamber;

a cooling fan that is driven by said internal combustion engine and generates an air stream, wherein said cooling fan is disposed in a fan housing;

a control pressure line for establishing communication in an air pressure transmitting manner, between a region of said air stream and said compensation chamber of said diaphragm carburetor; and

an air cleaning mechanism provided in said air stream, wherein an air stream end of said control pressure line is provided with a pressure-obtaining opening that is disposed on a clean air side of said air cleaning mechanism, wherein said air in stream end of said control pressure line is embodied as a pitot tube, wherein said pressure-obtaining opening is disposed so as to face said air stream, and wherein said pitot tube is monolithically formed with said fan housing.

10. A manually guided implement having an internal combustion engine, comprising:

a diaphragm carburetor for supplying a fuel/air mixture to the internal combustion engine, wherein the diaphragm carburetor has a fuel-filled control chamber, a compensation chamber, and a control diaphragm that separates the control chamber and the compensation chamber;

a cooling fan that is driven by said internal combustion engine and generates an air stream;

a control pressure line for establishing communication, in an air pressure transmitting manner, between a region of said air stream and said compensation chamber of said diaphragm carburetor; and

an intake air filter for air for combustion, wherein a clean air side of said intake air filter is connected in a pressure transmitting manner via a balancing restrictor with said compensation chamber of said diaphragm carburetor.

11. An implement according to claim 10, wherein an air cleaning mechanism is provided in said air stream, and wherein an air stream end of said control pressure line is provided with a pressure-obtaining opening that is disposed on a clean air side of said air cleaning mechanism.