Handheld work apparatus with switchable power

• US 9,010,454 B2
• Filed: 12/06/2011
• Issued: 04/21/2015
• Est. Priority Date: 12/06/2010
• Status: Active Grant

• 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: Neubauer, Andreas, Gegg, Tim
• Primary Examiner(s): Smith, Scott A.
• Application Number:
  US13/312,713
• Publication Number:
  US 20120138322A1
• Time in Patent Office: 1,232 Days
• Field of Search: 173/2, 173/4, 173/176, 173/181, 173/217, 173/47, 814/69, 834/772, 318/362, 318/375, 318/757, 340/426.1, 340/572.1, 340/573.1
• US Class Current: 173/2
• CPC Class Codes: A01D 34/90 for carrying by the operator
• CPC Class Codes: B23D 59/001 Measuring or control devices, e.g. for automatic control of work feed pressure on band saw blade measuring in general G01; controlling in general G05
• CPC Class Codes: B24B 23/00 Portable grinding machines, e.g. hand-guided; Accessories therefor B24B7/18 takes precedence; for grinding seat surfaces B24B15/00; having a flexible shaft B24B27/027; grinders for cutting-off B24B27/08; dust extraction equipment B24B55/10; details or components, e.g. casings, bodies of portable power-driven tools not particularly related to the operation performed B25F5/00
• CPC Class Codes: B24B 27/0691 for controlling the feeding or return movement of the saw
• CPC Class Codes: B24B 27/08 being portable
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: B26D 1/25 with a non-circular cutting member
• CPC Class Codes: B26D 5/00 Arrangements for operating and controlling machines or devices for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
• CPC Class Codes: Y10T 83/773 Work-support includes passageway for tool [e.g., slotted table]

Abstract

The invention relates to a portable, handheld work apparatus such as a trimmer, a cut-off machine, a chain saw or the like, having a motor (5, 33) to drive a rotating, exchangeable work tool (13). A control unit (15) serves to control the operation of the motor (5, 33). The control unit (15) determines the rotational speed (n) and/or the power (P) of the motor (5, 33). According to the invention, the motor (5, 33) can be operated in a first operating mode (I) with reduced rotational speed (n₀) and/or power (P₀) and in at least a second operating mode (II) with an increased rotational speed (n₁) and/or power (P₁). In dependence on a release signal, the control uses exclusively the first operating mode (I) for a limited operation and the second operating mode (II) for an expanded operation.

Claims

1. A handheld work apparatus comprising:

a motor configured to drive an exchangeable rotating work tool having a clamping area;

a control unit configured to control the operation of said motor in a first operating mode (I) and a second operating mode (II);

said control unit being configured to operate said motor in said first operating mode (I) having at least one of a rotational speed (n₀) and power (P₀) reduced compared to said second operating mode (II);

said second operating mode (II) including the entire power range (P₁) and rotational speed range (n₁);

a detecting unit connected to said control unit and having a read unit configured to read an identifier of said work tool mounted on said work apparatus;

said detecting unit being configured to evaluate the identifier and form a release signal in dependence upon the evaluation of said identifier;

said control unit being configured to set one of said first operating mode (I) and said second operating mode (II) in dependence upon said release signal;

said read unit being an RFID-transmitter-and-receiver unit and non-rotatably mounted on said work apparatus;

an RFID-tag containing data and being carried by said work tool so as to rotate therewith; and

,

said RFID-tag being mounted within said clamping area so as to place said RFID-tag at a location permitting said RFID-tag to wirelessly transfer said data thereof to said read unit during rotation of said RFID-tag relative to said read unit.

2. The work apparatus of claim 1, wherein:

said detecting unit is configured to compare the detected identifier to a predetermined identifier;

said detecting unit forms said release signal on the basis of the comparison; and

,

said control unit selects one of said operating mode I and said operating mode II on the basis of the comparison.

3. The work apparatus of claim 1 further comprising a memory component having an identifier stored thereon.

4. The work apparatus of claim 3, wherein said memory component is part of said detecting unit.

5. The work apparatus of claim 1, wherein said control unit has only said two operating modes (I, II) and switches between said two operating modes (I, II).

6. The work apparatus of claim 1, wherein said work apparatus is a portable hand-guided work apparatus.

7. The work apparatus of claim 6, wherein said portable hand-guided work apparatus is selected from the group consisting of a motor-driven chain saw, a cut-off machine and a brushcutter.

8. A work apparatus comprising:

a motor configured to drive an exchangeable rotating work tool having a clamping area;

a control unit configured to control the operation of said motor in a first operating mode (I) and a second operating mode (II);

said control unit being configured to operate said motor in said first operating mode (I) having at least one of a rotational speed (n₀) and power (P₀) reduced compared to said second operating mode (II);

said second operating mode (II) including the entire power range (P₁) and rotational speed range (n₁);

a detecting unit connected to said control unit and having a read unit configured to read an identifier on said work tool mounted on said work apparatus;

said detecting unit being configured to evaluate the identifier and form a release signal in dependence upon the evaluation of said identifier;

said control unit being configured to set one of said first operating mode (I) and said second operating mode (II) in dependence upon said release signal with said work apparatus being switched to a safe mode when no release signal is present; and

,

said safe mode is said first operating mode (I) having said at least one of said rotational speed (n₀) and said power (P₀) reduced compared to said second operating mode (II).

9. The work apparatus of claim 8, wherein said detecting unit is configured to compare said identifier read by said read unit to a pregiven identifier and to form said release signal in dependence upon the comparison and to select one of said first and second operating modes (I, II).

10. The work apparatus of claim 8, further comprising a memory component wherein a pregiven identifier is stored.

11. The work apparatus of claim 10, wherein said memory component is part of said detecting unit.

12. The work apparatus of claim 8, wherein said read unit is an RFID-transmitter-and-receiver unit and said work tool carries an RFID-tag.

13. The work apparatus of claim 8, wherein said control unit has only said first and second operating modes (I, II) and switches therebetween.

14. The work apparatus of claim 8, wherein said work apparatus is a portable handheld work apparatus.

15. The work apparatus of claim 14, wherein said portable handheld work apparatus is a work apparatus selected from the group comprising a motor-driven chainsaw, cutoff machine and a brushcutter.

16. The work apparatus of claim 8, further comprising an internal combustion engine to drive said work tool;

and, a vibration sensor; and

, said control unit being configured to operate said engine only in said first operating mode (I) when a predetermined vibration threshold value is exceeded.