Handheld Work Apparatus with Switchable Power

• US 20120138322A1
• Filed: 12/06/2011
• Published: 06/07/2012
• 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
• Granted Patent: US 9,010,454 B2
• Time in Patent Office: Days
• 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 work tool;

a control unit configured to control the operation of said motor;

said control unit being configured to operate said motor in a first operating mode (I) having at least one of a reduced rotational speed (n₀) and reduced power (P₀) and in a second operating mode (II) having at least one of an increased rotational speed (n₁) and an increased power (P₁);

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; and

,

said control unit being configured to set one of said operating mode I and said operating mode II in dependence upon said release signal.

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 read unit is a RFID send and receive unit and said work apparatus further comprises an RFID tag mounted on the work tool.

6. The work apparatus of claim 1, wherein said read unit is arranged on said work apparatus in a non-rotatable manner.

7. The work apparatus of claim 6, wherein said work apparatus further comprises an RFID tag and said work tool is a rotating work tool;

said detecting unit is configured to detect said RFID tag; and

, said RFID tag is arranged in a clamping region of said rotating work tool.

8. The work apparatus of claim 1, wherein said control unit has only two operating modes and switches between said two operating modes.

9. The work apparatus of claim 1, wherein said control unit switches to a safe mode when no release signal is present.

10. The work apparatus of claim 9, wherein said safe mode is said first operating mode (I) with at least one of reduced rotational speed (n₀) and reduced power (P₀).

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

12. The work apparatus of claim 11, 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.