Battery Pack-Operated Hand-Guided Power Tool with Throttle Lever

• US 20100218966A1
• Filed: 02/22/2010
• Published: 09/02/2010
• Est. Priority Date: 02/27/2009
• 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: Hamersmit, Ante, Liebhard, Gernot
• Granted Patent: US 8,353,362 B2
• Time in Patent Office: Days
• US Class Current: 173/170
• CPC Class Codes: A01G 3/053 motor-driven
• CPC Class Codes: B25F 5/001 Gearings, speed selectors, clutches or the like specially adapted for rotary tools
• CPC Class Codes: H01H 2300/026 Application dead man switch: power must be interrupted on release of operating member

Abstract

A hand-held power tool has a device housing and at least one grip disposed on the device housing. An electric drive motor is arranged in the device housing for operating a working tool. A battery pack provides electric energy for operating the electric drive motor. An electronic control unit is connected to the electric drive motor and the battery pack. An operating element disposed on the grip controls the electric drive motor. An electric actuator is acted upon by the operating element and the output signal of the electric actuator is supplied to the electronic control unit. Electric energy is applied to the electric drive motor by the electronic control unit as a function of a position of the operating element, wherein in a first dead travel range of the operating element that adjoins an inoperative position of the operating element the supplied electric energy is zero.

Claims

1. A hand-held power tool comprising:

a device housing;

at least one grip disposed on said device housing;

an electric drive motor arranged in said device housing;

an output connected to said electric motor for operating a working tool;

a battery pack providing electric energy for operating said electric drive motor;

an electronic control unit connected to said electric drive motor and said battery pack;

an operating element disposed on said at least one grip for controlling said electric drive motor;

an electric actuator acted upon by said operating element, wherein an output signal of said electric actuator is supplied to said electronic control unit;

wherein an electric energy is applied to said electric drive motor by said electronic control unit as a function of a position of said operating element, wherein in a first dead travel range of said operating element that adjoins an inoperative position of said operating element the supplied electric energy is zero.

2. The power tool according to claim 1, wherein said first dead travel range of said operating element is approximately 30% to 60% of a total travel range.

3. The power tool according to claim 2, wherein said first dead travel range of said operating element is approximately 40% to 45% of said total travel range.

4. The power tool according to claim 1, wherein said operating element is pivotable about an axis of rotation and wherein said first dead travel range corresponds to a rotary angle of 0°

to 10°

.

5. The power tool according to claim 4, wherein said first dead travel range corresponds to a rotary angle of up to 7°

.

6. The power tool according to claim 1, wherein upon passing from said first dead travel range to an adjoining second travel range the electric energy jumps from zero to a predetermined electric energy value.

7. The power tool according to claim 6, wherein the predetermined electric energy value is approximately 30% of a nominal power of said electric drive motor.

8. The power tool according to claim 1, wherein a control signal of said electronic control unit supplied to said electric drive motor is a pulse width-modulated signal sequence.

9. The power tool according to claim 8, wherein said pulse width-modulated signal sequence is a direct current signal.

10. The power tool according to claim 1, wherein said electric drive motor is an electronically commutated motor.

11. The power tool according to claim 10, wherein control electronics of said electronically commutated motor are integrated into said electronic control unit.

12. The power tool according to claim 1, comprising a switch arranged on said at least one grip, wherein said switch is a component of a two-hand safety device.

13. The power tool according to claim 1, wherein said electronic control unit comprise a power circuit that supplies operating power, wherein said power circuit comprises at least one mechanical switch.

14. The power tool according to claim 13, wherein said electronic control unit and a switching position of said at least one mechanical switch are matched to one another such that said at least one mechanical switch opens and/or closes when currentless.