Battery operated handheld power tool

• US 9,770,821 B2
• Filed: 10/06/2011
• Issued: 09/26/2017
• Est. Priority Date: 10/06/2011
• Status: Active Grant

• Current Assignee: Husqvarna AB (HUSQVARNA)
• Original Assignee: Husqvarna AB (HUSQVARNA)
• Inventors: Racov, Mikael, Svennung, Johan, Arvidsson, Mikael
• Primary Examiner(s): Smith, Scott A.
• Application Number:
  US14/349,781
• Publication Number:
  US 20140246214A1
• Time in Patent Office: 2,182 Days
• Field of Search: 173217, 173117, 173170, 173213, 173171, 310 47, 310 50, 310 58, 310 36, 320107, 320150, 318276, 318246, 318268, 318446, 318490, 30276, 30122, 30208, 30210, 302961, 30340, 30517
• CPC Class Codes: A01D 34/4163 by triggered line feedout, e.g. bump-feeding
• CPC Class Codes: A01D 34/902 Ergonomic provisions
• CPC Class Codes: A01D 69/02 electric
• CPC Class Codes: B25F 5/008 Cooling means
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: H02K 5/207 with openings in the casing specially adapted for ambient air
• CPC Class Codes: H02K 9/06 with fans or impellers driven by the machine shaft
• CPC Class Codes: H05K 7/20 Modifications to facilitate cooling, ventilating, or heating

Abstract

A battery operated handheld power tool, the power tool (1) comprising a working tool assembly (20), comprising a working tool of the power tool and an electric motor, arranged to drive the working tool, a handle assembly (10), comprising a body portion (11) to which a battery pack (13) may be detachably connected, which battery pack (13) is arranged to provide electric power to the electric motor, a control unit (15), provided in the body portion (16) so as to control a flow of electric current from the battery pack (13) to the motor. The battery operated handheld power tool is characterized in that the body portion (11) comprises a fan (14), arranged to generate a flow of air passing by the control unit (15) during operation of the power tool (1).

Claims

1. A battery operated handheld power tool, the power tool comprising:

a working tool assembly comprising a working tool of the power tool and an electric motor, arranged to drive the working tool,

a handle assembly comprising a body portion to which a battery pack is detachably connected, the battery pack being arranged to provide electric power to the electric motor, wherein the battery is received in a through hole extending completely through the body portion,

a control unit provided in the body portion to control a flow of electric current from the battery pack to the electric motor, and

a fan disposed in the body portion and separate from the electric motor, wherein the fan is arranged to generate a flow of air around the through hole within the body portion to pass by the control unit during operation of the power tool.

2. The battery operated handheld power tool according to claim 1, wherein the fan is controlled by the control unit.

3. The battery operated handheld power tool according to claim 2, wherein the control unit activates the fan based on a temperature of the control unit.

4. The battery operated handheld power tool of claim 3 further comprising a temperature sensor provided on the control unit to sense the temperature of the control unit.

5. The battery operated handheld power tool according to claim 1, wherein the control unit is arranged in a control unit housing made from metal.

6. The battery operated handheld power tool according to claim 5 wherein the control unit housing is made from aluminum.

7. The battery operated handheld power tool according to claim 1, wherein the fan is arranged to suck ambient air from an air inlet provided in a cover of the body portion and to direct the air flow towards the control unit and further to an air outlet provided in the cover.

8. The battery operated handheld power tool of claim 1, wherein the body portion is disposed at a proximal end of the handle assembly and the working tool assembly is disposed at a distal end of the handle assembly.

9. The battery operated handheld power tool of claim 1, wherein the body portion comprises a cover, wherein the cover comprises air inlets and air outlets.

10. The battery operated handheld power tool of claim 1, wherein the battery operated handheld power tool comprises a grass trimmer.

11. The battery operated handheld power tool of claim 1, wherein the battery is received in the through hole in a direction perpendicular to a direction of longitudinal extension of the battery operated handheld power tool.

12. The battery operated handheld power tool of claim 1, wherein the body portion comprises a cover including an outer wall and an inner wall, wherein the inner wall is defined by the through hole and the flow of air passes between the outer wall and the inner wall.

13. The battery operated handheld power tool of claim 12, wherein the outer wall comprises an air inlet and an air outlet disposed at opposite sides of the control unit.

14. The battery operated handheld power tool of claim 13, wherein the air inlet is disposed at a first end of the outer wall and the air outlet is disposed at a second end of the outer wall opposite the first end.

15. The battery operated handheld power tool of claim 13, wherein, in a working position, the air inlet are disposed in a rearward and upward facing portion of the outer wall of the cover and the air outlet are disposed in a forward and downward facing portion of the outer wall of the cover.