Power tool

• US 8,418,780 B2
• Filed: 12/04/2008
• Issued: 04/16/2013
• Est. Priority Date: 12/07/2007
• Status: Active Grant

• Current Assignee: Johnson Electric International AG (Johnson Electric Holdings Limited)
• Original Assignee: Johnson Electric SA 125 Rue de Progres La Chaux de Fonds Switzerland (Johnson Electric Holdings Limited)
• Inventors: Lau, James Ching Sik, Louie, Yuen Tung
• Primary Examiner(s): Elve, M. Alexandra
• Assistant Examiner(s): CHUKWURAH, NATHANIEL C
• Application Number:
  US12/328,326
• Publication Number:
  US 20090145621A1
• Time in Patent Office: 1,594 Days
• Field of Search: 173/171, 173/217, 310/60.R, 310/64, 429/61, 429/71, 429/120
• US Class Current: 173/171
• CPC Class Codes: B25F 5/008 Cooling means

Abstract

A power tool having a cooling system, comprises: a motor housing 11 having a main chamber 14 accommodating a tool motor 12; a handle 15 for holding the power tool and having a cooling passage 16 for the transfer of cooling fluid, at least one inlet 18 leading to the cooling passage and at least one outlet 13 leading away from the cooling passage 18 , and a power tool component 21 which generates heat disposed in thermal contact with the cooling passage 16 between the inlet 18 and the outlet 13.

Claims

1. A power tool having a cooling system, comprising:

a motor housing having a main chamber,

a tool motor accommodated within the main chamber,

a handle for holding the power tool, the handle having a dedicated cooling passage separate from a remainder of the handle for the transfer of cooling fluid, an inlet leading to the cooling passage and an outlet leading away from the cooling passage, and

a control device for controlling operation of the tool motor, which generates heat, disposed inside the handle, in thermal contact with the cooling passage between the inlet and the outlet,

wherein the cooling passage comprises a cooling conduit of high heat transfer material and wherein a heat sink of the power tool component is directly attached to the cooling conduit.

2. A power tool having a cooling system, comprising:

a motor housing having a main chamber,

a tool motor accommodated within the main chamber,

a handle for holding the power tool, the handle having a dedicated cooling passage separate from a remainder of the handle for the transfer of cooling fluid, an inlet leading to the cooling passage and an outlet leading away from the cooling passage, and

a control device for controlling operation of the tool motor, which generates heat, disposed inside the handle, in thermal contact with the cooling passage between the inlet and the outlet.

3. The power tool of claim 2, including a flow induction device for inducing flow of cooling fluid from the inlet to the outlet.

4. The power tool of claim 3, wherein the flow induction device is located at least partially in the main chamber of the cooling passage.

5. The power tool of claim 3, wherein the flow induction device comprises one or more fans.

6. The power tool of claim 3, wherein the flow induction device is a fan driven by the tool motor.

7. The power tool of claim 3 , wherein the control device includes a speed control circuitry.

8. The power tool of claim 7, further comprising a heat sink, for the speed control circuitry, located at least partially in the cooling passage.

9. The power tool of claim 8, wherein the flow induction device is a fan mounted on the heat sink.

10. The power tool of claim 2, further comprising a battery casing having one or more of said inlets and accommodating a number of batteries, wherein the handle extends between the main chamber and the battery casing.

11. The power tool of claim 2, wherein a heat pipe is disposed in the cooling passage, the heat pipe being in direct contact with a heat sink of the control device.

12. The power tool of claim 2, wherein the cooling passage comprises a rubber tube and further includes a heat transfer box connected to the rubber tube and at least partially housing a cooling portion of the control device.

13. The power tool of claim 12, wherein the cooling portion of the control device comprises fins of a heat sink.

14. The power tool of claim 2, wherein the control device includes a switch.

15. A power tool having a cooling system, comprising:

a motor housing having a main chamber,

a tool motor accommodated within the main chamber,

a handle for holding the power tool,

a heat pipe accommodated inside the handle, and separate from a remainder of the handle

a control device for controlling operation of the tool motor which generates heat, disposed inside the handle, wherein the control device is in thermal contact with the heat pipe.

16. The power tool of claim 15, wherein the heat pipe is cooled by a flow of cooling air within the main chamber.

17. The power tool of claim 15, wherein the heat pipe makes thermal contact with a heat sink of a battery attached to the handle.