Active cooling for power tool gripping surfaces

• US 9,919,411 B2
• Filed: 12/08/2015
• Issued: 03/20/2018
• Est. Priority Date: 12/08/2015
• Status: Active Grant

• Current Assignee: Nanjing Chervon Industry Company Limited (Chervon Holdings Limited)
• Original Assignee: Nanjing Chervon Industry Company Limited (Chervon Holdings Limited)
• Inventors: McAuliffe, Patrick M., Amrol, Jr., Roger N.
• Primary Examiner(s): PAYER, HWEI-SIU C
• Application Number:
  US14/962,452
• Publication Number:
  US 20170157760A1
• Time in Patent Office: 833 Days
• CPC Class Codes: B23D 49/16 actuated by electric or magnetic power or prime movers B23D49/11 takes precedence
• 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

Abstract

A power tool includes a housing having a front portion and a handle portion. The front portion defines a cavity that encloses a motor and includes a gripping portion surrounding the cavity. An insulating cover is provided on the gripping portion of the housing and includes a gripping surface. A thermoelectric cooling unit is located between the gripping portion of the housing and the insulating cover. The thermoelectric cooling unit has a cold side positioned in thermal contact with an inner surface of the insulating cover and a hot side positioned in contact with an outer surface of the gripping portion of the housing. The thermoelectric cooling unit is configured to absorb thermal energy from the insulating cover via the cold side of the thermoelectric cooling unit and to release the absorbed heat via the hot side of the thermoelectric cooling unit.

Claims

1. A power tool comprising:

a housing having a front portion and a handle portion, the front portion defining a cavity that encloses a motor and including a gripping portion surrounding the cavity, the handle portion including a switch configured to control power to the motor;

a drive assembly coupled to the motor and including a tool holder located externally with respect to the housing, the drive assembly being configured to impart a drive motion to the tool holder in response to being driven by the motor, the tool holder being configured to retain a working tool for performing work when the tool holder is driven to move by the drive assembly;

an insulating cover provided on the gripping portion of the housing, the insulating cover including a gripping surface; and

a thermoelectric cooling unit located between the gripping portion of the housing and the insulating cover, the thermoelectric cooling unit comprising a pair of thermally conductive plates having two dissimilar semi-conductors arranged therebetween and a first one of the pair of thermally conductive plates defining a cold side positioned in thermal contact with an inner surface of the insulating cover and a second one of the pair of thermally conductive plates defining a hot side positioned in thermal contact with the gripping portion of the housing,

wherein the thermoelectric cooling unit is configured to absorb thermal energy from the insulating cover via the cold side of the thermoelectric cooling unit and to release the absorbed thermal energy via the hot side of the thermoelectric cooling unit.

2. The power tool of claim 1, wherein the thermoelectric cooling unit is configured to receive an electric current for powering the thermoelectric cooling unit from an electrical system of the power tool.

3. The power tool of claim 1, further comprising a heat sink coupled to the thermoelectric cooling unit for releasing heat from the hot side of the thermoelectric cooling unit.

4. The power tool of claim 3, wherein the heat sink is positioned in an air flow channel defined in the housing for directing a flow of air generated by a fan on the motor.

5. The power tool of claim 4, further comprising at least one heat pipe that transports heat from the hot side of the thermoelectric cooling unit to the heat sink.

6. The power tool of claim 1, wherein the insulating cover is formed of a rubber material.

7. The power tool of claim 6, wherein the thermoelectric cooling unit is embedded into the insulating cover.

8. The power tool of claim 1, wherein a first one of the dissimilar semi-conductors is an n-type conductive element and wherein a second one of the dissimilar semi-conductors is a p-type conductive element.

9. The power tool of claim 8, wherein the n-type conductive element and the p-type conductive element are connected electrically in series and thermally in parallel.

10. The power tool of claim 1, wherein each of the pair of thermally conductive plates is a ceramic plate.

11. A reciprocating saw comprising:

a housing having a front portion and a handle portion, the front portion defining a cavity that encloses a motor and including a gripping portion surrounding the cavity, the handle portion including a switch configured to control power to the motor;

a reciprocating drive assembly coupled to the motor and including a tool holder located externally with respect to the housing, the drive assembly being configured to impart a reciprocating drive motion to the tool holder in response to being driven by the motor, the tool holder being configured to retain a working tool for performing work when the tool holder is driven to move by the reciprocating drive assembly;

an insulating cover provided on the gripping portion of the housing, the insulating cover including a gripping surface; and

a thermoelectric cooling unit located between the gripping portion of the housing and the insulating cover, the thermoelectric cooling unit comprising a pair of thermally conductive plates having two dissimilar semi-conductors arranged therebetween and a first one of the pair of thermally conductive plates defining a cold side positioned in thermal contact with an inner surface of the insulating cover and a second one of the pair of thermally conductive plates defining a hot side positioned in contact with an outer surface of the gripping portion of the housing,

wherein the thermoelectric cooling unit is configured to absorb thermal energy from the insulating cover via the cold side of the thermoelectric cooling unit and to release the absorbed thermal energy via the hot side of the thermoelectric cooling unit.

12. The reciprocating saw of claim 11, wherein the thermoelectric cooling unit is configured to receive an electric current for powering the thermoelectric cooling unit from an electrical system of the reciprocating saw.

13. The reciprocating saw of claim 11, further comprising a heat sink coupled to the hot side of the thermoelectric cooling unit for releasing heat from the hot side of the thermoelectric cooling unit.

14. The reciprocating saw of claim 13, wherein the heat sink is positioned in an air flow channel defined in the housing for directing a flow of air generated by a fan on the motor.

15. The reciprocating saw of claim 14, further comprising at least one heat pipe that transports heat from the hot side of the thermoelectric cooling unit to the heat sink.

16. The reciprocating saw of claim 11, wherein the insulating cover is formed of a rubber material.

17. The reciprocating saw claim 16, wherein the thermoelectric cooling unit is embedded into the insulating cover.