Power tools

• US 6,933,689 B2
• Filed: 04/25/2003
• Issued: 08/23/2005
• Est. Priority Date: 04/26/2002
• Status: Active Grant

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Yamamoto, Hirokatsu
• Primary Examiner(s): Martin, David
• Assistant Examiner(s): SMITH, TYRONE W
• Application Number:
  US10/423,226
• Publication Number:
  US 20030201738A1
• Time in Patent Office: 851 Days
• Field of Search: 318/139, 318/430, 318/432, 318/434, 318/254, 318/439, 318/178, 318/181, 173/178, 173/181, 173/217
• US Class Current: 318/139
• CPC Class Codes: B25F 5/02 Construction of casings, bodies or handles B25F5/006, B25F5/008 take precedence
• CPC Class Codes: H01H 9/06 Casing of switch constituted by a handle serving a purpose other than the actuation of the switch, e.g. by the handle of a vacuum cleaner
• CPC Class Codes: H01H 9/22 for interlocking between casing, cover, or protective shutter and mechanism for operating contacts explosion-proof cases H01H9/045; built-in fuses and interlocking mechanisms H01H9/104; by automatic release of circuit breakers H01H71/126

Abstract

It is an object of the invention to provide a technique to effectively prevent a power tool from being adversely affected when a battery is removed from the power tool. According to the present invention, a power tool is provided that includes a tool bit, a motor that drives the tool bit, a body that houses the motor, a battery detachably coupled to the body so as to supply driving current to operate the motor, and a battery removal preventing device. Within the power tool, the battery removal preventing device prevents the battery from being removed from the body during operation of the motor and allows the battery to be removed from the body only when the motor is stopped. As a result, arc can be effectively prevented from being generated between the battery and the body of the power tool.

Claims

1. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor, and

a battery removal preventing device that prevents the battery from being removed from the body during operation of the motor and allows the battery to be removed from the body only when the motor is stopped, said battery removal preventing device automatically engaging when the motor is being driven and automatically disengaging when the motor is no longer driven.

2. The power tool as defined in claim 1, wherein the battery removal preventing device includes a battery lock that detachably locks the battery to the body, the battery lock being adapted to lock the battery to the body when the motor is started and to release the engagement between the battery and the body only when the motor is stopped.

3. The power tool as defined in claim 1, further comprising a trigger switch that is operated to start and stop the motor, wherein the battery removal preventing device includes a battery lock to removably lock the battery to the body and a trigger switch interlocking member that transmits the operational movement of the trigger switch to the battery lock so as to operate the battery lock, the battery lock being adapted to lock the battery to the body via the trigger switch interlocking member when the trigger switch is operated to start the motor and to release the engagement between the battery and the body via the trigger switch interlocking member only when the trigger switch is operated to stop the motor.

4. The power tool as defined in claim 1, wherein the battery removal preventing device includes a battery lock to removably lock the battery to the body and a control device that outputs a lock signal and/or a lock release signal to the battery lock in accordance with the operating state of the motor, the battery lock being adapted to lock the battery to the body based on the lock signal outputted from the control device when the motor is started and to release the engagement between the battery and the body based on the lock release signal outputted from the control device only when the motor is stopped.

5. The power tool as defined in claim 1, further comprising a power circuit that provides driving current from the battery to the motor, a trigger switch that is electrically connected to a control circuit of the power tool independently of the power circuit, the trigger switch being operated to start and stop the motor, wherein the battery removal preventing device includes a battery lock to removably lock the battery to the body and a trigger switch interlocking member that transmits the operational movement of the trigger switch to the battery lock so as to operate the battery lock, the battery lock being adapted to lock the battery to the body via the trigger switch interlocking member when the trigger switch is operated to start the motor and to release the engagement between the battery and the body via the trigger switch interlocking member only when the trigger switch is operated to stop the motor.

6. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

an attaching device that removably attaches the battery to the body and

a battery removal preventing device, wherein the battery removal preventing device automatically prevents the battery from being released from the attaching device when the motor is started and automatically allows the battery to be released from the attaching device when the motor is stopped.

7. The power tool as defined in claim 6, wherein the attaching device is defined by a battery cover to cover the battery on the body.

8. The power tool as defined in claim 6, wherein the attaching device is defined by a battery cover to cover the battery on the body and the attaching of the battery to the body is released by releasing the engagement of the battery cover on the body.

9. The power tool as defined in claim 6, wherein the attaching device is defined by a battery cover rotatably coupled to the body so as to cover the battery on the body.

10. The power tool as defined in claim 6, wherein the attaching device is defined by a lock-dial type hook to lock the battery to the body.

11. The power tool as defined in claim 6, wherein the attaching device is defined by an adapter disposed between the battery and the body.

12. A method of using a power tool wherein the power tool includes a motor that drives a tool bit, a body that houses the motor, a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor, comprising:

automatically preventing the battery from being removed from the body when the motor is being driven and automatically allowing the battery to be removed from the body only when the motor is not being driven.

13. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor, and

means for automatically preventing the battery from being removed from the body while the motor is being driven and automatically allowing the battery to be removed from the body only when the motor is not being driven.

14. The power tool as defined in claim 13, wherein the battery removal preventing means includes means for detachably locking the battery to the body, the battery locking means being adapted to lock the battery to the body when the motor is started and to release the engagement between the battery and the body only when the motor is stopped.

15. The power tool as defined in claim 13, wherein the battery removal preventing means includes means for locking the battery to the body and controlling means for outputting a lock signal and/or a lock release signal to the battery lock according to the operating state of the motor, the battery locking means being adapted to lock the battery to the body based on the lock signal outputted from the controlling means when the motor is started and to release the engagement between the battery and the body based on the lock release signal outputted from the controlling means only when the motor is stopped.

16. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

a trigger switch that is operated to start and stop the motor,

a battery lock that removably locks the battery to the body and

a trigger switch interlocking member that transmits the operational movement of the trigger switch to the battery lock so as to operate the battery lock, wherein the battery lock is adapted to lock the battery to the body via the trigger switch interlocking member when the trigger switch is operated to start the motor and to release the battery lock between the battery and the body via the trigger switch interlocking member only when the trigger switch is operated to stop the motor.

17. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

a battery lock to removably lock the battery to the body a control device that outputs a lock signal and a lock release signal to the battery lock in accordance with the operating state of the motor, wherein the battery lock is adapted to lock the battery to the body based on the lock signal outputted from the control device when the motor is started and to release the engagement between the battery and the body based on the lock release signal outputted from the control device only when the motor is stopped.

18. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

a power circuit that provides driving current from the battery to the motor,

a trigger switch that is electrically connected to a control circuit of the power tool independently of the power circuit, wherein the trigger switch is operated to start and stop the motor,

a battery lock that removably locks the battery to the body and

a trigger switch interlocking member that transmits the operational movement of the trigger switch to the battery lock so as to operate the battery lock, wherein the battery lock is adapted to lock the battery to the body via the trigger switch interlocking member when the trigger switch is operated to start the motor and to release the lock between the battery and the body via the trigger switch interlocking member only when the trigger switch is operated to stop the motor.

19. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

a battery removal preventing device that prevents the battery from being removed from the body during operation of the motor and allows the battery to be removed from the body only when the motor is stopped, and

a trigger switch that is operated to start and stop the motor, wherein the battery removal preventing device includes a battery lock to removably lock the battery to the body and a trigger switch interlocking member that transmits the operational movement of the trigger switch to the battery lock so as to operate the battery lock, the battery lock being adapted to lock the battery to the body via the trigger switch interlocking member when the trigger switch is operated to start the motor and to release the engagement between the battery and the body via the trigger switch interlocking member only when the trigger switch is operated to stop the motor.

20. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

a battery removal preventing device that prevents the battery from being removed from the body during operation of the motor and allows the battery to be removed from the body only when the motor is stopped, wherein the battery removal preventing device includes a battery lock to removably lock the battery to the body and a control device that outputs a lock signal and/or a lock release signal to the battery lock in accordance with the operating state of the motor, the battery lock being adapted to lock the battery to the body based on the lock signal outputted from the control device when the motor is started and to release the engagement between the battery and the body based on the lock release signal outputted from the control device only when the motor is stopped.

21. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor,

a battery removal preventing device that prevents the battery from being removed from the body during operation of the motor and allows the battery to be removed from the body only when the motor is stopped, and

a power circuit that provides driving current from the battery to the motor, a trigger switch that is electrically connected to a control circuit of the power tool independently of the power circuit, the trigger switch being operated to start and stop the motor, wherein the battery removal preventing device includes a battery lock to removably lock the battery to the body and a trigger switch interlocking member that transmits the operational movement of the trigger switch to the battery lock so as to operate the battery lock, the battery lock being adapted to lock the battery to the body via the trigger switch interlocking member when the trigger switch is operated to start the motor and to release the engagement between the battery and the body via the trigger switch interlocking member only when the trigger switch is operated to stop the motor.

22. A power tool comprising:

a motor that drives a tool bit,

a body that houses the motor,

a battery detachably coupled to the body, wherein the battery supplies driving current to operate the motor, and

means for preventing the battery from being removed from the body during operation of-the motor while allowing the battery to be removed from the body only when the motor is stopped, wherein the battery removal preventing means includes means for locking the battery to the body and controlling means for outputting a lock signal and/or a lock release signal to the battery lock according to the operating state of the motor, the battery locking means being adapted to lock the battery to the body based on the lock signal outputted from the controlling means when the motor is started and to release the engagement between the battery and the body based on the lock release signal outputted from the controlling means only when the motor is stopped.