Cordless power tool
AssigneeMax Co., Ltd.
InventorsShinichi Ookubo, Atsushi Matsuoka, Syuichi Ishii
Life of this patent
Estimating the term…
Abstract
A cordless power tool such as a power staple gun 1 includes a power supply circuit of an electric double layer capacitor 8 and a lithium-ion battery 11. In a standby state, the lithium-ion battery charges the electric double layer capacitor, and at a switch on time, the electric double layer capacitor supplies large current to the motor 5. By combining the lithium-ion battery with high energy density and the electric double layer capacitor capable of discharging large current, it is possible to greatly reduce the size and weight as compared with a case where a nickel-cadmium battery or a nickel-hydrogen battery is used. Besides, since the electric double layer capacitor has a very long lifetime, the running cost can also be reduced.
Claims6
A cordless power tool comprising:
- a plurality of electric double layer capacitors mounted in a tool main body as a power supply of a motor and recharge able by an external power supply;
- a charging electrode provided in the tool main body;
- a contact arm;
- a safety switch that is turned on when the contact arm is pressed;
- a trigger lever;
- and
- a trigger switch that is turned on when the trigger lever is pulled;
- when the safety switch and the trigger switch are off, the plurality of electrical double layer capacitors are connected in parallel,
- when the safety switch is turned on, the plurality of electric double layer capacitors are connected in series, and
- when the safety switch and the trigger switch are turned on, current is supplied from the plurality of electric double layer capacitors connected in series to the motor.
A cordless power tool comprising:
- a plurality of electric double layer capacitors mounted in a tool main body as a power supply of a motor and rechargeable by an external power supply;
- a charging electrode provided in the tool main body;
- a series parallel switching circuit that switches the plurality of electric double layer capacitors into parallel connection when a start switch is off, and switches the plurality of electric double layer capacitors into series connection when the start switch is on;
- a contact arm;
- a safety switch that is turned on when the contact arm is pressed;
- a trigger lever;
- and
- a trigger switch that is turned on when the trigger lever is pulled;
- when the safety switch and the trigger switch are off, the plurality of electric double layer capacitors are connected in parallel,
- when the safety switch is turned on, the plurality of electric double layer capacitors are connected in series, and
- when the safety switch and the trigger switch are turned on, current is supplied from the plurality of electric double layer capacitors connected in series to the motor.
Dependencies are inferred from the claim text.