Battery management system for a cordless tool

Patent metadata

Field	Value
Publication number	US-RE45897-E
Application number	US-201414533727-A
Country	US
Kind code	E1
Filing date	Nov 5, 2014
Priority date	Apr 14, 2008
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A hand-held, battery powered tool (e.g., nutrunner, drill) includes an output head operatively connected to a motor, a plurality of battery cells, an ON/OFF start switch, a resistance sensor that measures a resistance of the output head to movement, and a controller. When the start switch is ON and the resistance sensed by the resistance sensor does not exceed a predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other and the motor in series. When the start switch is ON and the resistance sensed by the resistance sensor exceeds the predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other in parallel and to the motor.

First claim

What is claimed is:

1. A tool comprising:
an output head; a motor operatively connected to the output head; a resistance sensor that measures the output head's resistance to movement; and a controller connected to the motor and the resistance sensor, the controller being constructed and arranged to connect to a plurality of battery cells, wherein the controller is constructed and arranged to connect the plurality of battery cells to each other and the motor in series, and subsequently automatically connect the plurality of battery cells to each other in parallel and to the motor when the resistance sensed by the resistance sensor exceeds a predetermined shift resistance.

2. The tool of claim 1 , wherein:
the output head comprises a rotational output head; the resistance sensor comprises a torque sensor that measures a torque applied to the output head; the predetermined shift resistance comprises a predetermined shift torque.

3. The tool of claim 2 , wherein:
the controller is constructed and arranged to disconnect the motor from the plurality of battery cells when the sensed torque exceeds a predetermined target torque, and the predetermined target torque is larger than the predetermined shift torque.

4. The tool of claim 1 , further comprising a fixed ratio transmission disposed between the motor and the output head.

5. The tool of claim 1 , wherein the controller comprises an electronic control unit.

6. The tool of claim 1 , wherein the resistance sensor comprises a torque sensor.

7. The tool of claim 1 , wherein the resistance sensor comprises a force sensor.

8. The tool of claim 1 , wherein:
the tool further comprises a start switch having ON and OFF positions, the start switch being operatively connected to the controller; and the controller is constructed and arranged to connect the plurality of battery cells to each other and to the motor in series in response to the start switch moving into its ON position.

9. The tool of claim 1 , wherein:
the tool further comprises a start switch having ON and OFF positions, the start switch being operatively connected to the controller; and the controller is constructed and arranged such that when the start switch is in its ON position and the resistance sensed by the resistance sensor exceeds the predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other in parallel and to the motor.

10. The tool of claim 1 , wherein:
the tool further comprises a start switch having ON and OFF positions, the start switch being operatively connected to the controller; and the controller is constructed and arranged such that when the start switch is in its ON position and the resistance sensed by the resistance sensor does not exceed the predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other and the motor in series.

11. The tool of claim 1 , wherein:
the tool further comprises a start switch having ON and OFF positions, the start switch being operatively connected to the controller; the controller is constructed and arranged to automatically disconnect the motor from the plurality of battery cells any time that the start switch moved into its OFF position.

12. The tool of claim 1 , further comprising a plurality of battery cells connected to the controller.

13. A tool comprising:
an output head; a motor operatively connected to the output head; a start switch having ON and OFF positions; a resistance sensor that measures the output head's resistance to movement; and a controller connected to the motor, the start switch, and the resistance sensor, the controller being constructed and arranged to connect to a plurality of battery cells, wherein the controller is constructed and arranged such that when the start switch is in its ON position and the resistance sensed by the resistance sensor does not exceed a predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other and the motor in series, and the controller is constructed and arranged such that when the start switch is in its ON position and the resistance sensed by the resistance sensor exceeds the predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other in parallel and to the motor.

14. The tool of claim 13 , wherein:
the output head comprises a rotational output head; the resistance sensor comprises a torque sensor that measures a torque applied to the output head; the predetermined shift resistance comprises a predetermined shift torque.

15. A method of using a battery powered tool, comprising:
(a) connecting a plurality of battery cells to each other and to a motor in series; and (b) automatically connecting the plurality of battery cells to each other in parallel and to the motor in response to a resistance sensor sensing that a resistance of an output head to movement exceeds a predetermined shift resistance.

16. The A method of claim 15 , using a battery powered tool, comprising:
(a) connecting a plurality of battery cells to each other and to a motor in series; and
(b) automatically connecting the plurality of battery cells to each other in parallel and to the motor in response to a resistance sensor sensing that a resistance of an output head to movement exceeds a predetermined shift resistance,
wherein:
the tool comprises a fastener tightening tool that includes a start switch having ON and OFF positions;
the output head comprises a rotational output head;
the resistance sensor comprises a torque sensor that measures a torque being applied to the output head;
the predetermined shift resistance comprises a predetermined shift torque; and
the method further comprises:
sensing that the start switch is in its ON position, wherein the connecting of the plurality of battery cells to each other and to motor in series occurs in response to the sensing that the start switch is in its ON position;
after automatically connecting the plurality of battery cells to each other in parallel and to the motor, automatically disconnecting the motor from the plurality of battery cells in response to the torque sensor sensing that the torque exceeds a predetermined target torque.

17. The method of claim 16 , wherein:
the start switch remains in its ON position from when battery cells are connected to each other and to the motor in series until when the motor is disconnected from the plurality of battery cells in response to the torque sensor sensing that the torque exceeds the predetermined target torque, and
the predetermined target torque exceeds the predetermined shift torque.

18. The A method of claim 15 , using a battery powered tool, comprising:
(a) connecting a plurality of battery cells to each other and to a motor in series; and
(b) automatically connecting the plurality of battery cells to each other in parallel and to the motor in response to a resistance sensor sensing that a resistance of an output head to movement exceeds a predetermined shift resistance,
wherein:
the tool includes a start switch having ON and OFF positions; and
the method further comprises:
sensing that the start switch is in its ON position, wherein the connecting of the plurality of battery cells to each other and to motor in series occurs in response to the sensing that the start switch is in its ON position; and
automatically disconnecting the motor from the plurality of battery cells any time that t

Assignees

• Stanley Black & Decker Inc

Inventors

• Naumann Natalie A
• Bookshar Duane R
• Demchak Leonard V

Classifications

• H02J7/971

  the charge cycle being controlled or terminated in response to non-electric parameters · CPC title

• H02J7/575

  Parallel/serial switching of connection of batteries to charge or load circuit · CPC title

• H02J7/0063

  Electricity · mapped topic

• H02J7/0024

  Electricity · mapped topic

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title