US 2009/0256502 A1 · BATTERY MANAGEMENT SYSTEM FOR A CORDLESS TOOL

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.

Claims20

Dependent claims

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.

3 more elements

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.

Dependencies are inferred from the claim text.

Facts

Application

12/423,545Filed 14 Apr 2009

Priority

14 Apr 2008

Published

15 Oct 2009

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

B25F 5/00
Details or components of portable power-driven tools not particularly related to the
H02J 7/575
Acting upon multiple batteries simultaneously or sequentially: parallel/serial switching of connection of batteries to charge or load circuit
H02J 7/971
Regulation of charging or discharging current or voltage: the charge cycle being controlled or terminated in response to non-electric parameters
B25F
Combination or multi-purpose tools not otherwise provided for

Battery management system for a cordless tool

Life of this patent

Battery management system for a cordless tool

Life of this patent

Abstract

Claims20