SWITCHABLE ANTI-LOCK CONTROL

• US 20090065225A1
• Filed: 09/04/2008
• Published: 03/12/2009
• Est. Priority Date: 09/07/2007
• Status: Abandoned Application

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Wheaton, Kyle J., Forster, Michael K.
• Application Number:
  US12/204,229
• Publication Number:
  US 20090065225A1
• Time in Patent Office: Days
• US Class Current: 173/2
• CPC Class Codes: B23Q 11/04 Arrangements preventing overload of tools, e.g. restricting load
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: F16P 3/00 Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body F16P5/00 takes precedence
• CPC Class Codes: H02H 7/0854 responsive to rate of change of current, couple or speed, e.g. anti-kickback protection H02H7/0851 takes precedence

Abstract

A power tool can include a housing and a motor assembly in the housing. The motor assembly can include an output member and a motor for translating the output member. A kickback sensor can sample successive periods of current through the motor and produce an output in response thereto. An anti-kickback control device can remove energy from the output member in response to the output of the kickback sensor. A switch can have a first setting and a second setting. The first setting can correspond to a first operating condition of the anti-kickback control device. The second setting can correspond to a second operating condition of the anti-kickback control device.

Claims

1. A power tool comprising:

a housing;

a motor assembly in the housing, the motor assembly including an output member and a motor for translating the output member;

a kickback sensor that senses an operational rate of change of one of the motor and output member and produces an output in response thereto;

an anti-kickback control device that removes energy from the output member in response to the output of the kickback sensor; and

a switch having a first setting and a second setting, the first setting corresponding to a first operating condition of the anti-kickback control device and the second setting corresponding to a second operating condition of the anti-kickback control device.

2. The power tool of claim 1 wherein the kickback sensor samples successive periods of current through said motor.

3. The power tool of claim 1 wherein the first operating condition of the anti-kickback control device includes an “

OFF”

setting wherein the anti-kickback control device is turned off.

4. The power tool of claim 2 wherein the first operating condition includes a first threshold corresponding to a first rate of current change and the second operating condition includes a second threshold corresponding to a second rate of current change.

5. The power tool of claim 1, further comprising a visual indicator, wherein the anti-kickback control device communicates a signal to the visual indicator based on the output of the kickback sensor.

6. The power tool of claim 1 wherein the switch comprises a slidable switch configured on an upper portion of the housing.

7. The fastening tool of claim 1, further comprising a reset switch in electrical communication with the anti-kickback control device, the reset switch operable to restart the power tool subsequent to a kickback condition being cleared.

8. The power tool of claim 3 wherein the switch has a third setting corresponding to a third threshold and a third rate of current change.

9. A power tool comprising:

a housing;

a motor assembly in the housing, the motor assembly including an output member and a motor for translating the output member;

a kickback sensor that samples successive periods of current through said motor and produces an output in response thereto;

an anti-kickback control device that stops the motor in response to the output of the kickback sensor; and

a visual indicator, wherein the anti-kickback control device communicates a signal to the visual indicator based on the output of the kickback sensor.

10. The power tool of claim 9, further comprising a switch having a first setting and a second setting, the first setting corresponding to a first operating condition of the anti-kickback control device and the second setting corresponding to a second operating condition of the anti-kickback control device.

11. The power tool of claim 10 wherein the first operating condition of the anti-kickback control device includes an “

OFF”

setting wherein the anti-kickback control device is turned off.

12. The power tool of claim 10 wherein the first operating condition includes a first threshold corresponding to a first rate of current change and the second operating condition includes a second threshold corresponding to a second rate of current change.

13. The power tool of claim 10 wherein the switch comprises a slidable switch configured on an upper portion of the housing.

14. The fastening tool of claim 10, further comprising a reset switch in electrical communication with the anti-kickback control device, the reset switch operable to restart the power tool subsequent to a kickback condition being cleared.

15. The power tool of claim 10 wherein the switch has a third setting corresponding to a third threshold and a third rate of current change.

16. A method of eliminating kickback in a power tool of the type having an output spindle driven by an electric motor, the electric motor being supplied with current from an AC source, the method comprising:

sampling successive periods of current through the motor;

determining a rate of change of the current in response to the sampling;

comparing the rate of change to a threshold;

determining a selected position of a user actuated control switch having at least a first position and a second position; and

removing energy from the output spindle in response to the comparison and the position of the user actuated control switch.

17. The method of claim 16 wherein removing the energy includes inhibiting the supply of current to the motor if the rate of change exceeds the threshold.

18. The method of claim 16 wherein removing the energy includes applying a brake to the motor if the rate of change exceeds the threshold.

19. The method of claim 16, further comprising:

illuminating a light source based on the rate of change comparison.

20. The method of claim 16 wherein determining the position of the user actuated switch includes assigning a first threshold to the first position and a second threshold to the second position, the first and second thresholds corresponding to different rates of current change.