DRIVING TOOL AND METHOD FOR CONTROLLING SAME

• US 20080223894A1
• Filed: 03/16/2007
• Published: 09/18/2008
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Gross, Paul G., Elligson, Jeffrey A., Kenney, James J., Cruise, Nathan
• Granted Patent: US 7,646,157 B2
• Time in Patent Office: Days
• US Class Current: 227/2
• CPC Class Codes: B25C 1/008 Safety devices
• CPC Class Codes: B25C 1/06 operated by electric power

Abstract

A method for controlling a driving tool having a power source, a driver, an actuator, a follower, and a control unit. The power source includes a motor and a flywheel that is driven by the motor. The actuator is configured to selectively move the follower to push the driver into frictional engagement with a surface of the flywheel. The control unit is configured to selectively activate the electric motor and the actuator. The control unit includes a speed sensor that is configured to sense a rotational speed of an element of the power source and produce a speed signal in response thereto. The method includes: directly determining a rotational speed of an element in the power source; controlling electrical power provided to the motor based on the rotational speed of the element in the power source to cause the flywheel to rotate at a predetermined speed; and actuating the actuator when a set of actuating criteria has been met, the set of actuating criteria not including a rotational speed of the element.

Claims

1. A method for controlling a driving tool having a power source, a driver, an actuator, a follower, and a control unit, the power source including a motor and a flywheel that is driven by the motor, the actuator operable for selectively moving the follower to push the driver into frictional engagement with a surface of the flywheel, the control unit operable for selectively activating the electric motor and the actuator, the control unit including a speed sensor that is configured to sense a rotational speed of an element of the power source and produce a speed signal in response thereto, the method comprising:

directly determining a rotational speed of an element in the power source;

controlling electrical power provided to the motor based on the rotational speed of the element in the power source to cause the flywheel to rotate at a predetermined speed; and

actuating the actuator when a set of actuating criteria has been met, the set of actuating criteria not including a rotational speed of the element.

2. The method of claim 1, wherein the speed sensor is a non-contact type sensor.

3. The method of claim 2, wherein the non-contact type sensor is a Hall-effect sensor.

4. The method of claim 3, wherein the element is a magnet.

5. The method of claim 4, wherein the magnet is coupled for rotation with the flywheel.

6. The method of claim 2, wherein the non-contact type sensor is an Eddy current sensor.

7. The method of claim 1, wherein the control unit further comprises a trigger switch and a contact trip switch, the trigger switch providing a trigger signal in response to actuation of a trigger, the contact trip switch providing a contact trip signal in response to actuation of a contact trip mechanism, and wherein the control unit causes electrical power to be transmitted to the motor when the trigger signal is generated, when the contact trip signal is generated and when both the trigger signal and the contact trip signal are generated.

8. The method of claim 1, further comprising electrically coupling a battery pack to the driving tool, the battery pack providing electrical power for the power source, the actuator and the controller.

9. The method of claim 8, further comprising determining whether the battery pack has insufficient electrical power to cause the motor to drive the flywheel at the predetermined rotational speed.

10. The method of claim 9, further comprising generating a recharge signal to indicate that the battery pack should be recharged.

11. The method of claim 10, wherein the recharge signal is a visual signal that is communicated to a user of the driving tool.

12. The method of claim 11, wherein the visual signal is generated by an illuminated light.

13. The method of claim 10, wherein the recharge signal is generated prior to actuating the actuator.

14. A driving tool comprising:

a power source including a motor and a flywheel that is driven by the motor;

a driver;

a follower;

an actuator operable for selectively moving the follower to push the driver into frictional engagement with a surface of the flywheel; and

a control unit operable for selectively activating the electric motor and the actuator, the control unit including a speed sensor that is configured to sense a rotational speed of an element of the power source and produce a speed signal in response thereto

wherein the control unit directly determines a rotational speed of an element in the power source and controls electrical power provided to the motor based on the rotational speed of the element in the power source to cause the flywheel to rotate at a predetermined speed; and

wherein the control unit actuates the actuator when a set of actuating criteria has been met, the set of actuating criteria not including a rotational speed of the element.

15. The driving tool of claim 14, wherein the speed sensor is a non-contact type sensor.

16. The driving tool of claim 15, wherein the non-contact type sensor is a Hall-effect sensor.

17. The driving tool of claim 16, wherein the element is a magnet.

18. The driving tool of claim 17, wherein the magnet is coupled for rotation with the flywheel.

19. The driving tool of claim 14, wherein the control unit further comprises a trigger switch and a contact trip switch, the trigger switch providing a trigger signal in response to actuation of a trigger, the contact trip switch providing a contact trip signal in response to actuation of a contact trip mechanism, and wherein the control unit causes electrical power to be transmitted to the motor when the trigger signal is generated, when the contact trip signal is generated and when both the trigger signal and the contact trip signal are generated.

20. The driving tool of claim 14, further comprising a battery pack that is electrically coupled to the power source, the actuator and the controller for providing electrical power thereto.