Lock-out for activation arm mechanism in a power tool

• US 20050218178A1
• Filed: 03/31/2005
• Published: 10/06/2005
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Gross, Paul, Berry, Alan
• Granted Patent: US 7,331,403 B2
• Time in Patent Office: Days
• US Class Current: 227/8
• CPC Class Codes: B25C 1/06 operated by electric power

Abstract

A power tool, such as a nailer, having a driver, a flywheel and an activation arm for selectively driving the driver into contact with the flywheel to transfer energy therebetween to cause the driver to translate. The power tool includes a bar that may be moved so as to resist movement of the activation arm in a direction that would bring the driver into contact with the flywheel. A method for operating a power tool is also provided.

Claims

1. A power tool comprising:

a structure;

a flywheel coupled to the structure;

a driver;

an activation arm assembly having a first arm, a second arm, a third arm and a roller, the third arm carrying the roller and being pivotally coupled to the second arm, the second arm being pivotally coupled to the first arm, the first arm being pivotally coupled to the structure; and

a bar coupled to the structure and movable between an extended position and a retracted position;

wherein the activation arm assembly is movable between a first position, in which the roller does not initiate frictional engagement between the flywheel and the driver, and a second position, in which the roller pushes the driver into engagement with the flywheel; and

wherein positioning of the bar in the extended position inhibits the activation arm assembly from being moved from the first position to the second position, and wherein positioning of the bar in the retracted position permits the activation arm assembly to be moved from the first position to the second position.

2. The power tool of claim 1, further comprising a nosepiece and a magazine assembly that are coupled to the structure, the magazine assembly being configured to hold a plurality of fasteners and sequentially feed the fasteners into the nosepiece, the nosepiece holding a first one of the fasteners and guiding both the first one of the fasteners and the driver when the power tool is activated.

3. The power tool of claim 2, further comprising a contact trip that is slidably mounted on the nosepiece, wherein movement of the bar is coordinated with movement of the contact trip.

4. The power tool of claim 1, wherein the bar includes a rack with a plurality of teeth that engage an edge of the first arm.

5. The power tool of claim 1, further comprising at least one elastically deformable member that is coupled to the driver, the elastically deformable member being configured to move the driver to a returned position.

6. The power tool of claim 5, wherein the elastically deformable member is at least partially housed in a housing, the housing being coupled to the structure.

7. The power tool of claim 6, wherein the housing partially houses the bar.

8. The power tool of claim 7, further comprising a spring that is disposed in the housing, the spring biasing the bar toward the extended position.

9. The power tool of claim 8, wherein the housing is snap-fit to the structure.

10. A method for operating a power tool having a flywheel, a driver and an arm that carries a roller, the arm being movable between a first position, wherein the roller does not drive the driver into engagement with the flywheel, and a second position, wherein the roller drives the driver into engagement with the flywheel to permit the flywheel to transfer energy to the driver and translate the driver along a translation axis, the method comprising:

providing a bar that is movable between a first condition, which inhibits movement of the arm from the first position to the second position, and a second condition, which permits movement of the arm from the first position to the second position;

biasing the bar into the first condition; and

moving the bar into the second condition in response to a predetermined event.

11. The method of claim 10, wherein the power tool includes a nosepiece into which the driver travels and wherein the predetermined event includes positioning the nosepiece within a predetermined proximity to a workpiece.

12. The method of claim 11, wherein after the bar is moved into the second condition the method further comprises moving the arm into the second position to thereby translate the driver along the translation axis.

13. The method of claim 12, further comprising loading a fastener into the nosepiece.

14. A power tool comprising:

a structural backbone;

a flywheel coupled to the structural backbone;

a driver;

an activation arm assembly having an arm and a roller that is supported by the arm, the arm being pivotally coupled to the structural backbone;

a return mechanism having a housing and an elastically-deformable member that is coupled to the driver, the housing being coupled to the structural backbone, the elastically-deformable member being at least partially housed in the housing and operable for biasing the driver into a returned position;

a bar that is partially housed in the housing and movable between an extended position and a retracted position;

wherein the activation arm assembly is movable between a first position, in which the roller does not initiate frictional engagement between the flywheel and the driver, and a second position, in which the roller pushes the driver into engagement with the flywheel; and

wherein positioning of the bar in the extended position inhibits the activation arm assembly from being moved from the first position to the second position, and wherein positioning of the bar in the retracted position permits the activation arm assembly to be moved from the first position to the second position.

15. The power tool of claim 14, further comprising a nosepiece and a magazine assembly that are coupled to the structural backbone, the magazine assembly being configured to hold a plurality of fasteners and sequentially feed the fasteners into the nosepiece, the nosepiece holding a first one of the fasteners and guiding both the first one of the fasteners and the driver when the power tool is activated.

16. The power tool of claim 15, further comprising a contact trip that is slidably mounted on the nosepiece, wherein movement of the bar is coordinated with movement of the contact trip.

17. The power tool of claim 14, wherein the bar includes a rack with a plurality of teeth that engage an edge of the arm.

18. The power tool of claim 14, further comprising a spring that is disposed in the housing, the spring biasing the bar toward the extended position.

19. The power tool of claim 14, wherein the housing is snap-fit to the structural backbone.