Activation arm assembly method

• US 7,165,305 B2
• Filed: 03/31/2005
• Issued: 01/23/2007
• 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: Schell, Craig A., Kenney, James J.
• Primary Examiner(s): Omgba; Essama
• Application Number:
  US11/095,730
• Publication Number:
  US 20050217876A1
• Time in Patent Office: 663 Days
• Field of Search: 294/34, 294/69, 297/98, 292/435, 292/435.3, 227/129, 227/138, 227/156, 227/133, 227/120, 227/131, 227/146, 173/13, 173/15, 173/124, 173/122, 173/216, 173/217, 173/1
• US Class Current: 29/434
• CPC Class Codes: B25C 1/06 operated by electric power
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts
• CPC Class Codes: Y10T 29/49904 Assembling a subassembly, then assembling with a second subassembly

Abstract

A method for assembling an activation arm assembly for a power tool, such as a fastening tool or nailer. The method includes the mounting of various components of the activation arm assembly on pivot pins and positioning of a pair of arm members to load a spring that biases one of the arm members relative to another of the arm members.

Claims

1. A method for assembling an activation arm assembly for use in a power tool with a flywheel and a driver, the method comprising:

providing a first arm, a second arm and a third arm, each of the first and second arms having a pair of laterally spaced apart arm members, the third arm including a first eccentric and a second eccentric, each of the first and second eccentrics including a pin portion;

coupling a follower to the first eccentric;

providing a yoke with a cross-bar portion;

coupling the cross-bar portion to the pin portion of the first eccentric such that the yoke is rotatable about the pin portion of the first eccentric;

coupling the second eccentric to the cross-bar portion and the follower to form a subassembly;

pivotally coupling the subassembly to the second arm;

placing a spring proximate the yoke;

engaging a spacer to the arm members of the second arm, the spacer abutting and compressing the spring such that the spring biases the cross-bar portion away from the spacer;

installing a pivot pin through the first and second arms;

loading a second spring to the first arm; and

rotating the second arm about the pivot pin to load the second spring.

2. The method of claim 1, wherein coupling the follower to the first eccentric includes:

providing an axle;

fitting the follower over the axle; and

coupling the axle to the first eccentric.

3. The method of claim 2, wherein the axle includes a non-circular end that is received into a correspondingly shaped aperture formed in the first eccentric.

4. The method of claim 1, wherein each of the first and second eccentrics includes a stop member and the arm members of the second arm include range limit slots and wherein each stop member is disposed in a respective one of the range limit slots when the subassembly is pivotally coupled to the second arm.

5. The method of claim 1, wherein the arm members of the second arm include opposite edges and wherein the spacer includes a pair of flange members, the opposite edges and the flange members cooperating to guide the spacer as the spacer is engaged to the second arm.

6. The method of claim 5, wherein the opposite edges are tapered.

7. The method of claim 5, wherein at least one of the arm members of the second arm includes a notch and the spacer includes a corresponding locking element that engages the notch to thereby engage the spacer to the second arm.

8. The method of claim 5, wherein one of the spacer and the second arm includes a plurality of notches and the other one of the spacer and the second arm includes a plurality of locking elements, the locking elements engaging the notches to thereby engage the spacer to the second arm.

9. The method of claim 1, wherein the yoke includes a member that is generally transverse to the cross-bar portion and wherein placing the spring proximate the yoke comprises disposing the spring over the transverse member.

10. The method of claim 9, wherein as the spacer is engaged to the second arm, the spring and the transverse member are at least partially received into an aperture that is formed in the spacer.

11. The method of claim 1, wherein the first and second arms are locked to one another when the second spring is loaded.

12. The method of claim 11, wherein the first arm includes a rotational stop that is received into a stop aperture that is formed in the second arm and wherein location of the rotational stop in the stop aperture locks the first and second arms to one another.

13. The method of claim 1, wherein the second spring is a leaf spring.

14. The method of claim 1, further comprising installing a cam follower to the arm members of the first arm.

15. A method for assembling an activation arm assembly for use in a power tool with a flywheel and a driver, the method comprising:

providing a first arm, a second arm and a third arm, each of the first and second arms having a pair of laterally spaced apart arm members, each of the arm members including a rotational stop, each of the arm members of the second arm including a range limit slot, an axle stub aperture, an assembly notch and a stop aperture, the third arm including a first eccentric and a second eccentric, each of the first and second eccentrics including a pin portion, an axle aperture, an axle stub and a stop member;

assembling a follower to an axle;

installing the axle to the axle aperture of the first eccentric;

providing a yoke with a cross-bar portion and a member that extends from the cross-bar portion;

coupling the cross-bar portion to the pin portion of the first eccentric such that the yoke is rotatable about the pin portion of the first eccentric;

coupling the second eccentric to the axle and the yoke such that the axle is received in the axle aperture that is formed in the second eccentric and the cross-bar portion of the yoke is pivotally coupled to the pin portion of the second eccentric, the first and second eccentrics, the axle, the follower and the yoke forming at least a portion of a subassembly;

pivotally coupling the subassembly to the second arm such that each of the axle stubs are received into the stub apertures and the stop members are received into the range limit slots;

installing a spring over the member of the yoke;

providing a spacer with a pair of flanges, an aperture and at least one locking element;

engaging the flanges to opposite sides of the arm members of the second arm;

sliding the spacer along the second arm such that the flanges cooperate with opposite edges of the arm members of the second arm to guide the spacer into a position where the at least one locking element locks into the assembly notches, wherein the spring and the member are at least partially received into the aperture and the spring biases the subassembly in a predetermined rotational direction when the at least one locking element is locked into the assembly notches;

installing a pivot pin through the first and second arms;

loading a second spring to the first arm; and

rotating the second arm about the pivot pin to load the second spring and position the rotational stops within the stop apertures.