System, apparatus, and method for blade clearance tuning

• US 6,415,515 B1
• Filed: 12/30/1999
• Issued: 07/09/2002
• Est. Priority Date: 12/30/1999
• Status: Expired due to Fees

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Black & Decker Corporation (Stanley Black & Decker, Inc.)
• Inventors: Wheeler, Dale K., Lessig, William R. III
• Primary Examiner(s): Hughes, S. Thomas
• Assistant Examiner(s): COMPTON, ERIC B
• Application Number:
  US09/475,069
• Time in Patent Office: 922 Days
• Field of Search: 294/34, 836/65, 836/66, 836/984.1, 836/992.1, 302/08, 302/09, 305/02, 403/388, 403/188, 403/192, 403/194
• US Class Current: 30/208
• CPC Class Codes: A01G 3/053 motor-driven
• CPC Class Codes: F16B 5/025 specially designed to compensate for misalignement or to eliminate unwanted play
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts
• CPC Class Codes: Y10T 29/49948 Multipart cooperating fastener [e.g., bolt and nut]
• CPC Class Codes: Y10T 29/5343 Means to drive self-piercing work part
• CPC Class Codes: Y10T 29/5397 and assembling press [e.g., truss assembling means, etc.]
• CPC Class Codes: Y10T 29/53996 by deforming
• CPC Class Codes: Y10T 83/9464 For rotary tool
• CPC Class Codes: Y10T 83/9481 Tool is single element reciprocable along elongate cutting edge [e.g., saw blade, etc.]

Abstract

When connecting two elements that are moveable with respect to one another, some amount of clearance, i.e., spacing between the elements, is included to minimize friction between the elements. The present invention is directed to setting the clearance within a desired range, regardless of manufacturing tolerances of the two elements. In particular, the present invention is directed to power cutting tools wherein it is necessary to set the clearance between one or more reciprocating blades and a blade support member.

Claims

1. A system for setting a clearance between relatively movable elements, the system comprising:

a first element;

a second element relatively movable with respect to said first element; and

a third element penetrating said second element along an axis, said third element being fixed against axial displacement with respect to said first element, and said third element having;

a first axial portion extending a first dimension along said axis between first and second axial ends, said first dimension exceeding a thickness of said second element along said axis, and

a second axial portion being connected to said first axial portion at said second axial end and having an enlarged radial dimension relative to said first portion, said second element being interposed between said first element and said second portion;

whereby said first axial end extends into a depression in said first element, said depression having a second dimension that is less than the difference between said first dimension and said thickness by a specified amount,

wherein a tolerance of said specified amount is substantially independent of a tolerance of said thickness.

2. The system according to claim 1, wherein said second axial portion includes a flange extending orthogonally with respect to said axis.

3. The system according to claim 1, wherein axial clearance between said first element, said second element, and said second portion is equal to said first dimension less a combined total of said thickness and said second dimension.

4. The system according to claim 3, wherein said axial clearance is said specified amount.

5. The system according to claim 1, further comprising:

a fastener fixing said third element to said first portion.

6. The system according to claim 5, wherein said fastener includes a bolt threadably engaging a nut.

7. The system according to claim 1, wherein said first element includes a substantially planar major surface and said depression includes a dimple in said major surface.

8. The system according to claim 1, further comprising:

a fourth element relatively movable with respect to said first and second elements;

whereby said third element penetrates said second and fourth elements along said axis.

9. The system according to claim 1, wherein said tolerance of said specified amount is approximately ±

0.005 inches.

13. The system according to claim 3, wherein said axial clearance is said specified amount.

10. A system for setting blade clearance in a power cutting tool, the system comprising:

a blade support member;

a first cutting blade relatively movable with respect to said blade support member;

a second cutting blade relatively moveable with respect to said blade support member and with respect to said first cutting blade; and

a spacer penetrating said first and second cutting blades along an axis, said spacer being fixed against axial displacement with respect to said blade support member, and said spacer having;

a first axial portion extending a first dimension along said axis between first and second axial ends, said first dimension exceeding a combined thickness of said first and second cutting blades along said axis, and

a second axial portion being connected to said first axial portion at said second axial end and having an enlarged dimension relative to said first portion, said first and second cutting blades being interposed between said blade support member and said second portion;

whereby said first axial end extends into a depression in said blade support member, said depression having a second dimension that is less than the difference between said first dimension and said combined thickness by a specified amount,

wherein a tolerance of said specified amount is substantially independent of a tolerance of said combined thickness.

11. The system according to claim 10, further comprising:

a fastener fixing said spacer to said blade support member, said fastener including a bolt threadably engaging a nut.

12. The system according to claim 10, wherein said second cutting blade is sandwich between said blade support member and said first cutting blade.