Reciprocating Saw Blade Having Variable-Height Teeth and Related Method

• US 20080307936A1
• Filed: 12/21/2007
• Published: 12/18/2008
• Est. Priority Date: 06/12/2007
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Irwin Industrial Tool Company (Stanley Black & Decker, Inc.)
• Inventors: Korb, William B., Hampton, Stephen A., Elliston, Asif
• Granted Patent: US 8,210,081 B2
• Time in Patent Office: Days
• US Class Current: 83/13
• CPC Class Codes: B23D 61/121 Types of set; Variable teeth, e.g. variable in height or gullet depth; Varying pitch; Details of gullet
• CPC Class Codes: Y10T 83/04 Processes
• CPC Class Codes: Y10T 83/9319 Toothed blade or tooth therefor
• CPC Class Codes: Y10T 83/9346 Uniformly varying teeth or tooth spacing
• CPC Class Codes: Y10T 83/935 Plural tooth groups
• CPC Class Codes: Y10T 83/9355 Including intermediate raker tooth
• CPC Class Codes: Y10T 83/9454 Reciprocable type

Abstract

A reciprocating saw blade, for use in a portable power reciprocating saw including a chuck for releasably engaging the saw blade, includes a tang having an elongated axis and being engageable with the chuck for attaching the saw blade to the reciprocating saw. The saw further includes a blade portion having a cutting edge that defines a plurality of cutting teeth. The cutting teeth define a repeating pattern of successive groups of teeth. Each group of teeth is less than about a half inch in length, and includes a plurality of laterally offset teeth, at least one relatively high first tooth and at least one relatively low second tooth. Prior to tooth set, the at least one relatively high first tooth is at least about 0.002 inch higher than the at least one relatively low second tooth.

Claims

1. A reciprocating saw blade for use in a portable power reciprocating saw including a chuck for releasably engaging the saw blade, the reciprocating saw blade comprising:

a tang having an elongated axis and being engageable with the chuck of the reciprocating saw for attaching the saw blade to the reciprocating saw; and

a blade portion having a cutting edge defined by a plurality of cutting teeth, wherein the cutting teeth define a repeating pattern of successive groups of teeth, each group of teeth is less than about a half inch in length, includes a plurality of set teeth, at least one relatively high tooth, and at least one relatively low tooth, and wherein prior to tooth set the at least one relatively high tooth is at least about 0.002 inch higher than the at least one relatively low tooth.

2. A reciprocating saw blade as defined in claim 1, wherein prior to tooth set the difference in height between the at least one relatively high tooth and the at least one relatively low tooth is within the range of about 0.003 inch to about 0.006 inch.

3. A reciprocating saw blade as defined in claim 1, wherein the relatively high teeth define at least one first clearance angle, and the relatively low teeth define at least one second clearance angle that is greater than the first clearance angle.

4. A reciprocating saw blade as defined in claim 2, wherein the first clearance angle is less than or equal to about 35°

, and the second clearance angle is greater than about 35°

.

5. A reciprocating saw blade as defined in claim 1, wherein the first clearance angle is within the range of about 25°

to about 35°

, and the second clearance angle is within the range of about 35°

to about 45°

.

6. A reciprocating saw blade as defined in claim 1, wherein each group of teeth includes at least one unset leading tooth, and a plurality of set trailing teeth.

7. A reciprocating saw blade as defined in claim 6, wherein the at least one unset leading tooth is a relatively high tooth, and at least one of the plurality of set trailing teeth is a relatively low tooth.

8. A reciprocating saw blade as defined in claim 7, wherein at least one of the set trailing teeth is a relatively high tooth.

9. A reciprocating saw blade as defined in claim 1, wherein a plurality of the set trailing teeth define different set magnitudes relative to each other.

10. A reciprocating saw blade as defined in claim 9, wherein the plurality of set trailing teeth includes at least one first set tooth defining a relatively heavy set magnitude, and at least one second set tooth defining a relatively light set magnitude.

11. A reciprocating saw blade as defined in claim 10, wherein the at least one first set tooth defining a heavy set magnitude is a relatively low tooth, and the at least one second set tooth defining a relatively light set magnitude is higher than the heavy set tooth.

12. A reciprocating saw blade as defined in claim 11, wherein the at least one relatively low heavy set tooth defines a steeper clearance angle in comparison to the at least one relatively high light set tooth.

13. A reciprocating saw blade as defined in claim 1, wherein each group of teeth includes unset teeth between first and second pluralities of set teeth.

14. A reciprocating saw blade as defined in claim 13, wherein each of the first and second pluralities of set teeth includes at least one relatively high set tooth, and at least one relatively low set tooth.

15. A reciprocating saw blade as defined in claim 14, wherein the unset teeth define at least one first clearance angle, the set teeth define at least one second clearance angle, and the at least one first clearance angle is less than the at least one second clearance angle.

16. A reciprocating saw blade as defined in claim 1, wherein the reciprocating saw causes the saw blade to move in a reciprocating motion between a rear most position and a forward most position, the reciprocating motion defines an axis of motion extending between i) a first position of a reference point of the saw blade when the saw blade is in the rear most position and ii) a second position of the reference point when the saw blade is in the forward most position, the cutting edge defines an approximate cutting line extending between the tips of successive teeth having substantially the same height, and the cutting line is oriented at an acute angle of greater than about 3°

relative to the axis of motion.

17. A reciprocating saw blade as defined in claim 16, wherein the acute angle is within the range of about 4½

°

to about 6°

.

18. A reciprocating saw blade as defined in claim 16, wherein the tang defines an elongated axis oriented at an acute tang angle relative to the cutting line which at least contributes to orienting the cutting line at an acute angle of greater than about 3°

relative to the axis of motion.

19. A reciprocating saw blade as defined in claim 16, wherein the relatively high teeth define at least one first clearance angle within the range of about 25°

to about 35°

, the relatively low teeth define at least one second clearance angle within the range of about 35°

to about 45°

, the tang angle is greater than about 3° and

less than or equal to about 6°

, and the difference in height between the at least one relatively high tooth and the at least one relatively low tooth is at least about 0.003 inch.

20. A reciprocating saw blade as defined in claim 1, wherein each group includes at least one first relatively high unset tooth, a first plurality of set teeth following the first relatively high unset tooth and set to one side of the blade portion, at least one second relatively high unset tooth following the first plurality of set teeth, and a second plurality of set teeth following the at least one second relatively high unset tooth and set to an opposite side of the blade portion relative to the first plurality of set teeth.

21. A reciprocating saw blade as defined in claim 20, wherein a plurality of at least one of the first and second pluralities of set teeth define different set magnitudes and different heights relative to each other.

22. A reciprocating saw blade as defined in claim 21, wherein at least one of the first and second pluralities of set teeth includes at least one intermediate height tooth that is relatively light set, and at least one low tooth that is relatively heavy set, wherein the intermediate height tooth defines a height between the heights of the relatively high and low teeth, and the difference in height between each intermediate height tooth and adjacent high and low teeth prior to tooth set is at least about 0.002 inch.

23. A reciprocating saw blade as defined in claim 1, wherein each group of teeth defines a variable pitch pattern, including at least one relatively coarse pitch and at least one relatively fine pitch.

24. A reciprocating saw blade as defined in claim 23, wherein each group of teeth includes an unset raker tooth defining a relatively coarse pitch.

25. A reciprocating saw blade as defined in claim 1, wherein each group of teeth includes a plurality of low teeth, and each low tooth includes a rake face defining a positive rake angle.

26. A reciprocating saw blade for use in a portable power reciprocating saw, the reciprocating saw blade comprising:

first means engageable with the reciprocating saw for attaching the saw blade to the reciprocating saw; and

a cutting edge defined by a plurality of second means for cutting, wherein the second means define a repeating pattern of successive groups thereof, each group is less than about a half inch in length, includes a plurality of second means laterally set to opposite sides of the cutting edge relative to each other, at least one relatively high second means, and at least one relatively low second means, and wherein prior to being laterally set the at least one relatively high second means is at least about 0.002 inch higher than the at least one relatively low second means.

27. A reciprocating saw as defined in claim 26, wherein the first means is a tang and each second means is a tooth.

28. A reciprocating saw as defined in claim 27, wherein the reciprocating saw causes the reciprocating saw blade to move in a reciprocating motion between a rear most position and a forward most position, the motion defines an axis of motion extending between i) a first position of a reference point of the saw blade when the saw blade is in the rear most position and ii) a second position of the reference point when the saw blade is in the forward most position, the cutting edge defines an approximate cutting line extending between of successive second means having substantially the same height, and the reciprocating saw blade further includes means for orienting the cutting line at an acute angle of greater than about 3°

relative to the axis of motion.

29. A method comprising the following steps:

mounting within the chuck of a reciprocating saw a reciprocating saw blade including a tang having an elongated axis and a blade portion having a cutting edge defined by a plurality of cutting teeth;

wherein the cutting teeth define a repeating pattern of successive groups of teeth, each group of teeth is less than about a half inch in length, and includes a plurality of teeth of different species, including a plurality of set teeth, at least one relatively high tooth, and at least one relatively low tooth; and

wherein prior to tooth set the at least one relatively high tooth is at least about 0.002 inch higher than the at least one relatively low tooth;

driving the reciprocating saw blade with the reciprocating saw in a reciprocating cutting action between forward and backward strokes; and

cutting the work piece by engaging the work piece with the reciprocatingly driven reciprocating saw blade and, in turn, during each of a plurality of forward strokes, engaging multiple teeth of the same species with the work piece, bearing a relatively higher chip load with the relatively high teeth in comparison to the relatively low teeth, protecting the relatively low teeth from chipping or damage with the preceding relatively high teeth, and cutting the work piece with the relatively low teeth at a higher speed in comparison to the relatively high teeth.

30. A method as defined in claim 29, wherein the step of driving the reciprocating saw blade comprises driving the reciprocating saw blade in a reciprocating motion between a rear most position and a forward most position, wherein the reciprocating motion defines an axis of motion extending between i) a first position of a reference point of the saw blade when the saw blade is in the rear most position, and ii) a second position of the reference point when the saw blade is in the forward most position, and the cutting edge defines an approximate cutting line extending between the tips of successive teeth having substantially the same height, and further comprising the step of positioning or orienting the cutting line at an acute angle of greater than about 3°

relative to the axis of motion

31. A method as defined in claim 30, wherein the step of positioning or orienting the cutting line at an acute angle includes at least one of:

(i) providing the tang so that the elongated axis of the tang defines an acute angle relative to the cutting line, and (ii) mounting the tang within the chuck so that the cutting line is oriented at an acute angle relative to the axis of motion.