Reciprocating Saw Blade Having Variable-Height Teeth and Related Method

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.

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 reciprocating saw blade tang having an elongated axis and being engageable with the chuck of the reciprocating saw for attaching the reciprocating saw blade to the reciprocating saw; and   a reciprocating saw 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 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 - 5 . (canceled) 
     
     
         6 . A reciprocating saw blade as defined in  claim 1 , wherein each group of teeth is less than about a half inch in length, and 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 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 acute 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 reciprocating saw blade to the reciprocating saw; and   a reciprocating saw blade 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 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 each group of teeth is less than about a half inch in length, and 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 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 a 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 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 a 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 each group of teeth is less than about a half inch in length, and 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 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. 
     
     
         32 . 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 corresponding second clearance angle substantially the same as the first clearance angle, wherein either (i) the at least one first clearance angle defines a primary clearance angle of the relatively high teeth and the at least one second clearance angle defines a primary clearance angle of the relatively low teeth; or (ii) the at least one first clearance angle defines a secondary clearance angle of the relatively high teeth and the at least one second clearance angle defines a secondary clearance angle of the relatively low teeth. 
     
     
         33 . A reciprocating saw blade as defined in  claim 32 , wherein the at least one first clearance angle defines a primary clearance angle of the relatively high teeth and the at least one second clearance angle defines a primary clearance angle of the relatively low teeth. 
     
     
         34 . A reciprocating saw blade as defined in  claim 32 , wherein the at least one first clearance angle defines a secondary clearance angle of the relatively high teeth and the at least one second clearance angle defines a secondary clearance angle of the relatively low teeth. 
     
     
         35 . A reciprocating saw blade as defined in  claim 26 , wherein the relatively high second means defines at least one first clearance angle, and the relatively low second means defines at least one corresponding second clearance angle substantially the same as the first clearance angle, wherein either (i) the at least one first clearance angle defines a primary clearance angle of the relatively high second means and the at least one second clearance angle defines a primary clearance angle of the relatively low second means; or (ii) the at least one first clearance angle defines a secondary clearance angle of the relatively high second means and the at least one second clearance angle defines a secondary clearance angle of the relatively low second means. 
     
     
         36 . A reciprocating saw blade as defined in  claim 35 , wherein the at least one first clearance angle defines a primary clearance angle of the relatively high second means and the at least one second clearance angle defines a primary clearance angle of the relatively low second means. 
     
     
         37 . A reciprocating saw blade as defined in  claim 35 , wherein the at least one first clearance angle defines a secondary clearance angle of the relatively high second means and the at least one second clearance angle defines a secondary clearance angle of the relatively low second means. 
     
     
         38 . A method as defined in  claim 29 , wherein the relatively high teeth define at least one first clearance angle, and the relatively low teeth define at least one corresponding second clearance angle substantially the same as the first clearance angle, wherein either (i) the at least one first clearance angle defines a primary clearance angle of the relatively high teeth and the at least one second clearance angle defines a primary clearance angle of the relatively low teeth; or (ii) the at least one first clearance angle defines a secondary clearance angle of the relatively high teeth and the at least one second clearance angle defines a secondary clearance angle of the relatively low teeth. 
     
     
         39 . A reciprocating saw blade as defined in  claim 38 , wherein the at least one first clearance angle defines a primary clearance angle of the at least one relatively high tooth and the at least one second clearance angle defines a primary clearance angle of the at least one relatively low tooth. 
     
     
         40 . A reciprocating saw blade as defined in  claim 38 , wherein the at least one first clearance angle defines a secondary clearance angle of the at least one relatively high tooth and the at least one second clearance angle defines a secondary clearance angle of the at least one relatively low tooth. 
     
     
         41 . 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 reciprocating saw blade tang having an elongated axis and being engageable with the chuck of the reciprocating saw for attaching the reciprocating saw blade to the reciprocating saw; and   a reciprocating saw blade portion having a cutting edge defined by a plurality of cutting teeth including at least one relatively high tooth, and at least one relatively low tooth, and wherein prior to any tooth set a difference in height between the at least one relatively high tooth and the at least one relatively low tooth is at least about 0.002 inch;   wherein the at least one relatively high tooth defines a first clearance angle, and the at least one relatively low tooth defines a corresponding second clearance angle that is greater than the first clearance angle, wherein either (i) the first clearance angle defines a primary clearance angle of the at least one relatively high tooth and the second clearance angle defines a primary clearance angle of the at least one relatively low tooth; or (ii) the first clearance angle defines a secondary clearance angle of the at least one relatively high tooth and second clearance angle defines a secondary clearance angle of the at least one relatively low tooth.   
     
     
         42 . A reciprocating saw blade as defined in  claim 41 , wherein the difference in height is within the range of about 0.003 inch to about 0.006 inch. 
     
     
         43 . A reciprocating saw blade as defined in  claim 41 , wherein the first clearance angle is less than or equal to about 35°, and the second clearance angle is greater than about 35°. 
     
     
         44 . A reciprocating saw blade as defined in  claim 43 , 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°. 
     
     
         45 . A reciprocating saw blade as defined in  claim 41 , wherein the plurality of cutting teeth includes at least one unset tooth. 
     
     
         46 . A reciprocating saw blade as defined in  claim 45 , wherein the at least one unset tooth is a relatively high tooth. 
     
     
         47 . A reciprocating saw blade as defined in  claim 41 , wherein the plurality of cutting teeth includes at least one set tooth. 
     
     
         48 . A reciprocating saw blade as defined in  claim 47 , wherein the at least one set tooth is a relatively high tooth. 
     
     
         49 . A reciprocating saw blade as defined in  claim 41 , 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 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. 
     
     
         50 . A reciprocating saw blade as defined in  claim 49 , wherein the acute angle is within the range of about 4½° to about 6°. 
     
     
         51 . A reciprocating saw blade as defined in  claim 49 , 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. 
     
     
         52 . A reciprocating saw blade as defined in  claim 49 , wherein the at least on e high tooth defines the first clearance angle within the range of about 25° to about 35°, the at least one relatively low tooth defines the second clearance angle within the range of about 35° to about 45°, the acute angle is greater than about 3° and less than or equal to about 6°, and the difference in height is at least about 0.003 inch. 
     
     
         53 . A reciprocating saw blade as defined in  claim 41 , wherein the plurality of cutting teeth defines a variable pitch pattern, including at least one relatively coarse pitch and at least one relatively fine pitch. 
     
     
         54 . A reciprocating saw blade as defined in  claim 53 , wherein the plurality of cutting teeth includes an unset raker tooth defining a relatively coarse pitch. 
     
     
         55 . A reciprocating saw blade as defined in  claim 41 , wherein the plurality of cutting teeth includes a plurality of low teeth, and each low tooth includes a rake face defining a positive rake angle. 
     
     
         56 . A reciprocating saw blade as defined in  claim 41 , wherein the first clearance angle defines a primary clearance angle of the at least one relatively high tooth and the second clearance angle defines a primary clearance angle of the at least one relatively low tooth. 
     
     
         57 . A reciprocating saw blade as defined in  claim 41 , wherein the first clearance angle defines a secondary clearance angle of the at least one relatively high tooth and the second clearance angle defines a secondary clearance angle of the at least one relatively low tooth. 
     
     
         58 . 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 reciprocating saw blade to the reciprocating saw; and   a reciprocating saw blade cutting edge defined by a plurality of second means for cutting including at least one relatively high second means, and at least one relatively low second means, and wherein prior to any set a difference in height between the at least one relatively high second means and the at least one relatively low means is at least about 0.002 inch;   wherein the at least one relatively high second means defines a first clearance angle, and the at least one relatively low second means defines a corresponding second clearance angle that is greater than the first clearance angle, wherein either (i) the first clearance angle defines a primary clearance angle of the at least one relatively high second means and the second clearance angle defines a primary clearance angle of the at least one relatively low second means; or (ii) the first clearance angle defines a secondary clearance angle of the at least one relatively high second means and the second clearance angle defines a secondary clearance angle of the at least one relatively low second means.   
     
     
         59 . A reciprocating saw as defined in  claim 58 , wherein the first means is a tang and each second means is a tooth. 
     
     
         60 . A reciprocating saw as defined in  claim 59 , 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 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. 
     
     
         61 . A reciprocating saw blade as defined in  claim 58 , wherein the first clearance angle defines a primary clearance angle of the relatively high second means and the second clearance angle defines a primary clearance angle of the relatively low second means. 
     
     
         62 . A reciprocating saw blade as defined in  claim 58 , wherein the first clearance angle defines a secondary clearance angle of the relatively high second means and the second clearance angle defines a secondary clearance angle of the relatively low second means. 
     
     
         63 . A method comprising the following steps:
 mounting within a 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 including at least one relatively high tooth, and at least one relatively low tooth; and   wherein prior to any tooth set a difference in height between the at least one relatively high tooth and the at least one relatively low tooth is at least about 0.002 inch, wherein the at least one relatively high tooth defines a first clearance angle, and the at least one relatively low tooth defines a corresponding second clearance angle that is greater than the first clearance angle, wherein either (i) the first clearance angle defines a primary clearance angle of the at least one relatively high tooth and the second clearance angle defines a primary clearance angle of the at least one relatively low tooth; or (ii) the first clearance angle defines a secondary clearance angle of the at least one relatively high tooth and the second clearance angle defines a secondary clearance angle of 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 a 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 with the work piece, bearing a relatively higher chip load with the at least one relatively high tooth in comparison to the at least one relatively low tooth, protecting the at least one relatively low tooth from chipping or damage with the preceding at least one relatively high tooth, and cutting the work piece with the at least one relatively low tooth at a higher speed in comparison to the at least one relatively high tooth.   
     
     
         64 . A method as defined in  claim 63 , 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 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 
     
     
         65 . A method as defined in  claim 64 , 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. 
     
     
         66 . A reciprocating saw blade as defined in  claim 63 , wherein the first clearance angle defines a primary clearance angle of the at least one relatively high tooth and the second clearance angle defines a primary clearance angle of the at least one relatively low tooth. 
     
     
         67 . A reciprocating saw blade as defined in  claim 63 , wherein the first clearance angle defines a secondary clearance angle of the at least one relatively high tooth and the second clearance angle defines a secondary clearance angle of the at least one relatively low tooth.