Abstract:
A blade is usable with a reciprocating saw imparting movement to the blade in a forward direction and a rearward direction to perform a cutting operation on a workpiece. The blade includes an attachment portion configured to couple to the reciprocating saw and a body extending from the attachment portion. The body includes a first profile portion and a second profile portion extending from the first profile portion. The second profile portion has a height less than a height of the first profile portion. The blade also includes a plurality of teeth formed on the body and defining a toothed cutting edge. The blade also includes a tip portion formed at a distal end of the second profile portion and terminating in a pointed tip. The pointed tip is configured to punch a hole through the workpiece and includes a toothless cutting edge extending substantially parallel to the toothed cutting edge. The toothless cutting edge extends from the toothed cutting edge to the pointed tip.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to co-pending U.S. Provisional Patent Application No. 61/605,486 filed on Mar. 1, 2012, and U.S. Provisional Patent Application No. 61/707,156 filed on Sep. 28, 2012, the entire contents of both of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to blades for power tools, and more particularly to a blade for a reciprocating saw. 
       BACKGROUND OF THE INVENTION 
       [0003]    Reciprocating tools, such as reciprocating saws, typically include removable blades to allow for replacement of worn or damaged blades. 
       SUMMARY 
       [0004]    The invention provides, in one aspect, a blade for use with a reciprocating saw imparting movement to the blade in a forward direction and a rearward direction to perform a cutting operation on a workpiece. The blade includes an attachment portion configured to couple to the reciprocating saw and a body extending from the attachment portion. The body includes a first profile portion and a second profile portion extending from the first profile portion. The second profile portion has a height less than a height of the first profile portion. The blade also includes a plurality of teeth formed on the body and defining a toothed cutting edge. The blade also includes a tip portion formed at a distal end of the second profile portion and terminating in a pointed tip. The pointed tip is configured to punch a hole through the workpiece and includes a toothless cutting edge extending substantially parallel to the toothed cutting edge. The toothless cutting edge extends from the toothed cutting edge to the pointed tip. 
         [0005]    The invention provides, in another aspect, a reciprocating saw including a housing, a motor supported by the housing, and a blade clamp mechanism supported for reciprocating motion relative to the housing. The reciprocating saw also includes a drive mechanism connected between the motor and the blade clamp mechanism to impart reciprocating motion to the blade clamp mechanism and a blade. The blade includes an attachment portion coupled to the blade clamp mechanism and a body extending from the attachment portion. The body includes a first profile portion and a second profile portion extending from the first profile portion. The second profile portion has a height less than a height of the first profile portion. The blade also includes a plurality of teeth formed on the body and defining a toothed cutting edge. The blade also includes a tip portion formed at a distal end of the second profile portion and terminating in a pointed tip. The pointed tip is configured to punch a hole through the workpiece. The tip portion includes a toothless cutting edge extending substantially parallel to the toothed cutting edge, and the toothless cutting edge extends from the toothed cutting edge to the pointed tip. 
         [0006]    Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a side view of a reciprocating power tool for receiving a blade according to an embodiment of the invention, shown in  FIG. 1  receiving a saw blade. 
           [0008]      FIG. 2  is a cross-section of the reciprocating power tool shown in  FIG. 1  and including a shoe. 
           [0009]      FIG. 3  is a profile view of a blade according to an embodiment of the invention. 
           [0010]      FIG. 4A  is an enlarged view of a toothed portion of the blade shown in  FIG. 3 . 
           [0011]      FIG. 4B  is another enlarged view of the toothed portion of the blade shown in  FIG. 3 . 
           [0012]      FIG. 5  is a profile view of a blade according to another embodiment of the invention. 
           [0013]      FIG. 6  is an enlarged view of a toothed portion of the blade shown in  FIG. 5 . 
           [0014]      FIG. 7  is a profile view of a blade according to another embodiment of the invention. 
       
    
    
       [0015]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
       DETAILED DESCRIPTION 
       [0016]      FIGS. 1 and 2  illustrate a reciprocating power tool  10  including a blade clamp mechanism  12 . The illustrated reciprocating power tool  10  is a reciprocating saw; however, in other embodiments, other reciprocating power tools may include the invention. As shown in  FIGS. 1 and 2 , the power tool  10  includes a saw housing  14  having a forward portion  16 , a body portion  18  housing a motor  20  ( FIG. 2 ), and a handle portion  22 . The forward portion  16  of the saw housing  14  includes a blade receiving aperture or end  24  that receives a saw blade  26  ( FIG. 1 ), a blade  46  ( FIGS. 3-4B ) according to one embodiment of the invention, a blade  46 ′ ( FIGS. 5-6 ) according to another embodiment of the invention, or a blade  46 ″ ( FIG. 7 ) according to another embodiment of the invention, as will be described in greater detail below. The saw blade  26 ,  46 ,  46 ′,  46 ″ is releasably coupled to the blade clamp mechanism  12  ( FIG. 2 ) positioned within the saw housing  14 , specifically, within the receiving aperture  24 . In the illustrated embodiment, a boot or grip portion  28  is positioned over the forward portion  16  of the saw housing  14 . In this embodiment, the boot  28  provides a grip area  30  for the user and/or provides protection to the tool  10 . In some embodiments, the boot  28  is over-molded onto the forward portion  16 . The handle portion  22  includes an over-mold to define an ergonomic grip  32  and allows a user to hold and control the power tool  10 . 
         [0017]    With continued reference to  FIGS. 1 and 2 , the power tool  10  includes a trigger-type power switch  34  for activating a power supply  36  of the tool  10  and a button or switch  38  for selecting a speed level (e.g., a high speed or a low speed) for reciprocating the saw blade. In the illustrated embodiment, the power supply  36  is a rechargeable battery pack. The battery pack  36  is releasably coupled to the handle portion  22  to provide power to the power tool  10 , and is releasable away from and rearward of the handle portion  22 . In the illustrated embodiment, the battery pack  36  is an eighteen-volt (18V) rechargeable power tool battery pack. In other embodiments, the battery pack  36  may be a twelve-volt (12V), a twenty-four-volt (24V), or other various voltages. According to another embodiment, the power supply  36  may be an alternating current (AC) power provided via a corded plug electrically coupled to a wall outlet or any number of suitable powering options. 
         [0018]    With reference to the cross section illustrated in  FIG. 2 , the reciprocating tool  10  also includes a drive mechanism  40  positioned substantially within the housing  14 . The drive mechanism  40  is coupled to the motor  20  and to a spindle  42  for transferring rotational motion of a shaft of the motor  20  into reciprocating motion of the spindle  42  along a longitudinal axis X relative to the housing  14 . The blade clamp mechanism  12  is disposed at a distal end of the spindle  42  for receiving the blade. The blade clamp mechanism  12  secures the blade to the spindle  42  for reciprocation with the spindle  42  in a direction R ( FIG. 1 ), which is substantially parallel to the longitudinal axis X. In other embodiments, other suitable types and configurations of blade clamp mechanisms may be employed. 
         [0019]    The reciprocating tool  10  also includes a removable shoe  44 , illustrated in  FIG. 2 , operable to engage a work piece and provide stability to the tool  10  while cutting. The shoe  44  may be removed when the blade is attached to the blade clamp mechanism  12 . The shoe  44  typically acts as a stop to limit the depth of the saw blade  26  into the workpiece and to prevent the workpiece from engaging the saw blade  26  at a connection of the saw blade  26  to the tool  10 , e.g., at the blade clamp mechanism  12 . In some embodiments, the shoe  44  freely pivots about an axis to allow the user to adjust an angle at which the blade  26  engages the workpiece during a cut. In some embodiments, the reciprocating tool  10  may not include a shoe. 
         [0020]    In other embodiments, the power tool  10  may include various handle constructions, drive mechanisms, blade clamp mechanisms, and power configurations. In further embodiments, the power tool  10  may include other types of power and speed control switches or may not include a speed control feature. 
         [0021]      FIGS. 3-4B  illustrate the blade  46  according to an embodiment of the invention. The blade  46  is preferably formed from a bi-metal strip, or any hardened steel, and includes an attachment portion  48  and a body  50  extending from the attachment portion  48 . The attachment portion  48  includes a tang  52  and an aperture  54 , which are configured to engage with the blade clamp mechanism  12  to securely and releasably connect the blade  46  to the reciprocating tool  10 . The attachment portion  48  defines a longitudinal axis A that, when attached to the blade clamp mechanism  12 , is substantially parallel to the longitudinal axis X of reciprocation of the spindle  42 . In some embodiments, the longitudinal axis A is coincident with the longitudinal axis X when the blade  46  is attached to the blade clamp mechanism  12 . In other embodiments, other types or configurations of attachment portions may be employed in order to suit the blade clamp mechanism  12  of the reciprocating tool  10 . In yet other embodiments, other suitable materials may be used to form the blade  46 . 
         [0022]    The body  50  includes a tall profile portion  56  extending from the attachment portion  48 , a low profile portion  58  extending from the tall profile portion  56 , and a cutting edge  60  extending across the tall profile portion  56  and the low profile portion  58 . The cutting edge  60  extends substantially along a cutting plane B. The attachment portion  48  is angled with respect to the cutting edge  60  (and the cutting plane B) by a tang angle C. The tang angle C is preferably between about 0 degrees and about 6.5 degrees. In some embodiments, the tang angle C is higher, e.g., about 25 degrees. Therefore, in some embodiments, the tang angle C is between about 0 degrees and about 25 degrees. The cutting edge  60 , which may also be referred to as a toothed cutting edge  60 , includes teeth  62 , which are best illustrated in the enlarged view of  FIG. 4A . Preferably, there are between about 18 teeth per inch and about 40 teeth per inch along the cutting edge  60 . In the illustrated embodiment, there are about 30 teeth per inch. The teeth  62  have a fine-pitched V-shaped tooth form. 
         [0023]      FIGS. 4A and 4B  illustrate the teeth  62  in greater detail. Each tooth includes an angle D and an angle E with respect to the cutting edge  60  (and cutting plane B). The angle D is preferably between about 30 and about 70 degrees. The angle E is preferably between about 30 and about 70 degrees. In the illustrated construction, the angle D is about 57 degrees and the angle E is about 53 degrees. The angle E is sometimes referred to as the relief angle. A rake angle is sometimes defined as the measurement of angle D minus 90 degrees, e.g., −33 degrees in the illustrated embodiment. The tooth form also includes gullets  66  having a radius R. The radius R is preferably between about 0.005 and about 0.020 inches. In the illustrated construction, the radius R is about 0.008 inches. Each gullet  66  is spaced from an adjacent gullet  66  by a distance, or pitch, K measured parallel to the cutting edge  60 , or cutting plane B. Preferably, the pitch K is between about 0.025 and about 0.055 inches. In the illustrated embodiment, the pitch K is about 0.033 inches. The teeth  62  also have a tooth height M, defined between the tip of the teeth  62  and the peak of the gullets  66 . Preferably, the tooth height M is between about 0.010 and about 0.035 inches. The tooth height M is about 0.017 inches in the illustrated embodiment. 
         [0024]    A distal end of the blade  46  terminates in a pointed tip  64  located adjacent the cutting teeth  62  at a distal end of the toothed cutting edge  60 . The pointed tip  64  is sharp and allows the blade  46  to puncture a workpiece. A toothless cutting edge  65  extends parallel to the toothed cutting edge  60 , from the distal end of the toothed cutting edge  60  to the pointed tip  64 . The toothless cutting edge  65  allows the pointed tip  64  to puncture the workpiece without catching or binding. The pointed tip  64  includes a tip angle H of about 15 degrees to about 45 degrees. The tip angle H is about 30 degrees in the illustrated embodiment. In the illustrated embodiment, the body  50  is formed as one piece with the attachment portion  48 . In other embodiments, fasteners or fastening means may be employed, such as rivets, screws, bolts, glue, adhesives, welding, soldering and the like. 
         [0025]    The blade  46 , and more specifically, the body  50 , has a material thickness of about 0.035 inches to about 0.080 inches. The overall length L of the blade  46  is between about 2.75 inches and about 4.5 inches. A length G of the low profile portion  58  is between about  1 . 5  inches and about 3 inches. A height F of the low profile portion  58  is between about 0.25 inches and about 0.625 inches. 
         [0026]      FIGS. 5-6  illustrate a blade  46 ′ according to another embodiment of the invention. The blade  46 ′ is preferably formed from a bi-metal strip, or any hardened steel, and includes an attachment portion  48  and a body  50  extending from the attachment portion  48 , a tang  52 , an aperture  54 , a longitudinal axis A, a tall profile portion  56 ′ extending from the attachment portion  48 , a low profile portion  58 ′ extending from the tall profile portion  56 ′, a cutting edge  60 , a cutting plane B, and a pointed tip  64 , which are described in greater detail above with respect to the blade  46 . Like features, accordingly, are labeled the same as those above and need not be described in detail again. 
         [0027]    The low profile portion  58 ′ is longer than the low profile portion  58  described above, measured in a direction parallel to the cutting edge  60 . The tall profile portion  56 ′ is shorter than the tall profile portion  56  described above, measured in a direction perpendicular to the cutting edge  60 . Specifically, the low profile portion  58 ′ has a length G′, measured from the junction with the tall profile portion to the tip 64, preferably between about 1.6 inches and about 2.5 inches. In the illustrated construction, the length G′ is about 2.4 inches. The tall profile portion  56 ′ has a length N, measured from the center of the aperture  54  to the junction with the low profile portion  58 ′, preferably between about 0.43 to about 1.27 inches. In the illustrated construction, the length N is about 0.53 inches. Thus, a ratio of the length N of the tall profile portion to the length G′ of the low profile portion is between about 0.17 and about 0.79 (and is preferably about 0.22). Accordingly, the tall profile portion  56 ′ does not extend as far away from the tang  52  as in the embodiment shown in  FIGS. 3-4  such that the tall profile portion  56 ′ does not pass the shoe  44  of the reciprocating tool  10 . 
         [0028]    The blade  46 ′ also includes a toothless cutting edge  65  that extends parallel to the cutting edge  60 , from the distal end of the cutting edge  60  to the pointed tip  64 . The toothless cutting edge  65  defines a tip length J. Accordingly, the teeth  62 ′ are spaced from the pointed tip  64  by a distance equal to the tip length J. The tip length J is preferably between about 0.15 and about 0.30 inches. In the illustrated embodiment, the tip length J is about 0.23 inches. 
         [0029]    The blade  46 ′ also includes some geometry that is substantially the same as the geometry described above and, accordingly, is labeled the same and need not be described again in detail. Specifically, the blade  46 ′ includes the overall length L, the height F of the low profile portion  58 , the tang angle C, and the tip angle H. In the illustrated embodiment, the overall length L is about 3.33 inches (and preferably between about 2.75 to about 4.5 inches, as described above). Thus, a ratio of the length G′ of the low profile portion  58 ′ to the overall length L is between about 0.35 and about 0.91 (and is about 0.72 in the illustrated embodiment). The height F of the low profile portion is about 0.25 inches (and is preferably between about 0.25 to about 0.625 inches as described above). The tang angle C is preferably between about 0 and about 10 degrees. The tip angle H is about 30 degrees (and preferably between about 15 to about 45 degrees, as described above). 
         [0030]    The cutting edge  60  of the blade  46 ′ includes cutting teeth  62 ′.  FIG. 6  illustrates the tooth form of the cutting teeth  62 ′ in greater detail. In the illustrated construction, the cutting edge  60  includes about 30 teeth per inch. The teeth  62 ′ have a fine-pitched V-shaped tooth form. Each tooth includes an angle D′ and an angle E′ with respect to the cutting edge  60  (and cutting plane B). The angle D′ is preferably between about 30 and about 70 degrees. The angle E′ is preferably between about 30 and about 70 degrees. In the illustrated construction, the angle D′ is about 57 degrees and the angle E′ is about 50 degrees. The angle E′ is sometimes referred to as the relief angle. A rake angle is sometimes defined as the measurement of angle D′ minus 90 degrees, e.g., −33 degrees in the illustrated embodiment. The tooth form also includes gullets  66 ′ having a radius R′. The radius R′ is preferably between about 0.005 and about 0.020 inches. In the illustrated construction, the radius R′ is about 0.008 inches. Each gullet  66 ′ is spaced from an adjacent gullet  66 ′ by a distance, or pitch, K′ measured parallel to the cutting edge  60 , or cutting plane B. Preferably, the pitch K′ is between about 0.025 and about 0.055 inches. In the illustrated embodiment, the pitch K′ is about 0.033 inches. The teeth  62 ′ also have a tooth height M′, defined between the tip of the teeth  62 ′ and the peak of the gullets  66 ′. Preferably, the tooth height M′ is between about 0.010 and about 0.035 inches. The tooth height M′ is about 0.017 inches in the illustrated embodiment. 
         [0031]      FIG. 7  illustrates a blade  46 ″ according to another embodiment of the invention. The blade  46 ″ is substantially similar to the blade  46 ′ shown in  FIGS. 5-6  and like parts are labeled with like numerals and need not be described again. The blade  46 ″ includes a tall profile portion  56 ″ and a low profile portion  58 ″. The low profile portion  58 ″ includes steps  68  disposed between the tall profile portion  56 ″and the pointed tip  64 . 
         [0032]    The blade  46 ,  46 ′,  46 ″ is particularly well-suited for cutting duct material in heating, ventilation and air conditioning (HVAC) applications. In operation, a user attaches the blade  46 ,  46 ′,  46 ″ to the blade clamp mechanism  12  of the reciprocating power tool  10  and manually jams the pointed tip  64  into the material, similar to stabbing the material with a bayonet. The short length L of the blade  46 ,  46 ′,  46 ″ and the sharp pointed tip  64  allow the blade  46 ,  46 ′,  46 ″ to be plunged into duct material with reduced force and without substantial bending. In addition, the toothless cutting edge  65  of the tip  64  prevents the blade  46 ,  46 ′,  46 ″ from catching or binding when it is jammed into the material. The blade  46 ,  46 ′,  46 ″ is long enough so that it may remain in the cut during both the back and forward strokes. Specifically, the low profile portion  58  performs the cut and remains in the material during the back and forward strokes. Once in the material, the blade  46 ,  46 ′,  46 ″ cuts with a reciprocating action imparted by the reciprocating power tool  10 . The fine-pitched V-shaped tooth form of the teeth  62  cuts the material in both directions and reduces vibration in the duct material during cutting. The low profile section  58  allows tight radius cuts in the duct material. 
         [0033]    Thus, the invention provides, among other things, a blade attachable to a reciprocating saw for making tight radius cuts in HVAC duct material. Various features of the invention are set forth in the following claims.