Reciprocating saw blade

A reciprocating saw blade for use with a reciprocating saw, the saw blade including a body including a first substantially planar surface and a second substantially planar surface opposite the first surface, an attachment portion for coupling the saw blade to the reciprocating saw, a cutting edge including a plurality of cutting teeth, and a rib element including a pair of outermost rib members. One of the outermost rib members is proximate the cutting edge and the other of the outermost rib members is proximate a back edge of the blade opposite the cutting edge. Each outermost rib member includes a first portion and a second portion. The first portions of each of the ribs are substantially parallel to one another.

BACKGROUND

The invention relates to accessories for power tools, such as blades, and more particularly to a blade for a reciprocating saw. The invention also relates to stock material from which an accessory is made.

Power tools, such as reciprocating saws, typically include removable blades to allow for replacement of worn or damaged blades. Saw blades, and other accessories, are typically made from smooth sheets of coil stock material. Saw blades are used for cutting wood, metal, plastics, and other materials. A saw blade typically includes a body, one or more attachment portions, and a cutting edge. The cutting edge comprises a plurality of teeth made up of one or more tooth forms. Tooth forms on saw blades are a major factor in the durability, cost, speed of cutting, and accuracy and quality of cuts made.

During operation, the work material may cause the saw blade to bend, deforming or even breaking the blade if the blade is not thick enough to resist the bending. For example, when a saw blade is used to cut an interior corner, the blade tends to bend against the wall. This prevents the user from cutting the work piece along a straight line that is parallel to the inside wall. This problem is especially problematic on short saw blades, i.e., blades that are six inches in length or less. In addition to prohibiting a straight cut, the bending of the saw blade can deform or break the blade if the blade is not thick enough to resist the bending.

Similarly, during operation the reciprocating saw blade may bind in the work material or become caught on a nail or obstruction in the material. This binding can create a shear force that is sufficient to break off one or more teeth. As each tooth breaks off, the life of the other teeth and the life of the blade overall is dramatically decreased. As the blades wear, the user must adjust the cutting angle to create contact between alternate tooth surfaces and the work material in order to speed up the cutting time and extend the life of the blade.

SUMMARY

In one embodiment, the invention provides a reciprocating saw blade for use with a reciprocating saw. The saw blade includes a body including a first substantially planar surface and a second substantially planar surface opposite the first surface, an attachment portion for coupling the saw blade to the reciprocating saw, a cutting edge including a plurality of cutting teeth, and a rib element including a pair of outermost rib members. One of the outermost rib members is proximate the cutting edge and the other of the outermost rib members is proximate a back edge of the blade opposite the cutting edge. Each outermost rib member includes a first portion and a second portion. The first portions of each of the ribs are substantially parallel to one another.

In another embodiment, the invention provides a saw blade for use with a power tool. The saw blade includes an attachment portion for coupling the saw blade to the power tool, a body including a first substantially planar surface and a second substantially planar surface opposite the first surface, a cutting portion extending along an edge of the body, and a plurality of hexagons formed on at least one of the first surface and the second surface. The plurality of hexagons are arranged in a honeycomb pattern in which at least one side of each hexagon is substantially parallel to a corresponding side of an adjacent hexagon.

In yet another embodiment, the invention provides an accessory for use with a power tool. The accessory includes an attachment portion for coupling the accessory to the power tool, a body including a first substantially planar surface and a second substantially planar surface opposite the first surface, and a cutting portion extending along an edge of the body. At least a portion of the accessory includes a honeycomb pattern defined by relief portions formed on the first substantially planar surface, and the relief portions define a plurality of hexagons and a grid positioned between the hexagons. Each of the hexagons includes a perimeter.

DETAILED DESCRIPTION

FIGS. 1 and 2illustrate a reciprocating power tool10including a blade clamp mechanism12. The illustrated reciprocating power tool10is a reciprocating saw; however, in other embodiments, the invention may include other types of power tools, such as circular saws, oscillating tools, etc. As shown inFIGS. 1 and 2, the power tool10includes a saw housing14having a forward portion16, a body portion18housing a motor20(FIG. 2), and a handle portion22. The forward portion16of the saw housing14includes a blade receiving aperture or end24that receives a saw blade26(FIG. 1), or other type of accessory, according to one embodiment of the invention, as will be described in greater detail below. The saw blade26, or accessory, is releasably coupled to a blade clamp mechanism12(FIG. 2) positioned within the saw housing14, specifically, within the receiving aperture24. In the illustrated embodiment, a boot or grip portion28is positioned over the forward portion16of the saw housing14. In this embodiment, the boot28provides a grip area30for the user and/or provides protection to the tool10. In some embodiments, the boot28is over-molded onto the forward portion16. The handle portion22includes an over-mold to define an ergonomic grip32and allows a user to hold and control the power tool10.

With continued reference toFIGS. 1 and 2, the power tool10includes a trigger-type power switch34for activating a power supply36of the tool10and a button or switch38for selecting a speed level (e.g., a high speed or a low speed) for reciprocating the saw blade26. In the illustrated embodiment, the power supply36is a rechargeable battery pack. The battery pack36is releasably coupled to the handle portion22to provide power to the power tool10, and is releasable away from and rearward of the handle portion22. In the illustrated embodiment, the battery pack36is an eighteen-volt (18V) rechargeable power tool battery pack. In other embodiments, the battery pack36may be a twelve-volt (12V), a twenty-four-volt (24V), or other various voltages. According to another embodiment, the power supply36may be an alternating current (AC) power provided via a corded plug electrically coupled to a wall outlet or any number of suitable powering options.

With reference to the cross section illustrated inFIG. 2, the reciprocating tool10also includes a drive mechanism40positioned substantially within the housing14. The drive mechanism40is coupled to the motor20and to a spindle42for transferring rotational motion of a shaft of the motor20into reciprocating motion of the spindle42along a longitudinal axis A relative to the housing14. The blade clamp mechanism12is disposed at a distal end of the spindle42for receiving the blade26. The blade clamp mechanism12secures the blade26to the spindle42for reciprocation with the spindle42in a direction B (FIG. 1) parallel to the longitudinal axis A. In other embodiments, other suitable types and configurations of blade clamp mechanisms may be employed.

The reciprocating tool10also includes a removable shoe44, illustrated inFIG. 2, operable to engage a work piece and provide stability to the tool10while cutting. The shoe44may be removed when the accessory26is attached to the blade clamp mechanism12. The shoe44acts as a stop to limit the depth of the saw blade26into the workpiece and to prevent the workpiece from engaging the saw blade26at a connection of the saw blade26to the tool10, e.g., at the blade clamp mechanism12. In some embodiments, the shoe44freely pivots about an axis to allow the user to adjust an angle at which the blade26engages the workpiece during a cut. In some embodiments, the reciprocating tool10may not include a shoe.

In other embodiments, the power tool10may include various handle constructions, drive mechanisms, blade clamp mechanisms, and power configurations. In further embodiments, the power tool10may include other types of power and speed control switches or may not include a speed control feature.

FIGS. 3-7illustrate a sheet46according to an embodiment of the invention. The sheet46is formed from a material. For example, the material may include bi-metal strip or a hardened steel. In other embodiments, other suitable materials may be employed. The blade26may be formed from the sheet46, as illustrated inFIG. 8.

The sheet46includes a first surface48(FIG. 4) and a second surface49opposite the first surface48. The first surface48and the second surface49are substantially planar. The first surface48includes a honeycomb pattern50defined by relief, or texture, in the first surface48. In the illustrated embodiment, the honeycomb pattern50includes a pattern of discrete shapes52and a grid54defined between the pattern of discrete shapes52. Each discrete shape52includes a perimeter56. In the illustrated embodiment, the discrete shapes52, and therefore the perimeters56, are hexagons. In other embodiments, other shapes, such as octagons, rectangles, pentagons, other polygons, or other shapes having curved and/or straight sides, may be employed. In some embodiments, both the first surface48and the second surface49have a honeycomb pattern50. In some embodiments, the honeycomb pattern50is aligned on the first surface48with respect to the second surface49. In other embodiments, the honeycomb pattern50is offset on the first surface48with respect to the second surface49. In yet other embodiments, only the second surface49includes the honeycomb pattern50.

The relief of the honeycomb pattern50includes raised surfaces and depressed surfaces. The relief may also include nominal surfaces. In the illustrated embodiment, the grid54is raised with respect to the pattern of discrete shapes52. As shown inFIG. 7, the grid54is raised from the surface of the discrete shapes52by about 0.001 inches. In other embodiments, the grid54may be raised from the surface of the discrete shapes52by between about 0.000 inches and about 0.005 inches. The surface of the discrete shapes52is nominal. For example, the nominal thickness of the sheet46is 0.0420 inches, but may have other thicknesses in other embodiments. The perimeters56are depressed with respect to the surface of the discrete shapes52. As shown inFIG. 7, the perimeters56are depressed from the surface of the discrete shapes52by about 0.0020 inches. In other embodiments, the perimeters56are depressed from the surface of the discrete shapes52by between about 0.000 inches and about 0.005 inches. In other embodiments, any other combinations of raised, nominal and depressed, as defined above, for the discrete shapes52, the grid54and the perimeters56may be employed. For example, the discrete shapes52may be raised, the grid54nominal and the perimeter56depressed. In yet other embodiments, some of the discrete shapes52may be raised and some of the discrete shapes52may be nominal. For example, the discrete shapes52may alternate raised and nominal in a pattern. In some embodiments, none of the features are nominal. In embodiments in which both the first surface48and the second surface49include the honeycomb pattern50, the first surface48and the second surface49may have the same type of honeycomb pattern50. In other such embodiments, the first surface48and the second surface49may have different types of honeycomb patterns50.

As illustrated inFIG. 8, the blade26, or other type of accessory for a power tool, is cut from the sheet46and includes the honeycomb pattern50(not to scale), as described above. The blade26includes an attachment portion58and a body60extending from the attachment portion58. In the illustrated embodiment, the body60and the attachment portion58are integrally formed as a single piece such that the saw blade26is a unitary structure. In other embodiments, the saw blade26may be formed from multiple pieces that are welded or otherwise secured together. The body60includes a working portion, such as a cutting edge66having teeth, for performing an operation on a workpiece. The attachment portion58includes a tang62and an aperture64. The tang62and the aperture64are configured to engage the blade clamp mechanism12to securely and releasably connect the blade26to the reciprocating tool10. In other embodiments, other types or configurations of attachment portions may be employed in order to suit the blade clamp mechanism12of the reciprocating tool10. In other embodiments, the blade26, or accessory, may be embodied as a different type of accessory or as an accessory for another type of power tool, and may include other types of attachment portions suitable for attachment to the other types of power tools, other types of bodies suitable for other functions, and other types of working portions66suitable for performing other operations on a workpiece.

In operation, an operator attaches the attachment blade26to the blade clamp mechanism12for reciprocation with the spindle42of the reciprocating tool10. The blade26reciprocates generally parallel to the longitudinal axis A of the spindle42to perform an operation on a workpiece, for example, to cut a workpiece. The honeycomb pattern50increases stiffness of the blade26to improve performance during the cutting operation.

FIGS. 9-34illustrate a reciprocating saw blade226according to another embodiment of the invention. The illustrated saw blade226is similar to the saw blade26described above with reference toFIGS. 1-8, and similar parts have been given the same reference numbers plus 200.

Referring toFIGS. 9-11, the saw blade226includes a body260, an attachment portion258for coupling the blade226to a reciprocating saw, and a raised element, or a rib element270. The body260includes a first surface248, a second surface249opposite the first surface248, and a cutting edge266having cutting teeth272. The attachment portion258includes a tang262and an aperture264. In the illustrated embodiment, the attachment portion258is angled relative to the body260by a tang angle A (FIG. 10). In other embodiments, the tang angle A may be larger or smaller.

As shown inFIGS. 9-11, the rib element270is formed as three substantially parallel ribs278extending along the attachment portion258. As shown inFIGS. 9-11, each rib278is a flat, elongated ridge and is formed by displacing material in the blade body260from the first surface248toward the second surface249. The ribs278may be pressed from either side, or may alternate such that one rib278is pressed from one side of the blade226and another rib278is pressed from the opposite side. In other embodiments, the rib278may be formed by adding material to one side of the blade body260. In addition, each rib278includes a first portion282that is substantially parallel to the attachment portion258and a second portion286that is substantially parallel to the body260. Stated another way, the first portion282is angled relative to the second portion286by the tang angle A.

In a further embodiment illustrated inFIGS. 12 and 13, the first portions282a,282b,282cof the ribs278are substantially parallel to one another. However, as shown inFIG. 13A, the outermost ribs278a,278c(i.e., the ribs278proximate the edges of the blade226) include intermediate portions284a,284cextending away from one another. In the illustrated embodiment, the intermediate portions284a,284cextend in a direction that is substantially parallel to an edge of the blade body260. The second portions286a,286cof the outermost ribs278a,278cextend in a direction that is substantially parallel to one another, while the second portion286bof the interior rib278bextends parallel to the first portion282b. Stated another way, the ribs278that are proximate each edge of the blade226are shaped to follow the profile of the edge of the attachment portion258and at least a portion of the body260. In the illustrated embodiment, the ribs278are spaced apart by about 0.07 inches, and the outermost ribs278a,278care spaced about 0.045 inches from the edge of the blade226. In other embodiments, the ribs278are spaced apart by about 0.06 inches, and the outermost ribs278a,278care spaced about 0.04 inches from the edge of the blade226.

In the embodiment illustrated inFIG. 13D, each rib278defines a ridge280, perimeter56athat is depressed with respect to the first surface248of the blade226, and a perimeter56bthat is raised with respect to the second surface249. Each ridge280is raised from the second surface249of the blade226by about 0.015 inches. In other embodiments, each ridge280may be raised from the second surface249of the blade226by between about 0.013 inches and about 0.017 inches. In still other embodiments, each ridge280may be raised from the second surface249by a distance that is approximately half the thickness of the blade226.

As shown inFIG. 13D, the outer dimension of each perimeter56ais about 0.09 inches, while the inner dimension of the perimeter56ais about 0.05 inches. In other embodiments, the outer dimension is about 0.10 inches and the inner dimension is about 0.06 inches, such that the perimeter56ahas a width of about 0.02 inches. In addition, in the embodiment ofFIG. 13D, the outer dimension of each perimeter56bis about 0.07 inches and each ridge280has a width of about 0.03 inches. In other embodiments, the outer dimension of the perimeter56bis about 0.08 inches and the width of the ridge280is about 0.04 inches. In still other embodiments, each perimeter56a,56band each ridge280may be wider or narrower, and each rib278may be sized differently from the other ribs278.

In still other embodiments, the ribs278may be straight (FIGS. 14 and 15) or have portions that are angled relative to one another by an angle that is larger or smaller than the tang angle A. Furthermore, it is evident from comparingFIGS. 14 and 15that that the rib element270may be formed on many types of saw blades, including types other than the saw blade types shown in the drawings.

Referring now to the embodiments shown inFIGS. 16-20, the first portion282of each rib278may be angled relative to the first portions282of the other ribs278, while the second portions286of the ribs278may be joined together.

In still other embodiments, the rib element270may be formed as a single rib278(FIGS. 21 and 22), or it may be formed as a series of aligned ribs278positioned end-to-end and extending along the length of the body260of the blade226(FIGS. 23 and 24). Alternatively, the rib element270may be formed as a single rib278extending between the attachment portion258and a point that is more than halfway along the length of the blade body260(FIGS. 25 and 26), or it may be formed as a single rib278extending only along a portion of the blade body260(FIG. 27). In a further alternative (FIGS. 28 and 29), the rib element270includes three ribs278, wherein a first rib278aextends along a length of the cutting edge266, a second rib278bextends from the attachment portion258and substantially along the length of the body260, and a third rib278cextends along an edge of the body260opposite the cutting edge266. Finally, the rib element270may be formed as a single groove or rib278extending the full length of the blade226, between an edge adjacent the attachment portion258and an edge proximate an opposite end of the body260(FIGS. 30-32), or a single groove278extending the length of the blade226proximate a back edge of the body260(FIGS. 33-34).

Similar to the honeycomb pattern50described above, the rib element270provides additional rigidity to the blade body260to resist unintentional bending of the saw blade226, especially in the attachment portion258. The added rigidity reduces deformation of the saw blade226, improving the working life of the blade226and insuring that the cutting edge266remains straight to provide a cleaner cut.

Further, when the blade226is received within a blade clamp mechanism of a reciprocating saw, and in particular a slot in a saw spindle, the rib element270provides a tighter fit in the spindle. The rib element270takes up more room in the slot, preventing twisting of the blade226within the spindle. For example, the nominal portion of the saw blade226, and more specifically, of the attachment portion258, may have a nominal thickness between about 0.019 inches and about 0.062 inches, and the slot in the saw spindle may have a width of about 0.070 inches. As such, the rib element270has a thickness of between about 0.008 inches and about 0.051 inches, depending on the nominal thickness of the attachment portion258. In other words, the thickness of rib element270is less than or equal to the difference between the width of the slot in the saw spindle and the nominal thickness of the attachment portion258. Preferably, the rib element270has a thickness of up to about 0.043 inches.

As described above, the rib element270can be incorporated into various types of saw blades. Referring toFIGS. 35 and 36, the blade226includes a cutting edge266and a tang262that is received by the clamp20to couple the blade226to the reciprocating saw. The cutting edge266includes cutting teeth272that extend along the length of the cutting edge266. The tang262includes a first tang member288A, a second tang member288B, a top edge290, a bottom edge294, and a back edge298. A semi-circular aperture302is located on the top edge290and a semi-circular aperture306is also located on the bottom edge294. A generally U-shaped aperture310opens to the back edge298. The locking aperture264extends through the blade226from side to side. Similar to the embodiment described with respect toFIGS. 12 and 13above, the first portion of the ribs278are substantially parallel to one another, although the second portions286extend away from each other and extend parallel to an edge of the body260of the blade226.

FIGS. 37-42illustrate a reciprocating saw blade426according to another embodiment of the invention. The illustrated saw blade426is similar to the saw blade26described above with reference toFIGS. 1-8, and similar parts have been given the same reference numbers plus 400.

Referring toFIG. 37, the saw blade426includes a body460defining a longitudinal axis514, an attachment portion458for coupling the blade426to a reciprocating saw, and a spring portion518. The body460includes a first surface448, a second surface449opposite the first surface448, and a cutting edge466. The attachment portion458includes a tang462and an aperture464. In the illustrated embodiment, the attachment portion458is angled relative to the body460by a tang angle A. In other embodiments, the tang angle A may be larger or smaller.

As shown inFIGS. 38 and 39, the spring portion518is coupled to (e.g., formed at) a portion of the body460between the ends of the blade426. The spring portion518includes a slot530and a spring element534. The slot530extends between the spring element534and a back edge538of the blade426, and the slot530is substantially perpendicular to the longitudinal axis514. In other embodiments, the slot530may be oriented at an angle other than 90° with respect to the longitudinal axis514. The spring element534is positioned between the back edge538and the cutting edge466. In the illustrated embodiment, the spring element518is approximately halfway between the back edge538and the cutting edge466.

In the embodiment illustrated inFIG. 38, the spring element534includes an opening542defining an inner perimeter546and three arms550. Each arm550extends from a point on the inner perimeter546to a center of the opening542, where the arms550join together. In the illustrated embodiment, the arms550have an arcuate shape and are angularly spaced apart by about approximately 120°. In other embodiments, the spring element534may include fewer or more than three arms550. Also, the arms550and the slot530may have other shapes or may be arranged in other positions.

Generally, the slot530and the opening542are formed by removing material from the blade426, creating a stress concentration in the areas near the slot430and spring element534and thereby reducing the stress on the cutting teeth. The removed material (i.e., the slot530and the opening542) causes the body460to yield more easily, making the body460more flexible. The arms550strengthen the spring portion518of the blade426by distributing stresses throughout the body460, increasing the nominal stiffness of the blade426. This stiffness creates a spring effect.

During operation, the saw blade426is reciprocated in a cutting direction522(FIG. 37) and a return direction526(FIG. 37) to cut through a work piece. In some embodiments, the blade426is used to cut through work pieces composed of wood having nails extending through or embedded therein. Referring toFIG. 39, when the blade426encounters a nail or other obstruction during a cutting operation, the reaction force on the end of the blade426opposite the attachment portion458overcomes the nominal stiffness of the spring element534. The blade426flexes such that the end of the blade426opposite the attachment portion458pivots about the opening542and moves toward the attachment portion458. The arms550absorb the reaction force and distribute the stress through the body460, causing the end of the body460to rebound and move away from the slot530. This brings the cutting edge466back into engagement with the work material.

The flexing movement of the body460about the opening542relieves dynamic loading on the cutting teeth by distributing the stress throughout the blade body460. The movement also creates various cutting angles and provides different contact surfaces between each tooth and the work surface. This distributes the amount of wear more evenly throughout the cutting edge466, extending the useful life of the blade426and improving cutting time.

FIGS. 40-42illustrate a reciprocating saw blade626according to another embodiment of the invention. The illustrated saw blade626is similar to the saw blade426described above with reference toFIGS. 37-39, and similar parts have been given the same reference numbers, plus 200. The saw blade626includes a body660defining a longitudinal axis714, an attachment portion658for coupling the blade626to a reciprocating saw, and a spring portion718. The body660includes a first surface648, a second surface649opposite the first surface648, and a cutting edge666.

Referring toFIG. 41, the spring portion718is positioned proximate (i.e., formed at) a back edge738of the blade626, and the slot730is positioned proximate (i.e., formed at) the cutting edge666of the blade626. In addition, the opening742of the spring element734is elongated and extends substantially perpendicular to the longitudinal axis714. The spring element734includes one arm750having an arched shape and extending across the opening742. In other embodiments, the arm750may have other shapes, and may be asymmetrical with respect to a line extending longitudinally through the center of the opening742.

As in the embodiment shown inFIGS. 37-39, the slot730and the opening742are formed by removing material in the body660, creating a stress concentration in the area of the spring element734. The stress is absorbed by the arm750and distributed through the body660, relieving stress on the cutting teeth. In further embodiments, the spring element734may include multiple arms750extending entirely or partially across the opening742. The arm750and the slot730may have other shapes or may be arranged in other positions.

FIGS. 43-45illustrate a reciprocating saw blade826according to another embodiment of the invention. The illustrated saw blade826is similar to the saw blade426described above with reference toFIGS. 37-39, and similar parts have been given the same reference numbers plus 400.

Referring toFIGS. 43 and 44, the saw blade826includes a body860defining a longitudinal axis914(FIG. 44), an attachment portion858for coupling the blade826to a reciprocating saw, and a flexible portion962. The body860includes a first surface848, a second surface849opposite the first surface848, and a cutting edge866. The attachment portion858includes a tang862and an aperture864.

The flexible portion962is positioned proximate (i.e., formed at) a portion of the body860between the attachment portion858and an end opposite the attachment portion858. The flexible portion962includes a flexible member or bridge member966, a follower member970, and a slot974defined between the bridge member966and the follower member970. The bridge member966defines a portion of a back edge938of the blade826. The follower member970includes a first end982, which is coupled to the body860, and a second end986that is free, or not coupled to the body860. The follower member970defines a portion of the cutting edge866.

The slot974includes a first leg990and a second leg994. The first leg990extends from a position near the juncture of the cutting edge866and the body860. The first leg990extends toward the back edge938at an angle relative to the longitudinal axis914, and extends toward the end of the body860opposite the attachment portion858. In the illustrated embodiment, the angle is approximately 45°. The first leg990ends at a position between the back edge938and the cutting edge866. In the illustrated embodiment, the first leg990extends about halfway through the body860. The second leg994extends from the end of the first leg990away from the attachment portion858in a direction that is substantially parallel to the longitudinal axis914. In other embodiments, the second leg994may be oriented at an angle with respect to the longitudinal axis914. In the illustrated embodiment, the ratio of the length of the saw blade826to the length of the second leg994is approximately 8.6:1. In other embodiments, the ratio may be lower, such as approximately 4:1. The slot974may be formed in the blade body860as part of an operation for stamping the blade body860, or may be cut using a laser-cutting process after the blade body860is formed.

FIGS. 44 and 45illustrate how the bridge member966and the follower member970bend independently of one another. When the saw blade826is positioned near an inside corner (FIG. 45), for example, the inside wall998contacts the forward portion16of the reciprocating saw10, causing the saw blade826to bend along the wall998. Because the bridge member966is coupled to the body860, the bridge member966bends with the saw blade826against the wall998. The follower member970, however, is not coupled to the body860at the second end986, and therefore the follower member970remains aligned with the first end of the body860opposite the attachment portion858. Since the first end of the body860is bent in a manner that is substantially parallel to the wall998, the follower member970is flush with the inside wall998. The attachment portion858, the bridge member966, and the back edge938bend away from the longitudinal axis914and out of a plane defined by the second surface849of the body860. This permits the cutting edge866to remain flush against the inside wall998, even though the bridge member966is bent. As the saw blade826reciprocates, the cutting edge866cuts the work piece along a line that is flush with the inside wall998.

In another embodiment, the saw blade826may incorporate a flexible portion as described above with respect toFIGS. 43-45as well as a honeycomb pattern or a rib element270as described above with respect to any ofFIGS. 1-34.