Patent Publication Number: US-2020290130-A1

Title: Accessories for oscillating power tools

Description:
RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 120 as a continuation of U.S. patent application Ser. No. 16/278,348, filed Feb. 18, 2019, titled “Accessories for Oscillating Power Tools,” which is a continuation of U.S. patent application Ser. No. 15/406,940, filed Jan. 16, 2017, titled “Accessories for Oscillating Power Tools.” Each of the foregoing applications is incorporated by reference. 
    
    
     TECHNICAL FIELD 
     This application relates to accessories (such as cutting tools, saw blades, and sanding tools) for oscillating power tools. 
     BACKGROUND 
     Oscillating power tools generally have a motor, an output shaft, and a transmission that connects the motor to the output shaft and converts rotary motion of the motor to oscillating motion of the output shaft. The output shaft is coupled to an accessory attachment mechanism that is used to removably attach various types of accessories, such as cutting tools, saw blades, and sanding tools, to the output shaft. Different brands of oscillating power tools tend to have different, often proprietary, accessory attachment mechanisms. It is desirable to have oscillating accessories with an attachment portion that can be attached to a multitude of different brands of oscillating power tools. 
     SUMMARY 
     In an aspect, an accessory for coupling to an attachment mechanism of an oscillating power tool includes a working end portion and an attachment portion. The working end portion defines and extends along a working axis and configured to perform an operation on a workpiece. The attachment portion is coupled to the working end portion and includes a top wall, a bottom wall spaced apart from the top wall, and a peripheral wall extending from the top wall to the bottom wall at least partially around the top wall to form at least a portion of a polygonal shape. A generally U-shaped opening is defined in the top wall, extends along an attachment axis at an angle to the working axis, has a central portion at a center of the attachment portion, and is open to a gap in the peripheral wall. A plurality of radial openings is defined in the top wall and arranged between the U-shaped opening and the peripheral wall. The peripheral wall, the U-shaped opening, and the plurality of radial openings are configured to couple the attachment portion to at least two different configurations of accessory attachment mechanisms on different brands of oscillating power tools. 
     Implementations of this aspect may include one or more of the following features. The working end portion may include at least one of a cutting edge, a saw blade, a sanding surface, and an abrading surface. Each of the radial openings may extend in a direction radially outward from the central portion. The radial openings may be spaced equiangularly in a circumferential direction around the central portion. The radial openings may include a first plurality of radial openings in communication with the central portion of the U-shaped opening and a second plurality of radial openings not in communication with the U-shaped opening. The first plurality of radial openings may include a first radial arm slot extending from the central portion along the working axis, a second radial arm slot extending from the central opening at approximately 90° from the working axis, and a third radial arm slot extending from the central opening at approximately 180° from the working axis. The second plurality of radial openings may include a first pair of radial openings spaced radially from the central portion and between the first and second radial arm slots, and a second pair of radial openings spaced radially from the central portion and between the second and third radial arm slots. The first pair of radial openings may be at angles of approximately 30 degrees and approximately 60 degrees to the working axis, and the second pair of radial openings may be at angles of approximately 120 degrees and approximately 150 degrees to the working axis. The second plurality of openings may further include a third pair of radial openings spaced radially from the central portion between the first radial arm slot and the U-shaped opening. The third pair of radial openings may be at angles of approximately 30 degrees and approximately 60 degrees to the working axis. 
     The attachment axis may be at an obtuse angle (e.g., between approximately 120 degrees and approximately 150 degrees) to the working axis. The peripheral wall may include a plurality of sidewalls that form the portion of the polygonal shape. The plurality of sidewalls may form at least a portion of a star shape, with adjacent sidewalls joined to form outer vertices and inner vertices of the portion of the star shape. Each of outer vertices may be aligned with one of the radial openings. The portion of the star shape may comprise a portion of a 12-pointed star. For example, the sidewalls may define at least 7 outer vertices of the portion of the 12-pointed star. Each sidewall may be inclined inward from the bottom wall toward the top wall at an angle, or may be substantially perpendicular to the top wall and to the bottom wall. The U-shaped opening may include a pair of opposing chamfers tapering outward from each other to the gap. 
     The angle of the attachment axis may be arranged so that an oscillating power tool having two opposed legs that expand along a power tool axis to engage an oscillating accessory will both engage the at least a portion of the top wall when the working axis of the accessory is aligned with and perpendicular to the tool housing axis. For example, the attachment axis may be at an angle of approximately 120° to approximately 150° to the tool axis. 
     In another aspect, an accessory is configured to be coupled to a first attachment mechanism of a first oscillating power tool that includes a central projection and plurality of circumferentially spaced projections radially outward from the central projection, and configured to be coupled to a second attachment mechanism of a second oscillating power tool having two opposed legs that are radially expandable along a tool axis and a circumferential wall having an internal polygonal shape. The accessory includes a working portion and an attachment portion coupled to the working portion. The working portion defines and extends along a working axis and is configured to perform an operation on a workpiece. The attachment portion includes: (a) a top wall; (b) a bottom wall spaced apart from the bottom wall; (c) a peripheral wall extending between the top wall and the bottom wall and at least partially around the top wall to form at least a portion a polygonal shape that corresponds to the polygonal shape of the second attachment mechanism; (c) a generally U-shaped opening defined in the top wall, the U-shaped opening extending along an attachment axis at an obtuse angle to the working axis, having a central portion at a center of the attachment portion, and open to a gap in the peripheral wall; and (d) a plurality of radial openings defined in the top wall and arranged between the U-shaped opening and the peripheral wall. The obtuse angle and the radial openings are arranged so that the U-shaped opening receives the central projection and at least a portion of the radial openings receive at least a portion of the projections when the attachment portion is coupled to the first oscillating power tool. The obtuse angle and the peripheral wall are arranged so that both of the opposed legs of the second oscillating power tool engage at least a portion of the top wall and the circumferential wall engages the peripheral wall when the attachment portion is retained in the second oscillating power tool with the working axis aligned with or perpendicular to the tool axis. 
     Implementations of this aspect may include one or more of the following features. The working end portion may include at least one of a cutting edge, a saw blade, a sanding surface, and an abrading surface. Each of the radial openings may extend in a direction radially outward from the central portion. The radial openings may be spaced equiangularly in a circumferential direction around the central portion. The radial openings may include a first plurality of radial openings in communication with the central portion of the U-shaped opening and a second plurality of radial openings not in communication with the U-shaped opening. The first plurality of radial openings may include a first radial arm slot extending from the central portion along the working axis, a second radial arm slot extending from the central opening at approximately 90° from the working axis, and a third radial arm slot extending from the central opening at approximately 180° from the working axis. The second plurality of radial openings may include a first pair of radial openings spaced radially from the central portion and between the first and second radial arm slots, and a second pair of radial openings spaced radially from the central portion and between the second and third radial arm slots. The first pair of radial openings may be at angles of approximately 30 degrees and approximately 60 degrees to the working axis, and the second pair of radial openings may be at angles of approximately 120 degrees and approximately 150 degrees to the working axis. The second plurality of openings may further include a third pair of radial openings spaced radially from the central portion between the first radial arm slot and the U-shaped opening. The third pair of radial openings may be at angles of approximately 30 degrees and approximately 60 degrees to the working axis. 
     The obtuse angle may be between approximately 120 degrees and approximately 150 degrees. The peripheral wall may include a plurality of sidewalls that form the portion of the polygonal shape. The plurality of sidewalls may form at least a portion of a star shape, with adjacent sidewalls joined to form outer vertices and inner vertices of the portion of the star shape. Each of outer vertices may be aligned with one of the radial openings. The portion of the star shape may comprise a portion of a 12-pointed star. For example, the sidewalls may define at least 7 outer vertices of the portion of the 12-pointed star. Each sidewall may be inclined inward from the bottom wall toward the top wall at an angle, or may be substantially perpendicular to the top wall and to the bottom wall. The U-shaped opening may include a pair of opposing chamfers tapering outward from each other to the gap. The U-shaped opening and the plurality of radial openings may be arranged so that the attachment portion can be coupled to a third attachment mechanism of a third oscillating power tool 
     Advantages may include one or more of the following. The accessory may be coupled to a wide array of brands of oscillating power tools with adequate retention. These and other advantages and features will be apparent from the description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view an oscillating power tool having an embodiment of an accessory attachment mechanism. 
         FIG. 1B  a perspective view of a clamping plate of the attachment mechanism of  FIG. 1A . 
         FIG. 2A  is a perspective view of another embodiment of an attachment mechanism for an oscillating power tool. 
         FIG. 2B  is a cross-sectional view of the attachment mechanism of  FIG. 2A . 
         FIG. 3A  is a perspective view of another embodiment of an attachment mechanism for an oscillating power tool. 
         FIG. 3B  is a top view of a clamping plate of the attachment mechanism of  FIG. 3B . 
         FIG. 4A  is a perspective view of another embodiment of an attachment mechanism for an oscillating power tool. 
         FIG. 4B  is a top view of a clamping plate of the attachment mechanism of  FIG. 4B . 
         FIGS. 5A-5H  are schematic views of several embodiments of attachment mechanisms for oscillating power tools. 
         FIG. 6A  is a perspective view of an embodiment of an accessory in accordance with the present application. 
         FIG. 6B  is a top view of the accessory of  FIG. 6A . 
         FIG. 6C  is a side view partially in section of the accessory of  FIG. 6B , taken along line  6 B- 6 B. 
         FIG. 6D  is a close up top view of the attachment mechanism of the accessory of  FIG. 6A . 
         FIGS. 7A-7H  are schematic views showing coupling of the accessory of  FIGS. 6A-6D  to the attachment mechanisms for oscillating power tools of  FIGS. 5A-5H . 
         FIGS. 8A-8C  are schematic views showing coupling of the accessory of  FIGS. 6A-6D  in several rotational positions to the attachment mechanism of the oscillating power tool of  FIGS. 2A-2B and 5H . 
         FIG. 9  is a top view of another embodiment of an accessory in accordance with the present application. 
         FIG. 10  is a top view of another embodiment of an accessory in accordance with the present application. 
         FIG. 11  is a top view of another embodiment of an accessory in accordance with the present application. 
         FIGS. 12A and 12B  are perspective and side views of another embodiment of an accessory in accordance with the present application. 
         FIGS. 13A and 13B  are perspective and side views of another embodiment of an accessory in accordance with the present application. 
         FIGS. 14A and 14B  are perspective and side views of another embodiment of an accessory in accordance with the present application. 
         FIGS. 15A and 15B  are perspective and side views of another embodiment of an accessory in accordance with the present application. 
     
    
    
     In the drawings, like reference numerals refer to like features. 
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1A and 1B , in an embodiment, an oscillating power tool  12  usable with the accessories described in this application is similar to oscillating power tools sold under the brand names DEWALT® and Porter-Cable® and is described further in U.S. Pat. No. 8,925,931, which is hereby incorporated by reference. The power tool  12  includes a tool body  18  including a housing  20  that contains a motor  22  to drive an output member  24 . An output spindle  26  is coupled to the motor  22  via a transmission  25  that converts rotary motion of the motor  22  to oscillating motion of the spindle  26 . The output of the spindle  26  is coupled to an accessory attachment mechanism  10  via an output shaft  102 . 
     The accessory attachment mechanism  10  does not require the use of a separate tool to couple an accessory or blade  14   a  to the oscillating power tool (also known as a “tool-free” attachment mechanism). An exemplary tool-free attachment mechanism  10  includes a clamp assembly  30  having a first clamp member  36  fixedly coupled to the output spindle, a second clamp member  38  facing the first clamp member  36 , and a lever  32  coupled to the second clamp member  38 . The lever  32  includes a lever arm  40  with a user engagement portion  42  and a block  44 . The lever  32  further includes a pivot portion  46  having a pivot axle  48 . The second clamp member  38  includes a second clamp body  70  generally in the form of a ring having a central opening  72 . The second clamp body  70  has a second clamping surface  74  having a plurality of mounting features  76  formed thereon. In the example shown, the plurality of mounting features  76  are in the form of male projections  78 . In the particular example shown, the eight male projections  78  each have a circular cross section and a tapered shape or form. In another related embodiment, as shown in  FIG. 5B , the male projections may have an oblong, oval, or rectangular cross-section and may also be tapered. 
     Referring to  FIGS. 2A and 2B , in another embodiment, an oscillating power tool  112  usable with the accessories described in this application is similar to oscillating power tools sold under the brand name Starlock® and is described further in U.S. Patent App. Pub. Nos. 2016/0288288, 2016/0199919, and 2016/0184956, which are hereby incorporated by reference. The power tool  112  includes a tool body  118  including a housing  120  that defines a tool housing axis X. The housing  120  contains a motor (not shown, similar to motor  22 ) to drive an output member (not shown, similar to output member  24 ). An output spindle  126  is coupled to the motor via a transmission (not shown, similar to transmission  25 ) that converts rotary motion of the motor to oscillating motion of the spindle  126  extending along a driving axis  102 . The output of the spindle  126  is coupled to an accessory attachment mechanism  110 . 
     The accessory attachment mechanism  110  includes a holding device  104  that includes radially moveable first and second hook devices or opposed legs  104   a ,  104   b . The legs  104   a ,  104   b  b can be moved radially outward along a direction parallel to the tool axis to engage a central opening in an oscillating accessory. The attachment mechanism  110  also includes a torque transmission region  109  having a top planar wall  111  and a peripheral wall  113  with a plurality of sidewalls  109   a , each extending outward from the top wall  111  at an angle ϕ (e.g., an acute angle, such as approximately 20° to 22°). Adjacent sidewalls  109   a  are angled relative to one another with adjacent sidewalls joined at outer vertices  115   a  and inner vertices  115   b  to form a star shape (e.g., a 12-point star). In the illustrated embodiment, the outer vertices  115   a  of the star shape are positioned every 30° about the periphery of the peripheral wall  113 . The torque transmission region  109  is configured to engage a corresponding peripheral wall of an oscillating accessory. 
     Referring to  FIGS. 3A and 3B , in another embodiment, an oscillating power tool  200  usable with the accessories described in this application is similar to oscillating power tools sold by Bosch® and is described further in U.S. Pat. No. 8,151,679, which is hereby incorporated by reference. The oscillating power tool  200  includes an accessory attachment mechanism  210  that requires the use of a separate tool such as a screwdriver or wrench to couple a blade  214  to the oscillating power tool. Such an exemplary accessory attachment mechanism  210  includes a clamping face  218  that is fixedly attached to an output spindle  220  to oscillate with the spindle  220 , and a threaded bolt  242  that can be removably received (using a separate tool) in a threaded bore (not shown) in the spindle  220  and/or in the clamping face  218 . The accessory attachment mechanism  210  may optionally include a washer  224  received between the head of the bolt  242  and the clamping face  218 . The clamping face  218  includes a plurality of mounting features or form-locking elements in the form of radial lugs or projections  212  configured to engage with a plurality of corresponding recesses or openings  212 ′ in an oscillating blade or accessory  214 . The lugs or projections  212 ′ may have a trapezoidal shape or cross-section. To couple an oscillating blade  214  to the oscillating power tool, the bolt  242  and washer  224  are removed from the threaded bore, the oscillating blade  214  has its recesses or openings  212 ′ aligned with the projections  212  on the clamping face  218 , and the bolt  242  and washer  224  are reattached to the threaded bore to hold the oscillating blade  214  between the bolt  242  and the clamping face  218 . The oscillating blade  214  can be removed by removing the bolt  242  and/or washer  224  from the threaded bore. 
     Referring to  FIGS. 4A and 4B , in another embodiment, an oscillating power tool  310  usable with the accessories described in this application is similar to oscillating power tools sold by Fein® and is described further in U.S. Pat. No. 6,796,888, which is hereby incorporated by reference. The oscillating power tool  310  includes an accessory attachment mechanism  312  that requires the use of a separate tool such as a screwdriver or wrench to couple a blade to the oscillating power tool. Such an exemplary accessory attachment mechanism  312  includes a clamping face  322  that is fixedly attached to an output spindle  316  extending along an output axis  318 . The clamping face  322  is configured to oscillate with the spindle  316 , and a threaded bolt  330  that can be removably received (using a separate tool) in a threaded bore (not shown) in the spindle  316  and/or in the clamping face  322 . The clamping face  322  includes a plurality of mounting features in the form of radial projections  328  configured to engage with a plurality of corresponding recesses or openings in an oscillating blade or accessory. The projections  328  each may have rounded tips or bulges  326  and may be joined by curved edges  327 . To couple an oscillating accessory to the oscillating power tool, the bolt  330  are removed from the threaded bore, the oscillating accessory has its recesses or openings aligned with the projections  328 , and the bolt  330  is reattached to the threaded bore to hold the oscillating accessory between the bolt  330  and the clamping face  322 . The oscillating accessory can be removed by removing the bolt  330  from the threaded bore. 
       FIGS. 5A-5F , common accessory attachment mounting features for various different brands of oscillating power tools are illustrated (both the tool and tool-free types). In one aspect, this application discloses embodiments of oscillating accessories that adaptable to be coupled to the accessory attachment mechanisms on more than one of these different types of mounting features. 
     For example,  FIG. 5A  illustrates a projection pattern on the clamping face  70  of Porter-Cable® branded oscillating power tools, as illustrated above in  FIGS. 1A and 1B . The projection pattern includes eight round projections  78   a - 78   h  arranged clockwise about a central opening  72  at angles of 0, 60, 90, 120, 180, 240, 270, and 300 degrees, respectively, relative to an imaginary vertical line  74  extending from the central hole  72 .  FIG. 5B  illustrates a projection pattern on a clamping face  70 ′ of DEWALT® branded oscillating power tools. The projection pattern includes eight oblong or rectangular projections  78   a ′- 78   h ′ arranged clockwise about a central opening  72 ′ at angles of 0, 60, 90, 120, 180, 240, 270, and 300 degrees, respectively, relative to an imaginary vertical line  74 ′ extending from the central hole  72 ′.  FIG. 5C  illustrates a projection pattern on a clamping face  400  of Mastercraft® branded oscillating power tools (e.g., the Mastercraft® 054-1266-4 oscillating tool), which includes four round projections  400   a - 400   d  arranged clockwise about a central circular projection  402  at angles of 0, 90, 180, and 270 degrees, respectively, relative to an imaginary vertical line  404  extending from the central projection  402  through the projection  400   a .  FIG. 5D  illustrates a projection pattern on a clamping face  218  of Dremel®, Bosch®, Milwaukee®, and Skil® branded oscillating power tools (e.g., the Dremel® Multi-Max MM-20 oscillating tool, the Bosch® MX25EC-21 Multi-X oscillating tool, the Milwaukee® 2426-22 oscillating tool, and the Skil® 1400-02 oscillating tool) similar to the Bosch® branded products disclosed above in  FIGS. 3A and 3B . This projection pattern includes twelve trapezoidal or oblong projections  212   a - 2121  arranged clockwise every 30 degrees about a central opening  220 , relative to an imaginary vertical line  204  extending from the central opening  220  through projection  212   a.    
       FIG. 5E  illustrates a projection pattern on a clamping face  322  of Fein® branded oscillating power tools (e.g., the Fein® FMM-250 oscillating tool) similar to the Fein® products disclosed above in  FIGS. 4A and 4B . This pattern includes a central, circular projection  327 , and four radial projections  328   a - 328   d  extending radially outward from the central projection  327  clockwise at angles of 0, 90, 180, and 270 degrees, respectively, relative to an imaginary vertical line  304  extending from the central projection  327  through projection  328   a .  FIG. 5F  illustrates a projection pattern on a clamping face  500  of Craftsman® branded oscillating power tools (e.g., the Craftsman® 2702 oscillating tool), which includes a four radial projections  500   a - 500   d  extending radially outward, and arranged clockwise about a central point  502  at angles of 0, 90, 180, and 270 degrees, respectively, relative to an imaginary vertical line  504  extending from the central point  502  through the radial projection  500   a .  FIG. 5G  illustrates a projection pattern on a clamping face  600  of Ridgid® branded oscillating power tools (e.g., the Ridgid® R26800 oscillating tool), which includes a central, circular projection  602 , and four radial projections  600   a - 600   d  extending radially outward from the central projection  602  clockwise at angles of 0, 90, 180, and 270 degrees, respectively, relative to an imaginary vertical line  604  extending from the central projection  602  through the radial projection  600   a .  FIG. 5H  illustrates a projection pattern on Starlock® branded oscillating power tools similar to the Starlock® products disclosed above in  FIGS. 2A and 2B . This pattern includes two radially expandable central legs  104   a ,  104   b  that move radially outward along a line L that is parallel to the tool axis. The pattern also includes a peripheral wall  113  with a plurality of sidewalls  109   a  that together define a star shape (e.g., a 12-point star with outer vertices  115   a  positioned every 30 degrees about the peripheral wall  113 ). 
     Referring to  FIGS. 6A-6F , an embodiment of an oscillating accessory  700  according to the present application includes a working end portion  702  and an attachment portion  704 . The working end portion  702  defines and extends along a working end axis W and is configured to perform an operation on a workpiece. The working end portion comprises a working end  701  that may comprise, e.g., one or more of a cutting edge, a saw blade, a sanding surface, or an abrading surface. 
     The attachment portion  704  is coupled to a rear end portion  703  of the working end portion  702  and is configured to be coupled to all of the different configurations of accessory attachment mechanisms on the brands of oscillating power tools described above. The attachment portion  704  includes a top planar wall  706  and a bottom planar wall  708  that are generally parallel to and offset from each other and from the working end portion  702 . A peripheral wall  710  extends at least partially around the attachment portion between the top wall  706  and the bottom wall  708  and that has at least a portion of a polygonal shape. For example, the peripheral wall  710  includes a plurality of sidewalls  712 , each inclined inward from the bottom wall  708  toward the top wall  706  at an angle α (e.g., an acute angle, such as approximately 20° to 22°) so that the bottom wall  708  is disposed radially outward from the top wall  706 . Adjacent sidewalls  712  are also angled relative to one another with adjacent sidewalls joined at outer vertices  714  and inner vertices  716  to form the portion of a star shape. In an embodiment, adjacent sidewalls  712  are angled to each other by alternating inward angles βi (e.g., an obtuse angle, such as approximately 149° to 151°) and outward angles βo (e.g., an obtuse angle, such as approximately 119° to 121°) and form a portion (e.g., at least 7 points or 9 points) of a 12 point star shape. 
     The top wall  706  defines a generally U-shaped opening  720  extending along an attachment portion axis A that is at an angle θ to the working end axis W (e.g., an obtuse angle such as approximately 120° to 150°). The U-shaped opening  720  and its angle θ relative to the working end axis W is a critical feature of the oscillating accessory for reasons that will become apparent below. The U-shaped opening  720  has a semi-circular central portion  720  bounded by a curved edge  721  at a center C of the attachment portion  704 . The U-shaped opening  720  also has a posterior portion  724  extending from the central portion  722  along the attachment portion axis A bounded by straight parallel edges  723  and by radial outward chamfers  725   a ,  725   b  and open to a gap  726  in the top wall  706  and a gap  727  in the peripheral wall  712  and the bottom wall  708 . It should be noted that the gap  726  in the top wall  706  has a first width w1 that is smaller than a second width  22  of the gap  727  in the peripheral wall  712  and the bottom wall  708 . The larger width w2 of the gap  727  in the peripheral wall  712  enables clamping bolts of the aforementioned oscillating power tools to be inserted beneath the top wall  706  without removing the clamping bolt from the oscillating power tool, while the smaller width w1 of the gap  726  in the top wall  706  enables a larger surface area of the top wall  706  to engage the projection pattern on the clamping face of the oscillating power tool. 
     The top wall  706  also defines a plurality of a radial openings  730  arranged between the U-shaped opening  720  and the peripheral wall  710 , each extending in a direction radially outward from the center C of the central portion  722 . The plurality of radial openings  730  include a first plurality of radial openings that include three radial arm slots  732   a - 732   c . The radial arm slots  732   a - 732   c  are in communication with and extend radially outward from the central portion  722  of the U-shaped opening  720 . The radial arm slots  732   a - 732   c  are positioned at approximately 0°, 90°, and 180°, respectively, in a counterclockwise direction relative to the working end axis W. If, as shown in the drawings, the attachment portion axis A is at an angle θ of approximately 150° to the working end axis W, then the radial arm slots  732   a - 732   c  are at approximately 120°, 210°, and 330°, respectively, in a counterclockwise direction from the attachment portion axis A. More generally, it can be said that all of the radial arm slots  732   a - 732   c  are either parallel to or perpendicular to the working tool axis W, and are all non-parallel or non-perpendicular to the attachment axis A. Each radial arm slot  732   a - 732   c  has a pair of straight, parallel side edges  733   a  joined by a curved outer edge  733   b  to form a generally oblong shape. However, the radial arm slots can have other configurations such as rectangular or partially oval. 
     The plurality of radial openings  730  also include a second plurality of radial openings that include a first pair of radial openings  734   a ,  734   b  spaced radially from the central portion  722  and between the first and second radial arm slots  732   a ,  732   b , a second pair of radial openings  734   c ,  734   d  spaced radially from the central portion  722  and between the second and third radial arm slots  732   b ,  732   c , and a third pair of radial openings  734   e ,  734   f  spaced radially from the central portion  722  and between the U-shaped opening  720  and the first radial arm slot  732   a . The radial openings  734   a - 734   f  are positioned at approximately 30°, 60°, 120°, 150°, 300°, and 330°, respectively, in a counterclockwise direction CCW relative to the working end axis W. If, as shown in the drawings, the attachment portion axis A is at an angle θ of approximately 120° to the working end axis W, then the second plurality of radial openings  734   a - 734   f  are at approximately 150°, 180°, 240°, 270°, 60°, and 90°, respectively, in a counterclockwise direction CCW from the attachment portion axis A. More generally, it can be said that all of the second plurality of radial openings  734   a - 734   f  are all non-parallel or non-perpendicular to the working axis W. Each of the second plurality of radial openings  734   a - 734   f  has a pair of straight parallel side edges  735   a  joined by a curved outer edge  735   b  and a straight inner edge  735   c  to form a generally oblong shape. However, the second plurality of radial openings may have a different configuration such as rectangular, round, or oval. 
     The chamfered edges  725   a ,  725   b  extend outward from the posterior portion  724  of the U-shaped opening  720  in radial directions from the center C of the central portion  722 . Each chamfered edge  725   a ,  725   b  extends in a direction in which a radial opening in the top wall  706  would extend if the top wall  706  did not have the gap  726 . Chamfered edge  725   a  extends in a direction in which another of the second plurality of radial openings would extend, e.g., at an angle of approximately 210° in a counterclockwise direction CCW relative to the working end axis W. Chamfered edge  725   b  extends in a direction in which another radial arm slot would extend, e.g., at an angle of approximately 270° in a counterclockwise direction CCW relative to the working end axis W. If, as shown in the drawings, the attachment portion axis A is at an angle θ of approximately 150° to the working end axis W, then the chamfers  725   a ,  725   b  are at approximately 300° and 30°, respectively, in a counterclockwise direction CCW from the attachment portion axis A. 
       FIGS. 7A-7H  schematically illustrate how the attachment portion  704  of the accessory  700  is coupled to the clamping mechanisms of the power tools shown in  FIGS. 5A-5H  with the working end axis W aligned with the power tool housing axis X. As shown in  FIGS. 7A and 7B , when the accessory  700  is coupled to a Porter-Cable® or a DEWALT® branded power tool, the central portion  722  of the U-shaped opening  720  receives the support post  72 ,  72 ′ of the power tool, the first set of radial arm slots  732   a ,  734   b ,  734   c  receive the projections  78   a ,  78   g ,  78   e ,  78   a ′,  78   g ′,  78   e ′, the second radial openings  734   b ,  734   c ,  734   e , receive the projections  78   h ,  78   f ,  78   b ,  78   h ′,  78   f ′,  78   b ′, and the chamfer  725   b  provides clearance for and abuts the projections  78   c ,  78   c ′. As shown in  FIG. 7C , when the accessory  700  is coupled to a Mastercraft® branded power tool, the central portion  722  of the U-shaped opening  720  receives the central projection  402  of the power tool, the first set of radial arm slots  732   a ,  732   b ,  732   c  receive the round projections  400   a ,  400   d ,  400   c  of the power tool, and the chamfer  725   b  provides clearance for and abuts the round projection  400   b.    
     As shown in  FIG. 7D , when the accessory  700  is coupled to a Dremel®, Bosch®, Milwaukee®, or Skil® branded oscillating power tools, the central portion  722  of the U-shaped opening  720  receives the central projection  220  of the power tool, the radial arm slots  732   a - 732   c  and the second radial openings  734   a - 734   f  together receive the oblong or trapezoidal projections  212   a - 212   c  and  212   g - 2121 , and the chamfers  725   a ,  725   b  provide clearance for and abut projections  212   d ,  212   f . As shown in  FIG. 7E , when the accessory is coupled to a Fein® branded oscillating power tool, the central portion  722  of the U-shaped opening  720  receives the central projection  327 , the first set of radial arm slots  732   a ,  732   b ,  732   c  receive the radial projections  328   a ,  328   c ,  328   d , and the chamfer  725   b  provides clearance for and abuts the radial projection  328   b . As shown in  FIG. 7F , when the accessory is coupled to a Craftsman® branded oscillating power tool, the first set of radial arm slots  732   a ,  732   b ,  732   c  receive the radial projections  500   a ,  500   c ,  500   d , and the chamfer  725   b  provides clearance for and abuts the radial projection  500   b . As shown in  FIG. 7G , when the accessory is coupled to a Ridgid® branded oscillating power tool, the central portion  722  of the U-shaped opening  720  receives the central projection  602 , the first set of radial arm slots  732   a ,  732   b ,  732   c  receive the radial projections  600   a ,  600   c ,  600   d , and the chamfer  725   b  provides clearance for and abuts the radial projection  600   b.    
     As shown in  FIG. 7H , when the accessory  700  is coupled to a Starlock® branded oscillating power tool, the central portion  722  of the U-shaped opening receives the radially expandable legs  104   a ,  104   b  of the power tool with each of the legs  104   a ,  104   b  engaging at least a portion of the top wall  706  of the accessory  700  when the legs  104   a ,  104   b  are expanded. In addition, the at least partially star-shaped peripheral wall  710  of the accessory is received in the star-shaped peripheral wall  113  of the power tool with a majority of the sidewalls  712 , outer vertices  714 , and inner vertices  716  of the accessory  700  engaging the sidewalls  109   a , outer vertices  115   a , and inner vertices  115   b  of the power tool. 
       FIGS. 7A-7H  illustrate that the accessory  700  is universal insofar as it can be coupled to virtually all major existing brands of oscillating power tools.  FIGS. 7A-7H  show the accessory  700  being coupled to the oscillating power tools with the working end axis W of the accessory generally aligned with or parallel to the axis X of the power tool housing. However, it will be understood to one of ordinary skill in the art that the accessory  700  may be rotated and coupled to the power tools so that the working end axis W is at various other angles relative to the power tool axis X. The power tools shown in  FIGS. 7A-7D and 7H  enable the accessory  700  to be coupled to the power tool at 30° increments, while the power tools shown in  FIGS. 7E-7G  enable the accessory  700  to be coupled to the power tool at 90° increments relative to the tool housing axis X. 
     Referring to  FIGS. 8A-8C , when being coupled to the Starlock® branded oscillating power tools shown in  FIGS. 2A-2B, 5H, and 7H , the angle of the attachment axis A of the U-shaped slot  720  relative to the working axis W is a critical feature of the accessory  700 . Through extensive research, the inventors determined that oscillating power tool accessories are most often used (e.g., approximately 90% of the time) with the working axis W aligned or parallel with the tool housing axis X or perpendicular to the tool housing axis X, with the aligned or parallel position being the most common of these three positions. Therefore, the U-shaped slot  720  has been designed so that the accessory  700  may be tightly retained in the attachment mechanism  110  of the power tool when the accessory  700  is positioned at these angles. In the Starlock® power tools, the radially expandable legs  104   a ,  104   b  provide most of the axial retention of the accessory in the attachment mechanism  110 . The accessory  700  is most tightly retained if both of the radially expandable legs  104   a ,  104   b  are able to engage the top wall  706  of the accessory  700 . As shown in  FIGS. 8A-8C , by placing the attachment axis A of the U-shaped slot  720  at an obtuse angle (e.g., approximately 120° to 150°) relative to the working axis W, both legs  104   a ,  104   b  engage at least a portion of the top wall  704  when the working axis W is aligned with the tool axis X ( FIG. 8A ), at 90° counterclockwise from the tool axis X ( FIG. 8B ), and at 90° clockwise from the tool axis X ( FIG. 8C ). In contrast, if the attachment axis A of the U-shaped slot was aligned with the working axis W (as is common on existing oscillating tool accessories), then one of the legs  104   b  would not engage the top wall  704  with the accessory  700  positioned in its most commonly used position, with the working axis W aligned with the power tool axis X. Thus, the angle of the attachment axis A of the U-shaped slot is a critical feature of the accessory  700 . 
     Referring to  FIG. 9 , another embodiment of an oscillating accessory  900  according to the present application includes a working end portion  902  and an attachment portion  904 , similar to the working end portion  702  and the attachment portion  704  of the accessory  700  shown in  FIGS. 6A-8C . The working end portion  902  defines and extends along a working end axis W2 and is configured to perform an operation on a workpiece. The attachment portion  904  is coupled to a rear end portion  903  of the working end portion  902  and is configured to be coupled to all of the different configurations of accessory attachment mechanisms on the brands of oscillating power tools described above. Like the attachment portion  704 , the attachment portion  904  includes a top planar wall  906 , a generally parallel bottom planar wall  908 , and a peripheral wall  910  that extends at least partially around the attachment portion  904  between the top wall  906  and the bottom wall  908  and that forms at least a portion of a polygonal shape. For example, peripheral wall  910  includes a plurality of sidewalls  912  having a similar at least partially star shaped configuration as the side walls  712  of the peripheral wall  710 . The top wall  906  defines a generally U-shaped opening  920 , similar to the U-shaped opening  720 , extending along an attachment portion axis A2 that is at an angle θ2 to the working end axis W2 (e.g., an obtuse angle such as approximately 120° to 150°). The top wall  906  also defines a plurality of a radial openings  930  comprising three radial arm slots  932   a - 932   c  (similar to radial arm slots  732   a - 732   c ) in communication with and extending radially outward from the U-shaped opening  920 , and a second plurality of radial openings  934   a - 934   f  (similar to radial openings  734   a - 734   f ) spaced radially from the central U-shaped opening  920 . 
     The oscillating accessory  900  differs from the oscillating accessory  700  insofar as the openings in the attachment portion  904  are a mirror image of the openings in the attachment portion  704 . In the attachment portion  704 , the attachment axis A extends at an angle θ in a clockwise direction CW from the working axis W, while in the attachment portion  904 , the attachment axis A2 extends at an angle θ2 in a counterclockwise direction CCW from the working axis W2. Similarly, in the attachment portion  704 , the radial arm slots  732   a - 732   c  and the second plurality of openings  734   a - 734   f  are numbered consecutively in a counterclockwise direction CCW from the working axis W, while in the attachment portion  904 , the radial arm slots  932   a - 932   c  and the second plurality of openings  934   a - 934   f  are numbered consecutively in a clockwise direction CW from the working axis W2. 
     Since the attachment portion  904  is simply a mirror image of the attachment portion  704 , the accessory  900  is universal and can be coupled to all of the oscillating power tools, as shown in  FIGS. 5A-5H , with the coupling being a mirror image of the couplings shown in  FIGS. 7A-7H . In addition, like the accessory  700 , the accessory  900  may be rotated and coupled to the power tools so that the working end axis W is at various other angles relative to the power tool axis X (e.g., the power tools shown in  FIGS. 5A-5D and 5H  enable the accessory  900  to be coupled to the power tool at 30° increments, while the power tools shown in  FIGS. 5E-5G  enable the accessory  900  to be coupled to the power tool at 90° increments relative to the tool housing axis X). In addition, because the attachment axis A2 of the U-shaped slot  920  is at an obtuse angle (e.g., approximately 120° to 150°) relative to the working axis W2, the accessory  900  can be tightly retained in Starlock® branded oscillating power tools when the working axis W2 is aligned with or perpendicular to the tool housing axis X, since both legs  104   a ,  104   b  of the power tool will engage at least a portion of the top wall  904  in these positions, as shown in  FIGS. 8A-8C . 
     Referring to  FIG. 10 , another embodiment of an oscillating accessory  1000  according to the present application includes a working end portion  1002  and an attachment portion  1004 , similar to the working end portion  702  and the attachment portion  704  of the accessory  700  shown in  FIGS. 6A-8C . The working end portion  1002  defines and extends along a working end axis W3 and is configured to perform an operation on a workpiece. The attachment portion  1004  is coupled to a rear end portion  1003  of the working end portion  1002  and is configured to be coupled to a plurality of different configurations of accessory attachment mechanisms on brands of oscillating power tools described above. Like the attachment portion  704 , the attachment portion  1004  includes a top planar wall  1006 , a generally parallel bottom planar wall  1008 , and a peripheral wall  1010  that extends at least partially around the attachment portion  1004  between the top wall  1006  and the bottom wall  1008  and that forms at least a portion of a polygonal shape. For example, the peripheral wall  1010  includes a plurality of sidewalls  1012  having a similar at least partially star shaped configuration as the side walls  712  of the peripheral wall  710 . The top wall  1006  defines a generally U-shaped opening  1020 , similar to the U-shaped opening  720 , extending along an attachment portion axis A3 that is at an angle θ3 to the working end axis W3 (e.g., an obtuse angle such as approximately 120° to) 150° in a clockwise direction CW from the working axis W3. The top wall  1006  also defines a plurality of a radial openings  1030  similar to radial openings  730 . 
     The oscillating accessory  1000  differs from the oscillating accessory  700  insofar as all of the radial openings  1032   a - 1032   i  in the plurality of radial openings  1030  are spaced radially from the central U-shaped opening  1020 , similar to the second plurality of radial openings  734   a - 734   f  in the accessory  700 . None of the radial openings  1032   a - 1032   i  are in communication with the U-shaped opening  1020 , in contrast to the radial arm slots  732   a - 732   c  in the accessory  700 . The radial openings  1032   a - 1032   i  are evenly spaced about a circumference of the top wall  1006  (e.g., approximately every 30° about the top wall  1006 ), and are numbered in a counterclockwise direction CCW from the working axis W3. 
     The accessory  1000  is somewhat less universal than the accessories  700 ,  900  described above. The accessory  1000  can be coupled to the oscillating power tools shown in  FIGS. 5A-5D  because the radial openings can receive the projections  78   a - 78   h ,  78   a ′- 78   h ′,  400   a - 400   d , and  212   a - 212   l  of these power tools. The accessory  1000  also can be coupled to the oscillating power tool shown in  FIG. 5H  because the U-shaped opening  1020  can receive the legs  104   a ,  104   b , and the star shaped peripheral wall  1010  can be received in the star-shaped wall  113  of the power tool. However, the accessory  1000  cannot be coupled to the oscillating power tools shown in  FIGS. 5E-5G  because none of the radial openings  1032   a - 1032   i  are in communication with the U-shaped opening  1020  such that the radial openings  1032   a - 1032   i  cannot receive all of the radial projections  328   a - 328   d ,  500   a - 500   d , and  600   a - 600   d . For the power tools shown in  FIGS. 5A-5D and 5H , like the accessory  1000  may be rotated and coupled to the power tools so that the working end axis W is at various other angles relative to the power tool axis X (e.g., the at 30° increments). Finally, because the attachment axis A3 of the U-shaped slot  1020  is at a similar obtuse angle (e.g., approximately 120° to 150°) as the attachment axis A relative to the working axis W3, the accessory  1000  can be tightly retained in Starlock® branded oscillating power tools when the working axis W3 is aligned with or perpendicular to the tool housing axis X, since both legs  104   a ,  104   b  of the power tool will engage at least a portion of the top wall  1004  in these positions, as shown in  FIGS. 8A-8C . 
     Referring to  FIG. 11 , another embodiment of an oscillating accessory  1100  according to the present application includes a working end portion  1102  and an attachment portion  1104 , similar to the working end portion  1002  and the attachment portion  1004  of the accessory  1000  shown in  FIG. 10 . The working end portion  1102  defines and extends along a working end axis W4 and is configured to perform an operation on a workpiece. The attachment portion  1104  is coupled to a rear end portion  1103  of the working end portion  1102  and is configured to be coupled to a plurality of different configurations of accessory attachment mechanisms on brands of oscillating power tools described above. Like the attachment portion  1004 , the attachment portion  1104  includes a top planar wall  1106 , a generally parallel bottom planar wall  1108 , and a peripheral wall  1110  that extends at least partially around the attachment portion  1104  between the top wall  1106  and the bottom wall  1108  and that forms at least a portion of a polygonal shape. For example, the peripheral wall  1110  includes a plurality of sidewalls  1112  having a similar at least partially star shaped configuration as the side walls  1012  of the peripheral wall  1010 . The top wall  1106  defines a generally U-shaped opening  1120 , similar to the U-shaped opening  1020 , extending along an attachment portion axis A4 that is at an angle θ4 to the working end axis W4 (e.g., an obtuse angle such as approximately 120° to) 150° in a counterclockwise direction CCW from the working axis W4. The top wall  1106  also defines a plurality of a radial openings  1130  that include radial openings  1132   a - 1132   i  spaced radially from the central U-shaped opening  1120 , similar to radial openings  1032   a - 1032   i  in the accessory  1000 . 
     The oscillating accessory  1100  differs from the oscillating accessory  1000  insofar as the openings in the attachment portion  1104  are a mirror image of the openings in the attachment portion  1004 . In the attachment portion  1004 , the attachment axis A3 extends at an angle θ3 in a clockwise direction CW from the working axis W3, while in the attachment portion  1104 , the attachment axis A4 extends at an angle θ4 in a counterclockwise direction CCW from the working axis W4. Similarly, in the attachment portion  1004 , the plurality of openings  1032   a - 1032   i  are numbered consecutively in a counterclockwise direction CCW from the working axis W3, while in the attachment portion  1104 , the plurality of openings  1032   a - 1032   i  are numbered consecutively in a clockwise direction CW from the working axis W4. 
     Since the attachment portion  1104  is simply a mirror image of the attachment portion  1004 , the accessory  1100  is similarly somewhat less universal than the accessories  700 ,  900  described above. The accessory  1100  can be coupled to the oscillating power tools shown in  FIGS. 5A-5D  because the radial openings can receive the projections  78   a - 78   h ,  78   a ′- 78   h ′,  400   a - 400   d , and  212   a - 212   l  of these power tools. The accessory  1100  also can be coupled to the oscillating power tool shown in  FIG. 5H  because the U-shaped opening  1120  can receive the legs  104   a ,  104   b , and the star shaped peripheral wall  1110  can be received in the star-shaped wall  113  of the power tool. However, the accessory  1100  cannot be coupled to the oscillating power tools shown in  FIGS. 5E-5G  because none of the radial openings  1132   a - 1132   i  are in communication with the U-shaped opening  1020  such that the radial openings  1132   a - 1132   i  cannot receive all of the radial projections  328   a - 328   d ,  500   a - 500   d , and  600   a - 600   d . For the power tools shown in  FIGS. 5A-5D and 5H , like the accessory  1100  may be rotated and coupled to the power tools so that the working end axis W4 is at various other angles relative to the power tool axis X (e.g., the at 30° increments). Finally, because the attachment axis A4 of the U-shaped slot  1120  is at an obtuse angle (e.g., approximately 120° to 150°) relative to the working axis W4, the accessory  1100  can be tightly retained in Starlock® branded oscillating power tools when the working axis W4 is aligned with or perpendicular to the tool housing axis X, since both legs  104   a ,  104   b  of the power tool will engage at least a portion of the top wall  1104  in these positions, as shown in  FIGS. 8A-8C . 
     Referring to  FIGS. 12A and 12B , another embodiment of an oscillating accessory  1200  according to the present application includes a working end portion  1202  and an attachment portion  1204 , similar to the working end portion  702  and the attachment portion  704  of the accessory  700  shown in  FIGS. 6A-8C . The working end portion  1202  defines and extends along a working end axis W5 and is configured to perform an operation on a workpiece. The attachment portion  1204  is coupled to a rear end portion  1203  of the working end portion  1202  and is configured to be coupled to all of the different configurations of accessory attachment mechanisms on the brands of oscillating power tools described above. Like the attachment portion  704 , the attachment portion  1204  includes a top planar wall  1206 , a generally parallel bottom planar wall  1208 , and a peripheral wall  1210  that extends at least partially around the attachment portion  1204  between the top wall  1206  and the bottom wall  1208  and that forms at least a portion of a polygonal shape. The top wall  1206  defines a generally U-shaped opening  1220 , similar to the U-shaped opening  720 , extending along an attachment portion axis A5 that is at an angle θ5 in a clockwise direction CW to the working end axis W5 (e.g., an obtuse angle such as approximately 120° to 150°). The top wall  1206  also defines a plurality of a radial openings comprising three radial arm slots  1232   a - 1232   c  (similar to radial arm slots  732   a - 732   c ) in communication with and extending radially outward from the U-shaped opening  1220 , and a second plurality of radial openings  1234   a - 1234   f  (similar to radial openings  734   a - 734   f ) spaced radially from the central U-shaped opening  1220 . 
     For example, the peripheral wall  1210  includes a plurality of sidewalls  1212 , similar to sidewalls  712 , which are angled relative to one another with adjacent sidewalls joined at outer vertices  1214  and inner vertices  1216  to form the portion of a star shape. For example, the sidewalls  1212  may form a portion (e.g., at least 7 points or 9 points) of a 12 point star shape. The top wall  1206  has a first gap  1226 , similar to gap  726 , and the peripheral wall  1212  has a second gap  1227 , similar to gap  727 , with the first gap  1226  having a first width w1 that is smaller than a second width w2 of the second gap  1227 , to enable clamping bolts of the aforementioned oscillating power tools to be inserted beneath the top wall  1206  without removing the clamping bolt from the oscillating power tool. The oscillating accessory  1200  differs from the oscillating accessory  700  insofar as the sidewalls  1212  are not inclined inward from the bottom wall  1208  toward the top wall  1206  at an angle, but instead are substantially perpendicular to both the top wall  1206  and the bottom wall  1208 , as shown in  FIG. 12B . 
     Referring to  FIGS. 13A and 13B , another embodiment of an oscillating accessory  1300  according to the present application includes a working end portion  1302  and an attachment portion  1304 , similar to the working end portion  1202  and the attachment portion  1204  of the accessory  1200  shown in  FIGS. 12A and 12B . The working end portion  1302  defines and extends along a working end axis W6 and is configured to perform an operation on a workpiece. The attachment portion  1304  is coupled to a rear end portion  1303  of the working end portion  1302  and is configured to be coupled to all of the different configurations of accessory attachment mechanisms on the brands of oscillating power tools described above. Like the attachment portion  1204 , the attachment portion  1304  includes a top planar wall  1306 , a generally parallel bottom planar wall  1308 , and a peripheral wall  1310  that extends at least partially around the attachment portion  1304  between the top wall  1306  and the bottom wall  1308  and that forms at least a portion of a polygonal shape. The top wall  1306  defines a generally U-shaped opening  1320 , similar to the U-shaped opening  1220 , extending along an attachment portion axis A6 that is at an angle θ6 in a counter-clockwise direction CCW to the working end axis W6 (e.g., an obtuse angle such as approximately 120° to 150°). The top wall  1306  also defines a plurality of a radial openings comprising three radial arm slots  1332   a - 1332   c  (similar to radial arm slots  1232   a - 1232   c ) in communication with and extending radially outward from the U-shaped opening  1220 , and a second plurality of radial openings  1334   a - 1334   f  (similar to radial openings  1234   a - 1234   f ) spaced radially from the central U-shaped opening  1320 . 
     For example, the peripheral wall  1310  includes a plurality of sidewalls  1312 , similar to sidewalls  1212 , which are angled relative to one another with adjacent sidewalls joined at outer vertices  1314  and inner vertices  1316  to form the portion of a star shape. For example, the sidewalls  1212  may form a portion (e.g., at least 7 points or 9 points) of a 12 point star shape. The top wall  1306  has a first gap  1326 , similar to gap  1226 , and the peripheral wall  1312  has a second gap  1327 , similar to gap  1227 , with the first gap  1326  having a first width w1 that is smaller than a second width w2 of the second gap  1327 , to enable clamping bolts of the aforementioned oscillating power tools to be inserted beneath the top wall  1306  without removing the clamping bolt from the oscillating power tool. Like the sidewalls  1212 , the sidewalls  1312  are not inclined inward from the bottom wall  1308  toward the top wall  1306  at an angle, but instead are substantially perpendicular to both the top wall  1306  and the bottom wall  1308 , as shown in  FIG. 13B . 
     The oscillating accessory  1300  differs from the oscillating accessory  1200  insofar as the openings in the attachment portion  1304  are a mirror image of the openings in the attachment portion  1204 . In the attachment portion  1204 , the attachment axis A5 extends at an angle θ in a clockwise direction CW from the working axis W, while in the attachment portion  1304 , the attachment axis A6 extends at an angle θ6 in a counterclockwise direction CCW from the working axis W6. Similarly, in the attachment portion  1204 , the radial arm slots  1232   a - 1232   c  and the second plurality of openings  1234   a - 1234   f  are numbered consecutively in a counterclockwise direction CCW from the working axis W5, while in the attachment portion  1304 , the radial arm slots  1332   a - 1332   c  and the second plurality of openings  1334   a - 1334   f  are numbered consecutively in a clockwise direction CCW from the working axis W6. 
     Referring to  FIG. 14 , another embodiment of an oscillating accessory  1400  according to the present application includes a working end portion  1402  and an attachment portion  1404 , similar to the working end portion  1002  and the attachment portion  1004  of the accessory  700  shown in  FIG. 10 . The working end portion  1402  defines and extends along a working end axis W7 and is configured to perform an operation on a workpiece. The attachment portion  1404  is coupled to a rear end portion  1403  of the working end portion  1402  and is configured to be coupled to a plurality of different configurations of accessory attachment mechanisms on brands of oscillating power tools described above. Like the attachment portion  1004 , the attachment portion  1404  includes a top planar wall  1406 , a generally parallel bottom planar wall  1408 , and a peripheral wall  1410  that extends at least partially around the attachment portion  1404  between the top wall  1406  and the bottom wall  1408  and that forms at least a portion of a polygonal shape. The top wall  1406  defines a generally U-shaped opening  1420 , similar to the U-shaped opening  1020 , extending along an attachment portion axis A7 that is at an angle θ7 to the working end axis W7 (e.g., an obtuse angle such as approximately 120° to 150°) in a clockwise direction CW from the working axis W7. 
     The top wall  1406  defines a plurality of a radial openings  1432   a - 1432   i , similar to radial openings  1032   a - 1032   i , with all of the radial openings  1432   a - 1432   i  spaced radially from the central U-shaped opening  1420  and with none of the radial openings  1432   a - 1432   i  in communication with the U-shaped opening  1420 . The radial openings  1432   a - 1432   i  are evenly spaced about a circumference of the top wall  1406  (e.g., approximately every 30° about the top wall  1406 ), and are numbered in a counterclockwise direction CCW from the working axis W7. 
     For example, the peripheral wall  1410  includes a plurality of sidewalls  1412 , similar to sidewalls  1012 , which are angled relative to one another with adjacent sidewalls joined at outer vertices  1414  and inner vertices  1416  to form a portion of a star shape. For example, the sidewalls  1412  may form a portion (e.g., at least 7 points or 9 points) of a 12 point star shape. The top wall  1406  has a first gap  1426  and the peripheral wall  1412  has a second gap  1427  with the first gap  1426  having a first width w1 that is smaller than a second width w2 of the second gap  1427 , to enable clamping bolts of the aforementioned oscillating power tools to be inserted beneath the top wall  1206  without removing the clamping bolt from the oscillating power tool. The oscillating accessory  1400  differs from the oscillating accessory  1000  insofar as the sidewalls  1412  are not inclined inward from the bottom wall  1408  toward the top wall  1406  at an angle, but instead are substantially perpendicular to both the top wall  1406  and the bottom wall  1408 , as shown in  FIG. 14B . 
     Like the accessory  1000 , the accessory  1400  is somewhat less universal than the accessories  700 ,  900 ,  1200 ,  1300  described above. The accessory  1400  can be coupled to the oscillating power tools shown in  FIGS. 5A-5D  because the radial openings  1432   a - 1432   i  can receive the projections  78   a - 78   h ,  78   a ′- 78   h ′,  400   a - 400   d , and  212   a - 212   l  of these power tools. The accessory  1400  also can be coupled to the oscillating power tool shown in  FIG. 5H  because the U-shaped opening  1420  can receive the legs  104   a ,  104   b , and the at least partially star shaped peripheral wall  1410  can be received in the star-shaped wall  113  of the power tool. However, the accessory  1400  cannot be coupled to the oscillating power tools shown in  FIGS. 5E-5G  because none of the radial openings  1432   a - 1432   i  are in communication with the U-shaped opening  1420  such that the radial openings  1432   a - 1432   i  cannot receive all of the radial projections  328   a - 328   d ,  500   a - 500   d , and  600   a - 600   d.    
     Referring to  FIGS. 15A-15B , another embodiment of an oscillating accessory  1500  according to the present application includes a working end portion  1502  and an attachment portion  1504 , similar to the working end portion  1402  and the attachment portion  1404  of the accessory  1400  shown in  FIG. 14 . The working end portion  1502  defines and extends along a working end axis W8 and is configured to perform an operation on a workpiece. The attachment portion  1504  is coupled to a rear end portion  1503  of the working end portion  1502  and is configured to be coupled to a plurality of different configurations of accessory attachment mechanisms on brands of oscillating power tools described above. Like the attachment portion  1404 , the attachment portion  1504  includes a top planar wall  1506 , a generally parallel bottom planar wall  1508 , and a peripheral wall  1510  that extends at least partially around the attachment portion  1504  between the top wall  1506  and the bottom wall  1508  and that forms at least a portion of a polygonal shape. The top wall  1506  defines a generally U-shaped opening  1520 , similar to the U-shaped opening  1420 , extending along an attachment portion axis A8 that is at an angle θ8 to the working end axis W8 (e.g., an obtuse angle such as approximately 120° to 150°) in a counterclockwise direction CCW from the working axis W8. 
     The top wall  1506  also defines a plurality of a radial openings  1530  that include radial openings  1532   a - 1532   i  spaced radially from the central U-shaped opening  1520 , similar to radial openings  1432   a - 1432   i  in the accessory  1400 , with all of the radial openings  1532   a - 1532   i  spaced radially from the central U-shaped opening  1520  and with none of the radial openings  1532   a - 1532   i  in communication with the U-shaped opening  1520 . The radial openings  1532   a - 1532   i  are evenly spaced about a circumference of the top wall  1506  (e.g., approximately every 30° about the top wall  1406 ), and are numbered in a counterclockwise direction CCW from the working axis W8. 
     For example, the peripheral wall  1510  includes a plurality of sidewalls  1512 , similar to sidewalls  1412 , which are angled relative to one another with adjacent sidewalls joined at outer vertices  1514  and inner vertices  1516  to form at least a portion of a star shape. For example, the sidewalls  1512  may form a portion (e.g., at least 7 points or 9 points) of a 12 point star shape. The top wall  1506  has a first gap  1526  and the peripheral wall  1512  has a second gap  1527 , with the first gap  1526  having a first width w1 that is smaller than a second width w2 of the second gap  1527 , to enable clamping bolts of the aforementioned oscillating power tools to be inserted beneath the top wall  1506  without removing the clamping bolt from the oscillating power tool. The oscillating accessory  1500  differs from the oscillating accessory  1100  insofar as the sidewalls  1512  are not inclined inward from the bottom wall  1508  toward the top wall  1506  at an angle, but instead are substantially perpendicular to both the top wall  1506  and the bottom wall  1508 , as shown in  FIG. 15B . 
     The oscillating accessory  1500  differs from the oscillating accessory  1400  insofar as the openings in the attachment portion  1504  are a mirror image of the openings in the attachment portion  1404 . In the attachment portion  1404 , the attachment axis A7 extends at an angle θ7 in a clockwise direction CW from the working axis W7, while in the attachment portion  1504 , the attachment axis A8 extends at an angle θ8 in a counterclockwise direction CCW from the working axis W8. Similarly, in the attachment portion  1404 , the plurality of openings  1432   a - 1432   i  are numbered consecutively in a counterclockwise direction CCW from the working axis W7, while in the attachment portion  1504 , the plurality of openings  1532   a - 1532   i  are numbered consecutively in a clockwise direction CW from the working axis W8. 
     Since the attachment portion  1504  is simply a mirror image of the attachment portion  1404 , the accessory  1500  is similarly somewhat less universal than the accessories  700 ,  900 ,  1200 ,  1300  described above. The accessory  1500  can be coupled to the oscillating power tools shown in  FIGS. 5A-5D  because the radial openings can receive the projections  78   a - 78   h ,  78   a ′- 78   h ′,  400   a - 400   d , and  212   a - 212   l  of these power tools. The accessory  1500  also can be coupled to the oscillating power tool shown in  FIG. 5H  because the U-shaped opening  1520  can receive the legs  104   a ,  104   b , and the star shaped peripheral wall  1510  can be received in the star-shaped wall  113  of the power tool. However, the accessory  1500  cannot be coupled to the oscillating power tools shown in  FIGS. 5E-5G  because none of the radial openings  1532   a - 1532   i  are in communication with the U-shaped opening  1520  such that the radial openings  1532   a - 1532   i  cannot receive all of the radial projections  328   a - 328   d ,  500   a - 500   d , and  600   a - 600   d.    
     Like the accessories  700 ,  900 ,  1000 , and  1100 , the accessories  1200 ,  1300 ,  1400 , and  1500  may be rotated and coupled to the power tools of  FIGS. 5A-5H  at various other angles relative to the power tool axis X (e.g., at 30° increments or 90° increments). Also, because the attachment axes A5, A6, A7, and A8 of the U-shaped slots  1220 ,  1320 ,  1420 , and  1520  are each at an obtuse angle (e.g., approximately 120° to 150°) relative to their respective working axis W5, W6, W7, and W8, the accessories  1200 ,  1300 ,  1400 , and  1500  can be tightly retained in Starlock® branded oscillating power tools when the working axes W5, W6, W7, and W8 are aligned with or perpendicular to the tool housing axis X, since both legs  104   a ,  104   b  of the power tool will engage at least a portion of the top walls  1204 ,  1304 ,  1404 , and  1504 , as shown with respect to accessory  700  in  FIGS. 8A-8C . 
     Example embodiments have been provided so that this disclosure will be thorough, and to fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Terms of degree such as “generally,” “substantially,” “approximately,” and “about” may be used herein when describing the relative positions, sizes, dimensions, or values of various elements, components, regions, layers and/or sections. These terms mean that such relative positions, sizes, dimensions, or values are within the defined range or comparison (e.g., equal or close to equal) with sufficient precision as would be understood by one of ordinary skill in the art in the context of the various elements, components, regions, layers and/or sections being described. 
     Numerous modifications may be made to the exemplary implementations described above. These and other implementations are within the scope of the following claims.